JP5597008B2 - Gas processing equipment - Google Patents

Description

  The present invention relates to a gas processing apparatus that purifies harmful gas contained in a gas to be processed.

  2. Description of the Related Art Conventionally, a technique for purifying harmful gas contained in exhaust gas by creating a plasma state by performing high voltage discharge in the exhaust gas is known. In recent years, this technology is being applied to a purification device for purifying factory exhaust and an air purifier for purifying indoor air for the purpose of deodorization.

  Plasma that is in a thermally non-equilibrium state, that is, in which the electron temperature is much higher than the temperature of the gas or ion (non-equilibrium plasma (hereinafter simply referred to as plasma)) is the ion or radical produced by electron collision. Promotes a chemical reaction that does not occur at room temperature, and is considered useful in hazardous gas treatment as a medium that can efficiently remove or decompose harmful gases. The key to practical use is to improve the energy efficiency during processing and to convert it into a completely safe product after processing with plasma.

In general, plasma at atmospheric pressure is generated by gas discharge or electron beam. There are nitrogen oxides (NOx), sulfur oxides (SOx), chlorofluorocarbons, CO ₂ , volatile organic solvents (VOC), etc. that are currently being considered for application. Above all, NOx is contained in the exhaust gas of a car, so that it needs to be put into practical use immediately.

The phenomenon in discharge plasma (plasma generated by gas discharge) in NOx removal is that ions and radicals generated primarily by electron collision cause an initial reaction, and N ₂ , H ₂ O, It is thought that it is converted into each particle such as NH ₄ NO ₃ .

Further, when the harmful gas is, for example, acetaldehyde or formaldehyde, the harmful gas is converted into CO ₂ and H ₂ O by passing plasma. In this case, ozone (O ₃ ) is generated as a by-product.

  FIG. 6 illustrates a main part of a conventional gas processing apparatus using discharge plasma (for example, see Patent Document 1). In the figure, reference numeral 1 denotes a duct (ventilation path) through which a gas to be treated (air containing toxic gas) GS flows. Inside the duct 1 is a discharge electrode 2 and a ground along the direction from the inlet to the outlet of the duct 1. The electrodes 3 are alternately arranged, and a honeycomb structure 4 having a large number of through holes 4 a called cells is disposed between the electrodes 2 and 3. The through holes 4a are provided in the honeycomb structure 4 in a honeycomb shape. Reference numeral 5 denotes a high voltage power source. The honeycomb structure 4 is formed of an insulator such as ceramics, and Patent Document 2 also has an example of its use.

  The discharge electrode 2 is formed of a metal mesh, a fine wire, a needle-like body, or the like. Each discharge electrode 2 is connected to the + pole of the high voltage power supply 5 by a conducting wire 6. The ground electrode 3 is formed of a metallic mesh or the like. Each ground electrode 3 is connected to the negative pole of the high voltage power supply 5 by a conducting wire 7.

  In this gas processing apparatus, the gas GS to be processed is caused to flow through the duct 1, and a high voltage (several kV to several tens kV) from the high voltage power supply 5 is applied between the discharge electrode 2 and the ground electrode 3. Thereby, plasma is generated in the through-holes 4a of the honeycomb structures 4, and harmful gases contained in the processing target gas GS are decomposed into harmless substances by ions and radicals generated in the plasma.

However, the gas processing apparatus having such a configuration has the following problems.
(1) Although a large number of honeycomb structures 4 are provided, a technique for generating uniform plasma without variations has not been established, and variations in the performance of the honeycomb structures 4 occur. For example, impedance values may be different even in the same honeycomb structure 4, and impedance values may be different in one honeycomb structure 4, for example, at the top and bottom thereof, so that uniform plasma can be generated as a whole. Therefore, the gas processing capacity becomes unstable. Further, since plasma is generated only through the through holes 4a, the amount of plasma generated is small and the gas processing capacity is low.

(2) The honeycomb structure 4 has a characteristic of low impedance when moisture is absorbed and high impedance when dried. When the honeycomb structure 4 becomes low impedance, the flowing current increases and the discharge electrode 2 and the ground electrode 3 When the high voltage value applied between them decreases and the honeycomb structure 4 becomes high impedance, the flowing current decreases and the high voltage value applied between the discharge electrode 2 and the ground electrode 3 increases. The high voltage power supply 5 that can obtain a high voltage value that can secure a desired plasma generation amount with respect to such a change in the high voltage value is very expensive including the man-hours required for its design.
(3) Since the discharge electrode 2 and the ground electrode 3 are provided for each of the honeycomb structures 4, the number of parts is large, the structure is complicated, and the cost is high.

  Therefore, the present applicant has proposed a gas processing apparatus having a structure as shown in FIG. 7 as a solution to the problems of the conventional gas processing apparatus described above (see Patent Document 3). In this gas processing apparatus, a plurality of honeycomb structures 4 having a large number of through holes (round holes) 4a are arranged at intervals along the direction of passage of the processing target gas GS from the inlet to the outlet of the duct 1. Yes. In this example, a gap G1 is provided between the honeycomb structures 4-1 and 4-2, and a gap G2 is provided between the honeycomb structures 4-3 and 4-4. ˜4-4 are arranged in the duct 1.

  The honeycomb structures 4-1 and 4-2 constitute a first honeycomb structure group 4A, and the honeycomb structures 4-1 and 4-2 located at both ends of the first honeycomb structure group 4A. The electrode 8 is disposed as the first electrode, and the electrode 9 is disposed as the second electrode. Further, the honeycomb structures 4-3 and 4-4 constitute the second honeycomb structure group 4B, and the honeycomb structures 4-3 and 4-4 positioned at both ends of the second honeycomb structure group 4B. The electrode 9 is disposed as the first electrode, and the electrode 10 is disposed as the second electrode. The electrodes 8 to 10 are made of metal mesh so that the gas GS to be processed passes therethrough.

  In the first honeycomb structure group 4A, a high voltage from a high voltage power source (high voltage source) 5-1 is applied between the first electrode 8 and the second electrode 9 via the conductive wires 11 and 12. Accordingly, in the second honeycomb structure group 4B, the high voltage power source (high voltage source) 5-2 is connected between the first electrode 9 and the second electrode 10 via the conducting wires 12 and 13. By applying a high voltage, plasma is generated in the through holes 4a of the honeycomb structure 4 and the space 14 (14-1, 14-2) between the honeycomb structures 4, and ions or radicals generated in the plasma are generated. Thus, the harmful gas contained in the processing target gas GS is decomposed into harmless substances.

  In this gas processing apparatus, when attention is paid to moisture (humidity) in the processing target gas GS, each of the processing target gases GS flows from the upstream side honeycomb structure 4 toward the downstream side honeycomb structure 4 in each process. Although the treatment is performed by the plasma discharge generated in the honeycomb structure 4, the moisture contained in the treatment target gas GS is consumed every time the treatment is received, so that the humidity of the treatment target gas GS decreases from the upstream side to the downstream side. It becomes a state. In addition, the plasma generation state inside the honeycomb structure 4 is more actively performed as the moisture in the gas GS to be processed increases, and has a characteristic of being suppressed when the moisture decreases.

  Here, if there is too much moisture in the gas GS to be processed, excessive plasma may be generated, causing abnormal discharge. When abnormal discharge occurs, the honeycomb structure 4 itself is damaged and damaged. Therefore, Patent Documents 4 and 5 show a configuration in which the occurrence of abnormal discharge is detected and the application of a high voltage is cut off.

JP 2000-140562 A JP 2001-276561 A JP 2008-194670 A JP 2008-245739 A JP-A-9-99254

  When the configurations shown in Patent Documents 4 and 5 are applied to the gas processing apparatus shown in FIG. 7, the first honeycomb structure group 4A side is defined as the first gas processing unit GU1, and the second honeycomb structure group. The gas processing unit that detects the occurrence of abnormal discharge by detecting the occurrence of abnormal discharge in each of the first gas processing unit GU1 and the second gas processing unit GU2 as the second gas processing unit GU2 on the 4B side For only, the configuration is such that application of a high voltage is cut off.

  However, in this case, the gas processing in the remaining gas processing unit is continued while stopping the gas processing in the gas processing unit that has detected the occurrence of abnormal discharge, but the overall gas processing capacity is reduced. However, there is a problem that the treatment cannot be performed sufficiently and untreated gas remains.

  The present invention has been made in order to solve such a problem. The object of the present invention is to continue the gas treatment while compensating for the decrease in the gas treatment capacity while suppressing the occurrence of abnormal discharge, and untreated. An object of the present invention is to provide a gas processing apparatus capable of preventing gas from remaining.

  In order to achieve such an object, the present invention provides an abnormal discharge detecting means for detecting that an abnormal discharge has occurred for each gas processing unit, and when abnormal discharge is detected by the abnormal discharge detecting means, Gas processing capability control means for reducing the gas processing capability of the gas processing unit in which the occurrence of discharge has been detected and increasing the gas processing capability of the gas processing unit in which the occurrence of abnormal discharge has not been detected is provided.

  In the present invention, in place of the abnormal discharge detection means, the most upstream unit abnormal discharge detection means for detecting only the occurrence of abnormal discharge of the gas processing unit installed in the uppermost stream in the passage direction of the gas to be processed is provided, and the gas If the occurrence of abnormal discharge is detected by the uppermost stream unit abnormal discharge detection means instead of the processing capacity control means, the gas processing capacity of the gas processing unit installed at the uppermost stream is lowered and the gas processing of other gas processing units is performed. Gas processing capacity control means for increasing the capacity may be provided.

  Further, in the present invention, the definition of reducing the gas processing capacity includes making the gas processing capacity zero (the amount of plasma generated is zero). Further, as a method of increasing / decreasing the gas processing capacity, a method of increasing / decreasing the voltage value of the applied high voltage, increasing / decreasing the frequency of the applied high voltage, increasing / decreasing the time of the applied high voltage, etc. Can be considered.

  According to the present invention, when the occurrence of abnormal discharge is detected, the gas processing capacity of the gas processing unit in which the occurrence of abnormal discharge is detected is lowered, and the gas processing of the gas processing unit in which the occurrence of abnormal discharge has not been detected. Since the capacity is increased, it is possible to continue the gas processing while suppressing the decrease in the gas processing capacity while suppressing the occurrence of abnormal discharge, so that no untreated gas remains.

  Further, according to the present invention, when the occurrence of abnormal discharge in the gas processing unit installed in the uppermost stream is detected, the gas processing capacity of the gas processing unit installed in the uppermost stream is lowered, and the other gas processing units Since the gas processing capacity has been increased, the simplified configuration that only monitors the abnormal discharge of the gas processing unit installed in the uppermost stream, while suppressing the occurrence of abnormal discharge and compensating for the decrease in gas processing capacity It is possible to continue the processing so that no untreated gas remains.

It is a figure which shows the principal part of one Embodiment (Embodiment 1) of the gas processing apparatus which concerns on this invention. It is a figure which shows the structure of the principal part of the abnormal discharge detection part in this gas processing apparatus. It is a figure which shows the principal part of other embodiment (Embodiment 2) of the gas processing apparatus which concerns on this invention. It is a figure which shows the structure at the time of only monitoring the abnormal discharge in the most upstream gas processing unit in Embodiment 1. FIG. It is a figure which shows the structure at the time of only monitoring the abnormal discharge in the most upstream gas processing unit in Embodiment 2. FIG. It is a figure which illustrates the principal part of the conventional gas processing apparatus using discharge plasma. It is a figure which shows the principal part of the gas processing apparatus shown by patent document 3. FIG.

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

[Embodiment 1]
FIG. 1 is a diagram showing a main part of an embodiment (Embodiment 1) of a gas processing apparatus according to the present invention. In this figure, the same reference numerals as those in FIG. 7 denote the same or equivalent components as those described with reference to FIG.

  Also in this embodiment, the first gas processing unit GU1 extends along the direction in which the gas to be processed GS passes (direction from the inlet of the duct 1 to the outlet) in the same manner as the gas processing apparatus shown in FIG. The second gas processing unit GU2 is disposed in the duct 1.

  However, in this embodiment, the high voltage V1 is applied between the electrodes 8 and 9 of the first gas processing unit GU1 via the high voltage application unit 15A, and the electrodes 9 and 10 of the first gas processing unit GU2 are connected. In the meantime, the high voltage V2 is applied via the high voltage application unit 15B.

  In addition, abnormal discharge in the gas processing unit GU1 is generated between the voltage supply terminals T1 and T2, that is, between the electrodes 8 and 9 of the first gas processing unit GU1 with respect to the high voltage application unit 15A. An abnormal discharge detection unit 16A for detection is provided, and the detection result of the abnormal discharge in the abnormal discharge detection unit 16A is sent to the control unit 17 as a detection signal S1A.

  In addition, abnormal discharge in the gas processing unit GU2 is generated between the voltage supply terminals T1 and T2, that is, between the electrodes 9 and 10 of the second gas processing unit GU2, with respect to the high voltage application unit 15B. An abnormal discharge detection unit 16B for detection is provided, and the detection result of the abnormal discharge in the abnormal discharge detection unit 16B is sent to the control unit 17 as a detection signal S1B.

  The control unit 17 is realized by hardware including a processor and a storage device, and a program that realizes various functions in cooperation with these hardware, and to the gas processing units GU1 and GU2 as a function unique to the present embodiment. Has a function of controlling the voltage values of the high voltages V1 and V2. A high voltage value control command from the control unit 17 to the gas processing units GU1 and GU2 is given to the high voltage application units 15A and 15B as S2A and S2B.

  FIG. 2 shows a configuration of a main part of the abnormal discharge detector 16 (16A, 16B). The abnormal discharge detection unit 16 includes a DC cut circuit 16-1, a discharge frequency detection circuit 16-2, a rectifying / smoothing circuit 16-3, and a level determination circuit 16-4. The DC cut circuit 16-1 is applied between the electrodes of the gas processing unit GU (GU1, GU2), that is, a high voltage generated between the voltage supply terminals T1 and T2 of the high voltage application unit 15 (15A, 15B). A high voltage is taken in, and a direct current component included in the high voltage is cut and output. The discharge frequency detection circuit 16-2 extracts a voltage of a predetermined frequency or more as a noise voltage generated by the discharge between the electrodes of the gas processing unit GU from the voltage obtained by cutting the DC component output from the DC cut circuit 16-1. The rectifying / smoothing circuit 16-3 rectifies and smoothes the noise voltage extracted from the discharge frequency detection circuit 16-2. The level determination circuit 16-4 determines the magnitude of the noise voltage rectified and smoothed by the rectifying and smoothing circuit 16-3, and indicates the occurrence of abnormal discharge when the magnitude of the noise voltage exceeds a predetermined value. Signal S1 (S1A, S1B) is output.

  In this embodiment, the electrode 9 is a common electrode that serves as both the second electrode of the gas processing unit GU1 and the first electrode of the gas processing unit GU2, but the second electrode of the gas processing unit GU1. The electrode and the first electrode of the gas processing unit GU2 may be independent electrodes.

[When abnormal discharge occurs in gas processing unit GU1]
In this gas processing apparatus, when an abnormal discharge occurs in the gas processing unit GU1, the abnormal discharge detection unit 16A sends a detection signal S1A indicating the occurrence of the abnormal discharge to the control unit 17.

  When the detection signal S1A indicating the occurrence of abnormal discharge in the gas processing unit GU1 is sent from the abnormal discharge detection unit 16A, the control unit 17 checks whether or not abnormal discharge has occurred in the gas processing unit GU2. That is, the detection signal S1B from the abnormal discharge detector 16B is checked, and if the detection signal S1B is not generated, it is determined that no abnormal discharge has occurred in the gas processing unit GU2.

  If an abnormal discharge has not occurred in the gas processing unit GU2, the control unit 17 sends a command S2A for lowering the voltage value of the high voltage V1 to the gas processing unit GU1 to the high voltage application unit 15A, and sends it to the high voltage application unit 15B. A command S2B for increasing the voltage value of the high voltage V2 is sent to the gas processing unit GU2.

  Thereby, the gas processing capability of the gas processing unit GU1 is lowered, and the occurrence of abnormal discharge in the gas processing unit GU1 is suppressed. Further, the gas processing capacity of the gas processing unit GU2 is increased, and a decrease in the gas processing capacity of the gas processing unit GU1 is compensated.

[When abnormal discharge occurs in gas processing unit GU2]
In this gas processing apparatus, when an abnormal discharge occurs in the gas processing unit GU2, the abnormal discharge detection unit 16B sends a detection signal S1B indicating the occurrence of the abnormal discharge to the control unit 17.

  When the detection signal S1B indicating the occurrence of abnormal discharge in the gas processing unit GU2 is sent from the abnormal discharge detection unit 16B, the control unit 17 checks whether or not abnormal discharge has occurred in the gas processing unit GU1. That is, the detection signal S1A from the abnormal discharge detector 16A is checked, and if the detection signal S1A is not generated, it is determined that no abnormal discharge has occurred in the gas processing unit GU1.

  If an abnormal discharge has not occurred in the gas processing unit GU1, the control unit 17 sends a command S2B for lowering the voltage value of the high voltage V2 to the gas processing unit GU2 to the high voltage applying unit 15B, and sends it to the high voltage applying unit 15A. A command S2A for increasing the voltage value of the high voltage V1 is sent to the gas processing unit GU1.

  Thereby, the gas processing capacity of the gas processing unit GU2 is lowered, and the occurrence of abnormal discharge in the gas processing unit GU2 is suppressed. Further, the gas processing capacity of the gas processing unit GU1 is increased, and a decrease in the gas processing capacity of the gas processing unit GU2 is compensated.

[Embodiment 2]
FIG. 3 is a view showing a main part of another embodiment (Embodiment 2) of the gas treatment apparatus according to the present invention. Also in this embodiment, as in the first embodiment, the first gas processing unit GU1 and the second gas are arranged along the direction in which the processing target gas GS passes (direction from the inlet to the outlet of the duct 1). The processing unit GU2 is arranged in the duct 1.

  However, in this embodiment, the first gas processing unit GU1 and the second gas processing unit GU2 are spaced apart from each other by a plurality of honeycomb structures 4 along the direction orthogonal to the passing direction of the processing target gas GS. The structure is provided and arranged.

  The first gas processing unit GU1 includes honeycomb structures 4-11 to 4-14, and a gap G1 is provided between the honeycomb structures 4-11 and 4-12, so that the honeycomb structures 4-13 and 4 are provided. It is arranged in the duct 1 with a gap G <b> 2 between −14.

  Also, among the honeycomb structures 4-11 to 4-14, the adjacent honeycomb structures 4-11 and 4-12 serve as the first honeycomb structure group 4A, and the both ends of the first honeycomb structure group 4A. Outside the honeycomb structures 4-11 and 4-12 positioned, the electrode 8-1 is disposed as the first electrode, and the electrode 9-1 is disposed as the second electrode.

  Further, among the honeycomb structures 4-11 to 4-14, the adjacent honeycomb structures 4-13 and 4-14 serve as a second honeycomb structure group 4B, and are disposed at both ends of the second honeycomb structure group 4B. Outside the honeycomb structures 4-13 and 4-14 located, the electrode 9-1 is disposed as the first electrode, and the electrode 10-1 is disposed as the second electrode.

  In the first gas processing unit GU1, the gap G1 between the honeycomb structures 4-11 and 4-12 and the gap G2 between the honeycomb structures 4-13 and 4-14 are determined by the processing target gas GS. It is gradually narrowed from the upstream side to the downstream side in the passing direction.

  In this example, the thickness of the honeycomb structures 4-12 and 4-13 is increased from the upstream side to the downstream side in the passage direction of the processing target gas GS, and the honeycomb structure 4-12 formed thereby. The inclined surface 4-12s of the electrode 9-1 is directed toward the honeycomb structure 4-11, the inclined surface 4-13s of the honeycomb structure 4-13 is directed toward the honeycomb structure 4-14, and the upper and lower surfaces of the electrode 9-1 By disposing the honeycomb structures 4-12 and 4-13, the intervals G1 and G2 are gradually narrowed from the upstream side to the downstream side in the passing direction of the processing target gas GS.

  The second gas processing unit GU2 includes honeycomb structures 4-21 to 4-24, and a gap G3 is provided between the honeycomb structures 4-21 and 4-22 so that the honeycomb structures 4-23 and 4 are provided. It is arranged in the duct 1 with a gap G4 between it and -24.

  Further, among the honeycomb structures 4-21 to 4-24, the adjacent honeycomb structures 4-21 and 4-22 constitute a first honeycomb structure group 4C, and the both ends of the first honeycomb structure group 4C. Outside the honeycomb structures 4-21 and 4-22 positioned, the electrode 8-2 is disposed as the first electrode, and the electrode 9-2 is disposed as the second electrode.

  Further, among the honeycomb structures 4-21 to 4-24, the adjacent honeycomb structures 4-23 and 4-24 are used as the second honeycomb structure group 4D, and the two honeycomb structures 4D are disposed at both ends of the second honeycomb structure group 4D. Outside the honeycomb structures 4-23 and 4-24, the electrode 9-2 is disposed as the first electrode, and the electrode 10-2 is disposed as the second electrode.

  In the second gas processing unit GU2, the gap G3 between the honeycomb structures 4-21 and 4-22 and the gap G4 between the honeycomb structures 4-23 and 4-24 have the same thickness. By using the honeycomb structures 4-21 to 4-24, the intervals are equal.

  In this gas processing apparatus, the processing target gas GS is caused to flow into the duct 1, and between the electrodes 8-1 and 9-1 and between the electrodes 9-1 and 10-1 of the first gas processing unit GU1, The high voltage V1 from the high voltage application unit 15A is individually applied. Further, the high voltage V2 from the high voltage application unit 15B is individually applied between the electrodes 8-2 and 9-2 and between the electrodes 9-2 and 10-2 of the second gas processing unit GU2. .

  Also in the second embodiment, as in the first embodiment, an abnormal discharge detection unit 16A that detects the occurrence of abnormal discharge in the first gas processing unit GU1 is provided for the high voltage application unit 15A. The detection result of the abnormal discharge in the discharge detection unit 16A is sent to the control unit 17 as the detection signal S1A. In addition, an abnormal discharge detection unit 16B that detects the occurrence of abnormal discharge in the second gas processing unit GU2 is provided for the high voltage application unit 15B, and the detection result of the abnormal discharge in the abnormal discharge detection unit 16B is detected. The information is sent to the control unit 17 as S1B.

  When the detection signal S1A indicating the occurrence of abnormal discharge in the gas processing unit GU1 is sent from the abnormal discharge detection unit 16A, the control unit 17 confirms that no abnormal discharge has occurred in the gas processing unit GU2. In addition, a command S2A for lowering the voltage value of the high voltage V1 to the gas processing unit GU1 is sent to the high voltage application unit 15A, and a command S2B for raising the voltage value of the high voltage V2 to the gas processing unit GU2 is sent to the high voltage application unit 15B. send.

  Thereby, the gas processing capability of the gas processing unit GU1 is lowered, and the occurrence of abnormal discharge in the gas processing unit GU1 is suppressed. Further, the gas processing capacity of the gas processing unit GU2 is increased, and a decrease in the gas processing capacity of the gas processing unit GU1 is compensated.

  When the detection signal S1B indicating the occurrence of abnormal discharge in the gas processing unit GU2 is sent from the abnormal discharge detection unit 16B, the control unit 7 confirms that no abnormal discharge has occurred in the gas processing unit GU1. In addition, a command S2B for lowering the voltage value of the high voltage V2 to the gas processing unit GU2 is sent to the high voltage application unit 15B, and a command S2B for raising the voltage value of the high voltage V1 to the gas processing unit GU1 is sent to the high voltage application unit 15A. send.

  Thereby, the gas processing capacity of the gas processing unit GU2 is lowered, and the occurrence of abnormal discharge in the gas processing unit GU2 is suppressed. Further, the gas processing capacity of the gas processing unit GU1 is increased, and a decrease in the gas processing capacity of the gas processing unit GU2 is compensated.

  In the second embodiment, in the gas processing units GU1 and GU2, the honeycomb structures 4 are arranged at intervals along the direction orthogonal to the passing direction of the processing target gas GS. The time during which the processing target gas GS is exposed to plasma in the through holes 4a of the honeycomb structures 4 and the spaces 14 between the honeycomb structures 4 is longer than when the gas GS is disposed along the passage direction of the gas GS. As a result, the opportunity for gas decomposition is increased, the gas processing capacity is improved, and it is possible to prevent a decrease in gas processing capacity in a high-speed flow.

  In the second embodiment, in the gas processing units GU1 and GU2, the high voltage applying unit 15A is provided between the electrodes of the first honeycomb structure groups 4A and 4C and between the electrodes of the second honeycomb structure groups 4B and 4C. Since the high voltages V1 and V2 from 15B are individually applied, the potentials in the spaces 14-1, 14-2, 14-3 and 14-4 are stably maintained in a high electric field state, and the plasma is stabilized. Can be generated.

  Further, in the second embodiment, in the gas processing unit GU1, the intervals G1 and G2 between the honeycomb structures 4 forming the spaces 14-1 and 14-2 are set downstream from the upstream side in the passing direction of the processing target gas GS. The gaps G1 and G2 between the honeycomb structures 4 are widened on the upstream side where the plasma generation conditions are good, and are narrowed on the downstream side where the plasma generation conditions are bad. The generation state of the plasma on the downstream side is balanced, and the gas processing capacity is stabilized.

  In the first and second embodiments described above, when an abnormal discharge occurs in the gas processing unit GU1, the voltage value of the high voltage V1 to the gas processing unit GU1 is lowered and the voltage of the high voltage V2 to the gas processing unit GU2 is reduced. When an abnormal discharge occurs in the gas processing unit GU2, the voltage value of the high voltage V2 to the gas processing unit GU2 is decreased and the voltage value of the high voltage V1 to the gas processing unit GU1 is increased. The range of increase and decrease in the voltage value may be a predetermined constant value, or may be changed according to the amount of occurrence of abnormal discharge. Alternatively, application of a high voltage to the gas processing unit in which abnormal discharge has occurred may be cut off, and the gas processing capacity of the gas processing unit may be set to zero (the amount of plasma generated is zero).

  In the first and second embodiments described above, the gas processing capacity of the gas processing units GU1, GU2 is increased / decreased by increasing / decreasing the voltage value of the applied high voltage. The gas processing capacity of the gas processing units GU1 and GU2 may be increased / decreased in length / short. Alternatively, the high voltage to be applied may be alternating current, and the gas processing capability of the gas processing units GU1, GU2 may be increased / decreased by increasing / decreasing the frequency of the alternating high voltage.

  In the first and second embodiments described above, abnormal discharge detectors 16A and 16B are provided for the high voltage application units 15A and 15B, respectively, and the occurrence of abnormal discharge in the gas processing units GU1 and GU2 is detected. However, as shown in FIG. 4 and FIG. 5, it may be configured to only detect the occurrence of abnormal discharge in the most upstream gas processing unit GU1.

  In this configuration, when the detection signal S1A indicating the occurrence of abnormal discharge in the gas processing unit GU1 is sent from the abnormal discharge detection unit 16A to the control unit 17, the control unit 17 immediately sends the high voltage application unit 15A to the gas processing unit GU1. A command S2A for lowering the voltage value of the high voltage V1 is sent, and a command S2B for raising the voltage value of the high voltage V2 to the gas processing unit GU2 is sent to the high voltage application unit 15B.

  That is, the gas processing unit that has a high possibility of causing abnormal discharge is the gas processing unit GU1 installed in the uppermost stream with a large amount of moisture in the processing target gas GS, and therefore, only abnormal discharge in the gas processing unit GU1 is monitored. Even if it just does, gas processing can be continued, compensating for the fall of gas processing capacity. By doing so, monitoring of abnormal discharge in the gas processing unit GU2 can be omitted, and the gas processing apparatus can be simplified.

 In the first and second embodiments described above, the honeycomb structure 4 may be provided with a catalyst function for decomposing ozone, and a catalyst for decomposing ozone is provided at a downstream position in the passing direction of the processing target gas GS. It may be.

  Moreover, in Embodiment 1 and 2 mentioned above, although the number of gas processing units was two, you may make it increase the number further. In the first embodiment, the number of honeycomb structures in the gas treatment unit is not limited to two, and the number may be further increased. In the second embodiment, the number of honeycomb structure groups in the gas treatment unit may be one, and the number may be further increased. Further, the number of honeycomb structures in the honeycomb structure group is not limited to two.

  Further, in the first and second embodiments described above, a large amount of ozone may be generated as a by-product and used as an ozone generator.

The gas processing apparatus of the present invention can also be applied to so-called reforming for generating a hydrogen-containing gas 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 (substance relatively close to the average molecular weight of gasoline) C ₈ H ₁₈ , when supplied to this gas treatment device, the chemical reaction represented by the following formula (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)

  DESCRIPTION OF SYMBOLS 1 ... Duct (ventilation path), 4 (4-1 to 4-4, 4-11 to 4-14, 4-21 to 4-24) ... Honeycomb structure, 4a ... Through-hole (cell), 4-12s , 4-13s ... inclined surface, 4A to 4D ... honeycomb structure group, 8 (8-1, 8-2), 9 (9-1, 9-2), 10 (10-1, 10-2) ... Electrode, 11, 12, 13 ... conducting wire, 14 (14-1 to 14-4, 14-11 to 14-14, 14-21 to 14-24) ... space, 15 (15A, 15B) ... high voltage application unit , 16 (16A, 16B) ... abnormal discharge detection unit, 16-1 ... DC cut circuit, 16-2 ... discharge frequency detection circuit, 16-3 ... rectification smoothing circuit, 16-4 ... level determination circuit, 17 ... control unit , G (G1 to G4) ... interval, GS ... gas to be processed, GU (GU1, GU2) ... gas processing unit.

Claims (3)

A plurality of honeycomb structures having a large number of through-holes that are arranged at intervals in the ventilation path and through which the gas to be processed flowing through the ventilation path passes;
A plurality of adjacent honeycomb structures among the plurality of honeycomb structures are regarded as a group of honeycomb structures, and the first and second arranged on the outside of the honeycomb structures located at both ends of the honeycomb structures . Electrodes,
A gas processing unit comprising a high voltage source for applying a high voltage between the first electrode and the second electrode to generate plasma in the through hole of the honeycomb structure and the space between the honeycomb structures In the gas processing apparatus in which a plurality of the gas to be processed is installed along the passage direction of the processing target gas,
Abnormal discharge detection means for detecting that an abnormal discharge has occurred for each gas processing unit;
When occurrence of abnormal discharge is detected by the abnormal discharge detection means, the gas processing capacity of the gas processing unit in which the occurrence of abnormal discharge is detected is lowered, and the gas processing in the gas processing unit in which occurrence of abnormal discharge is not detected A gas processing apparatus comprising: gas processing capacity control means for increasing capacity. A plurality of honeycomb structures having a large number of through holes arranged at intervals along a direction orthogonal to the passage direction of the processing target gas from the inlet to the outlet of the ventilation path, and through which the processing target gas passes;
A plurality of adjacent honeycomb structures among the plurality of honeycomb structures are regarded as a group of honeycomb structures, and each of the honeycomb structures is disposed outside the honeycomb structures positioned at both ends thereof. Two electrodes;
A high voltage source for generating a plasma in a through hole of the honeycomb structure and a space between the honeycomb structures by individually applying a high voltage between the first electrode and the second electrode of each honeycomb structure group In a gas processing apparatus in which a plurality of gas processing units comprising:
Abnormal discharge detection means for detecting that an abnormal discharge has occurred for each gas processing unit;
When occurrence of abnormal discharge is detected by the abnormal discharge detection means, the gas processing capacity of the gas processing unit in which the occurrence of abnormal discharge is detected is lowered, and the gas processing in the gas processing unit in which occurrence of abnormal discharge is not detected A gas processing apparatus comprising: gas processing capacity control means for increasing capacity. In the gas treatment device according to claim 1 or 2,
Instead of the abnormal discharge detection means,
The most upstream unit abnormal discharge detection means for detecting only the occurrence of abnormal discharge of the gas processing unit installed in the uppermost stream in the passing direction of the processing target gas,
Instead of the gas processing capacity control means,
Gas processing capability that lowers the gas processing capability of the gas processing unit installed in the uppermost stream and increases the gas processing capability of other gas processing units when the occurrence of abnormal discharge is detected by the uppermost stream unit abnormal discharge detection means A gas processing apparatus comprising a control means.

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