CN201874646U

CN201874646U - Direct injection metering jetting device

Info

Publication number: CN201874646U
Application number: CN2010202761733U
Authority: CN
Inventors: 郝庆军
Original assignee: Suzhou Powergreen Emission Solution System Co Ltd
Current assignee: Suzhou Powergreen Emission Solution System Co Ltd
Priority date: 2010-07-30
Filing date: 2010-07-30
Publication date: 2011-06-22
Anticipated expiration: 2020-07-30

Abstract

The utility model relates to a direction injection metering jetting device, comprising a metering vale, an air pipeline and a jetting pipeline, wherein the metering valve comprises a metering valve nozzle; the direct injection metering jetting device further comprises an air atomizing nozzle, the metering valve nozzle is arranged in the air atomizing nozzle, the air pipeline and the jetting pipeline are further arranged in the air atomizing nozzle; the air atomizing nozzle comprises a base, a liquid cap and an air cap; the air pipeline and the jetting pipeline are all arranged in the base, the liquid cap and the air cap. The direction injection metering jetting device is skill in design and good in atomizing effect, which is capable of reducing back pressure and producing cooling effect so as to guarantee that the nozzle is hard to burnout.

Description

Direct spray type metered injection device

Technical field

The utility model relates to a kind of exhaust gas from diesel vehicle post-processing purifying system, relates in particular to a kind of direct spray type metered injection device.

Background technique

Along with improving constantly of vehicular emission standard, the vehicle tai-gas clean-up system is the day by day extremely concern of vehicle manufacturers also, and various technology paths are also ripe gradually.

Existing known, by selective catalytic reduction technology (SCR) is to reduce a kind of main mode of diesel-oil vehicle NOx discharging, being about to reducing agent (aqueous solution of urea) is pumped in the metering valve by pumping element, again through the quantitative injection atomizing, process complex physico-chemical in gas exhaust piping, main harmful gas NOx in the waste gas is changed into the nitrogen G﹠W discharge, reach the purpose of tail gas clean-up.Wherein, the broken and atomizing of the conveying of aqueous solution of urea, drop is to the NH of SCR carrier inlet ₃Distribution has a significant impact, and is the key factor that influences SCR system catalytic reaction efficient.

In the prior art, aqueous solution of urea metered injection device is divided into two kinds in gas and no gas, there is the gas jet system mainly to rely on pump that reducing agent is pumped into the metering valve inlet, by the accurate metered injection of metering valve in mixing chamber, high velocity air carries out the reducing agent that ejects primary atomization and is blown into the nozzle place, carry out atomized spray in the nozzle ejection process once more in gas exhaust piping, in the SCR carrier, carry out selective reaction after the pyrolysis in outlet pipe of the reducing agent of secondary-atomizing, the hydrolysis.This have the gas jet system that himself advantage is arranged, promptly in mixing chamber, carry out gas-liquid mixed, and by being installed in the nozzle secondary injection atomizing in the outlet pipe, atomizing effect is good, and can cool off nozzle by high velocity air, prevent that nozzle from being burnt out under the outlet pipe hot environment, but this structure also has its shortcoming, structure is complicated, the pressure reduction of metering valve entrance and exit must reach the requirement that certain value could satisfy emitted dose, that is: require the pressure in the nozzle upstream pipeline to be greater than the interior pressure of outlet pipe, and the pressure of metering valve upstream is greater than the mixed downstream chamber, the pressure that injection pipe and nozzle entrance etc. are located.In addition, in mixing chamber, the jet pressure of reducing agent must be higher than the pressure of high velocity air, otherwise reducing agent can't spray, this is called " big back pressure " in industry, under the environment of big back pressure in order to reach enough flows, the pressure of metering valve inlet also must increase just thereupon can keep enough pressure reduction, this designing requirement to pipeline is higher, because pressure is bigger, has increased sealing difficulty simultaneously, and pipeline has the risk of explosion, influence its working life, the outlet pressure of pumping element increases thereupon in addition, and power consumption increases.

Another structure is exactly an airless injection system, the most typical in industry with the DENOXTRONIC2.2 system of BOSCH company, be that metering valve is set directly on the outlet pipe, by direct metered injection of metering valve and atomizing, though this system is simple in structure, though can cool off metering valve by return line, but because nozzle ejection position cooling effect is poor, still ablated easily, simultaneously owing to can only lean on the self-pressure liquid atomizing, atomizing effect is limited, the ammonia concentration distributing homogeneity is had a significant impact, if will reach atomizing effect preferably, the inlet pressure of metering valve will reach more than the 9bar, and this gives pump, pipeline, the design of sealing configuration etc. etc. all brings difficulty.

The model utility content

The purpose of this utility model is to have overcome above-mentioned shortcoming of the prior art, and a kind of direct spray type metered injection device is provided, and the utility model design is ingenious, can reduce back pressure, atomizing effect is good, and can produce cooling effect, guarantees to demonstrate,prove not easy burn-out of nozzle.

To achieve these goals, the utility model provides a kind of direct spray type metered injection device, comprise metering valve, air pipe line and injection line, described metering valve comprises the metering valve nozzle, described direct spray type metered injection device also comprises air atomizer spray nozzle, described metering valve nozzle is arranged on the inside of described air atomizer spray nozzle, and described air pipe line and described injection line are arranged on the inside of described air atomizer spray nozzle.

Preferably, described air atomizer spray nozzle comprises base, liquid cap and air cap, described air cap is arranged on the neutral position of described base and described liquid cap, described metering valve front portion is arranged on the inside of described base and described liquid cap, and all air pipe lines and injection line all are arranged on described base, described liquid cap and air cap inside.

Preferably, described base side wall is provided with air flow inlet, and described base forms first breathing space on the surface that is connected with described liquid cap, and described first breathing space is the annular recessed portion structure, and described first breathing space and described air flow inlet are communicated with

Preferably, described liquid cap forms second breathing space on the surface that is connected with described base, and described second breathing space is the annular recessed portion structure.

More preferably, be provided with pad between described base and the described liquid cap, evenly at interval several holes be set on the described pad, the hole on the described pad is communicated with described first breathing space and described second breathing space.

Preferably, described liquid cap is inner evenly to be provided with some airflow holes at interval, and described airflow hole is communicated with described air flow inlet and described injection line by first breathing space and second breathing space.

Preferably, neutral position, described liquid cap end forms spray-hole, and described metering valve nozzle is installed in the described spray-hole.

More preferably, described air cap intermediate portion forms jet exit, and described liquid cap spray-hole extends in the described jet exit, and forms airflow clearance with jet exit.

Preferably, form air flow chamber between described liquid cap and the described air cap, described air flow chamber is communicated with described air pipe line and described injection line.

Preferably, described air atomizer spray nozzle also comprises hold-doun nut, and described hold-doun nut connects described liquid cap and described air cap.

The utlity model has following beneficial effect: design ingeniously, atomizing effect is good, can reduce back pressure, and air pipe line is arranged in the air atomizer spray nozzle can produce better cooling effect.

Description of drawings:

Fig. 1 is the utility model direct spray type metered injection device plan view

Fig. 2 is the utility model direct spray type metered injection device installation diagram

Fig. 3 is the utility model direct spray type metered injection device sectional view

Fig. 4 is the sectional view of base in the utility model direct spray type metered injection device

Fig. 5 is the plan view of base in the utility model direct spray type metered injection device

Fig. 6 is the stereogram of liquid cap in the utility model direct spray type metered injection device

Fig. 7 is the plan view of liquid cap in the utility model direct spray type metered injection device

Fig. 8 is the plan view of installing on the liquid cap in the utility model direct spray type metered injection device behind the pad

Fig. 9 is an A portion enlarged view among Fig. 3

Embodiment:

In order more to be expressly understood technology contents of the present utility model, describe in detail especially exemplified by following examples.

As Fig. 1, Fig. 2 and shown in Figure 3, the utility model direct spray type metered injection device 1 comprises metering valve 2 and air atomizer spray nozzle 10, described air atomizer spray nozzle 10 comprises base 3, liquid cap 4 and air cap 5, described base 3 is arranged on the top of described liquid cap 4, and base 3 and liquid cap 4 central positions form recess, the front portion of described metering valve 1 is installed in the recess, and described base 3 is tightly connected by seal ring 11 with described metering valve 2.

As Fig. 4, shown in Figure 5, base 3 is a circular ring, its middle position forms through hole 34, its annulus sidewall is provided with air flow inlet extension part 31, be provided with air flow inlet 32 in the extension part, described base 3 bottoms are provided with first breathing space 33, and described first breathing space 33 is to be formed by toroidal cavity, air flow inlet 32 on base 3 sidewalls is a blind hole structure, and and described first breathing space, 33 connections.

As Fig. 3, Fig. 6, shown in Figure 7, liquid cap 4 comprises first step portion 41, second step portion 42 and body 43, described first step portion 41 is installed in the through hole 34 of described base, and form cavity 44 in first step portion 41 and body 43, described through hole 34 and cavity 44 form the recess that metering valve is installed; Form second breathing spaces 45 in the described second step portion 42, described second breathing space 45 be the ring groove structure, with base 3 installation processes in, first breathing space 33 and second breathing space 45 form the passages cooperations.

Preferably; between described base 3 and described liquid cap 4, pad 6 is set,, eight holes 61 is set at interval evenly on the described pad 6 as Fig. 2, shown in Figure 8; described eight holes 61 are communicated with described first breathing space 33 and described second breathing space 45, and described pad also plays the seal protection function.

As Fig. 3, Fig. 6 and shown in Figure 7,4 airflow holes 46 evenly are set in described second breathing space 45 at interval, described airflow hole 46 is a through hole, the body 43 that runs through described liquid cap 4, the 3rd stepped part 47 is formed at described body 43 bottoms, described airflow hole 46 is arranged on described the 3rd stepped part 47 with respect to the other end of second breathing space 45, and described liquid cap body 43 sidewalls 48 are worm structure, are used to install described hold-doun nut 7.

The lower end of described liquid cap 4 is provided with spray-hole 8, and described metering valve nozzle 21 is arranged in the described spray-hole 8.

As Fig. 3, shown in Figure 8, described air cap 5 is installed in the downside of described liquid cap 4 by hold-doun nut 7, described air cap 5 upper end portions form a hook step laterally, described hold-doun nut 7 lower ends inwardly form a hook step, described hold-doun nut 7 is connected described liquid cap 4 and described air cap 5 by the cooperation of hook step and the worm structure of liquid cap body sidewall 48, and forms air flow chamber 9 between described liquid cap 4 and described air cap 5; Described air cap 5 middle positions form jet exit 11, and the spray-hole 8 in the described liquid cap 4 extends in the described jet exit 11, and form airflow clearance 12 with described jet exit 11 inwalls, and airflow clearance 12 can provide airflow.

By above-mentioned setting, described air flow inlet 31, first breathing space 33, second breathing space 45, airflow hole 46, air flow chamber 9, airflow clearance 12 and described jet exit 11 form air pipe line; Described metering valve nozzle 21, injection pipe 8 and described jet exit 11 form injection line; All air pipe lines and injection line all are arranged on the inside of described air atomizer spray nozzle 10, are not subjected to outside Effect of Hyperthermic Environment substantially.

The utility model direct spray type metered injection device control procedure is as follows:

As Fig. 3, shown in Figure 9, when preparing the injection reduction agent, the air pipe line of pressurized air in air atomizer spray nozzle 10 at first, be that compressed air stream enters first breathing space 33 by air flow inlet 31, the compressed air stream diffusion of expanding in first breathing space 33, eight holes 61 on pad 6 enter in second breathing space 45 again, the compressed air stream diffusion of expanding once more in second breathing space 45, arrive jet exit 11 through airflow hole 46, air flow chamber 9, airflow clearance 12, finish air purge; The while reducing agent is pumped the element (not shown) and is pumped in the metering valve 2, when pressure reaches predetermined value, measurement control unit (not shown) in the after-treatment system receives injection signal, the beginning metered injection, reducing agent is through injection line, and promptly spray-hole 8 in the liquid cap 4 and the jet exit 11 in the air cap 5 spray, pressurized air in jet exit 11 in reducing agent and the air pipe line carries out mixing jetting, atomizes in course of injection.

Use in the cleaning system of the present utility model, because reducing agent is in jet exit 11 is directly injected to the outlet pipe (not shown), as long as guarantee enough pressure reduction (being the pressure reduction in metering valve 2 upstreams and the outlet pipe), just can guarantee enough flows, therefore when metering valve back pressure occurs and hangs down, the metering valve upstream need not too big pressure, and whole cleaning system also just can be designed to low pressure line, is difficult for leakage, explosion, upstream pump power consumption and advantage such as reduces; Can cool off metering valve spout and metering valve nozzle by air-flow simultaneously, be unlikely to be burnt, and avoid water-cooled pipeline complexity, problems such as leakage.

To sum up, the utility model direct spray type metered injection device design is ingenious, simple in structure, reduce back pressure, and atomizing and good cooling results have avoided the interior waste gas of metering valve and outlet pipe directly to contact, and prolong its working life.

In this specification, the utility model is described with reference to its specific preferred embodiment.But, still can make various modifications and conversion obviously and do not deviate from spirit and scope of the present utility model, therefore, specification and accompanying drawing are regarded in an illustrative, rather than a restrictive.

Claims

1. direct spray type metered injection device, comprise metering valve, air pipe line and injection line, described metering valve comprises the metering valve nozzle, it is characterized in that: described direct spray type metered injection device also comprises air atomizer spray nozzle, described metering valve nozzle is arranged on the inside of described air atomizer spray nozzle, and described air pipe line and described injection line are arranged on the inside of described air atomizer spray nozzle.

2. direct spray type metered injection device according to claim 1, it is characterized in that: described air atomizer spray nozzle comprises base, liquid cap and air cap, described air cap is arranged on the neutral position of described base and described liquid cap, described metering valve front portion is arranged on the inside of described base and described liquid cap, and all air pipe lines and injection line all are arranged on described base, described liquid cap and air cap inside.

3. direct spray type metered injection device according to claim 2, it is characterized in that: described base side wall is provided with air flow inlet, described base forms first breathing space on the surface that is connected with described liquid cap, described first breathing space is the annular recessed portion structure, and described first breathing space and described air flow inlet are communicated with.

4. direct spray type metered injection device according to claim 2 is characterized in that: described liquid cap forms second breathing space on the surface that is connected with described base, and described second breathing space is the annular recessed portion structure.

5. according to claim 3 or the described direct spray type metered injection of claim 4 device, it is characterized in that: be provided with pad between described base and the described liquid cap, evenly at interval several holes is set on the described pad, the hole on the described pad is communicated with described first breathing space and described second breathing space.

6. direct spray type metered injection device according to claim 5 is characterized in that: described liquid cap is inner evenly to be provided with some airflow holes at interval, and described airflow hole is communicated with described air flow inlet and described injection line by first breathing space and second breathing space.

7. according to claim 2 or the described direct spray type metered injection of claim 6 device, it is characterized in that: neutral position, described liquid cap end forms spray-hole, and described metering valve nozzle is installed in the described spray-hole.

8. direct spray type metered injection device according to claim 7 is characterized in that: described air cap intermediate portion forms jet exit, and described liquid cap spray-hole extends in the described jet exit, and forms airflow clearance with jet exit.

9. direct spray type metered injection device according to claim 2 is characterized in that: form air flow chamber between described liquid cap and the described air cap, described air flow chamber is communicated with described air pipe line and described injection line.

10. direct spray type metered injection device according to claim 2, it is characterized in that: described air atomizer spray nozzle also comprises hold-doun nut, described hold-doun nut connects described liquid cap and described air cap.