JPH0615017B2 - Carbon monoxide removing apparatus and control method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to removal of carbon monoxide, and more particularly to an apparatus for removing carbon monoxide in the atmosphere by a catalytic reaction and a control method thereof.

[Conventional technology]

FIG. 3 shows an example of a conventional apparatus for removing carbon monoxide in the atmosphere by a catalytic reaction. The components in the atmosphere are nitrogen,
It contains oxygen, argon, carbon dioxide, and water. Other trace impurities include carbon monoxide, hydrocarbons, sulfides, chlorides, dust, etc. Especially for carbon monoxide which is difficult to separate with an air separator because its boiling point is close to nitrogen, an air separator It had to be removed before being sent to.

In FIG. 3, the air sucked from the air suction port 1 is normally pressurized by the air compressor 2 to 5 to 8 kg / cm ² G,
It reaches a temperature of 100 ° C. and is introduced into the carbon monoxide removing device 5 via the pipe 3. A catalyst is filled in this device, and carbon monoxide reacts with oxygen in the air to be converted into carbon dioxide. The air from which carbon monoxide has been removed by the chemical reaction is sent to the next step via the outlet pipe 6. However, in such a conventional method, the catalyst is gradually poisoned by hydrocarbons, particularly heavy oils, sulfides, and chlorides contained in the atmosphere, and as a result, the reaction rate of carbon monoxide decreases. Therefore, long-term continuous operation is not possible,
In the worst case, there was a drawback that it could not function as a device within a few months. As a device related to this type, there is, for example, Japanese Patent Application Laid-Open No. 55-152517.

[Problems to be Solved by the Invention]

The above-mentioned prior art does not consider the long-term continuous operation of the apparatus, and since the entire amount of the air compressor is always introduced into the carbon monoxide removing apparatus, the apparatus cannot be continuously operated for a long term due to the catalyst poisoning substances in the atmosphere. was there.

It is an object of the present invention to provide a carbon monoxide removing apparatus and a control method therefor capable of improving continuous operation time of the apparatus by improving control of the apparatus.

[Means for Solving the Problems]

In order to achieve the above purpose, the atmospheric carbon monoxide concentration was measured throughout the year. As a result, the concentration was low in the summer and high in the winter, and the evening commuting hours in the morning. It was found that the concentration was high during the time when employees were leaving the office and low during other hours. This is because the atmosphere is stable in summer and the diffusion of carbon monoxide is good. In winter, the inversion layer of the atmosphere is apt to occur and the diffusion is poor, so the concentration varies depending on the season. Was estimated.
Moreover, it was estimated that the phenomenon that the concentration increases and decreases depending on the day is related to the traffic of cars.

Based on such measurement facts, when the concentration of carbon monoxide in the atmosphere rises, the inlet valve of the carbon monoxide removing device is opened,
By increasing the air flow rate to the equipment, and conversely, when the carbon monoxide concentration decreases, the equipment inlet valve is closed to reduce the air flow rate to the carbon monoxide removal equipment throughout the year and to poison the catalyst contained in the atmosphere. The continuous operation time of the device is improved by reducing the absolute amount of the substance flowing into the device for removing carbon monoxide.

[Work]

The valve control device operates according to the detection value of the carbon monoxide concentration analyzer provided in the atmosphere or at the outlet of the carbon monoxide removing device, and when the detection value rises, the inlet valve of the device opens and the bypass valve closes. On the contrary, when the detected value decreases, the inlet valve of the device is closed and the bypass valve is opened, so that the device can be continuously operated for a long period of time.

〔Example〕

 An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, the concentration of carbon monoxide in the air sucked through a carbon monoxide concentration analysis tube 9 installed near the air inlet 1 is measured by a carbon monoxide concentration analyzer 10. On the other hand, the air taken in through the air suction port 1 is normally pressurized to 5 to 8 kg / cm ² G by the air compressor 2,
A temperature of 0 to 100 ° C. is reached and air is sent through the pipe 3. The temperature measured by the carbon monoxide analyzer 10 is converted as a signal and connected to the valve controller 11. When the carbon monoxide concentration becomes high, the inlet valve 4 of the carbon monoxide removing device 5 is opened at the same time as the bypass valve 8 is closed by a command from the valve control device 11 without changing the flow rate of the air compressor 2. The valve is opened and closed continuously. On the contrary, as the concentration of carbon monoxide decreases, the inlet valve 4 is gradually closed and the bypass valve 8 is gradually closed according to a command from the valve controller 11.
It is controlled without changing the flow rate as a whole.

In this way, the amount of air flowing into the carbon monoxide removing device 5 is increased or decreased according to the device inlet concentration of carbon monoxide, and air is passed through the carbon monoxide removing device 5 only when necessary, so that the minimum required amount can be obtained. A limited amount of air will be vented to the device.

The carbon monoxide in the air that has flowed into the carbon monoxide removing device 5 reacts with oxygen in the air due to a catalytic effect to become carbon dioxide, which is sent through the outlet pipe 6 and passed through the bypass valve 8. After merging with, the gas is sent to the next process through the pipe 7.

The carbon monoxide concentration analysis tube 9 does not necessarily have to be in the vicinity of the air suction port 1, and, for example, as shown in FIG.
It can also be installed in the pipe 7 downstream of the confluence of the outlet pipe 6 of the carbon monoxide removing device 5 and the bypass valve 8. Also in this case, when the carbon monoxide concentration becomes high, the effect similar to that shown in FIG. 1 can be obtained by closing the inlet valve 4 of the apparatus and closing the bypass valve 8 at the same time.

According to the present embodiment, the concentration of carbon monoxide is low in the summer season, and almost all of the air can be made to flow through the bypass valve.
Since air can flow through the bypass valve except for ~ 5 hours, the following effects can be achieved.

As a ventilation ratio for carbon monoxide remover (1) As a seasonal variation, about half of one year can be completely discharged by a bypass valve 0.5 (2) As a time variation, only about 5 hours a day Therefore, according to the present invention, the amount of air vented to the device is 0.5 × 0.2 = 0.1, and the absolute amount of air vented to the carbon monoxide removing device is approximately Compared to the case without the invention, the continuous operation time of the whole system for achieving the purpose of carbon monoxide removal is about 1/10, that is, 10 times.
It can be said that this effect is very large because it can be doubled.

Although the effect of the invention is slightly different depending on the installation location of the carbon monoxide removing device, generally, an air separation device connected to the carbon monoxide removing device is often installed in an industrial area, which stabilizes the atmosphere in summer and winter, Since the instability phenomenon is similar,
It can be similar and effective.

[Advantages of the Invention] According to the present invention, the detection value of the carbon monoxide concentration in the atmosphere or at the device outlet controls the inlet valve and bypass valve of the device, and the amount of ventilation to the carbon monoxide removing device throughout the year. It is possible to continuously operate the device for a long period of time because it reduces.

[Brief description of drawings]

FIG. 1 is a schematic system diagram of a carbon monoxide removing apparatus according to an embodiment of the present invention, FIG. 2 is a schematic system diagram of a carbon monoxide removing apparatus according to another embodiment, and FIG. 3 is a conventional carbon monoxide removal apparatus. It is a schematic system diagram of a removal device. 4 ... Inlet valve, 5 ... Carbon monoxide removing device, 6 ... Outlet pipe, 8 ... Bypass valve, 9 ... Carbon monoxide concentration analysis pipe, 10
...... Carbon monoxide concentration analyzer, 11 ...... Valve control device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Tsushima 794 Azuma Higashitoyo, Kudamatsu City, Yamaguchi Prefecture Hitachi Techno Engineering Co., Ltd. Kasado Plant

Claims (2)

[Claims] 1. A carbon monoxide removing device for removing carbon monoxide in the atmosphere by a catalytic reaction, wherein a pipe passage for bypassing the carbon monoxide removing device is provided, and the bypass pipe passage and the inlet of the carbon monoxide removing device. And a valve for each of them, and configured to control each of the valves via a control device according to the detection value of the carbon monoxide concentration analyzer provided in the atmosphere or the path of the outlet pipe of the carbon monoxide removal device. A device for removing carbon monoxide. 2. A method for controlling an apparatus for removing carbon monoxide in the air by a catalytic reaction, wherein the inlet valve of the apparatus is opened when the concentration of carbon monoxide in the atmosphere or the carbon monoxide concentration at the apparatus outlet increases. By closing the bypass valve together with the device, the amount of ventilation to the device is increased. Conversely, when the concentration of carbon monoxide in the atmosphere or the concentration of carbon monoxide at the device outlet decreases, the device inlet valve is closed and the bypass A method for controlling a carbon monoxide removing device, which is characterized in that a control for reducing an air flow rate to the device is performed by opening a valve.