Mechanical seal system for automatic liquid replenishing pump

Abstract

The present application discloses a mechanical seal system for an automatic liquid replenishing pump, comprising: multiple mechanical seal sets, multiple seal circulation systems, an automatic liquid replenishing system, and a control system. The multiple mechanical seal sets are respectively arranged corresponding to multiple series-connected pump sets, each mechanical seal set comprises multi-stage seals, and the multi-stage seals are respectively arranged on multi-stage pumps of the corresponding series-connected pump set; liquid inlets and liquid outlets of the multiple seal circulation systems are respectively correspondingly connected to liquid outlets and liquid inlets of the multi-stage seals; the automatic liquid replenishing system comprises a liquid storage unit, a pumping unit, and multiple liquid replenishing units respectively connected to the seal circulation systems; a liquid outlet of the liquid storage unit is connected to the liquid replenishing units by means of the pumping unit; and the control system is connected to the liquid replenishing units. The present application is capable of outputting gradient pressures in parallel according to different terminal pressure requirements, thereby effectively managing the pressure gradients within seal cavities during operation of series-connected pump sets and improving the overall efficiency and reliability of the system.

Description

Mechanical seal system for automatic liquid supplement pump TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical seals, in particular to a mechanical seal system for an automatic liquid supplement pump. BACKGROUND

[0002] Slurry pumps are widely used in the mining industry and are mainly used to transport suspensions containing solid particles, which can be ore fragments mined from mines or by-products generated during processing. The design of slurry pumps must take into account the harsh environment in which they operate, as they often need to handle high concentrations of abrasive and corrosive media. Mechanical seals (referred to as mechanical seals) are one of the important components of slurry pumps, and their main function is to prevent the leakage of fluids inside the pump to the outside or the entry of foreign matter from the outside into the pump.

[0003] Publication No. CN204921968U provides a mechanical seal system for a fully automatic adjustment-circulation system, which includes a holding container, a safety valve, a liquid level sight glass, a liquid level transmitter, a discharge valve, an inlet sealing circulation path, an outlet sealing circulation path, a container pressure increase-decrease path, and a container liquid supplement path. When all the pipelines are connected, the liquid level transmitter is interlocked with the plunger pump and the electric shut-off valve. When the system is started, the plunger pump is automatically started, the electric shut-off valve is opened, and the barrier liquid is pumped into the system pipeline and into the holding container. When the liquid level reaches the high position, the liquid level transmitter sends a signal to stop the plunger pump and automatically close the electric shut-off valve. When the barrier liquid is consumed to the low position, the liquid level transmitter sends a signal to supplement the liquid.

[0004] However, in a multi-stage pump system, due to the large pressure difference between the pumps, the pressure management of the sealing system becomes particularly important. Inappropriate pressure distribution can lead to sealing failure, leakage and other problems, thereby affecting the overall performance and safety of the pump. Therefore, it is necessary to reasonably design and implement a sealing pressure gradient control strategy.

[0005] SUMMARY

[0006] The present application aims to overcome the above technical deficiencies and proposes a mechanical seal system for an automatic liquid supplement pump to solve the technical problem that the liquid supplement system in the prior art is difficult to apply to a multi-stage pump system.

[0007] To achieve the above technical purpose, the present application adopts the following technical scheme:

[0008] The application provides an automatic liquid supplement pump mechanical seal system, which comprises a plurality of mechanical seals, a plurality of sealing circulation systems, an automatic liquid supplement system and a control system, the plurality of mechanical seals correspond to a plurality of series pump groups respectively, each mechanical seal comprises a plurality of seals, and the plurality of seals are arranged on a plurality of pumps of the series pump group; the liquid inlet and the liquid outlet of the plurality of sealing circulation systems are connected to the liquid outlet and the liquid inlet of the plurality of seals respectively, and are used for circulating and heat-exchanging the barrier liquid in the mechanical seal; the automatic liquid supplement system comprises a liquid storage unit, a pumping unit and a plurality of liquid supplement units connected to the sealing circulation systems respectively, the liquid outlet of the liquid storage unit is connected to the liquid supplement units through the pumping unit, so that the pipeline pressure in the liquid supplement unit is maintained through the pumping unit; and the control system is connected to the liquid supplement unit, so as to control the liquid supplement unit to supplement the set pressure to the corresponding sealing circulation system according to the pressure required by each seal in the mechanical seal.

[0009] In some embodiments, as the pressure in the plurality of pumps of the series pump group gradually increases, the pressure value provided by the liquid supplement unit to the sealing circulation system corresponding to the plurality of pumps gradually increases.

[0010] In some embodiments, each sealing circulation system comprises a heat exchanger, a first accumulator and a first circulating pump, the liquid inlet of the heat exchanger is connected to the liquid outlet of the mechanical seal through a first pipeline, the liquid outlet of the heat exchanger is connected to the liquid inlet of the mechanical seal through a second pipeline, and a cooling water inlet and a cooling water outlet for the cooling liquid are further arranged on the heat exchanger; the second pipeline is connected to the first accumulator through a third pipeline, and the other end of the third pipeline is connected to the liquid supplement unit through a first liquid inlet pipeline; and the first circulating pump is installed on the second pipeline, and is used for providing driving force for the circulation of the cooling liquid between the heat exchanger and the mechanical seal.

[0011] In some embodiments, each sealing circulation system further comprises a second liquid inlet pipeline, a gate valve, a quick connector and a first check valve, the second liquid inlet pipeline is connected to the third pipeline in parallel with the first liquid inlet pipeline, and the third pipeline is sequentially provided with the quick connector, the gate valve and the first check valve along the flow direction of the cooling liquid.

[0012] In some embodiments, each of the sealing circulation systems further comprises a first valve group, a first temperature transmitter, a sight glass, a first pressure gauge, a first pressure transmitter, a second valve group, a first ball valve, a first needle valve, a first flow transmitter, a second ball valve, and a second needle valve, the first valve group, the first temperature transmitter, and the sight glass are sequentially arranged on the first pipeline, the first pressure gauge is connected with the first valve group; the first pressure transmitter is connected with the third pipeline through the second valve group; the first ball valve is connected with the third pipeline; the first needle valve, the first flow transmitter, and the second ball valve are sequentially connected with the first liquid inlet pipeline; the fourth pipeline connected with the liquid inlet and liquid outlet of the first liquid inlet pipeline is further arranged on the first liquid inlet pipeline, and the second needle valve is arranged on the fourth pipeline.

[0013] In some embodiments, each of the series pump groups is provided with three levels, respectively comprising a first pump, a second pump, and a third pump; each of the multi-level seals comprises a first seal, a second seal, and a third seal, a plurality of groups of the first seals are respectively arranged on a plurality of groups of the first pumps, a plurality of groups of the second seals are respectively arranged on a plurality of groups of the second pumps, and a plurality of groups of the third seals are respectively arranged on a plurality of groups of the third pumps; a plurality of groups of the sealing circulation systems respectively comprise a first sealing circulation system, a second sealing circulation system, and a third sealing circulation system, the liquid inlet of the first sealing circulation system is in communication with the liquid outlet of a plurality of groups of the first seals, the liquid outlet of the first sealing circulation system is in communication with the liquid inlet of a plurality of groups of the first seals, the liquid inlet of the second sealing circulation system is in communication with the liquid outlet of a plurality of groups of the second seals, the liquid outlet of the second sealing circulation system is in communication with the liquid inlet of a plurality of groups of the second seals, the liquid inlet of the third sealing circulation system is in communication with the liquid outlet of a plurality of groups of the third seals, and the liquid outlet of the third sealing circulation system is in communication with the liquid inlet of a plurality of groups of the third seals.

[0014] In some embodiments, the liquid storage unit comprises a water tank, the water tank is connected with the pumping unit through a fifth pipeline, and a filter is arranged on the fifth pipeline.

[0015] In some embodiments, the pumping unit comprises a second circulating pump, two second circulating pumps are arranged, the liquid inlets of the two second circulating pumps are respectively connected with the water tank through two groups of the fifth pipelines, the liquid outlets of the two second circulating pumps are sequentially provided with a second check valve and a fourth ball valve, and the liquid outlets of the two second circulating pumps are respectively connected with each group of the liquid supplementing units through a sixth pipeline, the sixth pipeline is connected with a third valve group, a second pressure transmitter, and a second accumulator.

[0016] In some embodiments, each of the liquid supplement units comprises at least one pressure relief branch structure, the pressure relief branch structure comprises a first pressure relief branch, a pressure relief pipeline, a pressure detection pipeline, a fifth ball valve, an automatic regulating valve, a third check valve, a sixth ball valve, a seventh ball valve, a first pressure relief valve, a fourth valve group and a second pressure gauge, the control system comprises a controller and a control chamber, the first pressure relief branch is connected to the sealed circulation system and the pumping unit respectively, the first pressure relief branch is sequentially provided with the fifth ball valve, the automatic regulating valve, the pressure relief pipeline, the sixth ball valve, the pressure detection pipeline and the third check valve in the direction of the barrier fluid flow, the automatic regulating valve has a nitrogen charging port, the automatic regulating valve of each of the liquid supplement units is connected to the control chamber through the controller, and the automatic regulating valve is adjusted through the control chamber and the controller, so that the output pressure of the first pressure relief branch is controlled; the pressure relief pipeline is provided with the seventh ball valve and the first pressure relief valve; the pressure detection pipeline is provided with the fourth valve group and the second pressure gauge.

[0017] In some embodiments, the water tank is provided with a liquid injection port, a vent port and a breathing filter, the liquid injection port and the vent port are respectively provided with an eighth ball valve and a ninth ball valve; the water tank is further connected to a second flow transmitter through a tenth ball valve; the automatic liquid supplement system further comprises a safety pipeline, an eighth pipeline, a safety valve and a fourth needle valve, one end of the safety pipeline is connected to the sixth pipeline and the water tank, the safety valve is installed on the safety pipeline, the eighth pipeline is connected to the other end of the sixth pipeline and the water tank, and the fourth needle valve is installed on the eighth pipeline.

[0018] Compared with the prior art, the mechanical seal system for the automatic liquid supplement pump provided by the application comprises a plurality of groups of mechanical seals, a plurality of groups of sealed circulation systems and an automatic liquid supplement system, the multi-stage seals of each group of mechanical seals are arranged on the multi-stage pumps of the series pump group, the sealed circulation system provides the barrier fluid to the multi-stage seals and circulates and exchanges heat of the barrier fluid in the mechanical seals, so that a protective film is formed between the dynamic ring and the static ring of the pump, which is used for preventing the leakage of the transported medium and preventing the external air or impurities from entering the sealing area; the automatic liquid supplement system comprises a liquid storage unit, a pumping unit and a liquid supplement unit, the pumping unit maintains the pipeline pressure in the liquid supplement unit, which ensures the normal flow of the barrier fluid and is conducive to the stable operation of the liquid supplement unit; a plurality of groups of liquid supplement units are connected to the groups of sealed circulation systems and are controlled by the control system according to the preset logic, which can output gradient pressure in parallel according to different terminal pressure requirements, and solves the self-balancing problem of the pressure difference between the cavity of each unit and the sealing barrier fluid during the operation of the series pump group. The system can effectively manage the sealing cavity pressure gradient during the operation of the series pump group, and improves the overall efficiency and reliability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 is a structural schematic diagram of a mechanical seal system for an automatic liquid supplement pump according to an embodiment of the present application;

[0020] Fig. 2 is a hierarchical connection structural schematic diagram of the mechanical seal system for the automatic liquid supplement pump according to an embodiment of the present application;

[0021] Fig. 3 is a structural schematic diagram of a seal circulation system in the mechanical seal system for the automatic liquid supplement pump according to an embodiment of the present application;

[0022] Fig. 4 is a structural schematic diagram of an automatic liquid supplement system in the mechanical seal system for the automatic liquid supplement pump according to an embodiment of the present application;

[0023] Fig. 5 is a structural schematic diagram of a liquid supplement unit of the automatic liquid supplement system in the mechanical seal system for the automatic liquid supplement pump according to an embodiment of the present application;

[0024] Fig. 6 is a three-dimensional structural schematic diagram of the seal circulation system in the mechanical seal system for the automatic liquid supplement pump according to an embodiment of the present application;

[0025] Fig. 7 is a three-dimensional structural schematic diagram of the automatic liquid supplement system in the mechanical seal system for the automatic liquid supplement pump according to an embodiment of the present application.

[0026] Reference signs: 1, mechanical seal; 2, seal circulation system; 21, heat exchanger; 22, first energy accumulator; 23, first circulation pump; 24, first valve group; 25, first temperature transmitter; 26, sight glass; 27, first pressure gauge; 28, first pressure transmitter; 29, second valve group; 210, first ball valve; 211, first needle valve; 212, first flow transmitter; 213, second ball valve; 214, gate valve; 215, quick coupling; 216, first check valve; 217, second needle valve; 201, first pipeline; 202, second pipeline; 203, third pipeline; 204, first liquid inlet pipeline; 205, second liquid inlet pipeline; 206, fourth pipeline; 3, automatic liquid supplement system; 31, water tank; 32, filter; 33, second circulation pump; 34, second check valve; 35, fourth ball valve; 36, third valve group; 37, second pressure transmitter; 38, second energy accumulator; 39, fifth ball valve; 310, automatic regulating valve; 311, third check valve; 312, sixth ball valve; 313, seventh ball valve; 314, first pressure relief valve; 315, fourth valve group; 316, second pressure gauge; 317, second pressure relief valve; 318, eighth ball valve; 319, ninth ball valve; 320, breathing filter; 321, tenth ball valve; 322, second flow transmitter; 323, safety valve; 324, fourth needle valve; 301, fifth pipeline; 302, sixth pipeline; 303, first pressure reduction branch; 304, pressure relief pipeline; 305, pressure detection pipeline; 306, seventh pipeline; 307, safety pipeline; 308, eighth pipeline. DETAILED DESCRIPTION

[0027] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0028] In order to solve the technical problem that the liquid supplementing system is difficult to apply to the multi-stage pump system, the present application provides an automatic liquid supplementing pump mechanical seal system, which can output gradientized pressure in parallel according to different terminal pressure requirements, can effectively manage the sealing cavity pressure gradient in the operation of the series pump group, and improves the overall efficiency and reliability of the system.

[0029] Please refer to FIGS. 1-7, the automatic liquid supplementing pump mechanical seal system comprises: a plurality of groups of mechanical seals 1, a plurality of groups of sealing circulation systems 2, an automatic liquid supplementing system 3 and a control system, each group of the mechanical seals 1 corresponds to a plurality of series pump groups, each group of the mechanical seals 1 comprises a multi-stage seal, and the multi-stage seal is arranged on a multi-stage pump of the series pump group; the liquid inlet and the liquid outlet of each group of the sealing circulation systems 2 are respectively connected to the liquid outlet and the liquid inlet of the multi-stage seal, and are used for circulating and delivering heat exchange of the barrier liquid in the mechanical seal 1; the automatic liquid supplementing system 3 comprises a liquid storage unit, a pumping unit and a plurality of groups of liquid supplementing units connected to each group of the sealing circulation systems 2, the liquid outlet of the liquid storage unit is connected to each group of the liquid supplementing units through the pumping unit, so as to maintain the pipeline pressure in the liquid supplementing unit through the pumping unit; and the control system is connected to the liquid supplementing unit, so as to control the liquid supplementing unit to supplement the set pressure to the corresponding sealing circulation system 2 according to the required pressure of each stage of the mechanical seal 1.

[0030] In the scheme, each group of multi-stage seals 1 is arranged on the multi-stage pumps of the series pump group, and the sealing circulating system 2 provides the multi-stage seal with isolation liquid, and circulates and exchanges heat of the isolation liquid in the mechanical seal 1, so that a protective film is formed between the dynamic ring and the static ring of the pump, which is used to prevent the leakage of the transported medium and prevent the outside air or impurities from entering the sealing area. The automatic liquid supplementing system 3 includes a liquid storage unit, a pumping unit and a liquid supplementing unit, the pumping unit maintains the pipeline pressure in the liquid supplementing unit, which ensures the normal flow of the isolation liquid and is beneficial to the stable operation of the liquid supplementing unit; in the multi-stage series pump group, the pressure of the medium in the pump gradually increases, so that the seal of each stage of the pump needs to gradually increase the pressure to balance the pressure difference between the stages of the pump, and the scheme connects each group of sealing circulating systems 2 with a plurality of liquid supplementing units, and controls the system according to the preset logic control through real-time monitoring of the operating state by the remote signal transmission device, so that the system can effectively manage the pressure gradient of the sealing cavity in the operation of the series pump group, and the overall efficiency and reliability of the system are improved.

[0031] It should be noted that in the embodiment, the sealing pressure of each stage of pump should be slightly higher than the pressure of the internal medium, so that as the pressure in the multi-stage pump of the series pump group gradually increases, the pressure value provided by the liquid supplementing unit to the sealing circulating system 2 corresponding to the multi-stage pump gradually increases. When the sealing pressure is slightly higher than the pressure of the sealed medium, a pressure difference can be formed, which can prevent the sealed medium from leaking from the sealing surface. The pressure barrier formed at the sealing surface helps to maintain the integrity of the seal.

[0032] Please refer to FIG. 1 and FIG. 2, the branch pressure requirement is associated with the pump cavity pressure, and the pump cavity pressure is associated with the pump outlet pressure, for example, in a three-stage series, the series pump pressure gradually increases from the first stage to the third stage, in order to ensure that the pressure between the sealing surfaces is moderate, the pressure value provided by the corresponding pressure reducing branch should be adaptively increased. For convenience of description, in the following embodiments, the multi-stage pumps of each group of series pump groups are defined as first-stage pump, second-stage pump and third-stage pump respectively; each group of multi-stage seals and sealing circulating systems 2 are correspondingly provided with three stages, and the multi-stage seals are defined as first-stage seal, second-stage seal and third-stage seal respectively, and a plurality of groups of sealing circulating systems 2 are defined as first-stage sealing circulating system, second-stage sealing circulating system and third-stage sealing circulating system.

[0033] Wherein, several groups of the primary seals are respectively installed on several groups of the primary pumps, several groups of the secondary seals are respectively installed on several groups of the secondary pumps, and several groups of the tertiary seals are respectively installed on several groups of the tertiary pumps; the liquid inlet of the primary seal circulation system is in communication with the liquid outlets of several groups of the primary seals, and the liquid outlet thereof is in communication with the liquid inlets of several groups of the primary seals; the liquid inlet of the secondary seal circulation system is in communication with the liquid outlets of several groups of the secondary seals, and the liquid outlet thereof is in communication with the liquid inlets of several groups of the secondary seals; and the liquid inlet of the tertiary seal circulation system is in communication with the liquid outlets of several groups of the tertiary seals, and the liquid outlet thereof is in communication with the liquid inlets of several groups of the tertiary seals. The three liquid supplement units supplement pressure to the multi-stage seal circulation system 2 respectively, so that the gradient pressure is output in parallel, thereby ensuring that the pressure at the mechanical seal 1 of each pump can prevent fluid leakage and avoid damage to the seal due to excessively high pressure, and ensuring the overall stability of the pump group.

[0034] Please refer to FIG. 1, FIG. 3 and FIG. 6, the seal circulation system 2 forms an external circulation loop, so that the barrier liquid circulates between the pump and the external circulation loop to achieve better cooling and lubrication effect. In the embodiment, each group of the seal circulation system 2 comprises a heat exchanger 21, a first accumulator 22 and a first circulating pump 23. The liquid inlet of the heat exchanger 21 is connected to the liquid outlet of the mechanical seal 1 through a first pipeline 201, the liquid outlet of the heat exchanger 21 is connected to the liquid inlet of the mechanical seal 1 through a second pipeline 202, and the heat exchanger 21 is further provided with a cooling water inlet and a cooling water outlet for the barrier liquid to enter and exit, so as to circulate and supplement cooling water into the heat exchanger 21 through the cooling water inlet and the cooling water outlet, and realize heat exchange and cooling of the barrier liquid inside the heat exchanger 21. Wherein, a spiral pipe is arranged in the heat exchanger 21, and the two ends of the spiral pipe are connected to the liquid inlet and the liquid outlet of the heat exchanger 21 respectively, so as to realize circulation and heat exchange of the barrier liquid, and ensure that the barrier liquid in the seal circulation system 2 is in a pressure environment.

[0035] The first accumulator 22 is connected to the second pipeline 202 through a third pipeline 203, and the other end of the third pipeline 203 is connected to the liquid supplement unit through a first liquid inlet pipeline 204. The first circulating pump 23 is installed on the second pipeline 202, and is used to provide driving force for the circulation of the barrier liquid between the heat exchanger 21 and the mechanical seal 1. In the implementation, the first circulating pump 23 provides driving force to drive the barrier liquid to circulate between the mechanical seal 1, the first pipeline 201, the heat exchanger 21 and the second pipeline 202, and the barrier liquid for pressure supplement is supplemented through the first liquid inlet pipeline 204 and the third pipeline 203.

[0036] In FIG. 3, A is an exhaust port, B is the flow direction of the barrier fluid from the seal, C is the flow direction of the barrier fluid to the seal, D is a cooling water inlet, E is a cooling water outlet, F is a vent port, G is a liquid supplement unit interface, H is a nitrogen gas charging port, and I is a liquid supplement port.

[0037] In order to optimize the pipeline structure of the sealing circulation system 2, further, in some possible embodiments, the sealing circulation system 2 further comprises a first valve group 24, a first temperature transmitter 25, a sight glass 26, a first pressure gauge 27, a first pressure transmitter 28, a second valve group 29, a first ball valve 210, a first needle valve 211, a first flow transmitter 212, a second ball valve 213, and a second needle valve, and the like, the first valve group 24, the first temperature transmitter 25, and the sight glass 26 are sequentially installed on the first pipeline 201, the first pressure gauge 27 is connected with the first valve group 24; the first pressure transmitter 28 is connected with the third pipeline 203 through the second valve group 29; the first ball valve 210 is connected with the third pipeline 203; the first needle valve 211, the first flow transmitter 212, and the second ball valve 213 are sequentially installed on the first liquid inlet pipeline 204; the fourth pipeline 206 connected with the liquid inlet and outlet of the first liquid inlet pipeline 204 is also installed on the first liquid inlet pipeline 204, and the second needle valve 217 is installed on the fourth pipeline 206. The first flow transmitter 212 can record the barrier fluid flow, and through the flow change trend, the daily leakage of the seal can be inferred, and thus the advance prediction can be achieved.

[0038] It can be understood that the pressure supplement of the pipeline is not limited to only supplementing through one pipeline, therefore, in the embodiment, a plurality of liquid inlet pipelines can be further provided to jointly supplement the pressure of the barrier fluid, preferably, in the embodiment, the sealing circulation system 2 further comprises a second liquid inlet pipeline 205, a gate valve 214, a quick connector 215, and a first check valve 216, the second liquid inlet pipeline 205 is connected with the third pipeline 203 in parallel with the first liquid inlet pipeline 204, the third pipeline 203 is sequentially provided with the quick connector 215, the gate valve 214, and the first check valve 216 along the flow direction of the barrier fluid, and the pressure of the barrier fluid in the circulation pipeline can be supplemented through the first liquid inlet pipeline 204 and the second liquid inlet pipeline 205 jointly or independently.

[0039] The pressure of the sealing liquid in the sealing circulation system 2 is maintained by the first accumulator 22, which is preferably a bladder accumulator, so that the pressurized gas and the sealing liquid are prevented from contacting each other, thereby avoiding the absorption of the pressurized gas by the sealing liquid and enabling the sealing to be used in high-pressure operating conditions. The accumulator should be initially filled with the pressurized gas and then filled with the sealing liquid, and the accumulator is brought to the operating pressure by compressing the bladder with the sealing liquid. The initial filling pressure of the accumulator should be slightly higher than the required pressure, so that when the sealing leaks, the pressure of the accumulator drops to the specified minimum pressure. At this time, the system should be refilled with the sealing liquid to maximize the working volume of the sealing liquid, and the performance of the sealing is monitored by detecting the pressure drop.

[0040] The flushing scheme can only be effectively implemented when there is no gas or bubbles in the pipeline and the sealing cooler, and the gas in the system should be discharged before starting. The sealing circulation system 2 is provided with real-time monitoring and early warning of pressure, temperature, flow rate, etc., and the control system will display an alarm at the first time when a large leakage occurs in the sealing, at which time the system is automatically switched to the liquid supplement branch, and a large amount of high-pressure flushing liquid is directly injected into the sealing cavity to block the leakage point of the ore pulp, prevent external air or other substances from entering the pump, and also prevent the ore pulp from leaking out.

[0041] Referring to FIGS. 1, 4, 5 and 7, in the embodiment, the liquid storage unit includes a water tank 31, the pumping unit includes a second circulating pump 33, each set of the liquid supplement unit includes at least one pressure relief branch structure, the pressure relief branch structure includes a first pressure relief branch 303, a pressure relief pipeline 304, a pressure detection pipeline 305, a fifth ball valve 39, an automatic regulating valve 310, a third check valve 311, a sixth ball valve 312, a seventh ball valve 313, a first pressure relief valve 314, a fourth valve group 315 and a second pressure gauge 316. The control system includes a controller and a control room.

[0042] Specifically, the second circulating pump 33 is provided with two, the liquid inlets of the two second circulating pumps 33 are connected to the water tank 31 through two groups of fifth pipelines 301, one end of the fifth pipeline 301 provided in the water tank 31 is provided with a filter 32, the liquid outlets of the two second circulating pumps 33 are sequentially provided with a second check valve 34 and a fourth ball valve 35, and are connected to the first pressure relief branch 303 of each set of the liquid supplement unit through a sixth pipeline 302, and the sixth pipeline 302 is connected with a third valve group 36, a second pressure transmitter 37 and a second accumulator 38.

[0043] The first pressure reducing branch 303 is connected with the sixth pipeline 302 and the liquid inlet pipeline of the sealing circulation system 2 respectively, and the fifth ball valve 39, the automatic regulating valve 310, the pressure relief pipeline 304, the sixth ball valve 312, the pressure detecting pipeline 305 and the third check valve 311 are sequentially arranged on the first pressure reducing branch 303 along the flowing direction of the isolation liquid, the automatic regulating valve 310 has a nitrogen charging port, the automatic regulating valve 310 of each group of the liquid supplementing unit is connected with the control chamber through the controller, and the automatic regulating valve 310 is adjusted through the control chamber and the controller, so that the output pressure of the first pressure reducing branch 303 is controlled; the seventh ball valve 313 and the first pressure relief valve 314 are arranged on the pressure relief pipeline 304; the fourth valve group 315 and the second pressure gauge 316 are arranged on the pressure detecting pipeline 305.

[0044] In order to ensure the normal operation of the automatic liquid supplementing system 3, a suitable pressure level must be maintained, preferably, the pressure is set to 4.0 MPa, the water tank 31 stores the isolation liquid, and the total pressure is maintained at 4.0 MPa by supplying liquid to the sealing circulation system 2 through two second circulating pumps 33, when the first pressure transmitter 28 detects that the pressure is lower than a certain set value due to the leakage of the mechanical seal, the signal is transmitted to the PLC control system, the second circulating pump 33 is automatically started, and the pump is stopped when the pressure reaches 4.0 MPa. The total pressure is output in parallel to multiple branches with different pressures, and each branch (G1-G10) corresponds to a PCV automatic regulating valve 310, which is connected with the PLC control system chamber through a 24V electric signal, the actuator of the valve is pneumatic, when the pressure needs to be changed, the control system chamber inputs the electric signal, and then converts it into an analog signal to transmit to the pneumatic actuator of the PCV valve, the actuator pushes the valve rod to produce displacement, so as to realize the pressure before and after the automatic regulating valve 310.

[0045] The isolation liquid in the water tank 31 increases the pressure of the liquid supplementing pipeline to a certain set value (4 MPa) through the second circulating pump 33, the pump stops working when the pressure reaches 4 MPa, when the pressure is lower than a certain set value (3.8 MPa), the single pump starts to supplement the pressure to the set value (4 MPa), if the mechanical seal leaks a lot and the pressure is lower than a certain set value, the double pump starts to supplement the liquid, and at the same time, the control system chamber detects the signal, which proves that the mechanical seal 1 has failed and needs to be replaced.

[0046] When the automatic regulating valve 310 adjusts the pressure, it mainly controls the flow of fluid by changing the opening of the valve, thereby achieving the purpose of adjusting the downstream pressure. The specific principle of the pneumatic automatic regulating valve 310 adjusting the pressure is as follows: the automatic regulating valve 310 receives a gas pressure signal from the control system (such as a PID controller). This signal is based on the comparison between the actual pressure value measured by the sensor and the preset pressure set value. Inside the pneumatic actuator of the automatic regulating valve 310, there is a diaphragm or piston that will displace when it receives the gas pressure signal. The displacement of the diaphragm or piston is transmitted to the valve stem through a connecting rod or other transmission mechanism, which in turn drives the valve core (or valve flap) to move up and down. The position change of the valve core determines the size of the valve opening. If you need to increase the pressure, you need to reduce the valve opening; if you need to reduce the pressure, you need to increase the valve opening. The system usually also includes a position feedback device that can detect the actual position of the valve core and transmit information back to the controller for closed-loop control to ensure that the actual pressure matches the set value.

[0047] Preferably, in this application, the number of pressure reducing branch structures in each group of the liquid supplementing unit is not limited, and the number of pressure reducing branch structures connected by the corresponding sealing circulating system 2 can be increased in sequence according to the increase of the medium pressure in the primary pump to the tertiary pump; for example, the primary sealing circulating system is connected with two pressure reducing branch structures, the secondary sealing circulating system is connected with three pressure reducing branch structures, and the tertiary sealing circulating system is connected with five pressure reducing branch structures.

[0048] Further, in some embodiments, the water tank 31 is provided with a liquid filling port, a vent port and a breathing filter 320, as shown in FIG. 4, a is the liquid filling port, and b is the vent port. The eighth ball valve 318 and the ninth ball valve 319 are respectively installed on the liquid filling port and the vent port, so that the isolation liquid can be supplemented into the water tank 31 through the liquid filling port, and the isolation liquid can be discharged through the vent port to clean the water tank 31. The water tank 31 is also connected with the second flow transmitter 322 through the tenth ball valve 321. The seventh pipeline 306 is provided on the first pressure reducing branch 303 in parallel with the automatic regulating valve 310, and the second pressure relief valve 317 is provided on the seventh pipeline 306.

[0049] Still further, in some embodiments, the automatic liquid supplementing system 3 further comprises a safety pipeline 307, an eighth pipeline 308, a safety valve 323 and a fourth needle valve 324. The safety pipeline 307 is connected with one end of the sixth pipeline 302 and the water tank 31 respectively, and the safety valve 323 is installed on the safety pipeline 307. The eighth pipeline 308 is connected with the other end of the sixth pipeline 302 and the water tank 31, and the fourth needle valve 324 is installed on the eighth pipeline 308. When the pipeline pressure of the automatic liquid supplementing system 3 is greater than the set value, the pressure can be released through the installation pipeline.

[0050] It should be noted that in this scheme, the valves and detection components installed on each pipeline are not limited, and valves, detection components and control structures can be installed on the main liquid supply pipeline and branch pipeline as needed.

[0051] The application sets several groups of mechanical seals 1, several groups of sealing circulation systems 2 and an automatic liquid supplementing system 3. The multi-stage seals of each group of mechanical seals 1 are arranged on the multi-stage pumps of the tandem pump set. The sealing circulation system 2 provides isolation liquid to the multi-stage seals and circulates and exchanges heat of the isolation liquid in the mechanical seal 1, so as to form a protective film between the dynamic ring and the static ring of the pump, which is used to prevent the leakage of the transported medium and prevent the outside air or impurities from entering the sealing area. The automatic liquid supplementing system 3 includes a liquid storage unit, a pumping unit and a liquid supplementing unit. The pumping unit maintains the pipeline pressure in the liquid supplementing unit, so as to ensure the normal flow of the isolation liquid and facilitate the stable operation of the liquid supplementing unit. The several groups of liquid supplementing units are connected to the several groups of sealing circulation systems 2 and are controlled by the preset logic of the control system. The parallel output of the gradient pressure can meet different terminal pressure requirements and solve the self-balancing problem of the pressure difference between the cavity of each unit and the sealing liquid in the operation of the tandem pump set. The system can effectively manage the pressure gradient of the sealing cavity in the operation of the tandem pump set, and the overall efficiency and reliability of the system are improved.

[0052] The sealing circulation system 2 is provided with real-time monitoring and early warning of pressure, temperature, flow and the like. Once a large leakage occurs in the seal, the control system will display an alarm at the first time, and then automatically switch to the liquid supplementing branch to inject a large amount of high-pressure flushing liquid into the sealing cavity to plug the leakage point of the ore pulp and prevent the ore pulp from flowing out to cause harm to people.

[0053] During operation, the inlet and outlet pressures of each stage pump need to be accurately measured, and these data need to be monitored in real time to understand the pressure distribution of the system. According to the monitored data, the pressure to be supplemented is determined to ensure that the sealing pressure is always higher than the medium pressure by a certain value and ensure the stability of the system. The isolation liquid in the sealing circulation system 2 is transported by the second circulating pump 33 (gear pump), heat exchange is performed in the heat exchanger 21, and the accumulator stabilizes the pressure, so that the pressure difference between the cavity of each mechanical seal 1 and the pump cavity is kept at 0.3 MPa self-circulation (as the pump continues to operate, the isolation liquid between the sealing surfaces gradually flows away, the pressure of the sealing circulation system 2 gradually decreases, and when it is lower than a certain set value, the PCV automatic regulating valve 310 of the liquid supplementing unit is opened to supplement the pressure of the sealing circulation system 2, and when the set value is reached, the valve is automatically closed).

[0054] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper" and "lower" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise expressly specified and limited, the terms "mounting", "connection" and "connection" should be interpreted broadly, for example, it can be a fixed connection, or a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0055] It should be noted that in the present application, relational terms such as "first" and "second" and the like are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0056] The specific embodiments of the present application described above do not constitute a limitation on the scope of protection of the present application. Any various other corresponding changes and modifications made in accordance with the technical concept of the present application should be included within the scope of protection of the claims of the present application.

Claims

1. A mechanical seal system for an automatic fluid replacement pump, characterized by, The application relates to a mechanical seal system for a series pump group. The mechanical seal system comprises a plurality of groups of mechanical seals, each group of mechanical seals corresponding to a plurality of groups of series pump groups, each group of mechanical seals comprising a plurality of levels of seals arranged on a plurality of levels of pumps of the series pump group; a plurality of groups of seal circulation systems, the inlet and outlet of each group of seal circulation systems being connected to the outlet and inlet of the corresponding level of seal, and used for circulating and heat-exchanging the barrier liquid in the mechanical seal; an automatic liquid supplementing system, which comprises a liquid storage unit, a pumping unit and a plurality of groups of liquid supplementing units connected to the groups of seal circulation systems, the outlet of the liquid storage unit being connected to the groups of liquid supplementing units through the pumping unit, so that the pipeline pressure in the liquid supplementing unit is maintained through the pumping unit; and a control system connected to the liquid supplementing units, which controls the liquid supplementing units to supplement the corresponding seal circulation system with a set pressure according to the pressure required by each level of seal in the mechanical seal.

2. The mechanical seal system for an automatic compounder pump according to claim 1, wherein With the gradual increase of the pressure in the plurality of levels of pumps of the series pump group, the pressure value provided by the liquid supplementing unit to the seal circulation system corresponding to the plurality of levels of pumps gradually increases.

3. The mechanical seal system for an automatic compounder pump according to claim 1, wherein Each group of seal circulation systems comprises a heat exchanger, a first accumulator and a first circulating pump, the inlet of the heat exchanger being connected to the outlet of the mechanical seal through a first pipeline, the outlet of the heat exchanger being connected to the inlet of the mechanical seal through a second pipeline, and the heat exchanger being further provided with a cooling water inlet and outlet for the cooling liquid; the first accumulator being connected to the second pipeline through a third pipeline, the other end of the third pipeline being connected to the liquid supplementing unit through a first liquid inlet pipeline; the first circulating pump being installed on the second pipeline and used for providing driving force for the circulation of the cooling liquid between the heat exchanger and the mechanical seal.

4. The mechanical seal system for an automatic compounder pump according to claim 3, wherein Each group of seal circulation systems further comprises a second liquid inlet pipeline, a gate valve, a quick connector and a first check valve, the second liquid inlet pipeline being connected to the third pipeline in parallel with the first liquid inlet pipeline, the third pipeline being sequentially provided with the quick connector, the gate valve and the first check valve along the flow direction of the cooling liquid.

5. The mechanical seal system for an automatic compounder pump according to claim 4, wherein Each group of seal circulation systems further comprises a first valve group, a first temperature transmitter, a sight glass, a first pressure gauge, a first pressure transmitter, a second valve group, a first ball valve, a first needle valve, a first flow transmitter, a second ball valve and a second needle valve, the first valve group, the first temperature transmitter and the sight glass being sequentially arranged on the first pipeline, and the first pressure gauge being connected to the first valve group; the first pressure transmitter being connected to the third pipeline through the second valve group; the first ball valve being connected to the third pipeline; the first needle valve, the first flow transmitter and the second ball valve being sequentially connected to the first liquid inlet pipeline; the first liquid inlet pipeline being further provided with a fourth pipeline connected to the inlet and outlet of the first liquid inlet pipeline, and the second needle valve being arranged on the fourth pipeline.

6. The mechanical seal system for an automatic compounder pump of claim 1, wherein, Each group of series pump groups is provided with three levels, i.e. a first level pump, a second level pump and a third level pump. Each of the multi-stage seals comprises a first-stage seal, a second-stage seal and a third-stage seal, a plurality of the first-stage seals are respectively installed on a plurality of the first-stage pumps, a plurality of the second-stage seals are respectively installed on a plurality of the second-stage pumps, and a plurality of the third-stage seals are respectively installed on a plurality of the third-stage pumps; A plurality of the seal circulation systems respectively comprise a first-stage seal circulation system, a second-stage seal circulation system and a third-stage seal circulation system, the inlet of the first-stage seal circulation system is communicated with the outlet of a plurality of the first-stage seals, the outlet of the first-stage seal circulation system is communicated with the inlet of a plurality of the first-stage seals, the inlet of the second-stage seal circulation system is communicated with the outlet of a plurality of the second-stage seals, the outlet of the second-stage seal circulation system is communicated with the inlet of a plurality of the second-stage seals, the inlet of the third-stage seal circulation system is communicated with the outlet of a plurality of the third-stage seals, and the outlet of the third-stage seal circulation system is communicated with the inlet of a plurality of the third-stage seals.

7. The mechanical seal system for an automatic compounder pump according to claim 1, wherein The liquid storage unit comprises a water tank, and the water tank is connected with the pumping unit through a fifth pipeline, and a filter is arranged on the fifth pipeline.

8. The mechanical seal system for an automatic compounder pump according to claim 7, wherein The pumping unit comprises two second circulation pumps, the inlets of the two second circulation pumps are respectively connected with the water tank through two groups of the fifth pipelines, the outlets of the two second circulation pumps are respectively provided with a second check valve and a fourth ball valve, and the outlets of the two second circulation pumps are respectively connected with each group of the liquid supplement units through a sixth pipeline, and the sixth pipeline is connected with a third valve group, a second pressure transmitter and a second accumulator.

9. The mechanical seal system for an automatic compounder pump according to claim 8, wherein Each of the liquid supplement units comprises at least one pressure reduction branch structure, the pressure reduction branch structure comprises a first pressure reduction branch, a pressure relief pipeline, a pressure detection pipeline, a fifth ball valve, an automatic regulating valve, a third check valve, a sixth ball valve, a seventh ball valve, a first pressure relief valve, a fourth valve group and a second pressure gauge, and the control system comprises a controller and a control chamber. The first pressure reduction branch is connected with the seal circulation system and the pumping unit, the first pressure reduction branch is sequentially provided with the fifth ball valve, the automatic regulating valve, the pressure relief pipeline, the sixth ball valve, the pressure detection pipeline and the third check valve along the flowing direction of the barrier fluid, the automatic regulating valve is provided with a nitrogen charging port, the automatic regulating valve of each of the liquid supplement units is connected with the control chamber through the controller, and the automatic regulating valve is adjusted through the control chamber and the controller, so that the output pressure of the first pressure reduction branch is controlled. The pressure relief pipeline is provided with the seventh ball valve and the first pressure relief valve. The pressure detection pipeline is provided with the fourth valve group and the second pressure gauge.

10. The mechanical seal system for an automatic compounder pump according to claim 9, wherein, The water tank is provided with a liquid injection port, a liquid emptying port and a breathing filter, the liquid injection port and the liquid emptying port are respectively provided with an eighth ball valve and a ninth ball valve, and the water tank is further connected with a second flow transmitter through a tenth ball valve. The automatic liquid supplement system further comprises a safety pipeline, an eighth pipeline, a safety valve and a fourth needle valve, the safety pipeline is connected with one end of the sixth pipeline and the water tank, the safety valve is arranged on the safety pipeline, the eighth pipeline is connected with the other end of the sixth pipeline and the water tank, and the fourth needle valve is arranged on the eighth pipeline.

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