GAS PURIFYING DEVICE, GAS PURIFYING SYSTEM AND GAS PURIFYING METHOD

• US 20100072055A1
• Filed: 11/19/2007
• Published: 03/25/2010
• Est. Priority Date: 11/20/2006
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yasui, Hiroyuki, Tanaka, Motofumi
• Application Number:
  US12/515,547
• Publication Number:
  US 20100072055A1
• Time in Patent Office: Days
• US Class Current: 204/164
• CPC Class Codes: B01D 2255/102 Platinum group metals
• CPC Class Codes: B01D 2255/40 Mixed oxides
• CPC Class Codes: B01D 2255/908 O2-storage component incorporated in the catalyst
• CPC Class Codes: B01D 2258/01 Engine exhaust gases
• CPC Class Codes: B01D 2259/818 Employing electrical discharges or the generation of a plasma
• CPC Class Codes: B01D 53/32 by electrical effects other than those provided for in group B01D61/00
• CPC Class Codes: B01D 53/922 Mixtures of carbon monoxide or hydrocarbons and nitrogen oxides
• CPC Class Codes: B03C 2201/12 Cleaning the device by burning the trapped particles
• CPC Class Codes: B03C 2201/24 for measuring or calculating parameters, efficiency, etc.
• CPC Class Codes: B03C 2201/30 for use in or with vehicles
• CPC Class Codes: B03C 3/017 Combinations of electrostatic separation with other processes, not otherwise provided for
• CPC Class Codes: B03C 3/025 Combinations of electrostatic separators, e.g. in parallel or in series, stacked separators, dry-wet separator combinations
• CPC Class Codes: B03C 3/08 characterised by presence of stationary flat electrodes arranged with their flat surfaces parallel to the gas stream
• CPC Class Codes: B03C 3/12 characterised by separation of ionising and collecting stations
• CPC Class Codes: B03C 3/366 located in the filter, e.g. special shape of the electrodes
• CPC Class Codes: B03C 3/47 flat, e.g. plates, discs, gratings
• CPC Class Codes: B03C 3/60 Use of special materials other than liquids
• CPC Class Codes: B03C 3/66 Applications of electricity supply techniques
• CPC Class Codes: B03C 3/68 Control systems therefor electricity supply or control systems for cleaning the electrodes B03C3/746, B03C3/763
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 13/011 : having two or more purifying devices arranged in parallel
• CPC Class Codes: F01N 13/017 : the purifying devices are arranged in a single housing
• CPC Class Codes: F01N 2240/28 : a plasma reactor
• CPC Class Codes: F01N 3/0275 : using electric discharge means
• CPC Class Codes: F01N 3/035 : with catalytic reactors , e.g. catalysed diesel particulate filters

Abstract

A gas purifying device (10) includes a first electric field forming unit which forms an electric field for discharge in a gas channel (36) in which a purification target gas (EG) flows to generate a discharge plasma (P), and charges and burns PM included in the purification target gas (EG) by action of the discharge plasma (P), a second electric field forming unit which forms an electric field for dust collection to capture the charged PM by an electrical dust collection function and draw out the discharge plasma (P) to the gas channel side, and a charge electrode (35) for charging a flowing purification target gas (EG), which is disposed on an upstream side positions where the first electric field forming unit and the second electric field forming unit are disposed.

Claims

1. A gas purifying device having a first electric field forming unit which forms an electric field for discharge in a gas channel in which a purification target gas flows to generate a discharge plasma, and charges and burns particulate matter included in the purification target gas by action of the discharge plasma, and a second electric field forming unit which forms an electric field for dust collection to capture the charged particulate matter by an electrical dust collection function and draw out the discharge plasma to the gas channel side,

the device, comprising,

a charge electrode for charging a flowing purification target gas, which is disposed on an upstream side of positions where the first electric field forming unit and the second electric field forming unit are disposed.

2. The gas purifying device according to claim 1,

wherein the charge electrode is disposed in a direction substantially perpendicular to a main flow direction of the purification target gas.

3. The gas purifying device according to claim 1, further comprising,

a plurality of the charge electrodes disposed at predetermined intervals.

11. A gas purifying system, comprising,

at least two gas purifying devices according to claim 1 arranged in series or parallel.

15. The gas purifying system according to claim 11, further comprising,

a switching valve capable of switching and introducing a flow of a purification target gas to each of the gas purifying devices, when the gas purifying devices are arranged in parallel.

4. A gas purifying device having a first electric field forming unit which forms an electric field for discharge in a gas channel in which a purification target gas flows to generate a discharge plasma, and charges and burns particulate matter included in the purification target gas by action of the discharge plasma, and a second electric field forming unit which forms an electric field for dust collection to capture the charged particulate matter by an electrical dust collection function and draw out the discharge plasma to the gas channel side,

wherein at least one of an inner wall face of the gas channel on a side where the first electric field forming unit is disposed, an inner wall face of the gas channel on a side where the second electric field forming unit is disposed, a discharge electrode forming the first electric field forming unit, and a dust collection electrode forming the second electric field forming unit has a surface formed of a recess and projection face.

5. The gas purifying device according to claim 4,

wherein recesses and projections of the recess and projection face are formed along a main flow direction of the purification target gas.

6. The gas purifying device according to claim 4,

wherein recesses and projections of the recess and projection face are formed along a direction substantially perpendicular to a main flow direction of the purification target gas.

12. A gas purifying system, comprising,

at least two gas purifying devices according to claim 4 arranged in series or parallel.

16. The gas purifying system according to claim 12, further comprising,

a switching valve capable of switching and introducing a flow of a purification target gas to each of the gas purifying devices, when the gas purifying devices are arranged in parallel.

7. A gas purifying device having a first electric field forming unit which forms an electric field for discharge in a gas channel in which a purification target gas flows to generate a discharge plasma, and charges and burns particulate matter included in the purification target gas by action of the discharge plasma, and a second electric field forming unit which forms an electric field for dust collection to capture the charged particulate matter by an electrical dust collection function and draw out the discharge plasma to the gas channel side,

wherein a catalyst layer is formed on a surface of at least one of an inner wall face of the gas channel on a side where the first electric field forming unit is disposed, an inner wall face of the gas channel on a side where the second electric field forming unit is disposed, a discharge electrode forming the first electric field forming unit, and a dust collection electrode forming the second electric field forming unit.

8. The gas purifying device according to claim 7,

wherein the catalyst layer is formed of a coating layer of a catalyst material coated on the surface.

9. The gas purifying device according to claim 7,

wherein the catalyst layer is formed of a porous layer carrying a catalyst material disposed on the surface.

13. A gas purifying system, comprising,

at least two gas purifying devices according to claim 7 arranged in series or parallel.

17. The gas purifying system according to claim 13, further comprising,

a switching valve capable of switching and introducing a flow of a purification target gas to each of the gas purifying devices, when the gas purifying devices are arranged in parallel.

10. A gas purifying device having a first electric field forming unit which forms an electric field for discharge in a gas channel in which a purification target gas flows to generate a discharge plasma, and charges and burns particulate matter included in the purification target gas by action of the discharge plasma, and a second electric field forming unit which forms an electric field for dust collection to capture the charged particulate matter by an electrical dust collection function and draw out the discharge plasma to the gas channel side,

the device, comprising,

an additive gas supply unit which supplies an additive gas capable of generating oxidative radicals on an upstream side of positions where the first electric field forming unit and the second electric field forming unit are disposed.

14. A gas purifying system, comprising,

at least two gas purifying devices according to claim 10 arranged in series or parallel.

18. The gas purifying system according to claim 14, further comprising,

a switching valve capable of switching and introducing a flow of a purification target gas to each of the gas purifying devices, when the gas purifying devices are arranged in parallel.

19. A gas purifying method for a gas purifying device comprising a first electric field forming unit which forms an electric field for discharge in a gas channel in which a purification target gas flows to generate a discharge plasma, and charges and burns particulate matter included in the purification target gas by action of the discharge plasma, a second electric field forming unit which forms an electric field for dust collection to capture the charged particulate matter by an electrical dust collection function and draw out the discharge plasma to the gas channel side, and a control unit controlling the first electric field forming unit and the second electric field forming unit,

the method, comprising,

by the control unit, detecting information related to burning treatment of particulate matter in the first electric field forming unit, and controlling an operation state of the first electric field forming unit and/or the second electric field forming unit based on the detected information.

21. The gas purifying method according to claim 19,

wherein the gas purifying device further comprises an additive gas supply unit which supplies an additive gas capable of generating oxidative radicals on an upstream side of the first electric field forming unit and the second electric field forming unit and a gas constituent detecting unit which detects gas constituents in a purification target gas,

the method, further comprising,

by the control unit, controlling the additive gas supply unit based on gas constituents detected by the gas constituent detecting unit to adjust a flow rate of an additive gas to be supplied into a purification target gas.

23. The gas purifying method according to claim 19,

wherein the information related to burning treatment of particulate matter includes at least one of gas constituent changes of the purification target gas at entrance and exit of the gas purifying device, pressure loss in the gas purifying device, temperature changes of the purification target gas at entrance and exit of the gas purifying device, and ratio of applied voltage to current in the first electric field forming unit or the second electric field forming unit.

20. A gas purifying method for a plurality of gas purifying devices arranged in series or parallel and each comprising a first electric field forming unit which forms an electric field for discharge in a gas channel in which a purification target gas flows to generate a discharge plasma, and charges and burns particulate matter included in the purification target gas by action of the discharge plasma, a second electric field forming unit which forms an electric field for dust collection to capture the charged particulate matter by an electrical dust collection function and draw out the discharge plasma to the gas channel side, and a control unit controlling the first electric field forming unit and the second electric field forming unit,

the method, comprising,

by the control unit, detecting information related to burning treatment of particulate matter in the first electric field forming unit in each of the gas purifying devices, and controlling an operation state of the first electric field forming unit and/or the second electric field forming unit based on the detected information in each of the gas purifying devices.

22. The gas purifying method according to claim 20,

wherein the gas purifying devices further comprise an additive gas supply unit which supplies an additive gas capable of generating oxidative radicals on an upstream side of the first electric field forming unit and the second electric field forming unit and a gas constituent detecting unit which detects gas constituents in a purification target gas,

the method, further comprising,

by the control unit, controlling the additive gas supply unit based on gas constituents detected by the gas constituent detecting unit to adjust a flow rate of an additive gas to be supplied into a purification target gas.

24. The gas purifying method according to claim 20,

wherein the information related to burning treatment of particulate matter includes at least one of gas constituent changes of the purification target gas at entrance and exit of the gas purifying device, pressure loss in the gas purifying device, temperature changes of the purification target gas at entrance and exit of the gas purifying device, and ratio of applied voltage to current in the first electric field forming unit or the second electric field forming unit.