JPH0523542A - Harmful gas removing apparatus - Google Patents

Abstract

PURPOSE:To effectively remove carbon monoxide even when the temp. of air to be treated is high by a method wherein air to be treated introduced into an apparatus is pressurized by a pressurizing means to be sent into a condensing pipe under pressure to remove steam before passed through a catalyst filter. CONSTITUTION:The interior of a cylindrical apparatus main body 10 is demarcated into a lower air introducing chamber 12 and an upper air treatment chamber 13 by a dehumidifier 11. A prefilter 15 is provided to the air inlet 14 of the air introducing chamber 12 and an air pump 16 is provided in said chamber 12 to suck and pressurize air to be treated to supply said air to the dehumidifier 11 under pressure. The interiors of the lower lid 19 and upper lid 20 of the humidifier main body 11a are connected by a large number of condensing pipes 21 and a steam permeable membrane 22 is formed to the inner and outer peripheries of the air passage of the air treatment chamber 13. A catalyst filter 31 is arranged on the way of the air passage of the air treatment chamber 13. The air to be treated introduced into the main body 10 from the inlet 14 through the prefilter 15 is pressurized to be dehumidified by the condensation of moisture and passes through the catalyst filter 31. Therefore, the air to be treated is dehumidified to come into contact with a catalyst and carbon monoxide is effectively removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a harmful gas removing apparatus, and more particularly, a platinum-based catalyst or a palladium-based catalyst for cleaning exhaust gas generated in a chemical plant or the like, automobile exhaust gas, etc. The present invention relates to a harmful gas removing device for removing harmful gas containing carbon monoxide.

[0002]

2. Description of the Related Art Generally, in this type of harmful gas removing apparatus, an exhaust gas containing carbon monoxide is subjected to a catalytic reaction using a platinum-based catalyst or a palladium-based catalyst to produce non-toxic carbon dioxide or H ₂ O. It is made to oxidize (for example, refer to Japanese Patent Laid-Open No. 2-35915).

[0003]

However, in the above-mentioned conventional harmful gas removing apparatus, if the humidity of the air to be treated is high, the reactivity of the catalyst is lowered and the efficiency of removing carbon monoxide is lowered. Especially in the rainy season and summer, the humidity of the air to be treated is 9
It may reach 0%, and even if such high-humidity air is passed through the catalyst, it is almost impossible to remove harmful substances.

The invention according to claim 1 has been made in view of the above problems, and it is an object of the invention to provide a harmful gas removing device capable of removing carbon monoxide even when the humidity of the air to be treated is high. Has an aim. Further, in the exhaust gas, in addition to carbon monoxide, contains an organic malodorous component such as aldehyde and acetone, but since these harmful gases do not cause a catalytic reaction at room temperature, the exhaust gas is simply generated by a catalytic filter. There is a problem that harmful gas cannot be sufficiently removed only by filtering.

The present invention according to claim 2 has been made in view of the above problems, and is capable of removing harmful gases capable of removing carbon monoxide and organic malodorous components even when the air to be treated has high humidity. The purpose is to provide a device.

[0006]

In order to solve the above problems, the harmful gas removing apparatus according to claim 1 of the present invention removes harmful substances of the air to be treated introduced into the apparatus body by a filter mechanism. In the harmful gas removing device, pressurizing means for pressurizing the air to be treated introduced into the main body of the device, a condensing pipe for condensing moisture from the pressurized air to be treated to obtain dehumidified air, and a condensing pipe And a dehumidifier for dehumidifying the air to be treated supplied to the filter mechanism.

Further, in the harmful gas removing apparatus according to a second aspect of the present invention, in the structure according to the first aspect, the filter mechanism is arranged on the upstream side of the catalyst filter for oxidizing carbon monoxide and the catalyst filter. An adsorption filter filled with an adsorbent that absorbs malodorous components and that can be regenerated by heating;
And a heater for heating the adsorbent from the side of the adsorption filter to which the air to be treated is introduced.

[0008]

According to the harmful gas removing apparatus of the first aspect of the present invention, the air to be treated introduced into the apparatus main body is pressurized by the pressurizing means and pumped into the condensing pipe. Then, while water is condensed in the condensing tube, the water vapor contained in the air to be treated is removed from the water vapor permeable membrane,
The air to be treated passes through the catalyst filter while being dehumidified. Here, carbon monoxide contained in the air to be treated undergoes an oxidation reaction by the catalyst filter, is decomposed into carbon dioxide and H ₂ O, and is removed.

As described above, according to the harmful gas removing apparatus of the first aspect of the present invention, since the air to be treated introduced into the apparatus body is dehumidified by the dehumidifier, the reactivity of carbon monoxide by the catalyst is increased. Can be prevented from decreasing. In particular, the dehumidifier employed in the present invention, because all or part of the wall surface of the condenser tube is composed of a water vapor permeable membrane,
Dehumidification can be efficiently performed by combining the dehumidifying action of compressing and condensing water and discharging the condensed water as a drain, and the action of removing water vapor by passing through the water vapor permeable membrane.

Further, according to the harmful gas removing apparatus of the second aspect of the present invention, formaldehyde,
Organic malodorous components such as acetaldehyde, acetone and acrolein are adsorbed by the adsorbent. Furthermore, when hot air is generated by a heater provided on the treated air introduction side of the adsorption filter, the organic malodorous components adsorbed on the adsorbent are desorbed from the adsorbent and are oxidized by the catalytic filter to decompose. To be done.

[0011]

Embodiments will be described in detail below with reference to the drawings showing embodiments. FIG. 1 is a schematic sectional view of the harmful gas removing apparatus of the present invention.
Referring to, the tubular apparatus body 10 is partitioned by a dehumidifier 11 into an air introduction chamber 12 on the lower end side and an air treatment chamber 13 on the upper end side. The air introduction chamber 12 communicates with an air inlet 14 formed on the peripheral wall of the apparatus body 10, and the air inlet 14 is equipped with a prefilter 15 made of, for example, nylon non-woven fabric. Further, an air pump 16 is arranged in the air introduction chamber 12. The air pump 16 is for sucking the air to be treated such as exhaust gas from the air inlet 14 through the pre-filter 15, pressurizing the air to be treated and sending it to the dehumidifier 11 under pressure.

The dehumidifier 11 is, for example, a dehumidifier main body 11 formed of a stainless steel cylinder having a pressure resistance of about 5 kg / cm ^2.
The chamber CH, which is provided with a and is partitioned inside, communicates with the outside of the apparatus main body 10 via the discharge pipe 11b.
Further, the flanges 17 and 18 are provided on both ends of the dehumidifier body 11a.
Are integrally molded. A lower lid 19 for partitioning the upper surface of the air introduction chamber 12 and an upper lid 20 for partitioning the lower surface of the air treatment chamber 13 are fixed to the flanges 17 and 18, respectively. Both ends are communicated with the inside by a large number of condensing pipes 21 fitted and welded in the holes 17a, 18a of the flanges 17, 18 respectively. The condensing tube 21 is made of a ceramic material having open cells, a metal material (stainless steel), or the like, and it is possible to use, for example, one having a maximum pore diameter of 35 μm, an average pore diameter of 25 μm, and a porosity of 40%.

Referring to FIGS. 2 and 3, each condensing pipe 21
A water vapor permeable film 22 is formed on the inner and outer peripheral surfaces of the. The water vapor permeable membrane 22 has a function of selectively passing water vapor in the air to dehumidify it, and includes a fluororesin, polyacrylonitrile, polymethacrylonitrile, cellulose acetate, polycarbonate, butyl rubber, polystyrene, neoprene, 2- A film having a thickness of about 1 μm and made of a material such as 6-dimethylphenylene oxide, natural rubber, or polydimethylcyclohexane can be used. The water vapor permeable membrane 15b is manufactured by applying a polymer solution on the surface of a porous material having open cells and drying the solvent to form a thin film of 1 μm or less.

Returning to FIG. 1, the lower lid 19 of the dehumidifier 11 is described.
Is a pipe 25 for sending the compressed air of the air pump 16 into each condensing pipe 21, and a liquid level gauge 26 for detecting the waste water that has been dripped from the dehumidifier body 11a and accumulated in the lower lid 19.
And a drain pipe 27 for draining the drainage. 27a is a solenoid valve for opening and closing the drain pipe 27.

A pressure adjusting valve 28 for adjusting the pressure of the dehumidified air discharged from each condensing pipe 21 is provided on the upper lid 20.
And a pressure indicator 29 for indicating the pressure of dehumidified air filling the upper lid 20 are connected. The pressure adjusting valve 28 and the indicator 29 are provided in the air treatment chamber 1 of the apparatus body 10.
The pressure indicator 29, which is disposed inside the display unit 3, is visible from the outside.

The air treatment chamber 13 is provided with the piping 3 of the apparatus body 10.
The catalyst filter 31 as a filter mechanism is disposed in the middle of the air passage which communicates with the outside via 0. Referring to FIG. 4, the catalyst filter 31 is provided with a case 32, and the inside of the case 32 is filled with a platinum-based catalyst 33 having a diameter of, for example, about 2 mm. The upper surface and the lower surface of the catalyst 33 are covered with the metal net 34. In addition, in this embodiment, the inside of the case 32 is partitioned in a grid shape by a partition plate 35 made of aluminum so that the catalyst 33 is filled almost uniformly.

Next, the operation of this embodiment will be described with reference to FIG. According to the above configuration, the air to be treated introduced from the air inlet 14 into the apparatus main body 10 through the pre-filter 15 is pressurized by the air pump 16 and pumped from the pipe 25 into the condensing pipe 21 via the lower lid 29. To be done. Then, by condensing the water in the condensing pipe 21, the condensed water drops into the lower lid 19 and is further discharged as a drain from the drain pipe 27 to the outside of the system. When the exhaust gas contains water vapor, the water vapor is absorbed by the water vapor permeable film 22 of the condensing pipe 21.
(See FIGS. 2 and 3), and is further discharged from the chamber CH to the outside of the system via the discharge pipe 11b. As described above, the air to be treated is dehumidified by the dehumidifier 11, is regulated to a predetermined pressure by the pressure regulating valve 28, is discharged into the air treatment chamber 13, and the treated air after being dehumidified is discharged to the air treatment chamber 13. Passes through the catalyst filter 31 and is discharged from the air outlet 30 to the outside of the system. Here, carbon monoxide contained in the air to be treated undergoes an oxidation reaction by the catalyst filter 31, is decomposed into carbon dioxide and H ₂ O, and is discharged from the air outlet 30 to the outside of the system.

As described above, according to this embodiment, the apparatus body 1
Since the air to be treated introduced into 0 is dehumidified by the dehumidifier 11, it is possible to prevent the reactivity of carbon monoxide by the catalyst from decreasing. Particularly, in the dehumidifier 11 employed in this embodiment, the inner and outer peripheral surfaces of the condensing pipe 21 are entirely formed of the water vapor permeable membrane 22 (see FIGS. 2 and 3), so that the moisture is compressed. Then, the dehumidifying action of condensing the condensed water and discharging the condensed water as a drain and the action of removing the water vapor by passing through the water vapor permeable membrane can be efficiently performed.

Therefore, according to the structure of the above embodiment, carbon monoxide can be removed even when the air to be treated has high humidity. FIG. 5 shows the catalyst filter 31, the activated carbon filter 36 serving as an adsorption filter arranged upstream of the catalyst filter 31, and the honeycomb arranged upstream of the activated carbon filter 36 as components of the filter mechanism. An example including a PTC heater 37 is shown. The PTC heater 37 is controlled by, for example, a timer to operate the device for a certain time and then
It is for generating hot air of 0 to 200 ° C. The activated carbon filter 36 is filled with granular activated carbon as an adsorbent.

Next, the operation of the embodiment shown in FIG. 5 will be described.
Similar to the embodiment described with reference to FIG. 1, the air to be processed that has been pressure-fed by the air pump 14 is dehumidified by the dehumidifier 11, and is discharged into the air processing chamber 13 while being adjusted to a predetermined pressure by the pressure adjusting valve 28. It Then, the air to be treated after dehumidification passes through the activated carbon filter 36 and further to the catalyst filter 3
1 is discharged from the air outlet 30 to the outside of the system. Organic malodorous components such as formaldehyde, acetaldehyde, acetone and acrolein contained in the air to be treated are adsorbed by the activated carbon of the activated carbon filter 36. Further, as in the case of the embodiment of FIG. 1, carbon monoxide undergoes an oxidation reaction by coming into contact with the catalyst filter 31, is decomposed into carbon dioxide and H ₂ O, and is discharged from the air outlet 30 to the outside of the system. . In the embodiment of FIG. 5, the air to be treated is dehumidified by the dehumidifier 11, so that the catalyst filter 31
Not only that, the adsorption efficiency of the activated carbon filter 36 for adsorbing the malodorous component is stable, and there is an advantage that the adsorption efficiency can be prevented from significantly decreasing due to the humidity of the treated air.

Next, when the heater 37 is operated and hot air is generated after a lapse of a predetermined time from the start of the operation of the apparatus,
The organic malodorous component adsorbed on the activated carbon of the activated carbon filter 36 is desorbed from the adsorbent and is oxidized and decomposed by the catalyst filter 31. Thus, according to the embodiment shown in FIG. 5, not only carbon monoxide but also organic malodorous components and the like can be removed.

It is needless to say that the above-mentioned embodiments are merely preferable specific examples, and various design changes can be made without changing the gist of the present invention.

[0023]

As described above, according to the first aspect of the present invention.
According to the harmful gas removing apparatus of the present invention, since the air to be treated introduced into the apparatus body is dehumidified by the dehumidifier, it is possible to prevent the reactivity of carbon monoxide by the catalyst from decreasing. Particularly, in the dehumidifier used in the present invention, since the whole or part of the wall surface of the condenser pipe is formed of a water vapor permeable film, the dehumidifying action of compressing and condensing air and discharging the condensed water as a drain is performed. With the action of removing the water vapor through the water vapor permeable membrane, the dehumidification can be performed efficiently. Therefore, according to the harmful gas removing apparatus of the first aspect, it is possible to remove carbon monoxide even when the air to be treated has high humidity.

Further, according to the harmful gas removing device of the second aspect, it is possible to remove exhaust gas such as formaldehyde, acetaldehyde, acetone, acrolein and other organic malodorous components and harmful substances such as carbon monoxide to clean the exhaust gas. it can.

[Brief description of drawings]

FIG. 1 is a schematic diagram of piping of a harmful gas removing device according to an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view of a dehumidifier used in the embodiment of FIG.

3 is a cross-sectional view of the dehumidifier of FIG.

FIG. 4 is a partially cutaway plan view of a catalyst filter used in the embodiment of FIG.

FIG. 5 is a schematic diagram of piping of a harmful gas removing device according to another embodiment of the present invention.

[Explanation of symbols]

10 Device body 11 dehumidifier 16 Air pump (pressurizing means) 21 Condensing tube 22 Water vapor permeable membrane 31 Catalytic filter 36 Activated carbon filter (adsorption filter) 37 PTC heater

Claims (2)

[Claims] 1. A harmful gas removing device for removing harmful substances of the air to be treated introduced into the device body (10) by a filter mechanism (31, 36, 37), which is introduced into the device body (10). At least the wall surface of the condensing pipe (21), and the condensing pipe (21) for condensing moisture from the pressurized air to be treated to obtain dehumidified air. A harmful deodorizer characterized by being provided with a water vapor permeable membrane (22) forming a part thereof and a dehumidifier (11) for dehumidifying the air to be treated supplied to the filter mechanism (31, 36, 37). Gas removal device. 2. The filter mechanism (31) (36) (37) is disposed on the upstream side of the catalyst filter (31) for oxidizing carbon monoxide and the catalyst filter (31) to adsorb a malodorous component. The harmful substance according to claim 1, further comprising: an adsorption filter (36) filled with an adsorbent that can be regenerated by heating, and a heater (37) that heats the adsorbent from the treated air introduction side of the adsorption filter (36). Gas removal device.