DESCRIPTION

The invention relates to a sanitation system for aeraulic systems.

An ejector device, which is part of the sanitation system for aeraulic systems according to the invention itself is also to be considered an object of the invention.

Nowadays, the function of a network of pipes in an aeraulic system is to convey air, or other gases (obviously not harmful), from a unit in which the air is treated to a certain number of rooms to be supplied, or it is to extract air, or gas, from a certain number of environments to permanently expel it or to treat it again.

Aeraulic systems are to be considered, for example, the systems for the forced ventilation of the rooms of a hospital; through these aeraulic systems an attempt is made to reach a certain level of well-being in a well-defined number of spaces, where for such spaces there may be an obligation to control all the most important parameters, such as: hygiene, temperature, relative humidity, purity, speed and fire safety.

Generally, an aeraulic system comprises at least the following main parts:

- an air treatment unit (A.T.U.), with filters, heat exchangers (heating, cooling, condensation), humidifier, droplet separator;

- fans for air circulation;

- network of pipes, or channels, for air;

- air diffusion or return apparatuses;

- automatic control devices for the most important parameters such as air temperature, flow rate, and others.

In recent years, cleaning aeraulic channels has been scientifically regarded as an essential operational phase to ensure the safety of indoor environments.

In fact, national and international regulations may require the employer, or a person in charge, to carry out chemical, physical and biological risk assessments of their facility; Italian law, for example, stipulates that systems must be periodically inspected, maintained, cleaned and sanitised to protect the health of workers, and that any sediment or dirt that could pose an immediate danger to workers’ health, due to pollution of the air they breathe, must be removed quickly.

For example, in Italy, an agreement between the State and the Regions in 2013 stipulates that the recommended frequency of visual inspections for an aeraulic system is generally annual, while for hospitals, nursing homes and extended care units the frequency of visual inspections must be every six months.

These regulations create a clear problem, since the rapid elimination of a hazard is in practice not feasible if controls are carried out, at best, every six months.

Experience in the industry shows that generally, after cleaning and sanitising an aeraulic system, the filters and channels show dirt again even after only one month, and yet monthly maintenance would not be economically viable for most owners and operators of the aeraulic system.

The task of the present invention is to develop a sanitation system for aeraulic systems capable of remedying the aforementioned drawbacks and limitations of the prior art.

In particular, an important aim of the present invention is to develop a sanitation system capable of sanitising the air inside a channel of an aeraulic network drastically lowering the danger of chemical or biological hazards occurring between two cleaning activities far apart in time.

Another aim of the invention is to develop a sanitation system that is able to provide a correct treatment for sanitising the air according to the working conditions (air flow of the A.T.U. system).

The task, as well as the aforementioned aims are achieved by a sanitation system for aeraulic systems according to claim 1 .

Further features of the sanitation system according to claim 1 are described in the dependent claims.

The task and the aforesaid objects, together with the advantages that will be mentioned hereinafter, are indicated by the description of an embodiment of the invention, which is given by way of non-limiting example with reference to the attached drawings, where:

- Figure 1 represents a diagram of an ejector device of a sanitation system of an aeraulic system according to the invention;

- Figure 2 represents an aeraulic system comprising a sanitation system according to the invention;

- Figure 3 represents a schematic cut-out of a detail of the sanitation system according to the invention; - Figure 4 represents another diagram of the ejector device of Figure 1 ;

- Figure 5 represents a diagram of an embodiment variant of the sanitation system according to the invention.

With reference to the aforementioned Figures, a sanitation system according to the invention is indicated as a whole with the number 10.

This sanitation system 10 for aeraulic systems comprises:

- a treatment unit 11 configured to treat air coming from an external environment;

- a delivery fan 12, schematically shown in Figure 2, configured to draw air from an external environment and pass it through said treatment unit 11;

- a delivery pipe 13 configured to receive air treated by said delivery fan 12 and to supply a network of pipes 14 for the air in turn comprising one or more distribution lines 14a, 14b, 14c, 14d, as represented in Figure 2;

- a plurality of introduction terminations 15, 15a, 15b, 15c, 15d positioned on said distribution lines 14a, 14b, 14c, 14d; each of the introduction terminations 15, 15a, 15b, 15c, 15d is configured to allow the passage of air treated by the corresponding distribution line 14a, 14b, 14c, 14d to an internal environment 16, 16a, 16b, 16c respectively supplied; a first introduction termination of said plurality of introduction terminations, for example the introduction termination 15a, is the closest to said delivery fan 12, i.e. it is that introduction termination that is geometrically less distant from the delivery fan 12 than the other introduction terminations.

The sanitation system 10 according to the invention comprises an ejector device 20, schematically shown as a whole in Figure 1 , configured to introduce a sanitising substance into said delivery pipe 13 at a point between the delivery fan 12 and the first introduction termination 15a.

The term ‘delivery pipe’ is intended to mean the pipe comprised between an exit point 12a of the delivery fan 12 and an entry point 13a of said pipe in a first internal environment 16 to be air-conditioned, as schematically shown in Figure 2.

The treatment unit 11 is to be understood as an A.T.U. of the type known in itself.

The ejector device 20 comprises, as schematically shown in Figures 2 and 4:

- at least one dosing syringe 21, comprising a cylinder 23, a piston 25, a stem 27 for moving the piston 25, a dosing chamber 29 defined between the cylinder 23 and the piston 25;

- actuator means 32 configured to move the stem 27 according to a backward movement for sucking a sanitising substance towards the interior of said dosing chamber 29, and according to an opposite forward movement for the expulsion of said sanitising substance from said dosing chamber 29;

- a collection tank 36 containing said sanitising substance, indicated symbolically by A;

- a spray nozzle 40 arranged inside said delivery pipe 13;

- a collection conduit 41 configured to connect the collection tank 36 to the dosing chamber 29;

- an injection conduit 43 configured to connect the dosing chamber 29 with the spray nozzle 40.

Preferably, but not exclusively, the ejector device 20 comprises a mixing chamber 45 arranged on the injection conduit 43; the mixing chamber 45 is connected:

- at a first connection entry 45a with a first section 43a of the injection conduit 43 for the entry of said sanitising substance A coming from said dosing chamber 29;

- at a second entry 45b with a pressurized air line 46 adapted to mix the sanitising substance A with air and to push a mixture of sanitising substance A and air towards said spray nozzle 40;

- at an exit connection mouth 45c with a second section 43b of said injection conduit 43, which second section 43b is connected with said spray nozzle 40.

In the embodiment of the invention described herein, by way of non-limiting example of the invention, the ejector device 20 comprises:

- two dosing syringes 21 and 22, each comprising a cylinder 23 and 24, a piston 25 and 26, a stem 27 and 28 for the movement of said piston 25 and 26, a dosing chamber 29 and 30 defined between the respective cylinder 23 and 24 and piston 25 and 26;

- actuator means 32 configured to move said stems 27 and 28 according to a backward movement for sucking a sanitising substance towards the interior of the dosing chamber 29 and 30, and according to an opposite forward movement for the expulsion of said sanitising substance from said dosing chamber 29 and 30; - two collection tanks 36 and 37 each containing a corresponding sanitising substance A and B;

- two respective collection conduits 41 and 42 each of which is configured to connect a respective collection tank 36 and 37 to the corresponding dosing chamber 29 and 30;

- two respective injection conduits 43 and 44, each configured to connect a respective dosing chamber 29 and 30 with the mixing chamber 45.

The mixing chamber 45 is therefore unique.

The mixing chamber 45 is connected:

- at a first entry 45a with the first section 43a of the injection conduit 43 for the entry of the first sanitising substance A coming from a first dosing chamber 29;

- at a second entry 45b with the pressurized air line 46 adapted to mix said sanitising substance with air and to push a mixture of sanitising substance and air towards said spray nozzle 40;

- at a third entry 45d with the second injection conduit 44 for the entry of a second sanitising substance B coming from a second dosing chamber 30;

- at the exit mouth 45c with a section, for example the second section 43b, which connects the mixing chamber 45 with said spray nozzle 40.

For example, and preferably, the first entry 45a and the third entry 45d are defined by a three-way fitting 47 connected to said mixing chamber 45.

In particular, the collection conduits 41 and 42 each comprise a first non-return valve 48a and 49a respectively, configured and positioned so as to prevent the return of the sanitising substance A and B respectively from the dosing chamber 29 and 30 to the tank 36 or 37 of origin.

In addition, the injection conduits 43 and 44 each comprise a second nonreturn valve 48b and 49b respectively, configured and positioned to prevent the return of the sanitising substance A and B exiting the dosing chamber 29 and 30 towards the same dosing chamber 29 and 30.

In particular, each second non-return valve 48b and 49b is interposed between the three-way fitting 47 and the respective dosing chamber 29 and 30.

The pressurized air line 46 is supplied by an auxiliary compressor 51.

On the pressurized air line 46, too there is a non-return valve 52 configured and positioned in such a way that the mixture of sanitising substances A and B with the air cannot leave the mixing chamber 45 from the side of the second entry 45b.

In the present non-limiting embodiment of the invention, the spray nozzle 40 is of the pneumatically operated type.

The auxiliary compressor 51 also supplies a compressed air control line 53 for switching the spray nozzle 40 on and off.

This compressed air control line 53 is governed by a switch 54, the activation of which causes compressed air to pass in the control line 53, with consequent switching on or off of the spray nozzle 40.

In an embodiment variant thereof, schematically shown in Figure 5, the sanitation system according to the invention is characterized in that the ejector device 20 comprises a mixing chamber 145 connected at the entry with two injection conduits 143 and 144, each of which is configured to connect a respective dosing chamber 29 and 30 with the mixing chamber 145.

The mixing chamber 145 is connected, at the exit, with two storage tanks 170 and 171 for a mixture of sanitising substances A+B.

The mixing chamber 145 is connected with a first storage tank 170 by means of a first storage line 170a and with a second storage tank 171 by means of a second storage line 171a.

Each storage tank 170, 171 has a respective entry solenoid valve 172, 173 and a non-return valve 174, 175 at the exit.

The first 170 and second 171 storage tanks are connected at the exit with a same single end line 143b that connects them with said spray nozzle 40.

Each storage tank 170, 171 comprises, as already described above, a second entry connected with a pressurized air line 146a, 146b adapted to mix said mixture of sanitising substances A+B with air and to push said mixture of sanitising substance and air towards said spray nozzle 40.

In this embodiment variant of the sanitation system according to the invention there are therefore two parallel storage circuits, which are controlled by means of the solenoid valves 172 and 173 so as to operate in an alternating manner, that is, when the spray nozzle 40 receives mixture from the first storage tank 170, the second storage tank 171 is open at the entry and is filled with mixture of substances A+B, whereas, when the first storage tank 170 is substantially empty, then similarly the solenoid valves are switched so that the first storage tank 170 is filled and the second storage tank 171 can supply mixture to the spray nozzle 40. The non-return valves 174 and 175, also called unidirectional valves, are calibrated so as to open only following the exceeding of an opening pressure value that is determined in the corresponding storage tank 170 and 171 when the corresponding pressurized air line 146a or 146b is activated.

By way of non-limiting example, the actuator means 32 comprise a translation actuator 33 comprising a movable part 34 to which both said stems 27 and 28 are fixed, as clearly schematically shown in Figure 4.

This translation actuator 33 is intended to be able to be mechanical, or pneumatic, or hydraulic, or electrical, depending on the needs and specific technical needs.

The sanitation system 10 also comprises a flow sensor 50, schematically shown in Figure 3, positioned in the delivery pipe 13 upstream of said spray nozzle 40 with respect to the direction of the air flow.

The spray nozzle 40 is mounted, for example and preferably, inside the delivery pipe 13 within a distance of 4-5 meters from the air delivery, i.e. from the exit point 12a of the delivery fan 12.

Still for example, this spray nozzle 40 is clamped on a plate 70, schematically shown in Figure 3, together with the flow sensor 50.

In particular, the flow sensor 50 is positioned immediately before the spray nozzle 40 with respect to the direction of the air in the delivery pipe 13.

The flow sensor 50 is configured to calculate the actual air flow out of the delivery pipe 13.

The spray nozzle 40 is installed in this position to allow time for the mixture of sanitising substances to evaporate before reaching the first introduction termination 15a, and preferably to allow time for the mixture of sanitising substances to evaporate as far away as possible from the first introduction termination 15a.

The flow sensor 50 is installed on the plate 70 together with said spray nozzle 40, positioned before it with respect to the air flow.

For example, but not exclusively, the plate 70 consists of a metal sheet cut from the delivery pipe 13, which plate 70, once assembled with the spray nozzle 40 and the flow sensor 50, is then fixed again to cover the window on the delivery pipe 13 from which it was drawn.

The flow sensor 50 can, for example, be a ‘Pitot tube’ type sensor because it is more durable than the other sensors; the Pitot tube measurement system bases its operation on the definition of total pressure; this flow sensor 50 therefore comprises two pressure outlets, one at the front end arranged tangentially to the current and one on the body of the delivery pipe 13, arranged perpendicular to the air flow; the difference between the two pressures is calculated to calculate the flow velocity, which flow velocity, compared to the size of the section of the delivery pipe 13, determines the actual flow rate in real time.

The sanitation system 10 according to the invention also comprises an evaporation sensor 60, schematically shown in Figure 3, configured to detect the degree of evaporation of the chemicals A and B in the air flow exiting the delivery pipe 13.

Such an evaporation sensor 60 is, for example, an electrochemical cell sensor. This evaporation sensor 60 is preferably, but not exclusively, positioned near the first introduction termination 15a.

This evaporation sensor 60 is then configured to control the degree of evaporation of the sanitising substances A and B with respect to an emission threshold value, for example a safety threshold value established by a current law.

The sanitation system 10 according to the invention also comprises an electronic control unit, not represented for simplicity’s sake, which is configured:

- to receive the signal from the flow sensor 50 and calibrate the quantities of one or more sanitising substances A and B, to be delivered through said spray nozzle 40, which are proportional to the detected air flow, and

- to receive the signal from said evaporation sensor 60, so as to monitor the possible exceeding of a safety threshold of the concentration of the chemical agents present in said sanitising substances A and B, and possibly stop the delivery of said sanitising substances A and B by the spray nozzle 40.

Therefore, the software of the electronic control unit, which can for example be a PLC of the type known in itself, through the flow 50 and evaporation 60 sensors, located inside the delivery pipe 13, detects the actual air flow rate, calibrating the sanitation cycles accordingly to keep the air sanitised and avoid an excessive product consumption. The safety evaporation sensor 60, installed downstream of the delivery pipe 13, monitors the possible exceeding of the safety threshold on the concentration of chemical agents, thus blocking the work cycle.

The air treatment unit 11 is to be understood of the type known in itself, i.e. it can comprise:

- one or more air filters,

- a pre-heating battery 11 A, if necessary,

- a cooling and dehumidification battery 11 B,

- a humidifying section 11C, when necessary,

- a post-heating battery 11 D.

Preferably, immediately after the post-heating battery 11 D, there is the delivery fan 12.

The treatment unit 11 is to be understood as also being able to comprise a return pipe 80 and a return fan 81 which are configured to extract air from the interiors, as well as a recovery system 82, where such components are to be understood as being of the type known in itself.

An ejector device 20 as such, is also intended to be the object of the invention, such ejector device 20 being to be understood as described above.

Practically, it has been established that the invention achieves the intended task and objects.

In particular, with the invention, a sanitation system for aeraulic systems has been developed capable of sanitising the air inside a channel of an aeraulic network, drastically lowering the danger of chemical or biological hazards occurring between two cleaning activities far apart in time.

In addition, with the invention a sanitation system has been developed that is able to provide a correct sanitising treatment of the air according to the working conditions, or according to the air flow of the A.T.U. to which the system is associated.

In addition, a safe and automatic sanitation system has been developed with the invention.

The invention thus conceived is susceptible to many modifications and variants, all falling within the same inventive concept; furthermore, all the details can be replaced by other technically equivalent elements.

In practice, the components and materials used, as well as the dimensions and contingent shapes, as long as they are compatible with the specific use, can be any according to requirements and the state of the art. Where the characteristics and techniques mentioned in any claim are followed by reference marks, such reference marks are intended to be affixed solely for the purpose of increasing the intelligibility of the claims and, consequently, such reference marks have no limiting effect on the interpretation of each element identified by way of example by such reference marks.