Patents

Engine Emission Exhaust System

PATENT ABSTRACTS OF JAPAN

(54) EXHAUST EMISSION CONTROL DEVICE

(57)Abstract:PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of exerting a high NOx reducing performance immediately from the stage at which the exhaust gas temperature has reached the active temperature zone of a selective reduction type catalyst, even at engine start in low speed running, etc. with a low exhaust gas temperature.

SOLUTION: The exhaust emission control device includes a urea electric discharge decomposing reactor 14 equipped with a ground electrode 16 (first electrode) formed in a drum shape whose outer peripheral surface is covered with a porous ceramic 15 as a dielectric substance, a high voltage electrode 19 (second electrode) having a form of a number of needles facing the outer peripheral surface of the drum, a rotary motor 17 (driving means) to rotate the ground electrode 16, a dust feeder 22 (urea supplying means) to feed the urea dust 13 (urea raw material) to under the outer peripheral surface of the ground electrode 16 to cause attaching thereto, and a transport gas line 26 to send out the ammonia produced in the electric discharge space 27 into an exhaust pipe with the aid of a compressed air 25 (transport gas). The reactor 14 is installed upstream of the selective reduction type catalyst.