JP6774346B2 - Gas processing equipment - Google Patents

Description

The present invention relates to a gas treatment apparatus that purifies a gas to be treated.

Conventionally, a technique for purifying an exhaust gas by performing a high voltage discharge in the exhaust gas to create a plasma state has been known. In recent years, this technology has been applied to a purification device for purifying factory exhaust gas and an air purifier for purifying indoor air for the purpose of deodorizing.

Plasma in a thermally non-equilibrium state, that is, in a state where the electron temperature is much higher than the gas temperature or ion temperature (non-equilibrium plasma (hereinafter, simply referred to as plasma)) is an ion or radical produced by electron collision. Is considered to be useful in harmful gas treatment as a medium capable of efficiently removing or decomposing harmful gas because it promotes chemical reactions that do not occur at room temperature. The key to the practical application of this technology is to improve the energy efficiency during processing and to convert it into a completely safe product after processing with plasma.

Generally, plasma at atmospheric pressure is generated by a gas discharge or an electron beam. Nitrogen oxides (NOx), sulfur oxides (SOx), chlorofluorocarbons, and carbon dioxide (CO ₂ ) are currently being considered for application. , Volatile organic solvent (VOC), etc. Among them, NOx is contained in the exhaust gas of automobiles, so urgent practical application is required.

As a gas treatment device for purifying this type of gas, a honeycomb structure having a large number of through holes is arranged in a ventilation path, and a high voltage is applied between electrodes arranged at both ends of the honeycomb structure to form the honeycomb structure. There is a type that generates plasma in the through hole of. In this gas treatment device, the harmful gas contained in the gas to be processed passing through the through hole is decomposed into a harmless substance by the plasma generated in the through hole of the honeycomb structure (for example, Patent Document 1). reference).

In this type of gas processing apparatus, a technique for generating uniform plasma as a whole in the honeycomb structure has not been established, and the gas processing capacity becomes unstable. On the other hand, the state of plasma generation inside the honeycomb structure has a characteristic that the more water content in the gas to be treated, the more active it is, and the less water content, the more it is suppressed. That is, there is a characteristic that the gas processing capacity increases as the water content in the gas to be treated increases, and the gas processing capacity decreases as the water content decreases.

Therefore, in Patent Document 2, moisture is sent into the space between the electrode and the honeycomb structure by a humidifying device to increase the moisture concentration in the gas to be treated, activate plasma discharge, and enhance the gas processing capacity. The gas treatment device is disclosed.

Japanese Unexamined Patent Publication No. 2000-140562 Japanese Unexamined Patent Publication No. 2004-08970

However, in the technique disclosed in Patent Document 2, since the amount of water sent by the humidifier is not controlled, if the amount of water supplied is too small, the generation of plasma discharge is insufficient and the gas processing capacity is insufficient. There is a risk that by-products will be generated without completely decomposing the processing substance. If the amount of water supplied is excessive, the gas processing capacity is increased, but the discharge becomes intense, and there is a possibility that an abnormal discharge such as a spark discharge may occur. Further, if the air after the plasma treatment is supplied to the room, the humidity of the air supplied to the room becomes high, which causes a problem that the person in the room feels uncomfortable.

The present invention has been made to solve such a problem, and an object thereof is gas treatment capable of maintaining a constant humidity environment in a honeycomb structure and stabilizing a gas treatment capacity. To provide the equipment.
Another object of the present invention is to provide a gas treatment apparatus that does not cause the indoor person to feel uncomfortable due to the high humidity of the air after the plasma treatment.
In addition, a gas processing device that can reliably determine the processing load in the plasma processing unit before stabilizing the gas processing, and quickly adjust the processing capacity of the plasma processing unit to the appropriate processing capacity corresponding to the processing load. Is to provide.

In order to achieve such an object, the present invention is arranged in the ventilation passage (A) in the gas treatment apparatus (100) configured to purify the treatment target gas and output it as the processed gas, and provides the ventilation passage. The water treatment unit (1) configured to humidify the flowing treatment target gas and the treatment target gas provided on the downstream side of the ventilation path from the water treatment unit and humidified by the water treatment unit are the first gas. The treatment target gas or the treated gas before being humidified by the water treatment unit is used as the second gas, and the humidity is adjusted by mixing the first gas and the second gas. A honeycomb structure having a portion (2) and a large number of through holes (31a) provided on the downstream side of the ventilation path from the mixing portion and through which the humidity-adjusted processing target gas in the mixing portion passes as the mixing processing target gas. It has electrodes (32, 33) arranged on the upstream side and the downstream side of the honeycomb structure with respect to the body (31) and the direction in which the gas to be mixed is passed, respectively, and depends on the voltage applied between the electrodes. The absolute humidity of the plasma processing unit (3) configured to generate plasma in the through holes of the honeycomb structure and the gas to be mixed processed from the mixing unit to the plasma processing unit is measured as the first absolute humidity. The first humidity measuring unit (S1) and the gas to be mixed and processed that have passed through the plasma processing unit are treated as the treated gas, and the absolute humidity of the treated gas is measured as the second absolute humidity. The mixing ratio of the second humidity measuring unit (S2) and the mixing ratio of the first gas and the second gas in the mixing unit is controlled so that the first absolute humidity becomes the target value. It is configured to control the voltage applied between the control unit (7) and the electrodes of the plasma processing unit so that the difference between the first absolute humidity and the second absolute humidity falls within a predetermined humidity difference range. The capacity of the plasma processing unit before the control of the mixing ratio by the applied voltage control unit (8) and the mixing ratio control unit and the control of the voltage applied between the electrodes of the plasma processing unit by the applied voltage control unit are started. The mixing ratio applied voltage initial control unit configured to control the mixing ratio of the first gas and the second gas and the voltage applied between the electrodes of the plasma processing unit so as to have the maximum practical processing capacity. (6) is provided.

In the present invention, the first humidity measuring unit measures the absolute humidity of the gas to be mixed processed from the mixing unit to the plasma processing unit as the first absolute humidity (hF), and the second humidity control unit measures the plasma. The absolute humidity of the gas to be mixed and processed (processed gas) that has passed through the section is measured as the second absolute humidity (hR). In the mixing ratio control unit, the first gas (the gas to be treated humidified by the water treatment unit) and the second gas (water treatment unit) so that the first absolute humidity (hF) becomes the target value (hsp). The mixing ratio (M) with the gas to be treated or the treated gas before being humidified by is controlled. As a result, the absolute humidity (hF) of the gas to be mixed and processed from the mixing unit to the plasma processing unit is set to the target value (hsp), and the gas to be mixed to be mixed with this absolute humidity (hF) as the target value (hsp). It is sent to the plasma processing unit.

On the other hand, the applied voltage control unit sets the difference (Δh = hF−hR) between the first absolute humidity (hF) and the second absolute humidity (hR) within a predetermined humidity difference range (ΔhB ± α). In addition, the voltage (V) applied between the electrodes of the plasma processing unit is controlled.
For example, when the difference (Δh) between the first absolute humidity (hF) and the second absolute humidity (hR) is large and is out of the predetermined humidity difference range (Δh> ΔhB + α), mixing in the plasma processing unit. The voltage (V) applied between the electrodes of the plasma processing unit is controlled so as to suppress the gas processing capacity for the gas to be processed. When the gas processing capacity is suppressed, the amount of water consumed in the plasma processing unit is reduced, the second absolute humidity (hR) is increased, and the first absolute humidity (hF) and the second absolute humidity (hR) are increased. The difference (Δh) from the first absolute humidity (hF) becomes smaller, and the difference (Δh) between the first absolute humidity (hF) and the second absolute humidity (hR) falls within the predetermined humidity difference range (ΔhB ± α). Become.
For example, when the difference (Δh) between the first absolute humidity (hF) and the second absolute humidity (hR) is small and is out of the predetermined humidity difference range (Δh <ΔhB−α), the plasma processing unit is used. The voltage (V) applied between the electrodes of the plasma processing unit is controlled so as to increase the gas processing capacity for the gas to be mixed. When the gas processing capacity is increased, the amount of water consumed in the plasma processing unit increases, the second absolute humidity (hR) decreases, and the first absolute humidity (hF) and the second absolute humidity (hR) become The difference (Δh) becomes large, and the difference (Δh) between the first absolute humidity (hF) and the second absolute humidity (hR) falls within the predetermined humidity difference range (ΔhB ± α). ..

In this way, in the present invention, the mixing ratio (M) of the first gas and the second gas is controlled so that the first absolute humidity (hF) becomes the target value (hsp), and the first gas is used. The voltage (V) applied between the electrodes of the plasma processing unit so that the difference (Δh) between the absolute humidity (hF) and the second absolute humidity (hR) falls within the predetermined humidity difference range (ΔhB ± α). Is controlled. As a result, the humidity environment inside the honeycomb structure is kept constant, and the gas processing capacity can be stabilized. Further, the problem that the humidity of the air after the plasma treatment becomes high and makes the person in the room feel uncomfortable does not occur.

Further, in the present invention, the mixing ratio applied voltage initial control unit starts before the mixing ratio control unit controls the mixing ratio and the applied voltage control unit controls the voltage applied between the electrodes of the plasma processing unit. The mixing ratio of the first gas and the second gas and the voltage applied between the electrodes of the plasma processing unit are controlled so that the capacity of the plasma processing unit becomes the maximum practical processing capacity. As a result, the processing load of the plasma processing unit can be reliably obtained before stabilizing the gas processing, and the processing capacity of the plasma processing unit can be quickly adjusted to an appropriate processing capacity corresponding to the processing load.

In the above description, as an example, the components on the drawing corresponding to the components of the invention are indicated by reference numerals in parentheses.

Based on the above description, according to the present invention, the mixing ratio of the first gas and the second gas in the mixing portion is controlled so that the first absolute humidity becomes the target value, and the first absolute humidity is combined with the first absolute humidity. Since the voltage applied between the electrodes of the plasma processing unit is controlled so that the difference from the second absolute humidity falls within the range of the predetermined humidity difference, the humidity environment inside the honeycomb structure is kept constant and the gas It is possible to stabilize the processing capacity. Further, the problem that the humidity of the air after the plasma treatment becomes high and makes the person in the room feel uncomfortable does not occur.

Further, according to the present invention, the ability of the plasma processing unit is put into practical use before the control of the mixing ratio by the mixing ratio control unit and the control of the voltage applied between the electrodes of the plasma processing unit by the applied voltage control unit are started. Since the mixing ratio of the first gas and the second gas and the voltage applied between the electrodes of the plasma processing unit are controlled so as to maximize the processing capacity, before stabilizing the gas processing, The processing load in the plasma processing unit can be reliably obtained, and the processing capacity of the plasma processing unit can be quickly adjusted to an appropriate processing capacity corresponding to the processing load.

FIG. 1 is a diagram showing a main part of a gas treatment apparatus according to an embodiment of the present invention. FIG. 2 is a schematic view showing the configuration of a scrubber unit in this gas treatment apparatus. FIG. 3 is a schematic view showing the configuration of the plasma processing unit in this gas processing apparatus. FIG. 4 is a diagram showing an outline of the hardware configuration of the control device in this gas processing device. FIG. 5 is a flowchart for explaining a processing operation (processing operation performed by the mixing ratio applied voltage initial control unit) executed by the CPU of the control device. FIG. 6 is a flowchart for explaining a processing operation (processing operation performed by the mixing control unit) executed by the CPU of the control device. FIG. 7 is a flowchart for explaining a processing operation (processing operation performed by the applied voltage control unit) executed by the CPU of the control device. FIG. 8 is a flowchart for explaining a processing operation (processing operation performed by the mixing ratio applied voltage changing unit) executed by the CPU of the control device. FIG. 9 is a diagram showing the relationship between the mixing ratio M and the applied voltage V. FIG. 10 is a diagram showing a state in which the processing capacity of the plasma processing unit is adjusted to the point Z of the appropriate processing capacity corresponding to the processing load. FIG. 11A is a diagram showing a state (Δh> ΔhB + α) in which the difference Δh between the first absolute humidity hF and the second absolute humidity hR is large and is out of the reference humidity difference range ΔhB ± α. FIG. 11B is a diagram showing a state in which the difference Δh between the first absolute humidity hF and the second absolute humidity hR is within the reference humidity difference range ΔhB ± α. FIG. 12A is a diagram showing a state (Δh <ΔhB−α) in which the difference Δh between the first absolute humidity hF and the second absolute humidity hR is small and is out of the reference humidity difference range ΔhB ± α. FIG. 12B is a diagram showing a state in which the difference Δh between the first absolute humidity hF and the second absolute humidity hR falls within the reference humidity difference range ΔhB ± α. FIG. 13 shows the current operating point Z while maintaining the current processing capacity of the plasma processing unit with the specified practical upper limit mixing ratio Mmax and the changed applied voltage Vx (changed value in the direction of the practical lower limit voltage Vmin). It is a figure which shows the state which shifted to the point ZA defined by. FIG. 14 shows the current operating point Z while maintaining the current processing capacity of the plasma processing unit with the specified practical lower limit mixing ratio Mmin and the applied voltage Vx after the change (changed value in the direction of the practical upper limit voltage Vmax). It is a figure which shows the state which moved to the operation point ZB defined by. FIG. 15 shows the current operating point Z while maintaining the current processing capacity of the plasma processing unit with the specified practical lower limit voltage Vmin and the changed mixing ratio Vx (changed value in the direction of the practical upper limit mixing ratio Mmax). It is a figure which shows the state which shifted to the point ZC defined by. In FIG. 16, the current operating point Z is defined by the specified practical upper limit voltage Vmax and the mixing ratio Mx (change value in the direction of the practical lower limit mixing ratio Mmin) while maintaining the current processing capacity of the plasma processing unit. It is a figure which shows the state which moved to the point ZD which is done. FIG. 17 is a functional block diagram of a main part of the mixing control unit. FIG. 18 is a functional block diagram of a main part of the applied voltage control unit. FIG. 19 is a functional block diagram of a main part of the mixing ratio applied voltage changing portion. FIG. 20 is a diagram showing an example in which the gas to be processed before being humidified by the scrubber unit is supplied to the mixing unit as a second gas.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a main part of a gas treatment device 100 according to an embodiment of the present invention.

The gas treatment device 100 includes a scrubber unit (water treatment unit) 1, a mixing unit (mixing unit) 2, a plasma processing unit 3, and a flow rate of the processed gas E supplied to the mixing unit 2 arranged in the ventilation passage A. A control device 4 for controlling the voltage (hereinafter, also referred to as an applied voltage) V applied between the electrodes of the plasma processing unit 3 is provided.

In the gas treatment device 100, the duct A1 is connected to the ventilation passage A. The duct A1 is a duct extending from the downstream side of the plasma processing unit 3 to the mixing unit 2, and serves to return a part of the processed gas E to the mixing unit 2. The duct A1 is provided with an air supply valve 5 for adjusting the flow rate of the processed gas E returned to the mixing unit 2.

Further, in the gas processing device 100, the scrubber unit 1 humidifies the processing target gas B flowing through the ventilation passage A. The mixing unit 2 is provided on the downstream side of the ventilation passage A with respect to the scrubber unit 1, the processing target gas C humidified by the scrubber unit 1 is used as the first gas G1, and the processed gas E via the duct A1 is used as the second gas. The humidity is adjusted by mixing the first gas G1 and the second gas G2. The plasma processing unit 3 is provided on the downstream side of the ventilation passage A from the mixing unit 2, and the processing target gas whose humidity has been adjusted in the mixing unit 2 is input as the mixing processing target gas D, and the input mixing processing is performed. The target gas D is purified to be treated gas E.

Further, in the gas processing apparatus 100, in the ventilation path A between the mixing unit 2 and the plasma processing unit 3, the absolute humidity of the gas D to be mixed and processed from the mixing unit 2 to the plasma processing unit 3 is set to the first absolute humidity. A humidity sensor S1 that measures the humidity hF is provided. Further, in the ventilation passage A on the downstream side of the plasma processing unit 3, a humidity sensor S2 that measures the absolute humidity of the processed gas E that has passed through the plasma processing unit 3 as a second absolute humidity hR is provided.

The toxic gas contained in the gas B to be treated includes nitrogen oxides (NOx), sulfur oxides (SOx), chlorofluorocarbons, and carbon dioxide (CO ₂ ). , Volatile organic solvent (VOC), etc. Further, the dust contained in the gas B to be treated includes inorganic dust such as metal powder and rock powder, and organic dust such as cotton dust. In the present invention, soot dust generated by burning a substance and exhaust gas from an automobile or the like are used. Particulate matter contained in the gas shall also be included in the dust.

FIG. 2 is a schematic view showing the configuration of the scrubber unit 1 in the gas processing apparatus 100. As shown in FIG. 2, the inside of the tank 11 of the scrubber unit 1 is partitioned by two spaces 13-1 and 13-2 in a state where the lower part is communicated with each other by a partition plate 12. In one space 13-1, the filler 14 is supported by the inner wall 11a of the tank 11 and the partition plate 12, and the spraying portion 15 is sprayed above the filler 14 in a mist form toward the filler 14. Is provided.

Further, the tank 11 located above the spraying portion 15 is provided with an exhaust port 16 that exhausts the gas C to be processed having a relative humidity of 100% that has passed through the filler 14 to the air passage A. Further, the tank 11 forming the space 13-2 opposite to the space 13-1 in which the filler 14 is supported is provided with an intake port 17 which is connected to the ventilation passage A and takes in the gas B to be processed. ing. Further, the filler 14 is made of a resin such as polyester or polypropylene processed into a fibrous form, and voids are formed between the fibrous resins.

A water tank 18 for storing water is provided at the bottom of the tank 11, and a pump 19 for pumping the water of the water tank 18 to the spraying portion 15 is provided for the water tank 18. A drain hose 20 is connected to the bottom surface of the water tank 18, and the drain hose 20 is provided with a drain valve 21. Further, the tank 11 is provided with a water supply port 22, and a water supply hose 23 is connected to the water supply port 22.

The water stored in the water tank 18 is used as circulating water, is pumped by the pump 19, and is sprayed by the spraying unit 15 to repeat the cycle. When it becomes necessary to replace the circulating water due to dirt or the like, the drain valve 21 is opened to drain water from the drain hose 20, and new water is supplied from the water supply port 22 to which the water supply hose 23 is connected.

In the scrubber unit 1 configured in this way, the gas B to be processed sent into the tank 11 from the intake port 17 is in the form of mist sprayed from the spraying portion 15 when the gap in the filler 14 rises. Gas-liquid contact with water. In the present embodiment, the relative humidity of the inflowing treatment target gas B is set to 100% by bringing the treatment target gas B into gas-liquid contact with water. The gas C to be treated having a relative humidity of 100% is exhausted from the exhaust port 16 of the scrubber unit 1.

In the mixing unit 2, the treatment target gas C having a relative humidity of 100% taken in from the scrubber unit 1 side is used as the first gas G1, the treated gas E via the duct A1 is used as the second gas G2, and the first gas is used. By mixing G1 and the second gas G2, a humidity-adjusted gas D to be mixed is produced.

In the mixing unit 2, the treated gas E supplied as the second gas G2 has a lower humidity than the mixing processing target gas D. That is, when the water content of the gas D to be mixed is consumed by the plasma processing unit 3, the water concentration in the treated gas E is lower than the water concentration of the gas D to be mixed. The mixing unit 2 mixes the treated gas E having a humidity lower than that of the gas D to be mixed and the gas C to be treated having a relative humidity of 100%. In this case, the humidity of the gas D to be mixed is determined by the mixing ratio M (M = G1 / G2) of the first gas G1 and the second gas G2. The mixing ratio M is controlled by the mixing control unit 7 in the control device 4. The control of the mixing ratio M by the mixing control unit 7 will be described later.

FIG. 3 is a schematic view showing the configuration of the plasma processing unit 3 in the gas processing apparatus 100. As shown in FIG. 3, the plasma processing unit 3 includes a honeycomb structure 31 through which the gas D to be mixed is passed, a first electrode 32 arranged on the upstream side of the honeycomb structure 31, and a honeycomb structure 31. A second electrode 33 arranged on the downstream side of the honeycomb and a high voltage power supply 34 for applying a high voltage between the first electrode 32 and the second electrode 33 are provided.

The honeycomb structure 31 has a large number of through holes 31a formed in a honeycomb shape in the direction in which the gas D to be mixed and processed flowing through the ventilation passage A passes, and is made of ceramic or the like. The first electrode 32 is connected to the positive electrode of the high voltage power supply 34 via a conducting wire, and is made of a metal mesh or the like. The second electrode 33 is connected to the negative electrode of the high voltage power supply 34 via a conducting wire, and is made of a metal mesh or the like. The mesh shapes of the first electrode 32 and the second electrode 33 are coarser than the through holes 31a formed in the honeycomb structure 31. The high voltage power supply 34 applies a high voltage of several kV to several tens of kV as the voltage V between the first electrode 32 and the second electrode 33.

When a high voltage is applied between the first electrode 32 and the second electrode 33 in the plasma processing unit 3, plasma is generated inside the through hole 31a of the honeycomb structure 31. As a result, the harmful gas contained in the gas D to be mixed is decomposed into a harmless substance by the ions and radicals generated in the plasma. Further, the dust contained in the gas D to be mixed is charged and adhered to the first electrode 32 and the second electrode 33, and is adsorbed and removed. The gas processed by the plasma processing unit 3 is exhausted as the processed gas E to the downstream side of the ventilation passage A.

In the gas processing device 100, the control device 4 includes a mixing ratio applied voltage initial control unit 6, a mixing control unit 7, an applied voltage control unit 8, and a mixing ratio applied voltage changing unit 9. Further, the control device 4 is provided with a mixing ratio applied voltage change value designation unit 10. FIG. 4 shows an outline of the hardware configuration of the control device 4.

The control device 4 includes a central processing unit (CPU) 4-1 and a random access memory (RAM) 4-2, a read-only memory (ROM) 4-3, interfaces 4-4, 4-5, and the like. It is equipped with a bus 4-6 to connect to. Further, a mixing ratio applied voltage control program is installed in the control device 4 as a program peculiar to the present embodiment.

The CPU 4-1 operates according to the mixing ratio applied voltage control program installed in the control device 4 while accessing the RAM 4-2 and the ROM 4-3 by processing the information input via the interface 4-4. To do. In the control device 4, the mixing ratio applied voltage initial control unit 6, the mixing control unit 7, the applied voltage control unit 8, and the mixing ratio applied voltage changing unit 9 are realized as processing functions of the CPU 4-1.

Hereinafter, the processing operation of the CPU 4-1 according to this mixing ratio applied voltage control program will be described with reference to the flowcharts shown in FIGS. 5 to 8. Here, the mixing ratio applied voltage initial control unit 6 performs the processing operation according to the flowchart shown in FIG. 5, the mixing control unit 7 performs the processing operation according to the flowchart shown in FIG. 6, and the applied voltage control unit 8 shows the processing operation according to the flowchart. The processing operation according to the flowchart shown will be described as assuming that the mixing ratio applied voltage changing unit 9 performs the processing operation according to the flowchart shown in FIG.

[Initial control of mixing ratio and applied voltage]
When the gas processing device 100 is started, the mixing ratio applied voltage initial control unit 6 controls the mixing ratio M by the mixing control unit 7, which will be described later, and the voltage V applied between the electrodes of the plasma processing unit 3 by the applied voltage control unit 8. Mixing ratio M of the first gas G1 and the second gas G2 in the mixing unit 2 and the plasma processing so that the gas processing capacity of the plasma processing unit 3 becomes the maximum practical processing capacity before the control of the above is started. The voltage V applied between the electrodes of the unit 3 is controlled (FIG. 5: steps S101 and S102).

FIG. 9 shows the relationship between the mixing ratio M and the applied voltage V. In the figure, the vertical axis represents the applied voltage V and the horizontal axis represents the mixing ratio M. In the present embodiment, the mixing ratio M is expressed as M = G1 / G2, and the larger the mixing ratio M, the higher the water concentration in the mixing treatment target gas D, and the smaller the mixing ratio M, the higher the mixing treatment target gas D. The water concentration of the gas becomes low. That is, the larger the mixing ratio M, the higher the humidity of the mixing treatment target gas D, and the smaller the mixing ratio M, the lower the humidity of the mixing treatment target gas D.

The gas processing capacity of the plasma processing unit 3 is determined by the product of the magnitude of the applied voltage V and the mixing ratio M. However, a controllable range is defined for both the applied voltage V and the mixing ratio M. That is, the upper limit value of the applied voltage V at which spark discharge (abnormal discharge) does not occur in the plasma processing unit 3 is set as the practical upper limit voltage Vmax, and the lower limit value of the applied voltage capable of generating plasma in the plasma processing unit 3 is set. When the practical lower limit voltage Vmin is set, the controllable range of the applied voltage V is defined as Vmin ≦ V ≦ Vmax. Further, the mixing ratio M corresponding to the allowable upper limit value of the first absolute humidity hF (the limit value of humidity that does not impair the comfort of the room) is set as the practical upper limit mixing ratio Mmax, and the plasma generated by the lack of water in the plasma processing unit 3 is set. When the mixing ratio M corresponding to the lower limit of the first absolute humidity hF in which no by-product is generated from the gas D to be mixed is set to the practical lower limit mixing ratio Mmin, the controllable range of the mixing ratio M is Mmin. It is defined as ≦ M ≦ Mmax.

Therefore, the practical gas processing capacity of the plasma processing unit 3 is minimized at the point X (Mmin, Vmin) where the applied voltage V is the practical lower limit voltage Vmin and the mixing ratio M is the practical lower limit mixing ratio Mmin, and the applied voltage V Is the practical upper limit voltage Vmax, and the point Y (Mmax, Vmax) where the mixing ratio M is the practical upper limit mixing ratio Mmax is the maximum.

When the gas processing device 100 is started, the mixing ratio applied voltage initial control unit 6 adjusts the opening degree θ of the air supply valve 5 so that the mixing ratio M in the mixing unit 2 is the practical upper limit mixing ratio Mmax (step S101). .. Further, the voltage V between the electrodes of the plasma processing unit 3 is set to the practical upper limit voltage Vmax (step S102). As a result, the gas processing capacity of the plasma processing unit 3 is set to the practical maximum processing capacity (Mmax, Vmax) before the mixing control unit 7 and the applied voltage control unit 8 start the control operation described later.

[Control of mixing ratio]
When the mixing control unit 7 receives a notification from the applied voltage control unit 8 that the calculation of the processing load in the plasma processing unit 3 described later has been completed (YES in step S201), the first absolute measured by the humidity sensor S1. Humidity hF is taken in (step S202), a preset target value hsp is read out (step S203), and the first absolute humidity hF taken in is compared with the read out target value hsp (step S204).

Here, if the first absolute humidity hF does not match the target value hsp (NO in step S204), the mixing control unit 7 supplies air so that the first absolute humidity hF and the target value hsp match. The opening degree θ of the valve 5 is adjusted (step S205). That is, the mixing control unit 7 adjusts the flow rate of the processed gas E supplied to the mixing unit 2 so that the first absolute humidity hF and the target value hsp match with each other. The mixing ratio M of the gas G1 and the second gas G2 is adjusted (controlled).

In this embodiment, the mixing ratio M of the first gas G1 and the second gas G2 is adjusted so that the relative humidity of the gas D to be mixed is about 90% by setting the target value hsp. As a result, the gas D to be mixed and treated having a relative humidity of about 90% is sent to the plasma processing unit 3.

Here, about 90% set as the relative humidity of the gas D to be mixed is a water content sufficient for generating plasma discharge and a water content for suppressing the occurrence of abnormal discharge such as spark discharge. In this example, the relative humidity of the gas D to be mixed is set to about 90%, but this is only an example. If the amount of water is sufficient to generate plasma discharge and the amount of water suppresses abnormal discharge such as spark discharge, the relative humidity of the gas D to be mixed is set, that is, the first absolute humidity hF. The target value hsp to be determined can be changed as appropriate.

[Control of applied voltage]
When the gas processing capacity of the plasma processing unit 3 is set to the practical maximum processing capacity by the mixing ratio applied voltage initial control unit 6 (YES in FIG. 7: step S301), the humidity sensor S1 measures the applied voltage control unit 8. The absolute humidity hF of 1 and the second absolute humidity hR measured by the humidity sensor S2 are captured (step S302), and the difference between the captured first absolute humidity hF and the second absolute humidity hR Δh (Δh = hF−). hR) is calculated (step S303). Then, the applied voltage control unit 8 obtains the processing load in the plasma processing unit 3 from the difference Δh between the first absolute humidity hF and the second absolute humidity hR (step S304).

In the processing operation shown in FIG. 6, the mixing control unit 7 waits for the calculation of the processing load by the applied voltage control unit 8 (FIG. 6: YES in step S201), and then the first absolute humidity hF and the target value hsp. The mixing ratio M of the first gas G1 and the second gas G2 is adjusted (controlled) so as to match the above, that is, so that the relative humidity of the gas D to be mixed is about 90%.

The applied voltage control unit 8 has a processing capacity corresponding to the processing load calculated in step S304 in a state where the mixing ratio M is adjusted so that the first absolute humidity hF and the target value hsp match. The voltage V applied between the electrodes of the plasma processing unit 3 is adjusted (step S305). As a result, the gas processing capacity of the plasma processing unit 3, which has been regarded as the maximum practical processing capacity, is narrowed down and approaches an appropriate gas processing capacity corresponding to the processing load.

The applied voltage control unit 8 sets the first absolute humidity hF measured by the humidity sensor S1 and the second absolute humidity hR measured by the humidity sensor S2 in a state of approaching an appropriate gas processing capacity corresponding to this processing load. Taking in (step S306), the difference Δh (Δh = hF-hR) between the taken-in first absolute humidity hF and the second absolute humidity hR is calculated (step S307).

Then, the applied voltage control unit 8 reads out a reference humidity difference range ΔhB ± α preset as a predetermined temperature difference range (step S308), and sets the first absolute humidity hF and the second absolute humidity hR. The voltage V applied between the electrodes of the plasma processing unit 3 is adjusted (controlled) so that the difference Δh falls within the reference humidity difference range ΔhB ± α (steps S309 to S312).

That is, as shown in FIG. 11A, when the difference Δh between the first absolute humidity hF and the second absolute humidity hR is large and is out of the reference humidity difference range ΔhB ± α (Δh> ΔhB + α, YES in step S309). ), The applied voltage control unit 8 lowers the voltage V applied between the electrodes of the plasma processing unit 3 (step S310).

As a result, the gas processing capacity of the plasma processing unit 3 for the gas D to be mixed is suppressed, the amount of water consumed by the plasma processing unit 3 is reduced, the second absolute humidity hR is increased, and the first absolute humidity hF is increased. The difference Δh between the first absolute humidity hR and the second absolute humidity hR becomes smaller, and the difference Δh between the first absolute humidity hF and the second absolute humidity hR falls within the reference humidity difference range ΔhB ± α (see FIG. 11B). ).

Further, as shown in FIG. 12A, when the difference Δh between the first absolute humidity hF and the second absolute humidity hR is small and is out of the reference humidity difference range ΔhB ± α (Δh <ΔhB−α, step S311). YES), the applied voltage control unit 8 raises the voltage V applied between the electrodes of the plasma processing unit 3 (step S312).

As a result, the gas processing capacity of the plasma processing unit 3 for the gas D to be mixed is increased, the amount of water consumed by the plasma processing unit 3 is increased, the second absolute humidity hR is lowered, and the first absolute humidity hF is increased. The difference Δh from the second absolute humidity hR becomes large, and the difference Δh between the first absolute humidity hF and the second absolute humidity hR falls within the reference humidity difference range ΔhB ± α (see FIG. 12B). ..

In this way, in the present embodiment, the mixing ratio M of the first gas G1 and the second gas G2 is adjusted (controlled) so that the first absolute humidity hF has the target value hsp, and the first The voltage V applied between the electrodes of the plasma processing unit 3 is adjusted (controlled) so that the difference Δh between the absolute humidity hF and the second absolute humidity hR falls within the reference humidity difference range ΔhB ± α.

FIG. 10 shows a state in which the processing capacity of the plasma processing unit 3 is adjusted to the point Z (MR, VR) of the appropriate processing capacity corresponding to the processing load. MR is the adjusted mixing ratio M, and VR is the adjusted applied voltage V. Hereinafter, this point Z is also referred to as an operation point.

As a result, in the present embodiment, the humidity environment in the honeycomb structure 31 is kept constant, and the gas processing capacity is stabilized. Further, when the air after the plasma treatment is supplied to the room, the humidity of the air after the plasma treatment becomes high and the person in the room does not feel uncomfortable.

Further, in the present embodiment, the processing capacity of the plasma processing unit 3 is first set as the practical maximum processing capacity (Mmax, Vmax), and the processing load of the plasma processing unit 3 is obtained so that the processing capacity corresponds to this processing load. Since the voltage V applied between the electrodes of the plasma processing unit 3 is adjusted, the processing capacity of the plasma processing unit 3 can be quickly reached the point Z (MR, VR) of the appropriate processing capacity corresponding to the processing load. Can be combined. Further, since the processing capacity of the plasma processing unit 3 is initially set to the practical maximum processing capacity (Mmax, Vmax), there is no possibility that the processing capacity of the plasma processing unit 3 cannot be obtained due to insufficient capacity. As a result, the processing load of the plasma processing unit 3 can be reliably obtained before the gas processing capacity is stabilized.

[Change of mixing ratio and applied voltage]
[Example 1]
The mixing ratio applied voltage changing unit 9 specifies the mixing ratio applied voltage change value in a state where the processing capacity of the plasma processing unit 3 is adjusted to the point Z (MR, VR) of the appropriate processing capacity corresponding to the processing load. When, for example, the practical upper limit mixing ratio Mmax is specified as the changed value (value after change) of the mixing ratio M from the unit 10 (FIG. 8: YES in step S401), the current processing capacity exhibited by the plasma processing unit 3 is exhibited. The applied voltage Vx capable of maintaining the above is obtained as a changed value (changed value) of the applied voltage V (step S402).

In this case, since the mixing ratio applied voltage changing unit 9 is required to maintain the current processing capacity exhibited by the plasma processing unit 3, the applied voltage Vx is used as a change value in the direction of the practical lower limit voltage Vmin. Ask for.

Then, the mixing ratio applied voltage changing unit 9 sends the practical upper limit mixing ratio Mmax designated as the changing value of the mixing ratio M by the mixing ratio applied voltage changing value specifying unit 10 to the mixing control unit 7, and the mixing control unit 7 controls. The mixing ratio M to be used is changed to the practical upper limit mixing ratio Mmax (step S403). Further, the applied voltage Vx obtained as a change value of the applied voltage V is sent to the applied voltage control unit 8 to change the voltage V applied between the electrodes of the plasma processing unit 3 to Vx (step S403).

In FIG. 13, the current operating point Z (MR, VR) is set to the practical upper limit mixing ratio Mmax (specified change value) and the applied voltage Vx (practical lower limit voltage Vmin) while maintaining the current processing capacity of the plasma processing unit 3. The state of shifting to the operation point ZA (Mmax, Vmin) defined by (the calculated change value in the direction of) is shown. As can be seen from this figure, in Example 1, the voltage V applied between the electrodes of the plasma processing unit 3 is lowered, and energy saving control is realized while emphasizing the gas processing capacity.

[Example 2]
The mixing ratio applied voltage changing unit 9 specifies the mixing ratio applied voltage change value in a state where the processing capacity of the plasma processing unit 3 is adjusted to the point Z (MR, VR) of the appropriate processing capacity corresponding to the processing load. When, for example, the practical lower limit mixing ratio Mmin is specified as the changed value (value after change) of the mixing ratio M from the unit 10 (FIG. 8: YES in step SS401), the current processing capacity exhibited by the plasma processing unit 3 is exhibited. The applied voltage Vx capable of maintaining the above is obtained as a changed value (changed value) of the applied voltage V (step S402).

In this case, since the mixing ratio applied voltage changing unit 9 is required to maintain the current processing capacity exhibited by the plasma processing unit 3, the applied voltage Vx is used as a change value in the direction of the practical upper limit voltage Vmax. Ask for.

Then, the mixing ratio applied voltage changing unit 9 sends the practical lower limit mixing ratio Mmin designated as the changing value of the mixing ratio M by the mixing ratio applied voltage changing value specifying unit 10 to the mixing control unit 7, and the mixing control unit 7 controls it. The mixing ratio M to be used is changed to the practical lower limit mixing ratio Mmin (step S403). Further, the applied voltage Vx obtained as a change value of the applied voltage V is sent to the applied voltage control unit 8 to change the voltage V applied between the electrodes of the plasma processing unit 3 to Vx (step S403).

In FIG. 14, the current operating point Z (MR, VR) is set to the practical lower limit mixing ratio Mmin (specified change value) and the applied voltage Vx (practical upper limit voltage Vmax) while maintaining the current processing capacity of the plasma processing unit 3. The state of shifting to the operation point ZB (Mmin, Vx) defined by (the calculated change value in the direction of) is shown. As can be seen from this figure, in Example 2, the mixing ratio M controlled by the mixing control unit 7 is lowered (the humidity of the gas D to be mixed is lowered), and the humidity lowering control is performed while emphasizing the gas processing capacity. It will be realized.

[Example 3]
The mixing ratio applied voltage changing unit 9 specifies the mixing ratio applied voltage change value in a state where the processing capacity of the plasma processing unit 3 is adjusted to the point Z (MR, VR) of the appropriate processing capacity corresponding to the processing load. When, for example, the practical lower limit voltage Vmin is specified as the changed value (value after change) of the applied voltage V from the unit 10 (FIG. 8: YES in step S404), the current processing capacity exhibited by the plasma processing unit 3 is displayed. The mixing ratio Mx that can be maintained is obtained as a changed value (changed value) of the mixing ratio M (step S405).

In this case, since the mixing ratio applied voltage changing unit 9 is required to maintain the current processing capacity exhibited by the plasma processing unit 3, the mixing ratio is changed in the direction of the practical upper limit mixing ratio Mmax. Find Mx.

Then, the mixing ratio applied voltage changing unit 9 sends the practical lower limit voltage Vmin designated as the changing value of the applied voltage V by the mixing ratio applied voltage changing value specifying unit 10 to the applied voltage control unit 8, and the electrode of the plasma processing unit 3 The voltage V applied between them is changed to the practical lower limit voltage Vmin (step S406). Further, the mixing ratio Mx obtained as the change value of the mixing ratio M is sent to the mixing control unit 7, and the mixing ratio M controlled by the mixing control unit 7 is changed to Mx (step S406).

In FIG. 15, the current operating point Z (MR, VR) is set to the practical lower limit voltage Vmin (specified change value) and the mixing ratio Vx (practical upper limit mixing ratio Mmax) while maintaining the current processing capacity of the plasma processing unit 3. The state of shifting to the operation point ZC (Mx, Vmin) defined by (the calculated change value in the direction of) is shown. As can be seen from this figure, in Example 3, the voltage V applied between the electrodes of the plasma processing unit 3 is lowered, and energy saving control is realized while emphasizing the gas processing capacity.

[Example 4]
The mixing ratio applied voltage changing unit 9 specifies the mixing ratio applied voltage change value in a state where the processing capacity of the plasma processing unit 3 is adjusted to the point Z (MR, VR) of the appropriate processing capacity corresponding to the processing load. When, for example, the practical upper limit voltage Vmax is specified as the changed value (value after the change) of the applied voltage V from the unit 10 (FIG. 8: YES in step S404), the current processing capacity exhibited by the plasma processing unit 3 is displayed. The mixing ratio Mx that can be maintained is obtained as a changed value (changed value) of the mixing ratio M (step S405).

In this case, since the mixing ratio applied voltage changing unit 9 is required to maintain the current processing capacity exhibited by the plasma processing unit 3, the mixing ratio is changed in the direction of the practical lower limit mixing ratio Mmin. Find Mx.

Then, the mixing ratio applied voltage changing unit 9 sends the practical upper limit voltage Vmax designated as the changing value of the applied voltage V by the mixing ratio applied voltage changing value specifying unit 10 to the applied voltage control unit 8, and the electrode of the plasma processing unit 3 The voltage V applied between them is changed to the practical upper limit voltage Vmax (step S406). Further, the mixing ratio Mx obtained as the change value of the mixing ratio M is sent to the mixing control unit 7, and the mixing ratio M controlled by the mixing control unit 7 is changed to Mx (step S406).

In FIG. 16, the current operating point Z (MR, VR) is set to the practical upper limit voltage Vmax (specified change value) and the mixing ratio Mx (practical lower limit mixing ratio Mmin) while maintaining the current processing capacity of the plasma processing unit 3. The state of shifting to the operation point ZD (Mx, Vmax) defined by (the calculated change value in the direction of) is shown. As can be seen from this figure, in Example 4, the mixing ratio M controlled by the mixing control unit 7 is lowered (the humidity of the gas D to be mixed is lowered), and the humidity lowering control is performed while emphasizing the gas processing capacity. It will be realized.

In Examples 1 and 2 described above, the case where the practical upper limit mixing ratio Mmax and the practical lower limit mixing ratio Mmin are specified as the changed values of the mixing ratio M by the mixing ratio applied voltage change value specifying unit 10 has been described. In Examples 3 and 4, the case where the practical lower limit voltage Vmin and the practical upper limit voltage Vmax are specified as the change values of the applied voltage V from the mixing ratio applied voltage change value specifying unit 10 has been described. The change value of the mixing ratio M and the change value of the applied voltage V specified from 10 are not limited to these. For example, a change value of the mixing ratio M may be specified as an arbitrary value in the range from the practical upper limit mixing ratio Mmax to the practical lower limit mixing ratio Mmin by an operation such as a dial, from the practical lower limit voltage Vmin to the practical upper limit voltage Vmax. The change value of the applied voltage V may be specified as an arbitrary value in the range of.

FIG. 17 shows a functional block diagram of a main part of the mixing control unit 7. The mixing control unit 7 includes a first absolute humidity intake unit 71, a target value storage unit 72, a humidity comparison unit 73, and an opening degree adjusting unit (mixing ratio adjusting unit) 74.

In the mixing control unit 7, the first absolute humidity intake unit 71 captures the first absolute humidity hF measured by the humidity sensor S1. The target value storage unit 72 stores a preset target value hsp. The humidity comparison unit 73 compares the first absolute humidity hF taken in by the first absolute humidity acquisition unit 71 with the target value hsp stored in the target value storage unit 72. Based on the comparison result from the humidity comparison unit 73, the opening degree adjusting unit (mixing ratio adjusting unit) 74 increases the opening degree θ of the air supply valve 5 so that the first absolute humidity hF and the target value hsp match. (Mixing ratio M in the mixing unit 2) is adjusted.

FIG. 18 shows a functional block diagram of a main part of the applied voltage control unit 8. The applied voltage control unit 8 includes a first absolute humidity intake unit 81, a second absolute humidity intake unit 82, a humidity difference calculation unit 83, a reference humidity difference range storage unit 84, and an applied voltage adjustment unit 85. And have.

In the applied voltage control unit 8, the first absolute humidity intake unit 81 captures the first absolute humidity hF measured by the humidity sensor S1, and the second absolute humidity intake unit 82 is measured by the humidity sensor S2. The second absolute humidity hR is taken in. The humidity difference calculation unit 83 calculates the difference Δh (Δh = hF−hR) between the first absolute humidity hF measured by the humidity sensor S1 and the second absolute humidity hR measured by the humidity sensor S2. The reference humidity difference range storage unit 84 stores a preset reference humidity difference range ΔhB ± α.

The applied voltage adjusting unit 85 confirms whether or not the humidity difference Δh calculated by the humidity difference calculating unit 83 is within the reference humidity difference range ΔhB ± α, and the calculated humidity difference Δh is the reference humidity difference range. When the calculated humidity difference Δh is smaller than the reference humidity difference range ΔhB−α, the voltage V applied between the electrodes of the plasma processing unit 3 is lowered when it is larger than ΔhB + α. The voltage V applied between the electrodes of the plasma processing unit 3 is adjusted so as to increase the voltage V applied between the electrodes of.

FIG. 19 shows a functional block diagram of a main part of the mixing ratio applied voltage changing unit 9. The mixture ratio applied voltage changing unit 9 includes a designated change value acquisition unit 91, an applied voltage change value calculation unit 92, a mixture ratio change value calculation unit 93, and a change value output unit 94.

In the mixture ratio applied voltage change unit 9, the designated change value acquisition unit 91 acquires the change value designated by the mixture ratio applied voltage change value designation unit 10. In the applied voltage change value calculation unit 92, when the change value acquired by the designated change value acquisition unit 91 is the change value of the mixing ratio M, the difference Δh between the first absolute humidity hF and the second absolute humidity hR is Under the condition of the reference humidity difference range ΔhB ± α, the change value Vx of the voltage V applied to the plasma processing unit 3 is calculated on condition that the current processing capacity exhibited by the plasma processing unit 3 is exhibited. ..

In the mixing ratio change value calculation unit 93, when the change value acquired by the designated change value acquisition unit 91 is the change value of the applied voltage V, the difference Δh between the first absolute humidity hF and the second absolute humidity hR is Under the condition of the reference humidity difference range ΔhB ± α, the change value Mx of the mixing ratio M to the mixing control unit 7 is calculated on condition that the current processing capacity exhibited by the plasma processing unit 3 is exhibited. ..

The change value output unit 94 sends the change value Vx of the applied voltage V calculated by the applied voltage change value calculation unit 92 to the applied voltage control unit 8, and changes the mixing ratio M calculated by the mixture ratio change value calculation unit 93. The value Mx is sent to the mixing control unit 7.

In the above-described embodiment, the applied voltage control unit 8 adjusts (controls) the value (level) of the voltage V applied between the electrodes of the plasma processing unit 3, but the electrodes of the plasma processing unit 3 It is assumed that the voltage V is applied periodically between them, and the duty ratio (ratio of the on time and the off time in one cycle) of the applied voltage V may be adjusted (controlled).

Further, in the above-described embodiment, the scrubber unit 1 adjusts the relative humidity of the gas B to be treated to 100%, but the relative humidity adjusted by the scrubber unit 1 is not limited to 100%. That is, if a stable high humidity processing target gas B can be obtained, the set value of the relative humidity adjusted by the scrubber unit 1 can be appropriately set.

Further, in the above-described embodiment, the duct A1 extending from the downstream side of the plasma processing unit 3 to the mixing unit 2 is provided, and the processed gas E is supplied to the mixing unit 2 as the second gas G2. As shown in FIG. 20, a duct A2 extending from the upstream side of the scrubber unit 1 to the mixing unit 2 is provided so that the gas B to be processed before being humidified by the scrubber unit 1 is supplied to the mixing unit 2 as a second gas G2. It may be.

Further, in the above-described embodiment, by providing the mixing ratio applied voltage changing unit 9, energy saving control can be performed while emphasizing the gas processing capacity, or humidity reduction control can be performed while emphasizing the gas processing capacity. Although this has been done, the present invention may be applied to a gas treatment device of a type that does not provide the mixing ratio applied voltage changing unit 9.

[Extension of Embodiment]
Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the structure and details of the present invention within the scope of the technical idea of the present invention.

The gas treatment apparatus of the present invention can also be applied to so-called reforming in which hydrogen-containing gas is generated from hydrocarbons or the like for the purpose of efficiently generating hydrogen used in a fuel cell or the like.
For example, in the case of octane (a substance relatively close to the average molecular weight of gasoline) C ₈ H ₁₈ , when it is supplied to this gas treatment device, the chemical reaction represented by the following equation (1) is promoted, and as a result, hydrogen gas is efficiently generated. can do.
_{C 8 H 18 + 8H 2 O} + 4 (O 2 + 4N 2) → 8CO 2 + 17H 2 + 16N 2 ···· (1)

1 ... Scrubber unit (water treatment unit), 2 ... Mixing unit (mixing unit), 3 ... Plasma processing unit, 4 ... Control device, 4-1 ... CPU, 4-2 ... RAM, 4-3 ... ROM, 4- 4,4-5 ... Interface, 5 ... Air supply valve, 6 ... Mixing ratio applied voltage initial control unit, 7 ... Mixing control unit, 8 ... Applied voltage control unit, 9 ... Mixing ratio applied voltage changing unit, A ... Ventilation path , A1, A2 ... duct, S1, S2 ... humidity sensor, 31 ... honeycomb structure, 32, 33 ... electrodes, 71 ... first absolute humidity intake unit, 72 ... target value storage unit, 73 ... humidity comparison unit, 74 ... Opening adjustment unit (mixing ratio adjustment unit), 81 ... First absolute humidity intake unit, 82 ... Second absolute humidity intake unit, 83 ... Humidity difference calculation unit, 84 ... Reference humidity difference range storage unit , 85 ... applied voltage adjusting unit, 91 ... specified change value acquisition unit, 92 ... applied voltage change value calculation unit, 93 ... mixture ratio change value calculation unit, 94 ... change value output unit, 100 ... gas processing device.

Claims (3)

In a gas treatment device configured to purify the gas to be treated and output it as treated gas.
A water treatment unit arranged in a ventilation passage and configured to humidify the gas to be treated flowing through the ventilation passage.
The gas to be treated, which is provided on the downstream side of the ventilation passage from the water treatment section and is humidified by the water treatment section, is used as the first gas, and the gas to be treated or the treatment before being humidified by the water treatment section. A mixing unit configured to use the finished gas as a second gas and to adjust the humidity by mixing the first gas and the second gas.
A honeycomb structure provided on the downstream side of the ventilation passage with respect to the mixing portion and having a large number of through holes through which the treatment target gas whose humidity is adjusted in the mixing portion passes as the mixing treatment target gas, and the mixing. It has electrodes arranged on the upstream side and the downstream side of the honeycomb structure with respect to the direction in which the gas to be processed passes, and plasma is applied to the through holes of the honeycomb structure by the voltage applied between the electrodes. A plasma processing unit configured to generate,
A first humidity measuring unit configured to measure the absolute humidity of the gas to be mixed and processed from the mixing unit to the plasma processing unit as the first absolute humidity.
A second humidity measuring unit configured to use the gas to be mixed and processed that has passed through the plasma processing unit as the processed gas and measure the absolute humidity of the processed gas as the second absolute humidity.
A mixing ratio control unit configured to control the mixing ratio of the first gas and the second gas in the mixing unit so that the first absolute humidity becomes a target value.
Applied voltage control configured to control the voltage applied between the electrodes of the plasma processing unit so that the difference between the first absolute humidity and the second absolute humidity falls within a predetermined humidity difference range. Department and
Before the control of the mixing ratio by the mixing ratio control unit and the control of the voltage applied between the electrodes of the plasma processing unit by the applied voltage control unit are started, the capacity of the plasma processing unit is the maximum practical processing capacity. The mixing ratio applied voltage initial control unit configured to control the mixing ratio of the first gas and the second gas and the voltage applied between the electrodes of the plasma processing unit so as to be. A gas treatment device characterized by being provided. In the gas treatment apparatus according to claim 1,
The mixing ratio applied voltage initial control unit
The mixing ratio determined based on the allowable upper limit value set for the first absolute humidity is set as the practical upper limit mixing ratio, and is determined based on the upper limit value of the applied voltage at which spark discharge does not occur in the plasma processing unit. The first gas is set to the practical upper limit voltage, the mixing ratio is the practical upper limit mixing ratio, and the voltage applied between the electrodes of the plasma processing unit is the practical upper limit voltage. A gas processing apparatus characterized in that it is configured to control the mixing ratio of the second gas and the voltage applied between the electrodes of the plasma processing unit. In the gas treatment apparatus according to claim 1,
Under the circumstance that the difference between the first absolute humidity measured by the first humidity measuring unit and the second absolute humidity measured by the second humidity measuring unit is within the predetermined humidity difference range. In the above, the mixing ratio controlled by the mixing ratio control unit is changed within the range from the practical upper limit mixing ratio to the practical lower limit mixing ratio on condition that the current processing capacity exhibited by the plasma processing unit is maintained. Further, the gas is further provided with a mixing ratio applied voltage changing unit configured to change the voltage applied between the electrodes of the plasma processing unit within the range from the practical upper limit voltage to the practical lower limit voltage. Processing equipment.