CN202157847U - Construction machinery SCR post processor - Google Patents

Abstract

An SCR post-processor for engineering machinery, comprising a housing, in which an intake mixing chamber, a reactant chamber and an outlet mixing chamber are sequentially arranged; an inlet pipe is connected to the side of the inlet mixing chamber, and At least one exhaust pipe is connected, the reactant chamber is filled with a reactant carrier, and the reactant carrier is coated with a catalyst coating. The utility model has the characteristics of fast response speed, high reliability, high sensitivity and compact structure, and works together with the urea injection system without adding engine body parts and mufflers, which can efficiently meet the catalytic conversion efficiency of the SCR system and reduce mechanical noise requirements.

Description

Construction Machinery SCR Post Processor

technical field

The utility model relates to a diesel engine tail gas treatment device, in particular to an engineering machinery SCR post processor.

Background technique

Diesel engines have obvious advantages over gasoline engines in terms of power, economy and reliability, especially low CO ₂ emissions, and their use has gradually been extended to various types of vehicles. But the biggest problem with diesel engines is the serious emission of nitrogen oxides and particulates. As China's emission control regulations become more and more stringent, as well as the performance and oil quality of domestic diesel engines, internal purification measures alone are insufficient. Therefore, it is necessary to adopt an external after-treatment system to achieve emission targets.

SCR technology is an off-board post-treatment technology for vehicle diesel engines, which can effectively improve the emission of nitrogen oxides from diesel engines and is insensitive to the sulfur content of diesel. Since construction machinery works at low speed and high load for a long time, the temperature and airflow noise are not obvious, but because construction machinery has high requirements for layout, the SCR requirements for construction machinery should be as low as possible and radiation noise should be avoided as much as possible.

For construction machinery special SCR catalytic converters, it can be evaluated by the following indicators.

1. Installation height

Optimize muffler stage height and mixer height.

2. Radiation noise

Optimize the system plane and avoid large plane design.

3. Service life

Designed for the entire life of the vehicle.

Utility model content

The purpose of the utility model is to provide an engineering machinery SCR post-processor with good fluidity and moderate pressure loss.

The purpose of this utility model is achieved in this way: a construction machinery SCR post-processor, including a housing, in which an inlet mixing chamber, a reactant chamber and an outlet mixing chamber are sequentially arranged; the side of the inlet mixing chamber is connected There is an air inlet pipe, at least one exhaust pipe is connected to the side of the gas outlet mixing chamber, a reactant carrier is filled in the reactant chamber, and a catalyst coating is coated on the reactant carrier.

The reactant carrier is a cylindrical cordierite product, which is provided with a plurality of axially penetrating parallel channels, and the catalyst coating is coated on the inner surface of each channel.

The catalyst coating is a vanadium-titanium-tungsten mixture coating.

There are two exhaust pipes, and the two exhaust pipes are arranged side by side to form a double tailpipe.

The exhaust pipe is a heat exchanger pipe.

The SCR post processor of the utility model has the advantages of fast response, moderate pressure loss and high reliability through finite element analysis (FEA) and computational fluid dynamics (CFD) flow analysis demonstration.

Description of drawings

Fig. 1 is a three-dimensional structural schematic diagram of the SCR post-processor of the construction machinery of the present invention;

Fig. 2 is a schematic structural diagram of the front view of the construction machinery SCR post-processor of the utility model.

Detailed ways

Referring to Fig. 1 and Fig. 2, the construction machinery SCR post-processor of the present invention includes a housing 1, in which an air intake mixing chamber 2, a reactant chamber 3 and an air outlet mixing chamber 4 are sequentially arranged. The side of the intake mixing chamber is connected with an air inlet pipe 5, and the side of the outlet mixing chamber is connected with at least one exhaust pipe 6, and the reactant carrier 7 is filled in the reactant chamber, and the reactant carrier 7 is coated with Catalyst coating. The shell 1 is made of austenitic stainless steel, the reactant carrier 7 is a cylindrical cordierite product, and a plurality of axially penetrating parallel channels are arranged in it, and the catalyst coating is coated on the inner surface of each channel. The catalyst coating is a vanadium-titanium-tungsten mixture coating.

Exhaust pipe among the utility model can be designed as one or two, when adopting two exhaust pipes, two exhaust pipes are arranged side by side to form double tailpipe.

The exhaust pipe in the utility model can also be designed as a heat exchanger pipe to reclaim the heat in the tail gas.

The working principle of the SCR post-processor for construction machinery of the utility model is that the intake pipe 5 is connected with the exhaust pipe of the exhaust outlet of the engine, and the exhaust gas generated during the operation of the diesel engine is input to the post-SCR through the connecting pipe between the diesel engine and the SCR post-processor. In the processor, in the inlet mixing chamber 2, the exhaust gas and ammonia gas are uniformly mixed through the mutual turbulence of the perforated pipe and the mixing baffle, and then input into the reactant chamber 3, and the diesel engine is catalyzed by the reactant carrier 7 and the catalyst coating. Nitrogen oxides in the exhaust gas are converted into harmless nitrogen and water vapor, and then discharged into the atmosphere through the exhaust pipe 6, and at the same time complete the muffler effect, effectively reducing the noise level of the diesel engine. The utility model has the characteristics of fast response speed, high reliability, high sensitivity and compact structure, and works together with the urea injection system without adding engine body parts and mufflers, and satisfies the convenience of loading and the catalytic conversion efficiency of the SCR system and vehicle noise requirements.

The catalytic conversion efficiency of the engineering machinery SCR post-processor of the utility model is determined according to the amount of exhaust gas discharged from the engine, the highest can reach 90%, and the lowest can reach 60%.

Claims (4)

1. A construction machinery SCR post-processor, characterized in that: it comprises a housing, in which an intake mixing chamber, a reactant chamber and an outlet mixing chamber are sequentially arranged; the side of the intake mixing chamber is connected with an intake pipe, At least one exhaust pipe is connected to the side of the gas outlet mixing chamber, a reactant carrier is filled in the reactant chamber, and a catalyst coating is coated on the reactant carrier. 2. The engineering machinery SCR post-processor according to claim 1, characterized in that: the reactant carrier is a cylindrical cordierite product, in which a plurality of axially penetrating parallel passages are provided, and the catalyst A coating is applied to the inner surface of each channel. 3. The construction machinery SCR post-processor according to claim 1, characterized in that: there are two exhaust pipes, and the two exhaust pipes are arranged side by side to form a double tailpipe. 4. The construction machinery SCR post-processor according to claim 1 or 3, characterized in that: the exhaust pipe is a heat exchanger pipe. the

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