JPH1147545A - Indoor air cleaning method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indoor air cleaning method and apparatus capable of removing part of an organic gas and an inorganic gas which are pollutants in air in a room by a simple method. SOLUTION: Air within a room is made to bubble in water in a cooled water tank 11 so as to absorb an organic gas and an inorganic gas which are soluble in water, and then the water is moved to another water tank 12 set at a temperature higher than room temperature by a pump system 20, and a gas emission of which is permitted (carbon dioxide and the like) is emitted outdoor and a constituent emission of which is not permitted is circulated and is removed as waste water to a sewage system when its content reaches a specified concentration, and thus indoor air is cleaned. A photocatalyst is installed on inner wall faces of the two water tanks, which can be irradiated with ultraviolet rays so that quality of the water in the tanks 11, 12 are kept good and growth of microorganisms is suppressed and organic substances absorbed in the water can be decomposed and removed to some extent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for purifying indoor air, and more particularly, to a method and apparatus for purifying air by absorbing contaminant gas in a room using water.

[0002]

2. Description of the Related Art Conventionally, most of indoor air purifying methods and apparatuses used for adsorbing and removing particles and molecular substances by ionization and adsorbents, and others using a photocatalyst.

[0003]

The above-mentioned air purifiers utilizing ions, adsorbents and photocatalysts are quite effective for dusting. However, organic gas is not sufficiently removed depending on the components, and inorganic gas is not sufficiently removed. It has little effect on carbon dioxide, which is a type of carbon dioxide.

For this reason, when a large number of people are present in a room with little ventilation or when a combustion type heater such as a fan heater is operated for a long time, even if the conventional air purifier is operated, the indoor Since carbon dioxide and the like in the air cannot be removed, the concentration becomes high, which may cause a bad mood. on the other hand,
As a general method for separating and removing carbon dioxide contained in the air, an amine adsorption method and a pressure method are in the range of practical use.However, such devices are generally large, and are generally used in homes and buildings. Is difficult to use. Further, a membrane separation method and the like have been studied, but the performance is not sufficient.

Accordingly, an object of the present invention is to provide a method and an apparatus for cleaning indoor air which can remove a part of organic gas and inorganic gas which are pollutants in indoor air by a simple method.

[0006]

Means for Solving the Problems After indoor air is bubbled into cooled water in a water tank to absorb water-soluble organic and inorganic gases which cannot be removed by a conventional air purifier, The water is pumped to another water tank set at a temperature higher than room temperature, and gas that can be released (carbon dioxide gas, etc.) is released outdoors, and components that cannot be released are circulated to reach a certain concentration. Then, by removing the wastewater as wastewater, the indoor air is purified and the above-mentioned problem is solved. In addition, a photocatalyst is provided on the inner wall surface of the two tanks and a structure that can irradiate ultraviolet rays is used to maintain good water quality in the tanks and suppress the generation of microorganisms, as well as organic substances absorbed in the water. Can be decomposed and removed to some extent.

According to the present invention, a part of organic or inorganic gas, which is a pollutant in indoor air, is exhausted from the indoor by a simple method and apparatus without substantially changing the temperature and humidity of indoor air. It can be removed and the room air can be kept clean for a long time by combining with a conventional air purifier.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a method and an apparatus for cleaning indoor air according to the present invention will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of an indoor air cleaning device according to the present invention. As shown in the figure, a water tank 11 for absorbing contaminants in the air in the room into water is provided indoors, and a water tank 12 for discharging gas to the outside or draining the water outdoors is installed outdoors. The water tank 11 is provided with a cooler 15 so as to be maintained at a temperature lower than room temperature.
Is provided with a heater 16 so as to be maintained at a temperature higher than room temperature. The heat discharged from the cooler 15 passes through the heat discharge pipe 35 and is used for keeping the water tank 12 warm. Water tank
1 and the water in the water tank 12 can be circulated by the water circulation pump system 20 through the pipes 23 and 24. Note that an electronic cooler, a gas cooler, or the like is used as the cooler 15.

[0010] The contaminated air in the room is guided from the indoor air intake 21 through a pipe 22 by an air pump 13 to a porous body 17 for air bubbling provided in a water tank 11 cooled by a cooler 15. Very fine bubbles pass through the water as the pollutants are absorbed into the water. The porous body 17 is made of ceramic (including glass) or plastic having fine pores. The air that has been cleaned by the contaminants being absorbed by the water is brought to approximately room temperature by the gas temperature controller 19 provided on the pipe 32 and returned to the room.

The water having absorbed the contaminants is sent to a water tank 12 by a water circulation pump system 20. The outside air is supplied from the outside air intake 28 to the pipe 27 by the air pump 14.
Is guided to the porous body 18 for air bubbling provided in the water tank 12 heated by the heater 16 and passes through the water as very fine bubbles. At that time, water tank 12
Since the temperature of the water is set to be high, among the contaminants absorbed in the water, those that can be released are more efficiently discharged from the gas discharge port 31 by the fine bubbles of the outside air at that time. Those that cannot be released as gas are left as they are, and the water is returned to the water tank 11 again. The circulation is repeated, and the water quality of the components that cannot be released from the water is constantly monitored in the water tank 12 by the water quality monitor 34, and when the concentration becomes equal to or higher than the set value in the water quality monitor 34, the valve 25 is opened and the pipe 26 is opened. And fresh water is supplied from a water supply port 30 through a valve 29 provided in a pipe 33.

FIG. 2 is a view showing the inside of the water tank 11 and the water tank 12. As shown in FIG. The photocatalyst 38 is applied inside the water tanks 11 and 12. In addition, a waterproof fluorescent lamp 37 is arranged so as to irradiate the wall with light. Therefore, the organic matter in water can be decomposed and removed to some extent by the photocatalytic effect, and the propagation of fungi can be reduced, so that the apparatus according to the present invention can be operated without maintenance for a longer time.
A heat insulating material 36 is attached to the outer surfaces of the water tanks 11 and 12.

By using the above-described indoor air purifying apparatus in combination with another conventional air or air purifier using an ion or adsorbent or a photocatalyst, the indoor air can be maintained in a clean state for a longer time.

[0014]

Next, an embodiment of the present invention will be described.

Example 1 In order to confirm the principle of air purification in the apparatus shown in FIG. 1, the solubility of carbon dioxide, one of the contaminants contained in the air, in water was measured. The result as shown in FIG. 3 was obtained. From these results, it can be seen that the solubility differs greatly between 5 ° C. and 30 ° C., and that a large amount of gas absorbed at low temperature is released at high temperature.
Of course, this device is effective for other components having high solubility in water.

To realize a simulated room, a closed space of about 2 m square was prepared, from which air could be circulated to the apparatus shown in FIG. The temperature in the simulation room was set to 20 ° C., which is the standard temperature. The size of the two tanks is about 50c
m, the water tank to be cooled is set to about 5 ° C. using an electronic cooler as a cooler, and the water tank to be heated is set to about 30 ° C.
Set to ° C. About 10 as porous body for air bubbling
An alumina ceramic body having a hole of about μm was used.
A titanium oxide photocatalyst was formed on the inner wall of the water tank by a dip coating method, and two fluorescent lamps were provided so that light could be irradiated. The flow rate of the air pump was set to about 1 L / min. A test was conducted in which 1200 ppm of carbon dioxide gas was introduced as a contaminant into the simulation chamber to operate the apparatus. At this time, the concentration of carbon dioxide on the discharge side (open system with outside air) is about 300
ppm. As a result of the test, after about 10 minutes, the carbon dioxide gas concentration in the simulation chamber was about 300 ppm, which is the same as that of the outside air. In addition, when a carbon dioxide gas having a concentration of 1200 ppm was introduced into the simulated chamber every other hour and operated for 8 hours, the concentration was high immediately after the introduction, but after several minutes, it was confirmed that the carbon dioxide concentration was almost the same as the outside air. Was.

(Example 2) In order to realize a simulated room, a closed space of about 3 m square was prepared, from which air could be circulated to the apparatus shown in FIG. The temperature in the simulation room was set to 20 ° C., which is the standard temperature. The size of the two water tanks was about 75 cm square, the water tank to be cooled was set to about 5 ° C. using a gas cooler as a cooler, and the water tank to be heated was set to about 30 ° C. A Teflon body having a hole of about 10 μm was used as a porous body for air bubbling. A titanium oxide photocatalyst was formed on the inner wall of the water tank by a dip coating method, and two fluorescent lamps were provided so that light could be irradiated. The flow rate of the air pump was set to about 3 L / min. A test was conducted in which 1200 ppm of carbon dioxide gas was introduced as a contaminant into the simulation chamber to operate the apparatus. At this time, the concentration of carbon dioxide on the discharge side (open system with outside air) is about 300
ppm. As a result of the test, after about 10 minutes, the concentration of carbon dioxide in the simulation chamber was about 300 ppm, which is the same as that of the outside air. In addition, when a carbon dioxide gas having a concentration of 1200 ppm was introduced into the simulation chamber every one hour and operated for 8 hours, the concentration became high immediately after the introduction, but after several minutes, it was confirmed that the carbon dioxide concentration became almost the same as the outside air. did it.

Example 3 In order to realize a simulated room, a closed space of about 2 m square was prepared, from which air could be circulated to the apparatus shown in FIG. The temperature in the simulation room was set to 20 ° C., which is the standard temperature. The size of the two water tanks was about 50 cm square, the water tank to be cooled was set to about 5 ° C. using an electronic cooler as a cooler, and the water tank to be heated was set to about 30 ° C. A porous silica material having holes of about 10 μm was used as a porous material for air bubbling. A titanium oxide photocatalyst was formed on the inner wall of the water tank by a dip coating method, and two fluorescent lamps were provided so that light could be irradiated. The flow rate of the air pump was set to about 1 L / min. A test was conducted in which 1200 ppm of carbon dioxide, 10 ppm of ammonia, and 10 ppm of acetaldehyde were introduced as contaminants into the simulated chamber to operate the apparatus. At this time, the concentration of carbon dioxide on the discharge side (open system with outside air) was about 300 ppm, and the levels of ammonia and acetaldehyde could not be detected. As a result of the test, after about 10 minutes, the concentration of carbon dioxide in the simulated chamber became about 300 ppm, which is the same as that of the outside air, and the levels of ammonia and acetaldehyde could not be detected. In addition, when three kinds of gases having the same concentration were introduced into the simulated chamber every other hour and operated for 8 hours, it was confirmed that the concentration was high immediately after the introduction, but became almost the same as the outside air several minutes later. . Under these conditions, the concentrations of ammonia and acetaldehyde in the aquarium could not be detected by the water quality monitor.

(Example 4) In order to realize a simulated room, a closed space of about 2 m square was prepared, from which air could be circulated to the apparatus shown in FIG. A commercial indoor air purifier using ions and adsorbent was installed in the simulated indoor space. The temperature in the simulation room was set to 20 ° C., which is the standard temperature. The size of the two water tanks was about 50 cm square. The water tank to be cooled was set to about 5 ° C. using an electronic cooler as a cooler, and the water tank to be heated was set to about 30 ° C. A porous silica material having holes of about 10 μm was used as a porous material for air bubbling. A titanium oxide photocatalyst was formed on the inner wall of the water tank by a dip coating method, and two fluorescent lamps were provided so that light could be irradiated. The flow rate of the air pump was set to about 1 L / min. A test was conducted in which 1000 ppm of carbon dioxide gas, 10 ppm of ammonia, 1 ppm of formaldehyde and 1 ppm of trimethylamine were introduced as contaminants into the simulation chamber, and the apparatus according to the present invention and the air purifier installed in the simulation chamber were operated. At this time,
The concentration of carbon dioxide on the discharge side (open system with outside air) is about 300pp
At m, ammonia, formaldehyde and trimethylamine were at undetectable levels. As a result of the test, after about 10 minutes, the carbon dioxide gas concentration in the simulation
m, and ammonia, formaldehyde and trimethylamine were at undetectable levels. As a comparative example, an experiment was conducted in which the operation of the air purifier in the simulated room was stopped under the same conditions. Only trimethylamine, which has low solubility in water, was reduced only slightly, and all other components were removed (at the same level as outside air). )did it. As a comparative example, when the apparatus according to the present invention was stopped under the same conditions and only a commercially available air purifier installed in the simulated room was operated, formaldehyde and trimethylamine were almost completely removed, but carbon dioxide gas was reduced. It was found that some ammonia remained.

[0020]

As described above, according to the present invention, a part of the organic gas and the inorganic gas, which are pollutants in the indoor air, can be partially removed by a simple method without substantially changing the temperature of the indoor air. In addition, by combining with an air cleaner using a conventional ion or adsorbent or a photocatalyst, the indoor air can be kept clean for a longer time.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an indoor air cleaning device according to the present invention.

FIG. 2 is a view showing the inside of the water tank shown in FIG.

FIG. 3 is a diagram showing the amount of carbon dioxide gas that can be dissolved in water.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Water tank 12 Water tank 13,14 Air pump 15 Cooler 16 Heater 17,18 Porous body for air bubbling 19 Gas temperature controller 20 Water circulation pump system 21 Indoor air intake 22,23,24,26,27,32, 33 pipe 25, 29 valve 28 outside air intake 30 water supply port 31 gas discharge port 34 water quality monitor 35 heat discharge pipe 36 heat insulating material 37 fluorescent lamp 38 photocatalyst

Claims (10)

[Claims] 1. A method for cleaning indoor air, comprising: absorbing contaminants in the air in a room into water in a cooled water tank; and moving the water to another water tank to remove the contaminants to the outside. . 2. Among the pollutants in the indoor air that dissolve in water, after bubbling and absorbing the indoor air into the water in the cooled water tank, the water is moved to another water tank. The indoor air cleaning method according to claim 1, wherein the air is heated and removed as a gas outside the room. 3. The indoor air cleaning method according to claim 2, wherein components that cannot be removed outside as a gas even when heated are removed as wastewater when the concentration reaches a certain level or more. 4. A water tank installed indoors and kept at a temperature lower than room temperature, a water tank installed outdoors and kept at a temperature higher than room temperature, and a pump system for circulating water in both water tanks, which are arranged indoors. An indoor air purifying apparatus characterized in that an air bubbling device capable of bubbling indoor air is provided in a water tank provided and an outdoor air is provided in a water tank arranged outdoors. 5. The indoor air cleaning device according to claim 4, wherein the bubbling device includes a pump for sending air to a water tank and a porous body having pores attached to a pipe. 6. The bubbling device for a water tank installed in the room is provided with a pipe for returning purified air from the water tank into the room, and the pipe is provided with a temperature control device. The indoor air cleaning device according to claim 4. 7. The water tank installed in the room is provided with a cooler for cooling water, and heat discharged from the cooler is used for keeping the temperature of the water tank installed outdoors. The indoor air purifying device as described in the above. 8. The indoor air cleaning apparatus according to claim 4, wherein a water quality monitor is provided in the water tank installed outdoors. 9. A photocatalyst is provided on an inner wall surface of the water tank installed indoors and outdoors, and a light source for emitting ultraviolet light capable of irradiating the inner wall surface is provided in the water tank.
The indoor air purifying device as described in the above. 10. An indoor air purifying apparatus characterized by using the air purifying apparatus according to claim 4 together with another air purifier.