Device for preventing liquid in vacuum pump

Abstract

The utility model discloses a device for preventing liquid from being carried in vacuum pumps, which belongs to the technical field of C9 resin fractionation and purification, and comprises a working vacuum pump and a standby vacuum pump which are arranged side by side, the input ends of the two vacuum pumps are respectively connected with a fractionating tower through pipelines, and the output ends of the two vacuum pumps are respectively connected with output pipelines extending downwards; a buffer tank is arranged on one side of the working vacuum pump, a feed port of the buffer tank is connected with a tail gas pipeline, the tail gas pipeline is communicated with the two output pipelines far away from the buffer tank, a tail gas outlet is formed in the top end of the buffer tank, the tail gas pipeline is located below the working vacuum pump and the standby vacuum pump, and the tail gas outlet is connected with a tail gas treatment system. The buffer tank is arranged to eliminate the height difference between the vacuum pumps and the tail gas treatment system, so that when the tail gas pipeline is positioned below the two vacuum pumps, gas is discharged from the working vacuum pump and directly enters the tail gas pipeline downwards through the output pipeline, liquid cannot flow back into the two vacuum pumps, and meanwhile, the gas cannot be discharged into the tail gas treatment system.

Description

Technical Field

[0001] The utility model relates to the technical field of fractionation and purification of carbon nine resin, in particular to a device for preventing liquid from being carried inside a vacuum pump. Background Art

[0002] During the purification process of C9 resin, hydrocarbon compounds with a carbon content of less than 9 are converted into gases through fractional distillation. The gases are then expelled from the reaction system via a vacuum pump. After entering the vacuum pump, the gases are discharged through the vacuum pump's output pipe into the exhaust pipe, and finally into the exhaust gas treatment system for further treatment. Because the exhaust gas treatment system is located above the vacuum pump, the exhaust gas pipe connecting the exhaust gas treatment system and the vacuum pump output is often installed above the vacuum pump. Furthermore, to prevent production interruptions due to damage to the working vacuum pump during production, a backup vacuum pump is often installed, with its output connected in parallel to the working vacuum pump's output, into the same exhaust gas pipe.

[0003] However, in actual applications, when the vacuum pump extracts gas, it will inevitably carry a small amount of liquid in the gas. When the small amount of liquid moves upward with the gas into the exhaust pipe, under the action of gravity, part of the liquid will move downward, causing the following consequences:

[0004] 1. The liquid flows into the standby vacuum pump along the pipeline, causing damage to the standby vacuum pump;

[0005] 2. The liquid flows back downward into the chamber of the working vacuum pump, causing the chamber of the working vacuum pump to enter the liquid, reducing the life of the vacuum pump;

[0006] 3. When the gas enters the exhaust pipe, part of the gas condenses into liquid and enters the standby vacuum pump and the working vacuum pump, damaging the two vacuum pumps.

[0007] In view of the above problems in the prior art, the present invention combines many years of design and use experience in related fields to design and manufacture a device for preventing liquid from entering a vacuum pump to overcome the above defects. Utility Model Content

[0008] In order to solve the problems existing in the prior art, the utility model provides a device for preventing liquid from entering the vacuum pump. Under the premise of not affecting the gas discharge, it prevents the liquid carried by the gas and the liquid produced by condensation from entering the working vacuum pump and the standby vacuum pump, thereby improving the service life of the two vacuum pumps.

[0009] In order to achieve the above-mentioned object, the technical solution adopted by the utility model is as follows: a device for preventing liquid from being carried inside a vacuum pump, comprising a working vacuum pump and a standby vacuum pump arranged side by side, wherein the input end of the working vacuum pump and the input end of the standby vacuum pump are respectively connected to a distillation tower via a pipeline, and the output end of the working vacuum pump and the output end of the standby vacuum pump are respectively connected to an output pipeline extending downward;

[0010] A buffer tank is provided on one side of the working vacuum pump, and the buffer tank feed port is connected to an exhaust gas pipe. The exhaust gas pipe is connected to two output pipes away from the buffer tank. The exhaust gas pipe is located below the working vacuum pump and the standby vacuum pump. An exhaust gas outlet is provided at the top of the buffer tank, and the exhaust gas outlet is connected to an exhaust gas treatment system. The position of the exhaust gas treatment system is higher than the top of the working vacuum pump and the top of the standby vacuum pump.

[0011] Preferably, a one-way valve is provided on the output pipe.

[0012] Preferably, a liquid discharge pipe is provided on the side wall of the buffer tank.

[0013] Preferably, a drain valve is provided on the liquid discharge pipe.

[0014] Preferably, the axial height of the liquid discharge pipe is lower than the axial height of the exhaust pipe.

[0015] Preferably, the top of the distillation tower is connected to an exhaust pipe, the input end of the working vacuum pump and the input end of the standby vacuum pump are respectively connected to input pipes, and the exhaust pipe and the two input pipes are connected through a three-way valve.

[0016] The benefits of this utility model are:

[0017] 1. The utility model arranges the exhaust pipe below the working vacuum pump and the standby vacuum pump, so that the gas discharged from the working vacuum pump and the liquid carried are directly discharged downward into the exhaust pipe through the output pipe. The liquid will not flow back from the exhaust pipe to the working vacuum pump and the standby vacuum pump, thereby improving the service life of the working vacuum pump and the standby vacuum pump. At the same time, a buffer tank is arranged to eliminate the height difference between the two vacuum pumps and the exhaust gas treatment system, and the gas in the exhaust pipe is discharged into the exhaust gas treatment system from the buffer tank. The exhaust pipe is arranged below the working vacuum pump and the standby vacuum pump without affecting the normal discharge of the gas to the exhaust gas treatment system. The buffer tank can relieve the pressure generated by the gas and the liquid carried, separate the gas and the liquid, and temporarily store the liquid.

[0018] 2. The utility model prevents the liquid in the buffer tank from being sucked back into the working vacuum pump by providing a one-way valve, and at the same time prevents the gas carrying the liquid from diffusing into the standby vacuum pump from the connection point between the output pipe of the standby vacuum pump and the tail gas pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is a structural diagram of a device for preventing liquid from entering a vacuum pump.

[0020] Figure 2 It is a structural schematic diagram of a gas exhaust device in the prior art.

[0021] In the figure: 1-working vacuum pump, 2-output pipe, 3-check valve, 4-exhaust pipe, 5-buffer tank, 6-exhaust outlet, 7-exhaust treatment system, 8-liquid discharge pipe, 9-drain valve, 10-distillation tower, 11-three-way valve, 12-exhaust pipe, 13-input pipe, 14-standby vacuum pump. DETAILED DESCRIPTION

[0022] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0023] like Figure 1 As shown, a device for preventing liquid carryover in a vacuum pump includes a working vacuum pump 1 and a backup vacuum pump 14 arranged side by side. The input ends of the working vacuum pump 1 and the backup vacuum pump 14 are each connected to a distillation tower 10 via a pipeline. Specifically, an exhaust pipeline 12 is connected to the top of the distillation tower 10. The input ends of the working vacuum pump 1 and the backup vacuum pump 14 are each connected to an input pipeline 13. The exhaust pipeline 12 and the two input pipelines 13 are connected via a three-way valve 11. The output ends of the working vacuum pump 1 and the backup vacuum pump 14 are each connected to a downwardly extending output pipeline 2. A one-way valve 3 is provided on the output pipeline 2.

[0024] A buffer tank 5 is provided on one side of the working vacuum pump 1. The feed port of the buffer tank 5 is connected to an exhaust gas pipe 4. The exhaust gas pipe 4 is connected to the two output pipes 2 away from the buffer tank 5. The exhaust gas pipe 4 is located below the working vacuum pump 1 and the standby vacuum pump 14. Specifically, the exhaust gas pipe 4 is a horizontally arranged pipe. An exhaust gas outlet 6 is provided at the top of the buffer tank 5, and a liquid discharge pipe 8 is provided on the side wall of the buffer tank 5. The exhaust gas outlet 6 is connected to an exhaust gas treatment system 7, and the position of the exhaust gas treatment system 7 is higher than the top of the working vacuum pump 1 and the top of the standby vacuum pump 14. The axial height of the liquid discharge pipe 8 is lower than the axial height of the exhaust pipe 4. A drain valve 9 is provided on the liquid discharge pipe 8.

[0025] In the prior art, the gas exhaust device is as follows Figure 2 As shown, the gas discharged from the output end of the working vacuum pump 1 and the liquid it carries are discharged upward into the exhaust pipe 4, and enter the exhaust gas treatment device 7 from the exhaust pipe 4. The liquid will flow back from the exhaust pipe 4 to the working vacuum pump 1 and the standby vacuum pump 14, reducing the service life of the working vacuum pump 1 and the standby vacuum pump 14.

[0026] Compared with the prior art, the present invention can eliminate the height difference between the working vacuum pump 1, the standby vacuum pump 14, and the exhaust gas treatment system 7 through the buffer tank 5. Therefore, the exhaust gas pipeline 4 is arranged below the working vacuum pump 1 and the standby vacuum pump 14 without affecting the discharge of gas into the exhaust gas treatment system 7. Specifically, the gas discharged from the output end of the working vacuum pump 1 and the liquid carried by it directly flow downward into the output pipeline 2, and then enter the buffer tank 5 through the exhaust gas pipeline 4. Since the exhaust gas pipeline 4 is located below the working vacuum pump 1 and the standby vacuum pump 14, the liquid will not flow from the exhaust gas pipeline 4 into the chamber of the working vacuum pump 1 and the standby vacuum pump 14, thereby improving the service life of the working vacuum pump 1 and the standby vacuum pump 14. In addition, the buffer tank 5 also buffers the pressure generated by the working vacuum pump 1. The gas and the liquid carried by it entering the buffer tank 5 are separated in the buffer tank 5, and the gas diffuses upward and enters the exhaust gas treatment system 7 above from the exhaust outlet 6 for further treatment. The carried liquid remains in the lower part of the buffer tank 5 under the action of gravity. The tail gas treatment system 7 is a conventional hydrocarbon compound separation device, which will not be described in detail here.

[0027] A one-way valve 3 is provided to prevent the liquid in the buffer tank 5 from being sucked back into the working vacuum pump 1. When the gas diffuses in the exhaust pipe 4, it easily diffuses upward into the standby vacuum pump 14 when passing through the connection between the output pipe 2 of the standby vacuum pump 14 and the exhaust pipe 4. The one-way valve 3 can also prevent the gas from entering the standby vacuum pump 14, thereby increasing the service life of the working vacuum pump 1 and the standby vacuum pump 14.

[0028] As the gas diffuses in the tail gas pipe 4, some of the condensed liquid flows along the tail gas pipe 4 into the buffer tank 5 and does not enter the working vacuum pump 1 and the standby vacuum pump 14. The liquid is discharged according to the liquid level in the buffer tank 5. The discharged liquid can be returned to the fractionation tower 10 for recycling. For example, the end of the liquid discharge pipe 8 away from the buffer tank 5 is connected to the fractionation tower 10. The liquid discharge pipe 8 is provided with a pump that pumps the liquid in the buffer tank 5 into the fractionation tower 10. If the axial height of the liquid discharge pipe 8 is lower than the axial height of the tail gas pipe 4, the liquid in the buffer tank 5 can be discharged in a timely manner to prevent the liquid level in the buffer tank 5 from rising above the upper end of the tail gas pipe 4, thereby obstructing gas discharge.

[0029] Specific operation process

[0030] First, after fractionating tower 10 fractionates components with a carbon content less than 9% into gas, three-way valve 11 is opened, connecting the input pipe 13 of the working vacuum pump 1 to the exhaust pipe 12. The check valve 3 on the output pipe 2 connected to the working vacuum pump 1 is opened, and the working vacuum pump 1 is started. Gas and the liquid it carries flow from the exhaust pipe 12 through the input pipe 13 into the working vacuum pump 1, then directly down into the output pipe 2, and subsequently into the exhaust pipe 4 and buffer tank 5. After the working vacuum pump 1 discharges the gas, the working vacuum pump 1 and the check valve 3 are closed. The gas and liquid entering the buffer tank 5 are separated there, with the liquid remaining in the buffer tank 5. The gas enters the exhaust gas treatment system 7 through the exhaust outlet 6 for further processing. When the liquid level in the buffer tank 5 is about to reach the lower end of the exhaust pipe 4, the drain valve 9 on the liquid discharge pipe 8 is opened to drain the liquid. During this process, the check valve 3 on the output pipe 2 of the standby vacuum pump 14 remains closed.

[0031] It should be understood that these embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention. In addition, it should be understood that after reading the technical content of the present invention, those skilled in the art may make various changes, modifications and / or variations to the present invention, and all such equivalent forms also fall within the scope of protection defined by the appended claims of this application.

Claims

1. A device for preventing liquid from entering a vacuum pump, characterized in that: The invention comprises a working vacuum pump (1) and a standby vacuum pump (14) arranged side by side, wherein the input end of the working vacuum pump (1) and the input end of the standby vacuum pump (14) are respectively connected to a fractionation tower (10) via a pipeline, and the output end of the working vacuum pump (1) and the output end of the standby vacuum pump (14) are respectively connected to an output pipeline (2) extending downward; A buffer tank (5) is provided on one side of the working vacuum pump (1), and a feed port of the buffer tank (5) is connected to a tail gas pipeline (4). The tail gas pipeline (4) is connected to two output pipelines (2) at a position away from the buffer tank (5). The tail gas pipeline (4) is located below the working vacuum pump (1) and the standby vacuum pump (14). A tail gas outlet (6) is provided at the top of the buffer tank (5), and the tail gas outlet (6) is connected to a tail gas treatment system (7). The tail gas treatment system (7) is located higher than the top of the working vacuum pump (1) and the top of the standby vacuum pump (14).

2. The device for preventing liquid from entering a vacuum pump according to claim 1, characterized in that: A one-way valve (3) is provided on the output pipe (2).

3. The device for preventing liquid from entering a vacuum pump according to claim 1, wherein: A liquid discharge pipe (8) is provided on the side wall of the buffer tank (5).

4. The device for preventing liquid from being carried inside a vacuum pump according to claim 3, characterized in that: The liquid discharge pipe (8) is provided with a liquid discharge valve (9).

5. The device for preventing liquid from being carried inside a vacuum pump according to claim 3, characterized in that: The height of the axis of the liquid discharge pipe (8) is lower than the height of the axis of the tail gas pipe (4).

6. The device for preventing liquid from entering a vacuum pump according to claim 1, characterized in that: The top of the fractionating tower (10) is connected to an exhaust pipe (12), the input end of the working vacuum pump (1) and the input end of the standby vacuum pump (14) are respectively connected to input pipes (13), and the exhaust pipe (12) and the two input pipes (13) are connected via a three-way valve (11).

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