A waste solvent online automatic discharge system

Abstract

The utility model relates to an online automatic discharge system for waste solvents, including a pre-pump cold trap, a pre-pump condensate tank and a nitrogen supply system, wherein the outlet end of the pre-pump cold trap is connected to a first liquid outlet pipeline, and the first liquid outlet pipeline is provided with a first liquid outlet valve assembly; the pre-pump condensate tank is connected to the first liquid outlet pipeline, and the outlet end of the pre-pump condensate tank is connected to a second liquid outlet pipeline, and the second liquid outlet pipeline is provided with a second liquid outlet valve assembly and a material transfer pump; the nitrogen supply system includes a nitrogen supply pipeline connected to the pre-pump condensate tank, and the nitrogen supply pipeline is connected to a self-powered nitrogen supply valve and a nitrogen replenishment valve close to the pre-pump condensate tank. The online automatic discharge system for waste solvents provided by the utility model can realize the operation of directly discharging waste liquid without stopping the vacuum unit, solve the problem that the waste solvent in the pre-pump cold trap cannot be transferred away by the material transfer pump due to negative pressure when the vacuum unit is running, and avoid the failure caused by the idling of the material transfer pump.

Description

Technical Field

[0001] The utility model relates to the technical field of waste liquid recovery, in particular to an online automatic discharge system for waste solvents. Background Art

[0002] In the past, the waste solvent discharge system before the pump in the production workshop usually consists of a cold trap before the pump and a transfer pump, which is simple in structure and time-consuming and labor-intensive. Every time the waste solvent is discharged, the operator needs to observe the liquid level of the cold trap through a sight glass to determine whether it needs to be discharged. If discharge is required, the vacuum unit needs to be shut down and the transfer pump needs to be connected separately on site, which seriously affects production efficiency. If the discharge is not timely, the waste solvent will flow into the pump cavity, which will damage the vacuum unit and affect the normal operation of the equipment.

[0003] In order to improve this situation and discharge the waste solvent without stopping the machine, the waste solvent discharge system was upgraded. Since the cold trap is under negative pressure when the vacuum unit is running, the gear pump and liquid level gauge suitable for negative pressure conditions are interlocked. During use, it was found that the pipeline from the cold trap to the gear pump was too long and it was difficult to drain the liquid. When the vacuum unit was running, due to the low viscosity of the solvent and the negative pressure, the waste solvent could not flow into the pipeline by gravity. When the liquid level of the cold trap reached the upper limit of the discharge, the gear pump started. Since the negative pressure formed at the inlet of the gear pump was much smaller than that inside the cold trap, the liquid could not be pumped into the gear pump, causing the gear pump to run idle for a long time and make abnormal noises, which could easily cause equipment damage. Utility Model Content

[0004] The purpose of the utility model is to provide an online automatic waste solvent discharge system, which can solve the technical problems mentioned in the above background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: an online automatic discharge system for waste solvents, comprising a pre-pump cold trap, a pre-pump condensate tank and a nitrogen supply system, wherein the outlet end of the pre-pump cold trap is connected to a first liquid outlet pipeline, and the first liquid outlet pipeline is provided with a first liquid outlet valve assembly; a pre-pump condensate tank is connected to the first liquid outlet pipeline, and the outlet end of the pre-pump condensate tank is connected to a second liquid outlet pipeline, and the second liquid outlet pipeline is provided with a second liquid outlet valve assembly and a material transfer pump; a nitrogen supply system, comprising a nitrogen supply pipeline connected to the pre-pump condensate tank, and the nitrogen supply pipeline is connected to a self-powered nitrogen supply valve and a nitrogen replenishment valve close to the pre-pump condensate tank.

[0006] In one embodiment, the nitrogen supply pipeline is also connected to a pressure gauge, which is arranged at the rear end of the self-operated nitrogen supply valve and is used for nitrogen supply pressure detection to ensure that the pressure in the condensate tank before the pump is appropriate.

[0007] In one embodiment, the pre-pump condensate tank is also connected to a liquid level sensor for real-time detection of the liquid level in the pre-pump condensate tank.

[0008] In one embodiment, the transfer pump adopts an air-driven diaphragm pump. By adopting an air-driven diaphragm pump instead of a traditional gear pump with low suction force, it is possible to avoid the situation where the waste solvent cannot be discharged through the pump due to negative pressure difference, thereby causing the pump to run idle.

[0009] In one embodiment, the first liquid outlet valve assembly includes a first hand valve close to the cold trap end before the pump and a first pneumatic switch valve arranged at the rear end of the first hand valve.

[0010] In one embodiment, the second liquid outlet valve assembly includes a second manual valve close to the front condensate tank of the pump and a second pneumatic switch valve arranged at the rear end of the second manual valve.

[0011] In one embodiment, the pre-pump condensate tank is disposed below the pre-pump cold trap, so that the waste solvent in the pre-pump cold trap can automatically flow into the pre-pump condensate tank by gravity, thereby saving energy consumption.

[0012] In one embodiment, the pre-pump cold trap and the pre-pump condensate tank connected thereto are arranged in multiple groups, and each pre-pump condensate tank shares the same nitrogen supply pipeline and the second liquid outlet pipeline.

[0013] In one embodiment, the nitrogen supply pipeline is connected to the pre-pump condensate tank via nitrogen branch pipelines, and the pre-pump condensate tank is connected to the second liquid outlet pipeline via liquid outlet branch pipelines, to ensure that the discharge operations do not affect each other.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The waste solvent online automatic discharge system provided by the utility model can realize the operation of directly discharging waste solvent without stopping the vacuum unit, by adding a pre-pump condensate tank between the pre-pump cold trap and the transfer pump, and controlling the connection between the pre-pump cold trap and the pre-pump condensate tank through the first liquid outlet valve assembly, connecting the pre-pump condensate tank with a nitrogen supply system, and replenishing the pre-pump condensate tank with a slight positive pressure to offset the negative pressure during discharge, effectively solving the problem that the waste solvent in the pre-pump cold trap cannot be transferred away by the transfer pump due to negative pressure during the operation of the vacuum unit, and avoiding the failure caused by the idling of the transfer pump. Further, by setting the upper limit value and alarm value of automatic liquid discharge, the waste solvent can be discharged in time to avoid entering the vacuum pump cavity and damaging the equipment, and can also prevent equipment abnormalities caused by the continuous rise of the liquid level. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of an online automatic waste solvent discharge system provided in an embodiment of the utility model.

[0017] The meaning of each number in the figure is:

[0018] 1. Cold trap before the pump; 2. First liquid outlet pipeline; 3. Condensate tank before the pump; 4. Second liquid outlet pipeline; 41. Liquid outlet branch pipeline; 5. Transfer pump; 6. Vacuum unit; 7. First liquid outlet valve assembly; 71. First manual valve; 72. First pneumatic switch valve; 8. Nitrogen supply pipeline; 81. Nitrogen branch pipeline; 9. Self-operated nitrogen supply valve; 10. Nitrogen replenishment valve; 11. Pressure gauge; 12. Liquid level sensor; 13. Second liquid outlet valve assembly; 131. Second manual valve; 132. Second pneumatic switch valve. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, 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 the present invention.

[0021] See also Figure 1 This embodiment discloses an online automatic discharge system for waste solvents, including a pre-pump cold trap 1, the outlet end of the pre-pump cold trap 1 is connected to a pre-pump condensate tank 3 through a first liquid outlet pipeline 2, the outlet end of the pre-pump condensate tank 3 is connected to a second liquid outlet pipeline 4, the second liquid outlet pipeline 4 is connected to a transfer pump 5, and the waste liquid in the second liquid outlet pipeline 4 is transferred by the transfer pump 5 for environmental protection treatment. The pre-pump condensate tank 3 is also connected to a nitrogen supply system, which is used to supply nitrogen to the pre-pump condensate tank 3.

[0022] Specifically, the pre-pump cold trap 1 is respectively connected to a vacuum unit 6, a nitrogen pipeline and a cooling jacket, and is used for condensing, collecting and temporarily storing the waste solvent in a gaseous state.

[0023] The pre-pump condensate tank 3 is arranged below the pre-pump cold trap 1, so that the waste solvent in the pre-pump cold trap 1 can automatically flow into the pre-pump condensate tank 3 by gravity. The outlet end of the pre-pump cold trap 1 is provided with a flange port, through which the first liquid outlet pipeline 2 is connected. The first liquid outlet pipeline 2 is provided with a first liquid outlet valve assembly 7, which is used to control the flow rate or on-off of the first liquid outlet pipeline 2. In this embodiment, the pre-pump condensate tank 3 can also be used for temporary storage of waste solvent. When the automatic liquid discharge operation is performed, the first liquid outlet valve assembly 7 is closed, which does not affect the use of the vacuum unit 6 and the pre-pump cold trap 1.

[0024] In other embodiments not shown, the positions of the pre-pump condensate tank 3 and the pre-pump cold trap 1 may also be set according to actual workshop conditions, and the transfer of the waste solvent may be controlled by the pump body.

[0025] Preferably, to prevent the valve group from being damaged, the first liquid outlet valve assembly 7 includes a first hand valve 71 near the end of the cold trap 1 in front of the pump and a first pneumatic switch valve 72 arranged at the rear end of the first hand valve 71. When the first pneumatic switch valve 72 is abnormal, the first hand valve 71 can be used to timely cut off the first liquid outlet pipeline 2. During the operation of the equipment, the first hand valve 71 and the first pneumatic switch valve 72 should be kept normally open.

[0026] The nitrogen supply system includes a nitrogen supply pipeline 8 and a nitrogen source connected to one end of the nitrogen supply pipeline 8. The other end of the nitrogen supply pipeline 8 is connected to the pre-pump condensate tank 3, which is used to replenish nitrogen into the pre-pump condensate tank 3 so that it is maintained in a slightly positive pressure state during liquid discharge. The nitrogen supply pipeline 8 is connected to a self-operated nitrogen supply valve 9 on the side close to the nitrogen source, and the self-operated nitrogen supply valve 9 is used for flow control and pressure control of the pipeline; the nitrogen supply pipeline 8 is connected to a nitrogen replenishment valve 10 for on-off control on the side close to the pre-pump condensate tank 3. The nitrogen supply system can replenish nitrogen into the pre-pump condensate tank 3 so that it maintains a slightly positive pressure in the liquid discharge state, ensuring smooth liquid discharge. At the same time, the system is always in a nitrogen protection state during the operation process, which largely ensures the safety of the system.

[0027] Preferably, the nitrogen supply pipeline 8 is also connected to a pressure gauge 11, which is arranged at the rear end of the self-operated nitrogen supply valve 9 and is used for nitrogen supply pressure detection to ensure that the pressure in the pre-pump condensate tank 3 is appropriate.

[0028] In this embodiment, the first liquid outlet pipeline 2 and the nitrogen supply pipeline 8 are connected to the pre-pump condensate tank 3 through separate pipelines, which can prevent gas-liquid cross-flow and make the equipment more reliable and stable.

[0029] like Figure 1As shown, the pre-pump condensate tank 3 is also connected to a liquid level sensor 12 with a remote transmission function, which is used for real-time detection of the liquid level in the pre-pump condensate tank 3. The upper limit and lower limit of the liquid level are preset, the upper limit is the automatic drainage setting value of the pre-pump condensate tank 3, the lower limit is the minimum volume of the pre-pump condensate tank 3, and the lower limit is the setting value for stopping the automatic drainage. It is judged whether the pre-pump condensate tank 3 reaches the drainage condition according to the liquid level detection value. Preferably, the liquid level gauge alarm value can also be preset. When the automatic drainage system fails, as the liquid level in the pre-pump condensate tank 3 rises, the alarm setting value is triggered, which can remind the staff to deal with the abnormality in time.

[0030] Continue to see Figure 1 The outlet end of the pre-pump condensate tank 3 is connected to a second liquid outlet pipeline 4, and a second liquid outlet valve assembly 13 is provided on the second liquid outlet pipeline 4 to control the flow rate or on-off of the second liquid outlet pipeline 4. Preferably, the second liquid outlet valve assembly 13 includes a second hand valve 131 close to the pre-pump condensate tank 3 and a second pneumatic switch valve 132 arranged at the rear end of the second hand valve 131.

[0031] Exemplarily, during normal operation, the first liquid outlet valve assembly 7 is opened, the self-operated nitrogen supply valve 9 and the nitrogen replenishment valve 10 are closed, the cold trap 1 before the pump condenses and collects the waste solvent, and transfers it to the condensate tank 3 before the pump through the first liquid outlet pipeline 2. When the liquid level of the condensate tank 3 before the pump reaches the set upper limit value, the first liquid outlet valve assembly 7 is closed, the connection between the cold trap 1 before the pump and the condensate tank 3 before the pump is cut off, and the nitrogen replenishment valve 10 is opened. At this time, the pressure in the condensate tank 3 before the pump is lower than 1Kpa, the self-operated nitrogen supply valve 9 is opened, and the system is maintained at a slight positive pressure. When the pressure reaches the target value, the self-operated nitrogen supply valve 9 is closed, so that the pressure in the condensate tank 3 before the pump is always in a slight positive pressure state. Then open the second liquid outlet valve assembly 13, and turn on the transfer pump 5 to discharge the waste solvent to the temporary storage tank of the environmental protection treatment center. When the liquid level of the pre-pump condensate tank 3 reaches the set lower limit, the second liquid outlet valve assembly 13, the material transfer pump 5 and the nitrogen replenishment valve 10 are closed, and the first liquid outlet valve assembly 7 is opened to restore the system to its initial state.

[0032] In a preferred embodiment, the material transfer pump 5 adopts a pneumatic diaphragm pump, and a solenoid valve is installed at the driving air source of the pneumatic diaphragm pump. By adopting a pneumatic diaphragm pump instead of a traditional gear pump with low suction force, it is possible to avoid the situation where the waste solvent cannot be discharged through the pump due to negative pressure difference, thereby causing the pump to run idle, thereby effectively reducing the frequency of equipment failures and improving operating efficiency.

[0033] In another preferred embodiment, the pre-pump cold trap 1 and the pre-pump condensate tank 3 connected thereto are arranged in multiple groups according to the actual workload, and each pre-pump condensate tank 3 shares the same nitrogen supply pipeline 8 and the second liquid outlet pipeline 4, and the nitrogen supply pipeline 8 is connected to the pre-pump condensate tank 3 through a nitrogen branch pipeline 81, and each nitrogen branch pipeline 81 is respectively provided with a nitrogen replenishment valve 10; similarly, each pre-pump condensate tank 3 is connected to the second liquid outlet pipeline 4 through a liquid outlet branch pipeline 41, and each liquid outlet branch pipeline 41 is respectively provided with a second liquid outlet valve assembly 13, so as to achieve mutual non-influence during the discharge operation.

[0034] It can be understood that the online automatic discharge system for waste solvents provided in this embodiment also includes an automatic control system. The automatic control system adopts a DCS control system, which can perform logical program editing according to actual needs. By real-time monitoring or logical judgment of the liquid level meter value, the first pneumatic switch valve 72, the second pneumatic switch valve 132, the nitrogen supply system, and the pneumatic diaphragm pump, etc., it can realize automatic program control of each valve and pump body, thereby realizing the full process operation of waste solvent collection, transfer, and discharge.

[0035] The waste solvent online automatic discharge system provided in the present embodiment can realize the operation of directly discharging waste liquid without stopping the vacuum unit 6. In the present embodiment, a pre-pump condensate tank 3 is added between the pre-pump cold trap 1 and the material transfer pump 5, and the connection between the pre-pump cold trap 1 and the pre-pump condensate tank 3 is controlled by the first liquid outlet valve assembly 7, and the pre-pump condensate tank 3 is connected to the nitrogen supply system. When discharging, the pre-pump condensate tank 3 is replenished with a slight positive pressure through the nitrogen supply system to offset the negative pressure, which effectively solves the problem that the waste solvent in the pre-pump cold trap 1 cannot be transferred away by the material transfer pump 5 due to the negative pressure when the vacuum unit 6 is running, and at the same time avoids the malfunction caused by the idling of the material transfer pump 5.

[0036] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the utility model and are not used to limit the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A waste solvent online automatic discharge system, characterized in that: include: A pre-pump cold trap (1), wherein the outlet end of the pre-pump cold trap (1) is connected to a first liquid outlet pipeline (2), and the first liquid outlet pipeline (2) is provided with a first liquid outlet valve assembly (7); A pre-pump condensate tank (3) is connected to the first liquid outlet pipeline (2); the outlet end of the pre-pump condensate tank (3) is connected to a second liquid outlet pipeline (4); the second liquid outlet pipeline (4) is provided with a second liquid outlet valve assembly (13) and a material transfer pump (5); The nitrogen supply system comprises a nitrogen supply pipeline (8) connected to a pre-pump condensate tank (3), wherein the nitrogen supply pipeline (8) is connected to a self-operated nitrogen supply valve (9) and a nitrogen replenishment valve (10) close to the pre-pump condensate tank (3).

2. The waste solvent online automatic discharge system according to claim 1, characterized in that: The nitrogen supply pipeline (8) is also connected to a pressure gauge (11), and the pressure gauge (11) is arranged at the rear end of the self-operated nitrogen supply valve (9).

3. The waste solvent online automatic discharge system according to claim 1, characterized in that: The pre-pump condensate tank (3) is also connected to a liquid level sensor (12).

4. The waste solvent online automatic discharge system according to claim 1, characterized in that: The material transfer pump (5) is a pneumatic diaphragm pump.

5. The waste solvent online automatic discharge system according to claim 1, characterized in that: The first liquid outlet valve assembly (7) comprises a first hand valve (71) close to the end of the cold trap (1) in front of the pump and a first pneumatic switch valve (72) arranged at the rear end of the first hand valve (71).

6. The waste solvent online automatic discharge system according to claim 1, characterized in that: The second liquid outlet valve assembly (13) comprises a second hand valve (131) close to the front condensate tank (3) of the pump and a second pneumatic switch valve (132) arranged at the rear end of the second hand valve (131).

7. The waste solvent online automatic discharge system according to claim 1, characterized in that: The pre-pump condensate tank (3) is arranged below the pre-pump cold trap (1).

8. The waste solvent online automatic discharge system according to claim 1, characterized in that: The pre-pump cold trap (1) and the pre-pump condensate tank (3) connected thereto are arranged in multiple groups, and each pre-pump condensate tank (3) shares the same nitrogen supply pipeline (8) and the second liquid outlet pipeline (4).

9. The waste solvent online automatic discharge system according to claim 8, characterized in that: The nitrogen supply pipeline (8) is connected to the pre-pump condensate tank (3) through nitrogen branch pipelines (81), and the pre-pump condensate tank (3) is connected to the second liquid outlet pipeline (4) through liquid outlet branch pipelines (41).

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