Exhaust gas purification method and exhaust gas purification system

Abstract

In order to remove by burning captured PM by using microscopic luminescent discharge that repeats generation and extinction randomly in time and space on the surface of an insulating filter with a minimum power consumption and to enhance the capturing efficiency and combustion-removal efficiency of PM in exhaust gas from diesel engines or the like, at least one electrode pair ( 13 ) are arranged on or in the vicinity of the surface of an insulating capturing member ( 12 ) for capturing particulate matter ( 41 ) in exhaust gas, a predetermined voltage (Vs) is applied between the electrode pair ( 12 ) to generate a microscopic luminescent discharge ( 42 ) that repeats generation and extinction randomly in time and space on the surface of the insulating capturing member ( 12 ), and the microscopic luminescent discharge ( 42 ) generated by the application of this predetermined voltage (Vs) is used to remove by burning the particulate matter ( 41 ) captured on the insulating capturing member ( 12 ).

1 . An exhaust gas purification method wherein
 arranging at least one electrode pair on the surface or in the vicinity of the surface of an insulating capturing member that captures particulate matter in exhaust gas;   applying, between the electrode pair, a predetermined voltage that generates a microscopic luminescent discharge that repeats generation and extinction randomly in time and space on the surface of the insulating capturing member according as the accumulated amount of the particulate matter captured on the surface of the insulating capturing member increases; and   removing the particulate matter captured in the insulating capturing member through burning by the microscopic luminescent discharge that was generated by the application of a predetermined voltage   
   
   
       2 . The exhaust gas purification method according to  claim 1 , wherein the insulating capturing member is an insulating filter through which exhaust gas including particulate matter passes and which captures particulate matter. 
   
   
       3 . The exhaust gas purification system comprising:
 an insulating capturing member that captures particulate matter in exhaust gas;   at least one electrode pair arranged on the surface or in the vicinity of the surface of the insulating capturing member; and   a voltage applying device that applies a predetermined voltage between the electrode pair, wherein   the voltage applying device applies predetermined voltage that generates a microscopic luminescent discharge that repeats generation and extinction randomly in time and space on the surface of the insulating capturing member according as the accumulated amount of the particulate matter captured on the surface of the insulating capturing member increases.   
   
   
       4 . The exhaust gas purification system according to  claim 3 , wherein the insulating capturing member is an insulating filter through which exhaust gas including particulate matter passes and which captures particulate matter. 
   
   
       5 . The exhaust gas purification system according to  claim 3  or  4 , wherein the predetermined voltage is a voltage in the area where the relation of electrical current and voltage between the electrodes is in non-linear. 
   
   
       6 . The exhaust gas purification system according to any one of  claim 3  or  4 , wherein the charging means, which charges particulate matter in exhaust gas, is arranged on the upstream side of the insulating capturing member. 
   
   
       7 . The exhaust gas purification system according to  claim 4 , wherein the insulating capturing member is formed with a ceramic fiber filter. 
   
   
       8 . The exhaust gas purification system according to  claim 3  or  4 , wherein the insulating capturing member carries an oxidation catalyst. 
   
   
       9 . The exhaust gas purification system according to  claim 3  or  4 , wherein the oxidation catalyst is arranged on the upstream side or downstream side of the insulating capturing member.