Safe discharge and recovery system for acetaldehyde recovery waste liquid

Abstract

The invention discloses an acetaldehyde recovery waste liquid safe discharge recovery system which comprises an acetaldehyde storage tank, a nitrogen pipeline connected with a gas inlet of the acetaldehyde storage tank, a safety valve connected with a discharge port of the acetaldehyde storage tank, an esterification water storage tank used for storing waste liquid, and a water storage tank arranged between the acetaldehyde storage tank and the esterification water storage tank. An automatic water replenishing system is arranged in the water storage tank, an exhaust pipe is arranged between the safety valve and the water storage tank, a shield pump is arranged between the water storage tank and the esterification water storage tank, an inlet pipeline is arranged between the water storage tank and the shield pump, and an outlet pipeline is arranged between the shield pump and the esterification water storage tank. And the operation of an original acetaldehyde storage system can be considered, and the requirement of waste liquid recovery can be met, so that the safety of a storage environment is ensured, stable production and environmental protection are realized, and the effect of reducing the cost is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of acetaldehyde recovery technology, and in particular to a safe discharge and recovery system for acetaldehyde recovery waste liquid. Background Art

[0002] Acetaldehyde is a widely used chemical used to manufacture resins, plastics, medicines, fibers, and cosmetics, etc. It is also a common toxic chemical. When the acetaldehyde device is put into normal production and use, the safety valve seal cannot be 100% impermeable to gas and liquid, and a small amount of acetaldehyde gas will enter the accident tank (acetaldehyde storage tank) through the safety valve and cannot be collected. Moreover, when the acetaldehyde storage tank is safely discharged, the waste liquid absorbed by water in the esterification water storage tank may also cause leakage during the transportation process as the raw material of the acetaldehyde system (manual transportation), and the current discharge system is difficult to safely handle these problems. For example, the structure in the patent CN202120790561.1 is a collection and treatment device for acetaldehyde gas. Although it can solve the treatment of excess waste gas in the acetaldehyde storage tank, the acetaldehyde storage tank is sealed by nitrogen, which is essentially achieved by replacing the gas in the acetaldehyde storage tank, which consumes a lot of nitrogen and is not conducive to cost control. Therefore, it is necessary to improve the existing safety discharge system to achieve stable and safe operation of the discharge system, prevent the occurrence of environmental problems, and achieve the effect of reducing costs. Summary of the invention

[0003] In order to solve certain technical problems existing in the prior art, the purpose of this application is to provide an acetaldehyde recovery waste liquid safe discharge and recovery system, which can not only take into account the operation of the original acetaldehyde storage system, but also meet the requirements of waste liquid recovery, thereby ensuring the safety of the storage environment, thereby achieving stable production and environmental protection, and achieving the effect of reducing costs.

[0004] In order to solve the above existing technical problems, this application adopts the following technical solutions:

[0005] An acetaldehyde recovery waste liquid safe discharge recovery system comprises an acetaldehyde storage tank, a nitrogen pipeline connected to the air inlet of the acetaldehyde storage tank, a safety valve connected to the discharge port of the acetaldehyde storage tank, and an esterification water storage tank for storing waste liquid, a water storage tank is provided between the acetaldehyde storage tank and the esterification water storage tank, an automatic water replenishment system is provided in the water storage tank, an exhaust pipe is provided between the safety valve and the water storage tank, a shielded pump is provided between the water storage tank and the esterification water storage tank, an inlet pipe is provided between the water storage tank and the shielded pump, and an outlet pipe is provided between the shielded pump and the esterification water storage tank.

[0006] Preferably, the liquid level of the water storage tank is controlled between 30% and 50% by the automatic water replenishment system.

[0007] Preferably, the automatic water replenishment system includes a water replenishment pipe connecting the water source and the water storage tank, an automatic water replenishment valve arranged on the water replenishment pipe, and a liquid level sensor arranged in the water storage tank.

[0008] Preferably, the shielded pump and the liquid level sensor are controlled in linkage.

[0009] Preferably, one end of the exhaust pipe extends into the liquid in the water storage tank, and the extension length of the exhaust pipe is 80%±5% of the depth of the water storage tank.

[0010] Preferably, the nitrogen pipeline is connected to the water storage tank, a first inlet valve is provided at one end of the nitrogen pipeline connected to the water storage tank, a pressure transmitter is provided in the water storage tank, the first inlet valve is an automatic pressure regulating valve, and the opening and closing of the first inlet valve is controlled by the pressure transmitter.

[0011] Preferably, a vent pipe is provided between the water storage tank and the esterified water storage tank, and a breathing valve linked to the pressure transmitter is provided on the esterified water storage tank.

[0012] Preferably, a waste liquid outlet valve is provided at one end of the water storage tank.

[0013] Preferably, the safety valve is a spring-loaded safety valve.

[0014] Preferably, a pump inlet valve is provided on the inlet pipeline, and a pump outlet valve is provided on the outlet pipeline.

[0015] Preferably, the liquid level sensor is a magnetic flap liquid level gauge, a manual valve is provided on the water supply pipeline, and the water storage tank forms a visual liquid level storage tank through the magnetic flap liquid level gauge.

[0016] Preferably, a liquid level limit system is connected in series between the shielded pump and the liquid level sensor, and the liquid level limit system includes a manual mode and an automatic mode; the liquid level limit system includes a solenoid valve, a limit switch and a control box, the solenoid valve is arranged on the outlet pipe, the liquid level sensor and the water storage tank are vertically installed through two flanges, and the limit switch adopts two and is attached to the liquid level sensor to form a high limit and a low limit.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The water tank is connected to the safety valve through an exhaust pipe, and the safety valve is connected to the acetaldehyde tank through a pipeline. When the system pressure of the acetaldehyde tank exceeds the specified value, the safety valve automatically opens to discharge part of the gas / liquid in the acetaldehyde tank and the pipeline into the water tank through the exhaust pipe of the safety valve, so that the water and acetaldehyde gas / liquid in the tank are dissolved and diluted, and the dissolved and diluted liquid is transported to the esterification water tank as a raw material through a shielded pump, so that the pressure of the acetaldehyde tank and the pipeline does not exceed the allowable value. The safety of the acetaldehyde tank itself is protected by timely pressure relief, thereby ensuring that no production accidents occur due to excessive pressure, effectively treating acetaldehyde waste gas / waste liquid, and ensuring that the discharged gas meets environmental protection standards. Through the waste gas / waste liquid treatment system, acetaldehyde can be converted into harmless substances to reduce pollution to the environment. At the same time, the consumption of nitrogen will not increase substantially, effectively reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] In the figure: 1. acetaldehyde storage tank; 2. nitrogen pipeline; 3. first inlet valve; 4. safety valve; 5. exhaust pipe; 6. water storage tank; 7. manual valve; 8. automatic water replenishment system; 9. automatic water replenishment valve; 10. breathing valve; 11. venting pipeline; 12. water replenishment pipeline; 13. control box; 14. liquid level limit system; 15. liquid level sensor; 16. limit switch; 17. solenoid valve; 18. esterification water storage tank; 19. outlet pipeline; 20. pump outlet valve; 21. shielded pump; 22. waste liquid outlet valve; 23. pump inlet valve; 24. inlet pipeline; 25. pressure transmitter. DETAILED DESCRIPTION

[0021] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0022] In the description of the present application, it should be understood that the terms "up", "down", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0023] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0024] like Figure 1 As shown, a safe discharge and recovery system for acetaldehyde recovery waste liquid includes an acetaldehyde storage tank 1, a nitrogen pipeline 2 connected to the air inlet of the acetaldehyde storage tank 1, a safety valve 4 connected to the discharge port of the acetaldehyde storage tank 1, and an esterified water storage tank 18 for storing waste liquid, a water storage tank 6 is provided between the acetaldehyde storage tank 1 and the esterified water storage tank 18, an automatic water replenishment system 8 is provided in the water storage tank 6, an exhaust pipe 5 is provided between the safety valve 4 and the water storage tank 6, a shielded pump 21 is provided between the water storage tank 6 and the esterified water storage tank 18, an inlet pipe 24 is provided between the water storage tank 6 and the shielded pump 21, and an outlet pipe 19 is provided between the shielded pump 21 and the esterified water storage tank 18.

[0025] The volatility and toxicity of acetaldehyde make it a safety risk during the treatment process. In order to ensure the safe operation of the acetaldehyde storage tank 1, it is very important to choose a suitable safe and environmentally friendly discharge location. In actual use, the water storage tank 6 adopts an above-ground storage tank, which has low construction and maintenance costs and is easy to observe. The exterior is not corroded by the soil and has a long service life. An automatic water replenishment system 8 is equipped inside to reduce the waste of resources. A shielded pump 21 connected through an inlet pipe 24 and an outlet pipe 19 is added between the water storage tank 6 and the esterified water storage tank 18. By adding a shielded pump 21 with a liquid level limit, it can not only prevent the leakage of waste liquid during the transportation to the esterified water storage tank 18, but also ensure that no personnel intervene on site during the automatic operation, thereby ensuring the safety and reliability of the operation. Among them, the water tank 6 is connected to the safety valve 4 through the exhaust pipe 5, and the safety valve 4 is connected to the acetaldehyde storage tank 1 through a pipeline. When the system pressure of the acetaldehyde storage tank 1 exceeds the specified value, the safety valve 4 automatically opens, and the acetaldehyde storage tank 1 and part of the gas / liquid in the pipeline are discharged into the water tank 6 through the exhaust pipe 5 of the safety valve 4, so that the water and acetaldehyde gas / liquid in the tank are dissolved and diluted, and the dissolved and diluted liquid is transported to the esterification water storage tank 18 as a raw material through the shielded pump 21, so that the pressure of the acetaldehyde storage tank 1 and the pipeline does not exceed the allowable value, and the acetaldehyde storage tank 1 itself is protected by timely pressure relief, so as to ensure that no production accidents occur due to excessive pressure, effectively treat acetaldehyde waste gas / waste liquid, ensure that the discharged gas meets environmental protection standards, and through the waste gas / waste liquid treatment system, acetaldehyde can be converted into harmless substances to reduce pollution to the environment. At the same time, during the treatment process, it will not cause a large loss of nitrogen, and the consumption of nitrogen will not increase substantially, which effectively reduces the production cost and solves the problem of excessive nitrogen consumption in the prior art when the treatment is carried out by replacement.

[0026] As a further improvement, the liquid level of the water storage tank 6 is controlled between 30% and 50% by the automatic water replenishment system 8 .

[0027] Since the water storage tank 6 is an above-ground tank, the water in the tank will evaporate due to the influence of temperature and atmospheric pressure. In the previous manual operation, due to negligence or untimely operation of personnel, a large amount of water resources will often be wasted. The automatic water replenishment system 8 can automatically detect the water level in the water storage tank 6 and realize automatic water replenishment. Among them, the liquid level of the water storage tank 6 is controlled between 30% and 50% by the automatic water replenishment system 8. That is, when the liquid level is lower than 30%, the automatic water replenishment system 8 will start, so that the water in the water storage tank 6 will be maintained at the set value of 50% again and then stop. In the whole process, there is no need to arrange personnel to perform manual water replenishment operations, which improves work efficiency and protects the safety of the production process.

[0028] As a further improvement, the automatic water replenishment system 8 includes a water replenishment pipe 12 connecting the water source and the water storage tank 6 , an automatic water replenishment valve 9 arranged on the water replenishment pipe 12 , and a liquid level sensor 15 arranged in the water storage tank 6 .

[0029] The automatic water filling valve 9 and the liquid level sensor 15 are controlled in linkage. Generally, a liquid level sensor 15 is installed in the water storage tank 6, which is used to detect the height of the liquid level. When the liquid level reaches the upper liquid level sensor 15, the trigger signal closes the automatic water filling valve 9. When the liquid level reaches the lower liquid level sensor 15, the trigger signal opens the automatic water filling valve 9, thereby realizing automatic adjustment of the liquid level in the water storage tank 6, which can effectively free up the monitoring time of the operator and avoid the problem of insufficient or excessive liquid level in the water storage tank 6.

[0030] As a further improvement, the canned motor pump 21 and the liquid level sensor 15 are controlled in linkage.

[0031] Since the gas-liquid mixture discharged from the exhaust pipe 5 to the water storage tank 6 contains acetaldehyde and other gases, when it is injected into the water storage tank 6, if it is not discharged in time, it is easy to cause the problem of excessive liquid level and excessive internal pressure. Once the pressure is too high and the air tightness of the water storage tank 6 deteriorates, it is easy for air to enter the interior and cause dangers such as explosion. Therefore, it is necessary to discharge the liquid in time. When the liquid level is too low, it is easy to waste space and cause a large loss to the shielded pump 21. Therefore, it is necessary to set the shielded pump 21 to start and stop reasonably, wherein the start and stop liquid level range of the shielded pump 21 is 35% to 80%. When the liquid level sensor 15 detects that the liquid level in the water storage tank 6 reaches 80%, the shielded pump 21 is started to discharge liquid into the esterified water storage tank 18. When the discharge reaches 35% of the liquid level, the shielded pump 21 stops working, thereby effectively controlling the internal liquid level, avoiding excessive internal pressure or overflow, and avoiding directly triggering the start of the automatic water replenishment system 8.

[0032] A further improvement is that one end of the exhaust pipe 5 extends into the liquid in the water storage tank 6 , and the extending length of the exhaust pipe 5 is 80%±5% of the depth of the water storage tank 6 .

[0033] One end of the exhaust pipe 5 extends into the liquid in the water tank 6, so that the gas-liquid mixture containing acetaldehyde discharged through the exhaust pipe 5 can be directly mixed with the water in the water tank 6, so that the water in the tank and the acetaldehyde gas / liquid are dissolved and diluted, thereby achieving the purpose of effectively treating the acetaldehyde waste gas / waste liquid and ensuring that the discharged gas meets environmental protection standards. Among them, the extension length of the exhaust pipe 5 is about 80% of the depth of the water tank 6, which can effectively ensure that the acetaldehyde liquid is always injected into the water and will not directly contact with the air, thereby improving the overall safety.

[0034] A further improvement is that the nitrogen pipeline 2 is connected to the water storage tank 6, one end of the nitrogen pipeline 2 connected to the water storage tank 6 is provided with a first inlet valve 3, a pressure transmitter 25 is provided in the water storage tank 6, the first inlet valve 3 is an automatic pressure regulating valve, and the opening and closing of the first inlet valve 3 is controlled by the pressure transmitter 25.

[0035] The nitrogen pipeline 2 can be used to inject nitrogen seal into the unfilled space in the water storage tank 6, thereby protecting the water storage tank 6 and preventing oxygen from entering the water storage tank 6 and contacting with acetaldehyde to cause explosion, which is safer. A first inlet valve 3 is installed on the nitrogen pipeline 2. The first inlet valve 3 on the nitrogen pipeline 2 is an automatic regulating valve. When the pressure in the water storage tank 6 is lower than 20Kpa, the pressure transmitter 25 is used to open the first inlet valve 3 to supplement the nitrogen seal, and when it reaches 25Kpa, the first inlet valve 3 is controlled to close and stop the nitrogen seal supplement.

[0036] As a further improvement, a vent pipe 11 is provided between the water storage tank 6 and the esterified water storage tank 18 , and a breathing valve 10 linked to the pressure transmitter 25 is provided on the esterified water storage tank 18 .

[0037] Among them, the opening pressure of the breathing valve 10 is 30Kpa. When the pressure in the water tank 6 increases abnormally, in order to ensure the safety of the water tank 6, the breathing valve 10 can be automatically opened to discharge the exhaust gas into the esterification water tank 18 for pressure relief to avoid the occurrence of safety accidents. At the same time, when the temperature is higher than 21 degrees, acetaldehyde will be vaporized. At this time, the vaporized acetaldehyde can be directly discharged into the esterification water tank 18 through the vent pipe 11 to avoid environmental pollution.

[0038] As a further improvement, a waste liquid outlet valve 22 is provided at one end of the water storage tank 6 .

[0039] The waste liquid outlet valve 22 is generally normally closed and will be opened when the water storage tank 6 needs to be cleaned, thereby facilitating the cleaning of the inside of the water storage tank 6.

[0040] A further improvement is that the safety valve 4 is a spring-type safety valve 4 .

[0041] The safety valve 4 adopts a spring-type safety valve 4, which is easy to adjust, smaller in size and weight, and has a large steam exhaust capacity.

[0042] As a further improvement, a pump inlet valve 23 is provided on the inlet pipe 24 , and a pump outlet valve 20 is provided on the outlet pipe 19 .

[0043] The pump inlet valve 23 and the pump outlet valve 20 are usually in an open state, which is convenient for the automatic opening of the shielded pump 21, and the degree of automation is high. When the shielded pump 21 is damaged, maintenance is more convenient.

[0044] As a further improvement, the liquid level sensor 15 adopts a magnetic flap liquid level gauge, a manual valve 7 is provided on the water supply pipe 12, and the water storage tank 6 forms a visible liquid level storage tank through the magnetic flap liquid level gauge.

[0045] When the automatic water replenishment valve 9 is damaged, if it is not discovered in time, the liquid level in the water tank 6 will not be properly controlled, resulting in too much or too little problems. When the liquid level in the tank is too high, it will cause a safety accident of overflowing the tank, and if it is too little, it will not be effective. Therefore, the liquid level sensor 15 on one side of the water tank 6 adopts a magnetic flap liquid level gauge. The combination of the magnetic flap liquid level gauge and the manual valve 7 can help the operator to grasp the height of the liquid level, so as to take control measures in time to ensure the stability and efficient operation of the production process and avoid the occurrence of dangerous situations.

[0046] A further improvement is that a liquid level limit system 14 is connected in series between the shielded pump 21 and the liquid level sensor 15, and the liquid level limit system 14 includes a manual mode and an automatic mode; the liquid level limit system 14 includes a solenoid valve 17, a limit switch 16 and a control box 13, the solenoid valve 17 is arranged on the outlet pipe 19, the liquid level sensor 15 and the water storage tank 6 are vertically installed through two flanges, and the limit switch 16 adopts two and is attached to the liquid level sensor 15 to form a high limit and a low limit.

[0047] In actual use, the solenoid valve 17 is installed on the outlet pipe 19, the liquid level sensor 15 is installed on the two flanges on the side of the water tank 6 and installed vertically, the limit switch 16 uses two and is attached to the liquid level sensor 15 to form a high limit and a low limit, and the control box 13 is on the open space on the side. Working principle: the high limit switch 16 is a normally closed contact, and the low limit switch 16 is a normally open contact. After power on, the 220V AC is converted into 24V DC through the switching power supply. In the automatic mode of the control box 13, when the liquid level reaches the low limit, the normally open contact of the low limit switch 16 is closed, the relay coil is energized, and the normally open contact of the relay is closed to form a self-locking, and the solenoid valve 17 is opened for water replenishment. When the liquid level reaches the high limit, the normally closed contact of the high limit switch 16 is disconnected, the relay coil loses power, and the solenoid valve 17 is closed to stop water replenishment. This cycle is repeated. In the manual mode of the control box 13, the switch of the solenoid valve 17 can be controlled by the start and stop buttons.

[0048] The above-mentioned implementation modes are only preferred implementation modes of the present application and cannot be used to limit the scope of protection of the present application. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present application shall fall within the scope of protection required by the present application.

Claims

1. An acetaldehyde recovery waste liquid safe discharge recovery system, comprising an acetaldehyde storage tank (1), a nitrogen pipeline (2) connected to the air inlet of the acetaldehyde storage tank (1), a safety valve (4) connected to the discharge port of the acetaldehyde storage tank (1), and an esterification water storage tank (18) for storing waste liquid, characterized in that: A water storage tank (6) is provided between the acetaldehyde storage tank (1) and the esterified water storage tank (18), an automatic water replenishment system (8) is provided in the water storage tank (6), an exhaust pipe (5) is provided between the safety valve (4) and the water storage tank (6), a shielded pump (21) is provided between the water storage tank (6) and the esterified water storage tank (18), an inlet pipe (24) is provided between the water storage tank (6) and the shielded pump (21), and an outlet pipe (19) is provided between the shielded pump (21) and the esterified water storage tank (18).

2. The acetaldehyde recovery waste liquid safe discharge and recovery system according to claim 1, characterized in that: The automatic water replenishment system (8) comprises a water replenishment pipe (12) connecting a water source and the water storage tank (6), an automatic water replenishment valve (9) arranged on the water replenishment pipe (12), and a liquid level sensor (15) arranged in the water storage tank (6).

3. The acetaldehyde recovery waste liquid safe discharge and recovery system according to claim 2, characterized in that: The shielded pump (21) and the liquid level sensor (15) are controlled in linkage.

4. The acetaldehyde recovery waste liquid safe discharge and recovery system according to claim 1, characterized in that: One end of the exhaust pipe (5) extends into the liquid in the water storage tank (6), and the extension length of the exhaust pipe (5) is 80%±5% of the depth of the water storage tank (6).

5. A safe discharge and recovery system for acetaldehyde recovery waste liquid according to any one of claims 1 to 4, characterized in that: The nitrogen pipeline (2) is in communication with the water storage tank (6); a first inlet valve (3) is provided at one end of the nitrogen pipeline (2) in communication with the water storage tank (6); a pressure transmitter (25) is provided in the water storage tank (6); the first inlet valve (3) is an automatic pressure regulating valve; the opening and closing of the first inlet valve (3) is controlled by the pressure transmitter (25).

6. The acetaldehyde recovery waste liquid safe discharge and recovery system according to claim 5, characterized in that: A vent pipe (11) is also provided between the water storage tank (6) and the esterified water storage tank (18), and a breathing valve (10) linked to the pressure transmitter (25) is provided on the esterified water storage tank (18).

7. The acetaldehyde recovery waste liquid safe discharge and recovery system according to claim 1, characterized in that: The safety valve (4) is a spring-type safety valve (4).

8. The acetaldehyde recovery waste liquid safe discharge and recovery system according to claim 3, characterized in that: The inlet pipe (24) is provided with a pump inlet valve (23), and the outlet pipe (19) is provided with a pump outlet valve (20).

9. The acetaldehyde recovery waste liquid safe discharge and recovery system according to claim 1, characterized in that: The liquid level sensor (15) is a magnetic flap liquid level gauge, a manual valve (7) is provided on the water supply pipeline (12), and the water storage tank (6) forms a visible liquid level storage tank through the magnetic flap liquid level gauge.

10. The acetaldehyde recovery waste liquid safe discharge and recovery system according to claim 9, characterized in that: A liquid level limit system (14) is connected in series between the canned pump (21) and the liquid level sensor (15), and the liquid level limit system (14) includes a manual mode and an automatic mode; the liquid level limit system (14) includes a solenoid valve (17), a limit switch (16) and a control box (13), the solenoid valve (17) is arranged on the outlet pipe (19), the liquid level sensor (15) and the water storage tank (6) are vertically installed via two flanges, and the limit switch (16) is formed of two and attached to the liquid level sensor (15) to form a high limit and a low limit.

Images