Static mixer for mixing urea aqueous solution and engine exhaust gas

Abstract

The present disclosure relates to a static mixer for mixing a urea solution and engine exhaust gas. The static mixer includes: an external tube including one end portion connected to an exhaust manifold of a diesel engine, the other end portion connected to an SCR (Selective Catalytic Reduction), and a part with which a urea solution injection adaptor is provided; an internal tube installed inside the external tube so as to have a constant gap between at least a part of an outer wall surface and an inner wall surface of the external tube; and a channel unit comprising a plurality of guiding channels provided inside the internal tube in a longitudinal direction, and having an inlet portion facing a lower end portion of the urea solution injector adaptor. The present disclosure may make the exhaust gas and the urea solution before passing through the SCR pass through the inlet portion and the plurality of guiding channels of the channel unit to form fine and even mixed gas, thereby largely decreasing an amount of nitride oxide (NOx) discharged to the air by improving a catalytic reduction reaction ratio in the SCR.

Description

[0001]This Application is a Section 371 National Stage Application of International Application No. PCT / KR2011 / 004979, filed Jul. 7, 2011 and published, not in English, as WO2012 / 005527 on Jan. 12, 2012.[0002]FIELD OF THE DISCLOSURE[0003]The present disclosure relates to a static mixer for mixing a urea solution and engine exhaust gas, and more particularly, to a static mixer for mixing a urea solution and engine exhaust gas capable of finely and evenly mixing exhaust gas discharged from an exhaust manifold of a diesel engine to an inlet portion of an SCR (Selective Catalytic Reduction) of an exhaust pipe and a urea solution supplied from a urea solution injector of the exhaust pipe to the inlet portion of the SCR in order to decrease an amount of exhaust gas generated during a combustion process of mixed gas of the diesel engine and accompanying nitrogen oxide (NOx) discharged to the atmosphere.BACKGROUND OF THE DISCLOSURE[0004]In general, a diesel engine injects fuel, such as dies...

AI Technical Summary

Benefits of technology

This patent provides a static mixer for mixing a urea solution and engine exhaust gas to decrease nitrogen oxide (NOx) emissions and improve the efficiency of the selective catalytic reduction (SCR) process. The mixer includes a channel unit with multiple guiding channels and an inlet portion surrounded by an external tube, which helps to finely and evenly mix the exhaust gas and urea solution before they pass through the SCR. The mixer also includes blades at the outlet side of the channel plates to achieve better mixing. The design improves the evaporation environment of the urea solution and reduces the amount of nitrogen oxide (NOx) discharged to the atmosphere, while also removing waste of the urea solution. Overall, this mixer helps to increase the efficiency of the SCR process and reduce harmful emissions.

Problems solved by technology

When the amount of air supplied to the combustion chamber is larger than that of the fuel supplied to the combustion chamber, output is greatly increased, but the air supplied to the combustion chamber the air and is harmful to the human body, and an amount of generation of nitrogen oxide (NOx) which is the cause of acid rain, photochemical smog phenomenon, and the like is increased.

However, since the mixer of the diesel engine in the related art has a structure in which the channel unit including the plurality of guiding channels is simply accommodated inside the exhaust pipe, there is a problem in that the exhaust gas discharged from an exhaust manifold of the engine to the mixer is not finely and evenly mixed well with the urea solution supplied from the urea solution injector, so that an amount of nitrogen oxide (NOx) discharged to the atmosphere is not largely decreased.

Further, in the mixer of the diesel engine in the related art, since the exhaust pipe accommodating the channel unit has a form of a single duct, when the urea solution is in direct contact with an inner wall surface of the exhaust pipe directly exposed to the air, the urea solution is not evaporated and flows down along the inner wall surface of the exhaust pipe, so that there is a problem in that the urea solution is not appropriately used for decreasing nitrogen oxide (NOx) and is directly discharged to the outside.

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