Description

The invention relates to a process for realising channelling modules for air distribution and/or diffusion plants and a conduit obtained with the process.

In particular the present invention relates to a process for realising conduits preferably though not exclusively used for distribution of treated air for conditioning an environment, such as for example cooled air, hot air, filtered air or the like.

Air distribution plants usually comprise a channelling through which an appropriate amount of air is transferred from a devices destined to generate an air flow (for example a fan) to a zone of use, such as for example a particular environment such as a room, an office, a workshop, a large shed or the like.

The channelling is usually made up of one or more metal-sheet conduits and one or more terminal diffusion ducts, such as perforated diffusion channels made of metal sheet or flexible metal.

Transport and diffusion conduits can be made of metal and have the task respectively of transporting and diffusing air homogeneously in the zone of use and, in the case of high-induction plants, the metal diffusion channels are provided with a plurality of diffusion holes arranged along a lateral wall of the conduit in order to inject air into the environment to be treated.

As is known, each conduit, which generally exhibits a substantially circular- section tubular conformation, is obtained by means of bending a flat sheet of metal sheet. In particular the flat sheet, normally rectangular in plan (if necessary previously perforated) is made to pass through special calendering cylinders which bend and impart the arched circular shape on the metal sheet.

Subsequently respective longitudinal side edges are constrained to close the sheet, defining the tubular circular-section conformation of the conduit.

Generally the longitudinal edges are joined to one another by cramping and/or welding. In this situation, before the shaping stage the sheet is bent at the longitudinal edges in order to create respective projecting turnovers on opposite surfaces of the sheet. These turnovers, once the sheet has been fashioned, enable the sheet to be hooked up along what will become the lateral wall of the channelling module; the turnovers are then pressed to define a longitudinal superposing zone, and an unremovable engagement of the edges.

The conduit is preferably also welded at two end points of the longitudinal zone, such as to guarantee a stable constraint between the two longitudinal edges. The circular opposite ends of the conduit are then bent outwards in order to define a pair of lateral abutments projecting radially from the metal sheet.

In other words, the circular edges defining the ends of the conduit are bent in order to emerge from the external cylindrical surface of the tubular sheet.

In this way, during the fitting of the plant, the conduits are coupled to one another by constraining the lateral abutments of two adjacent conduits.

This operation is generally done using special circular bands that surround the join zone of two consecutive conduits in order to fasten the lateral abutments of the conduits.

The above-described conduits and the relative realisation process, however, exhibit important drawbacks. Firstly, it is known that air distribution plants can be particularly long and thus be made up of a very high number of tubular modules.

Consequently, numerous single modules have to be transported, and once coupled they define the channelling with the consequent disadvantages in terms of overall size and costs of the transport and in general the logistics.

Moreover, note that each conduit, which defines an internal air passage channel, exhibits volumetric dimensions that are quite large and therefore the transport of the conduits is not only problematic but also particularly expensive given that generally costs of transport are calculated in terms of volume.

This drawback is also relevant in storage arrangements. The conduits cannot be finished in the worksite, so large numbers of them have to be pre-formed and stored, and also graded according to the various sizes and use destinations.

Where it is possible, the most that can be done is that conduits of different diameters are inserted into one another in order to optimise space and transport costs.

Further, each module has to be specially packed and protected in order to prevent damage during transport.

In this context, the technical objective at the base of the present invention is to provide a process for realising channelling modules for air distribution plants and a respective module obtained by means of the method, which is able to obviate the drawbacks in the above-cited prior art.

In particular, the present invention aims to provide a conduit for air distribution and diffusion plants which is capable of limiting the overall sizes and also the costs of the respective operations of storage and transport. An objective of the invention is to provide a simple and economical process for realising conduits for air distribution plants, and for the protection thereof during transport, as well for increasing the ease of installing the conduits.

The above-set technical objective and the set aims are substantially attained by a process for realising modules for air distribution plants, comprising the technical characteristics cited in one or more of the appended claims.

Further characteristics and advantages of the present invention will better emerge from the non-limiting description that follows of a preferred but not exclusive embodiment of a process for realising modules for air distribution plants, as illustrated in the accompanying figures of the drawings, in which: figure 1 is a schematic view of a production plant of channelling modules of the invention;

figure 2 is a lateral view of a part of the plant of figure 1 ;

figure 3 is a perspective view of a first semi-finished workpiece for the following stages of realising a conduit for air distribution plants;

figure 4 is a lateral raised view of an upturned calender press for realising the conduit for air distribution plants;

figure 5 is a frontal raised view, with some parts removed better to illustrate others, of the conduit during the second stage of realisation of figure 4;

figure 6 is a perspective view of a conduit for air distribution plants according to the present invention;

figure 7 is a perspective view of a series of conduits of the type illustrated in figure 6, in a respective stage of partial stacking;

figure 7a is a transversal section of a plurality of modules inserted one into another for operations of storage and transport; figure 8 is a perspective view of an air distribution plant made up of a series of conduits of the type illustrated in figure 6;

figures 9 and 9a are section views of two possible alternative constraint systems of successive modules;

figures 10a- 10c are schematic representations of the stages of assembly of a channelling module.

With reference to the figures of the drawings, a channelling module for air distribution plants of the present invention has been denoted in its entirety by 1. The module 1 is obtained starting from a sheet 2 having a flat conformation and being preferably made of metal.

In particular, looking at figure 1, the plant for realising the open channelling module is curved with a circumference having a controlled deformation, in which a sheet is continuously unwound from a reel 100, flattened and then cut at a cutting station 101; in this way it is possible to establish a desired length of the single sheets which, due to how the production plant is designed, will consequently substantially define the dimension (length) of the circumference of the finished module.

Further, appropriate reference portion or portions 5 are defined at the station (or alternatively in preceding or subsequent stations), and are more fully described in terms of geometry and function herein below.

At this point the metal sheet 102 having a generally rectangular shape with transversal dimensions defined by the transversal dimensions of the reel 100 and longitudinal dimensions selected according to the dimensional needs of the channel to be realised is worked by an edging tool 103, i.e. a machine used in working of metal sheet and used for bevelling the edges of the metal sheet. As well as being edged, the plant also includes a station 104 in which perforations 15 (if necessary) are made.

An important point is that if the module is destined to define a diffusion channel, it will exhibit perforations 15, made during the production process, as defined in the figures, at the lateral zones and along the transversal direction of the metal sheet such that in use the perforations enable air to be sent towards the environment external of the channel and the corresponding movement of the air of the external environment of the channel essentially by induction; to this end the perforations can be in numbers and of dimensions selected (generally not homogeneous in the perforation dimensions and the distribution of the perforations) in order to optimise the performance of the plant, moving the correct quantities of air, and in any case avoiding, during use, the creation of unpleasant draughts at ground level; if on the other hand the module is destined to define an air transport channel the perforations will usually not be present. Note that the perforations 15 realised in the metal sheet, which will define diffusing channels, are configured such that once several diffusion modules are coupled to one another, the perforations define two tracts arranged on the channel surface which develop in the longitudinal development direction of the channel. Note however than diffusion channels (perforated) and transport channels (not perforated) can be alternated or in any case arranged in any sequence according to the particular design.

In this way at the end of the first working stage of the product a flat sheet is obtained having reference portions, appropriately perforated and edged and of the desired dimensions for realising the channelling module of the invention. In this situation a plurality of sheets 105 are stacked on one another and arranged on appropriate platforms 106 (one or more platforms 106 will be available in series according to loading/stacking requirements).

In particular the raising platforms 106 will be provided with special movement means (such as a bridge crane, a roller plane and others besides) in order to advance the sheets 105 towards the subsequent work stations along the advancement direction A (figure 1).

In this situation a loader (not illustrated inasmuch as of known type and conventional) will be able to pick up the metal sheets 105 one-by-one in order to send them towards a shaping station 107.

The metal sheet 105 is deformed in the shaping station 107 such that the sheet 105 on exit exhibits two lateral abutments 6 which in the end product will define end edges radially emerging in order to enable constraint of successive modules and to define the conditioning plant (see figure 8).

The deformation is realised by bending, such that the lateral edges 6 emerge (for example at right angles) from the lie plane of the sheet. In the accompanying figures of the drawings these edges are illustrated as being continuous and extending substantially along the whole longitudinal development of the metal sheet 105, on both sides; however it is possible, though more complex and less reliable, for the edges 6 to extend only over a portion of the whole longitudinal development (for example only in a central zone) or for two or more edges 6 to be present on at least one and in general on each opposite side of the metal sheet 105. In this case, a part of the metal sheet could be appropriately cut (before bending), which part would define the edges such as to create empty zones alternating with full zones at the lateral portions. Obviously only the full zones would define the lateral edges after deformation.

Obviously the operation of realising the previously-described reference portions 5 can also be performed at further work stations, for example in the shaping station, without forsaking the aim of the present invention.

It is specified, as previously mentioned, that the metal sheet 2 can be further perforated in order to define a series of air diffusion passages 15. However, for the sake of greater clarity, figures from 3 to 10 illustrate metal sheets 2 not exhibiting perforations, used only for air transport (the object of the invention comprises both embodiments and it is therefore understood that the operations described and actuated in relation to the non-perforated sheet are equally applicable to the sheet with perforations 15).

The metal sheet 2 exhibits means for constraining 1 1 the opposite longitudinal edges 4 comprising at least the cited reference portion 5.

In particular, each longitudinal edge 4 illustrated exhibits a single reference portion 5 constituted by a recessed zone having for example a trapezoid section (obviously straight or partly curved sections are also comprised within the ambit of protection of the invention); each recessed zone of the reference portion 5 is complementarity shaped to the corresponding recessed zone in the other longitudinal edge 4 such that during coupling of the opposite longitudinal edges of each module, the reference portions couple to one another and guarantee excellent assembly. For this purpose it is clear that although each recessed zone illustrated runs parallel to the edge of the metal sheet, it is possible that the might not be parallel to the edge as long as once engaged to one another the module is in a completed-channel configuration, ready for definitive blocking, and the longitudinal edges can thus be rigidly fixed to one another.

The reference portions 5 are normally realised in a drawing stage performed by means of a press which is not illustrated as it is of known type.

In this way a series of recessed zones 5a is defined in a first surface 2a of the metal sheet 2, opposite respective projecting zones 5b extending from a second surface 2b opposite the first surface 2a.

Note that, especially with large-diameter channels (~ 1500 mm), for each side two or more of the reference portions 5 can be used.

Further, the means for constraining the module comprise a predetermined number of perforations 16, made in the projecting zones 5b and the recessed zones 5a.

As will more fully emerge herein below, the perforations 16 enable passage of respective coupling organs such as screws or rivets or the like.

It is clear that reference portions 5 can be made having completely different geometries and shapes from those illustrated herein, and will in any case enable the further operations described herein below to be described.

Purely by way of example, for each longitudinal edge 4 a plurality of single deformations can be realised (bumps), arranged substantially along the whole longitudinal edge 4 (or even only at some parts of the edge 4 such as the end portions).

In a further embodiment, not illustrated, the reference portions 5 can be constituted by terminal projecting lips along the transversal development of the metal sheet and at the free transversal edges (longitudinal edges 4) such as to be able to define reciprocal coupling portions which guarantee correct positioning of the module before mounting thereof, as will be more clearly described herein below.

In an extremely simplified embodiment simple reference marks present on a longitudinal edge and the other longitudinal edge could be used as reference portions 5; these marks will, for example, be superposed to indicate that the correct reciprocal positioning of the edges has been attained before constraint is made final (in this sense the reference portions can be, or not, the through-holes 16 for locking.

However making only reference marks is in general not sufficient as this method does not provide any help in maintaining the reciprocal positioning; on the other hand, the reference portion 5 defined, for example, by (small) deformations of the opposite edges of the metal sheet help (at least partially) in maintaining the reciprocal position and facilitate final assembly of the module.

Expressed in another way, the reference portions 5 define reciprocal coupling surfaces of the opposite longitudinal edges 4 to be exploited during assembly of the module (closure along the longitudinal axis of the module in order to define a tubular channel open only at ends thereof).

Still further embodiments are possible.

Still with reference to figure 3, note that the metal sheet 2 further exhibits two lateral abutments 6 realised at the respective transversal edges 3.

Each lateral abutment 6 is advantageously defined by a bending stage performed on the transversal edge 3 above the first surface 2a of the sheet 2. The lateral abutments 6 are preferably brought up to each other and extend perpendicular to the planar development of the metal sheet 2. In this case too, the bending stage

IO of the transversal edges 3 for defining the abutments 6 is performed by a press, not illustrated in detail as of known type.

The metal sheet 2 can further comprise one or more longitudinal reinforcements 18 (for example having a semicircular section) that are substantially parallel to the edges 3 (and the abutments 6 if present) located between the reference portions 5.

The reinforcements 18 (optional) have the aim of guaranteeing a sufficient structural rigidity of the module, in particular if destined to realise large- diameter channels.

The above-described flat sheet 2 is then bent (curved) to near the longitudinal edges 4 to one another, defining a substantially tubular shape for the metal sheet 2.

In more detail, as is better illustrated in figures 2, 4 and 5, the flat sheet 2 is passed through a series of shaping cylinders 7 destined to form the metal sheet 2 into a substantially tubular shape.

With particular reference to figure 6, the metal sheet is bent with the respective convex first surface 2a facing upwards and the concave second surface 2b facing downwards such that the abutments 6 take on a curved shape.

Also, during the shaping stage, the metal sheet 2 is folded progressively, by nearing the respective longitudinal edges 4 to one another and defining a substantially spiral conformation of the sheet 2. The tubular shape of the sheet 2 exhibits a spiral transversal section development, i.e. a respective open zone 17 defined by the distance between the longitudinal edges 4. In this situation, the longitudinal edges 4 are arranged at different distances (d; d') from a longitudinal development central axis X of the metal sheet 2.

I l In other words, the degree of curvature defined at the most internal longitudinal edge will be less than the degree of curvature defined at the radially more external longitudinal edge; in optimal conditions the degree of curvature will increase following the circumference of the open and curved module starting from the internal edge up to arriving at the radially more external longitudinal edge.

Obviously the fact of having left the module open (zone 17) and having shaped it in a spiral also leads to an angular staggering (α; α') of the edges 4 (figure 10) with respect to the assembly condition of the edges themselves (figure 10c). In other terms, the metal sheet which will define the channelling module is appropriately deformed such as to take on, in section, a spiral shape, or a spiral having a circumference with a precisely controlled deformation.

In still other terms, apart from being arranged at different distances from the longitudinal development axis X of the metal sheet, the longitudinal edges 4 are also angularly staggered with respect to the axis X.

The opening 17 defined on each module enables other similarly-produced modules to be housed internally of a thus-realised module, by exploiting the elasticity of the metal material and the elasticity guaranteed by the open configuration (see figure 7a).

As is better illustrated in figure 5, during the shaping stage the abutments 6 of the metal sheet 2 are arranged externally of the rollers 7. In this way, the action of the rollers 7 is performed directly on the first and the second surface 2a, 2b, while the abutments 6 are maintained at the ends of a respective roller 7, such as to guide the metal sheet 2 along the shaping direction. The thus-obtained metal sheet 2 (figure 6) defines an internal channel 8 (opening longitudinally due to the spiral section) which in the operating condition of the conduit 1, i.e. when the module is finished), enables passage of air.

For example the maximum diameters of a finished channelling module will be around 1600-1700 mm.

With particular reference to figure 7a, a transport and storage condition of a series of modules 1 is illustrated, with the modules 1 telescopically associated to one another.

In greater detail, and still with reference to figure 7a, the internal channel 8 of the more external metal sheet 2 contains a further metal sheet 2b, 2c, also spiral- shaped.

Purely by way of example, modules having a final diameter of 250 mm can be packed in twos, threes or fours; with final diameters of between 500 and 800 mm about ten modules can be packed, while diameters of 1600 mm enable from 30 to 50 modules can be packed.

The longitudinal edges 4 of the most external sheet 2a can advantageously be distance from the longitudinal development axis X in order to increase the size of the internal channel 8 such as to enable further metal sheets to be contained. The realisation of each spiral-shaped module enables the channelling module to retain a certain degree of deformation elasticity and thus enables coupling by insertion of a plurality of modules, which thus optimally occupy the first module's space, which situation would be impossible in a case in which the channelling module were already completely assembled to define a substantially undeformable circular section (figure 7a). The metal sheets thus-associated are stored or transported up to the installation place, where the respective air distribution plant 10 partially illustrated in figure 8 is to be installed.

At the work-place, the metal sheets 2a, 2b, 2c are extracted from one another (generally while keeping the pack of metal sheet with its axis vertical, as in figure 7) and deformed in order to return to a respective functioning condition. The functioning condition is defined simply by joining the opposite longitudinal edges 4 of each spiral-shaped metal sheet 2, in order to give the sheets 2 themselves a circular and closed transversal development (figures 1 Oa - 1 Oc). In other words, the longitudinal edges 4 defining the open zone 17 of the sheet 2 are anchored to one another in order to close the metal sheet 2 and define a tubular structure which tends to return to a circular section.

In particular, a longitudinal edge 4 is superposed on the opposite longitudinal edge 4, such as to place the first surface 2a partially in contact with the second surface 2b. In this way, the projecting portions 5b of the superposed edge 4 are inserted in the respective recessed portions 5a of the superposed longitudinal edge 4 (or vice versa) (figure 10b).

Further, locking screws (not illustrated as of known type) can be inserted in the perforations afforded in the reference portions 5 (or even in proximity thereof), which screws fasten the edges 4 to one another.

In other words, the reference portions 5 enable guiding, during laying, the opposite longitudinal edges up to reaching the correct fastening position; in this fastening position, respective holes present in the opposite longitudinal edges are superposed and are in a suitable condition for being fastened by screws, rivets or similar constraint elements. In this condition, the conduits 1 are brought up to one another and constrained at the respective transversal edges 3, in order to define a succession of conduits 1 defining the plant 10.

In particular, the abutments 6 of two adjacent conduits 1 are brought side-to-side and anchored using a respective band 9, not illustrated or described as of known type.

The band 9 exhibits a substantially annular conformation in order to extend about the conduits 1, at a joining zone of the conduits 1. The band 9 further exhibits respective hooking organs for keeping the abutments 6 anchored to one another and also for keeping the internal channels 8 of the adjacent conduits in fluid communication.

It is obvious that the fastening achieved with the band leads to a generation of forces, not only locking forces, but also destined to return the channelling module to its circular shape should it have partly lost its correct geometry following excessive deformation thereof.

Alternatively, engaging elements 9 can be used which are different and destined to be inserted in the conduits 1. The elements, schematically illustrated in figures 9 and 9a, do not require constraining to the abutments 6 (which might even be omitted) and are constrained to the transversal edges 3, at the joining zone between two conduits 1.

The example of figure 9 shows an internal element 9 provided with a central reinforcing rib facing towards the outside of the channel; figure 9a, on the other hand, illustrates the use of two semi-elements 9a-9b provided with three reinforcing ribs facing towards the inside of the channel such as to guarantee both an optimal structural reinforcement and an absence of discontinuity seen from outside the channel.

Note that the above-described conduits 1 can be stored and transported while considerably reducing the overall volumes thereof.

The advantage is provided by the module 1 realisation process, which comprises a stage of obtaining a semi-finished work-piece constituted by the metal sheet 2 having an open-arch configuration, in general having a spiral structure. The metal sheet 2 enables containing further sheets 2, again spiral-shaped with a circumference having a controlled deformation such as to exploit the space defined by the internal channel 8 for containing a predetermined number of metal sheets 2.

Consequently the volumetric dimensions caused by the presence of numerous modules 1 are considerably reduced; the modules 1 are definitively formed, i.e. closed in the tubular conformation, only during the installation thereof.

By its very nature the stacking as realised protects the internal sheets from eventual damage due to impacts and enables considerable time-saving and packaging costs.

Note also that the procedure is particularly simple and rapid in the installation operations, given the structure of the metal sheet 2 itself.

In particular, the presence of the reference portions 5 guarantees and immediate and simple assembly and also a stable constraint between the longitudinal edges

4. Also, the formation of the abutments 6 previous to the forming stage (in the flat condition of the metal sheet 2) is particularly simple and easy.

Further, the use of removable constraining means 1 1 enables access at all times to the inside of the channelling which therefore also becomes suitable for housing electric cables, piping, further conduits such as those for compressed air, etc.