Automatic purifying device for engine exhaust gases

Abstract

An automatic purifying device for engine exhaust gases is disclosed. Exhaust gases flow through a necked portion to be speeded and the temperature of the exhaust gases is kept uniform after entering an exhaust inlet, and the speeded exhaust gases then pass through a flared mouth so as to be diffused through metal catalyst carriers and a straight-through ceramic filter or wall-flow filter, allowing the poisonous emissions such as nitrogen oxides (NOx) to collide with the metal catalyst carriers to generate high heat to ignite carbon particles, carbon monoxide, hydrocarbons, and the like which are then decomposed and reduced to nitrogen gas and water by added urea or ammonia in the middle of passing through the straight-through ceramic filter or wall-flow filter, where the generated water can then be discharged through a drain port, thereby decreasing pollution to the environment.

I claim: 
     
         1 . An automatic purifying device for engine exhaust gases, comprising:
 an exhaust pipe, comprising an exhaust inlet and exhaust outlet positioned on two axial ends thereof and in communication with each other, a necked portion and flared mouth being configured in sequence between said exhaust inlet and exhaust outlet in an axial direction from said exhaust inlet toward said exhaust outlet, and said necked portion being smaller than said flared mouth in diameter;   a plurality of metal catalyst carriers, arranged axially in sequence behind said flared mouth; and   at least one straight-through ceramic filter, covered with ceramic wool and configured between said last arranged metal catalyst carrier and said exhaust outlet.   
     
     
         2 . The device according to  claim 1 , wherein an air intake allowing an inside of said exhaust pipe to be in communication with an outside thereof is configured on a wall of said neck portion. 
     
     
         3 . The device according to  claim 1 , wherein a drain port is configured on a wall of said exhaust pipe between one of said metal catalyst carriers and said straight-through ceramic filter, and a bolt adapted to close and open said drain port is configured on said drain port.