Device for quantitatively generating ammonia from solid urea

Abstract

The invention belongs to the technical field of denitration during a motor vehicle exhaust treatment process, and relates to a device for quantitatively generating ammonia from solid urea so as to reduce nitric oxides in motor vehicle exhaust. The device is composed of a solid urea storage tank, a solid urea quantitative lead-out device and a urea reaction cavity, wherein urea powder in the urea storage tank is accurately and quantitatively led out via the solid urea quantitative lead-out device, enters in an exhaust branch tube under the action of gravity, and is sprayed onto a urea catalyst carrier in the urea reaction cavity under the air injection function of the exhaust. The urea sprinkled on the surface of the catalyst carrier is rapidly reacted to generate ammonia in the presence of a catalyst, the generated ammonia is led out to an exhaust tube via an ammonia lead-out tube under the action of the exhaust flow, and enters into an SCR (selective catalytic reduction) reactor installed on the exhaust tube together with NOx in the exhaust, thus performing SCR reaction. Via the device, the disadvantages of the prior art in the field are solved to a certain extent; and the device has the advantages of low energy consumption, great efficiency, strong practicability, simple equipment, high safety, and the like.

Description

technical field [0001] The invention belongs to the technical field of denitrification in the treatment process of motor vehicle tail gas, and in particular relates to a device for quantitatively generating ammonia gas from solid urea to reduce nitrogen oxides in motor vehicle tail gas. Background technique [0002] In recent years, the rapid development of my country's automobile industry has made significant contributions to the national economy and social development. But at the same time, a series of problems such as traffic congestion, air pollution, and energy crisis have also emerged. Due to the massive use of buses and diesel trucks in big cities, the pollution is very serious. The annual NOx emissions in my country exceed 11 million tons, and there is an increasing trend. NOx in motor vehicle exhaust is a serious hazard to humans and the environment. Removing NOx in exhaust gas has become an urgent problem to be solved in the process of exhaust gas aftertreatment. ...

AI Technical Summary

Problems solved by technology

However, urea aqueous solution is easy to freeze and difficult to store at low temperature; and during the pyrolysis process of urea aqueous solution, most of the energy will be consumed in order to evaporate the water in urea

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