CH718170A2 - Air purifying device with cooling means. - Google Patents

Abstract

The invention relates to a mobile plasma air purification device (1) organized in such a way as to treat aerosol particles present within an air flow passing through said device; which device comprises in particular an ionizer (2) connected to the power source and which is positioned so as to receive the flow of air and at least one cooling means (5) which is positioned so as to receive the flow of air upstream of the ionizer.

Description

Field of invention:

The present invention belongs to the field of air purification, and relates more particularly to a mobile air purification device comprising a cooling means, a method of purifying and cooling the air, as well as use of a mobile device for air purification and cooling.

Prior art

[0002] Many activities, in particular medical activities, require an environment with air that is free of pathogens and particles. This is the case of surgical procedures, which take place in operating theaters where the air quality is closely monitored, or even hospitalizations of immunocompromised patients which take place in sterile rooms. It is known from the prior art of devices allowing the purification of air, for example by using plasma cells with corona effect, as described in the patent application FR 3065615. Now, the guarantee of a quality of the Optimal air is not compatible with the use of air conditioners to cool the air. During the summer season, and in particular during heat waves, the devices of the prior art do not make it possible to produce a purified atmosphere having a comfortable temperature for the patients or the other users. On the other hand, maintaining a temperate atmosphere may prove necessary in a hospital setting. This is the case, for example, in operating theatres, where the temperature must be kept below 26°C (standard NFS 90-351). If hospital structures include centralized cooling systems, these are fixed and generally limited to certain technical platforms. The creation of new rooms with a purified and refreshed atmosphere within an existing structure is therefore not easy on the technical level and can prove to be expensive.

[0003] Thus, it is necessary to develop mobile devices allowing not only the purification of the air, but also its cooling.

Disclosure of Invention

[0004] The inventors have developed a mobile air purification device incorporating a cooling means, making it possible to overcome the difficulties set out above.

Thus, a first object of the invention relates to a mobile plasma air purification device organized so as to treat aerosol particles present within an air flow passing through said device; which device comprises: at least one electrical power source; at least one ionizer connected to the power source and which is positioned to receive the airflow; at least one filter, preferably electrostatic, located downstream of the ionizer; at least one air overpressure means to allow the establishment of the air flow within the device; characterized in that said device further comprises: at least one cooling means which is positioned so as to receive the air flow, preferably said cooling means is positioned upstream of the ionizer; at least two temperature sensors arranged respectively upstream and downstream of the cooling means, which two temperature sensors are positioned so as to determine the temperature of the air flow entering and leaving the cooling means respectively; and at least one microcontroller which makes it possible to regulate, as a function of the temperature values measured upstream and downstream of the cooling means, the at least one cooling means so as to obtain the desired temperature value for the air flow in device output.

According to a first particular embodiment, the cooling means of a device according to the invention is a cold unit.

According to a second particular embodiment, the cooling means of a device according to the invention is an air/water exchanger connected to an external cold water circuit, which cooling means incorporates a water inlet and a water outlet allowing the air/water exchanger to be connected to an external cold water circuit, preferably chilled water.

Advantageously, the cooling means further comprises a condensate pan, which is preferably associated with a level sensor and a condensate pump allowing it to be emptied.

[0009] Advantageously, such devices according to the invention further comprise at least one user interface, which preferably allows the user to select the desired temperature value for the air flow at the outlet of the device.

According to a particular embodiment, the device according to the invention further comprises at least one filter upstream of the ionizer.

Advantageously, the device according to the invention further comprises at least one catalyst downstream of the ionizer, which catalyst allows the decomposition of ozone.

[0012] Particularly advantageously, the at least one cooling means is present within a removable drawer within said device.

A second object of the invention relates to a process for purifying and cooling the air of a volume characterized in that it comprises at least the following steps: a. Connection of a device according to the invention to said volume and b. Start-up of said device with a view to blowing purified and cooled air within said volume.

Finally, a third object of the invention relates to a use of a device according to the invention for the purification and cooling of a volume of air.

Description of figures

[0015] Figure 1 schematically shows a device in which the cooling means is an air / water exchanger connected to an external cold water circuit.

[0016] Figure 2 shows a device in which the cooling means is a cold unit.

detailed description

According to a first aspect, the invention relates to a mobile plasma air purification device 1 organized so as to treat aerosol particles present within an air flow passing through said device.

Advantageously, the device 1 according to the invention is intended for air purification. By „air purification“, we mean obtaining a good quality ambient air. The good quality of ambient air can be assessed on the basis of various parameters, and for example the concentration of volatile organic compounds (VOC), the concentration of fine particles, such as the concentration of fine particles whose diameter is less than 10 µm (PM 10), and/or the concentration of fine particles whose diameter is less than 5 µm and/or the concentration of fine particles whose diameter is less than 2.5 µm (PM 2.5), and /or the concentration of fine particles whose diameter is less than 1 µm, and/or the concentration of fine particles whose diameter is less than 0.5 µm, etc.

Such a device 1 comprises in known manner at least one electric power source chosen so as to be able to deliver sufficient power to allow the operation of all of these components, as well as a sufficient voltage to allow the ionizer to generate a plasma.

The device 1 according to the invention also comprises an ionizer 2, connected to the power source, and positioned so as to receive the air flow F.

[0021] Preferably, such an ionizer 2 included in a device 1 according to the invention can take the form of at least one corona-effect plasma cell comprising a polarized electrode substantially in the shape of a needle and a ground electrode, arranged opposite the polarized electrode, comprising a cylinder substantially centered on the polarized electrode and a substantially planar porous film perpendicular to the polarized electrode. Such an ionizer 2 is thus able to generate a plasma that the air flow would pass through, which made it possible to electrically charge the particles present in the air so that they are retained in at least one electrostatic filter. Such an ionizer 2 is well known to those skilled in the art. By way of example, such an ionizer is described in French patent FR 3065615.

The device 1 according to the invention comprises a filter 3, preferably electrostatic, located downstream of the ionizer 2, which filter 3 can be made of mineral material such as glass or ceramic, and particularly preferably fiberglass. Advantageously, such a filter 3, through which the air flow F passes, is capable of retaining the particles charged by the ionizer 2.

The device according to the invention also comprises an air overpressure means 4 to allow the establishment of the air flow F within the device 1. By "setting up the air flow within the device “means the suction of the air to be purified, its flow through the various elements of the device 1, such as the ionizer 2, the various filters 3, 9, and the cooling means 5, as well as its evacuation to the outside of the device 1. Advantageously, such a means of putting the air under pressure 4 can take the form of a fan or a turbine. Preferably, such an air overpressure means 4 is a turbine. Such an air overpressure means 4 is advantageously connected to the electrical power source. Preferably, the air overpressure means 4 will allow the recovery, circulation, and blowing of the air at a flow rate of between 100 and 1700 m<3>/h. Even more preferably, the air overpressure means 4 will not allow the recovery, circulation and blowing of air at a flow rate greater than 1700 m<3>/h, in order to limit the risks condensate entrainment in the air circuit.

According to a particular embodiment, the device according to the invention 1 further comprises at least one filter 9 upstream of the ionizer 2. Preferably, said at least one filter 9 upstream of the ionizer 2 is a filter of the mechanical type, able to allow the entry of air into the device 1 according to the invention while retaining large particles. Such at least one filter 9 upstream of the ionizer 2 may consist of a flexible alveolar material of the foam type, for example polyether, or else a fabric.

According to another particular embodiment, the device according to the invention 1 further comprises at least one catalyst 10 downstream of the ionizer 2, which catalyst 10 allows the decomposition of ozone. Indeed, ionizers comprising plasma cells generate ozone, whose oxidizing power makes it possible to improve the elimination of residual pollutants after passing through the plasma cell. Now, the ozone generated by the ionizer 2 must be eliminated from the air flow before it leaves the device of the invention 1, which advantageously allows the catalyst 10 included in the device according to the invention 1. Such a catalyst 10 can be selected from activated carbon, zeolite or manganese oxide (Mn02), which are capable of allowing rapid decomposition of ozone and nitrogen oxides at room temperature. Such a catalyst 10 preferably takes the form of a honeycomb substrate, for example aluminum, which is coated with manganese oxide. Advantageously, such a honeycomb substrate should have a thickness of at least 10 mm to be sufficiently effective in neutralizing ozone.

Particularly advantageously, the device according to the invention 1 comprises at least one cooling means 5, capable of allowing the cooling of the air flow F to a desired temperature. The cooling means 5 is positioned so as to receive the air flow F upstream of the ionizer 2.

According to a first particular embodiment, the cooling means 5.5′ of a device according to the invention is a cold unit 5. The term “cold unit” or refrigerating unit means a mechanical device allowing the production cooling by involving a thermodynamic cycle based on the compression and expansion of a refrigerant as well as the evacuation of calories in a heat exchanger (plate condenser).

[0028] In detail, a refrigeration unit of a device according to the invention may comprise a refrigeration circuit comprising an evaporator capable of ensuring the transfer of calories from the air flow to be cooled to the refrigerant, a compressor capable of ensuring the compression of the refrigerant and its discharge to the condenser, a condenser allowing the transfer of heat from the refrigerant to a secondary circuit and an expansion valve capable of injecting the refrigerant into the evaporator. Typically, the chiller can take the form of an air/water heat pump incorporating a variable power compressor. According to a preferred embodiment, the secondary circuit, allowing the evacuation of the calories of the refrigerant fluid out of the system, is a water circuit, said water comes from the sanitary water network, and is discharged into the drain.

[0029] Such a secondary circuit advantageously comprises a pressostatic valve making it possible to adjust the circuit water flow to the condensation pressure, thus limiting the water consumption of the device to what is strictly necessary. Thus, the water flow of the secondary circuit varies according to the power of the compressor. By way of example, the water consumption of the secondary circuit of a refrigeration unit of a device according to the invention will be 60 1/h for a compressor power of 0.5 kW, 1001/h for a power of 0.9 kW, 1601/h for a power of 1.4 kW. Alternatively, the secondary circuit can be connected to a chilled water circuit connected to a “waterchiller” type cooling unit.

Finally, the refrigeration circuit of a refrigeration unit 5 of a device according to the invention 1 can also include any type of sensor making it possible to monitor various parameters such as the pressure or the temperature of the refrigerant.

Such a configuration advantageously allows the use of the mobile device 1 according to the invention without the latter necessarily being connected to a chilled water network, thus limiting installation costs.

According to a second particular embodiment, the cooling means of a device according to the invention is an air/water exchanger 5' connected to an external cold water circuit 7, which cooling means incorporates an inlet of 'water and a water outlet for connecting the air / water exchanger 5' to an external cold water circuit 7, preferably chilled water. The term "air/water exchanger" means any heat exchanger capable of allowing the cooling of the air flow by allowing the transfer of calories from said air flow to the water of a cold water circuit, preferably of ice water. Such cold water circuits or chilled water networks are commonly present in hospitals. By way of example, the temperature of the water present in such cold water circuits can be between 5 and 10°C. Advantageously, said air/water exchanger 5' is connected to the cold water circuit 7 by a loop comprising a regulating valve 11 capable of regulating the flow of cold water passing through the exchanger. The flow of cold water passing through the exchanger will depend on the desired cooling capacity. For example, a flow of cold water (7°C) of 300 1/h will provide a cooling capacity of 1.5 kW, a flow of 500 1/h will provide a cooling capacity of 2.2 kW, a flow rate of 800 1/h will provide a cooling capacity of 3.9 kW and a flow rate of 1200 1/h will provide a power of 1200 1/h.

Such a configuration advantageously makes it possible to limit the sound level during operation of the device according to the invention 1, compared to a configuration with cold unit 5. In addition, such a configuration makes it possible to reduce the intrinsic electrical consumption of the device according to invention 1 during its operation.

The cooling means 5 of a device according to the invention 1 further comprises a condensate pan 8. Such a condensate pan 8 is capable of recovering the condensation water produced during the cooling of the air by the evaporator, the air/water exchanger, or the condenser depending on the configuration of the cooling means 5. Preferably, the condensate pan 8 is made of stainless steel.

Advantageously, the condensate pan 8 of a cooling means 5 of a device according to the invention 1 is associated with a level sensor and a condensate pump 8' allowing it to be emptied. By way of example, such a level sensor can be an optical sensor, capable of triggering the emptying of the condensate tray by the condensate pump. The condensates are preferably discharged into the waste water network. Such emptying advantageously makes it possible to limit the health risks represented by the stagnation of water in the condensate pan 8.

A device according to the invention 1 further comprises at least two temperature sensors 6, 6 'arranged relatively upstream and downstream of the cooling means 5. Advantageously, the at least two temperature sensors 6,6' are positioned so as to determine the temperature of the air flow F at the inlet and at the outlet of the cooling means 5, 5'.

A device according to the invention 1 also comprises at least one microcontroller or central processing unit. Such at least one microcontroller of a device according to the invention 1 is advantageously connected to all of the electronic elements of the device 1, in particular to the temperature sensors 6,6' arranged upstream and downstream of the cooling means 5, 5', to at least one cooling means 5, 5' and to at least one ionizer 2. Such at least one microcontroller of a device according to the invention 1 makes it possible to regulate the at least one means cooling 5, 5 'according to the temperature values measured upstream (return temperature) and downstream (blowing temperature) thereof, so as to obtain the desired temperature value (setpoint temperature) for the flow of air F at the outlet of device 1.

In detail, the microcontroller will calculate the difference between the recovery temperature measured upstream of the cooling means and the setpoint temperature, then will control (or not) the operation of the cooling means 5.5'. The operating parameters of the cooling means 5.5' may vary according to said temperature difference calculated by the microcontroller.

For example, the microcontroller may, if the at least one cooling means is a cold unit 5, control the speed of the compressor, depending on the thermal load and the setpoint temperature, so as to obtain a temperature of the air flow downstream of the cooling means (blowing temperature) substantially equal to the setpoint temperature. The speed of the compressor may vary, for example, from 12 to 90 rotations per second.

Still by way of example, the microcontroller may, if the at least one cooling means is an air/water exchanger 5' connected to a cold water circuit 7, control the flow of cold water in said exchanger air/water 5', depending on the characteristics of the cold water circuit and the set temperature, so as to obtain a temperature of the air flow downstream of the cooling means (blowing temperature) substantially equal to the set temperature . The flow rate of cold water in the air/water exchanger may vary, for example, from 200 to 1500 1/h.

Advantageously, the device according to invention 1 will further comprise at least one user interface preferably taking the form of a touch screen, and connected to the microcontroller. Such a user interface allows the user to visually monitor the operating parameters of the device according to the invention. By way of example, the user interface may display the flow of air treated by the device according to the invention 1, an operating indicator of the cooling means 5.5', the return temperature measured upstream of the means of cooling 5.5', the setpoint temperature sought at the output of device 1. Advantageously, the user interface of a device according to the invention 1 allows the user to configure the operating parameters of device 1, by the through the touch screen, or navigation buttons. For example, the user interface may allow the user to set the desired temperature for the air flow F at the device outlet and the air flow treated by the device 1.

According to a particular embodiment, the cooling means 5.5 'of a device according to the invention 1 is advantageously included in a removable drawer 12. By removable drawer is meant a locker that can be racked in a compartment of the device according to the invention 1. Such a removable drawer 12 advantageously facilitates access to and removal of the cooling means 5.5' to allow its maintenance, for example.

[0043] According to a second aspect, the invention relates to a process for purifying and cooling the air of a volume, characterized in that it comprises at least the following steps: a. Connection of a device according to the invention 1 to said volume and b. Start-up of said device 1 with a view to blowing purified and cooled air within said volume.

Purification process according to the invention means a process suitable for obtaining good quality ambient air. The good quality of ambient air can be assessed on the basis of various parameters, and for example the concentration of volatile organic compounds (VOC), the concentration of fine particles, such as the concentration of fine particles whose diameter is less than 10 µm (PM 10) and/or the concentration of fine particles whose diameter is less than 2.5 µm (PM 2.5), etc.

The term cooling method according to the invention means a method capable of allowing the blowing of air having a temperature below the temperature at which said air was taken up by a device according to the invention.

[0046] By way of example, a volume within which the air is purified and cooled by a method according to the invention can be a clean room, a mobile or fixed sterile room, a laboratory room, a block room surgery, etc.

According to a final aspect, the invention relates to a use of a device according to invention 1 for the purification and cooling of a volume of air.

Other advantages of the invention will appear on reading the nonlimiting examples given below.

Examples:

Example 1: Sound level of devices according to the invention: The sound levels of two devices according to the invention (comprising a cold unit or an air/water exchanger connected to a cold water network) are measured according to the standard NF EN ISO 3744 (February 2012), 2 m from the devices.

[0050] The sound level measurements are presented in the following table:

[Table 1]

[0051] Cooling medium Compressor speed (rps) 500 1000 1500 1700 Cooling unit 30 30 34 41 44 60 35 37 42 44 90 45 45 46 49 Cold water network NCO < 30 35 41 43

As shown by the data presented in Table 1, the devices according to the invention have a limited sound emission, guaranteeing comfort for the users (for example patients) remaining close to such devices in operation.

Claims (10)

1. A mobile plasma air purification device (1) organized so as to treat aerosol particles present within an air flow (F) passing through said device; which device comprises: – at least one electrical power source; – at least one ionizer (2) connected to the power source and which is positioned so as to receive the airflow; – at least one filter (3), preferably electrostatic, located downstream of the ionizer (2); - at least one air overpressure means (4) to allow the establishment of the air flow within the device; characterized in that said device (1) further comprises: – at least one cooling means (5.5') which is positioned so as to receive the air flow (F), preferably the at least one cooling means (5.5') is positioned upstream of the ionizer (2); – at least two temperature sensors (6, 6') arranged respectively upstream and downstream of the cooling means (5.5'), which two temperature sensors (6, 6') are positioned so as to determine the temperature the air flow (F) entering and leaving the cooling means (5.5') respectively; and – at least one microcontroller which makes it possible to regulate, according to the temperature values measured upstream and downstream of the cooling means (5), the at least one cooling means (5) so as to obtain the desired temperature value for the air flow (F) leaving the device. 2. The device according to claim 1, characterized in that the at least one cooling means (5.5 ') is a cold unit (5). 3. The device according to claim 1, characterized in that the at least one cooling means (5.5 ') is an air / water exchanger (5') connected to an external cold water circuit (7), which cooling means (5') incorporates a water inlet and a water outlet allowing the air/water exchanger to be connected to an external cold water circuit, preferably chilled water. 4. The device (1) according to any one of the preceding claims, characterized in that the cooling means (5) further comprises a condensate tray (8) which is preferably associated with a level sensor and a condensate pump (8') allowing it to be emptied. 5. The device (1) according to any one of the preceding claims, characterized in that it further comprises at least one user interface, which preferably allows the user to select the desired temperature value for the flow of air leaving the device. 6. The device (1) according to any one of the preceding claims, characterized in that it further comprises at least one filter (9) upstream of the ionizer. 7. The device according to any one of the preceding claims, characterized in that it further comprises at least one catalyst downstream of the ionizer, which catalyst allows the decomposition of ozone. 8. The device according to any one of the preceding claims, characterized in that the at least one cooling means is present within a removable drawer within the device. 9. A process for purifying and cooling the air of a volume characterized in that it comprises at least the following steps: has. Connection of a device as defined in one of claims 1 to 8 to said volume and b. Start-up of said device with a view to blowing cooled and purified air into said volume. 10. A use of a device as defined in one of claims 1 to 8 for the purification and cooling of a volume of air.