Online drainage system of liquid ring vacuum pump

Abstract

The utility model discloses an online drainage system of a liquid ring vacuum pump, and belongs to the technical field of chemical production. Comprising an inlet buffer tank connected with an external production system; the inlet end of the liquid ring vacuum pump is connected with the inlet buffer tank, gas in the production system is extracted through the liquid ring vacuum pump, an overflow hole is formed in the liquid ring vacuum pump, the inlet buffer tank is communicated with the overflow hole through a condensate drain pipeline, and a liquid level adjusting valve is arranged on the condensate drain pipeline; and the inlet buffer tank and the liquid ring vacuum pump are respectively connected with the waste liquid collecting tank through respective system emptying pipelines. Through the arrangement of the condensate drain pipeline, the liquid level in the inlet buffer tank cannot rise to the position of a pipeline opening, it is guaranteed that gas and condensate cannot be mixed when the liquid ring vacuum pump extracts gas, and therefore increase of suction resistance is avoided, and the higher the vacuum degree of the liquid ring vacuum pump is, the higher the condensate drain pipeline is. The working performance of the liquid ring vacuum pump is improved, and long-term stable operation of the liquid ring vacuum pump is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of chemical production, specifically relates to a liquid ring vacuum pump on -line drainage system. BACKGROUND

[0002] In the application of the existing liquid ring vacuum pump, because the production system contains light hydrocarbon gas, condensate can be produced under the negative pressure environment of the inlet buffer tank of the liquid ring vacuum pump, and the usual practice is to discharge these condensate to the waste liquid collecting tank through the condensate discharge line at the bottom of the inlet buffer tank, and according to the liquid level of the waste liquid collecting tank, the pump is automatically started to send the waste liquid to treatment. This mode realizes the circulation operation, closed discharge and zero pollution, and is widely used in practical application because of its convenient connection and simple use.

[0003] However, this drainage mode has the following main problems:

[0004] 1, pressure difference leads to poor drainage: the working pressure of the waste liquid collecting tank is higher than that of the inlet buffer tank, which makes it difficult for the condensate in the inlet buffer tank to be discharged into the waste liquid collecting tank, resulting in continuous accumulation of condensate in the inlet buffer tank.

[0005] 2, increased suction resistance: as the condensate accumulates, the liquid level in the inlet buffer tank gradually rises, and it may even reach the position of the inlet pipeline, which will cause the gas to mix with the condensate when the liquid ring vacuum pump is pumping, increasing the suction resistance of the liquid ring vacuum pump and affecting its normal working performance. INVENTION CONTENTS

[0006] The utility model is directed to the above problems existing in the prior art, and proposes a liquid ring vacuum pump on-line drainage system capable of avoiding increase of suction resistance of the liquid ring vacuum pump.

[0007] The utility model can be realized by the following technical schemes:

[0008] A liquid ring vacuum pump on-line drainage system, comprising:

[0009] An inlet buffer tank connected to an external production system, the inlet buffer tank having an inlet buffer tank liquid level control system composed of a first remote liquid level meter and a first remote liquid level transmitter, the first remote liquid level meter being used to detect the liquid level value of the inlet buffer tank and transmit a corresponding current signal to the control system through the first remote liquid level transmitter according to the detected liquid level value;

[0010] A liquid ring vacuum pump having an inlet end connected to the inlet buffer tank, the liquid ring vacuum pump being used to pump gas in the production system, the liquid ring vacuum pump being provided with an overflow hole, the inlet buffer tank being connected to the overflow hole through a condensate discharge pipeline, and a liquid level regulating valve being arranged on the condensate discharge pipeline;

[0011] a waste liquid collection tank, the inlet buffer tank and the liquid ring vacuum pump are connected with the waste liquid collection tank through respective system emptying pipelines;

[0012] The control system automatically controls the opening degree of the liquid level regulating valve according to the real-time liquid level value in the inlet buffer tank.

[0013] As a further improvement of the utility model, a gas-liquid separation tank is further arranged, which is connected with the outlet end of the liquid ring vacuum pump, the top and bottom of the gas-liquid separation tank are respectively provided with an exhaust pipeline and a liquid discharge pipeline, the light hydrocarbon-rich non-condensable gas separated by the gas-liquid separation tank is discharged to a flare through the exhaust pipeline, and the separated liquid is used for repeated circulation of the liquid ring vacuum pump, and meanwhile, the waste liquid is discharged to the waste liquid collection tank through the liquid discharge pipeline.

[0014] As a further improvement of the utility model, a pump liquid supply pipeline is further arranged between the bottom of the gas-liquid separation tank and the inlet end of the liquid ring vacuum pump, and a sealing flushing pump and a heat exchanger are arranged on the pump liquid supply pipeline.

[0015] The liquid outlet of the liquid ring vacuum pump, the gas-liquid separation tank, the sealing flushing pump, the heat exchanger and the liquid inlet of the liquid ring vacuum pump are sequentially connected to form a circulation system.

[0016] As a further improvement of the utility model, the gas-liquid separation tank is further connected with a reflux pipeline, the reflux pipeline is connected with the inlet buffer tank, and part of the gas discharged from the top of the gas-liquid separation tank is discharged to the inlet buffer tank through the reflux pipeline.

[0017] As a further improvement of the utility model, a demister is arranged on the top of the gas-liquid separation tank, and the non-condensable gas separated by the demister is removed of liquid components.

[0018] As a further improvement of the utility model, a liquid supplement pipeline is further arranged, which is connected with the gas-liquid separation tank and used for supplementing working liquid.

[0019] As a further improvement of the utility model, a gas-liquid separation tank liquid level control system is further arranged,

[0020] The gas-liquid separation tank liquid level control system is composed of a second remote liquid level meter and a second remote liquid level transmitter, the second remote liquid level meter is used for real-time detection of the liquid level in the gas-liquid separation tank, and the second remote liquid level transmitter is used for output of a high liquid level current signal corresponding to the liquid level in the gas-liquid separation tank to the control system.

[0021] When the liquid level in the gas-liquid separation tank is higher than a preset value, the second remote liquid level meter outputs a corresponding high liquid level current signal to the control system, and the control system opens a liquid discharge regulating valve arranged on the liquid discharge pipeline.

[0022] When the liquid level in the gas-liquid separation tank is lower than the preset value, the second remote liquid level meter outputs a corresponding low liquid level current signal to the control system, and the control system opens a liquid supplementing switch valve arranged on the liquid supplementing pipeline.

[0023] As a further improvement of the utility model, a magnetic oxygen analyzer and a nitrogen purge pipeline are connected to the exhaust pipeline, and when the magnetic oxygen analyzer detects that the oxygen content in the exhaust pipeline exceeds a preset value, nitrogen is released through the nitrogen purge pipeline to dilute the oxygen concentration by purging the exhaust regulating valve in the exhaust pipeline.

[0024] As a further improvement of the utility model, a nitrogen pressure supplementing pipeline is connected to the waste liquid collecting tank, and when the pressure in the waste liquid collecting tank is lower than a preset value, nitrogen is supplied to supplement the internal pressure.

[0025] As a further improvement of the utility model, a pressure relief pipeline is arranged between the waste liquid collecting tank and the inlet buffer tank, and when the pressure in the waste liquid collecting tank is higher than a preset value, the waste liquid collecting tank is relieved through the pressure relief pipeline to the inlet buffer tank.

[0026] Compared with the prior art, the utility model has the following beneficial effects:

[0027] 1. An overflow hole is arranged on the liquid ring vacuum pump, the bottom of the inlet buffer tank is connected to the overflow hole through a condensate discharge pipeline, and the liquid in the inlet buffer tank can form a self-suction force by using the negative pressure in the working cavity of the liquid ring vacuum pump, and is discharged through the condensate discharge pipeline to the cavity of the liquid ring vacuum pump for circulation. The liquid level in the inlet buffer tank will not rise to the position of the pipeline port due to the arrangement of the condensate discharge pipeline, so that the mixing of gas and condensate will not occur when the liquid ring vacuum pump pumps gas, thereby avoiding the increase of suction resistance, and the vacuum degree that can be reached by the liquid ring vacuum pump is higher, which not only improves the working performance of the liquid ring vacuum pump, but also ensures its long-term stable operation.

[0028] 2. The design of the inlet buffer tank liquid level control system enables the liquid level regulating valve on the condensate discharge pipeline to automatically control its opening degree, realizes precise monitoring and adjustment of the liquid level in the inlet buffer tank, has high automation degree, reduces the need for manual intervention, and improves work efficiency.

[0029] 3、Into the rich light hydrocarbon non-condensable gas in the liquid ring vacuum pump, discharge to the gas-liquid separation tank for gas-liquid separation, the non-condensable gas separated out of the gas-liquid separation tank is discharged to the flare through the exhaust pipeline, successfully solve the problem of non-condensable gas leading to the working performance of the liquid ring vacuum pump, and without frequent replenishment of fresh carbon nine working fluid, the liquid phase is sent into the waste liquid collection tank through the liquid discharge pipeline, and then the part of liquid is sent to the external recycling device for recycling through the waste liquid external sending pump, realize resource recycling, thereby on the one hand solve the environmental protection pressure caused by large water discharge, on the other hand also solve the safety hidden trouble problem existing in the water discharge containing organic solvent and toxic substances;

[0030] 4、The design of the liquid level control system of the gas-liquid separation tank can ensure that the working fluid in the gas-liquid separation tank always remains in an optimal liquid level range, avoiding the performance decline caused by too high or too low liquid level;

[0031] 5、The circulating system formed through the pump liquid supply pipeline cools and reduces the temperature of the working fluid of the liquid ring vacuum pump, so as to maintain the optimal working state of the liquid ring vacuum pump, avoid the performance decline caused by temperature fluctuation or impurities of the working fluid, through the efficient cooling and circulating system, unnecessary water resource consumption and other resource waste are reduced, and effective utilization of resources is realized;

[0032] 6、On the exhaust pipeline, the combination of the magnetic oxygen analyzer and the nitrogen purging system realizes instant response to the change of oxygen content, can take measures quickly when the oxygen content exceeds the standard, and guarantees the safe operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 is the flow chart of the online liquid discharge system of the liquid ring vacuum pump of the utility model;

[0034] Fig. 2 is the discharge path schematic view of the condensate in the online liquid discharge system of the liquid ring vacuum pump of the utility model.

[0035] In the figure, 100, inlet buffer tank;110, first remote liquid level transmitter;120, condensate discharge pipeline;130, system emptying pipeline;

[0036] 200, liquid ring vacuum pump;210, pump liquid supply pipeline;220, seal flushing pump;230, heat exchanger;

[0037] 300, waste liquid collection tank;310, waste liquid external sending pump;320, nitrogen pressure supplement pipeline;330, pressure relief pipeline;

[0038] 400. Gas-liquid separator; 410. Exhaust line; 411. Magnetic oxygen analyzer; 412. Nitrogen purging line; 420. Drain line; 430. Return line; 440. Demister; 450. Liquid replenishment line; 460. Second remote level transmitter. Detailed Implementation

[0039] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. The technical methods of the present invention will be further described, but the present invention is not limited to these embodiments.

[0040] like Figs. 1-2 As shown, this utility model provides an online liquid discharge system for a liquid ring vacuum pump, comprising:

[0041] The inlet buffer tank 100 is connected to the external production system. The inlet buffer tank 100 has an inlet buffer tank level control system consisting of a first remote level gauge (not shown in the figure) and a first remote level transmitter 110. The first remote level gauge is used to detect the level value of the inlet buffer tank 100 and transmits a corresponding current signal to the control system according to the detected level value through the first remote level transmitter 110.

[0042] The liquid ring vacuum pump 200 has its inlet end connected to the inlet buffer tank 100. The liquid ring vacuum pump 200 extracts gas from the production system. The liquid ring vacuum pump 200 has an overflow hole. The inlet buffer tank 100 is connected to the overflow hole through the condensate drain line 120. The condensate in the inlet buffer tank 100 can enter the liquid ring vacuum pump 200 in sequence through the condensate drain line 120 and the overflow hole. The condensate drain line 120 is equipped with a liquid level regulating valve.

[0043] Waste liquid collection tank 300, inlet buffer tank 100 and liquid ring vacuum pump 200 are respectively connected to waste liquid collection tank 300 through their respective system evacuation pipelines 130;

[0044] The control system automatically controls the opening degree of the liquid level regulating valve based on the real-time liquid level value in the inlet buffer tank 100.

[0045] It should be noted that in the prior art, because the working pressure of the waste liquid collection tank 300 is higher than that of the inlet buffer tank 100, the condensate in the inlet buffer tank 100 is difficult to be discharged smoothly into the waste liquid collection tank 300. As a result, the condensate accumulates in the inlet buffer tank 100. As the condensate accumulates, the liquid level in the inlet buffer tank 100 gradually rises, and may even reach the pipeline inlet. This situation will cause the gas and condensate to mix when the liquid ring vacuum pump 200 is pumping gas, which will increase the suction resistance of the liquid ring vacuum pump 200 and affect its normal working performance.

[0046] To solve this problem, the overflow hole (not shown in the figure) is opened on the liquid ring vacuum pump 200, and the bottom of the inlet buffer tank 100 is communicated with the overflow hole through the condensate discharge pipeline 120. Specifically, since the liquid ring vacuum pump 200 has a self-suction function, and the vacuum degree at the inlet of the liquid ring vacuum pump 200 is lower than that at the inlet of the inlet buffer tank 100, at the same time, the liquid level in the inlet buffer tank 100 has its own gravity, and the center line of the liquid level meter is on the same horizontal plane as the center line of the liquid ring vacuum pump 200. Thus, the liquid in the inlet buffer tank 100 can form a self-suction force by using the negative pressure in the working chamber of the liquid ring vacuum pump 200, and is discharged to the cavity of the liquid ring vacuum pump 200 through the condensate discharge pipeline 120 for circulation.

[0047] It is through the setting of the condensate discharge pipeline 120 that the liquid level in the inlet buffer tank 100 will not rise to the position of the pipeline port, ensuring that the gas will not mix with the condensate when the liquid ring vacuum pump 200 is pumping gas, thereby avoiding the increase of the suction resistance, and the vacuum degree that the liquid ring vacuum pump 200 can reach is higher, which not only improves the working performance of the liquid ring vacuum pump 200, but also ensures its long-term stable operation.

[0048] And the design of the inlet buffer tank liquid level control system makes the liquid level regulating valve on the condensate discharge pipeline 120 automatically control its opening degree, realizing precise monitoring and adjustment of the liquid level in the inlet buffer tank 100, with high automation degree, reducing the need for manual intervention and improving work efficiency. In actual application process, the control system automatically opens the liquid level regulating valve when the liquid level in the inlet buffer tank 100 is higher than 70%, starts to discharge liquid, and automatically closes the liquid level regulating valve when the liquid level in the inlet buffer tank 100 is lower than 10%, stops discharging liquid.

[0049] In addition, since the light hydrocarbon non-condensable gas is sucked into the liquid ring vacuum pump 200, the working performance of the liquid ring vacuum pump 200 decreases significantly. To reduce the working temperature of the liquid ring vacuum pump 200, fresh carbon nine working fluid is frequently used to replace the working fluid of the liquid ring vacuum pump 200, and the too high working temperature has a great influence on the working performance of the liquid ring vacuum pump 200.

[0050] To solve this problem, a gas-liquid separation tank 400 is provided in the embodiment, which is connected with the outlet end of the liquid ring vacuum pump 200. The top and bottom of the gas-liquid separation tank 400 are respectively provided with a gas discharge pipeline 410 and a liquid discharge pipeline 420. The light hydrocarbon non-condensable gas separated by the gas-liquid separation tank 400 is discharged to the flare through the gas discharge pipeline 410, and the liquid separated by the gas-liquid separation tank 400 is used for recycling, and the waste liquid is discharged to the waste liquid collection tank 300 through the liquid discharge pipeline 420.

[0051] By the setting of the gas-liquid separation tank 400, the problem of the working performance of the liquid ring vacuum pump 200 caused by the rich light hydrocarbon non-condensable gas entering the liquid ring vacuum pump 200 is successfully solved, and the fresh carbon nine working liquid does not need to be frequently supplemented.

[0052] Further, the bottom of the gas-liquid separation tank 400 and the inlet end of the liquid ring vacuum pump 200 are further provided with a pump liquid supply pipeline 210, the pump liquid supply pipeline 210 is provided with a sealing flushing pump 220 and a heat exchanger 230, wherein,

[0053] The liquid outlet of the liquid ring vacuum pump 200, the gas-liquid separation tank 400, the sealing flushing pump 220, the heat exchanger 230, and the liquid inlet of the liquid ring vacuum pump 200 are sequentially connected and form a circulation system.

[0054] Through the circulation system formed by the pump liquid supply pipeline 210, the heat exchanger 230 can cool the working liquid ready to enter the liquid ring vacuum pump 200, so as to maintain the best working state of the liquid ring vacuum pump 200, avoid the performance decline caused by the temperature fluctuation or impurities of the working liquid, and reduce unnecessary water consumption and other resource waste through the efficient cooling and circulation system, so as to realize the effective utilization of resources.

[0055] The cooling medium of the heat exchanger 230 can be chilled water or circulating water, when the chilled water is used as the cooling medium, the temperature is controlled at 3-5°C, and when the circulating water is used as the cooling medium, the temperature is controlled at less than 34°C.

[0056] Preferably, the gas-liquid separation tank 400 is further connected with a backflow pipeline 430, the backflow pipeline 430 is connected with the inlet buffer tank 100, part of the gas discharged from the top of the gas-liquid separation tank 400 is discharged to the inlet buffer tank 100 through the backflow pipeline 430, and the backflow pipeline 430 is provided with a backflow regulating valve, so as to adjust the proportion and rate of the backflow gas according to the actual needs.

[0057] The backflow pipeline 430 has the following effects:

[0058] 1. If the discharge pressure of the gas-liquid separation tank 400 is higher than the specified value, the motor current is too high and the motor is easy to burn out, at this time, the backflow regulating valve on the backflow pipeline 430 can be manually controlled, so that part of the gas flows back to the inlet of the liquid ring vacuum pump 200, thereby reducing the pressure of the gas-liquid separation tank 400;

[0059] 2. When the production system is in a vacuum state, the unit cannot be immediately connected with the production system when it is started, the backflow pipeline 430 can be opened, the liquid ring vacuum pump 200 is started, the gas circulates in the unit, when the vacuum degree of the production system is reached, the valve of the production system can be slowly opened, and then the backflow regulating valve is closed, at this time, the backflow pipeline 430 can be used as a buffer.

[0060] 3. When the liquid ring vacuum pump 200 produces a large cavitation noise, the gas backflow can be used to eliminate the cavitation phenomenon by opening the backflow regulating valve, thereby reducing the damage to the liquid ring vacuum pump 200.

[0061] Preferably, the top of the gas-liquid separation tank 400 is provided with a demister 440, and the non-condensable gas separated by the demister 440 removes the liquid phase components, that is, the gas discharged from the top of the gas-liquid separation tank 400 is subjected to secondary separation by the demister 440, and after removing the liquid phase components, it is discharged to the flare or the backflow pipeline 430 through the gas discharge pipeline 410;

[0062] On the one hand, by efficiently removing the liquid phase components in the gas, the possibility of harmful substances being discharged with the gas is reduced, and the risk of environmental pollution is reduced. On the other hand, the captured liquid phase components can be returned to the bottom of the gas-liquid separation tank 400 and enter the circulation system or be sent to the waste liquid collection tank 300 for recycling, thereby achieving effective recycling of resources.

[0063] Preferably, it further comprises a liquid supplement pipeline 450 connected to the gas-liquid separation tank 400 and used for supplementing the working liquid, so that the liquid level in the gas-liquid separation tank 400 is maintained at an appropriate level.

[0064] Further, it further comprises a gas-liquid separation tank 400 liquid level control system, which is composed of a second remote liquid level meter (not shown in the figure) and a second remote liquid level transmitter 460. The second remote liquid level meter is used to detect the liquid level in the gas-liquid separation tank 400 in real time, wherein,

[0065] When the liquid level in the gas-liquid separation tank 400 is higher than the preset value, the second remote liquid level meter outputs a corresponding high liquid level current signal to the control system, and the control system opens the liquid discharge regulating valve arranged on the liquid discharge pipeline;

[0066] When the liquid level in the gas-liquid separation tank 400 is lower than the preset value, the second remote liquid level meter outputs a corresponding low liquid level current signal to the control system, and the control system opens the liquid supplement on-off valve arranged on the liquid supplement pipeline.

[0067] At the same time, the control system can also control the start and stop of the waste liquid delivery pump 310 according to the high and low liquid level signals fed back by the gas-liquid separation tank 400. When the liquid level in the gas-liquid separation tank 400 is higher than the preset value, the control system starts the waste liquid delivery pump 310 to realize automatic liquid discharge. When the liquid level in the gas-liquid separation tank 400 is lower than the preset value, the control system stops the waste liquid delivery pump 310 to realize automatic liquid discharge.

[0068] Through the setting of the gas-liquid separation tank liquid level control system, it can be ensured that the working liquid in the gas-liquid separation tank 400 is always maintained within an optimal liquid level range, thereby avoiding the performance degradation caused by excessively high or low liquid level.

[0069] Preferably, a magnetic oxygen analyzer 411 and a nitrogen purge line 412 are connected to the exhaust line 410, when the magnetic oxygen analyzer 411 detects that the oxygen content in the exhaust line 410 exceeds a preset value, nitrogen is released through the nitrogen purge line 412 to purge the exhaust regulating valve in the exhaust line 410 to dilute the oxygen concentration;

[0070] It should be noted that for the case of discharging non-condensable gas to the flare combustion, maintaining appropriate oxygen content helps to achieve a more complete and stable combustion process, reducing the generation of harmful by-products (such as carbon monoxide, incompletely combusted hydrocarbons), but too high oxygen concentration poses a risk of combustion explosion, and the combination of the magnetic oxygen analyzer 411 and the nitrogen purge system enables immediate response to changes in oxygen content, enabling rapid action when oxygen content exceeds the standard, ensuring safe operation of the system.

[0071] Preferably, a nitrogen pressure supplement line 320 is connected to the waste liquid collection tank 300, which supplements the internal pressure of the waste liquid collection tank 300 with nitrogen when the pressure in the waste liquid collection tank 300 is below a preset value, in addition, a pressure relief line 330 is provided between the waste liquid collection tank 300 and the inlet buffer tank 100, when the pressure in the waste liquid collection tank 300 is higher than the preset value, the waste liquid collection tank 300 is relieved through the pressure relief line 330 to the inlet buffer tank 100 400, thereby ensuring that the pressure in the waste liquid collection tank 300 is always maintained within an optimal range, avoiding performance degradation due to low pressure.

[0072] The technical means disclosed in the utility model scheme are not limited to the technical means disclosed in the above technical means, and also include technical solutions composed of any combination of the above technical features. The above is the specific implementation of the utility model, and it should be pointed out that for ordinary technical personnel in the technical field, without departing from the principle of the utility model, a number of improvements and refinements can be made, and these improvements and refinements are also considered within the protection scope of the utility model.

[0073] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the utility model embodiment are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), if the certain posture changes, the directional indications also change accordingly.

[0074] In addition, the descriptions such as "first", "second", "one", etc. in the present application are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited. The terms "connection", "fixing", etc. should be understood broadly, for example, "fixing" can be fixed connection, or detachable connection, or integrated; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium; can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0075] The technical solutions of various embodiments of the present application can be combined with each other, but must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, also not within the protection scope required by the present application.

[0076] The specific embodiments described herein are merely illustrative of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, but will not deviate from the spirit of the present application or exceed the scope defined by the appended claims.

Claims

1. A liquid ring vacuum pump on-line liquid discharge system, characterized by, The application relates to a liquid ring vacuum pump system, which comprises the following components: an inlet buffer tank connected with an external production system, wherein the inlet buffer tank is provided with an inlet buffer tank liquid level control system composed of a first remote liquid level meter and a first remote liquid level transmitter, the first remote liquid level meter is used for detecting the liquid level value of the inlet buffer tank, and a corresponding current signal is transmitted to a control system according to the detected liquid level value through the first remote liquid level transmitter; a liquid ring vacuum pump, an inlet end of which is connected with the inlet buffer tank, gas in the production system is extracted through the liquid ring vacuum pump, the liquid ring vacuum pump is provided with an overflow hole, the inlet buffer tank is communicated with the overflow hole through a condensate discharge pipeline, and a liquid level adjusting valve is arranged on the condensate discharge pipeline; a waste liquid collecting tank, the inlet buffer tank and the liquid ring vacuum pump are respectively connected with the waste liquid collecting tank through respective system emptying pipelines; a control system, which automatically controls the opening degree of the liquid level adjusting valve according to the real-time liquid level value in the inlet buffer tank.

2. The online liquid draining system of a liquid ring vacuum pump according to claim 1, characterized in that, The application further comprises a gas-liquid separation tank, which is connected with the outlet end of the liquid ring vacuum pump, the top and bottom of the gas-liquid separation tank are respectively provided with a gas discharge pipeline and a liquid discharge pipeline, high-temperature non-condensable gas separated by the gas-liquid separation tank is discharged to a flare through the gas discharge pipeline, the separated liquid is used for recycling by the liquid ring vacuum pump, and waste liquid is discharged to the waste liquid collecting tank through the liquid discharge pipeline.

3. The online liquid draining system of a liquid ring vacuum pump according to claim 2, characterized in that, The bottom of the gas-liquid separation tank and the inlet end of the liquid ring vacuum pump are further provided with a pump liquid supply pipeline, the pump liquid supply pipeline is provided with a sealing flushing pump and a heat exchanger, wherein the liquid outlet of the liquid ring vacuum pump, the gas-liquid separation tank, the sealing flushing pump, the heat exchanger and the liquid inlet of the liquid ring vacuum pump are sequentially connected and form a circulation system. The gas-liquid separation tank is further connected with a backflow pipeline, the backflow pipeline is connected with the inlet buffer tank, and part of the gas discharged from the top of the gas-liquid separation tank is discharged to the inlet buffer tank through the backflow pipeline.

4. The online liquid draining system of a liquid ring vacuum pump according to claim 2, characterized in that, The top of the gas-liquid separation tank is provided with a demister, and the non-condensable gas separated by the demister is removed of liquid phase components.

5. The online liquid draining system of a liquid ring vacuum pump according to claim 2, characterized in that, The application further comprises a liquid supplement pipeline, which is connected with the gas-liquid separation tank and is used for supplementing working liquid.

6. The online liquid draining system of a liquid ring vacuum pump according to claim 2, wherein The application further comprises a gas-liquid separation tank liquid level control system, 7. The online liquid draining system of a liquid ring vacuum pump according to claim 6, characterized in that, which is composed of a second remote liquid level meter and a second remote liquid level transmitter, the second remote liquid level meter is used for detecting the liquid level in the gas-liquid separation tank in real time, wherein when the liquid level in the gas-liquid separation tank is higher than a preset value, the second remote liquid level meter outputs a corresponding high liquid level current signal to the control system, and the control system opens a liquid discharge adjusting valve arranged on the liquid discharge pipeline; when the liquid level in the gas-liquid separation tank is lower than a preset value, the second remote liquid level meter outputs a corresponding low liquid level current signal to the control system, and the control system opens a liquid supplement on-off valve arranged on the liquid supplement pipeline. The application further comprises that a magnetic oxygen analyzer and a nitrogen blowing pipeline are connected with the gas discharge pipeline, when the magnetic oxygen analyzer detects that the oxygen content on the gas discharge pipeline exceeds a preset value, nitrogen is released through the nitrogen blowing pipeline and is used for blowing the gas discharge adjusting valve on the gas discharge pipeline to dilute the oxygen concentration.

8. The online liquid draining system of a liquid ring vacuum pump according to claim 2, wherein ​ 9. The online liquid draining system of a liquid ring vacuum pump according to claim 1, wherein A nitrogen pressure supplement pipeline is further connected to the waste liquid collecting tank, and nitrogen is used to supplement the internal pressure of the waste liquid collecting tank when the pressure in the waste liquid collecting tank is lower than a preset value.

10. The online liquid draining system of a liquid ring vacuum pump according to claim 1, wherein A pressure relief pipeline is further arranged between the waste liquid collecting tank and the inlet buffer tank, and the waste liquid collecting tank is relieved through the pressure relief pipeline to the inlet buffer tank when the pressure in the waste liquid collecting tank is higher than a preset value.

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