JP7496294B2 - Air Purifier - Google Patents

Description

The present invention relates to an air purifier that has the functions of sterilization, deodorization, dust removal, and gas removal.

Conventionally, there is an air purifying device as described in Patent Document 1, for example. This device has a housing with an air passage through which the air to be sterilized flows from upstream to downstream, a spray device that sprays slightly acidic electrolyzed water as a disinfectant solution into the air to be sterilized flowing through the air passage, and a circulation tank that receives the disinfectant solution that drops from the air passage. It also has a circulation system that supplies the slightly acidic electrolyzed water from the circulation tank to the spray device, and a chemical supply device that supplies the slightly acidic electrolyzed water to the circulation tank. The chemical supply device has an external extraction section that extracts the slightly acidic electrolyzed water outside the housing.

Patent No. 6223112

Generally, the major factors that affect the sterilization effect of an air purifier are the contact time and frequency between the sterilizing solution and the air to be sterilized.

The wind tunnel is an important component for ensuring this contact time and frequency. Depending on the structure of the wind tunnel, the airflow conditions, such as the airflow speed and airflow direction of the air to be sterilized, and the diffusion state of the sprayed disinfectant solution will vary.

In air purifying devices that use media, ensuring that the water sprayed from the spray nozzle is sufficiently dispersed to wet the entire surface of the media contributes to maximizing the frequency of contact between the disinfectant solution and the air to be disinfected. To achieve this, it is necessary to set the humidification distance, which is the distance from the spray nozzle to the media, as the optimal effective humidification distance, and to appropriately set the flight time of the disinfectant solution sprayed from the spray nozzle to the media. However, optimizing this effective humidification distance and flight time is an obstacle to making the device more compact.

The present invention aims to solve the above problems and provide an air purifier that can sufficiently diffuse the water sprayed from the spray nozzle to wet the entire surface of the media, while also achieving a compact device.

In order to solve the above problems, the air purifying device of the present invention comprises a housing forming a purification air passage through which air to be sterilized flows from an upstream air intake port provided on the front surface of the exterior to an downstream air supply port, a sprayer which sprays a germicide solution into the air to be sterilized flowing through the purification air passage, a medium located upstream of the sprayer in the flow direction of the air to be sterilized and which retains the germicide solution sprayed from the sprayer, and a wind tunnel which forms the purification air passage and contains the medium to form an air-liquid contact area where the air to be sterilized comes into contact with the germicide solution, the wind tunnel extending laterally opposite the air intake port. the ratio W/H of the air tunnel width W, which is the width of the downstream opening along the front-to-rear direction of the housing exterior, to the air intake height H, which is the height of the upstream opening, is in the range of -0.5 to +1.0 with a reference value of 1.0 ; the media is arranged inside the air tunnel at an angle diagonally downward from the upstream opening side toward the rear side of the housing exterior, and the angle of inclination of the downstream opening with respect to the opening plane is in the range of -19° to +18° with a reference value of 45° .

As described above, according to the present invention, in a wind tunnel that forms an airflow path changing region where the airflow path of the air to be sterilized changes from horizontal to upward, and that contains media to form an air-liquid contact region where the air to be sterilized comes into contact with a disinfectant solution, the ratio W/H of the wind tunnel width W of the downstream opening to the air intake height H of the upstream opening is set in the range of -0.5 to +1.0 with a reference value of 1.0, thereby optimizing the flow rate and airflow state of the air to be sterilized passing through the wind tunnel, preventing short-circuiting of the airflow in the wind tunnel and maximizing the residence time of the air to be sterilized.

As a result, the spray of disinfectant solution that is sprayed from above the diagonally positioned media toward the bottom end of the media and flies along the top surface of the media stays in the air for a longer period of time and is sufficiently diffused to wet the entire surface of the media, improving the contact time and frequency between the air to be disinfected and the disinfectant solution, and enabling the device to be made more compact.

In addition, by placing the media at an angle downward in the airflow path change area, the surface area of the media can be increased, increasing the gas-liquid contact area and improving the performance of removing airborne viruses, while also contributing to the efficient use of space within the housing and the miniaturization of the device.

FIG. 1 is an overall perspective view showing an air purifying device according to an embodiment of the present invention; FIG. 2 is a schematic diagram showing the configuration of an air purifying device according to the embodiment; FIG. 2 is a schematic diagram showing the configuration of an electrolytic cell of the air purifying device according to the embodiment; FIG. 2 is a schematic diagram showing a main part of the air purifying device according to the embodiment; FIG. 2 is a schematic diagram showing an air tunnel of the air purifying device according to the embodiment; FIG. 2 is a graph showing the relationship between the aspect ratio of the wind tunnel and the sterilization rate in the air purifying device according to the embodiment. FIG. 2 is a graph showing the relationship between the operation time of the air purifying device according to the embodiment and the number of airborne viruses.

The following describes an embodiment of the present invention with reference to the drawings.

As shown in Figures 1 to 4, the air purifier has an air intake 502 at a lower position and an air outlet 503 at an upper position on a door body 501 on the front exterior of a housing 500, and forms a purification air passage 52 inside the housing 500 through which the air to be sterilized 51 flows from the air intake 502 on the upstream side to the air outlet 503 on the downstream side.

Along the purification air passage 52 of the housing 500, a first dustproof net 504, a dry filter 505, media 506, a spray device 53, an eliminator 507, a fan device 600, and a second dustproof net 508 are provided in this order from upstream to downstream in the flow direction of the air to be sterilized 51.

The first dustproof net 504, dry filter 505, and media 506 are attached to the air tunnel 509 that forms the gas-liquid contact area of the purification air passage 52.

The air tunnel 509 forms the purification air passage 52, and contains the media 506 to form an air-liquid contact area where the air to be sterilized comes into contact with the sterilizing solution. The air tunnel 509 has an upstream opening 701 facing horizontally opposite the air intake 502, and a downstream opening 702 facing upward opposite the eliminator 507, forming an air current change area where the air current of the air to be sterilized changes from horizontal to upward.

As shown in FIG. 5, the ratio W/H of the wind tunnel width W, which is the width of the downstream opening 702 along the front-to-rear direction of the exterior of the housing 500, to the air intake height H, which is the height of the upstream opening 701, of the wind tunnel 509 is in the range of -0.5 to +1.0 with a reference value of 1.0.

The media 506 is located upstream of the spray device 53 in the flow direction of the air 51 to be sterilized, and is arranged inside the wind tunnel 509, inclined diagonally downward from the upstream opening 701 side toward the rear side of the exterior of the housing 500, and the inclination angle θ of the downstream opening 702 with respect to the opening surface 703 corresponds to the ratio W/H to the air intake height H, and is in the range of -19° to +18° with a reference value of 45°. A single media 506 can be arranged, or multiple media 506 can be arranged. When multiple media 506 are arranged, the lower media 56 captures water droplets falling from the upper media 56 to form a water film. The mesh coarseness of the media 56 is made finer than that of the lower mesh 56.

The spray device 53 sprays a bactericide solution, which is slightly acidic electrolytic water, as spray water along the media 506 into the air to be sterilized flowing through the purification air passage 52, and is equipped with multiple spray nozzles 531. The spray nozzles 531 may be arranged facing diagonally downward or upward, and the spray device 53 may also be arranged in a position opposite the media 506.

The slightly acidic electrolyzed water used here is an aqueous solution whose main active ingredient is hypochlorous acid (HClO), with a pH of 5.0-6.5 and an effective chlorine concentration of 10-80 mg/kg.

The media 506 is a mat of conductive material that holds the water sprayed from the spray device 53 and promotes gas-liquid contact between the air to be sterilized and the sterilant solution. The eliminator 507 captures water droplets and mist and removes them from the airflow, and is located above the air tunnel 509 that contains the media 506.

A circulation tank 54 is provided below the media 506, and the circulation tank 54 receives and stores the disinfectant solution that descends from the purification air passage 52. A relay tank 541 is provided inside the circulation tank 54, and a descending liquid guide plate 542 is provided to cover the relay tank 541.

A circulation system 55 is provided between the circulation tank 54 and the spray device 53, and the circulation system 55 has a circulation pump 550 and supplies the disinfectant solution from the circulation tank 54 to the spray device 53.

In the circulation system 55, a circulation pump 550 that both sprays and discharges the disinfectant solution is located below the circulation tank 54, and a three-way flow path switching valve 551 and a check valve 552 are installed downstream of the circulation pump 550. A drainage system 567 branches off from the three-way flow path switching valve 551, and by switching the three-way flow path switching valve 551, one circulation pump 550 can be used for both circulating and discharging the disinfectant solution.

In addition, when the circulation pump 550 is stopped, the check valve 552 prevents the backflow of the disinfectant solution in the circulation system 55. Therefore, if the spray nozzle 531 of the spray device 53 is positioned facing upward, the inside of the circulation system 55 will be filled with disinfectant solution when the circulation pump 550 is stopped, and no abnormal noise caused by air being discharged will be generated when the circulation pump 550 is restarted.

The chemical supply system 56 that supplies the mildly acidic electrolyzed water, which is a disinfectant solution, includes a generator 561 that generates mildly acidic electrolyzed water, a water supply system 562 that supplies water to the generator 561, a dilution water supply system 563 that branches off from the water supply system 562 and supplies dilution water to the circulation tank 54, the relay tank 541 mentioned above, a preparation supply unit 564 that supplies mildly acidic electrolyzed water from the generator 561 to the relay tank 541 and the circulation tank 54 via the relay tank 541 at a large preparation flow rate, and a replenishment supply unit 566 equipped with a relay pump 565 that drips and supplies mildly acidic electrolyzed water from the relay tank 541 to the circulation tank 54 at a small replenishment flow rate.

In this embodiment, the relay tank 541 is placed inside the circulation tank 54, but it can also be placed outside the circulation tank 54.

A three-way flow path switching valve 564b is installed in the dispensing supply unit 564, and the external removal unit 564c is connected to the three-way flow path switching valve 564b via a flow rate adjustment valve 564d. The external removal unit 564c is provided on the front surface of the door body 501 of the housing 500, and can swing up and down between an upper horizontal position where the tip faces horizontally and a lower inclined position where the tip faces downward, and can be tilted at any angle within the angle range (0-90°) set between the horizontal position and the inclined position.

The generator 561 has a solenoid valve 653, a flowmeter 654, and an electrolytic cell 655 in the path from a water supply port (strainer) 651 that communicates with a water supply system 562 to an outlet port 652 that communicates with a drug supply unit 564, and a hydrochloric acid cartridge 657 for the raw drug is connected to the electrolytic cell 655 via a drug pump 656.

As shown in FIG. 3, the electrolytic cell 655 has a water-passing structure with an opening 801 that communicates with the pipeline of the water supply system 562, and an electrode 802 is disposed in the cell. The electrolytic cell 655 electrolyzes the hydrochloric acid of the raw chemical solution supplied to the cell with the electrode 802 to generate chlorine gas G, which is then mixed into the water flowing through the pipeline of the water supply system 562 from the opening 801 of the electrolytic cell 655, to obtain slightly acidic electrolyzed water.

A control device 900 that controls the operation of the air purifier is provided on the front side of the door body 501, and the control device 900 has an operation panel 901 that is a touch panel.

The control device 900 has an air purification operation mode section that supplies the slightly acidic electrolyzed water generated by the generation device 561 to the spray device 53, and a disinfectant water operation mode section that extracts the slightly acidic electrolyzed water generated by the generation device 561 from the external extraction section 564c. Depending on the operation of the three-way flow path switching valve 564b, the control device 900 is set to either the air purification operation mode section or the disinfectant water operation mode section.

The operation of the above-mentioned configuration will now be described.
(Normal operation mode of the air purification operation mode section)
The chemical supply device 56 drips the slightly acidic electrolyzed water from the relay tank 541 to the circulation tank 54 via the replenishment supply unit 566 using the relay pump 565 at a small replenishment flow rate, for example, 0.05 L/min in this case, to maintain the effective chlorine concentration of the sterilant solution in the circulation tank 54 at 0.1-10 mg/L, and keep the sterilant solution in the circulation tank 54 at a dilute concentration suitable for sterilization.

In this state, the sterilant solution in the circulation tank 54 is supplied to the spray device 53 by the circulation pump 550, and the sterilant solution whose concentration has been adjusted in the circulation tank 54 is sprayed from the spray nozzle 531 of the spray device 53 onto the air to be sterilized 51 flowing from the upstream side to the downstream side through the purification air passage 52 of the housing 500.

As a result of this spraying, foreign matter such as airborne bacteria and dust contained in the air to be sterilized 51 collides with the sprayed water of the sterilizing solution, is captured, and sterilized. Furthermore, when the sprayed water of the sterilizing solution reaches the media 506, it carries down the airborne bacteria and dust adhering to the media 506, and also picks up the airborne bacteria, dust, and other foreign matter contained in the air to be sterilized 51, and flows into the circulation tank 54.

At this time, the wind tunnel 509 forms an airflow path changing area where the airflow path of the air to be sterilized 51 changes from horizontal to upward, contains the media 506 and forms an air-liquid contact area where the air to be sterilized 51 comes into contact with the sterilant solution, and the ratio (aspect ratio) W/H of the wind tunnel width W of the downstream opening 702 to the air intake height H of the upstream opening 701 is in the range of -0.5 to +1.0 with a reference value of 1.0, so that the flow rate and airflow state of the air to be sterilized 51 passing through the wind tunnel 509 are optimized, and short-circuiting of the airflow in the wind tunnel 509 is suppressed, maximizing the residence time of the air to be sterilized 51.

As a result, the spray of disinfectant solution that is sprayed from the spray nozzle 531 positioned above the obliquely positioned media 506 toward the bottom end of the media and flies along the top surface of the media stays in the air for a longer period of time and is sufficiently diffused to wet the entire surface of the media 506, improving the contact time and frequency between the air to be sterilized 51 and the disinfectant solution, and enabling the device to be made more compact.

In addition, by placing the media 506 at an angle downward in the air current change area, the space inside the housing can be used more effectively, contributing to the miniaturization of the device.

Dilution water is supplied to the circulation tank 54 from the dilution water supply system 563 as necessary to make up for the amount lost due to spraying. In addition, in the circulation tank 54, slightly acidic electrolyzed water is dripped at a small refilling flow rate to maintain the effective chlorine concentration of the disinfectant solution in the tank of the circulation tank 54 at a concentration suitable for disinfection of 0.1-10 mg/L, so that bacteria flowing into the circulation tank 54 can be disinfected reliably. In addition, by directly spraying the disinfectant solution into the air to be disinfected 51 with high saturation efficiency, foreign matter such as suspended bacteria and dust contained in the air to be disinfected 51 can be taken into the disinfectant solution, and dust removal can be achieved in addition to disinfection.

The sterilized air that has passed through the media 506 passes through an eliminator 507 and is supplied into the room by a fan device 600 .
(Preparation operation mode of air purification operation mode section)
The three-way flow path switching valve 551 is operated, and the old disinfectant solution in the circulation tank 54 is discharged from the system through the discharge system 567 by the circulation pump, thereby lowering the liquid level in the circulation tank 54 .

Next, the three-way flow switching valve 551 is returned to its original position so that the circulation system 55 is connected to the spray device 53. The chemical supply system 56 supplies water from the water supply system 562 to the generator 561, which generates slightly acidic electrolyzed water. The slightly acidic electrolyzed water at the generated concentration is then supplied as a disinfectant solution to the relay tank 541 through the preparation supply section 564 at a large preparation flow rate.

At the same time as supplying the slightly acidic electrolyzed water at the concentration at the time of generation, dilution water is supplied to the circulation tank 54 from the dilution water supply system 563. Then, a new bactericide solution is prepared in batches in the circulation tank 54, consisting of slightly acidic electrolyzed water whose concentration has been adjusted to a set effective chlorine concentration of 0.1-10 mg/L, and the bactericide solution is stored in the circulation tank 54.

At this time, the control device 900 is in operation in the air purification operation mode, and by adjusting the electrolytic current value of the electrolytic cell 655, the amount of chlorine gas generated is controlled to a standard generation amount that corresponds to the standard set value of the effective chlorine concentration.

Furthermore, when the measured water supply rate of the flow meter 654 is less than the standard water supply rate, the control device 900 reduces the amount of chlorine gas generated in proportion to the shortage of water supply, thereby maintaining the effective chlorine concentration of the slightly acidic electrolyzed water generated by the generator 561 at the standard set value, and when the measured water supply rate of the flow meter 654 is more than the standard water supply rate, the control device 900 increases the amount of chlorine gas generated in proportion to the excess of water supply, thereby maintaining the effective chlorine concentration of the slightly acidic electrolyzed water generated by the generator 561 at the standard set value.
(Cleaning operation mode of the air purification operation mode section)
In the cleaning operation mode, the three-way flow path switching valve 551 is operated, the old disinfectant solution in the circulation tank 54 is discharged outside the system through the discharge system 567 by the circulation pump 550, the disinfectant solution is supplied to the circulation tank 54 from the preparation supply section 564, and the circulation tank 54 is filled with a predetermined amount of disinfectant solution to chemically clean the circulation tank 54.
(Operation of the sterilizing water operation mode)
When the slightly acidic electrolyzed water is to be extracted from the air purifier as sterilizing water, the three-way flow switching valve 564b is operated to connect the preparation supply unit 564 to the external extraction unit 564c, and the slightly acidic electrolyzed water is extracted.
Example 1
7 is a graph showing the relationship between the operating time of the air purifier according to this embodiment and the number of airborne viruses (logarithm), and when the air purifier is not operated, the number of airborne viruses (logarithm) in the space to be cleaned is naturally attenuated slightly over time. When the air purifier is operated without spraying a germicide solution, the number of airborne viruses in the space to be cleaned is reduced more than the natural attenuation. When the air purifier is operated by spraying a germicide solution, the number of airborne viruses (logarithm) in the space to be cleaned is reduced by half in 10 minutes, and a sterilization rate of 99% is achieved in the actual number of airborne viruses (actual number).

Figure 6 shows the relationship between the ratio (aspect ratio) W/H of the air tunnel width W of the downstream opening 702 of the air tunnel 509 to the air intake height H of the upstream opening 701, and the time T required to reach a sterilization rate of 99%, in this air purifier, and Table 1 shows data showing the specifications of the air purifier. Here, the condition is that the sum of the air tunnel width W and the air intake height H is constant (fixed).

図６および表１より、到達時間Ｔが１０分以内で除菌率９９％に達する風洞幅Ｗと空気取入高Ｈとの比（縦横比）Ｗ／Ｈは、０．５から２．０の範囲である。縦横比Ｗ／Ｈが１．０である場合には到達時間Ｔが５．７分で除菌率９９％に達し、風洞５０９における除菌対象空気５１の滞留時間τが０．０７４６秒となる。縦横比Ｗ／Ｈが０．５である場合には到達時間Ｔが９．９分で除菌率９９％に達し、風洞５０９における除菌対象空気５１の滞留時間τが０．０６６４秒となる。縦横比Ｗ／Ｈが２．０である場合には到達時間Ｔが９．５分で除菌率９９％に達し、風洞５０９における除菌対象空気５１の滞留時間τが０．０６６４秒となる。

6 and Table 1, the ratio (aspect ratio) W/H of the wind tunnel width W to the air intake height H at which the sterilization rate reaches 99% within the arrival time T of 10 minutes is in the range of 0.5 to 2.0. When the aspect ratio W/H is 1.0, the sterilization rate reaches 99% in the arrival time T of 5.7 minutes, and the residence time τ of the sterilization target air 51 in the wind tunnel 509 is 0.0746 seconds. When the aspect ratio W/H is 0.5, the sterilization rate reaches 99% in the arrival time T of 9.9 minutes, and the residence time τ of the sterilization target air 51 in the wind tunnel 509 is 0.0664 seconds. When the aspect ratio W/H is 2.0, the sterilization rate reaches 99% in the arrival time T of 9.5 minutes, and the residence time τ of the sterilization target air 51 in the wind tunnel 509 is 0.0664 seconds.

The removal rate, odor removal rate, and dust removal rate depend on the gas-liquid contact rate, so an improvement in the removal rate is a prerequisite for an improvement in the gas-liquid contact rate. Therefore, if the aspect ratio W/H of the wind tunnel 509 is set to a reference value of 1.0, at which a sterilization rate of 99% is reached in the shortest time, and the aspect ratio W/H is within the range of reference values of -0.5 to +1.0, the flow rate and airflow state of the air to be sterilized 51 passing through the wind tunnel 509 can be optimized, and the short-circuiting of the air flow in the wind tunnel 509 can be prevented, maximizing the residence time of the air to be sterilized 51.

As a result, the spray of disinfectant solution that is sprayed from an upper position of the diagonally positioned media 506 toward the lower end of the media and flies along the upper surface of the media stays in the air for a longer period of time and is sufficiently diffused to wet the entire surface of the media 506, improving the contact time and frequency between the air to be sterilized 51 and the disinfectant solution, and enabling the device to be made more compact.

In addition, by placing the media 506 at an angle downward in the airflow path change area, the surface area of the media can be increased, increasing the gas-liquid contact area and improving the performance of removing airborne viruses, and contributing to the efficient use of space within the housing and the miniaturization of the device.

51 Air to be sterilized 52 Purification air passage 53 Spray device 54 Circulation tank 55 Circulation system 56 Chemical supply system 500 Housing 501 Door body 502 Air intake 503 Air supply port 504 First dustproof net 505 Dry filter 506 Media 507 Eliminator 508 Second dustproof net 509 Wind tunnel 531 Spray nozzle 541 Relay tank 542 Descending liquid guide plate 550 Circulation pump 551 Three-way flow path switching valve 552 Check valve 561 Generation device 562 Water supply system 563 Dilution water supply system 564 Preparation supply section 564b Three-way flow path switching valve 564c External take-out section 564d Flow rate adjustment valve 564e Water supply port 565 Relay pump 566 Replenishment supply section 567 Exhaust system 600 Fan device 651 Water supply port (strainer)
652 Delivery port 653 Solenoid valve 654 Flow meter 655 Electrolytic cell 656 Chemical pump 657 Hydrochloric acid cartridge 701 Upstream opening 702 Downstream opening 703 Opening surface 801 Opening 802 Electrode 900 Control device 901 Operation panel G Chlorine gas

Claims (1)

The air purifying device comprises a housing forming a purification air passage through which air to be sterilized flows from an upstream air intake port provided on the front surface of the exterior to an downstream air supply port, a sprayer which sprays a germicide solution into the air to be sterilized flowing through the purification air passage, a medium located upstream of the sprayer in the flow direction of the air to be sterilized and which retains the germicide solution sprayed from the sprayer, and a wind tunnel which forms the purification air passage and contains the medium to form an air-liquid contact area where the air to be sterilized comes into contact with the germicide solution,
the wind tunnel has an upstream opening facing horizontally opposite the air intake port and a downstream opening facing upward, forming an airflow path changing region where the airflow path of the air to be sterilized changes from horizontal to upward, and the ratio W/H of the wind tunnel width W, which is the width of the downstream opening along the front-to-rear direction of the exterior of the housing, to the air intake height H, which is the height of the upstream opening, is in the range of -0.5 to +1.0 with a reference value of 1.0;
The air purifying device is characterized in that the media is arranged inside the wind tunnel at an incline diagonally downward from the upstream opening side toward the rear side of the exterior of the housing, and the inclination angle with respect to the opening plane of the downstream opening is in the range of -19° to +18° with a reference value of 45° .

Images