| 摘要 |
One embodiment of the present invention permits production of the complete monolithic cross flow trap module in a single extrusion process followed by firing to sinter the plasticized ceramic material and remove the plastics to achieve open porosity. Consequently, the trap modules can be made in large production quantities at minimal cost. A second embodiment for an apparatus and method of manufacturing for a monolithic cross flow trap requires more production steps but permits the manufacture of the monolithic trap modules in large sizes and various configurations with minimal change in tooling. The preferred material for all of the trap designs and methods of manufacture is plasticized ceramic that, following extrusion or assembly is fired to sinter the material and provide open porosity. However, the traps could be made of other refractory plasticized ceramics or even plasticized powder metals. The designs and manufacturing processes permit the production of trap modules that have large internal surface areas in the plurality of porous tubular passages and this will provide excellent filtration efficiency with minimal pressure drop for a given trap module overall size. These parameters are at least equal to those of the well-known monolithic honeycomb wall-flow trap that is prone to poor reliability and short life. Thus, a particulate trap system that uses these trap modules can be compact without creating excessive engine back pressure that would adversely affect engine performance. In common with the better known honeycomb wall-flow traps, the cross flow designs will eliminate the need for any other separate exhaust muffler.
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