EP2373402A1

EP2373402A1 - Air purifying system and method associated thereto

Info

Publication number: EP2373402A1
Application number: EP09806044A
Authority: EP
Inventors: Giuseppe Molinari; Filiberto Silvagni; Claudio Molinari
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-12-23
Filing date: 2009-12-22
Publication date: 2011-10-12
Also published as: ITMI20082306A1; WO2010073217A1; IT1392486B1

Abstract

A system (IM) for purifying air in an indoor environment (A), with subsequent total or partial recirculation or ejection outside, comprising aspirating means (B) adapted to generate a flow (F) of air circulating along a path (P) defined by conveying means (C;C1,C2,C3), and purifying means (S;2, 3,4,5, 6,7, 10) of said air, arranged along said path (P); the mentioned purifying means (S;2, 3,4,5,6,7, 10) comprise at least one scrubbing unit (4) of said air by passing said flow (F) through a liquid with controlled pH and added ozone, and a unit (6) for generating and feeding said ozone to said scrubbing unit (4).

Description

AIR PURIFYING SYSTEM AND METHOD ASSOCIATED THERETO

Field of the invention

The present invention relates to a system for purifying air from odors and polluting elements, and to a method associated thereto.

In particular, the present invention is advantageously applied in air purifying treatments in working environments with a high concentration of polluting gases and odors, such as, for example, industrial working areas or zones dedicated to cook food in kitchens of hotels, restaurants, bars and the like, and in air conditioning systems to which explicit reference will be made in the following description without therefore loosing in generality. Background art

In general, there are many working environments in which the concentration of fumes and odors or polluting substances is high and for this reason it is absolutely mandatory by law to purify the air in order to allow operators to continue their working activities in safe, healthy conditions and to expel the least possible amount of polluting substances outside.

The currently known methods for purifying air in working environments with high concentrations of polluting substances generally include aspirating the air from these zones, by means of appropriate aspirating hoods or similar means, subjecting the aspirated air to known cleaning processes, which in many cases also include using water scrubbers, activated carbon, and mechanical filters, and diffusing such an aspirated, partially cleaned air outside. These methods have many major drawbacks.

Indeed, the mentioned air cleaning processes are often not perfectly effective, i.e. not capable of purifying the air present in the environments with high concentrations of polluting substances, such as, for example, the kitchens of hotels, restaurants, bars and the like, in food processing industries and air conditioning systems, in which cooking fumes or odorous vapors are dispersed, which are extremely dangerous for humans because the foul air contains harmful gases, such as carbon monoxide CO and carbon dioxide CO₂, nitrogen oxide NOx, or fine dusts PM10, PM2,5, PM1, or VOC (volatile organic compounds) resulting from the cooking of food or from polluted air.

Furthermore, the air thus aspirated and not effectively purified is diffused outside, with the consequence of considerably polluting the outside areas and spaces surrounding the aforesaid environments, with the introduction of highly harmful factors and elements into the outside environment, which with all the emitted pollutant, contribute to make such polluting substances available as a fuel for generating anthropogenic ozone, acid rain and many other potential hazards for human health. Summary of the invention It is the object of the present invention to overcome the severe drawbacks described above.

In particular, it is an object of the present invention to implement a system capable of ensuring the full respect of the current safety laws, and in particular in adherence to the new Lisbon Treaty, by effectively and optimally purifying the air in working environments.

Another object of the present invention is to provide a system which is able to ensure the effective application of antipollution laws even in outdoor zones surrounding the mentioned working environments which are to be subjected to air purifying cycles. A further object of the present invention is to provide a method of air purification and treatment capable of allowing very effective cleaning of the air in working environments, thus obtaining an air so purified to allow the total or partial recirculation thereof in the environment, establishing a virtuous ecological cycle and saving energy, without causing the pollution of the outdoor zones close to said environments. It is worth noting that the recirculation air for compensating the environments in which air aspiration or renewal occurs, is currently taken from the outside, where known data (Aφa~ER data) indicate a polluting hazard in many cases much higher than that of the indoor environment. Brief description of the drawings The technical features of the invention according to the aforesaid purposes are clearly inferable from the content of the following claims and the its advantages will be more apparent from the following detailed description made with reference to the accompanying drawings which diagrammatically illustrate a preferred, but not limitative embodiment of the described system, in which:

- figure 1 is a partial sectional front view with some parts removed from clarity and other parts enlarged and therefore shown with a dashed line, of a first embodiment of the described purifying system;

- figure 2 is a partial sectional front view with some parts removed from clarity and other parts enlarged and therefore shown with a dashed line, of a second embodiment of the described purifying system;

- figure 3 is a diagrammatic, enlarged-scale view of a constructional detail of the system in figure 1 ;

- figure 4 is a diagrammatic, enlarged-scale view of another constructional detail of the system in figure 1 ;

- figure 4A is an enlarged view of the detail in figure 4;

- figure 5 is a diagrammatic view of a variant of the detail in figure 4; and - figure 5A shows a detail of the variant in figure 5 on an enlarged scale.

Detailed description of the invention

With reference to figures 1 and 2, IM indicates as a whole an air purifying system in an closed indoor environment A, in particular a working environment, e.g. an industrial working area. The system IM, according to preferred but not limitative variants in figures 1 and 2, comprises a plurality S of operating units adapted to the purifying treatment of an air flow F generated within a system C of pipes aspirating the polluted air from the environment A by known aspirating means B, e.g. of the fan type; in particular, the operating units are arranged in sequence along the forward movement path P of the aspirated air flow F circulating in the system of pipes C. Electrically motorized air lock means 1 are provided along the pipes in various points thereof, in order to adjust the air amount or delivery of the flow F in the system C. As shown in figures 1 and 2, the path P of the air flow F and thus the system of pipes C, i.e. from pipe C1 to pipe C3, depart from A and advantageously ends in A itself, as better described below.

As shown in figures 1 and 3, the plurality of units S comprises, in sequence along the path P: - a unit 2 for blowing airborne ozone into the polluted air being aspirated;

- a unit 3 for atomizing and scrubbing the polluted air being aspirated with a liquid, preferably water, blown with ozone;

- a unit 4 for scrubbing the polluted air taken from A, with a liquid, preferably water, at controlled pH and blown with ozone;

- a unit 5 for purifying by means of activated carbon filters and residue ozone catalyzation of the air in F let out from the unit 4;

- a unit 6 for generating ozone fed under pressure to the mentioned units 2,3,4, and furthermore a clean-air reintegration unit 7, and also ozone diffusion means 10, as explained in greater detail below, along specific channeling tubes T connected to the units 4,7,10 themselves.

The unit 7 for introducing or reintegrating clean air drawn from the outside into the system of pipes C includes further aspirating means B1 arranged along a pipe C2, is arranged downstream of unit 6, and is preferably connected to unit 6 by means of appropriate tubes so that the air introduced from the outside is advantageously blown with ozone at pipe C2 (see figure 1); furthermore, unit 7 is provided with filtering means 7a, e.g. of the activated carbon type, to define a catalyzing barrier for the photochemically-formed, anthropogenic ozone in addition to other gaseous pollutants and/or odorous organic molecules, and/or HEPA type filters for thin dusts, and preferably also an air heating battery 7b where the air taken from the outside needs to be heated. The heat is exchanged between battery of the ejection channel by holding the ejected air heat and exchanging this heat with the battery present in the unit 7 by treating the outside air being introduced. As shown in figures 1 and 3, the airborne ozone blowing unit 2 is adapted to perform the first cleaning treatment on the polluting substances present in the flow F of air taken from A by means of an introduction in the flow F directly into the system of pipes C, specifically at the point of pipe Cl

As shown in figures 1 and 3, the unit 3 for water scrubbing the air in the aspiration channel with water blown with ozone and recirculated by means of a pump from the unit 4 is adapted to continue cleaning the polluting substances suspended in the flow F of air taken from A. As shown in figures 1 and 3, the air scrubbing unit 4 is adapted to abate the polluting substances, such as solid and gaseous fractions, e.g. CO, CO₂, NOx₁ VOC, PM10, PM2,5, PM1, aldehydes, etc., suspended in the flow F of air taken from A by introducing ozonized water, i.e. blown with ozone generated by unit 6, in the flow F directly into the system of pipes C, specifically at the point of pipe C1 , indicated by reference numeral 3' in figure 1 , in order to capture the mentioned residual polluting substances, and then by precipitating said polluting substances into a decantation tank 13 or "washing bed" containing water; a device for keeping a predetermined pH is provided and connected to an automatic dispenser which aspirates a product needed for keeping the predetermined values. Thereby, the flow of polluted air is subjected to a complete scrubbing action with ozonized water having a predetermined degree of pH acidity, thus determining an oxidizing purification which destroys the polluting substances, with the further advantage of a deodorizing effect. Unit 4 thus comprises: - a container 4 of the fluid bed type, the bottom of which defines the mentioned decantation tank 13,

- a covering dome-like member 15 arranged over an end part t of pipe C1 protruding over the level of ozonized water arranged in tank 13; such a domelike member 15 with concavity facing downwards and partially immersed into the water bed is adapted to promote a downward oriented diffusion of the air already pre-treated by units 2 and 3, atomized with ozonized water (arrows f in figure 3) so as to favor its scrubbing by precipitation and dissolution of polluting substances in the tank 13 underneath,

- a partition 16 arranged at the top of container 4 over the mentioned member 15 and adapted to define a filter for separating drops of water from the air in the flow F,

- a diffuser 17 of ozone blown in water arranged at the bottom of tank 13,

- a water feeding network pipe for filling the tank 13 itself, including specific activated carbon filters 19, - and pump means 20 for drawing ozonized water to be fed to point 3 of pipe C1 for obtaining the mentioned atomization directly along and inside the same pipe C1. Tank 13 further comprises a sensor 21 adapted to measure the pH degree of acidity of water, connected to an automatic dispenser which draws a chemical product for keeping the predetermined values, and an overflow 22 for keeping the water level in tank 13. As shown in figures 1 , 4 and 4A, the ozone generating unit 6 comprises at least one tube 23 made of dielectric material, arranged in an appropriate closed container 24, in which air from the outside is adapted to circulate by means of grids 25 which feed the air to generate ozone. Tube 23 is provided with a first electrically connected, cylindrical net 26 arranged coaxially inside the tube 23 itself, and a second electrically connected, cylindrical net 27 arranged coaxially outside the tube 23 itself, so as to determine a "double crown effect" (figure 4A).

Such a double crown effect generates a correct amount of ozone, optimal for obtaining a purifying effect of air, because an air flow interacts with the electric field generated both inside and outside the tube 23.

In the alternative variant shown in figure 5, the tube 23 and the two nets 26 and 27, coaxial to unit 6, are replaced by a generator 30 formed by two equivalent, opposite plates 31 and 32, each of which is provided with a plurality of ends 33 having tips 34, three tips 34 as shown in the detail in figure 5a. Plates 31 and 32 define two positive electrodes between which a foil-like member 35, adapted to define the negative electrode, is arranged. The "double crown effect' is thus obtained by means of such a generator 30 having a double plate or a "bed of nails". In particular, the optimal amount of ozone produced is then advantageously fed and channeled to the mentioned units 2 and 4 by pressurized pump means PP without using compressed air as conveying element. The container 24 is further provided with an ozone collecting compartment 24a.

Unit 6 is further connected by means of channeling tubes 28 to an ozone diffusing device, indicated by numeral 10 as a whole in figure 1 , and provided with diffusers 10a for diffusing correct, allowed amounts of ozone into environment A and surroundings, as a further service of deodorizing, hygienizing and sanitizing the treated environments. Sensor means 9 is provided to check that the amount of ozone introduced in A with the recirculated air is within the strictly allowed parameters provided by law. Otherwise, if such a parameter is exceeded, the internal recirculation with the cleaned air is immediately stopped and the air is either totally or partially ejected and the recirculation is totally or partially carried out by using an external withdrawal.

Finally, the system IM includes actuating and control means 8, adapted to control and actuate the operation of the whole system IM, and thus in particular of the mentioned units 2, 3, 4, 5, 6 and 7, and also the operation of the air lock 1 , which adjusts the flow rate in the system of pipes C, and of sensor 9; the system IM is further provided with a module 12, provided on a further pipe C4 connected to the aspirating means B and adapted to recover heat.

The system IM, the operation of which follows an operating method which is easily inferable from the description of the above-described units of the series S, thus substantially aspirates the flow F of polluted air from A along the path P, blows airborne ozone into it, then atomizes it with ozonized water, and then subsequently carries out purifying scrubbing and decantation thereof (unit 4), followed by filtering by means of activated carbon (unit 5) and a possible mixing with clean, purified air drawn from the outside (unit 7), to completely re-introducing it into the same environment A, either totally or in part. The air re-introduced in A after the purifying and cleaning treatment by means of the system IM is thus effectively purified from polluting substances, and thus perfectly healthy and breathable, of substantially better quality than outside air, thus making the indoor environment A healthy and pleasant. As it may be inferred from the above description and the accompanying drawings, there are no leakages of polluting air outside, but of treated air only, the zones outside the environment A are not polluted with a great advantage in terms of environmental safety.

According to a preferred embodiment with the variant illustrated in figure 2, the environment A is specifically a restaurant kitchen, industrial plants or the like, i.e. an environment where the polluting substances are mainly those deriving from cooking operations, air conditioning operations or similar treatments. Therefore, only a further system of aspirating, filtering hoods 30 is advantageously added to the system IM well described above with reference to figure 1 , applied close to and over the kitchen appliances, e.g. the cooking range 31 intended for cooking food or an oven 32.

These hoods 30 are particularly connected to the system of pipes C, at pipe C1 and pipe C3, which in such a configuration are further and variably connected to each other, thus defining an optimal continuous recirculation of cleaned air. Furthermore, ozone diffusers 10a are advantageously provided also in adjacent rooms A1 used as pantries or similar storage areas in addition to the working environments themselves, in which the mentioned means 8 for the programmed actuation in the absence of personnel may be arranged, as shown in the configuration of the system IM in figure 2.

The invention thus devised is susceptible to a number of changes and variants all within the scope of the described inventive concept; furthermore, all details may be replaced by other technically equivalent elements.

Claims

1. A system (IM) for purifying air in an indoor environment (A), comprising aspirating means (B) adapted to generate a flow (F) of air circulating along a path (P) defined by conveying means (C;C1 ,C2,C3), and purifying means (3!2,3,4,5,6,7,1O) for said air arranged along said path (P), the system being characterized in that said purifying means (S;2, 3,4,5,6,7, 10) comprise at least one scrubbing unit (4) for said air by passing said flow (F) through a liquid with added ozone and a unit (6) for generating and feeding said ozone to said scrubbing unit (4).

2. A system according to claim 1 , characterized in that it further comprises a unit (2) for diffusing ozone in one of said conveying means (C1) arranged upstream of said scrubbing unit (4).

3. A system according to claim 1 or 2, characterized in that it further comprises a unit ⁽J) for aspirating the air from outside said environment (A), said aspirating unit (7) being adapted to introduce cleaned air into said flow (F) downstream of said scrubbing unit (4).

4. A system according to claim 3, characterized in that said aspirating unit (7) is connected to said ozone generating unit (6) for introducing air with added ozone into said flow (F).

5. A system according to claim 3 or 4, characterized in that said aspirating unit (7) comprises means (7a) fo filtering said air aspirated from the outside.

6. A system according to one of the claims from 3 to 5, characterized in that said aspirating unit (7) comprises means (7b) for heating the air which is not recirculated and ejected outside, and the air aspirated from the outside for possible air reintegration.

7. A system according to one of the preceding claims from 1 to 6, characterized in that it further comprises a filtering unit (5) of said air to filter said air downstream of said scrubbing unit (4) along said path (P) of said flow (F).

8. A system according to one of the preceding claims from 1 to 7, characterized in that said path (P) of said air flow (F) starts and ends in said indoor environment

(A).

9. A system according to any one of the claims from 1 to 8, characterized in that said scrubbing unit (4) comprises a container (14), the bottom of which is adapted to define a decantation tank (13) for the polluting substances present in said air; a dome-like element (15) adapted to promote the diffusion towards said bottom of said container (14) with precipitation of said polluting substances into said tank (13); filtering means (16) of said air, arranged outside said dome-like element (15) and within said container (14); pump means (3, 18,20) for feeding and atomizing the liquid in said tank (13), said pump means (18,20) being connected to said ozone generating unit (6) for diffusing ozonized liquid onto the bottom of said tank (13); and means (17) for diffusing ozone onto the bottom of said tank (13), said diffuser means (17) being connected to said ozone generating unit (6).

10. A system according to claim 9, characterized in that said feeding and atomizing pump means (3,18,20) further comprise means for channeling said ozonized liquid directly into a pipe (3',C1) arranged immediately upstream of said scrubbing unit (4) and connected to said tank (13).

11. A system according to claim 9 or 10, characterized in that said tank (13) further comprises sensor means (21) adapted to measure the degree of acidity or PH of said ozonized liquid, and sensor means (22) for keeping the level of ozonized liquid in the tank (13) itself.

12. A system according to any one of the claims from 1 to 11 , characterized in that said ozone generating unit (6) comprises at least one tube (23) made of dielectric material, arranged in an appropriate closed container (24), within which the air from the outside is adapted to circulate by means of grids (25); said tube (23) being provided with a first electrically connected, cylindrical net (26) coaxially arranged inside the tube (23) itself, and a second electrically connected, cylindrical net (27) coaxially arranged outside said tube (23).

13. A system according to any one of the claims from 1 to 11 , characterized in that said ozone generating unit (6) comprises a generator (30) consisting of two equal and opposite plates (31 ,32), each of which is provided with a plurality of ends (33) having tips (34), said plates (31 ,32) being adapted to define two positive electrodes between which a foil-like element (35) adapted to define the negative electrode is arranged.

14. A system according to any one of the claims from 1 to 13, characterized in that it further comprises membrane-type means (PP, 10, 10a) for feeding and diffusing under pressure, connected to said ozone generating unit (6) for diffusing controlled amounts of ozone into said environment (A); sensor means (9) adapted to detect the correct concentration of ozone in said environment (A), said sensor means (9) being connected to means (8) for actuating and controlling said purifying means (S;2,3,4,5,6,7,10) of said system (IM).

15. A system according to any one of the claims from 1 to 14, characterized in that it further comprises a module (12) adapted to recover heat and connected to said conveying means (C;C4).

16. A system according to any one of the claims from 1 to 15, characterized in that it comprises further means (30) having aspirating hoods applied to said conveying means (C;C1 ,C2,C3).

17. An method of purifying air, comprising the steps of aspirating air from an indoor environment (A) for generating a flow (F) of air moving forward along a path (P), and purifying said air along said path (P); the method being characterized in that said step of purifying comprises at least one step of scrubbing said air with a liquid with added ozone along said path (P).

18. A method according to claim 17, characterized in that said step of purifying further comprises a step of introducing ozone into said flow (F) before said scrubbing.

19. A method according to claim 17 or 18, characterized in that said step of purifying further comprises a step of introducing liquid with added ozone into said flow (F) before said scrubbing.

20. A method according to any one of the claims from 17 to 19, characterized in that said step of purifying further comprises a step of aspirating air from the outside of said environment (A) for introducing it into said flow (F).

21. A method according to claim 20, characterized in that said step of introducing air from the outside into said flow (F) comprises the step of adding ozone to said air.

22. A method according to one of the claims from 17 to 21 , characterized in that said step of scrubbing further comprises an operation of filtering said air.

23. A method according to one of the claims from 17 to 22, characterized in that said air flow (F) starts and ends in said indoor environment (A).

24. A method according to one of the claims from 17 to 23, characterized in that said step of scrubbing comprises, in sequence, the steps of atomizing liquid blown with ozone into said air, channeling said air with ozonized liquid along a path (f) extending through a decantation tank (13) for polluting substances; filtering said air from possible drops of residual liquid; and further filtering said air flow (F).

25. A method according to claim 24, characterized in that said step of scrubbing further comprises measuring the degree of acidity or pH of said ozonized liquid.