CN113982928A - Screw vacuum pump and liquid ring vacuum pump series-parallel combined system - Google Patents
Screw vacuum pump and liquid ring vacuum pump series-parallel combined system Download PDFInfo
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- CN113982928A CN113982928A CN202111274959.0A CN202111274959A CN113982928A CN 113982928 A CN113982928 A CN 113982928A CN 202111274959 A CN202111274959 A CN 202111274959A CN 113982928 A CN113982928 A CN 113982928A
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- 239000007788 liquid Substances 0.000 title claims abstract description 149
- 238000002156 mixing Methods 0.000 claims abstract description 31
- 238000000034 method Methods 0.000 claims description 19
- 239000000498 cooling water Substances 0.000 claims description 15
- 239000000110 cooling liquid Substances 0.000 claims description 9
- 238000001816 cooling Methods 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 239000007789 gas Substances 0.000 description 51
- 238000005086 pumping Methods 0.000 description 12
- 239000000203 mixture Substances 0.000 description 8
- 230000007797 corrosion Effects 0.000 description 5
- 238000005260 corrosion Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 238000000605 extraction Methods 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 230000001815 facial effect Effects 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000013618 particulate matter Substances 0.000 description 1
- 238000011197 physicochemical method Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000011345 viscous material Substances 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
- F04C23/005—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of dissimilar working principle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C19/00—Rotary-piston pumps with fluid ring or the like, specially adapted for elastic fluids
- F04C19/004—Details concerning the operating liquid, e.g. nature, separation, cooling, cleaning, control of the supply
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C25/00—Adaptations of pumps for special use of pumps for elastic fluids
- F04C25/02—Adaptations of pumps for special use of pumps for elastic fluids for producing high vacuum
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/02—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids specially adapted for several pumps connected in series or in parallel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
- F04C28/28—Safety arrangements; Monitoring
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
- F04C29/12—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
Abstract
The invention discloses a series-parallel combined system of a screw vacuum pump and a liquid ring vacuum pump, which comprises the screw vacuum pump, the liquid ring vacuum pump, a liquid ring pump air inlet one-way valve, a screw pump air inlet one-way valve, an air inlet two-position three-way pneumatic valve, a screw pump air inlet shutoff valve, a screw pump exhaust one-way valve, a tail gas mixing ejector, a vapor-liquid separator, a circulating pump and a pressure transmitter, wherein the screw pump air inlet one-way valve is connected with the screw pump air inlet one-way valve; when the real-time pressure of the pressure transmitter is greater than a preset value, the two-position air inlet three-way pneumatic valve is switched to a first air inlet to be communicated with an air outlet of the three-position air inlet three-way pneumatic valve, a second air inlet of the three-position air inlet three-way pneumatic valve is closed to the air outlet of the three-position air inlet three-way pneumatic valve, and the liquid ring vacuum pump and the screw vacuum pump are connected in parallel at the moment; when the real-time pressure value of the pressure transmitter is smaller than or equal to the preset value, the air inlet two-position three-way pneumatic valve is switched to the second air inlet to be communicated with the air outlet of the pressure transmitter, the first air inlet of the pressure transmitter is closed to the air outlet of the pressure transmitter, the liquid ring vacuum pump is connected with the screw vacuum pump in series, and the screw vacuum pump and the liquid ring vacuum pump can improve the running stability of the vacuum unit system.
Description
Technical Field
The invention relates to the technical field of vacuum pumps, in particular to a series-parallel combination system of a screw vacuum pump and a liquid ring vacuum pump.
Background
The vacuum pump refers to a device or equipment for obtaining vacuum by pumping a pumped container by using a mechanical, physical, chemical or physicochemical method. The vacuum pump performance of different structures is also different, and in industrial application, then need satisfy the demand of different air exhaust ability and the requirement of working vacuum degree, and user's demand is hardly satisfied to single vacuum pump usually, consequently needs a plurality of vacuum pumps to constitute vacuum unit system and realizes.
The traditional vacuum unit system adopts a plurality of roots vacuum pumps to be equipped with a backing pump, and the backing pump can be a liquid ring vacuum pump, or an oil type rotary vane pump, or a screw vacuum pump, or a slide valve vacuum pump. But basically a single type of backing pump is selected in combination with a roots vacuum pump to form a vacuum pumping set system. However, for different backing pumps, the medium pumped by the liquid ring pump can be a process medium containing dust, viscous substances, corrosive gases, inflammable and explosive and the like, and the pumping amount range is very wide and ranges from 20m3/h-20000m3However, the vacuum degree and the air suction capacity of the liquid ring pump are completely affected by the temperature of the circulating liquid, even at normal temperature, the vacuum degree of the liquid ring pump can only reach 3500Pa, and in order to obtain higher vacuum degree, one or more roots vacuum pumps need to be arranged at the air inlet of the liquid ring pump. However, the roots vacuum pump has its drawbacks, for example, when the pumping capacity of the liquid ring pump is affected by the temperature of the circulating liquid, the vacuum degree of the inlet thereof is reduced, and the operation pressure difference of the roots vacuum pump is increased, thereby causing the exhaust temperature of the roots vacuum pump to be increased and the current to be increased. At the not good application environment of cooling water operating mode, especially under summer high temperature, the circulating liquid temperature that liquid ring pump was always can appear is too high, leads to roots vacuum pump to transship, and overheated operation, and then make the vacuum unit appear frequently tripping operation or roots vacuum pump overheated card phenomenon of dying.
If the preceding stage adopts a screw vacuum pump, the screw pump can reach higher vacuum degree, and the air extraction capacity is not directly related to the ambient temperature and the cooling water temperature. However, the air extraction capacity of the screw vacuum pump is generally 100-2000m due to the structural characteristics3And therefore, for some vacuum systems needing larger air extraction capacity, a plurality of roots vacuum pumps are required to be arranged to realize the gradual increase of the air extraction capacity, and the purpose of the method is slightly different from that of a liquid ring pump which is provided with a plurality of roots pumps to gradually increase the vacuum degree of the system. However, the screw vacuum pump has a small air exhaust capacity, and is suitable for the applied air exhaust capacity, so that the compression ratio between the roots pumps is often too high, and the roots vacuum pump is overheated during operation. Simultaneous screwThe rod vacuum pump can directly exhaust air, has high gas compression density, and cannot reduce the compression heat of gas through circulating liquid like a liquid ring pump. Therefore, the temperature of the exhaust port of the screw vacuum pump is very high, so that carbonization and polymerization of hydrocarbon gas occur when part of organic compounds are pumped, and the hydrocarbon gas adheres to the screw rotor, thereby causing screw pump failure.
Although the upper surface of the overflowing element of the screw vacuum pump is made of corrosion-resistant materials, the problem of corrosion still cannot be thoroughly solved, because the plating layer falls off from the raw materials due to different expansion coefficients in a high-temperature environment, if expensive corrosion-resistant materials are directly adopted, the processing is difficult to realize, and the cost of equipment is also overhigh. And most importantly, even if expensive corrosion-resistant materials are adopted, corrosive gas penetrates through a gear box of the screw vacuum pump to corrode the gear, and the corrosion of the bearing still cannot be solved.
Therefore, a brand new combination is required to be adopted in the conventional vacuum unit system to solve the defects and hidden dangers of the existing combination of a single roots vacuum pump-liquid ring vacuum pump or a roots vacuum pump-screw vacuum pump so as to realize more reliable operation.
Disclosure of Invention
The invention aims to provide a series-parallel combined system of a screw vacuum pump and a liquid ring vacuum pump so as to improve the running stability of a vacuum unit system.
In order to achieve the purpose, the invention provides a series-parallel combined system of a screw vacuum pump and a liquid ring vacuum pump, which comprises the screw vacuum pump, the liquid ring vacuum pump, a liquid ring pump air inlet one-way valve, a screw pump air inlet one-way valve, an air inlet two-position three-way pneumatic valve, a screw pump air inlet shutoff valve, a screw pump exhaust one-way valve, a tail gas mixing ejector, a vapor-liquid separator, a circulating pump and a pressure transmitter, wherein the screw pump air inlet one-way valve is connected with the screw pump air inlet one-way valve;
the inlet end of the screw pump inlet shutoff valve is communicated with a process gas inlet through a first pipeline, the outlet end of the screw pump inlet shutoff valve is communicated with the inlet end of the screw vacuum pump through a second pipeline, the outlet end of the screw vacuum pump is communicated with the inlet end of the tail gas mixing ejector through a third pipeline, the second pipeline is provided with a screw pump inlet one-way valve, and the third pipeline is provided with a screw pump exhaust one-way valve;
the inlet end of the liquid ring vacuum pump is communicated with a process gas inlet through a fourth pipeline, an air inlet two-position three-way pneumatic valve and an air inlet one-way valve of the liquid ring pump are sequentially arranged from the air inlet end to the air outlet end of the fourth pipeline, the outlet end of the liquid ring vacuum pump is communicated with the inlet end of the tail gas mixing ejector through a fifth pipeline, the first air inlet end of the air inlet two-position three-way pneumatic valve is connected with the process gas inlet, the second air inlet end of the air inlet two-position three-way pneumatic valve is communicated with a third pipeline, and the connection point of the air inlet two-position three-way pneumatic valve and the third pipeline is positioned between the outlet end of the screw vacuum pump and the screw pump exhaust one-way valve;
the gas-liquid inlet end of the gas-liquid separator is communicated with the gas-liquid outlet end of the tail gas mixing ejector, the cooling liquid outlet end of the gas-liquid separator, the cooling liquid inlet end of the screw vacuum pump, the cooling liquid outlet end of the screw vacuum pump and the liquid inlet end of the liquid ring vacuum pump are communicated through a cooling pipeline, and a circulating pump is arranged on the cooling pipeline;
the first pipeline is communicated with a fourth pipeline, and the pressure transmitter is arranged on the fourth pipeline;
when the real-time pressure of the pressure transmitter is greater than a preset value, the two-position air inlet three-way pneumatic valve is switched to a first air inlet communicated with an air outlet of the two-position air inlet three-way pneumatic valve, a second air inlet of the two-position air inlet three-way pneumatic valve is closed to the air outlet of the two-position air inlet three-way pneumatic valve, and at the moment, the liquid ring vacuum pump is connected with the screw vacuum pump in parallel; when the real-time pressure value of the pressure transmitter is smaller than or equal to the preset value, the two-position air inlet three-way pneumatic valve is switched to the second air inlet to be communicated with the air outlet, the first air inlet is closed to the air outlet, and the liquid ring vacuum pump is connected with the screw vacuum pump in series.
Based on the above, when the real-time pressure of the pressure transmitter is greater than the preset value, the liquid ring vacuum pump and the screw vacuum pump simultaneously perform parallel air suction on the process main pipe to achieve the maximum air suction capacity, the second air inlet of the air inlet two-position three-way pneumatic valve is closed, the back pressure in the third pipeline is higher than the spring reverse force of the screw pump exhaust one-way valve, so that the screw pump exhaust one-way valve is jacked open, and the exhaust of the screw vacuum pump passes through the screw pump exhaust one-way valve. Meanwhile, the gas-liquid mixture of the liquid ring vacuum pump in operation directly enters the tail gas mixing ejector, the pressure of the gas-liquid mixture discharged from the outlet end of the liquid ring vacuum pump is high, the gas-liquid mixture enters the tail gas mixing ejector and is finally discharged into the gas-liquid separator, and the working principle of the tail gas mixing ejector is that power is converted into pressure through the Venturi effect, so that the gas-liquid mixture discharged from the liquid ring vacuum pump is weakened after passing through the tail gas mixing ejector and can be more effectively subjected to steam-water separation after entering the gas-liquid separator.
And the inlet end of the tail gas mixing ejector is directly connected to the exhaust port of the screw vacuum pump, so that the exhaust pressure of the screw vacuum pump can be reduced, the pressure difference between the air inlet end and the exhaust end of the screw vacuum pump is reduced, and the temperature of the exhaust end of the screw vacuum pump is reduced.
Because of the negative pressure that has of tail gas mixing ejector sunction inlet to can effectually take screw vacuum pump's liquid out, solved the air current vortex that screw vacuum pump formed in the exhaust port department promptly completely, also can reduce the difficult exhaust dust particulate matter's in the screw vacuum pump quantity by a wide margin simultaneously, more importantly, screw vacuum pump's exhaust pressure is in slightly negative pressure, the positive pressure gear box of the screw vacuum pump who adopts nitrogen protection this moment just can thoroughly stop the possibility that process gas cluster goes into, and then effectively protected screw vacuum pump, avoid screw vacuum pump to be corroded.
Along with the continuation of evacuation, when the real-time pressure value of pressure transmitter is less than or equal to the setting value, when the air exhaust ability of liquid ring vacuum pump approached its ultimate vacuum that can reach along with the system this moment, its air exhaust ability descends by a wide margin to cavitation phenomenon can take place probably, can lead to obvious vibrations, noise phenomenon. Meanwhile, as the vacuum degree is continuously improved, the liquid ring vacuum pump is quite possible to have no pumping capacity any more, but rather, the liquid ring vacuum pump plays a role in blocking, and part of gas and circulating liquid steam in the liquid ring vacuum pump are pumped back into the screw vacuum pump, so that serious accident potential is caused.
The two tee bend pneumatic valve gears that admit air this moment change, and the first inlet end of two tee bend pneumatic valves that admit air is closed, and the second inlet end is opened, and in the gas that screw vacuum pump combustion gas directly got into liquid ring vacuum pump promptly, liquid ring vacuum pump and screw vacuum pump formed the series connection mode this moment.
Under the higher vacuum environment, the front-mounted roots pump begins to play the role of pressurization, the advantage of parallel operation of the backing pump (liquid ring vacuum pump + screw vacuum pump) is different, at the moment, the screw vacuum pump independently realizes higher vacuum degree, the pressure reduction of the exhaust port of the front-mounted roots vacuum pump is ensured, and therefore the pressure difference of the roots vacuum pump is reduced.
After the two-position three-way pneumatic valve for air inlet is switched, the gas discharged by the screw vacuum pump mainly flows to the inlet end of the liquid ring vacuum pump, and the pressure of the exhaust end of the screw vacuum pump is greatly reduced to form larger negative pressure, so that the exhaust one-way valve of the screw pump is automatically closed, the gas does not enter a subsequent tail gas mixing ejector, and an original gas flow channel is automatically closed.
The exhaust gas flow of the screw vacuum pump enters the liquid ring vacuum pump, and is exhausted after being washed. It is therefore more advantageous to protect the gear box at the exhaust end of the screw vacuum pump whenever the exhaust pressure of the screw vacuum pump does not need to be above one atmosphere, thus making the screw vacuum pump more advantageous for pumping corrosive, viscous process media.
In the above technical solution, the present invention may be further modified as follows.
Preferably, the gas-liquid separator is internally provided with a heat exchanger.
Preferably, the gas-liquid separator is provided with a cooling water inlet and a cooling water outlet, the cooling water inlet is communicated with the liquid inlet end of the heat exchanger, and the cooling water outlet is communicated with the liquid discharge end of the heat exchanger.
Preferably, the vapor-liquid separator is provided with a temperature transmitter.
Preferably, the vapor-liquid separator is provided with a liquid level transmitter.
Preferably, the tail gas mixing injector is a water injector.
Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.
Drawings
In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below.
FIG. 1 is a schematic structural diagram of a series-parallel combination system of a screw vacuum pump and a liquid ring vacuum pump according to an embodiment of the present invention;
in the drawings, there is shown in the drawings,
the system comprises a screw vacuum pump 10, a liquid ring vacuum pump 11, a liquid ring pump air inlet one-way valve 12, a screw pump air inlet one-way valve 13, an air inlet two-position three-way pneumatic valve 14, a screw pump air inlet shutoff valve 15, a screw pump exhaust one-way valve 16, a tail gas mixing ejector 17, a vapor-liquid separator 18, a circulating pump 19, a pressure transmitter 20, a temperature transmitter 21 and a liquid level transmitter 22;
a first pipeline 31, a second pipeline 32, a third pipeline 33, a fourth pipeline 34, a fifth pipeline 35, and a cooling pipeline 36.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
Referring to fig. 1, the present embodiment provides a series-parallel combination system of a screw and a liquid ring vacuum pump 11, which includes a screw vacuum pump 10, a liquid ring vacuum pump 11, a liquid ring pump air inlet check valve 12, a screw pump air inlet check valve 13, an air inlet two-position three-way pneumatic valve 14, a screw pump air inlet shutoff valve 15, a screw pump exhaust check valve 16, a tail gas mixing ejector 17, a vapor-liquid separator 18, a circulating pump 19, and a pressure transmitter 20.
The inlet end of the screw pump inlet shutoff valve 15 is communicated with a process gas inlet through a first pipeline 31, the outlet end of the screw pump inlet shutoff valve 15 is communicated with the inlet of the screw vacuum pump 10 through a second pipeline 32, the outlet end of the screw vacuum pump 10 is communicated with the inlet end of the tail gas mixing ejector 17 through a third pipeline 33, the second pipeline 32 is provided with a screw pump inlet one-way valve 13, and the third pipeline 33 is provided with a screw pump exhaust one-way valve 16;
the inlet end of the liquid ring vacuum pump 11 is communicated with a process gas inlet through a fourth pipeline 34, an air inlet two-position three-way pneumatic valve 14 and a liquid ring pump air inlet one-way valve 12 are sequentially arranged from the air inlet end to the air outlet end of the fourth pipeline 34, the outlet end of the liquid ring vacuum pump 11 is communicated with the inlet end of the tail gas mixing ejector 17 through a fifth pipeline 35, the first air inlet end of the air inlet two-position three-way pneumatic valve 14 is connected with the process gas inlet, the second air inlet end of the air inlet two-position three-way pneumatic valve 14 is communicated with a third pipeline 33, and the connection point of the air inlet two-position three-way pneumatic valve 14 and the third pipeline 33 is positioned between the outlet end of the screw vacuum pump 10 and the screw pump exhaust one-way valve;
the gas-liquid inlet end of the gas-liquid separator 18 is communicated with the gas-liquid outlet end of the tail gas mixing ejector, the cooling liquid outlet end of the gas-liquid separator 18, the cooling liquid inlet end of the screw vacuum pump 10, the cooling liquid outlet end of the screw vacuum pump 10 and the liquid inlet end of the liquid ring vacuum pump 11 are communicated through a cooling pipeline 36, and a circulating pump 19 is arranged on the cooling pipeline 36;
the first pipeline is communicated with a fourth pipeline 34, and the pressure transmitter 20 is arranged on the fourth pipeline 34;
when the real-time pressure of the pressure transmitter 20 is greater than a preset value, the two-position air inlet three-way pneumatic valve 14 is switched to a first air inlet communicated with an air outlet thereof, a second air inlet is closed with the air outlet thereof, and at the moment, the liquid ring vacuum pump 11 is connected with the screw vacuum pump 10 in parallel; when the real-time pressure value of the pressure transmitter 20 is less than or equal to the preset value, the two-position air inlet three-way pneumatic valve 14 is switched to the second air inlet to be communicated with the air outlet thereof, the first air inlet is closed to the air outlet thereof, and the liquid ring vacuum pump 11 is connected with the screw vacuum pump 10 in series at the moment.
Based on the above, when the real-time pressure of the pressure transmitter 20 is greater than the preset value, it is indicated that the air pumping capacity of the liquid ring vacuum pump 11 is still within the optimal efficiency range at this time, the liquid ring vacuum pump 11 and the screw vacuum pump 10 simultaneously perform parallel air suction on the process main pipe to achieve the maximum air pumping capacity, the second air inlet of the air inlet two-position three-way pneumatic valve 17 is closed, so the back pressure in the third pipeline 33 is higher than the spring reverse force of the screw pump exhaust one-way valve 16, so that the screw pump exhaust one-way valve 16 is pushed open, and the exhaust of the screw vacuum pump 10 passes through the screw pump exhaust one-way valve 16. Meanwhile, the gas-liquid mixture of the liquid ring vacuum pump 11 directly enters the tail gas mixing ejector 17, the pressure of the gas-liquid mixture discharged from the outlet end of the liquid ring vacuum pump 11 is high, the gas-liquid mixture enters the tail gas mixing ejector 17 and is finally discharged into the gas-liquid separator 18, and the tail gas mixing ejector 17 adopts the working principle that power is converted into pressure through the Venturi effect, so that the gas-liquid mixture discharged from the liquid ring vacuum pump 11 is weakened after passing through the tail gas mixing ejector 17 and can be more effectively subjected to gas-water separation after entering the gas-liquid separator 18.
And the inlet end of the tail gas mixing ejector 17 is directly connected to the exhaust port of the screw vacuum pump 10, so that the exhaust pressure of the screw vacuum pump 10 is reduced, the pressure difference between the air inlet end and the exhaust end of the screw vacuum pump 10 is reduced, and the temperature of the exhaust end of the screw vacuum pump 10 is reduced.
Because the suction inlet of the tail gas mixing ejector 17 is provided with negative pressure (the negative pressure is generated by liquid discharge and ejection of the liquid ring vacuum pump 11), the liquid of the screw vacuum pump 10 can be effectively taken out, namely, the problem of airflow vortex formed at the exhaust outlet of the screw vacuum pump 10 is completely solved, and meanwhile, the amount of dust particles which are difficult to exhaust in the screw vacuum pump 10 can be greatly reduced, more importantly, the exhaust pressure of the screw vacuum pump 10 is slightly negative, the positive pressure gear box of the screw vacuum pump 10 protected by nitrogen can thoroughly avoid the possibility of the process gas entering in series, so that the screw vacuum pump 10 is effectively protected, and the screw vacuum pump 10 is prevented from being corroded.
With the continuation of vacuum pumping, when the real-time pressure value of the pressure transmitter 20 is less than or equal to the set value, the air pumping capacity of the liquid ring vacuum pump 11 is greatly reduced as the system approaches the limit vacuum that the system can reach, and cavitation may occur, which may result in obvious vibration and noise. Meanwhile, as the vacuum degree is continuously increased, the liquid ring vacuum pump 10 is likely to have no pumping capacity any more, but rather has a blocking effect, and a part of gas and circulating liquid steam in the liquid ring vacuum pump 10 is pumped back into the screw vacuum pump 10, thereby causing serious accident potential.
At this time, the gear of the air inlet two-position three-way pneumatic valve 14 is changed, the first air inlet end of the air inlet two-position three-way pneumatic valve 14 is closed, the second air inlet end is opened, namely, the gas exhausted by the screw vacuum pump 10 directly enters the liquid ring vacuum pump 11, and at this time, the liquid ring vacuum pump 11 and the screw vacuum pump 10 form a series mode.
Under a high vacuum environment, the front-mounted roots pump starts to play a role in pressurization, the advantage of parallel operation of the backing pump (the liquid ring vacuum pump 11+ the screw vacuum pump 10) is not in existence, at the moment, the screw vacuum pump 10 independently realizes higher vacuum degree, the pressure reduction of the exhaust port of the front roots vacuum pump is ensured, and therefore the pressure difference of the roots vacuum pump is reduced.
After the two-position three-way air-operated valve 14 for air intake is switched, the gas exhausted by the screw vacuum pump 10 mainly flows to the inlet end of the liquid ring vacuum pump 11, and the pressure at the exhaust end of the screw vacuum pump 11 is greatly reduced to form a large negative pressure, at the moment, the exhaust one-way valve 16 of the screw pump is automatically closed, so that the gas does not enter the subsequent tail gas mixing ejector 17, and the original gas flow channel is automatically closed.
The exhaust gas flow of the screw vacuum pump 10 enters the liquid ring vacuum pump 11, is similarly washed and then is exhausted. It is therefore more advantageous to protect the gear box at the exhaust end of the screw vacuum pump 10 whenever the exhaust pressure of the screw vacuum pump 10 does not need to be above one atmosphere, thus making the screw vacuum pump 10 more advantageous for pumping corrosive, viscous process media.
Meanwhile, the total pressure difference of the screw vacuum pump 10 is reduced, the inlet pressure of the screw vacuum pump 10 is further reduced, and the use of a front roots vacuum pump is more effective.
In this application, it is to be explained that: the real-time pressure value of the pressure transmitter 20 is a pressure determination value that is linked to the temperature of the circulating cooling water.
In this application, vapour and liquid separator 18 embeds has the heat exchanger, vapour and liquid separator 18 has cooling water inlet and cooling water outlet, the feed liquor end intercommunication of cooling water inlet and heat exchanger, the flowing back end intercommunication of cooling water outlet and heat exchanger sets up the separation effect that the heat exchanger can provide vapour and liquid separator 18.
In this application, vapour and liquid separator 18 facial make-up is equipped with temperature transmitter 21 and liquid level transmitter 22, can observe the temperature of vapour and liquid separator 18 in real time through temperature transmitter 21, can observe the liquid height in vapour and liquid separator 18 in real time through liquid level transmitter 22.
In the present embodiment, the exhaust gas mixing injector 17 is a water injector.
In conclusion, the screw vacuum pump and liquid ring vacuum pump series-parallel combined system provided by the embodiment can adjust the series-parallel state of the screw vacuum pump and the liquid ring vacuum pump according to the real-time pressure of the pressure transmitter, finally reach the optimal running state, and improve the running stability and the service life of the vacuum unit system.
Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims. The techniques, shapes, and configurations not described in detail in the present invention are all known techniques.
Claims (6)
1. A series-parallel combination system of a screw vacuum pump and a liquid ring vacuum pump is characterized by comprising a screw vacuum pump (10), a liquid ring vacuum pump (11), a liquid ring pump air inlet one-way valve (12), a screw pump air inlet one-way valve (13), an air inlet two-position three-way pneumatic valve (14), a screw pump air inlet shutoff valve (15), a screw pump exhaust one-way valve (16), a tail gas mixing ejector (17), a gas-liquid separator (18), a circulating pump (19) and a pressure transmitter (20);
the inlet end of the screw pump inlet shutoff valve (15) is communicated with a process gas inlet through a first pipeline (31), the outlet end of the screw pump inlet shutoff valve (15) is communicated with the inlet end of the screw vacuum pump (10) through a second pipeline (32), the outlet end of the screw vacuum pump (10) is communicated with the inlet end of the tail gas mixing ejector (17) through a third pipeline (33), the screw pump inlet one-way valve (13) is arranged on the second pipeline (32), and the screw pump exhaust one-way valve (16) is arranged on the third pipeline (33);
the inlet end of the liquid ring vacuum pump (11) is communicated with a process gas inlet through a fourth pipeline (34), an air inlet two-position three-way pneumatic valve (14) and a liquid ring pump air inlet one-way valve (12) are sequentially arranged from the air inlet end to the air outlet end of the fourth pipeline (34), the outlet end of the liquid ring vacuum pump (11) is communicated with the inlet end of a tail gas mixing ejector (17) through a fifth pipeline (35), the first air inlet end of the air inlet two-position three-way pneumatic valve (14) is connected with the process gas inlet, the second air inlet end of the air inlet two-position three-way pneumatic valve (14) is communicated with a third pipeline (33), and the connection point of the air inlet two-position three-way pneumatic valve (14) and the third pipeline (33) is located between the outlet end of the screw vacuum pump (10) and the screw pump exhaust one-way valve (16);
the gas-liquid inlet end of the gas-liquid separator (18) is communicated with the gas-liquid outlet end of the tail gas mixing ejector (17), the cooling liquid outlet end of the gas-liquid separator (18), the cooling liquid inlet end of the screw vacuum pump (10), the cooling liquid outlet end of the screw vacuum pump (10) and the liquid inlet end of the liquid ring vacuum pump (11) are communicated through a cooling pipeline (36), and a circulating pump (19) is arranged on the cooling pipeline (36);
the first pipeline (31) is communicated with a fourth pipeline (34), and the pressure transmitter (20) is arranged on the fourth pipeline (34);
when the real-time pressure of the pressure transmitter (20) is greater than a preset value, the air inlet two-position three-way pneumatic valve (14) is switched to a first air inlet communicated with an air outlet thereof, a second air inlet is closed with the air outlet thereof, and at the moment, the liquid ring vacuum pump (11) is connected with the screw vacuum pump (10) in parallel; when the real-time pressure value of the pressure transmitter (20) is smaller than or equal to a preset value, the air inlet two-position three-way pneumatic valve (14) is switched to a second air inlet to be communicated with an air outlet of the air inlet two-way pneumatic valve, a first air inlet of the air inlet two-way pneumatic valve is closed to the air outlet of the air inlet two-way pneumatic valve, and the liquid ring vacuum pump (11) is connected with the screw vacuum pump (10) in series at the moment.
2. A screw vacuum pump and liquid ring vacuum pump series-parallel combination system according to claim 1, characterized in that the gas-liquid separator (18) is built-in with a heat exchanger.
3. A screw vacuum pump and liquid ring vacuum pump series-parallel combination system according to claim 1, wherein the gas-liquid separator (18) has a cooling water inlet and a cooling water outlet, the cooling water inlet is communicated with the liquid inlet end of the heat exchanger, and the cooling water outlet is communicated with the liquid discharge end of the heat exchanger.
4. A screw vacuum pump and liquid ring vacuum pump series-parallel combination system according to claim 1, characterized in that the vapor-liquid separator (18) is provided with a temperature transmitter (21).
5. The series-parallel combination system of the screw vacuum pump and the liquid ring vacuum pump as claimed in claim 1, wherein the vapor-liquid separator (18) is provided with a liquid level transmitter (22).
6. A screw vacuum pump and liquid ring vacuum pump series-parallel combination system according to claim 1, characterized in that the exhaust gas mixing ejector (17) is a water ejector.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0569384U (en) * | 1992-02-26 | 1993-09-21 | 豊田工機株式会社 | Tandem pump device for vehicle |
| EP2336590A2 (en) * | 2009-12-15 | 2011-06-22 | Leistritz Pumpen GmbH | Pump aggregate for a double clutch transmission of a motor vehicle |
| CA2866211A1 (en) * | 2012-03-05 | 2013-09-12 | Ateliers Busch Sa | Improved pumping unit and method for controlling such a pumping unit |
| CN104806881A (en) * | 2015-04-03 | 2015-07-29 | 广东省佛山水泵厂有限公司 | Gas-cooled loop-closed Roots liquid vacuum system and control method thereof |
| CN205559228U (en) * | 2016-02-26 | 2016-09-07 | 深圳市国电投资有限公司 | Condenser vacuum of thermal power factory maintains vacuum unit |
| CN109372748A (en) * | 2018-12-05 | 2019-02-22 | 江阴爱尔姆真空设备有限公司 | A kind of vacuum pump set device of screw vacuum and Roots vacuum joint transformation |
| CN209800268U (en) * | 2019-05-10 | 2019-12-17 | 武汉艾德沃泵阀有限公司 | Roots water ring vacuum pump unit |
| KR20200000247U (en) * | 2018-07-20 | 2020-01-30 | 이라이벡 상하이 컴퍼니 리미티드 | Multi-stage energy saving vacuum unit of based roots type main vacuum pump |
| CN111255690A (en) * | 2020-04-01 | 2020-06-09 | 江苏格里克真空技术有限公司 | Straight-line series vacuum pump set |
| CN211737456U (en) * | 2020-01-21 | 2020-10-23 | 云南昆船烟草设备有限公司 | Dry vacuum pump unit for tobacco |
| CN213331520U (en) * | 2020-09-24 | 2021-06-01 | 武汉艾德沃泵阀有限公司 | Air-cooled Roots vacuum pump unit with cylinder cutting function for thermal power industry |
| CN215979896U (en) * | 2021-10-29 | 2022-03-08 | 山东宽量节能环保技术有限公司 | Screw vacuum pump and liquid ring vacuum pump series-parallel combined system |
-
2021
- 2021-10-29 CN CN202111274959.0A patent/CN113982928B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0569384U (en) * | 1992-02-26 | 1993-09-21 | 豊田工機株式会社 | Tandem pump device for vehicle |
| EP2336590A2 (en) * | 2009-12-15 | 2011-06-22 | Leistritz Pumpen GmbH | Pump aggregate for a double clutch transmission of a motor vehicle |
| CA2866211A1 (en) * | 2012-03-05 | 2013-09-12 | Ateliers Busch Sa | Improved pumping unit and method for controlling such a pumping unit |
| CN104806881A (en) * | 2015-04-03 | 2015-07-29 | 广东省佛山水泵厂有限公司 | Gas-cooled loop-closed Roots liquid vacuum system and control method thereof |
| CN205559228U (en) * | 2016-02-26 | 2016-09-07 | 深圳市国电投资有限公司 | Condenser vacuum of thermal power factory maintains vacuum unit |
| KR20200000247U (en) * | 2018-07-20 | 2020-01-30 | 이라이벡 상하이 컴퍼니 리미티드 | Multi-stage energy saving vacuum unit of based roots type main vacuum pump |
| CN109372748A (en) * | 2018-12-05 | 2019-02-22 | 江阴爱尔姆真空设备有限公司 | A kind of vacuum pump set device of screw vacuum and Roots vacuum joint transformation |
| CN209800268U (en) * | 2019-05-10 | 2019-12-17 | 武汉艾德沃泵阀有限公司 | Roots water ring vacuum pump unit |
| CN211737456U (en) * | 2020-01-21 | 2020-10-23 | 云南昆船烟草设备有限公司 | Dry vacuum pump unit for tobacco |
| CN111255690A (en) * | 2020-04-01 | 2020-06-09 | 江苏格里克真空技术有限公司 | Straight-line series vacuum pump set |
| CN213331520U (en) * | 2020-09-24 | 2021-06-01 | 武汉艾德沃泵阀有限公司 | Air-cooled Roots vacuum pump unit with cylinder cutting function for thermal power industry |
| CN215979896U (en) * | 2021-10-29 | 2022-03-08 | 山东宽量节能环保技术有限公司 | Screw vacuum pump and liquid ring vacuum pump series-parallel combined system |
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|---|---|
| CN113982928B (en) | 2024-05-07 |
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