SEWAGE INSTALLATION

The invention refers to a sewage installation, equipped with ejectors and which uses ejectors with jet of technological under-pressure water, discontinuously and with high speed, within the sewage installation circuits, for various situations that necessitate early avoidance of incipient deposition or of the clogging through washing for cleaning, or for increasing the speeds and/or accelerations for used water transportation, on certain segments of the sewage network.

A sewage installation is meant to realize the absorption, the collection, transport, processing and discharge of used waters, produced by human settlements, industrial objectives and/or meteoric waters, infiltration waters, etc.

For sewage installations, used waters means: used and black sewage, public used waters, used water from agro=zoo=technical units, used waters produced by solving the technological duties of the sewage installation, meteoric waters from rains and snows, surface waters from exterior floods, lakes, rivers, swamps, underground waters resulted from withering, drainage, infiltrated underground waters, industrial waters resulted from industrial objectives with chemical and of particles loads, different from all the others, waters containing biological special pollutants from hospitals, biological research and testing laboratories, etc.

A sewage installation technically consists mainly of collecting recipients, a network of conducts and/or channels for transportation, used water purifying and treatment stations and annex constructions (hearths, couplings, pumps, overflows, etc.).

The complexity of a sewage installation contains downstream also the evacuation of treated water into a natural emissary (river, stream, lake, sea, etc.) or an artificial emissary (tanks, ground water sheets, etc.).

There are also parts of the sewage installation, as technical annexes, the corresponding technological parts that separate and dissipate the solid and semi-solid parts, resulting from the purifying and treatment station.

A sewage installation functionally contains a part named interior sewage (in buildings, yards, etc) and a part named exterior sewage, the most extended, in which the connection with the emissary is also included.

A sewage installation that technically has separate networks for each type of water (meteoric waters, used sewage, etc.) is of separating type, and when it uses only one network for all kinds of water is of unitary type; there is also the one of a mixed type, which technologically combines these situations.

The collecting and transportation network is generally formed of hearths and conducts or/and channels, with diverse profiles in cross-section - the profile can be closed or opened.

The most used conducts are pipes with closed -circle profile, and the most used channels are with trapezoidal profile, opened on the longer side and with the smaller basis propelled on the ground.

The conducts that have been used along the time were made at various lengths and diameters, of various materials like: wood, stone, cement, asbestos-cement, concrete, cast iron, glass, armored - glass, and more recently, in the last decades (1965 - 2005), of plastic materials - the most used being polyvinyl chloride (p.v.c). The assembling of the conducts in series and in derivation, at various diameters, in various positions and forms, is made through specific components, named fittings and through masonry hearths, reinforced concrete hearths, and hearths made of plastic materials, etc.

The placement and assembling of the channels in series and derivation, at various dimensions of the profiles, in various positions and shapes is made through specific works of soil, of masonry, of concrete placing, etc., with a technical value of junction and connection, including the hearths.

There are known many sewage installations with gravity flow, with free surface on conducts/channels, realized since the Roman Empire until present without remarkable improvements.

The most sewage installations are based on gravity flow, from the collection to the emissary, that is from upstream to downstream the installation, in which purpose the mounting of the installation is made in order to continuously ensure a flow-slope contained in average between 4 %o and 15%o, depending on the size of the transported particles, on the cross-section area of the conducts or channels, on the rugosity of interior surfaces of the conducts/channels, etc.

There are also known other sewage installations, quite many, which use the gravity flow at the collecting and transporting network, until a collection hearth of a pumping station towards a purifying and treatment station, found at a long distance, and then farther, to the emissary, either through gravity flow, if that is possible, or through under pressure flow by pumping. The under pressure flow by pumping is necessary in the following main situations:

> When there must be realized a transport of used waters or other waters (meteoric, industrial, infiltration waters) at a long distance (hundreds and thousands of meters), on a routing with a gentle slope (under 4%o) or with zero slope, or even in small and medium counter-slopes (climbing) (from l%o to 10%o); or on routings with small length and counter-slopes at 90° (supplying for purifying and treatment stations, lifting from a collection hearth to another, etc.)

> When a sewage installation with gravity flow necessitates, towards downstream, higher and higher placement depths, which are economically and technologically not possible, because of other underground or over-ground works, or other situations (the crossing with the bed of a running water, phreatic water sheets, etc.) ; there is necessary an intermediate sequence of pumping, between two consecutive hearths

> When there must be done a transport of used water or other waters without lateral collecting at a higher water discharge than the one possible to realize through gravity flow, for a certain section of the transporting conduct.

> At the connection of some independent circuits/sewage networks, which use gravity flow, but are placed at different heights and the common collection is made towards the ones that are placed higher and which are closer to the purifying and treatment station and to the emissary.

In the sewage installations on the segments of under pressure flow by pumping, therefore downstream the pump, there is not the possibility of direct connection or junction of some circuits or receiving coupling with gravity flow, because of the fact that, due to the higher daN pumping pressure [1í6 ], the pumped used water flood the sewage and come cm ² out on the surface through the upstream connection hearths of the beneficiaries and this is a disadvantage and a technical problem.

The largest part of the collection and transportation network of used waters works with gravity flow and it is placed in the soil starting with a minimum frost depth and it must allow the realization of normal, medium flow slopes, depending on the water types, the size of the solid particles dragged along, transversal surface of the transportation channel (conduct, opened channel), the viscuosity of poliphasic fluids, the rugosity of the contact surface, etc.

The functioning with gravity flow, for a sewage installation of used water, of any type from collection until the purifying and treatment station and farther to the emissary, is the most economical transport situation.

Under pressure flow through pumping - on certain interposed portions of the sewage installation with gravity flow - necessitates extra costs with the energy required by the pumping, costs which are expressed in the buying price of the sewerage services, and which price is higher than in the case of the sewage installations with total gravity flow; the pumping is generally discontinuous.

The networks of some sewage installations with gravity flow, made in the historical beginnings of stone-paved opened channels and then of conducts with closed profile and buried, were realized in the neighborhood of an emissary, without having a purifying and treatment station.

By the developing of human settlement and extension in territory, the sewage installation had been endowed with purifying and treatment stations, with pumping

stations, and had benefited from improvement in materials technology field, but got to be insufficient in absorbing increased water discharge and from pollution sources more and more distanced; generally, all sewage installations remain behind the development of urban and rural settlements and of industrial objectives.

The extension of the existing sewage installations with gravity flow is limited, because they have the downstream areas well defined as investments and positions near the emissary, and the upstream areas of those installations, which have been extended before, are in a dewatering process in order to ensure the flow slope and the reduction of the placement depth of the "upstream-head" point at the depth limit of absorbing the waters from the subsoil, or the minimum frost depth.

The extension resource of an existent sewage installation with gravity flow, found in dewatering for ensuring the flow slope represents a technical problem and therefore there cannot be done connection works at potential sources of production of sewage waters, industrial or other used waters, newly set up, which function in the extra perimeter of a built network.

Another associated technical problem is given by the existent or newly extended sewage installations, which due to various reasons, have the flow slope at the limit (< 4%o) and which allow the fast appearance of the depositions and clogging situations, and therefore they necessitate often interventions of cleaning from exterior and supplementary costs; the flow slope is to the limit, either from the very beginning, through design and execution, negligent execution, or through repositioning in time (going-down) of the conducts or through other soil warping , etc.

Another technical problem for a sewage installation, which leads to the reduction of flow/transport speed, with equal or lower values than the critical flow/deposition speed (which is of 0.7 m/s) is represented either by small and rare water discharges, or the accumulations in the coupling/passing through hearths; into which more couplings with the subscribers (punctiform sources of emission of used sewage - defined as black waters) overflow. Other accumulations are due to the sequential-temporal regimen of evacuation with increased water discharges and to the fact that an alignment conduct (principal axle) for an existing or newly built sewage gets to be under gauged and cannot absorb increased water discharges. These accumulations become a hydraulic resistance and a practical criterion of deposition, through exponential increasing, of the viscosity of the carried along fluid and through the increasing of the frictions at contact

surfaces with conducts, channels and most of all, in the hearths that are disposed on the alignment.

Another technical problem for a sewage installation with gravity flow, or through pumping pressure, consists in a detrimental work regimen, by clogging and permanent blocking, because of disrespecting the quality of the water used, admitted in the public sewage network, by the entering of some substances or bodies that induce depositions or disturb the normal, hydraulic flow, through obstacles. For their dislocation, removal or destruction, there are needed either interventions with high water discharges through the visiting hearths or through the network, or interventions with other external means, in order to eliminate the produced and extended (compared to initial conditions) clogging; for example, cleaning with a vortex wheel-head hose with washing jet with high pressure water, mechanical, flexible axes of bi-axle type (steel, multi-filar, twisted cable into the tubular, exterior jacket, made of wire-wound steel, covered in plastic) with a head carrying a dragged along brush-wheel, the introduction, within the conducts, of some chains/cables, endowed from spot to spot with brushes or pneumatic elastic spheres, with a scraper-piston role, etc.

The technical problem of the depositions, that reduce the flow-section and that rise until blocking, is accentuated by the sand, rocks, mineral dust, carried along by meteoric waters, which get into the sewage; and which particles, being heavier than those found in the used sewage and black waters, are deposed, even at optimal transport speeds of these waters. In addition, these depositions are favored by the geometrical imperfections in coupling realization.

The collecting of meteoric waters is made through gravity flow, and their transportation is generally made through gravity flow, too.

In the cases when transportation is made through under pressure flow through pumps, supplementary technical problems are created by the entering of these solid, tough bodies into the pumps strainers and rotors, producing fast erosions, deteriorations and blockings of the pumps.

There are known sewage installations that, on the segment of collection and transportation with gravity flow, are endowed with constructive capacities for water washing, such as: washing hearths with water tanks and un-automatic functioning (through intervention controls from the exterior) of the type with clack seats and with chains actions; of the type with barrier valves operated with chain and washing hearths

and with automatic operating water tank, with hydraulic automation device of Passavant type, without mobile pieces.

These hearths with water tanks are mounted into the soil at the necessary depth.

The water washing from the washing hearth is practiced only at the sewage in unitary system and only for the conducts that transport sewage and black waters, for diameters of maximum 500mm and are usually mounted near - and in upstream the installation, in order for the produced water wave to wash the conduct/channel, and the utilized water volume is usually between 3 í 10 m ³ in order to ensure a washing flow lasting a few seconds, or tens of seconds (equivalent to an inrush wave).

The washing water used through these stored water hearths can be brought from lakes, rivers, wells, potable water supplying network, etc., and it is introduced through a detachable hose (in order not to contaminate the water source).

The washing activity has a certain periodicity, function of the degree of depositions in a period of time, precisely for sewage installations with a gentle slope (< 4%o) or for sewage installations with reduced and sporadic water discharge, which produce depositions.

The technical problem of these installations with washing hearths with water tank is given by the maximum level of the stored water, which must be ensured comparatively to the minimal level of evacuation towards the sewage installation; these level differences contained in average between 1.5 í 2.5 m, produce the necessary pressure and finally, the washing speeds; these level differences are more reduced as the upstream part of the installation reduces its depth, especially in the case of extensions.

At limit, they cannot be realized and technical problems in conducts washing appear; for example, in the cases when the minimal level is at the water table from the upstream hearths of the installations, found at the frost depth limit, then the maximal level of the water that is stored in the tank coincides to the minimal level, and the washing cannot be used, which makes the existence of a washing hearth with water tank useless; it is obvious that, a sewage installation, found in this situation on one of its segments, has no lateral couplings from the beneficiaries sub-soils.

Another technical problem that appears at the washing technology through washing water inrush - produced through the hearths with water tank - is the sudden rising of the hydrostatic level in the lateral couplings and which induce hydrodynamic oscillations of the water and air pillow caught between water columns, so that they can

produce backwaters in the siphons and collection areas with the throwing outside the installation of a used water quantity and the emitting of disturbing sounds and odors. The sewage installations with gravity flow and with hearths with washing water tank have interior diameters of the conducts up to 500mm; for sewage installations with diameters higher than 500mm the washing with water coming from washing tanks does not apply, because of many technical problems such as: the sudden overflow of a big water quantity in order to wash a conduct with the diameter between 500 mm and 2000 mm creates hydraulic knockings, which can destroy the conducts and especially the hearths that are disposed on the alignment; the big length of these conducts with high diameters, conducts that are generally of alignment and get out of the settlement towards the purifying and treatment station, favors the appearance of some spread waves, direct and reflected, with high kinetic energy, capable of destroying the installation; as disadvantage, there is necessary a big water tank, which, along with other problems regarding the placement and volume, must be filled with a big quantity of water that, in many cases, affects the available water discharge of other water sources from which the washing water is taken.

Collecting and alignment conducts with big diameters contained between 5O0mmí20OOmm at sewage installations with gravity flow, are not water-washed as a distinct operation compared to the biphasic flow of used waters, precisely because of the disadvantages of the technical problems from above and they offer practical criteria for depositions and clogging, through the fact that they have a gentle flow-slope, in average between 4%o - 5%o, high rugosity of the interior surfaces of conducts/tunnels, adherent pre-depositions, which persist and gradually reduce the flow section and profile, increase the frictions, reduce the flow-slope, reduce the transport speeds, and implicitly the used water discharges. A reduction of the water discharge downstream is quickly transmitted upstream and generates even the getting out of order of the installation. Obviously, these collecting conducts are periodically cleaned through interventions from the exterior, in order for them to be maintained in function.

At opened sewage installations - with opened channels at surface - which, in their majority, are entirely with gravity flow, these can be of unitary or separating type, and are for used sewage, meteoric, industrial agro-zoo-technical waters, separated or combined, and distinctively for irrigation waters.

These sewage installations have no circuits for washing with technological water (other than the one overflowed and transported, or meteoric waters contribution).

The flow slope of the opened channels is gentle, contained between 0.5%o and 3%o, and the depositions are substantial.

This opened channels cleaning is generally made with cleaning means, which move on the channel and overflow the solid parts outside the channel, on the soil, or in transport means; the absence of some washing circuits is a disadvantage in exploitation and a technical issue.

A disadvantage and another technical issue of all sewage installations with gravity flow is the absence of some auxiliary circuits which would double the collecting channels and would be set in function, either when de-clogging and washing on basic circuits are executed, or when there must be absorbed parts from excess water discharges, compared to nominal water discharges.

Regarding the conducts (channels) for collecting and transporting the meteoric waters - constituted in distinctive network in a sewage installation of separating system type - their longitudinal slope is almost identical to the longitudinal flow-slope of the network for sewage; although acceptable transportation speeds are obtained, depositions of sand, gravel, mineral sludge appear and gradually worsen the flow and produce clogging. The depositions are generally favored by low speeds, when meteoric water discharges are reduced; high or excessive water discharges also produce clogging by the contribution of a big quantity of deposition material from the soil surface and by flooding through all the hearth holes of the installation also favoring depositions in the hearths. The depositions of sand, gravel and mineral sludge are a technical issue incident at the low speed produced by water discharges with more reduced or more increases values than the nominal water discharges, for which have been designed and executed the collection and transportation of meteoric waters networks with gravity flow. The maintaining cleanings from the exterior, which are not executed in due time, accentuate the clogging, and these networks are not endowed with technical capacities of high-speed washing; their absence is a disadvantage and another technical problem. Some installation with gravity flow are endowed downstream with some hearths or tanks, which, by vacuuming produce a rising of the hydrostatic level, before its discharge into the purifying - treatment station, or even after the station, for transportation into the emissary; due to this rising of the hydrostatic level, a restoration of the hydrostatic level takes place, capable of regenerating acceptable flow speeds and this way avoiding the depositions.

The main technical issue is to maintain for a short time the vacuuming parameters; the emission of gases dissolved in the sewage waters produce the decreasing of the depression, and even cancels it, and that is why the functioning of the installation is intermittent, and working period must be correlative with high nominal water discharges and which allow a conduct filling degree of 100%; the application is for reduced lengths of the downstream segment of the installation and necessitates priming with auxiliary discharges of used water or pure waters, through a discontinuous pumping action.

The disadvantages of sewage installations with gravity flow are the depositions and clogging in conducts/channels, hearths, etc., and which are in inverse ratio to the value of the flow-slope into the longitudinal axle of the hydraulic routing; so, as the flow slope is reduced towards zero, from values contained between 4%o and 10%o, the speeds are reduced and the depositions quantities are increased, as a consequence of the reduction of the flow- speed and transported water discharge, until clogging. This situation makes not possible the extension of these installations, already existing, in the upstream part, in order to be able to absorb the extended part of a human settlement; a realized sewage installation is generally behind a settlement's necessary and development.

The upstream extension of an existent, exterior sewage installation, with gravity flow and with the maintenance of the constructive flow-slope at nominal values or even towards the accepted inferior limit (the speed, not lower than 0.7m/s) is limited by the placement in depth that is comparable to frost-depth values and is usually contained between 1.1 m í 1.4m, function of the type and humidity of the soil; the longitudinal axis of a sewage installation with gravity flow, has as a upstream point with minimal depth the frost-depth and as a downstream point with maximal depth the emissary table (obviously, placed lower than the upstream point) and the longitudinal axis slope is generally contained between 4%o - lθ%o, from which results a constructive and service length of the installation.

Another disadvantage of this sewage installation with gravity flow is the absence of a parallel flow -circuit, which to be used while de-clogging and especially to absorb increased water discharges; this last situation is found at existent installations, which have a higher number of clients, increased meanwhile than the initial one and for which it has been designed. The installation works in continuous buried regimen, does not efficiently transport and clogs; in addition, if it is in unitary system - in which meteoric

waters are included - these last ones cannot be adequately absorbed and both masses of waters come in contact until the surface of hearths and practicable level. At circuits of sewage through under pressure flow through pumping, on the segment of backwaters (in pumps downstream), there is the disadvantage and technical problem that there cannot be endowed with couplings/collection hearths, for used waters brought through gravity flow; in conclusion, this routing usually with a big length (generally, kilometers) from downstream of collecting through gravity flow towards the purifying- treatment station, is not useful to the collection of used - water sources found in territory, on the length of this routing.

The same situation also takes place through flow under the pressure of compressed air propulsion.

Sewage installation with gravity flow, endowed on certain segments of downstream (generally, near the purifying-treatment station), with a preliminary vacuum circuit, meant to produce the lifting of used water towards the collection tanks in pumping stations presents the disadvantage and technical problem that it cannot be used to do the collection and transportation of used waters, on a network with gravity flow with the actual constructive solutions, found in exploitation, because of the quick losses of pressure differences, between the atmospheric pressure and preliminary vacuum, in the hearths area, in the free-space of the conducts with reduced filling-degree, etc. The main technical problems and disadvantages of sewage installations with gravity flow for collecting sewage waters (used, sewage, meteoric, industrial waters, etc.) are:

> the deposition and clogging until putting it out of work, because of the situation produced by reducing the flow-slope on the entire alignment of the network or only on one segment/segments of its, more often continuously, so that the flowing and carrying speed gets close to the limit flowing - deposition speed, which is of 0.7m/s; the reduction of the flow-slope (pitching down) is produced through: depositions in downstream, defective technical executions, variations of the longitudinal profile of the soil compared to the reference horizontal; extensions of the network by using sub-critical slopes; negligent maintenance (rare washings and cleanings, etc.)

> the depositions and clogging until putting it out of work, because of the mass disequilibrium between the mass of the particles and bodies pulled along and the mass of necessary water, continuously; the disequilibrium is realized through : too small or too large water discharges compared to the capacity of conducts; the

ingression of the particles and bodies with high densities compared to the density of water; defective execution; the loss of tightness of wet surface in the conducts

> the necessity of high depths (5í15m) in downstream of the main collectors/collector with high length (lkm í 2km) until the first collecting tank of a pumping station; depths that result from the value of the flow-slope

Main technical problems and disadvantage of sewage installations through under pressure pumping flow are:

> the impossibility to collect through gravity flow of sewage waters, produced by another adjacent source, on the routing of pumping towards a purifying - treatment station placed at a long distance (0.5kmí2km) from the collecting network with gravity flow of a human settlement

> high energies consumed for pumping the sewage waters towards the pumping stations, due to the filling degree of 100% and implicitly to the frictions, increased proportionally to the speeds, contact surfaces, viscuosity and the friction against walls coefficients

> the utilization of some pipes with thick walls and resistant to high pumping- pressures of the sewage waters, towards the pumping-treatment stations

The purpose of the invention is to improve the dynamic of the sewage installation with gravity flow for the ones to be built, but also to vindicate and improve the existing ones, in order to allow functioning and extensions in the areas with gentle or even detrimental flow-slopes, to allow a exploitation and maintenance through local, effective washings - in semi-autonomous regimen with technological waters - which to avoid depositions and clogging; also, to allow the increasing of the transported water discharges by increasing the medium transport speeds, and for sewage installations with under pressure pumping flow, to make possible, on certain segments and in certain situations, the coupling through gravity flow network, of some local sources of used water, which have appeared and developed through lateral arrangements in territory and on a high length of the routing but also on a ground without slope.

The technical problems that the invention solved for various types of sewage installations with gravity flow are related to the technological water contribution, through devices with jets of water, which are part of the installation and which, by a discontinuous functioning allow the conducts/channels washing, the increasing of the

medium transport speeds of used waters on a given section, the leveling of the flowing water discharges; by their utilization, combined with configuration diagrams of the longitudinal profile of the alignment, they allow the extension of the installations on routings with gentle or even detrimental slopes, and for the sewage installations with under pressure pumping flow, they allow, on certain long segments and in certain situation, the absorption, through gravity flow, of some parts of its water discharge, on an auxiliary installation, which shall also allow the coupling of a great number of used water sources, usually family households, that have developed through lateral arrangements on a high length from the pumping routing and especially, scattered on a plain land.

The basic solution of the invention is the utilization of some hydrodynamic equipment/devices of ejector type, mounted on the installation, generally on piping/channels and hearths which, when supplied, discontinuously and controlled, with under pressure technological water (generally recovered from the purifying and treatment station) produce jets of waters with speeds and mechanical impulse sufficient for washing, depositions and heavy particles drag along, the increasing of the medium speed and accelerations of transporting the used water mass, and by using it together with the configuration diagrams of the longitudinal profile of alignment allow the realization of the flow at gentle slopes and without depositions, either in the conditions of a gravity flow with free surface, either in a buried regimen - through some hearths with slope restoring (opposite to the hearths with slope-breaking, in themselves known) and a "saw-toothed" longitudinal profile (inversed siphons).

There are next given in the tables 1,2, 6 known technical data from the professional literature, for parameters correlations: the slopes angles, diameters of the conducts/channels, speeds and water discharges.

Table 1. Mounting slopes for sewage conducts with sewage water and meteoric water

Table 2. Mounting slopes for sewage conducts with industrial water

Table 3. Minimal admitted slopes (i), according to the self-cleaning speed within the channels

(Vmin~ 0,7 m/s)

Table 4. Maximal speeds within closed channels

Table 5. Maximum speeds within opened channels

Table 6. Maximum water discharge and speeds within the channels, function of the h h filling degree ( — or — )

D H h - height of the water from the channel D - channel diameter H - channel height

The invention solves through the presented basic solution and through a great part of the sewage installation with gravity collection and transport, either by placing, from spot to spot on the conventional axes in slope- in themselves known - of the conducts/channels network, some ejectors with impulses that are dwelled by water jets - jets with thin walls (nappes) generally tubular- under pumping pressure through technological water supplying, generally for maintenance washing, cleaning of materials, deposed in low adherent layer, fluidization, dragging along - with various speeds and accelerations - the particles and solid and semi-solid bodies, over the limits of deposition speeds or over the limits of inappropriate transport speeds, etc.; or by placing these ejectors, in order to create a new "saw-toothed" flow axis with a flow pitch line with slopes between 0.1%o and2%o; the axis contains slopes and ramps, endowed with ejectors, so that it is possible to realize some sewage networks with reduced placing depths (1.5 í 5 m) on a high length and always sufficient to the extension necessary, especially on horizontal lands and where the level difference between the free surface of the water from the natural emissary (river, lake, etc.) and the collection depth is reduced, so that it is impossible to set in function a classical sewage installation with gravity flow, because of the gentle slope that blocks it and it is also impossible its replacement with a sewage installation through pumping, which cannot collect through gravity flow downstream the pump.

In the sewage installation with ejectors according to the invention, it is allowed that, through the hearths with ramp - slope (with slope restoring), configured with lifting

ejectors (ramp) - and lowering ejectors (slope), in order to be transferred impulses for speed increasing - the equivalent of a pump, but at low pressures - and to maintain the capacity to collect from other networks, through gravity flow at atmospheric pressure until the purifying-treatment station and farther to the emissary.

The gravity flow of black water on a network with "saw-toothed" longitudinal profile with slope restoring hearths with ejectors is in 100% buried system; it has the lines of hydraulic current as some spread waves, co-sinusoidal and undamped, with forced oscillations near the ejectors (during their functioning), and when the ejectors do not work, the flow is free, according to the median slope, contained between O.l%o and 2%o, which allow the flowing of the liquid phase and temporary depositions, but placed only in the near upstream of each hearth with ejectors, from where there will be pulled along at the next start of the ejectors. In this way, there is realized a combination between gravity flow with very gentle slopes and a flow under pumping pressure (through ejectors) with low dynamic pressures. In this way there is also solved, it the same time, the transport on long distances but also the absorption of gravity flows from other sources and collecting networks. The invention presents the following advantages

• the maintenance washing is made through dedicated equipments (ejectors), mounted on the conducts/channels of a sewage installation with gravity flow, with or without free surface;

• the maintenance washing is made periodically or programmed, without the introduction from the exterior through visiting hearths, of some technical means for intervention, which means to avoid the occupation of the practicable and the reduction of the maintenance expenses and implicitly, of the costs;

• the pulling along of the depositions and particles with high density (sand, gravel, etc.), which cannot be pulled along by the used water with reduced flow speed;

• the maintenance washing is made with contribution of technological water under pressure, from the purifying - treatment station, through an under-ground supplying pipe, mounted in parallel with the conducts/channels and it has a centralized control;

• the maintenance washing is also made with mobile water sources and mobile pumping sources, through mini-hearths of coupling, for alignments with reduced lengths and sporadic water discharges

• it creates the premises for the automation of the maintenance washing operation;

• the washing and cleaning of the conducts/channels is made independently of the exterior meteorological conditions;

• it allows the increasing of transportation speeds through conducts/channel, in the case of an alignment with gentle slope, in order to avoid depositions and clogging, in the period with reduced or sporadic water discharge;

• it allows the increasing of transportation speeds through conducts/channels, in the situations with peak of water discharge, for a constructive, transversal section of the conduct/channel, smaller than the one that is necessary;

• it allows the creation of a safety circuit in parallel with a sewage circuit, in order to absorb the excess of used water discharge or/and meteoric waters;

• it allows the realization of the extension in upstream of a existent sewage installations, which are at the limit of ensuring the minimal flow-slope;

• it allows the realization of some sewage installations with longitudinal profile of the "saw-toothed" alignment in slopes and ramps that have gravity flow, without free surface (buried regimen), on long distances and with medium flow-slopes contained between 0.1%o and 0.5%o, through pairs of lifting-descending ejectors, which configure hearths with slope restoration (saw-toothed) and flowing in inversed siphon;

• it allows the realization of some sewage installations that have gravity flow, placed at reduced depths (1.5í4m), imposed by the reduction of thickness of the soil layer consisting in non-permeable rocks from above a subsoil with permeable rocks and with infiltrations;

• it allows the restoration, the improvement of some existing installations, in themselves known, through the equipment with ejectors, doubling the circuits, etc.;

• it allows the access for all the cleaning means, in themselves known, presently used for cleaning the conducts/channels/hearths, in the case of heavy clogging with big bodies, or through the disrespecting of the quality of evacuated used waters (example: water with cement dust, vegetal remains from grapes, etc.);

• it allows the stopping of liquid fuels only at the network with "saw-toothed" profile, near the hearths with "slope-restoring", if the ejectors are stopped;

• it allows a substantial increasing of the speeds and implicitly of the evacuation water discharges, especially for the excess meteoric waters at the installations of separating type.

There are next given a few examples of the inventions realization, also related to the fig. 1, 2, 34, which represents:

• fig.1 - a scheme of a sewage installation, in itself known, equipped with tubular ejectors

• fig.2 - a view in perspective, with longitudinal section of a tubular ejector with closed contour

• fig.3 - a cross-section through a tubular ejector with opened contour

• fig.4 - a longitudinal section of a tubular ejector with opened contour, placed in the interior of a conduct

• fig.5 - a view in perspective of a tubular ejector with opened contour

• fig.6 - a cross-section through a tubular opened ejector placed in a conduct with a semi-elliptical bell contour

• fig.7 ~ a representation in exploded perspective of a opened tubular ejector with semi-elliptical bell contour

• fig.8 - a cross-section through a tubular ejector with closed contour, for egg- shaped conducts with bench and ditch

• fig.9 - a view in perspective, with breakages and sections, of a tubular ejector with closed contour for egg-shaped conducts, with bench and ditch

• fig.10 - a cross-section through a tubular ejector with opened contour, placed at the hydraulic apron of a coupling/passing through hearth

• fig.11 - a view in perspective, with partial breakages, of a tubular ejector with opened contour, for placement at the hydraulic apron of a coupling/passing through hearth

• fig.12 - a longitudinal section through a coupling/passing through hearth with a short tubular ejector, mounted from the hearth, in the upstream head of a conduct

• fig.13 - a cross-section through a short tubular ejector

• fig.14 - a view in perspective, with partial breakages and sections, of a tubular, rectangular, opened ejector, for rectangular conducts/channels

• fig.15 - a view in perspective, with partial breakage, of an assembling with flare between a tubular, rectangular, opened ejector and rectangular conducts/channels

• fig.16 - a view in perspective of a tubular, rectangular, opened ejector, mounted within the rectangular conducts/channels of box type

• fig.17 - a view in perspective of a tubular, rectangular, opened ejector, with multiple jets for rectangular conducts/channels

• fig.18 - a representation with partial longitudinal section through a mechanical assembly with in series jets

• fig.19 — a partial view in perspective and with partial breakage of an assembling with flare between a tubular, rectangular, opened ejector, with multiple jets and rectangular conducts/channels of box type

• fig.20 - a view in perspective of a tubular, rectangular, opened ejector, with multiple jets, mounted within rectangular conducts/channels of box type

• fig.21 — a view in perspective of the placement in alignment of some tubular, trapezoidal, opened ejectors, on a trapezoidal, opened channel

• fig.22 - a view in perspective and partial sections through a trapezoidal, tubular, opened ejector and a trapezoidal, opened channel

• fig.23 - a view and a partial, longitudinal section of an ejector with two tubular jets, mounted from a coupling/passing through hearth, in the downstream head of a conduct

• fig.24 - a longitudinal section and partial views through a coupling/passing through hearth equipped with ejectors mounted from the interior of a coupling/passing through hearth in the downstream and upstream heads of the conducts

• fig.25 - a scheme of a sewage installation, in itself known, over which it is mounted a network of conducts with ejectors with gentler slope through the same coupling/passing through hearths

• fig.26 - a representation in perspective, with cross-section and partial views of a coupling /passing through hearth used in common by two networks of superposed conducts, from which the one placed on top is with ejectors

• fig.27 - an axonometric representation of an alignment of conducts equipped with tubular ejectors between the coupling/ passing through hearths and coupling mini-hearths with mobile aggregates for supplying with under-pressure technological water

• fig.28 — a longitudinal section through a conduct equipped at the interior with tubular ejectors

• fig.29 — a scheme of a sewage installation, with "saw-toothed" longitudinal profile, with conducts in slopes and couplings/passing through hearths in slopes, with ejectors at the head of the conducts

• fig.30 — a schematic representation of a conduct equipped with ejectors and buried flow in slope, between two consecutive coupling/passing through hearths

• fig.31 — a scheme of a sewage installation with longitudinal profile, with slopes and ramps between coupling/passing through hearths, with conducts equipped at the heads with ejectors, with buried flow

• fig.32 - a longitudinal section and partial views of a hearth with slope restoration and conducts equipped with ejectors, with buried flow

• fig.33 — a longitudinal section, partial views and local transversal sections, through a double sewage installation, between two consecutive hearths of a installation, in itself known, and common at a "saw-toothed" installation with ejectors, with conducts in slopes and ramps and hearths with slope restoring (network with inversed siphons)

• fig.34 - a longitudinal section through a sewage installation of sub-passage, with conducts in slope and ramp with ejectors and coupling/passing through hearths with slope restoring.

In the first example of the invention's realization also related to fig.l and 2, it is presented a simple sewage installation of used waters (sewage, black, etc.) that has gravity flow with free surface through conducts and hearths, of unitary type, equipped with ejectors with tubular jet of under pressure technological water, for maintenance washing, depositions cleanings or increasing the medium transport speed of the used waters and which is mainly formed of some conducts 1 placed in the soil, at a convenient depth and in slope between some hearths 2 for absorption and collection of

W

used waters from the clients (punctual sources of used waters), a purifying-treatment station 3 and a overflow tube 4 of contact with a natural emissary (river, lake, etc.) or artificial emissary, for evacuation. The slope angle of the soil is "α". The geometrical axes of the conducts 1 form the axis of alignment and of flowing or the placement routing and flow routing and it has in longitudinal profile an angle "αj" of the flow slope, compared to a horizontal plan; this routing starts with the first hearth 2 and ends into the emissary; on the routing there can be also hydraulically coupled some openings of meteoric waters 5, some openings of snow 6 and a pumping station 7; the medium flow slope in the installation is generally contained between 2%o and 4%o. At the sewage installations of separating type, the openings of meteoric waters and snow have a separate circuit for collection and transportation to the purifying-treatment station, generally with conducts of tubular shape.

On the conducts 1 there are placed some ejectors 8, generally of tubular shape, which communicate with the hearths 2 and then until the emissary through the purifying - treatment station 3 and through the overflow tube 4. The ejectors S are supplied with under-pressure technological water coming from the purifying-treatment station 3 or from the emissary, with the help of some coupling pipes 9 and a pipe 10 from the pumping station 7.

The ejector 8 is mainly constituted of an interior, tubular body 11 and an exterior, tubular body 12, assembled between each other at an end and profiled in such a way that they define at the interior a pressure room "a" continued with a cleft "b" where a water jet "c" is formed; the water jet "c" generally has tubular shape; the pressure room "a" is supplied with technological water pumped through an exterior nozzle 13, generally mounted tangential to the exterior tubular body 12; within the cleft "b" there are found some radial ribs 14, fixed on the interior tubular body 11 or on the exterior tubular body 12 and have the role of ensuring a constant thickness of the cleft "b"; the technological water flow from the pressure room "a" towards the cleft "b" is generally in the same sense with the flow of the used waters through the tubular ejector 8. The interior tubular body 11 and the exterior tubular body 12 are realized with flare- profiles with fitting for tight assembling at the conduct 1; for stiffening and mechanical protection, the exterior tubular body 12 is endowed with an exterior coat 14, a mandrel of end 15 and a filling mass 16 (for example: polymers, cement, etc.). On the interior tubular body 11, on the wall common with the annular pressure room "a" there are radially practiced some orifices "d", of small dimensions, which have the

role of allowing the injection of technological water in the transportation interior of the ejector 8, in order to fluidize deposition masses that took place in the non-working period of the ejector 8; on the exterior surface of the ejector 8 it can be applied a casing

17 of thin plate of stainless steel or titanium, with the purpose of increasing the protection against the gnawers, but also of increasing the mechanical resistance near the flare-profiles.

The ejectors 8 is made of various materials, such as: stiff plastic materials (p.v.c, etc.), stainless steels, bronzes, composite materials, ceramics, etc.; the realization of the ejector can be made by using only one type of material or by combined utilization of more materials.

The ejector 8 is a hydraulic device, which produces a tubular jet of water at reduced water discharges (0.5í2m ³ /h), under the shape some thin nappes with medium speeds contained between 20í50 m/s, which touches the tubular wall, exterior to the jet, and partially expands towards interior, situation in which it produces a slight depression in upstream and an increasing of the traction and an acceleration of the fluids through the interior of the entire ejector, and especially in its downstream.

The interior diameters of the conducts 1 for the used water flow are gradually chosen, increasing and proportionally to the flow length from upstream to downstream, and the diameters of the pipe 10 of supplying with technological water, for supplying the ejectors 8, are gradually chosen, decreasing and proportionally to the routing length from downstream to upstream; the conducts 1 are generally made of plastic material

(p.v.c, reinforced polymers with glass fibres) but they can also be made of other materials (cement, reinforced concrete, ceramics, etc.).

The ejectors 8 are made at various diametrical size in the flare area, in order to make possible their assembly with the conducts 1 at various diameters .

The minimum interior diameters of an ejector 8 are close, as dimensions, to the interior diameter of flowing through the conducts 1, so that it would not be an obstacle at the free flow of the used waters in the resting period of the ejectors 8.

The ejectors 8 functions discontinuously, approximately 10í30 minutes in rush hours and are started respecting a schedule, by manual or automatic control and centralized at the technological water pumping station 7.

The ejectors 8 get in function consecutively at the maximum regimen, from downstream, towards upstream of the sewage installation, and then there are realized a stationary flow and a leveling of the flow on the entire installation, either for the

washing - cleaning operation or for the increasing of the water discharge of evacuated used waters; the washing-cleaning operations can be executed in the hours with reduced water discharges of the sewage installation.

The ejectors 8 are used both for a sewage installation of unitary type and of separating type, for each of the water types and collection and transportation routing.

The water discharge of an ejector 8 is limited by its dimensions, and the water discharge of the jet "c" is limited by the dimensions of the cleft "b", by the pressure and water discharge of supplying with technological water.

A constructive regulation within these limits is hydraulically made through the couplings 9; generally, the water discharge of the jet of an ejector 8, placed downstream of a conduct 1 (at the entering into the hearth 2) is smaller than the one of an ejector 8 placed upstream of a conduct 1 (at the getting-out from the hearth 2).

In the second example of the invention's realization, also related to fig. 1, 2, 3, 4, and

5, it is presented a simple sewage installation of used water that has gravity flow with free surface (level) through conducts and hearths, of unitary type, equipped with ejectors with semi-tubular jet of under pressure technological water, for maintenance washing, depositions cleanings or for increasing the medium transportation speeds of used waters, in the conditions when the collection conducts 1 have diameters contained between 500mm í 1200mm. The distances between the alignment hearths 2 are contained between 100m í 250m, and the flow-slope is gentle and contained in average between 0.5%o í 2%o; the conducts 1 can have circular rounded contour, or egg-shaped contour.

For a conduct 1 with a circular rounded contour, the ejector 8 has a tubular shape with incomplete contour, so that, at the inferior part of the conduct 1, there is no obstacle made by the ejector, which would impede the used water flow.

The ejector 8 is constituted of the interior tubular body 11 and the exterior tubular body

12, assembled together and profiled in such way that it would define the pressure room

"a", continued with two clefts "b" disposed laterally and would constitute a tubular assembly on an arc of approximately 270°.

The jets "c" are produced by the clefts "b" by supplying the pressure room "a" with under pressure technological water.

Each front part of the tubular bodies 11 and 12 closes with a cap 18, without impeding the formation of the clefts "b" at the downstream part of the ejector 8; on each cap 18, it is mounted the nozzle 13, in longitudinal position.

The ribs 14 ensure the uniform thickness of the jets "c", a stiff mechanical connection between the tubular bodies 11 and 12 and a pre-conduction of the lines of current of the under-pressure technological waters from the pressure room "a" to the clefts "b". Compared to the plan that contains the upstream front part of the ejector 8, the downstream front part that contains the clefts "b" and a part of the cap 18 is inclined so that the short edges of the ejector 8 are shorter with an interior radius length of the conduct 1 compared to the maximum longitudinal dimension of the exterior tubular body 12, with the purpose of ensuring a quick extraction of mass deposed near the clefts "b" and especially in the cases when the ejector 8 is mounted downstream the conduct 1 and very close, as mounting position, to the wall of the hearth 2. These types of ejectors are recommended to be supplementary mounted also in the interior of the conducts 1; this thing is possible through the fact that they allow by their reduced length the introduction through the hearths 2 into the conducts 1 and the coupling in series for supplying with under pressure technological water; the coupling in series is realized through the interior of the conducts 1 and does not necessitate other installation works for the pipe 10 with under pressure technological water. For the conducts 1 with egg-shaped contour, the ejector 8 will be realized with the same egg-shaped contour.

In the third example of the invention's realization, also related to fig.l, 6 and 7, it is presented a simple sewage installation of used water (sewage, black, industrial waters, etc.) that has gravity flow with free surface (level) through conducts (channels) and hearths, of unitary type, equipped with ejectors with semi-tubular jet of under pressure technological water, for maintenance washing, depositions cleanings or the increasing of the medium transport speeds of used waters, in the conditions when the collecting conducts 1 have the cross-section in the shape of a semi-elliptical bell and have the maximum dimension contained between 600 mmí3 000 mm; the distances between the alignment hearths 2 are between 10Oí250m, and the flow slope is gentle and contained in average between O.5%o - 2%o; the conducts 1 of standardized and semi-manufactured construction are formed of two lateral walls and a apron-support made of concrete or

reinforced concrete, which are assembled and tightened on the ground into the dug channel.

The ejector 8 of opened tubular construction is constituted of the interior tubular body

11, the exterior tubular body 12 and a central body 19, assembled between each other and profiled in such way that to define between them a pressure antechamber "e", the pressure room "a" continued with two clefts "b" and to constitute a semi-elliptical, opened, tubular assembly in a bell-shape on an arc of approximately 180°; the jets "c" are produced by the clefts "b" by supplying the pressure antechamber "e" and the pressure room "a" with under-pressure technological water; the clefts "b" and the jets

"c", in the shape of semi-elliptical arcs, are realized on the edge of the lateral parts that have the same shape.

The front and contour part of the tubular bodies 11 and 12 and also of the central body

19 closes with more caps 18, without impeding the formation of the clefts "b" at the downstream part of the ejector 8.

The ribs 14 ensure the uniform thickness of the jets "c" near the clefts "b", a stiff mechanical connection between the tubular bodies 11 and 12 and a pre-leading of the lines of current of the under-pressure technological water from the pressure room "a" to the clefts "b".

The assembly of the tubular bodies 11 and 12 is generally of duplex construction (two pieces) and assembles at the mounting on the installation, together with central body 19.

The central body 19 configures in the interior a pressure antechamber "e" endowed with some orifices "f that communicates through the orifices "d" with the pressure room

"a".

The length of the central body 19 is the same to the length of the ejector 8 and has in cross-section a semi-elliptical, egg-shaped profile, resembling to the one of the assembly of the tubular bodies 11 and 12 and of the semi-elliptical walls of the conducts

1, semi-manufactured of concrete/reinforced concrete.

The central body 19 has a supplying opening 20 that communicates with the coupling pipe 9 or directly with the supplying pipe 10 with under-pressure technological water; the technological water used can also be the industrial water used and filtered, water that is admitted in the same used water purifying-treatment station.

The assembling of tubular bodies 11, 12 and 19 is made through nut bolts or tubular rivets near some holding orifices "g" practiced on the bodies 11, 12 and 19.

The ejectors 8 are mounted in the same time with the main sewage conduct itself, which is assembled of semi-manufactured on the concrete/reinforced concrete apron of the actual sewage routing.

The ejectors 8 have a small cress-section and do not significantly influence the reduction of the flow cross-section and do not represents any obstacle in the proximity flow-area on the apron; the propelling tightening on the apron support is made with the same materials and technology as for the prefabricated elements of the conduct, for example: the cement mortar caulked with bituminous mastic or more recently with foils and layers of polyurethane adhesives or bi-component, polymerizing, epoxy resin, etc.

The forth example of the invention's realization, also related to fig. 1, 2, 8 and 9 presents a simple sewage installation of used water (sewage, black, industrial waters, etc.) that has gravity flow with free surface through conducts (channels) and hearths, of unitary type equipped with ejectors with profiled jet of under pressure technological water, for maintenance washing, deposition cleaning or increasing the medium transport speeds, washing and ventilation before making visits through the interior of the technical staff, in the conditions when the collecting conducts 1 are in cross-section in egg-shaped profile with bench and ditch and which have the maximal dimensions contained between 1500mmí3000mm, the distances between the alignment hearths 2 are between 250mí500m; the flow-slope is contained between 0.5%o and 2%o; the conducts 1 are made of concrete/reinforced concrete, or entirely or partially constructed of brick masonry.

The ejector 8 is constituted of the interior tubular body 11, the exterior tubular body 12, assembled together and profiled in such way that to define the pressure room "a" continued with two clefts "b" and to constitute a tubular assembly with short length and a profile resembling to the one of the interior of the conduct/channel 1. One of the clefts "b" is parallel to the bench (the horizontal part). The other cleft "b" has the contour of the ditch and it is elongated in its lower part.

The front part of the tubular bodies 11 and 12 encloses with the caps 18, generally in conical shape, without impeding the formation of the clefts "b" in the downstream part of the ejector 8.

The ribs 14 ensure the uniform thickness of the jets "c" near the clefts "b" and a pre- leading of the lines of current of under pressure technological water, from the pressure room "a" to the clefts "b".

The jets "c" are initiated a little over the low walls of the conduct 1 and produce entrainments, aspirations and transfer of mass impulses on the main flow-routing of the heavy particles from the ditch and from near the bench.

For the mechanical stiffening of the body 11 compared to the body 12 there are used a annular rib 21 and an axial rib 22, both of them endowed with the orifices "P in order to allow the supplying, with under pressure technological water, of the pressure room

"a".

The pressure room "a" is supplied through some nozzles 13 that can be connected to the coupling pipe 9, or even the supplying pipe 10; the supplying pipe 10 with under pressure technological water can be mounted either in the exterior of the conduct 1, or through its interior, also through the interior of the ejectors 8.

The ejector 8 is endowed with some rollers 23 in order to be moved and positioned in the interior of the conduct 1.

The maximum length of the ejector 8 is in the area of the clefts "b", the rest of the body being significantly reduced as length, for the situation of mounting it in a conduct 1 of an existent installation, and its introduction is made through an alignment hearth; after the positioning, the ejector 8 is mechanically fixed on the interior walls of the conduct 1, through known mechanical means (fixed thresholds, safety rings, etc.). Constructively, the entire ejector 8 can be built of two pieces and hermetically assembled, in the middle, in the area of the annular rib 21.

The fifth example of the invention's realization, also related to fig. 1, 2, 5, 10 and 11 presents a simple sewage installation of used water that has gravity flow with free surface (level) through conducts (channels) and hearths, of unitary or separating type, equipped with ejectors placed into the hearth, with profiled jet of under-pressure technological water, for maintenance washing, depositions cleaning, quick emptying of the hearths and increasing the medium transport speeds, in the conditions when the ejectors are mounted within the hearth, in order to increase the performances of an installation that was mounted without ejectors; the conducts 1 are usually tubular and have diameters contained between lOOmmíl 000mm.

The ejector 8 is transformed from the tubular version with circular or egg-shaped cleft into a version in which the cleft "b" follows the low half of the interior profile of the conduct 1, and the assembly of the interior body 11, exterior body 12 and the caps 18 follows the hydraulic contour of flowing through the opened channel of the hearth 2,

which is for coupling/passing through or visiting. The pressure room "a" is disposed on each side, compared to the longitudinal flow axis through the hearth 2, the ribs are practically placed between two concentric walls and have the role to ensure the constant thickness of the jet "c", to ensure the mechanical stiffening between the interior body

11 and the exterior body 12 and to ensure a flow leveling of the under-pressure technological water from the pressure room "a" towards the cleft "b".

One of the caps 18 has plane surfaces necessary to the placement of the ejector 8 and its catching on the apron-plate of the hearth 2. The pressure room "a" is supplied with under-pressure technological water through the nozzles 13.

Through the designed configuration, the ejector assembly has two inflexion axes, with changes of concavity (convex -concave - convex).

The ejector 8 has a length bigger than the longitudinal dimension between the parallel walls of the hearth 2, so that the chute (channel) shape of the ejector assembly would be propelled on the interior of the conduct 1.

At this application, for a hearth 2 is mounted only one ejector 8 of this configuration, which operates upstream of a conduct 1, which gets out of the hearth 2.

In order to reduce the hydraulic resistance at the used water flowing through the ejector

8, one of the caps 18 is mounted inclined down, upstream the ejector, which coincides with the downstream of another conduct 1 that evacuates into the hearth 2.

The ejector 8 is generally made of plastic materials of p.v.c. type and is easy to mount and supply with under-pressure technological water, through coupling pipes 9 and the supplying pipe 10; the pumping can be made either from a pumping station 7, or from a mobile source, endowed with a motor-pump.

The sixth example of the invention's realization, also related to fig. 1, 2, 12 and 13 represents a known sewage installation with conducts and hearths, to which ejectors are needed in order to increase the evacuation water discharges, in certain periods of time with warheads, situation that produces depositions into the hearth, more than the deposit, constructive admitted on a installation; the ejector is only used for the get out of the hearth, on the upstream of a conduct and it is recommended to be used in small- seized hearths, found on an existent installation, or for the direct construction of a hearth with ejector at the installations to be built.

The ejector 8 is mounted upstream the conduct 1 with circular or egg-shaped contour and is supplied with under-pressure technological water through the coupling 9 from a supplying pipe 10.

The ejector 8 is formed of the interior body 11 and the exterior body 12 that has the shape of a built-up barrel; between the interior body 11 and the exterior body 12 it is formed the pressure room "a" that communicates with the annular cleft "b" formed between the body 11 and the conduct 1; the exterior body 12 is fixed on the wall of the hearth 2, and the interior body 11 is fixed on the exterior body 12; the fixing is made with screws; between the interior body 11 and the exterior body 12 is found a tightening garniture 24, and between the exterior body 12 and the common heads of the conduct 1 and the passing-through flare 25 there is a tightening and centering garniture 26.

The interior body 11 is generally made in duplex construction.

The coupling 9 is mounted tangentially on the exterior body 12 endowed with the nozzle 13.

The ribs 14 fixed on the interior body 11 in the cleft "b" area center on the interior surface of the conduct 1.

In the hearth 2 the coupling of the conducts 1 is made at the apron with a supplementary apron-plate 27, fixed in the hearth; the propelling and tightening of the ejector S on the apron-plate 27 is made through some garnitures 28 and 29.

The apron-plate 27 has the role of avoiding deposits of depositions in the hearth 2, hearth elongated down in order to allow the mounting of the ejector 8; the apron-plate

27 of concrete or reinforced concrete is formed of some segments 27 _a , 27b and 27 _C that can be demounted in order to allow the replacement of the ejector 8; the segment 27 _b is fixed with screws (clamp) and nuts on the poured apron of the hearth 2, and for protecting the assembling it is endowed with a tightening cap 30.

The ejector 8 is generally made of plastic materials (p.v.c, etc.) and can be plated with the casing 17 of stainless steel on the tubular surfaces of interior and contact with the used waters of the interior body 11.

The seventh example of the invention's realization also related to fig. 1, 7, 14,.... and 20 presents a sewage installation that has gravity flow with free surface (level) or without free surface (buried flow) of unitary or separating type, with conducts/channels 1 with rectangular profile of concrete/reinforced concrete with square or rectangular section, with dimensions contained between 1500mm í 3500mm and hearths 2, the

distances between hearths being contained between 250í1000m with uniform flow- slopes, usually contained between 0.5%o í 2%o or with medium flow slopes with the same values and in which, on some segments of the routing, the slope is zero or in counter-slope at low values contained between 0. l%o - 0.25% ₀ .

The installation is equipped with the ejectors 8 generally disposed on the length between the hearths 2, at one step of 150í250m.

The ejectors 8 for an installation at which the flow is with free surface and has a filling degree of 70 - 80%, are formed of the interior body 11 and the exterior body 12, with semi-tubular rectangular shapes, of caisson-type construction, between which the pressure room "a" is defined; the ejector 8 has the general shape of a rectangular channel with opened profile, at the down-side of the lateral walls, the common part of the interior body 11 and the exterior body 12 has a prism - shape with tubular interior and communicates with the pressure-room "a" and into which there are introduced two concentric tubes, an exterior tube 31 and an interior tube 32, closed at one end and opened at the other end, which form the cleft "b".

The exterior tube 31 is endowed with the orifices "P for the passing of the underpressure technological water from the pressure room "a" into the volume between the concentric tubes 31 and 32 and farther into the clefts "b" that produce the jets "c" of tubular-shape.

The exterior tube 31 hermetically centers at the contact walls.

On the lateral walls and towards interior, two lateral clefts "b" that produce jets "c" of plane shape, are also formed.

The supplying of the ejector 8 with technological under-pressure water is made through the nozzle 13, which is centrally placed on the external, plane face of the exterior body 12.

The ribs 14 ensure a convenient distribution of the technological water from the room "a" towards the clefts "b" and mechanical stiffening between the interior body 11 and the exterior body 12.

The ejector 8 is technologically constructed of more semi-manufactured bodies of reinforced concrete, hermetically assembled with mortars and adhesives; the exterior dimensions of the ejector 8 are smaller than the interior dimensions of the conducts 1 with rectangular profile; their mounting is made through the introduction from the upside into boxes, after that there are mounted the caps of the box, endowed with the passing through-flare 25.

Another way of assembling on the conducts 1 with rectangular profile is by mounting in series, in this case the exterior dimensions are the same at the ejector 8 and the conducts 1; the coupling and tightening is made through some passing through-flares 33 with square or rectangular closed profile.

The ejector 8 for an installation at which the gravity flow through conducts is without free surface (buried flow) of unitary or separating type, with conducts 1 of box-type of concrete/reinforced concrete with square or rectangular section of big dimensions, is supplementary endowed with a central-axial body 34, mounted under the interior body 11 through a pillar 35.

Within the central body 34 it is introduced a tube 36 profiled at the ends in such way that it would form two clefts "b" constituted upstream and downstream the tube 36, so that the jets "c" formed by the clefts "b" are in the used waters flowing direction; the ribs 14 center and fix the tube 36 compared to the central-axial body 34. Between the tube 36 and the central - axial 34 enters the under-pressure technological water from the room "a" through some channels "h" that pass through the pillar 35 and orifices "f" practiced in the central body 34 and in the interior body 11. The central body 34 is endowed upstream with a convergent nozzle 37 that ensure the formation of the cleft "b" placed upstream and the concentration of the lines of current at flowing through the axial transport volume of the interior body 36. The assembly formed of the central-axial body 34, the interior tube 36 and the convergent nozzle 37 is practically axially mounted, in order to accelerate and ejects the used waters from the middle of the flux of used waters that occupies the entire flow volume.

The assembling of the ejectors 8 with central - axial body 34 from above on the conducts 1 of box-type is made in the same way as at the ejectors 8 without the central- axial body presented in this example of the invention's realization.

Another example of the invention's realization - the eighth example - also related to fig. 21 and 22 refers to a sewage installation, of unitary or separating type, which has gravity flow, with free surface (level), with opened profile of the channels and equipped with ejectors; the opened channel, usually made of concrete, reinforced concrete or walled-up rocks, has various profiles: deltoid, rectangular, combined from the deltoid and rectangular profiles, semicircular, parabolic and trapezoidal; next it is presented the channel with the most used profile, namely the channel 1 with trapezoidal profile.

The channel 1 is equipped with one or more ejectors 8 disposed at certain distances between them and which have the role of washing and cleaning the channel, but also of increasing the medium flow speed and flow acceleration in the installations in which the filling degree is higher than 60% and with tendencies of quick increasing, especially due to the contribution of meteoric waters.

The ejector S of opened trapezoidal shape is formed of the interior bodies 11 and exterior bodies 12 assembled in caisson-type construction, closed at the ends with the caps 18, from which some are endowed with the clefts "b" for the production of the jets

"c" of under-pressure technological water and with the orifices "d"of small dimensions, for the transversal injection of under-pressure technological water in small quantities under the ejector and upstream the clefts "b" for cleaning and fluidizing the deposed materials, but also for emptying the residual water from the ejector during the winter.

The jets "c" are plane, have a significant width and they are produced at a small distance to the walls of the channel 1; the flow of the jets "c" is approximately parallel to the walls of the channel 1 and have parabolic heading.

Between the interior bodies 11 and the exterior bodies 12 there are formed a few pressure rooms "a" that communicate between them through the orifices "f '.

The supplying with under-pressure technological water is made through the nozzles 13

(in number of four pieces) mounted on each of the lateral parts and at both of the heads of the ejector 8.

The nozzles 13 are coupled through the coupling pipes 9 to the pipes 10, which receive under-pressure technological water from one or more pumping stations 7, function of the total length of the channels 1; this length can be contained in average between

1000m í 15 000m.

The opened channels with trapezoidal section can have various dimensions as height and middle line of the trapeze; in this way the height can be contained between

0.20í0.50m and with the middle line contained between 0.25m í 0.75m for small channels, and for the big channels the medium heights can be contained between

0.75 í 2.00 m and the middle line contained in average between 0.75 í 3.00 m.

The ejector 8 is propelled and fixed on the channel 1.

For all the types of opened profiles, the general contour of the ejector 8 resembles to these.

The ejector 8 can be realized as assembly from separate parts that are fixed one to another; the ejector 8 can be entirely made of materials like: reinforced concrete, plastic materials (p.v.α, etc.), composite materials (carbon fibre with polymers, etc). The channel 1 is with pitching (realization of walls and walled-up streambed) or without pitching; the channel without pitching is practiced on cohesive soil and becoming overgrown with grass flanks must be concreted with cyclopean concrete near the placement area of the ejector 8, as well as upstream the ejector 8 on a length of approximately 3m, and downstream on a length of minimum 10m on the entire trapezoidal profile and in addition, in the area from near the clefts "b" the oblique walls will be smoothly plastered with cement and fine sand on a length of minimum 5m.

The ninth example of the invention's realization, also related to fig. 1, 2 and 23 presents a sewage installation of unitary or separating type, with gravity flow with free surface through conducts and equipped with ejectors near the cleaning or coupling hearths, etc, for the situation when the downstream ejectors of the conducts 1 are mounted through the hearth 2 in the downstream end of the conduct 1 and through its interior.

Generally, these ejectors are applied on the existent sewage installations that have reached at the maximum limit of capacity and create depositions and blockings as well as a reduced leakage flow speed in the hearth.

Downstream each conduct 1 is placed an ejector 8, which is introduced in the interior of the conduct 1 through the hearth 2; the length of the ejector 8 is limited by the interior dimensions of the hearth 2.

The ejector 8 is formed of four interior bodies 11 of tubular - cylindrical and conical shape and two exterior bodies 12; these bodies are assembled so that they would form in the interior four pressure rooms "a", with the purpose of allowing the supplying with under-pressure water through the nozzle 13 and of forming two jets "c" that are annular and concentric to the conduct 1 through the clefts "b", axially placed at different distances from the downstream end of the ejector 8; one of the jets "c" namely the one formed in the middle of the ejector 8 has the same sense with the used water flow through the conduct 1, produces ejection and acceleration and consumes approximately 75% of the quantity of under-pressure water with which is supplied the ejector 8, and the other jet "c" has opposite sense compared to the used water flow through the conduct 1 and is formed at the upstream head of the ejector 8, in the neighborhood of

the interior wall of the conduct 1; the role of this jet "c" is to quickly dislocate the materials deposed in the upstream of the ejector 8.

The ejector 8 has a demountable construction in order to be placed as its big components are introduced within the conduct 1; the contour of the cross-section of the ejector 8 is similar with the contour of the cross-section of the conduct 1.

The tenth example of the invention's realization also related to fig. 1, 12, 13, 23 and 24, as well as to the sixth and the ninth example of the invention's realization, presents a sewage installation of unitary or separating type with gravity flow with free surface through the conducts and equipped with the ejectors near the cleaning and coupling hearths, etc., for the situation of mounting the ejectors on an existing installation, through hearths and in the interior of the conducts, with the purpose of restoring the capacity of working of an existing installation, but also for installations that will be built and that , in perspective, will be equipped with ejectors; generally, these installations are endowed with conducts made of concrete with various profiles of the contour of the cross-section of the conducts.

The installation is formed of the conducts 1 and the hearths 2 through which the ejectors 8 are introduced through the conducts 1; in this way in the upstream of a conduct 1 the ejectors presented in fig. 12 and 13 are mounted, and downstream of a conduct 1 the ejectors presented in fig.23 are mounted. In the hearths is mounted the apron-plate 27 of demountable construction and formed of the segments 27 _a , 27b and 27 _C that allow the lifting of the hydraulic apron in the hearth 2 for a flow without deposit in the hearth. The supplying with under-pressure technological water is made through the couplings 9 and the pipe 10 from the pumping station 7.

The eleventh example of the invention's realization, also related to fig. 1, 2, 25 and 26 presents a double installation (with, two circuits) of sewage with gravity flow with free surface through conducts, for increasing the transport capacity of an existent sewage installation that has two geometrical axes in longitudinal profile, each axis has a slope of its own "αi" (angle compared to the horizontal) and represents two flow alignments with different slopes in longitudinal profile; an alignment of the conducts 1 placed between the hearths 2 at their hydraulic apron for a classical sewage installation, in itself known, generally of unitary type (everything at the channel) with coupling hearths and a supplementary alignment of the conducts 1 placed higher, between the hearths 2

at a tubular apron 38 endowed with an oscillating cap 39, demountable fixed between the ejectors 8 mounted in the upstream and downstream heads of the conducts 1 of the sewage installation that functions in parallel at a slope "αi" gentler than the one of the sewage installation in itself known, placed lower; the lateral couplings from the sources of used sewage water are made directly to the conducts 1 equipped with the ejectors 8. The hearths 2, generally coupling or visiting hearths, are endowed with the necessary cut-outs that allow the mounting of the ejectors 8 and the tubular apron 38; the tubular apron 38 is semicircular in its central part and is comparable to a chute; the tubular apron 38 is optionally endowed with an oscillating cap 39 of semi - tubular shape. The excess of used water of the sewage installation with ejectors is eliminated through the tubular apron 38 and is absorbed through the hearths 2 by the conducts 1 of the sewage installation - in itself known - placed lower at the hydraulic apron of the heaths 2.

The hearth 2 is built of two bodies with a median horizontal plan of separation near the ejectors 8 and is optionally endowed with a raster - spacer 40 made at different thickness in order to correct the total height of the hearth so that it would be at the same level with the practicable surface.

The hearth 2 can be made entirely or partially of various materials and with different technologies; the materials can be: concrete/stressed concrete, reinforced concrete, reinforced polyesters, ceramics, fired and glazed clay, poured basalt, composite materials, etc; the technologies can be: simple pouring into formworks, under-pressure pouring into matrix, centrifugal pouring, formation through processing, walled - up construction, etc.

As in the first example of the invention's realization, the ejectors 8 are periodically supplied with under-pressure technological water through the pipe 10 from the pumping station 7 through automatic or manual control.

This example of the invention's realization is useful for the situations of technical restoring by doubling in vertical plan or/and extension in upstream of the sewage installation found in exploitation, which does not corresponds to water discharges, and the total replacement of the conducts 1 with other conducts with higher diameters is complicated and expensive, and supplementary at which the number of clients - suppliers of used waters- increased, both on the alignment length, and upstream of the entire existent installation, and the ones to be coupled.

Another application of this example of the invention's realization is for the sewage installations of separating type with only one central ditch of diggings at mounting, which uses the alignment (circuit) with the ejectors 8 for meteoric waters, independent of the alignment (circuit) of used sewage waters placed lower; a particular case is the one when the meteoric waters are replaced by industrial waters.

In the case of the extensions in upstream of an existent sewage installation - extension realized through this example of the invention's realization - the utilization of a thermo- isolated conduct 1 on the alignment with ejectors allows a placement in depth at the limit of the permafrost thickness, or even at smaller depths, function of the conditions and punctual parameters of the installation and soil.

The installation is remarkably effective, for the case of overflowing and evacuation of used waters with flammable liquids on the alignment with ejectors, without contaminating the alignment with used sewage waters.

The twelfth example of the invention's realization also related to fig. 1, 2, 8, 9, 27 and

28 presents a part of the alignment of a sewage installation equipped with ejectors and with gravity flow with free flow-surface or without free flow-surface (flow in buried regimen) of unitary or separating type through conducts, contained between the hearths placed at long distances between them; the distances are between 50m í 500m.

The installation is equipped with more ejectors 8 placed in series with conducts 1 as in fig. 27 or placed in series within a conduct 1 with big length (100m -í- 500m) and big diameter (0.5m í 3.5m) — the case of the concrete conducts with bench and ditch - as in fig. 28, etc.

The ejectors 8 are generally meant for washing, cleaning and accelerating the flow of used waters in the situations with increased or much increased water discharges, in the situations of evacuating some used sewage or industrial waters with overloads of the suspensions with high dimensions or which must be quickly evacuated because of their toxicity and volatility.

The ejectors 8 can also be effectively used in the case when the sewage installation is only for meteoric waters, either for depositions cleaning or for flow acceleration.

In all the situations of use, the installation allows lateral couplings on the conducts 1 in the spaces between the ejectors 8.

The ejectors 8 are supplied with under-pressure technological water, either through a pipe 10 from the pumping station 7, or through some mini-hearths 41, which allow the

coupling with mobile aggregates for supplying with under-pressure technological waters (motor tank trucks, portable motor-pumps coupled to a hydrant or other close water source, etc.).

The operating of the ejectors 8 coupled with the mini-hearths 41 is made gradually and for short time (30í90 seconds) from the downstream area towards the upstream area of the sewage installation, for an effective cleaning and emptying; the cycle can be repeated in the case of cleaning heavy and adherent depositions and closes with a final washing produced from upstream to downstream.

In the case of the ejectors 8 placed within the conducts 1 with big diameter, the ejectors 8 are constructive adjusted from the clefts "b" in order for the ejectors 8 from the upstream area to supply a discharge of the jet "c" bigger than the one of the ejectors 8 from the downstream area of the installation; also, these ejectors can be consecutively supplied with under-pressure technological water through control from distance given to some electro-valves that belong to an installation of control or automation associated to the sewage installation and which is not part of the invention's object.

The thirteenth example of the invention's realization also related to fig 1, 2, 23 and 29 presents a sewage installation with gravity flow equipped with ejectors, of unitary or separating type, which has a flow without free surface through conducts (buried or semi-buried flow) and a flow with free surface in the hearths; it is a sewage installation that ensure the transportation of a medium discharge of used water on big lengths and at gentle slopes (reduced placement depths) for soils without slopes and with detrimental subsoil (reduced resistance to compression, permeable, non - cohesive, abundance of other installations, etc.) on a thickness of 5í10m.

The installation has a longitudinal profile called "saw-toothed", so that each conduct 1 has a slope angle "c^" of placement between some hearths 2 _a , and the general flow slope ("wave crest") on the entire installation has an angle "αi"; the angle formed of the land plan and the geodesic horizontal is the angle "α"; the geodesic horizontal of the place is perpendicular on the radius, from that place, of the globe. The relation between the angles α, αi and <*2 is this: α ₂ > Ct ₁ > α.

In every hearth 2 _a the downstream head of a conduct 1 is placed lower than the upstream head of the next conduct 1; the hearths 2 _a become hearths with slope restoration.

The couplings from the clients (punctual sources of used waters production) are admitted to be realized at the conducts 1 and in the hearths 2 _a .

On each upstream and downstream head of a conduct 1 is placed an ejector 8 that communicates directly to a hearth 2 _a .

The ejectors 8 are adjusted function of the cross-section contour of the conducts 1 and are supplied with under-pressure technological water through the couplings 9 and the pipe 10 from the pumping station 7.

The hearths 2 _a are inspection and cleaning hearths, but also coupling and intervention, and they have dimensions reduced compared to other consecrated in exploitation hearths; so, they have interior diameters contained between 100mm í 500mm, interior heights contained between 300mmí2 000mm, function of the frost depth, thermo- isolating degree of the conducts 1 and the hearths 2 _a , thermo gradient, passive or active, available on the length of the conducts 1 and near the hearths 2 _a ; the medium distance on vertical near the hearths 2 _a between the entering (downstream) and exit (upstream) axes of the conducts 1 is generally contained between 10 mm í 1 000 mm, function of the diameter and transversal profile of the conducts 1, the length between the hearths 2 _a and values of the slope defined by the angle "02".

The hearth 2 _a are realized either independent of the ejectors 8, which are subsequently mounted, or in inbuilt construction that contains the ejectors 8, of the following materials used integrally or combined: concrete, concrete poured under pressure into the matrix, reinforced concrete, polymers reinforced with glass/carbon fibre, ceramics, glass, armored glass, poured basalt, processed basalt, walled-up basalt, fired and enameled clay in one piece construction or as small bricks profiled and walled-up, white cast iron, stainless steel, impregnated and reinforced wood, cement, gyps treated hydrofuge, etc.

The discontinuous functioning from downstream to upstream of the ejectors 8 through manual or automation control from the pumping station 7, allows the creation of a hydraulic circulation of transport on the installation's length, at a corresponding medium speed contained between 0.5m/s í 2m/s; when the ejectors 8 do not work, the flow on the conducts 1 is, initially and for a short time, with free surface, and subsequently the flow is buried on approximately 95% of the volume of the conducts 1; and in the hearths 2 the filling and flowing is with free surface ; the flow speed between the hearths 2 in these conditions is contained in average between lcm/s í 50cm/s and depends on the values of the angles "0 ₂ ", contained in average between 0.5%o í 25%o

and "α"i, contained in average between O.5%o í 2%o; the flow of the liquid phase also takes place in the conditions when the angle "αi" = "α" = 0 %o.

During the transportation and evacuation of the heavy phase from the used waters, the medium speed on the installation increases until the admitted values contained in average between 5m/s í 7m/s by using the ejectors 8; the diameter of the conducts 1 increases proportionally to the length of the routing and of the water discharges collected from the lateral couplings (alignment with central "telescopic" collector); it is recommended for the downstream head of each conduct 1 to be used an ejector 8 represented in fig. 23. This example of the invention's realization offers a constructive solution for the sewage installation mounted at a small depth (at the frost-depth limit, or less) or/and on a big length contained in average between 200m í 5 000 m and at which the placement slope is generally contained between 0.5%o í 2%o, without excluding the medium slope contained between 0%o í l%o (which practically means a horizontal land until the purifying-treatment station 3 and / or emissary).

The application is useful to the upstream extensions of some existent sewage installations that work with a provision of capacity of transportation in downstream.

For the access to cleaning - in case of heavy clogging - with other consecrated, exterior means (scoops, flexible hoses, etc.), the distance between the downstream axle of a conduct 1 and the external face with cap of a hearth 2 is contained between

210mm í 1500mm, function of the water discharge of transportation of used waters and thermal conditions that to avoid freezing.

A case of effective supplementary cleaning from the exterior, in case of heavy clogging, is realized, in parallel to the ejectors 8 working, by introducing some masses of water through the hearths 2 with beginning from downstream to upstream through motor tank trucks, etc.

These cases of cleaning have been given because any sewage installation is possible to be clogged from various reasons, and conditions for cleaning with external means must be ensured.

The hearths 2 _a are realized so that the hydraulic apron of the hearths 2 _a is at the same level with the hydraulic apron of an ejector 8, which overflows in the hearths; the caps of the hearths 2 _a are hermetically mounted.

The conducts 1 are generally made of plastic material (p.v.c, etc.) as well as the ejectors

8, and optionally they are dressed /plated with thin plate of stainless steel.

This application allows the realization of a cheap sewage installation in unitary system with a central alignment for sewage used waters and alignments on the lateral parts of a street/path for meteoric used waters or in separating system, respectively two alignments (used sewage and meteoric waters for each lateral part of a street/path for the meteoric waters or in separating system), for long routings and gentle/zero slopes or above and in the proximity of a sewage installation that got to be inefficient. Another application is for the secondary sewage networks, including the interior network from yards, farms, etc., until the coupling hearths, when the distances from any collecting device until the hearth are reduced (contained in average between 25mí200m) as well as the small placement depths contained between 0.2m í 1.2m with reduced slopes contained between 0%o í 2%o and especially for reduced water discharges, evacuated at time periods of 30 minutes í 60 minutes with specific mass water discharges contained in average between lkg./ s í 10kg./ s in a period of 1-5 minutes.

The fourteenth example of the invention's realization also related to fig 1, 2, 23, 29 and 30 presents a sewage installation with gravity flow equipped with ejectors, of unitary or separating type, which has a buried flow through the conducts 1 placed in the longitudinal "saw-toothed" profile through the hearths 2 _a with "slope restoring"; the installation has the general flow-slope "αi" at "wave crest" in the longitudinal medium profile and it is contained between O%o í 0.5%o; the longitudinal medium profile contains the axes of the ejectors 8 from upstream of each conduct 1. The installation is formed of the conducts 1, mounted in series with the ejectors 8 on a relatively long distance between the consecutive hearths 2 _a ; the distance between the hearths 2 _a is generally contained between 50mí500m; the placement pace of the ejectors S is contained between 10m í 25m; the slope "cfc" of the longitudinal profile between the hearths 2 _a is contained in average between l%o í 5% ₀ ; "α" is the slope angle of the soil's plan compared to the geodesic horizontal of the land. The relation between "α", "α _x " and "α ₂ " is "α ₂ " > 'W > "α".

The ejectors S are periodically supplied with under-pressure technological water through the couplings 9 and the pipe 10 by the pumping station 7. The periodical control of the supplying with under-pressure technological water of the ejectors 8 is made manually or automatically from the pumping station 7.

The ejectors 8, mounted in series with the conducts 1 on the distance between two consecutive hearths 2 _a , are coupled also with the mini-hearths 41 for intervention from the exterior, for supplying with under pressure technological water from aggregates and mobile equipments (portable motor-pumps, motor tank trucks, etc.); these last facilities are useful for cleaning operations of the ejectors 8 and the conducts 1, independently of the operation of the pumping station 7.

There are admitted lateral couplings from the clients (local sources of used water) at the conducts 1 disposed between two consecutive hearths 2 _a .

TWs example of the invention's realization is useful to the applications for sewage installations that do not have convenient slopes of the soil surface on big lengths and, supplementary the placement depths are reduced because of the porous, instable constitution or with phreatic water at small depth, reduced depth of the emissary, etc.; by reduced depth we understand depths smaller than the depths that correspond to some normal flow-slopes with rectilinear longitudinal profile.

This example of the invention's realization is also useful to the applications in which is necessary the upstream extension of some sewage installation on a horizontal land with a big surface and length - in which it is not technically possible the collection through gravity flow by maintaining constant the existent flow-slope, which must be extended and got to a small provision compared to the frost-depth; generally, the sewage installations with buried flow have a thermal condition with a positive temperature gradient, due to the warming of used water through the biochemical reactions and the risk of freezing near a hearth 2 in winter time, even without cap, appears at exterior temperatures of- 2O ⁰ C and depths with 50 % smaller than the frost-depth. The thermo-isolating construction of the conducts 1 and the hearths 2 makes possible the reduction of the frost-depth with approximately 75%, which means an important resource of upstream extension of a flow alignment with gentle slope until the limit of frost-depth in the new conditions.

The fifteenth example of the invention's realization also related to fig 1, 2, 23, 29 and

30 presents a sewage installation with gravity flow equipped with ejectors, of unitary or separating type that has a buried flow through the conducts 1 placed in the longitudinal "saw-toothed" profile through the hearths 2 _a with "slope restoring"; the installation has the general flow - slope 'W at "wave crest" in longitudinal medium profile and is

contained between 0%o í 2%e>; the longitudinal medium profile contains the axes of the ejectors 8 from upstream of each conducts 1.

The installation is formed of the conducts I ₃ in construction and placement with slope and ramp between the hearths 2 placed at equal depths and distances on the length of the main alignment until the purifying-treatment station 3 or until the hearth 2 of coupling with another sewage installation.

The slope of the conducts 1 has the angle "(X ₂ " with the horizontal and the angle "β" with the ramp axis; the angle between the ramp axis and the vertical is "β ₂ ", and the angle of the ramp (counter - slope) with the horizontal of the place is "βi".

The relation between V, "αi" and "α ₂ " is "α ₂ " > "αi" > "α".

The relation between the angles "P ₁ " and "β ₂ " is the following: "β" > "β ₂ " > "βi", and the values of the angle "βi" are contained in average between 30° and 45°.

In each hearth 2 _a the downstream head of the conduct 1 is placed at the same level with the upstream head of the next conduct 1.

The length in slope of the conduct 1 is of approximately 80% í 95% from the distance between the hearths 2, and the length in ramp of the conduct 1 cannot be smaller than the length of an ejector 8 adequate to the diameter of the conduct 1.

The construction in broken line (slope - ramp) of the conduct 1, allows an easy access for cleaning with external technical means through downstream of the conduct 1 and an increasing of the hydraulic radius of the hearths 2 _a produced by the water discharges evacuated through the ejector 8 of downstream of the conducts 1; the increasing of the hydraulic radius of the hearths ensures a hydrostatic pressure approximately constant in all the hearths 2 and a resource of increasing the transport speed. The ejectors 8 and the conducts 1 are generally made of plastic material (p.v.c, etc.).

The ejectors 8, recommended for the downstream head of the conducts 1, are the ones with two clefts "b" presented in fig. 23.

The installation allows lateral couplings of the clients (punctual sources of used waters) on the alignment of the conducts 1 and in the hearths 2 _a .

This example of the invention's realization is useful to the applications of installations, for example with gravity flow on the conducts, at which the land has a gentle slope "α" contained between 0%o - 0.5%o on lengths contained in average between 25m and

5000m and at which the depth of emissary or of a coupling hearth with another sewage installation is close to the depth of the first hearth 2 from upstream and at the values of the gentle flow-slope given by the distance between them (equivalent to the length of

the entire installation) is not possible the functioning of a sewage installation in itself known, which has gravity flow with free surface through conducts and hearths, because there are reached the minimum speeds of deposition (< 0.7 m/s) and clogging (<

0.4m/s).

The sixteenth example of the invention's realization also related to fig. 1, 2, 25, 26, 32 and 33 presents a double sewage installation with longitudinal superposed alignments that is formed of a sewage installation in itself known with gravity flow with free surface through the conducts 1, placed between the hearths 2 at the hydraulic apron of them and another sewage installation with buried flow through the conducts 1, equipped with the ejectors 8, with longitudinal "saw-toothed" profile and mini-hearths 2 _a with "slope-restoring" and placed above and approximately parallel to the sewage installation in itself known.

Within the hearths 2 _a , between the ejectors 8 is optionally mounted a hearth 2b of small dimensions, which is formed of a ramification piece 42, endowed with a tightening cap 43; the cap 43 is endowed with a valve 44, in itself known, with sphere, with lifting power for liquids, for airing.

This example of the invention's realization is useful for the applications of restoring the transport capacity of a sewage installation in itself know by adding through superposing of a sewage installation with ejectors and buried flow and with a flow-slope generally gentler, in order to reduce the height of the diggings until downstream. The sewage installation with the ejectors 8 is supplied with used water from the first hearth 2 from downstream, which is common to both of the installations and independently transports the excess of used waters from this hearth until the purifying- treatment station 3 and, supplementary absorbs water discharges collected through lateral couplings from different punctual sources of used water, disposed on the placement length of the sewage installation.

The alignment with the ejectors 8 and longitudinal "saw-toothed" profile has its own hearths 2 _a with "slope - restoring" and crosses the hearths 2 of the sewage installation in itself known and placed lower through the tubular apron 38 (presented in the eleventh example of the invention's realization and in fig. 25 and 26); the tubular apron 38 endowed with an oscillating cap 39 allows the overflow of an excess of used waters or technological water at the hydraulic apron of the downstream hearths 2 _a and consecutive compared to the first upstream hearth 2 _a .

The ejectors 8 are temporarily supplied with under-pressure technological water through the couplings 9 and the pipe 10 from the pumping station 7; the control of the temporary supplying is made manually or automatically from the pumping station 7. This example of the invention's realization is also useful in the cases of the upstream extensions of a sewage installation in itself known that does not have any more slope provision and nor placement depths and which in upstream-upstream should be bigger or equal to the frost-depth of the soil.

Other explanations of this example of the invention's realization are: for the transformation of a sewage of unitary type into a sewage of separating type (independent working and transport for the used waters qualitatively different), for the realization of an experimental stand, for technical acceptance "in situ" of the constructive solutions of some sewage installations and equipments, according to some of the examples of the invention's realization and for the realization from the beginning of a sewage installations with two longitudinal superposed alignments. Within the hearths 2 and 2 _a between the ejectors 8 it is optionally mounted a hearth 2b of small dimensions, which is formed of a de ramification piece 42, closed with a cap 43, which is endowed with a blow valve 44 in itself known cu sphere with lifting power for liquids.

The last example of the invention's realization, the seventeenth, also related to fig. 1,

2, 29, and 34 presents a sewage installation with gravity flow, with free surface through the conducts 1 with/without the tubular ejectors 8 and which for sub - crossing an obstacle that occupies a depth from the subsoil, such as: buildings, subway, railway in cut, underground cables of low and high tension, irrigation channels, oil conducts, streambeds, etc., is in longitudinal profile with slopes and ramps (counter - slopes) equipped with tubular ejectors 8; the longitudinal profile is in itself known with the name "in inversed siphon" and it is equivalent to a pace/ module of a longitudinal "saw- toothed" profile (presented above in the invention's description), placed between two hearths 2 and 2 _a , consecutively placed on the alignment, on each side of the obstacle, which in this example is the bed of a running water.

The flow of a used water from the hearth 2, considered "of upstream" is with buried flow and is made through an tubular ejector 8, then through the conducts 1 disposed in a succession of slopes at the angle "αi" decreasing, and farther, through a conduct 1 in slope at the angle "βi" and through the tubular ejector 8 in the hearth 2 _a , considered "of

downstream"; the hearth 2 _a is a hearth with "slope restoring" - a hearth with slope restoring operates inverse compared to the known hearths with "slope breaking".

In the hearths 2 and 2 _a are optionally mounted within them the hearths 2 _b with tight cap, which couples to the conducts 1/tubular ejectors 8, for tightening the installation, because the sewage with buried flow also produce the partial fermenting of the used waters.

In the hearths 2 and 2 _a common for two alignment of sewage of separating type with flow with free surface, in the network of conducts 1, with/without ejectors 8 and placed in under - crossing there are mounted within the hearths 2 and 2 _a the hearths 2b with tight cap, for the network of transportation of used sewage waters, and the volume between the interior of the hearths 2 and 2 _a and the exterior of the hearths 2b is used for the network of transportation of meteoric waters, especially pluvial.

The ejectors 8 are discontinuously supplied with under-pressure technological water from the pumping station 7 through the pipe 10 and the couplings 9.