JP2007105657A - Gas treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a gas treatment apparatus treating exhaust gas containing an organic solvent. <P>SOLUTION: Exhaust gas containing organic solvent gas is introduced to this gas treatment apparatus through a pipe 4, treated to contain substantially no organic solvent gas in the exhaust gas, and discharged to the atmosphere through a pipe 5. An adsorption apparatus 1 is connected to an adsorption apparatus 2 via a valve 7 through a valve 21 by pipes. The adsorption apparatuses 1, 2 are connected to a desorption means 3. By disposing an adsorption apparatus having finished a desorption action after an adsorption apparatus in an absorption action, even if the concentration of the exhaust gas of the preceding adsorption apparatus becomes high, it can be removed by the latter adsorption apparatus. Thus, a required amount of an adsorbent can be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas processing apparatus for removing harmful substances such as organic solvents contained in exhaust gas. In particular, the present invention relates to an apparatus for removing VOC from exhaust gas generated from a source that emits exhaust gas containing a volatile organic compound (VOC) that is a cause of air pollution.

  Conventionally, this type of gas processing apparatus employs a method of processing with an end-of-pipe of a local exhaust apparatus installed at a generation source.

  In this method, ambient air is simultaneously sucked in by local exhaust, so it is necessary to treat exhaust gas with a relatively low concentration. Adsorption / concentration with an adsorbent such as activated carbon and zeolite, and a method of treating the gas after concentration are used. It is often done. Treatment methods include liquefaction recovery by cooling condensation and decomposition by combustion / catalytic combustion.

For example, an organic solvent gas is adsorbed with an adsorbent such as activated carbon or zeolite, and the gas substantially free of organic solvent after adsorption is released to the atmosphere. When the adsorbent is saturated with an organic solvent, it is desorbed and regenerated using heat and pressure. In addition, there is known a method in which a concentrated gas of a desorbed organic solvent is cooled, liquefied and recovered (for example, Patent Document 1).

  Hereinafter, the exhaust gas treatment apparatus will be described with reference to FIG.

  As shown in the figure, a conventional exhaust gas treatment apparatus 101 comprises an adsorbing means 102 for adsorbing an organic solvent gas, a desorbing means 103 for desorbing the adsorbed organic solvent gas, and a liquefying means 104 for liquefying the desorbed organic solvent gas. ing. The adsorbing means 102 includes an adsorbent such as activated carbon or zeolite, and adsorbs and removes the organic solvent in the exhaust gas. The breakthrough of the adsorbent is predicted or detected, the organic solvent is desorbed by the desorption means 103, and the adsorbent is regenerated. Here, the desorption means 103 uses a vacuum pump and desorbs the organic solvent by reducing the pressure.

The desorbed organic solvent gas is sent to the liquefying means 104, cooled and liquefied. The uncondensed gas that has passed through the liquefying means 104 is exhausted as it is or returned to the adsorbent again.
Japanese Patent Laid-Open No. 11-71584

  In such an exhaust gas treatment device, the amount of adsorbent used is reduced, the treatment means such as liquefaction and combustion are miniaturized, the device is miniaturized, and the organic solvent gas in the exhaust gas is reliably removed. For example, the concentration is required to be equal to or lower than the concentration regulation value of the exhaust gas.

  However, in the conventional gas processing apparatus, a large amount of adsorbent for adsorption and concentration is required to cope with the air volume of the local exhaust apparatus, and the apparatus has been enlarged.

  Also, when switching the adsorption device from adsorption to desorption, the concentration of the exhaust gas is reduced below the regulation value, so desorption operation must be performed even though adsorption is still possible, and the adsorption capacity of the adsorbent is fully used. It was not possible, and a larger amount of adsorbent was required.

  Moreover, the concentration of the desorption gas is lowered, and the efficiency of liquefaction and decomposition in the subsequent process is not good.

  Further, there is a possibility that high concentration gas is discharged when the adsorption device is switched.

  The present invention solves such a conventional problem, and by arranging a plurality of adsorption devices in series, the amount of adsorbent to be used is reduced and the size is reduced, and a concentrated gas having a high concentration is also provided. The object is to supply a gas treatment apparatus capable of increasing the concentration.

  Also, exhaust gas with high concentration is prevented when switching between adsorption operation and desorption operation, and a small and low-priced exhaust gas treatment device is supplied, and organic solvent gas in the exhaust gas is reliably removed to prevent atmospheric emission. The purpose is to do.

  In order to achieve the above object, the exhaust gas treatment apparatus of the present invention desorbs gas components adsorbed from a plurality of adsorbers having an adsorbent that adsorbs gas components in the air that alternately perform adsorption and desorption. A desorbing means for performing an adsorption operation, allowing the air containing the gas component to pass through an adsorbing device that performs an adsorbing operation, adsorbing the gas component to the adsorbent in the adsorbing device, and releasing air that does not substantially contain the gas component. On the other hand, a gas processing device for removing gas components in the air, which can desorb gas components adsorbed by the adsorbent in the adsorbing device, regenerate the adsorbent, and obtain a concentrated gas component. , A plurality of adsorption devices that perform the adsorption operation are arranged in series to adsorb the gas components in the air, and are switched to desorption in order from the adsorption device at the most inlet side, and desorption is performed by the desorption means, and the desorption operation is completed. The device is intended disposed downstream of the suction device disposed in the plurality series. By this means, it is possible to prevent the discharge of high-concentration exhaust gas when switching from adsorption to desorption, and to increase the amount of gas component adsorbed to the adsorbent, so that the gas component can be removed reliably and adsorbed. The amount of the agent can be reduced, and a small and inexpensive gas processing apparatus can be provided.

  Another means is that a gas component in the air is a volatile organic solvent. By this means, it is possible to provide an exhaust gas treatment apparatus that can reliably remove the organic solvent gas in the exhaust gas.

  Further, the other means includes two adsorption devices, a first adsorption device and a second adsorption device, and the second adsorption device in which the desorption operation is completed while the first adsorption device is performing the adsorption operation is the first adsorption device. The first adsorption device is arranged in series at the subsequent stage of the first adsorption device, and the adsorption operation is performed. Next, the first adsorption device is switched to the desorption operation, and the desorption operation is performed. When the desorption operation of the first adsorbing device is completed, the adsorbing operation is performed in series with the subsequent stage of the second adsorbing device, and thereafter, the above operation is repeated. By this means, it is possible to prevent the discharge of high-concentration exhaust gas when switching from adsorption to desorption with two adsorption devices, and to increase the amount of adsorption of the gas component to the adsorbent. In addition to being able to be removed, the amount of adsorbent can be reduced, and a small and inexpensive gas processing apparatus can be provided.

  The other means switches the adsorption operation to the desorption operation after the adsorbent breakthrough. This means that the amount of gas components adsorbed on the adsorbent during the adsorption operation can be increased, so that a concentrated gas with a high concentration can be obtained, and the amount of the adsorbent can be reduced and the gas can be reduced in size and price. A processing device can be provided.

  In addition, the other means performs switching from the adsorption operation to the desorption operation in a preset time, and can stabilize the amount of adsorption of the gas component to the adsorbent during the adsorption operation. Thus, a concentrated gas with a high concentration can be obtained, and the amount of adsorbent can be reduced to provide a small and inexpensive gas processing apparatus.

  The other means includes breakthrough detection means for detecting breakthrough of the adsorbent, and switches the adsorption device from the adsorption operation to the desorption operation by the output of the breakthrough detection means. By this means, since the breakthrough of the adsorbent is detected even if the gas component concentration of the exhaust gas fluctuates, the adsorption amount of the gas component to the adsorbent during the adsorption operation can be stabilized, so that the A concentrated gas having a high concentration can be obtained, and the amount of adsorbent can be reduced to provide a small and inexpensive gas processing apparatus.

  Further, the other means includes a gas concentration measuring means for measuring the concentration of the gas component on the outlet side of the adsorption device as the breakthrough detection means, and detects the breakthrough of the adsorption device by the output of the gas concentration measurement means. The suction operation is switched to the desorption operation. By this means, since the breakthrough of the adsorbent is detected even if the gas component concentration of the exhaust gas fluctuates, the adsorption amount of the gas component to the adsorbent during the adsorption operation can be stabilized, so that the A concentrated gas having a high concentration can be obtained, and the amount of adsorbent can be reduced to provide a small and inexpensive gas processing apparatus.

  Another means uses a semiconductor gas sensor as the gas concentration measuring means. By this means, since the breakthrough of the adsorbent is detected even if the gas component concentration of the exhaust gas fluctuates, the adsorption amount of the gas component to the adsorbent during the adsorption operation can be stabilized, so that the A concentrated gas having a high concentration can be obtained, and the amount of adsorbent can be reduced to provide a small and inexpensive gas processing apparatus.

  Another means is provided with a buffer means for reducing the concentration fluctuation of the gas component in the previous stage of the adsorption apparatus. By this means, even if the gas component concentration of the exhaust gas fluctuates, the fluctuation of the gas concentration can be reduced by the buffer means, so that the amount of adsorption to the adsorbent can be stabilized, the amount of adsorbent can be reduced and the size can be reduced. An inexpensive gas processing apparatus can be provided.

  Another means uses a tank filled with an adsorbent as the buffer means. By this means, fluctuations in the gas concentration of the exhaust gas can be mitigated, so that the amount of adsorption to the adsorbent can be stabilized, and the amount of adsorbent can be reduced to provide a small and inexpensive gas processing apparatus.

  The other means uses a volatile organic solvent liquid which is a gas component to be removed as a buffer means. By this means, a stable high concentration gas can be always introduced into the adsorption device, so that it is possible to provide a gas treatment device that can increase the adsorption amount to the adsorbent and increase the concentration of the desorption gas.

  Another means is a method of bubbling with a volatile organic solvent liquid as a buffer means. By this means, a stable high concentration gas can be always introduced into the adsorption device, so that it is possible to provide a gas treatment device that can increase the adsorption amount to the adsorbent and increase the concentration of the desorption gas.

  The other means dilutes by the diluting means after passing through the buffer means. By this means, a stable high concentration gas can be always introduced into the adsorption device, so that it is possible to provide a gas treatment device that can increase the adsorption amount to the adsorbent and increase the concentration of the desorption gas.

  Another means includes a liquefaction means for liquefying the desorbed gas. By this means, it is possible to provide a small and low-priced gas processing apparatus that can liquefy and recover gas components from the exhaust gas.

  The other means includes buffer means using an organic solvent solution, and returns the liquefied organic solvent to the buffer means. By this means, it is possible to provide a gas processing apparatus that does not need to supply the organic solvent liquid to the buffer means.

  The other means is provided with a decomposition means for decomposing the desorbed gas. By this means, it is possible to provide a small and low-priced gas processing apparatus capable of removing gas components from exhaust gas, decomposing and discharging them.

  According to the present invention, it is possible to provide an exhaust gas treatment apparatus that can reduce the size of an apparatus that can reduce the amount of adsorbent without discharging high-concentration gas even when the adsorption operation and desorption operation of the adsorption device are switched.

  In addition, since the amount of gas that can be adsorbed by the adsorbent can be increased, a degassing gas can be made high in concentration, processing such as liquefaction and decomposition can be performed efficiently, and the gas processing apparatus that is effective in reducing the size of the apparatus Can be provided.

  The invention according to claim 1 of the present invention comprises a plurality of adsorption devices having an adsorbent for adsorbing gas components in the air that alternately perform adsorption and desorption, and desorption means for desorbing the gas components adsorbed from the adsorbent, Air containing the gas component is passed through an adsorbing device that performs an adsorbing operation, the gas component is adsorbed by an adsorbent in the adsorbing device, and air that does not substantially contain the gas component is released. The gas component adsorbed in the adsorbent is desorbed by a desorbing means, and the adsorbent is regenerated and a concentrated gas component can be obtained. A plurality of adsorption devices are arranged in series to adsorb gas components in the air, and the adsorption device is switched to desorption in order from the adsorption device on the most inlet side, and the adsorption devices that have been desorbed by the desorption means and completed the desorption operation are arranged in series. By arranging a plurality of adsorption devices in the adsorption operation in series, the adsorption of the gas component to the adsorbent of the adsorption device closest to the inlet proceeds and the adsorption is performed. Even if the concentration of the outlet gas of the apparatus becomes high, the exhaust gas from the gas processing apparatus can be kept at a low concentration because the next adsorption device is arranged in the subsequent stage.

  Further, since the outlet gas concentration of the adsorption device may be increased, the amount of adsorption to the adsorbent can be increased, and the adsorption device can be configured with a small amount of adsorbent, so that the apparatus can be miniaturized.

  In addition, when the adsorption device on the most inlet side is switched from the adsorption operation to the desorption operation, even if a high-concentration gas passes due to the pipe switching, the next adsorption device is arranged in the subsequent stage, so that the gas processing device Since the exhaust gas from can be kept at a low concentration, it has the effect of providing a gas processing device that can reliably remove gas components.

  The invention according to claim 3 of the present invention comprises two adsorption devices, a first adsorption device and a second adsorption device, and the second adsorption operation is completed while the first adsorption device is performing the adsorption operation. The adsorption device is arranged in series at the subsequent stage of the first adsorption device and performs an adsorption operation, and then the first adsorption device is switched to the desorption operation and desorption is performed. Next, when the desorption operation of the first adsorption device is completed, the adsorption operation is performed by arranging in series at the subsequent stage of the second adsorption device, and thereafter the above operation is repeated. Adsorption of gas components to the adsorbent of the preceding adsorption device by arranging the adsorption device that has completed the desorption operation when performing the adsorption operation using the device in series in the subsequent stage of the adsorption device already performing the adsorption operation Even if the concentration of the outlet gas of the adsorption device increases, Due to the arrangement of the following adsorber, exhaust gas from the gas treatment device can be kept low concentrations. In addition, when switching the adsorption device in the previous stage from the adsorption operation to the desorption operation, even if a high concentration gas passes due to the pipe switching, the next adsorption device is arranged in the subsequent stage. Since the exhaust gas can be kept at a low concentration, it has the effect of providing a gas processing device that can reliably remove gas components.

  Further, the invention according to claim 4 of the present invention is such that switching from the adsorption operation to the desorption operation is performed after breakthrough of the adsorbent, and the adsorbent of the adsorption device continues adsorption even after breakthrough, Since the amount of the gas component adsorbed on the adsorbent can be increased and the adsorber can be configured with a small amount of adsorbent, the apparatus can be downsized and the concentration of desorbed gas can be increased.

  In the invention according to claim 5 of the present invention, switching from the adsorption operation to the desorption operation is performed in a preset time, and the adsorption operation amount of the gas component can be sufficiently secured during the adsorption operation. By setting the time in advance and switching periodically, it is possible to obtain stable gas component removal performance and stabilize the concentration of the desorbed gas gas component.

  The invention described in claim 6 is provided with breakthrough detection means for detecting breakthrough of the adsorbent, and the adsorption device is switched from the adsorption operation to the desorption operation by the output of the breakthrough detection means. Yes, by detecting the breakthrough of the adsorbent, the amount of gas component adsorbed on the adsorbent of the adsorber can be stabilized even if the gas component concentration of the exhaust gas introduced by the gas treatment device fluctuates. It is not necessary to use more adsorbent than necessary, and the adsorber can be configured with a small amount of adsorbent, so that the apparatus can be miniaturized and the variation in the concentration of gas components in the desorbed gas can be reduced.

  Further, the invention according to claim 7 of the present invention is provided with gas concentration measuring means for measuring the concentration of the gas component on the outlet side of the adsorption device as breakthrough detecting means, and the breakthrough of the adsorption device is detected by the gas concentration measuring means. Is detected and switched from adsorption operation to desorption operation, and the adsorbent breakthrough is detected by measuring the concentration of the outlet gas of the adsorption device. Since the amount of gas components adsorbed to the adsorbent of the adsorption device can be stabilized even if the gas component concentration of the exhaust gas introduced by the gas treatment device fluctuates, an excessive amount of adsorbent is used for safety. Since there is no need and the adsorption device can be configured with a small amount of adsorbent, it is possible to reduce the size of the device and to reduce variations in the gas component concentration of the desorption gas.

  The invention according to claim 8 of the present invention uses a semiconductor type gas sensor as the gas concentration measuring means. Since the semiconductor type gas sensor is relatively small and inexpensive, the apparatus can be reduced in size and price. Has an effect.

  Further, the invention according to claim 9 of the present invention is provided with a buffer means for reducing the concentration fluctuation of the gas component in the previous stage of the adsorption device, and the gas component concentration of the exhaust gas introduced into the gas processing device is changed by the buffer means. However, since the fluctuation can be reduced by the buffer means, the amount of gas components adsorbed to the adsorbent of the adsorption device can be stabilized, so there is no need to use more adsorbent than necessary, and a small amount of adsorption is required. Since the adsorbing device can be configured with an agent, the device can be miniaturized, and it has the effect of reducing variations in the gas component concentration of the desorption gas.

  The invention according to claim 10 of the present invention uses a tank filled with an adsorbent as a buffer means, and mitigates fluctuations in the concentration of gas components in the exhaust gas introduced by the gas treatment device due to the absorption / release characteristics of the adsorbent. Since the amount of gas components adsorbed on the adsorbent of the adsorption device can be stabilized with a small volume, it is not necessary to use more adsorbent for safety, and the adsorption device is configured with a small amount of adsorbent. Therefore, the apparatus can be miniaturized, and the variation in the gas component concentration of the desorption gas can be reduced.

  The invention according to claim 11 of the present invention uses a volatile organic solvent liquid that is a gas component to be removed as a buffer means, and the exhaust gas introduced into the gas processing apparatus by volatilization of the volatile organic solvent. Since the gas component concentration can be increased to reduce fluctuations, the amount of adsorption to the adsorbent can be increased, and it is not necessary to use more adsorbent for safety, and adsorption is performed with a small amount of adsorbent. Since the apparatus can be configured, the apparatus can be downsized, and the gas component concentration of the desorption gas can be increased to reduce the variation.

  Further, the invention according to claim 12 of the present invention is a method of bubbling with a volatile organic solvent liquid as a buffer means, and by bubbling the exhaust gas introduced by the gas processing apparatus with a volatile organic solvent liquid, Since the amount of gas components adsorbed to the adsorbent of the adsorption device can be stabilized with a small volume, there is no need to use more adsorbent than necessary for safety, and a small amount Since the adsorbing device can be configured with this adsorbent, the size of the device can be reduced, and the gas component concentration of the desorption gas can be increased to reduce the variation.

  Further, the invention according to claim 13 of the present invention is to dilute by the diluting means after passing through the buffer means, and the concentration can be adjusted by diluting by relaxing the fluctuation of the gas concentration introduced into the adsorption device. Since the amount of gas components adsorbed on the adsorbent of the adsorber can be stabilized, it is not necessary to use more adsorbent than necessary, and the adsorber can be configured with a small amount of adsorbent. The gas component concentration of the gas can be increased to reduce the variation.

  Further, the invention according to claim 14 of the present invention is provided with a liquefying means for liquefying the desorbed gas, and has an effect that the desorbed gas is liquefied to recover the organic solvent liquid so that it can be reused.

  The invention described in claim 15 includes buffer means using an organic solvent solution, and returns the liquefied organic solvent to the buffer means. The supply of the organic solvent liquid to the buffer means is circulated in the apparatus. And has the effect of being able to drive.

  The invention according to claim 16 of the present invention is provided with a decomposing means for decomposing the desorbed gas, and is capable of decomposing the desorbed gas and releasing a substantially harmless gas into the atmosphere. The device can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of the exhaust gas treatment apparatus of the present invention.

  As shown in the figure, exhaust gas containing organic solvent gas discharged from facilities using organic solvents such as painting, printing, industrial cleaning, etc. is introduced into the gas processing apparatus from the pipe 4 and the organic solvent gas in the exhaust gas from the pipe 5 Is removed to a state that does not substantially contain, and is discharged into the atmosphere. The adsorption device 1 and the adsorption device 2 are connected by piping from the valve 7 through the valve 21. In the figure, the adsorption operation piping is indicated by a solid line, and the desorption operation piping is indicated by a dotted line. Here, adsorbents such as activated carbon, zeolite, alumina, and silica gel capable of adsorbing a target organic solvent gas as adsorbents are carried on adsorbents 1 and 2 on a granular, pellet, or honeycomb substrate. Filled in shape. A desorption means 3 is connected to the adsorption device 1 and the adsorption device 2. Here, as long as the desorption means 3 can desorb the organic solvent adsorbed on the adsorbent, the known method can be used. For example, as a method for desorbing by heating the adsorbent, there are heating the adsorbent, sending heated air, sending steam heated by a boiler, etc., and as a method for desorbing by pressure, a vacuum pump There are a method of depressurizing the atmosphere of the adsorbent and further desorbing by flowing purge air and a method of heating it. Here, the case where the desorption operation by depressurization is performed using the desorption means 3 as a vacuum pump will be described.

  The operation of the gas processing apparatus configured as described above will be described with reference to FIGS.

  FIG. 2 is a block diagram illustrating a state in which the adsorption device 1 performs an adsorption operation and the adsorption device 2 performs a desorption operation. In the figure, the used piping system is indicated by a thick line, the open valve is indicated by white, and the closed valve is indicated by black.

  Exhaust gas containing an organic solvent gas introduced from the pipe 4 by a blower such as a fan or a blower enters the adsorption device 1 through a valve 9. In the adsorption device 1, the organic solvent in the exhaust gas is adsorbed and removed by the adsorbent. The exhaust gas that has passed through the adsorption device 1 passes through the valve 8 and the valve 7 and is released from the pipe 5 into the atmosphere substantially free of organic solvent gas.

  At the same time, the adsorption device 2 performs a desorption operation. The adsorption device 2 is depressurized to a pressure of about several kPa through the valve 17 by the vacuum pump of the desorption means 3, and the valve 12 is Purge air for detachment is introduced through this. The organic solvent adsorbed on the adsorbent of the adsorbing device 2 is desorbed from the adsorbent by depressurization and purge air and supplied to the next processing step, for example, liquefaction or decomposition, etc. from the pipe 6 as a gas containing a high concentration organic solvent. Is done.

  When the desorption of the organic solvent adsorbed on the adsorbent of the adsorption device 2 is completed, the operation proceeds to the next operation.

  FIG. 3 is a block diagram showing a state in which the adsorption device 1 and the adsorption device 2 are performing an adsorption operation as an operation subsequent to the operation shown in FIG.

  As shown in the figure, exhaust gas containing an organic solvent gas introduced from a pipe 4 by a blower such as a fan or blower enters the adsorption device 1 through a valve 9. In the adsorption device 1, the organic solvent in the exhaust gas is adsorbed and removed by the adsorbent. The exhaust gas that has passed through the adsorption device 1 is introduced into the adsorption device 2 via the valve 8, the valve 11, the valve 20, and the valve 18, and the adsorption device 2 also adsorbs and removes the organic solvent in the exhaust gas using the adsorbent. 14 and the valve 15 are released into the atmosphere substantially free of organic solvent gas.

  Here, the suction device 1 performs the suction operation continuously from the operation shown in FIG. Therefore, the adsorbent gradually approaches breakthrough and the outlet gas concentration of the adsorption device 1 becomes higher. However, since the adsorption device 2 is connected at the subsequent stage, the gas discharged from the gas processing device is substantially reduced. The state which does not contain organic solvent gas can be maintained. This operation is continued until a sufficient amount of adsorbent is adsorbed on the adsorbent of the adsorption device 1.

  FIG. 4 is a block diagram showing a state where the adsorption device 1 is performing a desorption operation and the adsorption device 2 is performing an adsorption operation. When the adsorbent of the adsorption device 1 sufficiently adsorbs the organic solvent by the operation shown in FIG. 3, the exhaust gas containing the organic solvent gas introduced from the pipe 4 by a blower such as a fan or blower is passed through the valve 19 and the valve 18. The organic solvent in the exhaust gas is adsorbed and removed by the adsorbent introduced into the adsorbing device 2, and the exhaust gas passing through the adsorbing device 2 becomes substantially free of organic solvent gas from the pipe 5 through the valve 14 and the valve 15. Released into the atmosphere. The adsorption device 1 is switched to the desorption operation, and is depressurized to a pressure of about several kPa through the valve 16 by the vacuum pump of the desorption means 3, and the purge air for desorption is introduced from the pipe 22 through the valve 10. Yes. The organic solvent adsorbed on the adsorbent of the adsorbing device 1 is desorbed from the adsorbent by depressurization and purge air, and is supplied as a gas containing a high concentration organic solvent from the pipe 6 to the next processing step, for example, liquefaction or decomposition. Is done.

  When the desorption of the organic solvent adsorbed on the adsorbent of the adsorption device 1 is completed, the operation proceeds to the next operation.

  FIG. 5 is a block diagram showing a state in which the adsorption device 2 and the adsorption device 1 are performing an adsorption operation.

  In the figure, exhaust gas containing organic solvent gas introduced from a pipe 4 by a blower such as a fan or blower is introduced into the adsorption device 2 through a valve 19 and a valve 18 and adsorbs and removes the organic solvent in the exhaust gas by the adsorbent. The exhaust gas that has passed through the adsorption device 2 is introduced into the adsorption device 1 through the valve 14, the valve 13, and the valve 21. The adsorption device 1 also adsorbs and removes the organic solvent in the exhaust gas with the adsorbent, and the valve 8 and the valve 7. Through the pipe 5, the organic solvent gas is not substantially contained from the pipe 5 and is released to the atmosphere.

  Here, similarly to the operation in FIG. 3, the adsorber 2 gradually approaches the breakthrough of the adsorbent and the outlet gas concentration of the adsorber 2 becomes higher, but the adsorber 1 is connected to the subsequent stage. The gas discharged from the gas processing apparatus can maintain a state that does not substantially contain an organic solvent gas. This operation is continued until a sufficient amount of adsorbent is adsorbed to the adsorbent of the adsorption device 2, and when the adsorption of the adsorption device 2 is completed, the operation is switched to the operation of FIG. repeat.

  Here, each operation can be switched using a timer or the like according to a preset time.

  Here, the case where there are two adsorption devices has been described, but the same operation and effect can be obtained even if three or more adsorption devices are used. In this case, the adsorption device that has completed the desorption operation is disposed at the last stage of the adsorption device that is performing the adsorption operation. The last stage means the most outlet side of the adsorption device arranged in series.

  As described above, by disposing the adsorption device that has completed the desorption operation at the subsequent stage of the adsorption device that is in the adsorption operation, even if the concentration of the exhaust gas from the previous adsorption device becomes high, it is removed by the subsequent adsorption device. Can do. Therefore, the adsorption operation can be continued even after the adsorbent of the preceding adsorption device breaks through, and the adsorption amount to the adsorbent can be increased. Therefore, the amount of adsorbent used can be reduced, the concentration of desorbed gas can be increased, the apparatus can be reduced in size and price, and the organic solvent from the exhaust gas can be reliably removed. Can be provided.

(Embodiment 2)
FIG. 6 is a block diagram showing a part of the configuration of the gas processing apparatus of the present invention. The same parts as those in the first embodiment of the present invention are denoted by the same reference numerals and description thereof is omitted. In the figure, gas concentration measuring means 23 as breakthrough detecting means is connected to the outlets of the adsorption device 1 and the adsorption device 2 and measures the gas concentration. Here, the gas concentration measuring means 23 is cited as the breakthrough detection means, but any method that can detect the breakthrough of the adsorbent may be used, and methods such as the temperature measurement of the adsorbent and the weight measurement of the adsorbent may also be used. Can do.

  As the gas concentration measuring means 23, any known method can be used as long as it can measure the concentration of the target organic solvent. For example, an FID type measuring device, a PID type measuring device, an NDIR type measuring device, and the like can be given. In particular, if a semiconductor type gas sensor is used, the organic solvent gas concentration can be measured with a small and low-cost apparatus.

  In the above configuration, by measuring the outlet gas during the adsorption operation of the adsorption device 1 and the adsorption device 2 with the gas concentration measuring means 23, the adsorption amount of the organic solvent gas of the adsorbent in the adsorption device can be known. Switching to the desorption operation can be determined by setting in advance a concentration at which the adsorbent in the adsorption device sufficiently adsorbs the organic solvent gas and sufficiently removes the organic solvent gas.

  For this reason, even if the concentration of the organic solvent gas in the exhaust gas introduced into the gas treatment device fluctuates, the amount of adsorption to the adsorbent of the adsorber can be stabilized, so that the amount of adsorbent used can be reduced. In addition, the concentration of the desorption gas can be stabilized.

  Therefore, it is possible to reduce the cost by reducing the size of the apparatus, and it is possible to reliably remove the organic solvent gas.

(Embodiment 3)
7 and 8 are block diagrams showing the configuration of the gas processing apparatus of the present invention. In addition, the same number is attached | subjected to the part same as Embodiment 1, 2 of this invention, and description is abbreviate | omitted.

  In FIG. 7, the buffer means 24 introduces exhaust gas containing organic solvent gas introduced from a pipe 4 by a blower such as a fan or blower, and relaxes the concentration fluctuation to the adsorption device 1 or the adsorption device 2 during the adsorption operation. Introduce.

  Here, the buffer means 24 may be any method that can alleviate the concentration fluctuation of the introduced exhaust gas. For example, if a tank filled with an adsorbent is used, the concentration fluctuation of the exhaust gas can be mitigated by utilizing the absorption / release characteristics of the adsorbent. In this case, it is possible to configure with a relatively small capacity.

  Further, the concentration fluctuation can be alleviated by volatilizing the target organic solvent. In this case, the organic solvent concentration of the exhaust gas is increased to reduce the concentration fluctuation, and the amount of adsorption to the adsorbent of the adsorption device can be increased.

  Further, by bubbling in the target organic solvent solution, it is possible to further increase the concentration and reduce the concentration fluctuation.

  Further, as shown in FIG. 8, by connecting the diluting means 25 to the outlet of the buffer means 24, the concentration of the exhaust gas introduced into the adsorption devices 1 and 2 can be adjusted, and the concentration fluctuation can be further alleviated. it can. Here, the dilution means 25 introduces air for dilution with a blower such as a fan or a blower.

  As described above, the buffer means 24 is provided in the front stage of the adsorption device, and the amount of organic solvent gas adsorbed on the adsorbent can be stabilized by reducing the concentration fluctuation of the exhaust gas introduced into the adsorption device. The amount used can be reduced.

  Therefore, the apparatus can be downsized and the concentration of the desorbed gas can be stabilized, so that reliable gas removal can be achieved.

(Embodiment 4)
FIG. 9 is a block diagram showing the configuration of the system of the exhaust gas treatment apparatus of the present invention. In addition, the same number is attached | subjected to the part same as Embodiment 1-3 of this invention, and description is abbreviate | omitted.

  In the figure, the liquefying means 26 cools and liquefies the desorption gas containing the organic solvent gas introduced from the vacuum pump as the desorption means 3. The liquefied gas is discharged from the pipe 6. Further, the liquefied organic solvent liquid is stored in the liquid reservoir 27 and a part thereof is supplied to the buffer means 24. Here, the liquefaction means 26 performs cooling by a cooling device such as a refrigeration cycle.

  In the above configuration, by liquefying the organic solvent gas from the desorption gas by the liquefaction means, it can be recovered and reused, and when the organic solvent is used for the buffer means, the liquefied organic solvent is supplied to the buffer means. Is possible.

(Embodiment 5)
FIG. 10 is a block diagram showing the configuration of the exhaust gas treatment apparatus of the present invention. In addition, the same number is attached | subjected to the part same as Embodiment 1-4 of this invention, and description is abbreviate | omitted.

  In the figure, the decomposition means 28 decomposes the organic solvent in the desorption gas including the organic solvent gas introduced from the vacuum pump as the desorption means 3 to make it substantially harmless and releases it from the pipe 6 to the atmosphere. Here, the decomposition means 28 can use the known method as long as it can decompose the target organic solvent gas. For example, decomposition by combustion, combustion catalyst, photocatalyst, ultraviolet light, ozone, plasma decomposition, microorganism, enzyme, and the like.

  In the above configuration, by decomposing the organic solvent gas in the desorption gas by the decomposing means, the organic solvent gas in the exhaust gas can be reliably removed and released into the atmosphere in a harmless state.

  Installed in facilities that discharge volatile organic solvents, such as printing, painting, bonding, chemical product manufacturing, industrial cleaning, etc., it is useful as an exhaust gas treatment device.

The block diagram which shows the structure of Embodiment 1 of this invention. The block diagram which shows operation | movement of Embodiment 1 of this invention. The block diagram which shows operation | movement of Embodiment 1 of this invention. The block diagram which shows operation | movement of Embodiment 1 of this invention. The block diagram which shows operation | movement of Embodiment 1 of this invention. The block diagram which shows the structure of Embodiment 2 of this invention. The block diagram which shows the structure of Embodiment 3 of this invention. The block diagram which shows the structure of Embodiment 3 of this invention. The block diagram which shows the structure of Embodiment 4 of this invention. The block diagram which shows the structure of Embodiment 5 of this invention. Block diagram showing the configuration of a conventional gas recovery device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adsorber 2 Adsorber 3 Desorption means 23 Gas concentration measurement means 24 Buffer means 25 Dilution means 26 Liquefaction means 28 Decomposition means

Claims (16)

A plurality of adsorption devices having an adsorbent that adsorbs gas components in the air that alternately perform adsorption and desorption, and a desorption means that desorbs the gas components adsorbed from the adsorbent, and the gas components in the adsorption device performing an adsorption operation The gas component is adsorbed by the adsorbent in the adsorption device through the air containing the gas, the air substantially free of the gas component is released, and the gas component adsorbed by the adsorbent in the adsorption device is In a gas processing apparatus that removes gas components in the air that can be desorbed by a desorption means to regenerate the adsorbent and obtain a concentrated gas component, a plurality of adsorption devices that perform an adsorption operation are arranged in series. The adsorbing device that adsorbs the gas components in it, switches to the desorption in order from the adsorption device on the most inlet side, desorbs by the desorption means, and completes the desorption operation is arranged in the last stage of the adsorption device arranged in series Gas processing apparatus to so that. The gas processing apparatus according to claim 1, wherein the gas component in the air is a volatile organic solvent. There are two adsorption devices, a first adsorption device and a second adsorption device, and the first adsorption device is in the adsorption operation, and the second adsorption device in which the desorption operation is completed is placed in the subsequent stage of the first adsorption device. Arrange in series, perform adsorption operation, then switch the first adsorption device to desorption operation and perform desorption, during which the adsorption operation is performed by the second adsorption device, then desorption of the first adsorption device 3. The gas processing apparatus according to claim 1, wherein when the operation is completed, the adsorption operation is performed in series after the second adsorption device, and thereafter, the operation is repeated. The gas processing apparatus according to claim 1, 2 or 3, wherein the switching from the adsorption operation to the desorption operation is performed after breakthrough of the adsorbent. The gas processing apparatus according to claim 4, wherein switching from the adsorption operation to the desorption operation is performed in a preset time. The gas processing apparatus according to claim 4, further comprising breakthrough detection means for detecting breakthrough of the adsorbent, wherein the adsorption apparatus is switched from an adsorption operation to a desorption operation by an output of the breakthrough detection means. As a breakthrough detection means, a gas concentration measurement means for measuring the concentration of the gas component is provided on the outlet side of the adsorption device, and the breakthrough of the adsorption device is detected by the output of the gas concentration measurement means and switched from the adsorption operation to the desorption operation. The gas processing apparatus according to claim 4, which is configured as described above. 8. A gas processing apparatus according to claim 7, wherein a semiconductor gas sensor is used as the gas concentration measuring means. The gas processing apparatus according to claim 1, further comprising buffer means for reducing a concentration fluctuation of the gas component in a front stage of the adsorption apparatus. The gas processing apparatus according to claim 9, wherein a tank filled with an adsorbent is used as the buffer means. The gas processing apparatus according to claim 9, wherein a volatile organic solvent liquid that is a gas component to be removed is used as the buffer means. 12. The gas processing apparatus according to claim 11, wherein bubbling is performed with a volatile organic solvent liquid as the buffer means. The gas processing apparatus according to claim 11 or 12, wherein the gas processing apparatus is diluted by a dilution means after passing through the buffer means. The gas processing apparatus according to claim 1, further comprising a liquefying unit configured to liquefy the desorbed gas. 15. A gas processing apparatus according to claim 14, further comprising buffer means using an organic solvent solution, wherein the liquefied organic solvent is returned to the buffer means. The gas processing apparatus according to claim 1, further comprising a decomposing unit that decomposes the desorbed gas.

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