JPH1043543A - Method for purifying polluted air and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically adjust a soil layer so as to contain always an adequate amt. of moisture. SOLUTION: Polluted air is supplied by a blower 8 into the soil layer 6 in a vessel 4. This polluted air passes the inside of the soil layer 6. The polluted air is thus purified by the effect of the microorganisms, etc., included in the soil layer 6. A thermometer 10A measures the temp. of the polluted air in the vessel 4 and a thermometer 10B measures the temp. of the soil layer 6. A controller 14 determines a temp. difference by subtracting the temp. of the soil layer 6 measured by the thermometer 10B from the temp. of the polluted air measured by the thermometer 10A. When this temp. difference is lower than a reference value, judgment is made that the soil layer 6 is overdried. Solenoid valves 36, 42 are then opened to supply the water to the soil layer 6 from shower nozzles 34 and water feed pipes 40. As a result, the moisture of always the adequate amt. is included in the soil layer 6 and the air purification effect possessed by the microorganisms and the soil is efficiently exhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for purifying air contaminated with exhaust gas emitted from automobiles, factories, etc., and more particularly, to a method for purifying air contaminated by passing microorganisms through a soil layer where they can grow. The present invention relates to a method and an apparatus for purifying air.

[0002]

2. Description of the Related Art As a device for purifying air contaminated with exhaust gas discharged from automobiles and factories, the present applicant has proposed various types using soil from the viewpoint of protection of the global environment. . Such an air purification device using soil includes a soil layer in which microorganisms can propagate and air can flow, and an air flow unit that allows contaminated air to pass through the soil layer. Then, the contaminated air is passed through the soil layer by the air flow means, the harmful substances are attached to the soil particles, and the harmful substances are absorbed by microorganisms, thereby purifying the contaminated air.

On the other hand, in order to activate the function of soil particles to adhere harmful substances and the function of microorganisms to absorb harmful substances, that is, to activate the air purification action of the soil layer, It is desirable to maintain the moisture content of the constituent soil at or above a predetermined value.

[0004]

Therefore, it is necessary to monitor the degree of dryness of the soil layer and to replenish water as necessary. Particularly, it is necessary to automatically replenish such water.
It is desirable in terms of labor saving. Monitoring of the dryness of the soil layer can be performed by measuring the amount of water contained in the soil layer, and specifically, a pF meter may be used.

[0005] However, the pF meter has a drawback that it is easily broken, and since water must be retained in the pF meter in principle for measurement, water lost due to evaporation is periodically removed. Maintenance is needed to replenish.

Accordingly, an object of the present invention is to monitor the dryness of a soil layer without using a pF meter in purifying contaminated air using soil in which microorganisms have been propagated, so that the soil layer always contains an appropriate amount of moisture. It is an object of the present invention to provide a method and an apparatus for purifying contaminated air, which can automatically adjust the air quality and efficiently exert the air purifying action of microorganisms and soil.

[0007]

In order to achieve the above object, the present invention provides a method for purifying contaminated air by passing the contaminated air through a soil layer in which microorganisms can propagate and air can flow. In the purification method, measuring the temperature of the contaminated air before entering the soil layer, measuring the temperature of the soil layer, based on the difference between the measured temperature of the contaminated air and the temperature of the soil layer, It is characterized by supplying water to the soil layer.

Further, the present invention provides a soil layer in which microorganisms can propagate and air can flow, air flow means for passing contaminated air through the soil layer, and water replenishing means for replenishing the soil layer with water. A first temperature measuring means for measuring the temperature of the contaminated air at a point before the contaminated air enters the soil layer, and a second temperature measuring means for measuring the temperature of the soil layer. And temperature control means for controlling the water replenishment means based on a difference between the temperature of the contaminated air measured by the first and second temperature measurement means and the temperature of the soil layer. It is characterized by the following.

Further, the present invention is characterized in that the air flowing means passes the contaminated air through the soil layer by pumping the contaminated air to the soil layer. Further, the present invention is characterized in that the air flow means sucks the contaminated air through the soil layer to pass through the soil layer. Further, the present invention is characterized in that the soil layer is provided in a container, and the first temperature measuring means measures the temperature of the contaminated air in the container. Further, the present invention is characterized in that the water replenishing means sprinkles water on the surface of the soil layer to replenish water to the soil layer. Further, the present invention is characterized in that the water supply means supplies water to the soil layer through a pipe buried in the soil layer, and replenishes the soil layer with water. Further, the present invention is characterized in that the water replenishing means mixes the contaminated air to be pumped into the soil layer with water in a mist state and replenishes the soil layer with water.

[0010] The difference between the temperature of the contaminated air before entering the soil layer and the temperature of the soil layer is an indicator of the dryness of the soil layer. That is, as the amount of moisture contained in the soil layer increases, the moisture contained in the soil layer evaporates when contaminated air passes, and the heat of vaporization is taken away, so that the temperature of the soil layer decreases. Therefore, in this case, the temperature difference becomes large. Conversely, the smaller the amount of moisture contained in the soil layer, the less heat of vaporization is removed from the soil layer, and the smaller the temperature difference. Therefore, by supplying water to the soil layer in accordance with the temperature difference based on the method for purifying contaminated air of the present invention, the amount of water contained in the soil layer can always be kept at an appropriate value.

Further, in the polluted air purifying apparatus of the present invention, the first temperature measuring means measures the temperature of the contaminated air before the contaminated air enters the soil layer, and the second temperature measuring means is Measure the temperature of the soil layer. The control means controls the water replenishing means based on the difference between the temperature of the contaminated air measured by the first and second temperature measuring means and the temperature of the soil layer, and replenishes water to the soil layer. The difference between the temperature of the contaminated air and the temperature of the soil layer is
Since the degree of dryness of the soil layer is represented as described above, the amount of water contained in the soil layer can always be kept at an appropriate value by such control.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic explanatory view showing a contaminated air purifying apparatus of the present invention for implementing the contaminated air purifying method of the present invention. The contaminated air purification device 2 includes a container 4, a soil layer 6, a blower 8 (air flowing means according to the present invention), thermometers 10A and 10B, a water supply device 12 (water replenishing means according to the present invention), a control device 14, and the like. And installed at a location close to a road with heavy traffic, for example.

The shape of the container 4 is substantially a rectangular parallelepiped. Container 4
A floor 16 of a soil layer formed of a mesh-like member such as a wire mesh is disposed at a lower portion of the inside, and a soil layer 6 is provided thereon. The soil layer 6 is soil in which microorganisms can proliferate. In the embodiment, the soil layer 6 is composed of a mixture of ando, mulch, and pearlite in a volume ratio of 3: 1: 1 to increase the porosity so that air can flow. The thickness of the soil layer 6 is 40 cm in this embodiment. Plantings 18 are planted on top of the soil layer 6, while the bottom of the container 4 and the floor 1
6, a lower space portion 20 is formed.

The blower 8 is arranged close to the container 4, and the discharge port 22 is connected through a pipe 26 to an opening 24 formed in the lower space 20 on the side of the container.
The end of a tube 30 is connected to the suction port 28 of the blower 8,
Contaminated air is sucked in from the other end of the tube 30.

Above the container 4, a plurality of shower nozzles 34 constituting the water supply device 12 are disposed with their jet ports facing downward.
Is connected to a water supply facility (not shown) through a water supply pipe 38 to which is attached. On the other hand, the water supply device 12
The water supply pipe 40 in which a number of holes are formed constitutes the container 4
The solenoid valve 42 is attached on the way, and the end of the end is connected to the water supply pipe (not shown) of the water supply pipe 38 through a pipe 50 penetrating the side wall of the container 4. It is connected to.

A thermometer 10A is provided in the lower space 20 of the container 4, and a thermometer 10B is provided below the water supply pipe 40 in the soil layer 6.

The control device 14 is constituted by a personal computer that operates according to a predetermined program.
Solenoid valve 3 based on the output signals of thermometers 10A and 10B
6, 42 and the blower 8 is controlled.

Next, the operation of the contaminated air purification device 2 configured as described above will be described. The operator operates the control device 14
Is operated to instruct the activation of the blower 8, the control device 14
Sends a predetermined signal to the blower 8 to turn on the power of the blower 8. As a result, the blower 8 starts blowing air, sucks the contaminated air from the tube 30, and sends the contaminated air into the lower space 20 of the container 4 through the tube 26. The contaminated air sent into the lower space portion 20 passes through the soil layer 6 having a high porosity and exits the container from the upper surface of the soil layer 6.

When the contaminated air passes through the soil layer 6, dust is trapped by the physical action of a soil filter, and impurities such as hydrocarbon gas such as methane are adsorbed. In addition, microorganisms in the soil layer 6 decompose contaminants such as impurity components. Aerobic microorganisms proliferate on the surface of the soil layer 6 or on a portion where air flows inside the soil layer 6, and anaerobic microorganisms proliferate on a portion where air does not flow inside the soil layer 6. Therefore, for example, carbon monoxide is mainly converted into carbon dioxide and methane gas is mainly decomposed into carbon dioxide and water by being consumed in the cells of these microorganisms or used for respiration. As a result, clean air from which contaminants have been removed is returned to the atmosphere from the surface of the soil layer 6.

In order to effectively exert such an air purifying action, the amount of water contained in the soil layer 6 must be appropriate. In this embodiment, the amount of water in the soil layer 6 is as follows. It is controlled as follows. That is, the thermometer 10A disposed in the lower space portion 20 of the container 4
The controller measures the temperature of the contaminated air before entering the controller, and outputs an electric signal representing the measurement result to the controller. Meanwhile, soil layer 6
The thermometer 10B arranged inside measures the temperature of the soil layer,
An electric signal representing the measurement result is output to the control device 14.

The difference between the temperature of the contaminated air before entering the soil layer 6 measured by the thermometer 10A and the temperature of the soil layer 6 measured by the thermometer 10B is an index of the dryness of the soil layer 6. . That is, as the amount of moisture contained in the soil layer 6 increases, the moisture contained in the soil layer 6 evaporates and contaminates the heat of vaporization when the contaminated air passes, so that the temperature of the soil layer 6 decreases. Therefore, in this case, the temperature difference becomes large. Conversely, the smaller the amount of moisture contained in the soil layer, the less heat of vaporization is removed from the soil layer, and the smaller the temperature difference.

The controller 14 obtains the temperature of the contaminated air before entering the soil layer 6 and the temperature of the soil layer 6 based on the electric signals from the thermometers 10A and 10B, and subtracts the latter from the former to obtain the temperature. The difference is obtained, and the temperature difference is compared with a reference value held in advance. If the temperature difference is lower than the reference value, it is determined that the soil layer 6 is too dry, and an electric signal is sent to the solenoid valves 36 and 42 to open each valve.
As a result, water spouts out of the shower nozzle 34 and the water supply pipe 40, and water is supplied to the soil layer 6 from both the surface and the inside of the layer, and water is replenished.

The controller 14 continues to supply water, for example, for about 30 minutes, at which stage the temperature difference is obtained again and compared with a reference value. And when the temperature difference is higher than the reference value,
Assuming that sufficient water has been supplied to the soil layer 6, the solenoid valve 3
6 and 42 are closed, and the supply of water to the soil layer 6 is stopped.

Thereafter, the control device 14 operates as follows:
The measurement result of B is constantly monitored, and when the temperature difference falls below the reference value, water is supplied to the soil layer 6 as described above. As a result, the amount of moisture contained in the soil layer 6 is always maintained at an appropriate value, and the microorganisms and the soil layer 6 effectively exert the air cleaning action.

When nitrogen oxides are removed by the soil layer 6, it is known that the water content of the soil layer 6 becomes optimum when the pF is about 1.5. Therefore, it is desirable to control the hydration so as to obtain such a pF. By the way, as described above, the soil layer 6 of this embodiment is
It is a mixture of humus and perlite at a ratio of 3: 1: 1, and the thickness of the soil layer 6 is 40 cm. In the case of such a soil layer 6, the relationship between pF and the temperature difference is as follows. According to experiments, the results are as shown in [Table 1].
The unit of the temperature is (° C.).

[0026]

[Table 1] From this table, when the temperature of the contaminated air is around 20 ° C,
The pF becomes 1.5 when the temperature difference is 0.9 by linear interpolation.
When the temperature of the contaminated air is around 30 ° C., the pF becomes 1.5 when the temperature difference is about 3.4 ° C. by linear interpolation. Therefore, the pF of the soil layer 6 can be maintained at about 1.5 by using this temperature difference or a close value as a reference value according to the temperature of the contaminated air. However, since the relationship between the value of pF and the temperature difference changes depending on the soil type, soil layer thickness, type of mixed material, and the like, the above-mentioned reference value should be set to a value suitable for the device if the device changes. is there.

As described above, in this embodiment, the degree of dryness of the soil layer 6, that is, the amount of moisture contained in the soil layer is monitored by the difference between the temperature of the contaminated air and the temperature of the soil layer 6,
Therefore, since it is not necessary to use a pF meter, the problem that the pF meter is easily broken and maintenance is required is solved.

In this embodiment, the contaminated air is pressure-fed into the lower space portion 20 by the blower 8. However, the blower 8 is mounted in the opposite direction, and the air is sucked from the lower space portion 20, so that the soil layer 6 is removed. It is also possible to adopt a configuration in which contaminated air is sucked from the surface. However, in this case, in order to measure the temperature of the contaminated air before entering the soil layer 6, the thermometer 1
OA is arranged outside the container 4 at a location close to the surface of the soil layer 6, for example.

In the above embodiment, the water was supplied to the soil layer 6 by both the shower nozzle 34 provided above the soil layer 6 and the water supply pipe 40 buried in the soil layer 6. It is not necessary to use both at the same time, and it is also possible to adopt a configuration in which only one of them is provided.

When water is sprinkled from above the soil layer 6,
It is of course possible to use the same type of water supply pipe 38 instead of the shower nozzle 34.

Further, as a method of supplying water to the soil layer, as shown by an imaginary line in FIG. 1, a spray nozzle 48 is provided in the middle of the tube 26, and water is sprayed from this nozzle to form the tube 26. It is also possible to spray water into the soil layer together with the contaminated air to replenish moisture.

In the above embodiment, the shower nozzle 3
The supply of water to the shower nozzle 34 and the water supply pipe 40 was performed by controlling the pumps instead of the solenoid valves. Of course, control is also possible.

[0033]

As described above, the present invention relates to a method for purifying contaminated air by purifying the contaminated air by passing the contaminated air through a soil layer in which microorganisms can propagate and air can flow. Measuring the temperature of the contaminated air before entering the layer, measuring the temperature of the soil layer, and rehydrating the soil layer based on the difference between the measured temperature of the contaminated air and the temperature of the soil layer. I did it.

The present invention also provides a soil layer in which microorganisms can propagate and air can flow, air flow means for passing contaminated air through the soil layer, and water supply means for supplying moisture to the soil layer. A first temperature measuring means for measuring the temperature of the contaminated air at a location before the contaminated air enters the soil layer, and a second temperature measuring means for measuring the temperature of the soil layer. And a control means for controlling the water replenishing means based on a difference between the temperature of the contaminated air measured by the first and second temperature measuring means and the temperature of the soil layer. And

Therefore, according to the present invention, the soil layer can be automatically adjusted so as to always contain an appropriate amount of moisture, and the air purification action of microorganisms and soil can be efficiently exhibited. In the present invention, since it is not necessary to use a pF meter for monitoring the water content, the problem that the pF meter is easily broken and maintenance is not required does not occur.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one example of a contaminated air purification device of the present invention for implementing a contaminated air purification method of the present invention.

[Explanation of symbols]

 2, 44 Air purification device 4 Container 6 Soil layer 8 Blower 10A, 10B Thermometer 12 Water supply device 14 Control device 20 Air chamber 26, 30, 50 Pipe 34 Shower nozzle 36, 42 Electromagnetic valve 38, 40 Water supply pipe 48 Spray nozzle

Continued on the front page (72) Inventor Shinichiro Sato 4-6-115 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd. ) Inventor Kazushi Takahashi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Yasuhiro Tsuchiya 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (8)

[Claims] 1. A method for purifying contaminated air by passing contaminated air through a soil layer in which microorganisms can propagate and through which air can flow, wherein the contaminated air before entering the soil layer Measuring the temperature of the soil layer, supplying water to the soil layer based on a difference between the measured temperature of the contaminated air and the temperature of the soil layer, contaminated air. Purification method. 2. A soil layer in which microorganisms can propagate and air can flow, air flow means for passing contaminated air through the soil layer, and water supply means for supplying moisture to the soil layer. In the contaminated air purification device, first temperature measuring means for measuring the temperature of the contaminated air at a point before the contaminated air enters the soil layer, and second temperature measuring means for measuring the temperature of the soil layer Means, and control means for controlling the water replenishing means based on a difference between the temperature of the contaminated air measured by the first and second temperature measuring means and the temperature of the soil layer. And contaminated air purification equipment. 3. The apparatus for purifying contaminated air according to claim 2, wherein the air flowing means passes the contaminated air through the soil layer by pumping the contaminated air to the soil layer. 4. The contaminated air purification device according to claim 2, wherein the air flowing means sucks the contaminated air through the soil layer to pass through the soil layer. 5. The contaminated air purification device according to claim 2, wherein the soil layer is provided in a container, and the first temperature measuring means measures the temperature of the contaminated air in the container. 6. The contaminated air purification apparatus according to claim 2, wherein the water replenishing means sprinkles water on the surface of the soil layer to replenish moisture to the soil layer. 7. The contaminated air purification device according to claim 2, wherein the water supply means supplies water to the soil layer through a pipe buried in the soil layer, and replenishes the soil layer with water. 8. The contaminated air purification apparatus according to claim 3, wherein the water replenishing means mixes the contaminated air to be pumped to the soil layer with water in a mist state and replenishes the soil layer with water.