| 摘要 |
#CMT# #/CMT# An exhaust gas after-treatment device for diesel engines, comprises an electric heater (4) for spatially non-uniformly distributing thermal capacity. The electric heater is attached to catalyst unit(s) for activating a catalyst or improving a conversion efficiency of nitric oxide/nitrogen dioxide at a low temperature. #CMT# : #/CMT# Independent claims are also included for: (a) a method of manufacturing an electric heater used to purify exhaust gas from a vehicle and manufactured by stacking strips, comprising inserting the strips into a jig having strip insertion holes of prescribed shapes; and (b) an apparatus for forming a strip, comprising a driving source; a transferring unit operated by a power from the driving source for transferring a strip material; and at least two gears having gear teeth formed at prescribed parts of an outer circumference of gears, where corrugated strip parts and flat strip parts are alternately formed at the strip material by the gear teeth of the gears. #CMT#USE : #/CMT# For diesel engines. #CMT#ADVANTAGE : #/CMT# The inventive device is capable of burning the particulate matter contained in exhaust gas from the internal combustion engine, especially the diesel engine, so that pollutants are not discharged to the air. It has an effect of regenerating a filter through the electric heater even at a low temperature. The electric heater is used as an auxiliary heating source, where energy consumption is reduced as compared to the conventional exhaust gas after treatment device using the electric heater as a main heating source. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The figure is a side view, in section, of an exhaust gas purification system equipped with an electric heater that is applied to a catalyzed filter. 4 : Electric heater 8 : Catalyzed filter 10 : Radiant heat prevention unit 12 : Mat #CMT#MECHANICAL ENGINEERING : #/CMT# Preferred Component: The catalyst unit is a catalyzed filter (8). It comprises an oxidation catalyst and a catalyzed filter. The electric heater is disposed in front of the filter, preferably between the oxidation catalyst and the catalyzed filter. It is divided into a center segment and a surrounding segment. The surrounding segment comprises segment parts arranged radially around the center segment. The electric current is supplied continuously or selectively to the respective segments so that particulate matters collected at the segments are burned. The after treatment device further comprises mantles, where one mantle surrounding the center segment is connected to an anode and the mantles of the surrounding segment are connected to cathodes, respectively, so that entire power supply circuits are connected to each other in series or parallel; and a radiant heat prevention unit (10) disposed on the mantles and the strips. The center and surrounding segments are formed, respectively, by stacking strips. Each strip comprises corrugated parts, flat parts, and offset parts of a prescribed length. The corrugated and flat strip parts are alternately arranged. Each of the offset parts is disposed between the corrugated strip part and the neighboring flat strip part. The upper strip is stacked on the lower strip such that the corrugated strip part is formed at one side of each of the upper and lower strips, and the flat strip part is formed at the other side of each of the upper and lower strips, when a stacking process is carried out of the strips each formed by alternately arranging the corrugated strip parts and the flat strip parts. The height of the strip inserted into the mantle is changed to eliminate the interference between the electrodes and the heating elements so that the specific surface area is increased. The length of the mantle for the anode is smaller than the length of the mantle for the cathode. The electrode comprises an electrode rod having a bolt tap formed at one end, and an electrode ring containing a ceramic and securely fitted on the electrode rod. The electrode rod is attached to the mantle by the bolt tap. It has groove(s) formed on the outer circumference at the position where the electrode ring is fitted. The fixing of the mantle and the strip is carried out by the combination of a socket rest formed at a prescribed area of the strip and a socket inserted into the socket rest while the socket comes into contact with the mantle; or carried out through a joining pin. The radiant heat prevention unit is mounted using an insulation pin such that the radiant heat prevention unit is electrically insulated from the strip and the mantle. The insulation pin is inserted through a though-hole of a cylindrical ceramic member. It is divided into two insulation parts being disposed in the ceramic member while the insulation parts are spaced apart from each other. The electric heater is operated such that it supplies different amounts of heating energy on the basis of engine's five states: a low speed/high load state with engine torque of below 1800 rpm and engine load rate of 70-100 %, a low speed/low load state with engine torque of below 1800 rpm and engine load rate of 0 - 30 %, a middle speed/high load state with engine torque of 1800-3500 rpm and engine load rate of 70-100 %, a middle speed/middle load state with engine torque of 1800 - 3500 rpm and engine load rate of 30-70 %, and a high speed/low load state with engine torque of above 3500 rpm and engine load rate of 0 - 30 %. The jig further has mantle insertion hole(s) formed so that mantle(s) for supplying electric current to the strip is inserted into the mantle insertion hole. The strip forming apparatus further comprises cams fitted on shafts of the gears and rotated along with the shafts of the gears for adjusting the clearance between the gears. The gears are rotatably engaged with each other for forming corrugation at the strip material. Preferred Method: The method further comprises forming notches at an edge of the walls of the strip insertion holes and the mantle insertion hole. #CMT#INORGANIC CHEMISTRY : #/CMT# Preferred Material: The jig is made of a metal. #CMT#CERAMICS AND GLASS : #/CMT# Preferred Material: The jig is made of a ceramic. |
