JP3286160B2 - Gas purifier using catalyst - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas purifying apparatus for purifying a harmful gas by heating a harmful gas containing various harmful components and malodorous components and then passing it through a catalyst.

[0002]

2. Description of the Related Art Harmful components and odorous components such as ethylene oxide gas used for sterilization treatment in hospitals, or carbon monoxide and hydrocarbons discharged from a combustion device or a drying device for organic solvents are used. It is necessary to purify the contained harmful gases to remove these harmful components and odorous components before releasing them to the atmosphere. As a method of purifying such harmful gas,
There is a method of passing through an oxidation catalyst. If an oxidation catalyst is used, the oxidation reaction of ethylene oxide gas, carbon monoxide, hydrocarbons, etc. can be promoted at lower temperatures (200 to 400 ° C.) than in the case of direct combustion, and can be changed to harmless carbon dioxide or water vapor. .

FIG. 1 shows a conventional example of a gas purifier using a catalyst of this kind. In the figure, 1 is a wall of the purification chamber, 2 is a heater,
Reference numeral 3 denotes an oxidation catalyst, and 4 denotes a blower fan. The harmful gas sucked by the blower fan 4 is heated by the heater 2 at a predetermined temperature (2
After being heated to the temperature of about 0.00 to 400 ° C.), it is purified through the oxidation catalyst 3 and discharged.

[0004]

When the concentration of the harmful gas introduced into the above gas purifier is high or the oxygen concentration is low, the harmful gas is completely purified by mixing air (or oxygen). It is necessary to secure enough oxygen. Further, since the catalyst has resistance to the passage of the gas, the harmful gas pushed by the fan or the like may leak out of the device before passing through the catalyst, and may lower the purification efficiency.

Further, the gas that has passed through the catalyst is considerably higher than normal temperature, and may not be able to be exhausted as it is. In such a case, it is necessary to exhaust the air after cooling to some extent, for example, by mixing with air at room temperature. In addition, since the temperature of the wall of the purification chamber filled with the gas heated by the heater becomes high, if the wall cannot be exposed, it is necessary to surround the wall with a heat insulating material such as glass wool. For these reasons, the entire purification device tends to be large.

Further, an oxidation catalyst using a noble metal such as platinum is generally expensive, and the size of an oxidation catalyst that can be used is naturally limited in terms of cost. The demand for downsizing of the apparatus also limits the size of the oxidation catalyst. For this reason, the amount of gas that can be purified per unit time is limited. Therefore, when the amount of generated harmful gas fluctuates, even if the amount of harmful gas exceeding the processing capacity is temporarily supplied to the oxidation catalyst, there is a possibility that unpurified harmful gas is mixed and discharged. is there.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a compact and high-performance gas purifying apparatus.

[0008]

In order to achieve the above object, a first configuration of a gas purifying apparatus according to the present invention comprises a first passage having a harmful gas introduction passage and a blower communicating with the harmful gas introduction passage. A second chamber having a heating means (heater) and a catalyst in communication with the first chamber and a third chamber surrounding part or all of the periphery of the second chamber and communicating with the first chamber; Room and
A fourth chamber surrounding the first, second and third chambers and having an outside air inlet and an outlet, wherein the harmful gas introduced from the introduction path is sent to the heater by the blowing means, After being heated by the heater, the catalyst is discharged through the catalyst, and the air entering from the outside air intake of the fourth chamber flows outside the first, second, and third chambers. And the first and third chambers are under negative pressure with respect to the fourth chamber.
It is characterized by becoming .

According to this structure, the third and fourth chambers are located around the second chamber, which is heated to a high temperature by the heating means, and fresh air entering the fourth chamber from the outside air inlet is provided. Flows outside the first, second and third chambers, this air flow provides an insulating effect between the hot chamber and the outer wall of the purification device. Further, the third chamber is a buffer chamber between the second chamber and the fourth chamber. Therefore, the outer wall surface does not become too hot, although the purifier is small as a whole.

Since the first and third chambers have a negative pressure with respect to the fourth chamber, the second chamber, the third chamber, and the fourth chamber are not sealed. Even so, it is possible to prevent the harmful gas from leaking from the first and third chambers to the fourth chamber. Therefore, for example, the mounting structure of the heater installed inside the second chamber and the connection structure of the lead wires can be simplified.

The air entering the fourth chamber from the outside air inlet enters the first chamber directly or via the third chamber, and is sent to the second chamber while being mixed with the introduced harmful gas. Even when the concentration of the harmful gas to be introduced is high or the oxygen concentration is low, the amount of oxygen that can completely purify the harmful gas is ensured. In addition, the harmful gas leaked from the second chamber to the third chamber before passing through the catalyst is returned to the first chamber, thereby preventing unpurified gas from leaking out of the apparatus, and purifying the gas. Efficiency can be kept high.

The air entering the fourth chamber from the outside air inlet is:
In addition to being used for heat insulation and mixing with harmful gases as described above, it can also be used for diluting purified hot gas. That is, the air that enters from the outside air inlet of the fourth chamber and flows outside the first, second, and third chambers and the gas that has passed through the catalyst are mixed and discharged from the outlet. Is preferred. In this way, the purified hot gas is diluted by being mixed with fresh air and effectively cooled. In this case, a second air blowing means is provided near the outlet of the fourth chamber, and the air blowing means sucks and mixes the air entering from the outside air inlet and the gas passing through the catalyst, and then mixes the air. Preferably, it is configured to discharge from the outlet. And the second
By using a sirocco fan as the air blowing means,
It is easy to adopt a structure for exhausting gas to a predetermined exhaust pipe through a relatively small outlet. Thus, for example, instead of exhausting the air into the room, the air can be exhausted outside through the exhaust pipe.

[0013] A second aspect of the gas purifying apparatus according to the present invention comprises a variable volume container having an inlet and an outlet for gas, and a flow valve connected to the outlet of the container for restricting a flow rate.
Or has a drive to deliver gas at a constant flow rate
And a flow control device connected to the harmful gas introduction path. For example, a plastic (vinyl) bag can be used as the variable volume container .

[0014]

FIG. 2 shows a schematic configuration of a gas purifying apparatus according to an embodiment of the present invention. This device is for purifying ethylene oxide gas (hereinafter, referred to as "harmful gas") used for sterilization treatment in hospitals and the like, and includes a device main body 11, a gas reservoir container 12, an air pump 13, a gas introduction pipe. 14, an exhaust pipe 15 and the like.

The apparatus body 11 is, for example, 300 × 300 × 5
It has a rectangular parallelepiped shape of 00 mm, one end face is the outside air intake 11a, and the other end face is closed.
A gas introduction pipe 14 is connected to a side surface (upper surface in FIG. 2) near the outside air intake 11a, and an exhaust pipe 15 is connected to a side surface near a closed end surface. Reference numeral 16 denotes an insulating cord for supplying a current to a heater housed therein.

The gas reservoir 12 and the air pump 13 inserted in the middle of the gas introduction pipe 14 temporarily store the harmful gas discharged intermittently from the sterilizer or the like, and supply the harmful gas to the purifier main body 11 by a fixed amount. belongs to. Therefore, it is preferable that the volume of the gas reservoir container 12 changes in accordance with the amount of the harmful gas supplied intermittently. As a simple matter, a plastic bag (plastic bag) can be used. A container having a structure like a bellows may be used. The air pump 13 as the flow control device only needs to obtain a substantially constant flow rate, and does not need to perform accurate flow control. Therefore, a fan can be used instead. Alternatively, it may be a simple flow control valve, in which case,
The driving force for sending the harmful gas into the apparatus body 11 is the apparatus body 1
The suction means built in 1 will take charge.

FIG. 3 shows the internal structure of the apparatus main body 11 as viewed from the side. FIG. 4 shows an internal structure of the apparatus main body 11 as viewed from above. The harmful gas introduced into the apparatus main body 11 from the gas introduction pipe 14 first enters a first chamber 18 having a fan 17 which is a blowing means, and is sent into a second chamber 19 by the fan 17. The second chamber 19 is provided with a heater 20 as a heating means and an oxidation catalyst 21. Second
The harmful gas sent to the chamber 19 of the
After being heated to a temperature of about 0 to 400 ° C., the oxidation catalyst 2
Purified through one.

Both ends of the heater 20 are fixed to the upper wall of the second chamber 19 by insulating terminals, and are drawn out of the apparatus main body 11 by the insulating cord 16. And the second room 1
A third chamber 22 surrounding the upper wall 9 and communicating with the first chamber 18 is provided. The oxidation catalyst 21 is, for example, a block-shaped catalyst in which a noble metal such as platinum or palladium is supported on a carrier mainly composed of calcium aluminate, and this is used as an outlet of the second chamber 19, that is, a fourth chamber 23. It is arranged at the communication port with.

The fourth chamber 23 is a space formed by the outer walls of the first, second and third chambers 18, 19, 22 and the outer wall of the apparatus main body 11. The box forming the first, second and third chambers 18, 19, 22 is supported on the bottom surface of the apparatus main body 11 by four columns 24. Note that FIG.
In these, these struts are omitted. The fourth chamber 23 is provided with a sirocco fan 25 as a second blowing means, and the gas purified through the oxidation catalyst 21 is sucked by the sirocco fan 25 and the exhaust pipe 1 serving as an outlet is provided.
Exhausted from 5

The opposite side of the fourth chamber 23 (the outside air inlet 11a)
An air filter 26 is provided on the side), and the air sucked by the sirocco fan 25 is introduced into the fourth chamber 23 through the air filter 26. The introduced air flows outside the first, second and third chambers 18, 19, 22 and reaches the sirocco fan 25. On the other hand, the gas purified through the oxidation catalyst 21 is also sucked by the sirocco fan 25 and introduced into the fourth chamber 23. At this time, the oxidation catalyst 2
The temperature of the high-temperature gas that has passed through 1 is reduced by being mixed with and diluted with the air introduced from the outside air inlet 11a, so that high-temperature deterioration of the sirocco fan 25 and the exhaust pipe 15 is avoided. Also, safety of the exhaust gas is ensured.

In the above configuration, the third chamber 22
Is heated in the second chamber 19 which is heated by the heater 20.
And a fourth chamber 23. Furthermore, the third room 2
The static pressure efficiency of the fan 17 provided in the first chamber communicating with the second chamber 2 is set larger than the static pressure efficiency of the sirocco fan 25 provided in the fourth chamber 23. That is, the static pressure efficiencies of the two fans are set such that the first and third chambers 18 and 22 have a negative pressure with respect to the fourth chamber 23. Therefore, for example, even when the attachment portion of the heater 20 and the lead wire fixing portion are not sealed, it is possible to prevent the harmful gas from leaking from the first and third chambers 18 and 22 to the fourth chamber 23. Can be prevented.

The fourth chamber 23 is connected to the outside air inlet 11a.
The air introduced into the first, second and third chambers 18, 1
By flowing outside 9, 22, this air flow provides an insulating effect between the hot chamber and the outer wall of the purifier. Therefore, although the purifying device main body 11 is small, the outer wall surface does not become very hot.

Further, a communication hole 27 is provided in a partition wall between the first chamber 18 and the fourth chamber, and a part of the air introduced into the fourth chamber 23 passes through the communication hole 27 and passes through the communication hole 27. Room 1 18
Will be introduced. As a result, even in the case of a harmful gas having a high concentration (or a case of a low oxygen concentration), an oxygen amount capable of completely purifying the harmful gas is secured. However, the communication hole 27 does not necessarily need to be provided positively, and may be replaced by a gap formed in the partition structure between the first chamber 18 and the fourth chamber. Further, a part of the air introduced into the fourth chamber 23 is not directly introduced into the first chamber 18,
It may be configured to be introduced into the first chamber 18 via the third chamber 22.

In the above embodiment, the third chamber 18
Is provided so as to surround only the upper portion of the second chamber 19, but a third chamber may be provided so as to also surround the side surface of the second chamber 19 and also surround the bottom surface. Further, the end face of the apparatus main body 11 opposite to the outside air inlet 11a is closed and a small exhaust port (exhaust pipe 15) is provided on the side face. However, the present invention is not limited to such a configuration. For example, an axial fan may be provided instead of the sirocco fan 25 with all or a part of the end face serving as an exhaust port.

In practicing the present invention, various other changes can be made to the specific configuration of the above embodiment. In addition, the present invention can be widely applied to, for example, an apparatus for purifying harmful gases discharged from various combustion apparatuses and an organic solvent drying apparatus, in addition to an ethylene oxide gas purifying apparatus.

[0026]

As described above, the gas purifying apparatus according to the present invention divides the inside of the apparatus body into a plurality of chambers, and appropriately controls the flow and mixing of the introduced harmful gas and fresh air. A high heat insulation effect and a high purification rate can be obtained, and the size of the device can be reduced. By using the introduced air for heat insulation and mixing with the harmful gas, and further for diluting the purified high-temperature gas, a more safe and efficient purification device can be obtained.

Further, by providing a variable-volume container as a buffer in the introduction path of the harmful gas and providing a flow control device at the outlet of the container, the harmful gas discharged intermittently is once stored and gradually ( (A fixed amount at a time) can be supplied to the purification device main body, so even if the amount of harmful gas exceeding the processing capacity of the catalyst is generated temporarily, the harmful gas exceeding the processing capacity per unit time of the catalyst By preventing supply to the catalyst, harmful gases can be reliably purified.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a conventional gas purification device.

FIG. 2 is an external view showing the entire gas purification device according to the embodiment of the present invention.

FIG. 3 is a side view showing the inside of the main body of the gas purification device of FIG. 2;

FIG. 4 is a top view showing the inside of the main body of the gas purification device of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Main body 11a Outside air intake 12 Gas reservoir 13 Air pump 14 Gas introduction pipe 15 Exhaust pipe 16 Heater lead wire 17, 25 Fan 18 First chamber 19 Second chamber 20 Heater 21 Oxidation catalyst 22 Third chamber 23 Third 4 room 24 prop 26 air filter 27 communication hole

Claims (8)

(57) [Claims] 1. A gas purifying apparatus for purifying a harmful gas by heating the harmful gas and passing the harmful gas through a catalyst, comprising: a harmful gas introduction path; and a first chamber communicating with the harmful gas and having a blowing means. A second chamber communicating with the first chamber and having a heating means and a catalyst; a third chamber surrounding part or all of the periphery of the second chamber and communicating with the first chamber; A fourth chamber surrounding the outside of the first, second and third chambers and having an outside air inlet and an outlet, wherein the harmful gas introduced from the introduction path is sent to the heater by the blowing means, while it is discharged through said catalyst after being heated by the heater, and the air entering from the outside air inlet of the fourth chamber is configured to flow outside of the first, second and third chamber , The first and third chambers are
A gas purifying apparatus using a catalyst which has a negative pressure with respect to chamber 4 . 2. The air entering the fourth chamber from the outside air inlet.
Directly into the first chamber via the third chamber,
The waste gas is sent to the second chamber while being mixed with the harmful gas.
A gas purification device using the catalyst described in the above . 3. The method according to claim 1, wherein the second chamber is removed from the second chamber before passing through the catalyst.
The harmful gas leaked to the third chamber is returned to the first chamber.
Item 2. A gas purifier using the catalyst according to Item 1 . 4. The first and the fourth chambers enter through an outside air inlet of a fourth chamber.
Air flowing outside the second and third chambers and passing through the catalyst
Mixed with the exhaust gas and discharged from the outlet
The gas purifying apparatus using the catalyst according to any one of claims 1 to 3, wherein the gas purifying apparatus comprises: 5. A second blower near the outlet of the fourth chamber.
Means is provided, and the air blowing means enters through the outside air intake.
Air and gas passing through the catalyst are sucked and mixed
After exiting the outlet, the
A gas purification device using the catalyst according to claim 4 . 6. A gas purifying apparatus using a catalyst according to claim 5 , wherein the second blowing means is a sirocco fan . 7. A method for heating a harmful gas and passing it through a catalyst.
Gas purifier that purifies harmful gases.
A container of variable volume having a mouth and an outlet, the outlet of the container
A flow valve that restricts the flow rate connected to the
Harmful gas is connected to the variable volume container and the flow valve
Through the heating means and the catalyst.
Gas purifier using a known catalyst. 8. A gas purifying apparatus for purifying a harmful gas by heating the harmful gas and passing it through a catalyst, wherein the vessel has a variable volume container having an inlet and an outlet for the gas, and is connected to an outlet of the container. Drive unit for delivering gas at a constant flow rate
And a catalyst configured to be connected to the introduction path of the harmful gas, and the harmful gas is introduced into the heating means and the catalyst through the variable volume container and the flow control device. Gas purification device.