A diesel engine exhaust gas purification device

Abstract

The invention discloses a diesel engine tail gas cleaning device. The diesel engine tail gas cleaning device comprises a gaseous ammonia generation system, a pretreatment system and a catalytic reduction reaction system which are connected sequentially. The front end of the gaseous ammonia generation system is connected with a diesel engine tail gas exhaust outlet. An air-flowing type sprayer is adopted in the gaseous ammonia generation system for spraying a urea solution into very fine mist, and gaseous ammonia is generated under the action of high-temperature tail gas. The pretreatment system is used for retaining solid impurities and unburnt oil drops in the diesel engine tail gas. The solid impurities comprise solid particle matters and / or asphalt-like materials. The tail gas treated through the pretreatment system is subjected to react with the gaseous ammonia in the catalytic reduction reaction system, and cleaned gas is obtained. According the diesel engine tail gas cleaning device, the problem, that can not be solved through an existing tail gas cleaning device, that failure of a porous ceramic catalyst unit is caused after unburnt heavy oil micro-droplets, carbide particle matters, sulfate particle matters and even the very high-viscosity asphalt-like materials enter the porous ceramic catalyst unit is solved.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a diesel engine tail gas purification device. Background technique [0002] The exhaust gas emitted by the diesel engine contains gaseous and solid pollutants, and the gaseous pollutants are mainly NO X , SO 2 , CO, HC and sulfur-containing mixtures, etc.; the most important solid pollutant is carbonized particulate matter. In the prior art, the method for purifying the above-mentioned gaseous pollutants mainly adopts the selective catalytic reduction method to purify NO in the gaseous pollutants. X and CO; in this method, the reactants are gaseous ammonia NH 3 , the usual way to obtain gaseous ammonia is: to change the urea-water solution into a micro-droplet state through air spray or high-pressure spray and fully mix it with high-temperature tail gas, and the urea in the urea-water solution is rapidly heated to 160°C The above decomposes to produce ammonia...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is: how to solve the problem that cannot be solved by the existing exhaust gas treatment device, after the unburned heavy oil droplets, carbonized, sulfurized particles and even highly viscous asphalt-like substances enter the porous ceramic catalytic unit, Problems caused by the failure of porous ceramic catalytic units

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