Thermal Decomposition System of Reductant in Selective Catalytic Reduction Device

Abstract

The invention relates to a reductant thermal decomposition system of a selective catalytic reduction device. The reductant pyrolysis system of the selective catalytic reduction device of the present invention includes: an elbow (10), which is arranged on the exhaust pipe at the front end of the reactor (Reactor) to allow the exhaust gas to flow in, and to discharge the inflow exhaust gas to the Reactor side; an inner pipe unit (20), which is arranged inside the elbow (10), so that a part of the exhaust gas flows in and discharged; a heating device (60), which is arranged on the inner pipe unit (20), heating the waste gas flowing into the inner pipe unit (20); and a nozzle (70), which is arranged on the inner pipe unit (20), and is arranged on the side of the heating device (60) based on the flow of the waste gas. On the rear end side, a reducing agent is injected into the inner pipe unit (20).

Description

technical field [0001] The present invention relates to a reductant pyrolysis system of a selective catalytic reduction device, and more specifically, relates to a system in which an inner pipe is arranged inside a main pipe, and when the exhaust gas flows into the inner pipe, the inflowing exhaust gas is heated toward the heated The reductant pyrolysis system of the exhaust gas injection reductant selective catalytic reduction device. Background technique [0002] In general, exhaust gas is generated when diesel engines, boilers, incinerators, etc. are used. Nitrogen oxides (NOx) are contained in the exhaust gas. In order to purify nitrogen oxides, a selective reduction catalytic reduction device (SCR: Selective Catalytic Reduction) is used. [0003] The selective reduction catalytic reduction device injects a reducing agent into the exhaust gas to reduce nitrogen oxides contained in the exhaust gas to nitrogen and water for purification. Urea is used as a reducing agent...

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Problems solved by technology

[0014] However, the ammonia gas injection method utilizing the reducing agent pyrolysis system requires a large number of additional components compared to the reducing agent direct injection method, and requires arranging many of the above-described components, which has the problem of occupying a large space.

[0015] In addition, conventionally known pyrolysis systems for reducing agents have the following problems: in order to transfer the reducing agent between the various components, the piping configuration is complicated, and the equipment cost increases.

[0016] In addition, conventionally known thermal decomposition systems for reducing agents have the following problems: additional energy (electric power, fuel, air pressure) and costs are required for driving the blower (Blower) and the heating device (Heating Device)

However, Patent Document 1 cannot control the flow rate of the exhaust gas flowing into the inner tube, so it cannot provide an appropriate mixing ratio. If the reducing agent is too large compared to the exhaust gas flow rate, there is a concern that the reducing agent will leak to the outside.

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