A liquid recovery structure based on mechanical seal of liquid ring vacuum pump

Abstract

The present invention provides a liquid recovery structure based on a mechanical seal for a liquid ring vacuum pump, belonging to the technical field of liquid ring vacuum pumps. It solves the problem in the prior art that the working fluid at the mechanical seal of a liquid ring vacuum pump leaks out and pollutes the environment. The present liquid ring vacuum pump has a liquid recovery structure based on a mechanical seal, and the liquid ring vacuum pump includes a pump body and a rotating shaft rotatably arranged in the pump body, and mechanical seal assemblies are respectively arranged between the two ends of the rotating shaft and the pump body. The liquid recovery structure includes two end covers respectively covered on the two ends of the rotating shaft and connected to the pump body, and a sealed chamber is formed between the end covers and the pump body to accommodate the mechanical seal assembly. The two chambers are respectively connected to the liquid inlet of the pump body through a first return liquid pipe and a second return liquid pipe. The present invention has the advantage of being able to realize the recycling of leaked liquid at the mechanical seal of a liquid ring vacuum pump.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid ring vacuum pumps and relates to a liquid recovery structure of a liquid ring vacuum pump based on mechanical seal. Background Art

[0002] A liquid ring vacuum pump is a variable-volume vacuum pump that uses liquid as an intermediate medium for energy conversion and is used to pump gas. An eccentric rotor with fixed blades is installed in its chamber, which continuously supplies water or liquid to the chamber, driving the rotation. This creates a liquid ring concentric with the stator wall. Therefore, the liquid ring vacuum pump requires a seal on the shaft supporting the rotor to prevent leakage of the working fluid.

[0003] In order to prevent leakage of the working fluid, the existing technology generally adopts a shaft sealing method of mechanical seal assemblies between the two ends of the rotating shaft and the pump body. The mechanical seal assembly includes main components such as a dynamic ring, a static ring and a spring. The dynamic ring is installed on the rotating shaft by an interference fit or a sealing ring to form a radial static seal to prevent the liquid from leaking in the axial direction. The static ring is fixedly connected to the pump body and uses a sealing ring to form a static seal with the pump body to ensure the sealing between the static ring and the pump body. At the same time, the end faces of the dynamic ring and the static ring are tightly fitted under the action of the spring. The dynamic ring and the static ring form a dynamic sealing surface through the compression force of the spring, thereby forming a triple seal between the static seal between the rotating shaft and the dynamic ring, the static seal between the pump body and the static ring, and the dynamic seal between the dynamic ring and the static ring to jointly ensure the sealing. However, after a period of use, the above-mentioned shaft sealing method will have the phenomenon of wear of the dynamic ring and the static ring and aging of the seal, which will cause the mechanical seal to fail and the working fluid to leak from the mechanical seal to the outside of the pump body, thereby causing the working fluid to leak out and pollute the environment. Summary of the Invention

[0004] The purpose of the present invention is to address the above problems in the existing technology and propose a liquid recovery structure based on mechanical seal of liquid ring vacuum pump. The technical problem to be solved by the present invention is how to realize the recovery and utilization of liquid leaked from the mechanical seal of liquid ring vacuum pump.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A liquid ring vacuum pump has a liquid recovery structure based on a mechanical seal. The liquid ring vacuum pump comprises a pump body and a rotating shaft rotatably arranged in the pump body. Mechanical seal assemblies are respectively arranged between the two ends of the rotating shaft and the pump body. The liquid recovery structure is characterized in that the liquid recovery structure comprises two end covers respectively covered on the two end portions of the rotating shaft and connected to the pump body. A sealed chamber is formed between the end covers and the pump body and contains the mechanical seal assembly. The two chambers are respectively connected to the liquid inlet of the pump body through a first liquid return pipe and a second liquid return pipe.

[0007] When the liquid ring vacuum pump is running, the pressure at its liquid inlet is lower than atmospheric pressure, forming a negative pressure state. The liquid recovery structure of the liquid ring vacuum pump based on the mechanical seal forms a closed chamber by setting end covers at the mechanical seal leakage points at both ends of the rotating shaft to physically isolate the contact between the leaked liquid and the environment and collect the leaked liquid in a centralized manner. At the same time, two independent first liquid return pipes and second liquid return pipes are set to connect the two chambers to the liquid inlet of the pump body respectively, thereby utilizing the negative pressure suction force of the liquid inlet of the pump body as the driving force. Without the need for an additional power device, the leaked liquid in the two chambers is actively sucked back into the pump body, realizing a closed-loop circulation circuit of the leaked liquid, thereby realizing the recycling of the leaked liquid at the mechanical seal of the liquid ring vacuum pump and avoiding the leakage of the leaked liquid to pollute the environment.

[0008] In the aforementioned liquid ring vacuum pump's mechanical seal-based liquid recovery structure, the pump body's liquid inlet is connected to a liquid inlet pipe extending from the pump body. The first and second liquid return pipes are respectively connected to the sidewalls of the portion of the liquid inlet pipe extending from the pump body. A removable plug is provided at the end of the liquid inlet pipe extending from the pump body. This allows the liquid inlet pipe to serve as a liquid discharge pipe by removing the plug when the liquid ring vacuum pump is shut down, thus facilitating cleaning of the chamber interior during disassembly and assembly of the liquid ring vacuum pump.

[0009] In the above-mentioned liquid ring vacuum pump liquid recovery structure based on mechanical seal, a PLC controller is provided on the pump body, a liquid level sensor is provided in each of the chambers, and the first return liquid pipe and the second return liquid pipe are respectively provided with a first solenoid valve and a second solenoid valve for controlling on and off. The liquid level sensor, the first solenoid valve and the second solenoid valve are respectively electrically connected to the PLC controller, and the PLC controller can control the opening and closing of the first solenoid valve and the second solenoid valve according to the detection signal of the corresponding liquid level sensor. The liquid level in the chamber is monitored in real time by the liquid level sensor. When the liquid level in the chamber is higher than the set threshold, the PLC controller controls the first solenoid valve or the second solenoid valve corresponding to the chamber to open and discharge the liquid in the chamber into the pump body for recycling. When the liquid level in the chamber drops back to the set threshold, the PLC controller controls the first solenoid valve or the second solenoid valve corresponding to the chamber to close, automatically achieving a dynamic balance of the liquid volume in the chamber. That is, through the linkage between the liquid level sensor, the first solenoid valve, the second solenoid valve and the PLC controller, the full process automation of the "collection-filtration-circulation" closed-loop recovery of the leaked liquid at the mechanical seal of the liquid ring vacuum pump is realized, reducing manual intervention, which is beneficial to improving production efficiency (reducing shutdown frequency) and ensuring the safety of operators in a continuous, toxic and hazardous chemical production environment.

[0010] In the aforementioned liquid ring vacuum pump's mechanical seal-based liquid recovery structure, a first filter and a second filter are further provided on the first and second liquid return pipes, respectively. The first filter is located between the pump body's liquid inlet and the first solenoid valve, and the second filter is located between the pump body's liquid inlet and the second solenoid valve. The first and second filters can remove impurities and particulate matter from leaked liquid, ensuring the cleanliness of the liquid recovered by this liquid recovery structure, protecting pump body components (such as the mechanical seal assembly, impeller, etc.) from wear, extending the service life and reliability of the liquid ring vacuum pump, and reducing the frequency of downtime for maintenance. At the same time, the first and second filters are closer to the pump body's liquid inlet, ensuring that the recovered liquid entering the pump body's liquid inlet is filtered, thereby better ensuring the cleanliness of the liquid recovered by this liquid recovery structure.

[0011] In the above-mentioned liquid ring vacuum pump liquid recovery structure based on mechanical seal, the two end covers are respectively provided with windows for observing the internal conditions. The provision of the windows facilitates the operator to visually observe the conditions in the two chambers, thereby ensuring the normal operation of the liquid recovery structure.

[0012] In the aforementioned liquid ring vacuum pump liquid recovery structure based on a mechanical seal, the inner circumferential wall of the end cover has an annular mounting portion, to which an oil seal is connected. The oil seal is mounted on the rotating shaft and forms a seal against the rotating shaft. The oil seal divides the chamber into an oil storage chamber and a liquid storage chamber. The oil storage chamber contains lubricating oil. A bearing located in the oil storage chamber is provided between the rotating shaft and the end cover. The first liquid return pipe and the second liquid return pipe are both connected to the liquid storage chamber. The oil seal divides the chamber into the oil storage chamber and the liquid storage chamber, and a bearing is provided in the oil storage chamber containing lubricating oil to support the rotating shaft and reduce friction between the rotating shaft and the mechanical seal assembly (the lubricating oil in the oil storage chamber will not enter the liquid storage chamber due to the obstruction of the oil seal), thereby extending the service life and reliability of the liquid ring vacuum pump.

[0013] Compared with the existing technology, the advantages of the liquid recovery structure based on mechanical seal of the liquid ring vacuum pump are: the liquid recovery structure based on mechanical seal of the liquid ring vacuum pump forms a closed chamber by setting end covers at the mechanical seal leakage points at both ends of the rotating shaft to physically isolate the contact between the leaked liquid and the environment and collect the leaked liquid in a centralized manner. At the same time, two independent first liquid return pipes and second liquid return pipes are set to connect the two chambers to the liquid inlet of the pump body respectively, thereby utilizing the negative pressure suction force of the liquid inlet of the pump body as the driving force, and without the need for an additional power device, actively sucking the leaked liquid in the two chambers back into the pump body to realize a closed-loop circulation circuit of the leaked liquid, thereby realizing the recycling of the leaked liquid at the mechanical seal of the liquid ring vacuum pump and avoiding the leakage of the leaked liquid to pollute the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is one of the three-dimensional structural diagrams of the liquid recovery structure of the liquid ring vacuum pump based on mechanical seal.

[0015] Figure 2 This is the second three-dimensional structural diagram of the liquid recovery structure of the liquid ring vacuum pump based on mechanical seal.

[0016] Figure 3 This is a cross-sectional view of the liquid recovery structure of the liquid ring vacuum pump based on the mechanical seal.

[0017] Figure 4 yes Figure 3 A partial enlarged view of point A in the middle.

[0018] In the figure, 1. pump body; 1a. liquid inlet; 2. rotating shaft; 3. mechanical seal assembly; 4. end cover; 4a. annular mounting portion; 5. chamber; 5a. oil storage chamber; 5b. liquid storage chamber; 6. first liquid return pipe; 7. second liquid return pipe; 8. liquid inlet pipe; 9. plug; 10. liquid level sensor; 11. first solenoid valve; 12. second solenoid valve; 13. first filter; 14. second filter; 15. window; 16. oil seal; 17. bearing. DETAILED DESCRIPTION

[0019] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0020] A liquid ring vacuum pump based on the liquid recovery structure of the mechanical seal, refer to Figure 1-4 The liquid ring vacuum pump includes a pump body 1 and a rotating shaft 2 rotatably arranged in the pump body 1, and mechanical seal assemblies 3 are respectively arranged between the two ends of the rotating shaft 2 and the pump body 1. The liquid recovery structure includes two end covers 4 respectively covered on the two ends of the rotating shaft 2 and connected to the pump body 1, and a closed chamber 5 is formed between the end cover 4 and the pump body 1 and accommodating the mechanical seal assembly 3. The two chambers 5 are respectively connected to the liquid inlet 1a of the pump body 1 through a first liquid return pipe 6 and a second liquid return pipe 7.

[0021] Reference Figure 3 and Figure 4 Specifically, an annular mounting portion 4a is provided on the inner circumferential wall of the end cover 4, and an oil seal 16 is connected to the annular mounting portion 4a. The oil seal 16 is sleeved on the rotating shaft 2 and forms a sealing abutment with the rotating shaft 2. The oil seal 16 divides the chamber 5 into an oil storage chamber 5a and a liquid storage chamber 5b. The oil storage chamber 5a is filled with lubricating oil. A bearing 17 is provided between the rotating shaft 2 and the end cover 4 and is located in the oil storage chamber 5a. The first liquid return pipe 6 and the second liquid return pipe 7 are both connected to the liquid storage chamber 5b.

[0022] Reference Figure 1 and Figure 3 Furthermore, the liquid inlet 1a of the pump body 1 is connected to a liquid inlet pipe 8 extending from the pump body 1, and the side walls of the liquid inlet pipe 8 extending from the pump body 1 are respectively connected to the first liquid return pipe 6 and the second liquid return pipe 7, and a detachable plug 9 is provided on the end of the liquid inlet pipe 8 extending from the pump body 1.

[0023] Reference Figure 1 、 Figure 2 and Figure 3 Furthermore, the pump body 1 is provided with a PLC controller (not shown in the figure, the PLC controller of this embodiment can adopt an existing controller, generally speaking, as long as it has the function of collecting liquid level sensor signals and controlling the opening / closing of the solenoid valve), each of the chambers 5 is provided with a liquid level sensor 10, and the first return liquid pipe 6 and the second return liquid pipe 7 are respectively provided with a first solenoid valve 11 and a second solenoid valve 12 for controlling the on-off. The liquid level sensor 10, the first solenoid valve 11 and the second solenoid valve 12 are respectively electrically connected to the PLC controller, and the PLC controller can control the opening and closing of the first solenoid valve 11 and the second solenoid valve 12 according to the detection signals of the corresponding liquid level sensors 10.

[0024] Reference Figure 1 、 Figure 2 and Figure 3 Furthermore, a first filter 13 and a second filter 14 are respectively provided on the first liquid return pipe 6 and the second liquid return pipe 7, and the first filter 13 is located between the liquid inlet 1a of the pump body 1 and the first solenoid valve 11, and the second filter 14 is located between the liquid inlet 1a of the pump body 1 and the second solenoid valve 12.

[0025] In this embodiment, the two end covers 4 are preferably provided with windows 15 for observing the internal conditions.

[0026] When the liquid ring vacuum pump is in operation, the pressure at its liquid inlet 1a is lower than atmospheric pressure, forming a negative pressure state. The liquid recovery structure of the liquid ring vacuum pump based on the mechanical seal forms a sealed chamber 5 by providing end covers 4 at the mechanical seal leakage points at both ends of the rotating shaft 2 to physically isolate the leaked liquid from contact with the environment and collect the leaked liquid in a centralized manner. At the same time, two independent first liquid return pipes 6 and second liquid return pipes 7 are provided to connect the two chambers 5 to the liquid inlet 1a of the pump body 1, respectively. Thus, the negative pressure suction of the liquid inlet 1a of the pump body 1 is used as the driving force. Without the need for an additional power device, the leaked liquid in the two chambers 5 is actively sucked back into the pump body 1, realizing a closed-loop circulation circuit for the leaked liquid, thereby realizing the recovery and utilization of the leaked liquid at the mechanical seal of the liquid ring vacuum pump, achieving "zero escape" of the leaked liquid, and preventing the leaked liquid from leaking and polluting the environment. The redundant design of the first liquid return pipe 6 and the second liquid return pipe 7 improves the reliability of the liquid recovery structure. At the same time, the use of the negative pressure suction of the liquid inlet 1a of the pump body 1 as the driving force is energy-saving and efficient, and the liquid recovery rate is increased by more than 30%.

[0027] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A liquid ring vacuum pump liquid recovery structure based on mechanical seal, the liquid ring vacuum pump comprising a pump body (1) and a rotating shaft (2) rotatably arranged in the pump body (1), mechanical seal components (3) are respectively arranged between the two ends of the rotating shaft (2) and the pump body (1), characterized in that: The liquid recovery structure comprises two end covers (4) respectively arranged on the two ends of the rotating shaft (2) and connected to the pump body (1); a sealed chamber (5) containing the mechanical seal assembly (3) is formed between the end covers (4) and the pump body (1); the two chambers (5) are respectively connected to the liquid inlet (1a) of the pump body (1) through a first liquid return pipe (6) and a second liquid return pipe (7); the liquid inlet (1a) of the pump body (1) is connected to a liquid inlet pipe (8) extending from the pump body (1); the side walls of the portion where the liquid inlet pipe (8) extends from the pump body (1) are respectively connected to the first liquid return pipe (6) and the second liquid return pipe (7); the liquid inlet pipe (8) extending from the pump body (1) is connected to the first liquid return pipe (6) and the second liquid return pipe (7). A plug (9) is detachably provided on the end of the pump body (1), an annular mounting portion (4a) is provided on the inner peripheral wall of the end cover (4), an oil seal (16) is connected to the annular mounting portion (4a), the oil seal (16) is sleeved on the rotating shaft (2) and forms a sealing abutment with the rotating shaft (2), the oil seal (16) divides the chamber (5) into an oil storage chamber (5a) and a liquid storage chamber (5b), the oil storage chamber (5a) contains lubricating oil, a bearing (17) is provided in the oil storage chamber (5a) between the rotating shaft (2) and the end cover (4), and the first liquid return pipe (6) and the second liquid return pipe (7) are both connected to the liquid storage chamber (5b).

2. A liquid recovery structure based on mechanical seal of a liquid ring vacuum pump according to claim 1, characterized in that: The pump body (1) is provided with a PLC controller, each of the chambers (5) is provided with a liquid level sensor (10), the first return liquid pipe (6) and the second return liquid pipe (7) are respectively provided with a first solenoid valve (11) and a second solenoid valve (12) for controlling on and off, the liquid level sensor (10), the first solenoid valve (11) and the second solenoid valve (12) are respectively electrically connected to the PLC controller, and the PLC controller can control the opening and closing of the first solenoid valve (11) and the second solenoid valve (12) according to the detection signal of the corresponding liquid level sensor (10).

3. A liquid ring vacuum pump liquid recovery structure based on mechanical seal according to claim 2, characterized in that: A first filter (13) and a second filter (14) are also provided on the first liquid return pipe (6) and the second liquid return pipe (7), respectively. The first filter (13) is located between the liquid inlet (1a) of the pump body (1) and the first solenoid valve (11), and the second filter (14) is located between the liquid inlet (1a) of the pump body (1) and the second solenoid valve (12).

4. A liquid recovery structure based on mechanical seal of a liquid ring vacuum pump according to claim 2, characterized in that: The two end covers (4) are respectively provided with windows (15) for observing the internal conditions.

Images