High-pressure propylene pump sealing liquid recycling system

Abstract

The utility model discloses a high-pressure propylene pump sealing liquid recycling system which comprises a high-pressure propylene pump, a first pipeline, a root valve, a sight glass, a filter, a second pipeline, a sampling valve, a main body oil collecting groove, a third pipeline, a pneumatic diaphragm pump, a fourth pipeline, a switch valve, a waste liquid discharging valve and a sealing liquid tank. The discharge cavity of the mechanical seal on the high-pressure propylene pump, the first pipe, the filter, the second pipeline, the main body oil collecting tank, the third pipeline, the pneumatic diaphragm pump, the fourth pipeline, the sealing liquid tank and the discharge cavity of the mechanical seal on the high-pressure propylene pump are communicated in sequence to form circulation; the root valve and the sight glass are arranged on the first pipeline; the sampling valve is arranged on the second pipeline; a liquid level meter is arranged on the main body oil collecting tank; the switch valve and the waste liquid discharge valve are arranged on the fourth pipeline, and the waste liquid discharge valve is located on the downstream of the switch valve. By adopting the closed system, the sealing liquid is filtered, collected and replenished, so that the frequency of replacing the mechanical seal is reduced, the operation risk and supervision are reduced, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to a high-pressure propylene pump sealing liquid recovery circulation system, belonging to the technical field of petrochemical equipment. Background Art

[0002] At present, the propylene high-speed pump of the domestic PO / MTBE unit is a 2-stage high-speed centrifugal pump of the HMP-3000 series of the American SUNDYNE company. The impeller adopts an open impeller, and the first-stage impeller is equipped with an integral inducer. The pump seal adopts the flushing method of PLAN11+54, the pump outlet pressure reaches 175 kg, and the speed of this high-pressure propylene pump is increased to 15600rpm through the gear box, and the pressure of the mechanical seal isolation fluid reaches 5.5MPa or even above. The pressure difference with the atmospheric environment is too high. Therefore, the seal isolation fluid of this type of pump will leak out from the mechanical seal continuously, causing the liquid level of the sealing liquid system to drop. The existing method for dealing with leakage of mechanical seal of high-pressure propylene pump is: directly discharge the leaked sealing isolation fluid into the dirty oil system, or manually collect it and inject it into the sealing liquid tank under manual pressure, or directly replace the mechanical seal. The above measures have the following shortcomings: 1. The leaked sealing isolation fluid is directly discharged into the dirty oil system, causing material loss and increased cost of secondary treatment; 2. In the process of manually collecting and recovering the leaked sealing fluid, the sealing fluid is very likely to be contaminated, thereby affecting the sealing, lubrication and cleaning effects; 3. Frequent replacement of seals increases costs, increases the risk of on-site operations, and increases the labor intensity of maintenance personnel. Utility Model Content

[0003] The utility model provides a high-pressure propylene pump sealing liquid recovery and circulation system, which adopts a closed filtering, collecting and replenishing method to automatically recover and reuse expensive sealing liquid, reduce the frequency of replacing mechanical seals, and reduce the risks of direct operation links; improve the utilization rate of sealing liquid, reduce the labor intensity of on-site maintenance, reduce the cost of sewage treatment, make impossible collection feasible, and improve the on-site appearance.

[0004] In order to solve the above technical problems, the technical solutions adopted by the present utility model are as follows:

[0005] A high-pressure propylene pump sealing liquid recovery circulation system, comprising a high-pressure propylene pump, a first pipeline, a root valve, a sight glass, a filter, a second pipeline, a sampling valve, a main body oil collecting tank, a third pipeline, a pneumatic diaphragm pump, a fourth pipeline, a switch valve, a waste liquid discharge valve and a sealing liquid tank;

[0006] One end of the first pipeline is connected to the external discharge cavity of the mechanical seal on the high-pressure propylene pump, and the other end is connected to the filter inlet; the root valve and the sight glass are arranged on the first pipeline; one end of the second pipeline is connected to the filter outlet, and the other end is connected to the top of the main body oil collection tank, and the sampling valve is arranged on the second pipeline; a liquid level gauge is arranged on the main body oil collection tank;

[0007] One end of the third pipeline is connected to the bottom of the side wall of the main body oil collecting tank, and the other end is connected to the inlet of the pneumatic diaphragm pump. One end of the fourth pipeline is connected to the outlet of the pneumatic diaphragm pump, and the other end is connected to the sealing liquid tank; the switch valve and the waste liquid discharge valve are arranged at one end of the fourth pipeline connected to the outlet of the pneumatic diaphragm pump, and the waste liquid discharge valve is located downstream of the switch valve; the sealing liquid tank is circularly connected to the discharge cavity of the mechanical seal on the high-pressure propylene pump, one in and one out, forming a normal circulation flushing process.

[0008] When in use, the flowing sealing liquid passes through the first pipeline, and then passes through the root valve and the sight glass in turn, and reaches the filter for filtration. The filtered sealing liquid flows into the main oil collecting tank through the second pipeline. When the liquid level meter detects that the liquid level of the sealing liquid in the main oil collecting tank is too high, the switch valve and the pneumatic diaphragm pump are opened, and then the sealing liquid in the main oil collecting tank is injected into the sealing liquid tank under the drive of the pneumatic diaphragm pump. When the liquid level meter detects that the liquid level of the sealing liquid reaches a low level, the switch valve and the pneumatic diaphragm pump are closed. When the sealing liquid sampled by the sampling valve fails to meet the test, it needs to be discharged externally. The pneumatic diaphragm pump and the waste liquid discharge valve are opened to clean the stored liquid in the main oil collecting tank in time.

[0009] The external discharge cavity of the mechanical seal on the above-mentioned high-pressure propylene pump is a built-in component of the high-pressure propylene pump and will not be described in detail.

[0010] The direction of this application from upstream to downstream is consistent with the direction of material flow.

[0011] The above-mentioned device filters the sealing liquid in a closed manner and recycles it, reducing material loss and the cost of secondary processing. At the same time, it will not contaminate the sealing liquid, ensure the sealing effect, reduce the frequency of seal replacement, reduce costs, reduce the risks of direct operation links, and reduce the labor intensity of maintenance personnel.

[0012] The above system is equipped with a sight glass on the first pipeline at the top of the filter to facilitate observation of the leakage of the sealing liquid. If the leakage is linear, the equipment needs to be adjusted; a sampling valve is set on the second pipeline for regular detection of the purity of the isolation liquid; a waste liquid discharge valve is provided downstream of the switch valve for harmlessly disposing of the sealing liquid (sealing liquid in the sealing liquid tank) when the sealing liquid is unqualified.

[0013] In order to facilitate oil replenishment, the above-mentioned high-pressure propylene pump sealing liquid recovery circulation system also includes an oil replenishment valve, which is arranged at one end of the third pipeline connected to the inlet of the pneumatic diaphragm pump for normal oil replenishment. When it is necessary to replenish the sealing liquid tank with sealing liquid, the oil replenishment valve, the switch valve and the pneumatic diaphragm pump are opened to replenish the liquid.

[0014] In order to reduce the number of power equipment, the high-pressure propylene pump, the first pipeline, the filter, the second pipeline and the main body oil collection tank are arranged in sequence from top to bottom. In this way, the sealing liquid, under the action of gravity, flows from top to bottom through the external discharge cavity of the mechanical seal on the high-pressure propylene pump, the first pipeline, the filter and the second pipeline, and then enters the main body oil collection tank.

[0015] In order to ensure the smoothness of the liquid flowing from top to bottom, the first pipeline and the second pipeline are made of stainless steel. The connection between the two ends of the stainless steel pipe and the corresponding components can be welded or connected through a threaded adapter pipe, which is convenient for replacement and maintenance.

[0016] In order to ensure continuous filtration, as one of the specific implementation schemes, the filter includes a first filter and a second filter connected in parallel; the other end of the first pipeline is branched into two paths, respectively connected to the first filter inlet and the second filter inlet, and the first filter inlet and the second filter inlet are both provided with a control valve; one end of the second pipeline is branched into two paths, respectively connected to the first filter outlet and the second filter outlet, and the first filter outlet and the second filter outlet are both provided with a control valve. The two filters can be switched to ensure smooth filtration.

[0017] In order to ensure the continuous filtration, as another specific implementation scheme, the filter is a double filter. The double filter includes two parallel stainless steel filters, and the two filters can be switched to ensure the smooth filtration.

[0018] In order to facilitate automation, the above-mentioned high-pressure propylene pump sealing liquid recovery and circulation system also includes a PLC control box, and the switch valve, pneumatic diaphragm pump and liquid level meter are all connected to the PLC control box and controlled by the PLC control box.

[0019] When using the above-mentioned high-pressure propylene pump sealing liquid recovery circulation system, the flowing sealing liquid passes through the first pipeline, and then passes through the root valve and the sight glass in turn, and reaches the filter for filtration. The filtered sealing liquid flows into the main oil collecting tank through the second pipeline. When the liquid level meter detects that the liquid level of the sealing liquid in the main oil collecting tank is too high, the PLC control box controls the switch valve and the pneumatic diaphragm pump to open, and then the sealing liquid in the main oil collecting tank is injected into the sealing liquid tank under the drive of the pneumatic diaphragm pump. When the liquid level meter detects that the liquid level of the sealing liquid reaches a low level, the PLC control box controls the switch valve and the pneumatic diaphragm pump to close. In addition, when the mechanical seal leaks internally and the sealing liquid tank needs to be supplemented with sealing liquid, the oil replenishing valve, the switch valve and the pneumatic diaphragm pump can be manually controlled for liquid replenishment; when the sealing liquid sampled by the sampling valve is detected to be unqualified, it needs to be discharged externally, and the pneumatic diaphragm pump and the waste liquid discharge valve can be manually opened to clean the stored liquid in the main oil collecting tank in time.

[0020] This application does not make any special improvements to the connection method and control method between the PLC control box and each device. You can refer to the product manual and existing methods, so they will not be repeated here.

[0021] The above-mentioned liquid level gauge is connected to the main oil collecting tank through a flange.

[0022] The above-mentioned propylene high-speed pump is a two-stage high-speed centrifugal pump, and one end of the first pipeline is connected to the secondary sealing rear external discharge cavity of the mechanical seal on the high-pressure propylene pump.

[0023] Control valves, power pumps, instruments, etc. can be installed on each pipeline of this application according to the needs of on-site installation. Each pipeline and the inlet and outlet of each equipment can be connected by plugging, transfer pipe connection, welding, etc.

[0024] The technologies not mentioned in this utility model are all referred to the prior art.

[0025] The utility model high-pressure propylene pump sealing liquid recovery circulation system has the following beneficial effects:

[0026] 1. The high-pressure propylene pump sealing liquid recovery and circulation system adopts a closed filtering, collecting and replenishing method. The recovery process is clean, avoiding discharge into the dirty oil system and saving secondary treatment costs.

[0027] 2. The high-pressure propylene pump sealing liquid recycling system has high sealing liquid recycling efficiency and no pollution, which reduces the loss of sealing liquid and ensures the effect of sealing liquid. It can save more than 500,000 yuan of sealing liquid cost of Purple Crown every year;

[0028] 3. The high-pressure propylene pump sealing liquid recovery and circulation system has a high degree of automation, which makes impossible manual collection possible, reduces the number of mechanical seal replacements, and saves millions of costs each year.

[0029] 4. Reduce the frequency of seal replacement and reduce the risk of direct operation links; improve the utilization rate of sealing liquid, reduce the labor intensity of on-site maintenance, and reduce the cost of sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the structure of the high-pressure propylene pump sealing liquid recovery and circulation system of the utility model;

[0031] In the figure, 1 is a high-pressure propylene pump, a is the first stage, b is the second stage, c is an oil seal, d is a machine seal (mechanical seal), e is a pump outlet, plan11 is a self-flushing process, Plan54 is an external flushing process, 2 is the first pipeline, 3 is a root valve, 4 is a sight glass, 5 is a filter, 6 is the second pipeline, 7 is a sampling valve, 8 is a main oil sump, 9 is the third pipeline, 10 is a pneumatic diaphragm pump, 11 is the fourth pipeline, 12 is a switch valve, 13 is a waste liquid discharge valve, 14 is a sealed liquid tank, 15 is a PLC control box, 16 is a liquid level meter, and 17 is an oil replenishment valve. DETAILED DESCRIPTION

[0032] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments.

[0033] In this application, directional words such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings or in use, and are only for the convenience of describing this application, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0034] Example 1

[0035] like Figure 1 As shown, a high-pressure propylene pump sealing liquid recovery circulation system includes a high-pressure propylene pump, a first pipeline, a root valve, a sight glass, a filter, a second pipeline, a sampling valve, a main body oil collection tank, a third pipeline, a pneumatic diaphragm pump, a fourth pipeline, a switch valve, a waste liquid discharge valve and a sealing liquid tank;

[0036] The propylene high-speed pump is a two-stage high-speed centrifugal pump. One end of the first pipeline is connected to the external discharge cavity of the secondary mechanical seal on the high-pressure propylene pump, and the other end is connected to the filter inlet; the root valve and the sight glass are arranged on the first pipeline, and the root valve is located upstream of the sight glass; one end of the second pipeline is connected to the filter outlet, and the other end is connected to the top of the main body oil collection tank, and the sampling valve is arranged on the second pipeline; a liquid level gauge is arranged on the main body oil collection tank;

[0037] One end of the third pipeline is connected to the bottom of the side wall of the main body oil collecting tank, and the other end is connected to the inlet of the pneumatic diaphragm pump. One end of the fourth pipeline is connected to the outlet of the pneumatic diaphragm pump, and the other end is connected to the sealing liquid tank; the switch valve and the waste liquid discharge valve are arranged at one end of the fourth pipeline connected to the outlet of the pneumatic diaphragm pump, and the waste liquid discharge valve is located downstream of the switch valve; the sealing liquid tank is circularly connected to the external discharge cavity of the two-stage mechanical seal on the high-pressure propylene pump, one in and one out, forming a normal circulation flushing process.

[0038] When in use, the flowing sealing liquid passes through the first pipeline, and then passes through the root valve and the sight glass in turn, and reaches the filter for filtration. The filtered sealing liquid flows into the main oil collecting tank through the second pipeline. When the liquid level meter detects that the liquid level of the sealing liquid in the main oil collecting tank is too high, the switch valve and the pneumatic diaphragm pump are opened, and then the sealing liquid in the main oil collecting tank is injected into the sealing liquid tank under the drive of the pneumatic diaphragm pump. When the liquid level meter detects that the liquid level of the sealing liquid reaches a low level, the switch valve and the pneumatic diaphragm pump are closed. When the sealing liquid sampled by the sampling valve is detected to be unqualified, it needs to be discharged externally, and the pneumatic diaphragm pump and the waste liquid discharge valve are opened to clean the stored liquid in the main oil collecting tank in time. A sight glass is set on the first pipeline at the top of the filter to facilitate the observation of the leakage of the sealing liquid. If the leakage is linear, the equipment needs to be adjusted; a sampling valve is set on the second pipeline for regular detection of the purity of the isolation liquid; a waste liquid discharge valve is set downstream of the switch valve for harmless treatment of the sealing liquid (sealing liquid in the sealing liquid tank) when it is unqualified.

[0039] Example 2

[0040] On the basis of Example 1, the following improvements were made: Figure 1 As shown, in order to facilitate oil replenishment, the high-pressure propylene pump sealing liquid recovery circulation system also includes an oil replenishment valve, which is arranged at one end of the third pipeline connected to the inlet of the pneumatic diaphragm pump for normal oil replenishment. When it is necessary to replenish the sealing liquid tank with sealing liquid, open the oil replenishment valve, the switch valve and the pneumatic diaphragm pump for liquid replenishment. In order to reduce the setting of power equipment, the high-pressure propylene pump, the first pipeline, the filter, the second pipeline and the main oil collecting tank are arranged in sequence from top to bottom, that is, the high-pressure propylene pump is at a high position and the main oil collecting tank is arranged at a low position. The first pipeline and the second pipeline are made of stainless steel. In this way, the sealing liquid, under the action of gravity, enters the main oil collecting tank from top to bottom after passing through the external discharge cavity of the mechanical seal on the high-pressure propylene pump, the first pipeline, the filter and the second pipeline in sequence. The liquid level meter is connected to the main oil collecting tank by a flange.

[0041] Example 3

[0042] On the basis of Example 2, the following improvements are further made: in order to ensure continuous filtering, the filter includes a first filter and a second filter in parallel; one end of the first pipeline is connected to the external discharge cavity of the mechanical seal on the high-pressure propylene pump, and the other end of the first pipeline is branched into two ways, respectively connected to the first filter inlet and the second filter inlet, and the first filter inlet and the second filter inlet are both provided with a control valve; one end of the second pipeline is branched into two ways, respectively connected to the first filter outlet and the second filter outlet, and the first filter outlet and the second filter outlet are both provided with a control valve, and the other end of the second pipeline is connected to the top of the main oil collection tank. The two filters can be switched to ensure smooth filtering.

[0043] Example 4

[0044] On the basis of Example 2, the following improvements were made: Figure 1 As shown, in order to ensure continuous filtration, the filter is a double filter. The double filter includes two parallel stainless steel filters, and the two filters can be switched to ensure smooth filtration.

[0045] Example 5

[0046] On the basis of Example 3 or 4, the following improvements were further made: Figure 1 As shown, in order to facilitate automation, the above-mentioned high-pressure propylene pump sealing liquid recovery and circulation system also includes a PLC control box, and the switch valve, pneumatic diaphragm pump and liquid level meter are all connected to the PLC control box and controlled by the PLC control box. In the figure, plan 11 represents the self-flushing process, specifically the flushing process of liquid flowing from the pump outlet to the sealing chamber; Plan 54 represents the external flushing process, specifically the pressurized sealing liquid flows to another sealing chamber of the mechanical seal, all of which play the role of sealing, cooling and cleaning.

[0047] When using the above-mentioned high-pressure propylene pump sealing liquid recovery circulation system, the flowing sealing liquid passes through the first pipeline, and then passes through the root valve and the sight glass in turn, and reaches the filter for filtration. The filtered sealing liquid flows into the main oil collecting tank through the second pipeline. When the liquid level meter detects that the liquid level of the sealing liquid in the main oil collecting tank is too high, the PLC control box controls the switch valve and the pneumatic diaphragm pump to open, and then the sealing liquid in the main oil collecting tank is injected into the sealing liquid tank under the drive of the pneumatic diaphragm pump. When the liquid level meter detects that the liquid level of the sealing liquid reaches a low level, the PLC control box controls the switch valve and the pneumatic diaphragm pump to close. In addition, when the mechanical seal leaks internally and the sealing liquid tank needs to be supplemented with sealing liquid, the oil replenishing valve, the switch valve and the pneumatic diaphragm pump can be manually controlled for liquid replenishment; when the sealing liquid sampled by the sampling valve is detected to be unqualified, it needs to be discharged externally, and the pneumatic diaphragm pump and the waste liquid discharge valve can be manually opened to clean the stored liquid in the main oil collecting tank in time.

[0048] The high-pressure propylene pump sealing liquid recovery and circulation system in the above-mentioned examples adopts a closed filtering, collecting and replenishing method. The recovery process is clean, avoiding discharge into the dirty oil system and saving secondary treatment costs. The sealing liquid recovery efficiency is high, reducing the loss of sealing liquid, and can save more than 500,000 yuan in the cost of purple crown sealing liquid each year; it reduces the risk of direct operation links; improves the utilization rate of sealing liquid, reduces the labor intensity of on-site maintenance, and reduces the cost of sewage treatment; further, it improves the degree of automation, makes impossible manual collection possible, reduces the number of mechanical seal replacements, and saves millions of dollars each year.

Claims

1. A high-pressure propylene pump sealing liquid recovery and circulation system, characterized in that: It comprises a high-pressure propylene pump (1), a first pipeline (2), a root valve (3), a sight glass (4), a filter (5), a second pipeline (6), a sampling valve (7), a main body oil collecting tank (8), a third pipeline (9), a pneumatic diaphragm pump (10), a fourth pipeline (11), a switch valve (12), a waste liquid discharge valve (13) and a sealed liquid tank (14); One end of the first pipeline (2) is connected to the external discharge cavity of the mechanical seal on the high-pressure propylene pump (1), and the other end is connected to the inlet of the filter (5); the root valve (3) and the sight glass (4) are arranged on the first pipeline (2); one end of the second pipeline (6) is connected to the outlet of the filter (5), and the other end is connected to the top of the main body oil collecting tank (8), and the sampling valve (7) is arranged on the second pipeline (6); the main body oil collecting tank (8) is provided with a liquid level meter (16); One end of the third pipeline (9) is connected to the bottom of the side wall of the main body oil collecting tank (8), and the other end is connected to the inlet of the pneumatic diaphragm pump (10); one end of the fourth pipeline (11) is connected to the outlet of the pneumatic diaphragm pump (10), and the other end is connected to the sealing liquid tank (14); the switch valve (12) and the waste liquid discharge valve (13) are arranged on the end of the fourth pipeline (11) connected to the outlet of the pneumatic diaphragm pump (10), and the waste liquid discharge valve (13) is located downstream of the switch valve (12); the sealing liquid tank (14) is cyclically connected to the discharge cavity of the mechanical seal on the high-pressure propylene pump (1).

2. The high-pressure propylene pump sealing liquid recovery and circulation system according to claim 1, characterized in that: It also includes an oil replenishing valve (17), which is arranged on one end of the third pipeline (9) connected to the inlet of the pneumatic diaphragm pump (10).

3. The high-pressure propylene pump sealing liquid recovery and circulation system according to claim 1 or 2, characterized in that: The high-pressure propylene pump (1), the first pipeline (2), the filter (5), the second pipeline (6) and the main body oil collecting tank (8) are arranged in sequence from top to bottom.

4. The high-pressure propylene pump sealing liquid recovery and circulation system according to claim 3, characterized in that: The first pipeline (2) and the second pipeline (6) are made of stainless steel.

5. The high-pressure propylene pump sealing liquid recovery and circulation system according to claim 1 or 2, characterized in that: The filter (5) comprises a first filter and a second filter connected in parallel; the other end of the first pipeline (2) is branched into two paths, respectively connected to the first filter inlet and the second filter inlet, and the first filter inlet and the second filter inlet are both provided with control valves; one end of the second pipeline (6) is branched into two paths, respectively connected to the first filter outlet and the second filter outlet, and the first filter outlet and the second filter outlet are both provided with control valves.

6. The high-pressure propylene pump sealing liquid recovery and circulation system according to claim 1 or 2, characterized in that: The filter (5) is a duplex filter.

7. The high-pressure propylene pump sealing liquid recovery and circulation system according to claim 1 or 2, characterized in that: It also comprises a PLC control box (15), and the switch valve (12), the pneumatic diaphragm pump (10) and the liquid level meter (16) are all connected to the PLC control box (15) and controlled by the PLC control box (15).

8. The high-pressure propylene pump sealing liquid recovery and circulation system according to claim 1 or 2, characterized in that: The liquid level meter (16) is connected to the main body oil collecting tank (8) via a flange.

9. The high-pressure propylene pump sealing liquid recovery and circulation system according to claim 1 or 2, characterized in that: One end of the first pipeline (2) is in communication with the secondary sealing rear external discharge cavity of the mechanical seal on the high-pressure propylene pump (1).

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