Particulate trap for diesel engine

摘要

A particulate trap for a diesel engine comprising: a metallic main filter having an average pore diameter of 10 mu m to 80 mu m and a metallic pre-filter having an average pore diameter of more than 80 mu m but not more than 300 mu m. The main filter is preferably so structured spirally and constituted of metallic unwoven fabrics having a metallic corrugated sheet therebetween layers of the metallic unwoven fabrics. The use of the pre-filter in combination with the main filter makes it possible to selectively collect the ash from the exhaust gas by the pre-filter and prevent the clogging of the metallic main filter, thereby achieving a long term use of the particulate trap.