| 摘要 |
The filter, connected after the exhaust catalytic converter, has a porous structure through which the treated gases pass, leaving sooty particles to accumulate on its upstream surfaces. A fuel additive reduces the self-combustion temperature of the soot to 400-500 deg.C. When heated above this temperature by heaters (46), the soot ignites. The self propagating quickly clears the whole contact surface, regenerating the filter. The e.g. cerium-based fuel additive from a supplementary tank is supplied to the fuel in proportions ranging from 5 to 250 ppm by weight. The cylindrical filter block (20), of ceramic or other porous material, contains an array of juxtaposed axial (XX) channels, alternately closed at the upstream (42B) and downstream (42A) ends. Gases flowing (F) into the upstream openings filter through the extensive surfaces of the separating walls to exit by the downstream ones. The block is housed in a metal case (30) with conical end sections (36,38) leading to pipe connections (32,34). Typically, 4 sockets (44) in the case accept heater plugs (22) initiating combustion in adjacent zones (48) on the block when energized by a controller responding to e.g. rising back-pressure due to soot clogging. |
