JP3961639B2 - Hazardous gas purification apparatus and method having a buffer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas purification device that purifies harmful gas by heating a harmful gas containing various harmful components and malodorous components and then passing it through a catalyst.
[0002]
[Prior art]
Toxic gases containing toxic and malodorous components such as ethylene oxide gas used for sterilization treatment in hospitals, carbon monoxide and hydrocarbons discharged from combustion devices and organic solvent drying devices, It is necessary to carry out purification to remove these harmful components and malodorous components before they are released into the atmosphere. As a method of purifying such harmful gases, there is a method of passing an oxidation catalyst. If an oxidation catalyst is used, the oxidation reaction of ethylene oxide gas, carbon monoxide, hydrocarbons, etc. can be promoted and converted to harmless carbon dioxide or water vapor at a lower temperature (200 to 400 ° C.) than in the case of direct combustion. .
[0003]
Such a gas purification device is limited in the amount of harmful gas components (hereinafter referred to as processing capacity) that can be purified per unit time in accordance with the amount of the catalyst incorporated. If harmful gas exceeding the upper limit of the processing capacity is supplied to the purification apparatus, the harmful gas is exhausted without being sufficiently purified. Therefore, when using this type of gas purification apparatus, it is important not to exceed the processing capacity of the purification apparatus even if the supply amount of harmful gas components is temporary.
[0004]
[Problems to be solved by the invention]
However, noxious gases are not always generated in a constant amount and concentration, but rather there are usually considerable variations in the generation amount and concentration. Depending on the source, harmful gases are often generated intermittently. On the other hand, it is uneconomical in terms of the cost of the apparatus and the occupied space to install the purification apparatus having the processing capacity to cover the peak amount of harmful gas whose generation amount and concentration fluctuate.
[0005]
Therefore, it is considered to provide a buffer device that smoothes the amount and concentration of the harmful gas that varies in this way as much as possible, that is, reduces the variation before supplying the purification device. The simplest example of such a buffer could be to use a variable volume container such as a plastic bag. In this case, the generated harmful gas is once stored in a plastic bag, and is supplied to the purification device by a substantially constant amount by the action of a suction fan of the purification device.
[0006]
However, if a variable volume container is used as a buffer, fluctuations in the amount of harmful gas supplied can be reduced, but the concentration of harmful gas, that is, the concentration of harmful components contained in the harmful gas (components to be purified) can be reduced. The fluctuation cannot be suppressed. In addition, the plastic bag is inexpensive, but requires a considerable size in order to provide a sufficient buffering effect. Therefore, the installation space becomes large and the installation method is difficult. In order to ensure safety, it is considered that a double structure in which a plastic bag is accommodated in an outer box having a certain degree of mechanical strength is required, and there may be no merit in terms of cost.
[0007]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a buffered purification device capable of economically and safely purifying harmful gases when the amount or concentration of harmful gases fluctuates. And
[0008]
[Means for Solving the Problems]
The harmful gas purification device of the present invention is a purification device for a gas containing a harmful gas component, and adsorbs a harmful gas component in a gas by supplying a gas supply path containing a harmful gas component, a clean air introduction path, and the adsorption. A buffer including a medium capable of discharging the component, a purification unit that removes harmful gas components in the gas, a first bypass that can directly introduce the gas into the purification unit without passing through the buffer, and the cleaning A second bypass path capable of directly introducing air into the purification unit without passing through the buffer, the supply path connected to one end of the buffer, the introduction path connected to the other end, and the supply path and Each of the first bypass path and the second bypass path branches from the introduction path, and both the bypass paths merge to be connected to the purification unit. The buffer medium adsorbs the harmful gas component when the concentration of the harmful gas component contained in the supplied gas is high, and releases the harmful gas component adsorbed so far when the concentration is low. Therefore, even if the supply amount or concentration of the harmful gas varies, the harmful gas supplied to the purification unit through the buffer can be purified economically and efficiently because the concentration variation of the harmful gas component is suppressed. In addition, it is possible to flexibly cope with both the case where the concentration of the harmful gas varies and the case where the harmful gas is intermittently supplied. Furthermore, when harmful gas is generated intermittently, the concentration fluctuation of the harmful gas component diluted with clean air can be suppressed as much as possible and supplied to the purification unit.
[0009]
In addition, the harmful gas purification apparatus according to the present invention includes a first supply path for supplying a gas containing a harmful gas component, a second supply path for supplying a gas containing clean air, and purification for removing the harmful gas component in the gas. And a buffer including a medium capable of adsorbing harmful gas components in the gas and releasing the adsorbed harmful gas components, wherein the first supply path and the second supply path are each at one end. The connecting portion is connected to the purifying portion, and the first supply path and the second supply path have a first branch portion and a second branch portion, respectively. The branching section and the second branching section are connected via the buffer.
[0010]
The purification apparatus of the present invention further includes a valve, and the valve , The first bypass path and the second bypass path In It is preferable that they are arranged. By providing the valve, the mode for supplying the harmful gas to the purification unit via the buffer and the mode for directly supplying the harmful gas to the purification unit by bypassing the buffer are switched according to the supply amount and concentration of the harmful gas. be able to.
[0011]
In the purification apparatus of the present invention, the purification device further includes a concentration sensor that detects a concentration of a harmful gas component in the gas, and a valve control unit that controls opening and closing of the valve based on the detected concentration of the concentration sensor, the concentration sensor comprising: It is preferable to arrange in the supply path. By further providing such a configuration, for example, when the concentration of harmful gas is low and there is no possibility of exceeding the processing capacity of the purification unit, the buffer can be bypassed and the harmful gas can be directly supplied to the purification unit.
[0012]
In the purification apparatus of the present invention, when the valve is disposed at least in the first bypass path and the second bypass path, and the concentration detected by the concentration sensor is lower than a threshold value, the gas is When the path directly reaching the purification section through the first bypass path is selected, the valve disposed in the first bypass path is opened by the valve control means, and when the concentration is higher than the threshold value, the gas is A means for selecting a path through the buffer to the purification section, closing a valve disposed in the first bypass path by the valve control means, and opening a valve disposed in the second bypass path; It is preferable. By further providing such a configuration, when the concentration of harmful gas is high, after reducing the concentration of harmful gas through the buffer, it is combined with clean air as necessary and supplied to the purification unit. When it is low or during a period when no harmful gas (gas) is supplied, it is possible to release the harmful gas through the buffer and then join the harmful gas and supply it to the purification unit.
[0013]
In the purification apparatus of the present invention, when the valve is further disposed in the introduction path, and the path through which the gas directly reaches the purification section is selected, the valve disposed in the introduction path is opened by the valve control means, And it is preferable to close the valve arrange | positioned at the said 2nd bypass.
[0014]
That is, in the above structure, it is preferable that the clean air merges into the gas supply path through the buffer when the path through which the gas passes directly through the bypass path to the purification unit is selected. Alternatively, it is preferable to introduce clean air into the buffer when no gas is supplied, discharge the harmful gas, and then supply it to the purification unit through a harmful gas bypass.
[0015]
The purification apparatus of the present invention further includes a heater, the heater is disposed in at least one of the supply path and the introduction path, and heats at least one of the gas and the clean air by the heater, By supplying, it is preferable to promote the release of harmful gas components adsorbed on the medium. It is also preferable to promote the release of harmful gas components adsorbed in the buffer by providing a heater in the clean air introduction path and supplying the heated clean air to the buffer.
[0016]
In the purification apparatus of the present invention, the purification unit is a purification unit that purifies harmful gas components using a catalyst, and a temperature sensor that measures a temperature change of the catalyst accompanying purification of the harmful gas components, and It is preferable to further include a heating control means for controlling the heating amount of the heater based on the temperature measured by the temperature sensor. For example, the heating control means suppresses the release of harmful gas components from the buffer by stopping or reducing the heating by the heater when the temperature detected by the temperature sensor exceeds a threshold value. Since the catalyst generates heat with the purifying action, it is possible to detect that there is no margin in the purifying capacity by detecting the temperature rise.
[0017]
In the purification apparatus of the present invention, the apparatus further comprises clean air introduction control means for controlling the introduction amount of clean air based on the measured temperature of the temperature sensor, and the clean air introduction control It is preferable that the means is arranged in the introduction path. Thereby, discharge | release of the harmful | toxic gas component from a buffer can also be suppressed by controlling the introduction amount of clean air based on the detection temperature of a temperature sensor. In this case, it is preferable to further cool the catalyst by further providing another air inlet immediately before the purification unit to ensure the air volume of the air containing harmful gas supplied to the catalyst.
[0018]
Next, a method for purifying a gas containing a harmful gas component according to the present invention uses a buffer including a medium capable of adsorbing the harmful gas component in the gas and releasing the adsorbed harmful gas component, and purified air. A method for purifying a gas containing a harmful gas component for controlling the concentration of harmful gas components in the gas, and then purifying the gas in the purifying unit, wherein the gas and clean air are introduced into the purifying unit, respectively. A path is selected as a path to be introduced into the purifying section via the buffer or a path to be introduced into the purifying section without passing through the buffer, and in the buffer, the clean air is introduced into the gas containing the harmful gas. It is characterized by being introduced in the opposite direction.
[0019]
In the purification method of the present invention, the gas is purified by a catalyst, a temperature change of the catalyst accompanying the gas purification is detected, and release of harmful gas components adsorbed on the medium based on the temperature change Is preferably controlled. For example, the temperature of the catalyst that rises with the purification of harmful gas components is detected, and based on the detected information (for example, if the temperature of the catalyst becomes higher than a threshold value), the harmful gas adsorbed on the buffer medium It is preferable to suppress the release of.
[0020]
In the purification method of the present invention, it is preferable to promote the release of harmful gas components adsorbed on the medium by introducing the clean air into the buffer. In addition, it is preferable to promote the release of the harmful gas component adsorbed on the medium by heating the clean air or a gas having a low concentration of the harmful gas component and introducing it into the buffer.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention And reference embodiments Is described based on the drawings.
( reference Embodiment 1)
Figure 1 reference 1 shows a schematic configuration of a purification device according to a first embodiment. In FIG. 1, 1 is a harmful gas supply path, 2 is a pump inserted into the supply path, 3 is a buffer containing a medium 4 that once adsorbs the harmful gas components, and later releases the adsorbed components, and 5 is a harmful gas. It is a purification part which incorporates the oxidation catalyst 6 which purifies the gas. As the medium 4, for example, a material obtained by washing activated carbon with an acid to reduce the catalytic ability can be used. Reference numeral 7 denotes a bypass passage for bypassing the buffer 3 to directly introduce harmful gas into the purification section, and an on-off valve 8 is provided in the middle thereof.
[0022]
When the on-off valve 8 is closed, a harmful gas, for example, a gas containing ethylene oxide, sucked by the pump 2 and supplied through the supply path 1 is introduced into the buffer 3 and passes through the medium 4 mounted therein. To do. At this time, if the concentration of the harmful gas component (ethylene oxide) is high, a part of the component is adsorbed by the medium (activated carbon) 4, and the gas having a reduced concentration of the harmful gas component comes out of the buffer 3 and enters the purification unit 5. be introduced. The harmful gas component is almost completely purified by the oxidation catalyst 6 built in the purification unit 5 and discharged.
[0023]
On the other hand, when the concentration of the harmful gas introduced into the buffer 3 is low, the harmful gas component that has been adsorbed on the medium 4 until then is released, and the gas having a high concentration of the harmful gas component exits from the buffer 3. It is introduced into the purification unit 5. Therefore, when the concentration of harmful gas component (ethylene oxide) in the supplied harmful gas varies greatly with time, the buffer 3 containing the medium (activated carbon) 4 that repeatedly adsorbs and releases the harmful gas component is harmful. Variations in the gas component concentration are averaged, and the concentration peak is reduced and supplied to the purification unit 5.
[0024]
The processing capacity per unit time of the oxidation catalyst 6 incorporated in the purification unit 5 is limited, and when the concentration of the harmful gas supplied varies, the concentration peak does not exceed the processing capacity of the oxidation catalyst 6. It is necessary to make it. Book reference According to the embodiment, since the concentration peak of the harmful gas to be supplied is reduced by the buffer 3 as described above, the oxidation catalyst having a small processing capacity can be made in time as compared with the case where the buffer 3 is not provided. Therefore, it is possible to achieve downsizing and cost reduction of the purification device.
[0025]
An experimental result of adsorption and release (also referred to as desorption) of ethylene oxide (ethylene oxide), which is a harmful gas, using activated carbon washed with an acid as the buffer medium 4 will be described. First, a harmful gas containing 20% (200,000 ppm) of ethylene oxide and mostly other carbon dioxide was supplied to the medium 4 in the buffer 3 at a flow rate of about 10 liters / minute for about 5 minutes. At this time, the ethylene oxide concentration in the gas exiting the buffer was reduced to 8,000 to 15,000 ppm. Therefore, it was confirmed that most of the ethylene oxide component was adsorbed on the activated carbon. In addition, when the temperature of the buffer inlet part was 14-24 degreeC, the temperature of the buffer center part became 30-35 degreeC by the temperature rise by adsorption | suction of activated carbon.
[0026]
Next, the supply of harmful gas was stopped, and instead air was supplied to the buffer 3 at a flow rate of 10 liters per minute or more for about 3 hours. At this time, the gas exiting the buffer contained ethylene oxide at a concentration of 5,000 to 7,500 ppm. Therefore, it was confirmed that the ethylene oxide adsorbed by the medium 4 in the buffer 3 was released into the supplied air. In addition, the temperature of the buffer inlet part and the center part at this time was 15-30 degreeC.
[0027]
It was confirmed that the supply of harmful gas and the supply of air were repeated alternately about 20 times as described above, and the adsorption and release of ethylene oxide by the medium (activated carbon) 4 in the buffer 3 were repeated. In this experiment, a mixed gas of ethylene oxide and carbon dioxide was used as a harmful gas, and air was supplied to release harmful gas components adsorbed on the medium. reference The embodiment will be effective when the harmful gas supplied is pre-diluted with air. An embodiment in which clean air is introduced into the medium as it is and the harmful gas components are released from the medium as described above will be described later.
[0028]
In FIG. 1, when the on-off valve 8 is opened, a part of the supplied harmful gas is directly introduced into the purification unit 5 through the bypass path, and the rest is introduced into the purification unit 5 through the buffer 3. When the concentration of the harmful gas supplied is low, or when the concentration fluctuation is small and the concentration peak does not exceed the purification capacity of the oxidation catalyst 6, the on-off valve 8 can be opened to introduce the harmful gas directly into the purification unit 5.
[0029]
( reference Embodiment 2)
above reference As a modification of the embodiment, as shown in FIG. 2, a concentration sensor 9 for detecting the concentration of harmful gas components is provided in the harmful gas supply path 1, and the opening / closing control of the on-off valve 8 is performed based on the detected information. An apparatus 10 may be provided. For example, if the concentration of the harmful gas component detected by the concentration sensor 9 is low and does not exceed the treatment capacity of the oxidation catalyst 6 of the purification unit 5 continues for a predetermined time, the control device 10 opens the on-off valve 8 and is harmful. A part of the gas can be directly introduced into the purification unit 5. If a valve capable of adjusting the flow rate is used as the on-off valve 8, the ratio between the flow rate of harmful gas that passes through the buffer 3 and the flow rate that is bypassed can be changed.
[0030]
( reference Embodiment 3)
reference As another modification of the first embodiment, as shown in FIG. 3, a clean air introduction path 11 may be provided separately from the harmful gas supply path 1. The clean air introduction path 11 is provided with a pump 12 and an on-off valve 13. this reference The embodiment assumes a case where harmful gas is intermittently supplied to the harmful gas supply path 1, and the harmful gas supply path 1 is not provided with a pump. Further, the bypass path of the buffer 3 is omitted.
[0031]
this reference In the embodiment, the on-off valve 13 is closed and the pump 12 is stopped during the period when the harmful gas is supplied. Hazardous gas supplied reference As described in the first embodiment, the concentration of harmful gas components is reduced through the medium 4 in the buffer 3 and then supplied to the purification unit 5. During the period when no harmful gas is supplied, the on-off valve 13 is opened, the pump 12 is operated, and clean air is introduced from the introduction path 11 and supplied to the buffer 3. As a result, the harmful gas component that has been adsorbed by the medium 4 is released and introduced into the purification unit 5.
[0032]
So this reference The embodiment is effective when an amount of harmful gas exceeding the purification capacity of the oxidation catalyst 6 in the purification unit 5 is intermittently supplied. Even in such a case, since the concentration of the harmful gas is reduced by the adsorption action of the harmful gas component by the medium 4 in the buffer 3 and supplied to the purification unit 5, the processing is smaller than that in the case where the buffer 3 is not provided. You will be in time with the capacity of oxidation catalyst. The harmful gas component adsorbed on the medium 4 can be gradually released by introducing clean air during a period in which the intermittently supplied harmful gas is not supplied.
[0033]
(Embodiment 4)
FIG. 4 shows a schematic configuration of a purification device according to Embodiment 4 of the present invention. This embodiment 4 is shown in FIG. reference As shown in Embodiment 1 and FIG. reference The same constituent elements as those in the third embodiment are included, and the same reference numerals are given to the respective constituent elements. This Embodiment 4 is reference As in the third embodiment, a clean air introduction path 11 is provided, and a pump 12 and an on-off valve 13 are provided in the introduction path 11.
[0034]
However, as can be seen from FIG. 4, the direction in which the clean air introduced from the introduction path 11 passes through the buffer 3 is opposite to the direction in which the harmful gas introduced into the supply path 1 passes through the buffer 3. That is, the side opposite to the side connected to the harmful gas supply path 1 of the buffer 3 is connected to the clean air introduction path 11. A bypass path 15 is provided in which clean air bypasses the buffer 3 and directly reaches the purification section 5, and the bypass path 15 and the harmful gas bypass path 7 merge to communicate with the purification section 5. An on-off valve 16 is provided in the clean air bypass 15.
[0035]
In the purification apparatus of the present embodiment, when the concentration of the harmful gas is changed by the on / off control of the on-off valves 8 and 16 provided in the harmful gas bypass passage 7 and the clean air bypass passage 15, respectively, It is possible to flexibly cope with both cases of intermittent supply.
[0036]
For example, FIG. 4 shows a state in which the on / off valve 8 of the harmful gas bypass passage 7 is closed and the on / off valve 16 of the clean air bypass passage 15 is opened. In this state, the harmful gas supplied to the supply path 1 passes through the buffer 3, passes through the clean air bypass path 15, and reaches the purification unit 5. Normally, this mode is used when the concentration of harmful gas is high and the harmful gas component is adsorbed by the medium 4 through the buffer 3 and is supplied to the purification unit 5 by reducing the concentration of harmful gas component in the gas. .
[0037]
In FIG. 4, the on-off valve 13 of the clean air introduction path is closed, and therefore the pump 12 is stopped. If the on-off valve 13 is opened from this state and the pump 12 is operated, clean air is supplied from the introduction path 11 and merges with the harmful gas that has passed through the buffer 3, and the mixed gas passes through the bypass path 15 and is purified. 5 is supplied.
[0038]
FIG. 5 shows a state in which the on-off valve 8 of the harmful gas bypass passage 7 is opened and the on-off valve 16 of the clean air bypass passage 15 is closed, contrary to FIG. Further, the open / close valve 13 of the clean air introduction path 11 is opened, and the pump 12 is operated. In this state, the clean air supplied to the introduction path 11 passes through the buffer 3 to release harmful gas components adsorbed by the medium 4 in the buffer 3, and then is supplied to the purification unit 6 through the bypass path 7. Is done.
[0039]
Therefore, this mode is used when the harmful gas is intermittently supplied and the harmful gas component is released from the medium 4 in the buffer 3 during the period when the harmful gas is not supplied to the supply path 1. The Alternatively, this mode can also be used when the concentration of harmful gas supplied to the supply path 1 is low. In this case, air containing harmful gas components that have passed through the buffer 3 and released from the medium 4 is supplied. The mixed gas is supplied to the purifying section 5 through the bypass path 7 by joining with the harmful gas supplied to the path 1.
[0040]
In FIG. 5, when the on-off valve 13 of the clean air introduction path 11 is closed and the pump 12 is stopped, the harmful gas supplied to the supply path 1 is only supplied to the purification unit 5 through the bypass path 7. It becomes. This is shown in FIG. reference The mode is the same as that described in the first embodiment. Therefore, also in this embodiment, it demonstrated using FIG. reference Similarly to the second embodiment, a concentration sensor that detects the concentration of the harmful gas component may be provided in the harmful gas supply path 1, and a control device that performs opening / closing control of the on-off valve 8 based on the detection information may be provided.
[0041]
In FIG. 5, a mode in which the open / close valve 16 of the clean air bypass 15 is opened is also conceivable. In this case, a part of the clean air supplied to the introduction path 11 passes through the buffer 3 and joins the harmful gas supply path 1, and the remaining clean air passes through the bypass path 15 and the harmful gas coming from the bypass path 7. To be supplied to the purifying unit 5. As described above, the purification apparatus of the present embodiment is further provided in the clean air introduction path 11 by opening / closing control of the on-off valves 8 and 16 provided in the harmful gas bypass path 7 and the clean air bypass path 15, respectively. In combination with the control of the pump 12 and the on-off valve 13, a variety of operation modes can be switched. Therefore, it can cope with many cases including the case where the concentration of the harmful gas changes and the case where the harmful gas is intermittently supplied.
[0042]
(Embodiment 5)
As a modification of the embodiment shown in FIG. 5, in the fifth embodiment of the present invention shown in FIG. 6, a heating chamber 19 having a peter 18 is inserted in the clean air introduction path 11. The clean air supplied to the introduction path 11 is heated by the heater 18 and then supplied to the buffer 3. By introducing clean air heated to increase the temperature into the medium 4, the release of harmful gas components adsorbed on the medium is promoted.
[0043]
Instead of or in addition to the heater that heats clean air, a heater may be provided in the supply path 1 for harmful gases. In this case, the release of the harmful gas component adsorbed by the medium is promoted by heating the low concentration harmful gas and then supplying it to the buffer.
[0044]
(Embodiment 6)
FIG. 7 shows a schematic configuration of a purification device according to Embodiment 6 of the present invention. In this embodiment, a temperature sensor 20 that detects the temperature of the oxidation catalyst 6 and a control device 21 that controls energization of the heater 18 based on the detection information are added to the configuration of the fifth embodiment shown in FIG. ing.
[0045]
As described in the fifth embodiment, by supplying clean air to the buffer 3 by heating it with a heater, the harmful gas adsorbed by the medium 4 in the buffer 3 as compared with the case of supplying clean air at room temperature. The rate of component release can be increased. However, as a result of promoting the release of harmful gas components from the medium 4, there is a possibility that harmful gas having a concentration exceeding the purification capacity of the oxidation catalyst 6 in the purification unit 5 may be supplied to the oxidation catalyst 6. In particular, when air containing harmful gas components that have passed through the buffer 3 joins harmful gas from the introduction path 1 and is supplied to the purification unit, the possibility increases. Oxidation catalyst 6 self-heats due to its chemical properties as it purifies harmful gas components. Therefore, if the temperature rise of the oxidation catalyst is monitored, it can be determined whether or not there is a margin with respect to the upper limit of the processing capacity.
[0046]
Therefore, the control device 21 of the present embodiment controls the heating amount of the heater 18 based on the temperature of the oxidation catalyst detected by the temperature sensor 20. For example, when the temperature detected by the temperature sensor 20 exceeds a threshold value, the control device 21 suppresses the release of harmful gas components from the buffer by stopping or reducing the heating by the heater 18. Control of the heating amount of the heater is usually performed by changing the duty ratio (ratio of energization time per unit time). Alternatively, the heater may be controlled to stop energization when the temperature rise value within a predetermined time exceeds a threshold value.
[0047]
(Other embodiments)
FIG. Reference embodiments shown in In FIG. Illustrated embodiment As a modification of the above, a temperature sensor that detects the temperature of the oxidation catalyst 6 and a control device that controls the capacity of the pump 12 based on the detection information may be provided. By changing the amount of clean air introduced by controlling the capacity of the pump 12, the amount of harmful components released from the medium 4 in the buffer 3 can be changed. For example, when the temperature of the oxidation catalyst 6 becomes too high, the amount of harmful components supplied to the purification unit 5 may be reduced by reducing the amount of clean air introduced.
[0048]
In FIG. 3, the buffer 3 and the purification unit 5 are directly connected. However, a separate air introduction port is provided by separating this, and the introduced air is mixed with the harmful gas supplied from the buffer 3 to purify the purification unit 5. You may make it supply to. Similarly, in FIG. 4, another air inlet can be provided between the junction of the bypass paths 7 and 15 and the purification unit 5. In this way, even if the flow rate of harmful gas decreases, cooling of the oxidation catalyst 6 in the purification unit 5 can be promoted by introducing sufficient air from the air inlet immediately before the purification unit 5. A constant speed fan may be provided between the air inlet and the purifying unit 5 in order to maintain a constant air volume of the mixed gas of harmful gas and air supplied to the oxidation catalyst.
[0049]
In carrying out the present invention, the above embodiments may be combined. Various other changes may be made in addition to the above embodiment. Further, the present invention can be widely applied to purification devices for harmful gases discharged from various combustion devices and organic solvent drying devices, in addition to the purification device for ethylene oxide gas.
[0050]
【The invention's effect】
As described above, the gas purification apparatus according to the present invention includes a buffer that uses a medium that once adsorbs a harmful gas component and later releases the adsorbed component, so that the generation amount or concentration of the harmful gas varies. In addition, the purification of harmful gases can be carried out economically and safely.
[Brief description of the drawings]
[Figure 1] reference The figure which shows schematic structure of the purification apparatus which concerns on Embodiment 1.
[Figure 2] reference The figure which shows schematic structure of the purification apparatus which concerns on Embodiment 2.
[Fig. 3] reference The figure which shows schematic structure of the purification apparatus which concerns on Embodiment 3.
FIG. 4 is a diagram showing a schematic configuration of a purification device according to Embodiment 4 of the present invention.
5 is a diagram showing another operation mode of the purification device of FIG. 4;
FIG. 6 is a diagram showing a schematic configuration of a purification device according to a fifth embodiment of the present invention.
FIG. 7 is a diagram showing a schematic configuration of a purification device according to a sixth embodiment of the present invention.
[Explanation of symbols]
1 Hazardous gas supply path
2,12 pump
3 buffers
4 Buffer media
5 Purification Department
6 Oxidation catalyst
7,15 Bypass
8, 13, 16 On-off valve
9 Gas concentration sensor
10, 21 Control device
11 Clean air introduction path
18 Heater
19 Heating chamber
20 Temperature sensor

Claims (14)

A device for purifying gas containing harmful gas components,
Gas supply path containing harmful gas components,
Clean air introduction path,
A buffer comprising a medium capable of adsorbing harmful gas components in the gas and releasing the adsorbed components;
A purification unit for removing harmful gas components in the gas,
A first bypass passage capable of directly introducing the gas into the purification unit without passing through the buffer; and
A second bypass path capable of directly introducing the clean air into the purification unit without passing through the buffer;
The supply path is connected to one end of the buffer, the introduction path is connected to the other end, and the first bypass path and the second bypass path are branched from the supply path and the introduction path, respectively. A purification device in which the bypass passages join together and are connected to the purification unit. Further comprising a valve, said valve, said first bypass path and purification apparatus according to claim 1, wherein disposed in the second bypass passage.   Further, the apparatus includes a concentration sensor that detects a concentration of a harmful gas component in the gas, and valve control means that controls opening and closing of the valve based on a detected concentration of the concentration sensor, and the concentration sensor is disposed in the supply path. The purification apparatus according to claim 2. The valve is disposed at least in the first bypass path and the second bypass path;
When the concentration detected by the concentration sensor is lower than a threshold value, the gas selects a route that directly passes through the first bypass passage and reaches the purification unit, and is arranged in the first bypass passage by the valve control means. Open the valve,
When the concentration is higher than a threshold value, a path through which the gas passes through the buffer to the purification section is selected, a valve disposed in the first bypass path is closed by the valve control means, and the second The purification apparatus according to claim 3, further comprising means for opening a valve disposed in the bypass path.   When the valve is further disposed in the introduction path, and a path through which the gas directly reaches the purification section is selected, the valve disposed in the introduction path is opened by the valve control means, and the second bypass is provided. The purification device according to claim 4, wherein a valve disposed in the passage is closed.   The medium further includes a heater, and the heater is disposed in at least one of the supply path and the introduction path, and heats at least one of the gas and the clean air by the heater and supplies the gas to the buffer. The purification device according to claim 1, which promotes the release of harmful gas components adsorbed on the surface. The purification unit is a purification unit that purifies harmful gas components using a catalyst,
The purification apparatus according to claim 6, further comprising a temperature sensor that measures a temperature change of the catalyst accompanying the purification of the harmful gas component, and a heating control unit that controls a heating amount of the heater based on a temperature measured by the temperature sensor. . The purifier according to claim 7, further comprising clean air introduction control means for controlling an introduction amount of clean air based on a temperature measured by the temperature sensor, wherein the clean air introduction control means is disposed in the introduction path.   The purification apparatus according to claim 8, further comprising an air introduction port, wherein the air introduction port is formed immediately before the purification unit. A device for purifying gas containing harmful gas components,
A first supply path for supplying a gas containing a harmful gas component;
A second supply path for supplying a gas containing clean air;
A purification unit for removing harmful gas components in the gas, and
A buffer comprising a medium capable of adsorbing harmful gas components in the gas and releasing the adsorbed harmful gas components;
The first supply path and the second supply path are connected to each other at one end, the connection portion is connected to the purification unit, and the first supply path and the second supply path are respectively The purification apparatus which has a 1st branch part and a 2nd branch part, and the said 1st branch part and the 2nd branch part are connected through the said buffer. The concentration of the harmful gas component in the gas to be purified is controlled by using a buffer having a medium capable of adsorbing the harmful gas component in the gas and releasing the adsorbed harmful gas component, and clean air, and then the purification unit A method for purifying a gas containing a harmful gas component for purifying the gas,
A path for introducing each of the gas and the clean air into the purification unit is selected as a path for introducing into the purification unit via the buffer or a path for introducing into the purification unit without passing through the buffer. A purification method for introducing the clean air in a direction opposite to a direction in which a gas containing the harmful gas is introduced.   The purification of the gas is performed by a catalyst, a temperature change of the catalyst accompanying the purification of the gas is detected, and release of harmful gas components adsorbed on the medium is controlled based on the temperature change. Purification method.   The purification method according to claim 12, wherein by introducing the clean air into the buffer, release of harmful gas components adsorbed on the medium is promoted.   The purification method according to claim 12 or 13, wherein release of the harmful gas component adsorbed on the medium is promoted by heating the clean air or a gas having a low concentration of the harmful gas component and introducing the gas into the buffer.

Images