CN211500759U - Urea injection vaporizer of SCR diesel engine catalytic cleaner - Google Patents

Abstract

The utility model discloses a urea injection vaporizer of SCR diesel engine catalytic converter, the outside at the vaporizer inner tube is provided with a vaporizer outer tube, form a urea vaporizer between vaporizer inner tube and the vaporizer outer tube, be provided with 2-6 urea liquid input holes on the vaporizer outer tube of urea vaporizer front end uniformly, urea spray tube is being connected to the urea liquid input hole, the other end and the urea union coupling of urea spray tube, be provided with 2-20 urea steam input holes around the circumference uniformly on the vaporizer inner tube of vaporization intermediate layer rear end, be provided with the metal foam board in the exit of vaporizer inner tube. After urea is sprayed into the vaporization interlayer through the urea spray pipe, the urea is instantly gasified into urea steam in the vaporization interlayer heated by high-temperature waste gas, the urea steam is sprayed into the inner pipe of the vaporizer from the urea steam hole and is discharged to the catalytic purification muffler along with the waste gas to participate in the catalytic purification process of the waste gas, and the problem of crystallization caused by the fact that spray of the spray nozzles can not be consistent for a long time is solved.

Description

Urea injection vaporizer of SCR diesel engine catalytic cleaner

Technical Field

The utility model relates to a urea injection vaporizer of SCR diesel engine catalytic converter belongs to automobile engine tail gas aftertreatment technical field.

Background

The catalytic reduction method of the catalytic cleaner of the diesel engine is also called as SCR (selective catalytic reduction) method, the technology can accelerate the reduction of NOx in tail gas and simultaneously effectively inhibit oxidation reaction, can enable the NOx conversion rate to reach more than 90% on the premise of not reducing the efficiency of the engine, and has the advantages of better fuel economy, high sulfur resistance and the like. The catalytic purifier is a key component for the exhaust aftertreatment of the diesel engine for the vehicle, is an important component for ensuring that the exhaust emission of the vehicle meets the requirements of national environmental protection regulations, and has the function of carrying out oxidation and reduction reactions on the exhaust containing harmful gases under the action of a catalyst in the catalytic converter to convert the exhaust into harmless gases to be discharged into the air. In the process, ammonia gas is required to participate in the conversion of carbon monoxide, hydrocarbon, oxynitride and lead compounds in the tail gas into water and harmless gas, the participation form of the ammonia is converted from urea, urea solution is sprayed and atomized through a urea nozzle, atomized urea mist forms ultrafine uniform particles and is quickly converted into ammonia gas under a proper temperature condition to participate in the catalytic purification process of the tail gas, the key part in the process is the urea nozzle, the precision requirement of the urea nozzle is very high and cannot meet the precision requirement, and urea crystals are very easily formed in the urea spray to block the nozzle. At present, the precision part can only meet the precision requirement of products of German Boshi company, German mainland company and American Delfu company, so that the foreign high-precision nozzle forms monopoly situation on the market of the catalytic cleaner of the engine in China, and the market price of the imported high-precision nozzle is extremely high and far exceeds the reasonable cost range. The present invention relates to a urea vaporization injection device, and more particularly to a urea vaporization injection device, which comprises a urea vaporization injection device, a urea vaporization. Therefore, it is an advancement of the catalytic purification technology to provide a device that replaces a high-precision urea nozzle in a catalytic converter of a diesel engine. After search, no technical disclosure has been found for vaporizing urea outside the catalytic converter except for the urea nozzle.

Disclosure of Invention

An object of the utility model is to provide a urea injection vaporizer of SCR diesel engine catalytic converter for urea can vaporize into even particle outside catalytic converter, gets into catalytic converter with the urea gas form again, overcomes the not enough of the needs accurate nozzle that traditional urea vaporization exists, and easily forms the not enough of urea crystallization.

In order to achieve the above object, the present invention adopts the following specific technical measures. A urea injection vaporizer of a catalytic silencing purifier of an SCR diesel engine comprises a tubular vaporizer inner tube, the front end of the tubular vaporizer inner tube is connected with an exhaust port of the engine, the rear end of the tubular vaporizer inner tube is connected with a catalytic purification silencer, a vaporizer outer tube is arranged outside the vaporizer inner tube, a urea vaporizing chamber is formed between the vaporizer inner tube and the vaporizer outer tube, 2-6 urea liquid input holes are uniformly arranged on the vaporizer outer tube at the front end of the urea vaporizing chamber, the urea liquid input holes are connected with a urea spray tube, the other end of the urea spray tube is connected with the urea tube, 2-20 urea vapor input holes are uniformly arranged on the vaporizer inner tube at the rear end of a vaporizing interlayer around the circumference, and a metal foam plate is arranged at an outlet of the vaporizer inner tube.

The utility model adopting the measures, after urea is sprayed into the vaporization interlayer through the urea spray pipe, the urea is instantly gasified into urea steam in the vaporization interlayer heated by high-temperature waste gas, and is sprayed into the vaporizer inner pipe from the urea steam hole and is discharged to the catalytic purification silencer along with the waste gas, thereby participating in the catalytic purification process of the waste gas, and avoiding the defect that the atomized particles are not uniform in size and are easy to be produced when the urea spray nozzle is used for spraying atomized urea liquid traditionally, the traditional spray nozzle has inconsistent requirements on the precision of the spray hole, so that the atomization is easy to be inconsistent, the coarse urea atomized particles can not be gasified in time to form water molecules to escape, thus urea crystallization is easy to block the air vent of the catalytic carrier, the utility model has no need of high requirements on the precision of the urea spray nozzle, and the gasified urea gas quickly enters the vaporizer inner pipe from the urea steam hole arranged on the vaporizer inner pipe under the state of, and then the waste gas enters the catalytic cleaner together, and passes through the exhaust hole of the catalytic unit in the optimal state, so that the problem that the traditional complex mixing structural part can reach the optimal mixed gas is avoided, the cost is saved, the crystallization problem caused by the fact that the spray of the nozzle can not be consistent for a long time is solved, meanwhile, the high-precision urea nozzle is removed, and the dependence on the foreign high-precision urea nozzle in the catalytic purification treatment process for a long time is solved.

Drawings

FIG. 1 is a schematic view of the structure of the inner and outer vaporization tubes of the present invention;

FIG. 2 is a schematic structural view of the present invention;

fig. 3 is a schematic structural diagram of the connection between the urea delivery pipe and the bluing tank of the present invention.

The numbering of the above figures illustrates:

the device comprises a vaporizer inner tube 1, a vaporizer outer tube 2, a urea vaporization chamber 3, a urea spray tube 4, a multi-way joint 5, a urea liquid conveying tube 6, a urea liquid input hole 7, a urea steam input hole 8, a metal foam plate 9, a bluing tank 10, a metering pump 11, a catalytic purifier 12, an exhaust gas inlet 13, an exhaust gas outlet 14, a primary urea liquid conveying main pipe 15 and a secondary urea liquid conveying main pipe 16.

The present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

Detailed Description

As shown in the attached drawings, the utility model mainly comprises an inner tube 1 and an outer tube 2 of the carburetor. The inner tube 1 of the carburetor is cylindrical, and has different diameters and different lengths when being assembled on engines with different powers, the waste gas inlet end is the front end and the waste gas outlet end is the rear end according to the flowing direction of waste gas, the front end of the inner tube 1 of the carburetor is connected with the exhaust port of the engine, and the waste gas discharged by the engine firstly enters the inner tube 1 of the carburetor from the inner tube 1 of the carburetor. An outer vaporizer tube 2 is arranged outside the inner vaporizer tube 1 in a welding mode, the diameter of the outer vaporizer tube 2 is 10-100 mm larger than that of the inner vaporizer tube 1, so that a vaporizing interlayer is formed between the inner vaporizer tube 1 and the outer vaporizer tube 2, the space of the interlayer is a urea vaporizing chamber 3, and urea is vaporized into urea steam in the urea vaporizing chamber 3. The volume of the urea vaporization chamber 3 is provided with a urea injection metering pump according to the power of the engine, the metering pump is changed by calibrating the metering of injected urea liquid according to the quantity of NOx, and the volume of the urea vaporization chamber 3 is set according to the power of the engine according to the proportion. The front and back welding parts of the outer tube 2 and the inner tube 1 of the carburetor are both provided with a circumferential outer tube protrusion 2-1, 2-6 urea liquid input holes 7 are uniformly arranged on the front outer tube protuberance 2-1, one end of a urea spray tube 4 is fixedly connected with the urea input holes 7 in a screw-tight mode, the other end of the urea spray tube is connected with a urea liquid conveying tube 6, the diameter of the urea spray tube 4 is 1-6 mm, urea liquid is sprayed into a urea vaporization chamber 3 through the urea spray tube 4, because the temperature of the exhaust gas discharged by the engine during working is very high and reaches above 550 ℃ of the maximum temperature, therefore, the temperature of the tube wall of the inner tube 1 of the carburetor connected with the exhaust outlet of the engine is high, so that the temperature of the urea vaporization chamber 3 is high, and after the urea liquid is sprayed into the urea vaporization chamber 3 from the urea spray tube 4, the urea liquid is instantly vaporized into urea steam under the action of high temperature. 2-20 urea steam input holes 8 are uniformly arranged on the inner tube 1 of the vaporizer at the rear end of the urea vaporizing chamber 3 around the circumference, the aperture of each urea steam input hole 8 is 2-6 mm, and the arrangement of the urea steam input holes 8 meets the requirement that the speed and the amount of the urea steam input into the inner tube 1 of the vaporizer and the speed and the amount of the urea liquid sprayed into the urea vaporizing chamber 3 reach balance. A metal foam plate 9 is fixed in the exhaust gas outlet 14 of the carburetor inner tube 1, and the metal foam plate 9 serves to make the exhaust gas uniformly enter the catalytic converter 12.

The utility model discloses an operating condition is like this: first, the utility model discloses the front end of vaporizer inner tube 1 passes through flange joint with the engine gas vent, and the rear end passes through the flange to be connected with catalytic converter 12, and engine exhaust's waste gas is followed the utility model discloses an exhaust gas inlet 13 gets into vaporizer inner tube 1, during 14 discharges entering catalytic converter 12 from exhaust outlet. The urea liquid is output from a bluing tank 10 through a primary urea liquid conveying main pipe 15, distributed to the urea liquid through a metering pump 11 and then conveyed to a multi-way joint 5 through a secondary urea liquid conveying main pipe 16, wherein the multi-way joint 5 refers to a 2-6-way joint, the urea liquid is uniformly distributed to a urea liquid conveying pipe 6 through the multi-way joint 5 and then sprayed into a urea vaporization chamber 3 through a urea spray pipe 4, the urea liquid is instantly vaporized into urea vapor in the urea vaporization chamber 3, the urea vapor flows to the rear end of the urea vaporization chamber and enters a vaporizer inner pipe 1 through a urea vapor input hole 8, and is rapidly mixed with exhaust gas discharged by an engine in the vaporizer inner pipe 1, and the urea vapor is discharged to a catalytic purifier 12 through an exhaust gas outlet 14 to participate in catalytic purification work of the exhaust gas. In the process, the urea liquid is quickly vaporized into urea steam in the high-temperature urea vaporization chamber 3, the particle size of the urea steam is uniform, and the phenomenon of non-uniform particle size does not exist, so that the defect that the size of the atomized particles inevitably generated by spraying through a traditional nozzle is not uniform is overcome.

Claims (8)

1. A urea injection vaporizer of a catalytic purifier of an SCR diesel engine comprises a tubular vaporizer inner tube (1) with the front end connected with an exhaust port of the engine and the rear end connected with a catalytic purification muffler (12), and is characterized in that a vaporizer outer tube (2) is arranged outside the vaporizer inner tube (1), a urea vaporization chamber (3) is formed between the vaporizer inner tube (1) and the vaporizer outer tube (2), circumferential outer tube protrusions (2-1) are arranged at the front and rear welding positions of the vaporizer outer tube (2) and the vaporizer inner tube (1), 2-6 urea liquid input holes (7) are uniformly arranged on the front outer tube protrusions (2-1), the urea liquid input holes (7) are connected with a urea spray tube (4), the other end of the urea spray tube (4) is connected with the urea liquid injection tube (6), and 2-20 urea evaporation liquid conveying tubes are uniformly arranged on the vaporizer inner tube (1) at the rear end of the urea vaporization chamber (3) around the circumference A metal foam plate (9) is arranged at the exhaust gas outlet (14) of the inner tube (1) of the carburetor at the steam inlet hole (8).

2. The urea injection vaporizer of the catalytic converter of the SCR diesel engine according to claim 1, wherein the diameter of the outer vaporizer tube (2) is 10-100 mm larger than the diameter of the inner vaporizer tube (1), so that a vaporizing layer is formed between the inner vaporizer tube (1) and the outer vaporizer tube (2), and the space of the vaporizing layer is a urea vaporizing chamber (3).

3. The urea injection vaporizer of a catalytic converter of an SCR diesel engine according to claim 1 or 2, characterized in that the volume of the urea vaporization chamber (3) is provided with a urea injection metering pump according to the power level of the engine, the metering pump is changed by calibrating the amount of injected urea liquid according to the amount of NOx, and the volume of the urea vaporization chamber (3) is set according to the power level of the engine according to the ratio.

4. The urea injection vaporizer of the catalytic converter of the SCR diesel engine according to claim 1, wherein one end of the urea spray pipe (4) is fixedly connected with the urea liquid input hole (7) in a screw-tight manner, the other end is connected with the urea liquid delivery pipe (6), and the pipe diameter of the urea spray pipe (4) is 1-6 mm.

5. The urea injection vaporizer of a catalytic converter of an SCR diesel engine according to claim 1, characterized in that the aperture of the urea vapor inlet hole (8) is 2-6 mm.

6. The urea injection carburetor of a catalytic converter of an SCR diesel engine according to claim 1, characterized in that a metal foam plate (9) is fixed at an exhaust gas outlet (14) of the carburetor inner tube (1).

7. The urea injection vaporizer of the catalytic converter of the SCR diesel engine according to claim 1, wherein the urea liquid feeding pipe (6) is connected with a secondary urea liquid feeding main pipe (16) through a multi-way joint (5), the secondary urea liquid feeding main pipe (16) is connected with a primary urea liquid feeding main pipe (15) through a metering pump (11), and the primary urea liquid feeding main pipe (15) is connected with the bluing tank (10).

8. Urea injection carburetor according to claim 7, characterized in that the multi-way connection (5) is a 2-6 connection.

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