CN217783881U - Ethylene glycol sprays vacuum unit - Google Patents

Abstract

The utility model discloses an ethylene glycol injection vacuum unit, which comprises a first-stage ejector, a first-stage condenser, a second-stage ejector, a second-stage condenser, a third-stage ejector and a third-stage condenser which are connected in sequence, wherein the ejector at each stage has the same structure, the first-stage ejector comprises a diffuser, the air inlet end of the diffuser is connected with a nozzle chamber, and a nozzle assembly is inserted in the nozzle chamber; the nozzle assembly comprises a heating sleeve, a heating cavity is arranged in the heating sleeve, a flange is coaxially arranged at the outer side end of the heating sleeve, two air inlet channels and two air outlet channels which are communicated with the heating cavity are respectively arranged in the flange, an air guide pipe is further arranged in the heating cavity, one end of the air guide pipe is communicated with one air inlet channel, the other end of the air guide pipe extends to the inner side end of the heating cavity, and a nozzle is sealed and extends into the end part of the heating sleeve to be flush with the end part of the heating sleeve after penetrating through the flange. Through above-mentioned mode, the easy liquefaction and then lead to the unstable condition of vacuum pump operation when the ethylene glycol steam in effectively having solved current vacuum ejector pump gets into the nozzle chamber via the nozzle blowout.

Description

Ethylene glycol sprays vacuum unit

Technical Field

The utility model relates to a jet vacuum unit, especially a glycol jet vacuum unit.

Background

The internal components of the jet vacuum pump mainly comprise a Laval nozzle and a diffuser, and the working process of the jet vacuum pump can be divided into three stages: adiabatic expansion stage, mixing stage, compression stage.

In the adiabatic expansion stage, after working steam passes through the convergent-divergent nozzle, pressure energy is converted into velocity energy, the velocity energy enters the diffuser at a very high speed, and meanwhile, the pressure of the working steam is reduced at the outlet of the nozzle to form vacuum to suck an air-extracted body;

in the mixing stage, the gas to be extracted enters a diffuser, steam and the gas to be extracted collide and mix in the diffuser for energy exchange, and the steam and the gas to be extracted are mixed at the throat part of the diffuser, so that the two gases reach the same speed;

in the compression stage, after the mixed gas passes through the throat part of the diffuser, the speed of the mixed gas is reduced, the pressure is further increased, the outlet of the diffuser reaches the atmospheric pressure or the inlet pressure of the next-stage ejector, and the pumped gas is discharged.

Ethylene glycol is widely used in vacuum-pumping devices as a vacuum-pumping medium which can be recycled. The entrance temperature of the ethylene glycol steam is generally between 200 and 207 ℃ during vacuum pumping, when the ethylene glycol steam is sprayed out from a nozzle or a diffuser, the volume of the gas can be rapidly expanded, the temperature of the steam is rapidly reduced, and when the temperature of the ethylene glycol steam is rapidly reduced to be lower than the boiling point (197.3 ℃), the ethylene glycol can be liquefied, so that the dryness of the ethylene glycol steam is reduced, and the vacuum pumping capacity and the vacuum stability of the jet vacuum pump are further influenced. In the existing mode, a heat insulation structure is additionally arranged outside a diffuser of a vacuum pump so as to reduce the liquefaction degree of ethylene glycol. However, the problem of this structure is that the glycol vapor has two expansion processes in the jet pump, one occurs in the nozzle chamber and one occurs in the diffuser, wherein the most severe expansion process is mainly from the process of the glycol vapor sprayed from the convergent-divergent nozzle entering the nozzle chamber, and the glycol vapor passing through the nozzle in the process is liquefied in the nozzle if the glycol vapor cannot be maintained at an effective temperature, and then even if a heat preservation measure is provided outside the diffuser, the liquefied glycol will not be vaporized rapidly, which greatly affects the stability and the vacuum-pumping effect of the jet vacuum pump.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned insufficiency, the utility model aims at providing an ethylene glycol sprays vacuum unit to solve the condition that ethylene glycol liquefies easily in the nozzle chamber of vacuum pump.

In order to achieve the above purpose, the technical scheme of the utility model is that:

the first-stage ejector comprises a diffuser, the diffuser is provided with an exhaust end and an air inlet end, the air inlet end is connected with a nozzle chamber, and a nozzle assembly is inserted in the nozzle chamber; the nozzle assembly comprises a heating sleeve inserted into a nozzle chamber, the axial direction of the inner side end of the heating sleeve extends to the end close to the air inlet, a heating chamber is arranged in the heating sleeve, a flange plate is coaxially arranged at the outer side end of the heating sleeve, two air inlet channels and air outlet channels communicated with the heating chamber are respectively arranged in the flange plate, an axially extending air guide pipe is further arranged in the heating chamber, one end of the air guide pipe is communicated with one of the air inlet channels, the other end of the air guide pipe extends to the inner side end of the heating chamber, and one nozzle is sealed and extends into the end parallel and level with the end of the heating sleeve after penetrating through the flange plate.

In this scheme, establish the heating jacket through the outside cover of nozzle and realized heating up to the rapid ethylene glycol steam that passes through in the nozzle, and then guarantee that ethylene glycol steam can not appear a large amount of liquefaction phenomena because of the quick reduction of temperature after getting into the nozzle chamber, and then maintained the stability of vacuum jet pump operation. It should be noted that, the purpose of preventing the liquefaction of the ethylene glycol vapor in advance is achieved by heating the ethylene glycol vapor at the nozzle stage, and compared with the traditional mode of heating at the diffuser part, the scheme has the effect of obviously reducing the liquefaction of the ethylene glycol. In addition, it should be noted that in the scheme, the heating medium can enter the inner side end of the heating cavity through the air guide pipe connected with one air inlet channel, so that the heating medium is uniformly dispersed in the heating cavity, the uniformity of the heating temperature of the heating sleeve is ensured, the heat quantity of the glycol during the process of passing through the nozzle is more uniform, the state fluctuation amplitude of the glycol in the nozzle is reduced, and the running stability of the equipment is ensured.

Preferably, the caliber of the air inlet channel is smaller than the inner diameter of the air guide tube. The heating medium is displayed to accelerate in the air guide pipe in a mode of reducing the aperture, then the heating medium can be ejected out of the air guide pipe at a high speed, the air guide pipe ejected out at a high speed can better realize dispersion of the heating medium in the heating cavity, and uniform distribution of the heating medium in the heating cavity is realized.

Preferably, the diffuser is externally sleeved with a heat insulation sleeve, a gap is reserved between the heat insulation sleeve and the diffuser to form a heat insulation cavity, and the heat insulation sleeve is provided with an air inlet pipe and an air outlet pipe which are communicated with the heat insulation cavity.

Preferably, the air outlet pipes are arranged at two ends of the heat insulation sleeve, and the air inlet pipes are arranged in the middle of the heat insulation sleeve. Through setting up the intake pipe in the centre of insulation cover, the outlet duct setting makes heating medium's stroke shorten generally at the both ends of insulation cover, and then has reduced heating medium because the stroke is too long and the big problem of both ends temperature difference that leads to, and then has effectively maintained the temperature stability of ethylene glycol steam in the diffuser.

Preferably, the thermal insulation sleeve extends to the outside of the nozzle chamber. The steam entering the nozzle chamber is subjected to a heat-insulating treatment by extending the heat-insulating jacket. After ethylene glycol steam is sprayed and is acutely expanded from the inflation, the indoor negative pressure that produces of nozzle and then with the gas suction in the vacuum chamber, along with the gas admission in the vacuum chamber and mix with ethylene glycol, certain change can take place for the ethylene glycol temperature, and the temperature of the mist that then can effectively stabilize and mix in the nozzle chamber through the heat preservation of insulation cover is handled, guarantees that the ethylene glycol can not take place the liquefaction, and then keeps the steady operation of jet pump.

Preferably, the first-stage condenser is also provided with a first-stage parallel ejector.

Through above-mentioned mode, the easy liquefaction and then lead to the unstable condition of vacuum pump operation when the ethylene glycol steam in effectively having solved current vacuum ejector pump gets into the nozzle chamber via the nozzle blowout.

Drawings

Fig. 1 is a schematic structural diagram of the present invention;

FIG. 2 is a left side view of FIG. 1;

FIG. 3 is a bottom view of FIG. 1;

FIG. 4 is a schematic diagram of a one-stage ejector configuration.

Reference numerals are as follows: 100. the first-stage ejector 110, the diffuser 111, the exhaust end 112, the air inlet end 120, the nozzle chamber 130, the nozzle assembly 131, the heating sleeve 132, the heating chamber 133, the flange 134, the air inlet passage 135, the air outlet passage 136, the air guide pipe 137, the nozzle 140, the heat insulating sleeve 141, the air inlet pipe 142, the air outlet pipe 150, the heat insulating chamber 200, the first-stage condenser 300, the second-stage ejector 400, the second-stage condenser 500, the third-stage ejector 600, the third-stage condenser 700 and the first-stage parallel ejector.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1 to 4, the glycol injection vacuum unit includes a first-stage ejector 100, a first-stage condenser 200, a second-stage ejector 300, a second-stage condenser 400, a third-stage ejector 500, and a third-stage condenser 600, which are connected in sequence. In order to improve the operation stability of the vacuum unit, the first-stage ejector 100, the second-stage ejector 300 and the third-stage ejector 500 are the same in structure capable of reducing the liquefaction degree of the ethylene glycol steam during vacuum pumping. Specifically, the one-stage injector 100 includes a diffuser 110 having a waist-drum-shaped structure with a reduced middle and two enlarged ends, and the diffuser 110 has an exhaust end 111 and an intake end 112. The exhaust end 111 is connected to the condenser, and the intake end 112 is connected to the nozzle chamber 120. At the same time, a nozzle assembly 130 capable of raising the temperature of the supplied ethylene glycol vapor is installed in the nozzle chamber. Specifically, the nozzle assembly includes a heating jacket 131 disposed coaxially with the diffuser and having an inner end extending proximate to the inlet end, and a heating chamber 132 disposed within the heating jacket and extending axially along the heating jacket, wherein a heating medium is introduced to heat the heating jacket to heat the glycol vapor passing through the nozzle. It should be noted that, in order to make the heating jacket maintain a uniform temperature during the heating process, as shown in fig. 4, a flange 133 is coaxially welded to the outer end of the heating jacket, and two air inlet passages 134 extending along the radial direction of the flange and two air outlet passages 135 extending along the radial direction of the flange are respectively provided in the flange. Both the inlet and outlet air passages are in communication with the heating chamber 132. An air duct 136 is provided in the heating chamber and extends axially along the heating jacket, one end of the air duct being connected to one of the air inlet passages and the other end extending to the inside end of the heating chamber. In addition, as shown in FIG. 4, the nozzle assembly includes a nozzle 137 which extends axially through the flange and seals to an end flush with the inside end of the heating jacket. Through this structure, the heating jacket realizes the steady heating to the nozzle for the rapid heating up that the ethylene glycol steam that passes through the nozzle can be stable, prevents to get into the nozzle room after because rapid expansion and the liquefaction of cooling down. It should be noted that, in this embodiment, the heating medium enters and exits the heating chamber through the conduits respectively connected to the air inlet passage and the air outlet passage. It should be noted that the heating medium in this embodiment is typically high temperature steam of 280 ℃. + -. 5 ℃.

Preferably, the inner diameter of the air duct is smaller than the caliber of the air inlet channel. So that the heating medium in the air duct can be sprayed out at an accelerated speed.

Preferably, in order to further reduce the probability of liquefaction of ethylene glycol, a thermal insulation sleeve 140 is sleeved outside the diffuser, a gap is reserved between the thermal insulation sleeve and the diffuser to form a thermal insulation cavity 150 with the diffuser, and when the vacuum pumping is performed, the heating medium enters and exits the thermal insulation cavity through an air inlet pipe 141 and an air outlet pipe 142 arranged on the thermal insulation sleeve, so that the thermal insulation treatment is performed on the diffuser.

Preferably, the outlet duct is provided at both ends of the insulating jacket and the inlet duct is provided at a middle portion of the insulating jacket.

Preferably, in order to further reduce the liquefaction rate of the ethylene glycol vapor in the nozzle chamber, the heat-insulating jacket extends to the outside of the nozzle chamber and encloses the nozzle chamber therein.

In addition, in order to further improve the vacuum pumping effect, a primary parallel ejector 700 is further installed on the primary condenser.

Claims (6)

1. The utility model provides a glycol sprays vacuum unit which characterized in that: the single-stage ejector comprises a diffuser, wherein the diffuser is provided with an exhaust end and an air inlet end, the air inlet end is connected with a nozzle chamber, and a nozzle assembly is inserted in the nozzle chamber; the nozzle assembly comprises a heating sleeve inserted into a nozzle chamber, the axial direction of the inner side end of the heating sleeve extends to the end close to the air inlet, a heating chamber is arranged in the heating sleeve, a flange plate is coaxially arranged at the outer side end of the heating sleeve, two air inlet channels and air outlet channels communicated with the heating chamber are respectively arranged in the flange plate, an axially extending air guide pipe is further arranged in the heating chamber, one end of the air guide pipe is communicated with one of the air inlet channels, the other end of the air guide pipe extends to the inner side end of the heating chamber, and one nozzle is sealed and extends into the end parallel and level with the end of the heating sleeve after penetrating through the flange plate.

2. The ethylene glycol injection vacuum unit as set forth in claim 1, wherein: the caliber of the air inlet channel is smaller than the inner diameter of the air guide tube.

3. The ethylene glycol injection vacuum unit as set forth in claim 1 or 2, wherein: the diffuser is externally sleeved with a heat insulation sleeve, a gap is reserved between the heat insulation sleeve and the diffuser to form a heat insulation cavity, and the heat insulation sleeve is provided with an air inlet pipe and an air outlet pipe which are communicated with the heat insulation cavity.

4. The ethylene glycol injection vacuum unit of claim 3, wherein: the air outlet pipes are arranged at two ends of the heat insulation sleeve, and the air inlet pipes are arranged in the middle of the heat insulation sleeve.

5. The ethylene glycol injection vacuum unit of claim 4, wherein: the heat-insulating sleeve extends to the outside of the nozzle chamber.

6. The ethylene glycol injection vacuum unit as set forth in claim 1, wherein: and the primary condenser is also provided with a primary parallel ejector.

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