An explosion-proof rotary vane vacuum pump for oil and gas recovery devices

Abstract

This utility model relates to the field of vacuum pump technology and discloses an explosion-proof rotary vane vacuum pump for oil and gas recovery devices. It aims to solve the technical problems of insufficient sealing performance, low ultimate vacuum, and susceptibility to failure and oil leakage in traditional rotary vane pumps operating under positive pressure. This explosion-proof rotary vane vacuum pump includes a pump body with a rotor rotatably mounted inside. Sliding vanes are mounted on the rotor. A front pump cover and a rear pump cover are connected to the front and rear ends of the pump body, respectively. A bidirectional oil seal (skeletal oil seal) is installed at the shaft hole of the rear pump cover. The bidirectional oil seal structure is configured to prevent oil leakage under high pressure and to prevent external air from entering under negative pressure. An oil and gas outlet is provided on the pump body, and a pressure monitoring component is installed at the outlet to monitor fluid pressure. This utility model optimizes the skeleton oil seal, improves the working capacity of the vacuum pump under positive pressure, reduces the oil leakage rate, monitors the outlet pressure in real time, and protects the vacuum pump.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum pumps, in particular to an explosion-proof rotary vane vacuum pump for an oil and gas recovery device. Background Art

[0002] Oil and gas recovery is a crucial environmental protection and safe production link in industries such as petroleum and petrochemical, storage and transportation loading and unloading, etc. Its core purpose is to recover the volatile organic gases (VOCs) during the storage and transportation of oil products, preventing them from being directly discharged into the atmosphere, causing pollution and waste of resources. The activated carbon adsorption method is one of the most widely used oil and gas recovery technologies at present. This process is mainly divided into two stages: adsorption and desorption. In the adsorption stage, the oil and gas are adsorbed by the activated carbon in the adsorption tank. In the desorption stage, a negative pressure needs to be applied to the adsorption tank by a vacuum pump to desorb the oil and gas adsorbed on the activated carbon, forming an enriched oil and gas mixture, which is then sent to a condensation device for liquefaction recovery. The rotary vane vacuum pump is often selected as the power source for the above desorption process due to its compact structure and relatively high pumping efficiency. However, directly applying an ordinary rotary vane vacuum pump to an oil and gas recovery device has significant safety hazards and technical defects.

[0003] The Chinese patent document in the prior art: 202510185694.9 discloses a rotary vane vacuum pump, including a pump housing, a rotor, rotary vanes, and an adjusting frame. There is a pump chamber inside the pump housing. The rotor is eccentrically arranged in the pump chamber and can rotate around its axis. There are multiple rotary vanes, which are circumferentially spaced around the rotor and elastically connected to the rotor. The rotary vanes can elastically slide along the radial direction of the rotor.

[0004] However, during the implementation of the above solution, there are at least the following technical problems: the traditional rotary vane pump has insufficient sealing performance and low ultimate vacuum degree; it is prone to malfunction and oil leakage during operation in a positive pressure environment; when there is air resistance in the exhaust port or exhaust pipe, the motor is easily damaged; the check valve at the pump inlet and the cooling fan are made of plastic, which is easy to accumulate static electricity and has potential hazards; the rotary vanes and the rotor are made of aluminum alloy, which has safety hazards. Therefore, there is an urgent need to propose an explosion-proof rotary vane vacuum pump for an oil and gas recovery device. Summary of the Utility Model

[0005] In view of the above technical problems, the present disclosure provides an explosion-proof rotary vane vacuum pump for an oil and gas recovery device, which solves the technical problems in the prior art that the traditional rotary vane pump has insufficient sealing performance and low ultimate vacuum degree; it is prone to malfunction and oil leakage during operation in a positive pressure environment; when there is air resistance in the exhaust port or exhaust pipe, the motor is easily damaged; the check valve at the pump inlet and the cooling fan are made of plastic, which is easy to accumulate static electricity and has potential hazards; the rotary vanes and the rotor are made of aluminum alloy, which has safety hazards.

[0006] According to one aspect of this disclosure, an explosion-proof rotary vane vacuum pump is provided for an oil and gas recovery device. The oil and gas recovery device includes an adsorption tank connected to the oil and gas inlet of the explosion-proof rotary vane vacuum pump. The oil and gas mixture compressed by the explosion-proof rotary vane vacuum pump is discharged through the oil and gas outlet to the return oil pipeline of the oil and gas recovery device. The explosion-proof rotary vane vacuum pump includes a pump body, in which a rotor is rotatably mounted. Sliding vanes are provided on the rotor. A front pump cover and a rear pump cover are respectively connected to the front and rear ends of the pump body. A skeleton oil seal with a bidirectional oil seal is provided at the shaft hole of the rear pump cover. The bidirectional oil seal structure of the skeleton oil seal is configured to prevent oil leakage under high pressure in the pump and to prevent external air from entering under negative pressure in the pump. An oil and gas outlet is provided on the pump body, and a pressure monitoring component for monitoring fluid pressure is installed at the oil and gas outlet.

[0007] In some embodiments of this disclosure, the pressure monitoring component includes a mechanical pressure switch or a pressure sensor.

[0008] In some embodiments of this disclosure, the rotor is made of 316L stainless steel, and the operating clearance between the outer circumferential surface of the rotor and the inner wall of the pump body is 0.07~0.08mm.

[0009] In some embodiments of this disclosure, the slider is made of graphite material.

[0010] In some embodiments of this disclosure, the rotor is mounted on the rear pump cover via a needle roller bearing without an inner ring and a first rubber seal. A fan is provided on the shaft end of the rotor extending out of the rear pump cover. The fan is located inside a fan cover. A piston support plate is mounted on the pump body via a second rubber seal. A piston is mounted on the piston support plate. A piston outer sleeve is provided on the outside of the piston. A filter screen is mounted on the piston via a third rubber seal. An oil and gas inlet is provided above the filter screen.

[0011] In some embodiments of this disclosure, both the fan and the piston are made of a non-aluminum alloy metal material that does not generate tribostatic electricity.

[0012] In some embodiments of this disclosure, the non-aluminum alloy metal material that does not generate tribostatic electricity is Q235 steel.

[0013] In some embodiments of this disclosure, an explosion-proof three-phase asynchronous motor is mounted on the rotor via a connector. The connector is mounted on the outside with screws and spring washers, and a coupling is provided on the inside of the connector to connect the rotor shaft and the motor's power output shaft.

[0014] In some embodiments of this disclosure, an oil reservoir is fixedly installed on the rear pump cover of the vacuum pump, and the oil reservoir contains mineral oil-type vacuum pump oil.

[0015] In some embodiments of this disclosure, a nameplate is mounted on the oil tank by rivets.

[0016] The beneficial effects of this utility model are as follows: 1. A pressure switch is added to the pump outlet to monitor the outlet pressure in real time and protect the vacuum pump; the pressure monitoring component (pressure switch or pressure sensor) can monitor the pump's operating status in real time. This system can realize overpressure protection, interlock start-stop and other functions, providing key data support and control nodes for the automated and safe operation of the entire oil and gas recovery unit.

[0017] 2. Optimized skeleton oil seal improves the vacuum pump's working capacity under positive pressure and reduces oil leakage rate. A skeleton oil seal with a two-way oil seal at the rear pump cover shaft hole has a unique structure that can simultaneously handle two extreme operating conditions within the pump: preventing vacuum pump oil leakage during the high-pressure exhaust phase and preventing external air from entering the pump during the vacuuming phase. This not only maintains oil cleanliness and pump vacuum, but more importantly, it prevents air from entering the system and forming an explosive mixture, greatly improving safety.

[0018] 3. The rotor material has been upgraded to 316L, which can reduce the gap between the rotor and the pump chamber and improve the vacuum level; it is made of stainless steel, which has excellent corrosion resistance and mechanical strength, can resist the erosion of oil and gas, and ensure the stability of long-term operation.

[0019] 4. The sliding plate material has been upgraded to graphite, which improves operational safety; it has self-lubricating properties, a low coefficient of friction, and low wear, and the conductivity of graphite can prevent static electricity accumulation, further improving operational reliability and service life.

[0020] 5. The fan and piston materials have been upgraded to Q235, improving operational safety; the metal material does not generate static electricity, eliminating the possibility of sparks caused by collisions and friction of parts, thus providing double explosion-proof protection.

[0021] 6. Reduced after-sales maintenance costs. Using an explosion-proof three-phase asynchronous motor as the power source eliminates the risk of electrical sparks igniting explosive gases at the source.

[0022] The gap between the rotor and the inner wall of the pump body is precisely controlled at 0.07~0.08mm. This optimized gap ensures high pumping and compression efficiency while avoiding direct metal-to-metal contact wear, ensuring smooth operation and low noise.

[0023] The independent oil tank design facilitates the filling and replacement of vacuum pump oil.

[0024] The filter effectively filters impurities in the oil and gas, protects the pump's internal components, and extends maintenance intervals.

[0025] The product features a reasonable structural layout, uses spring washers to prevent loosening at key connection points, and includes a fan cover, all of which improve its practicality and safety. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an explosion-proof rotary vane vacuum pump used in an oil and gas recovery device. Figure 2 A schematic diagram of the internal structure of the rotor of an explosion-proof rotary vane vacuum pump used in an oil and gas recovery device; Figure 3 for Figure 2 Sectional view of plane AA; Figure 4 This is a structural diagram of a skeleton oil seal; Figure 5 A schematic diagram of the skeleton oil seal from another perspective; The components in the diagram are as follows: 1. Fan cover; 2. Key; 3. Oil seal; 4. Elastic retaining ring for bore; 5. Fan; 6. Needle roller bearing without inner ring; 7. Rear pump cover; 8. First rubber seal; 9. Pump body; 10. Second rubber seal; 11. Piston support plate; 12. Piston; 13. Filter screen; 14. Third rubber seal; 15. Oil / gas inlet; 16. Piston outer sleeve; 17. Rotor; 18. Front pump cover; 19. Explosion-proof three-phase asynchronous motor; 20. Screw; 21. Spring washer; 22. Coupling; 23. Connecting piece; 24. Cross-head pan head screw; 25. Second screw; 26. Second spring washer; 27. Oil reservoir; 28. Rivet; 29. ​​Nameplate; 30. Sliding vane; 31. Pressure monitoring component; 32. Oil / gas outlet. Detailed Implementation

[0027] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1

[0028] This example discloses an explosion-proof rotary vane vacuum pump for use in oil and gas recovery devices. See [link to relevant documentation]. Figures 1 to 5 The oil and gas recovery device includes an adsorption tank, which is connected to the oil and gas inlet of an explosion-proof rotary vane vacuum pump. The oil and gas mixture compressed by the explosion-proof rotary vane vacuum pump is discharged through the oil and gas outlet to the return oil pipeline of the oil and gas recovery device. The explosion-proof rotary vane vacuum pump includes a pump body 9, a rotor 17 is rotatably installed inside the pump body 9, and a sliding vane 30 is provided on the rotor 17. The front end and rear end of the pump body 9 are respectively connected to a front pump cover 18 and a rear pump cover 7. A skeleton oil seal 3 with a bidirectional oil seal is provided at the shaft hole of the rear pump cover 7. The bidirectional oil seal structure of the skeleton oil seal 3 is configured to prevent oil leakage when the pump is under high pressure and to prevent external air from entering when the pump is under negative pressure. An oil and gas outlet 32 ​​is opened on the pump body 9, and a pressure monitoring component 31 for monitoring fluid pressure is installed at the oil and gas outlet 32.

[0029] The pressure monitoring component 31 includes a mechanical pressure switch or a pressure sensor.

[0030] The rotor 17 is made of 316L stainless steel, and the operating clearance between the outer circumferential surface of the rotor 17 and the inner wall of the pump body 9 is 0.07~0.08mm.

[0031] The slider 30 is made of graphite material.

[0032] The rotor 17 is mounted on the pump cover 7 via the inner ring needle roller bearing 6 and the first rubber seal ring 8. The fan 5 is mounted on the shaft end of the rotor 17 extending out of the pump cover 7 via the flat key 2. The top mounting hole of the rotor shaft is fitted with an elastic retaining ring 4. The fan 5 is located inside the fan cover 1. The pump body 9 is mounted on the piston support plate 11 via the second rubber seal ring 10. The piston 12 is mounted on the piston support plate 11. The piston outer sleeve 16 is mounted on the outside of the piston 12. The filter screen 13 is mounted on the piston 12 via the third rubber seal ring 14. The oil and gas inlet 15 is located above the filter screen 13.

[0033] The fan cover 1 is installed using cross-slot pan head screws 24.

[0034] Both the fan 5 and the piston 12 are made of non-aluminum alloy metal that does not generate triboelectric static electricity.

[0035] The non-aluminum alloy metal material that does not generate tribostatic static electricity is Q235 steel.

[0036] The rotor 17 is mounted with an explosion-proof three-phase asynchronous motor 19 via a connector 23. The connector 23 is mounted on the outside via screws 20 and spring washers 21. A coupling 22 is provided on the inside of the connector 23 to connect the rotating shaft of the rotor 17 and the power output shaft of the motor.

[0037] An oil reservoir 27 is installed on the rear pump cover 7 of the vacuum pump via a second screw 25 and a second spring washer 26. The oil reservoir 27 contains mineral oil-type vacuum pump oil.

[0038] A nameplate 29 is installed on the oil tank 27 by rivets 28.

[0039] Skeleton oil seal. Based on the traditional unidirectional oil seal, it has been improved into a bidirectional oil seal. This prevents high pressure inside the pump from pushing the oil seal out and causing oil leakage, and ensures that atmospheric pressure tightly compresses the oil seal when there is negative pressure inside the pump. This makes the vacuum pump more suitable for applications in tertiary oil-gas recovery systems.

[0040] The fan and piston are made of Q235 material, an improvement over the traditional PC material, to ensure that no static electricity is generated during operation.

[0041] Rotor. Upgraded from traditional aluminum alloy to 316L material, allowing for a smaller gap between the rotor and the pump chamber, between 0.07mm and 0.08mm. This smaller gap improves the ultimate vacuum level of the vacuum pump. Additionally, the 316L material offers greater stability and corrosion resistance during long-term operation.

[0042] Sliding vane. The sliding vane material has been upgraded to graphite, which has good electrical conductivity and does not produce sparks or rapid heating like metal materials when rubbing against the pump body, making it more suitable for use in hazardous gas environments.

[0043] Pressure switch. The outlet pressure of a rotary vane vacuum pump should not be too high, as excessive outlet pressure can reduce vacuum levels or even damage the pump or drive motor. This invention incorporates a pressure switch at the pump's oil / gas outlet to monitor the outlet pressure in real time. When the pressure increases to the switch's activation value, it outputs a switching signal as an alarm. This signal can be connected to a PLC to implement protection logic, preventing damage to the vacuum pump.

[0044] During operation, the adsorption tank of the oil and gas recovery unit has just completed the adsorption process of oil and gas, and the adsorbent (such as activated carbon) inside the tank is nearly saturated. At this time, the vacuum pump is stopped. A two-way skeleton oil seal ensures that the oil in the pump chamber will not leak, while preventing air from entering. The control system issues a command, and the explosion-proof three-phase asynchronous motor starts, driving the rotor to rotate at high speed through the coupling. The rotor drives the graphite vanes to be thrown out under the action of centrifugal force, closely adhering to the inner wall of the pump body, forming a constantly changing sealed cavity. This process generates a strong vacuum suction at the oil and gas inlet of the adsorption tank and the pump. The pressure inside the tank drops rapidly, causing the oil and gas molecules adsorbed on the adsorbent to desorb, forming an oil and gas mixture. The desorbed oil and gas mixture is filtered by a filter screen to remove any solid particles and is then sucked into the vacuum pump chamber. The piston and piston support plate structure act as a check valve or airflow guide. As the rotor continues to rotate, the sucked oil and gas mixture is gradually compressed by the cavity separated by the vanes, and the pressure and temperature rise. The pressure monitoring component monitors the pressure at the oil and gas outlet in real time. The discharged high-pressure, high-concentration oil and gas is sent to the subsequent return oil pipeline, typically entering a condenser where the oil and gas are condensed and liquefied into gasoline for recovery. A fan rotates with the rotor shaft, providing forced air cooling to the pump body, removing heat generated during compression and preventing overheating. Vacuum pump oil in the reservoir continuously lubricates the pump chamber and helps seal the tiny gaps between the rotor and the pump body, while also aiding in cooling. When the oil and gas in the adsorption tank are fully desorbed and the pressure or concentration reaches the set standard, the control system commands the motor to stop, and the vacuum pump shuts down. At this point, the pressure inside the pump tends to balance. The bidirectional skeleton oil seal again plays a crucial role, ensuring that external air is not drawn into the system under the negative pressure environment that may arise during pump cooling, thus protecting the purity of the recovered oil and preventing the formation of explosive mixtures.

[0045] Although some preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0046] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this application and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An explosion-proof rotary vane vacuum pump for an oil and gas recovery device, the oil and gas recovery device including an adsorption tank, the adsorption tank being connected to the oil and gas inlet of the explosion-proof rotary vane vacuum pump, the oil and gas mixture compressed by the explosion-proof rotary vane vacuum pump being discharged through the oil and gas outlet to the return oil pipeline of the oil and gas recovery device, characterized in that: An explosion-proof rotary vane vacuum pump includes a pump body, in which a rotor is rotatably mounted. Sliding vanes are mounted on the rotor. A front pump cover and a rear pump cover are connected to the front and rear ends of the pump body, respectively. A bidirectional oil seal skeleton is installed at the shaft hole of the rear pump cover. The bidirectional oil seal skeleton is configured to prevent oil leakage under high pressure and to prevent external air from entering under negative pressure. An oil / gas outlet is provided on the pump body, and a pressure monitoring component for monitoring fluid pressure is installed at the oil / gas outlet.

2. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 1, characterized in that: The pressure monitoring component includes a mechanical pressure switch or a pressure sensor.

3. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 1, characterized in that: The rotor is made of 316L stainless steel, and the operating clearance between the outer circumferential surface of the rotor and the inner wall of the pump body is 0.07~0.08mm.

4. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 1, characterized in that: The slider is made of graphite material.

5. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 1, characterized in that: The rotor is mounted on the pump cover via a needle roller bearing without an inner ring and a first rubber seal. A fan is installed on the shaft end of the rotor extending out of the pump cover. The fan is located inside a fan cover. A piston support plate is mounted on the pump body via a second rubber seal. A piston is mounted on the piston support plate. A piston sleeve is installed on the outside of the piston. A filter screen is mounted on the piston via a third rubber seal. An oil and gas inlet is located above the filter screen.

6. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 5, characterized in that: Both the fan and piston are made of non-aluminum alloy metal materials that do not generate tribostatic electricity.

7. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 6, characterized in that: The non-aluminum alloy metal material that does not generate tribostatic electricity is Q235 steel.

8. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 1, characterized in that: An explosion-proof three-phase asynchronous motor is mounted on the rotor via a connector. The connector is mounted on the outside with screws and spring washers, and a coupling is installed on the inside of the connector to connect the rotor shaft and the motor's power output shaft.

9. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 1, characterized in that: An oil reservoir is fixedly installed on the rear pump cover of the vacuum pump, and the oil reservoir is filled with mineral oil-type vacuum pump oil.

10. The explosion-proof rotary vane vacuum pump for an oil and gas recovery device as described in claim 9, characterized in that: A nameplate is mounted on the oil storage tank using rivets.

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