An organic liquid purification and recovery device and method

Abstract

The present invention discloses an organic liquid purification and recovery device, which includes a distillation kettle and a receiving tank connected by a distillation pipe. The device further includes a vacuum pump. A vacuum storage tank is arranged between the receiving tank and the vacuum pump. The vacuum storage tank is connected to the receiving tank through a vacuum adjustment pipe, and a first vacuum adjustment valve is arranged on the vacuum adjustment pipe. The vacuum storage tank is connected to the vacuum pump through a vacuum extraction pipe, and a second vacuum adjustment valve is arranged on the vacuum extraction pipe. In the present invention, a vacuum storage tank is arranged between the receiving tank and the vacuum pump, and the vacuum degree of the receiving tank is adjusted by the vacuum storage tank, so as to realize the recovery of organic liquid in a reduced-pressure and airtight environment. The vacuum pump is intermittently started instead of continuously working, which avoids the vacuum pump directly and continuously evacuating the system, thereby avoiding the situation that the organic liquid is evacuated by the continuous vacuum pumping of the vacuum pump, resulting in waste of organic liquid and environmental pollution.

Description

Technical Field

[0001] The present invention relates to a device and method for purifying and recycling organic liquids, which can be applied to the fields of organic chemical industry and pharmaceutical chemical industry. Background Art

[0002] At present, the organic chemical industry and pharmaceutical chemical industry cause great environmental pollution due to the problems of three wastes. Especially when recycling organic solvents, due to the use of vacuum, the volatility of the solvents is relatively large, so the volatilization of organic solvents inevitably causes environmental pollution. Many engineers are committed to solving this problem. Currently, the more commonly used methods are as follows: A: Absorbing the tail gas with activated carbon and activated fibers; B: Adopting the method of cryogenic or multi-stage cooling; C: Neutralizing the tail gas and then discharging it to the wastewater treatment system for treatment. Among them, method A requires high-temperature desorption, with cumbersome operation steps and high investment; the multi-stage cooling effect of method B is limited, and if cryogenic cooling is used, a large amount of liquid nitrogen is required, which is not convenient for industrial production; method C has great limitations and cannot be used for those insoluble in water, and after being dissolved in water, the generated wastewater requires a supporting biochemical treatment system. Currently, the recovery rate of organic solvents is between 60% and 80%. The lower the boiling point, the greater the volatility and the lower the recovery rate. For example, the recovery rates of chloroform and ethyl acetate are generally about 70%. This means that 30% of the solvents are discharged into the atmosphere as unorganized waste gas and cannot be recovered, which not only wastes resources but also pollutes the environment. According to statistics, the annual emissions of organic waste gas are approximately in the tens of millions of tons level. Therefore, we urgently need a simple and feasible method to improve the recovery rate of organic solvents, reduce the environmental pollution caused by organic waste gas, and achieve the green recycling of organic liquids. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a device and method for purifying and recycling organic liquids that are safe, environmentally friendly, have a high recovery rate, produce less waste gas, and are energy-saving.

[0004] To solve the above technical problem, the present invention first discloses a device for purifying and recycling organic liquids, including a distillation kettle and a receiving tank connected by a distillation pipe. The device further includes a vacuum pump. A vacuum storage tank is arranged between the receiving tank and the vacuum pump. The vacuum storage tank is connected to the receiving tank through a vacuum adjustment pipe, and a first vacuum adjustment valve is arranged on the vacuum adjustment pipe. The vacuum storage tank is connected to the vacuum pump through a vacuum extraction pipe, and a second vacuum adjustment valve is arranged on the vacuum extraction pipe; the distillation kettle is provided with a temperature monitoring device and a pressure monitoring device, and the receiving tank and the vacuum storage tank are both provided with pressure monitoring devices.

[0005] Furthermore, the vacuum storage tank can be provided with a condensation device to improve the recovery rate. The condensation device can adopt internal condensation or external condensation, etc. Internal condensation is such as an internal circulation coil, and external condensation is such as arranging a jacket outside the vacuum storage tank.

[0006] Further, the temperature monitoring device, the pressure monitoring device, the first vacuum regulating valve, the second vacuum regulating valve, and the vacuum pump are all connected to the intelligent controller through control lines.

[0007] Further, a cooling device is provided outside the distillation kettle. The cooling water pipe and the steam pipe of the cooling device are provided with automatic control valves, and the automatic control valves are connected to the intelligent controller through control lines.

[0008] Further, the intelligent controller includes a vacuum regulation controller and a safety controller. The pressure monitoring devices of the first vacuum regulating valve, the second vacuum regulating valve, and the vacuum storage tank are connected to the vacuum regulation controller; the temperature monitoring device, the pressure monitoring device of the distillation kettle, the pressure monitoring device of the receiving tank, and the automatic control valves of the cooling device are connected to the safety controller through control lines.

[0009] The present invention also discloses a method for purifying and recovering organic liquids using the aforementioned device. The purification and recovery method includes:

[0010] 1), Input the liquid to be treated into the distillation kettle;

[0011] 2), Disconnect the connection between the vacuum storage tank and the receiving tank, turn on the vacuum pump to evacuate the vacuum storage tank to a predetermined value, then turn off the vacuum pump, and disconnect the connection between the vacuum pump and the vacuum storage tank;

[0012] 3), Open the connection between the vacuum storage tank and the receiving tank, and the organic liquid distills into the receiving tank;

[0013] 4), When the vacuum in the vacuum storage tank is insufficient, sequentially repeat steps 2) and 3);

[0014] 5), Repeat step 4) several times until no more liquid distills out.

[0015] During this treatment process, after the liquid to be treated is input into the distillation kettle in step 1), it can be heated to reach the set value. In step 3), first, the temperature in the distillation kettle is stabilized at the set value, and then the vacuum storage tank is slowly opened to evacuate and distill the receiving tank.

[0016] Further, the purification and recovery process is controlled by an intelligent controller. The vacuum regulation controller of the intelligent controller monitors the pressure in the vacuum storage tank and controls the opening and closing of the first vacuum regulating valve, the second vacuum regulating valve, and the vacuum pump; the safety controller of the intelligent controller monitors the pressure in the receiving tank, the pressure and temperature in the distillation kettle, controls the opening and closing of the cooling device and the stirring device of the distillation kettle, and gives an alarm when necessary.

[0017] The process of the method for purifying and recovering organic liquids using the aforementioned device of the present invention can also be:

[0018] 1), Open the connection between the receiving tank and the vacuum storage tank, and the connection between the vacuum storage tank and the vacuum pump. Then turn on the vacuum pump to evacuate the system to a preset value, and then turn off the vacuum pump and disconnect the vacuum pump from the vacuum storage tank.

[0019] 2), Continuously input the liquid to be processed into the distillation kettle, and the organic liquid distills into the receiving tank.

[0020] 3), When the vacuum in the vacuum storage tank is insufficient, disconnect the connection between the vacuum storage tank and the receiving tank, open the connection between the vacuum storage tank and the vacuum pump, turn on the vacuum pump to evacuate the vacuum storage tank to a preset value, then turn off the vacuum pump and disconnect the vacuum storage tank from the vacuum pump. Then open the connection between the vacuum storage tank and the receiving tank to continue distilling the liquid.

[0021] 4), Repeat step 4) several times until no more liquid distills.

[0022] Furthermore, before step 1), the distillation kettle, and before step 2), the liquid to be processed input into the distillation kettle are both preheated to a predetermined value.

[0023] Furthermore, the purification and recovery process is controlled by an intelligent controller. The vacuum adjustment controller of the intelligent controller monitors the pressure in the vacuum storage tank and controls the opening and closing of the first vacuum regulating valve, the second vacuum regulating valve, and the vacuum pump. The safety controller of the intelligent controller monitors the pressure in the receiving tank, the pressure and temperature in the distillation kettle, controls the opening and closing of the cooling device and the stirring device of the distillation kettle, and gives an alarm when necessary.

[0024] In the present invention, a vacuum storage tank is provided between the receiving tank and the vacuum pump. The vacuum degree of the receiving tank is adjusted by this vacuum storage tank to realize the recovery of organic liquid (organic solvent) under the condition of reducing pressure and isolating the vacuum pump environment. The vacuum pump is intermittently turned on instead of continuously working, avoiding the direct continuous evacuation of the system by the vacuum pump, thereby avoiding the organic liquid being evacuated during continuous evacuation, resulting in waste of organic liquid and environmental pollution. By setting an intelligent controller to perform intelligent control of vacuum and safety for the entire system, the present invention greatly improves the accuracy of vacuum degree use, makes the entire process within a stable, safe and controllable range, further improves the recovery rate of organic liquid (solvent), and the process is simple and easy to implement. When the device of the present invention is used for purification and recovery, the recovery rate of organic liquid (solvent) is generally between 98 - 99.5%, with almost no loss. If it is comprehensively promoted, it is expected to avoid tens of millions of tons of organic solvents being emitted into the atmosphere every year, which not only saves resources but also does not cause pollution, and is energy-saving. It is an environmental protection device for reducing waste gas emissions during the recovery of organic solvents. The present invention is applicable to both intermittent feeding and continuous feeding. Generally, intermittent feeding can be adopted for small-scale production, and continuous feeding can be adopted for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the connection structure of the present invention.

[0026] In the figure: 1 - distillation kettle; 1.1 - vacuum pressure gauge; 1.2 - thermometer; 1.3 - stirring motor; 1.4 - motor control switch; 102 - distillation pipe; 2 - receiving tank; 2.1 - receiving tank vacuum gauge; 203 - vacuum regulating pipe; 3 - vacuum storage tank; 3.1 - storage tank vacuum gauge; 304 - vacuum extraction pipe; 4 - vacuum pump; 5 - intelligent controller; 6 - first vacuum regulating valve; 7 - second vacuum regulating valve; 8 - vacuum regulation controller; 9 - safety controller. Specific embodiments

[0027] The following combines with embodiments to more specifically elaborate on the content of the present utility model. The implementation of the present invention is not limited to the following embodiments, and any formal modification or change made to the present invention should be within the protection scope of the present invention.

[0028] The organic solvent purification and recovery device of the present invention, as Figure 1 shown, includes a distillation kettle 1, a receiving tank 2, a vacuum storage tank 3 and a vacuum pump 4. The distillation kettle 1 and the receiving tank 2 are connected by a distillation pipe 102. The distillation pipe 102 extends from the top of the distillation kettle 1 and enters from the top of the receiving tank 2. The receiving tank 2 and the vacuum storage tank 3 are connected by a vacuum regulating pipe 203. The vacuum regulating pipe 203 extends from the top of the receiving tank 2 and enters the vacuum storage tank 3. The vacuum storage tank 3 and the vacuum pump 4 are connected by a vacuum extraction pipe 304. The vacuum extraction pipe 304 is connected from the top of the vacuum storage tank 3 to the vacuum pump 4. A cooling device is provided outside the distillation kettle 1, and a vacuum pressure gauge 1.2 and a thermometer 1.2 are provided inside. The distillation kettle 1 is also provided with a stirring device, and the driving of the stirring device is a stirring motor 1.3, and the stirring motor 1.3 is provided with a motor control switch 1.4. A first vacuum regulating valve 6 is provided on the vacuum regulating pipe 203, and a second vacuum regulating valve 7 is provided on the vacuum extraction pipe 304. A receiving tank vacuum gauge 2.1 and a storage tank vacuum gauge 3.1 are respectively provided on one side of the upper part of the receiving tank 2 and one side of the upper part of the vacuum storage tank 3. The vacuum storage tank 3 is provided with a condensation device, using internal condensation or external condensation, such as an internal circulation coil or a jacket provided outside the vacuum storage tank 3.

[0029] The device further includes an intelligent controller 5. The intelligent controller 5 includes a safety controller 9 and a vacuum regulation controller 8. The safety controller 9 and the vacuum regulation controller 8 can be two functional modules or two separate control components. Intelligent safety control is extremely important in the chemical industry, especially in high-risk chemical reaction processes, and can greatly improve the control accuracy and safety.

[0030] The vacuum pressure gauge 1.2, the thermometer 1.2, the automatic control switch of the cooling device, and the motor control switch 1.4 are all connected to the safety controller 9 through control lines. The first vacuum regulating valve 6, the storage tank pressure gauge 3.1, the second vacuum regulating valve 7, and the vacuum pump 4 are all connected to the vacuum regulating controller 8 through control lines.

[0031] Example 1:

[0032] Input 200 kg of dichloromethane with a mass content of 90% into the distillation kettle 1, and heat it up to 20°C. Close the first vacuum regulating valve 6, open the second vacuum regulating valve 7, turn on the vacuum pump 4 to evacuate the vacuum storage tank 3 to -0.095 MPa, and then close the second vacuum regulating valve 7 and the vacuum pump 4. After the temperature of the distillation kettle 1 stabilizes at 20°C, slowly open the first vacuum regulating valve 6 until the solvent distills out, and collect it in the receiving tank 2. Adjust the opening size of the first vacuum valve 6 according to the flow rate. When the vacuum is insufficient, close the first vacuum regulating valve 6, open the second vacuum regulating valve 7 and the vacuum pump 4 to supplement the vacuum. After the supplementation is completed, close the second vacuum regulating valve 7 and the vacuum pump 4, and open the first vacuum regulating valve 6 to continue the distillation. During the distillation process, to ensure a certain amount of solvent distillate, when the vacuum degree is insufficient in the later stage, in addition to further supplementing the vacuum, the temperature in the distillation kettle 1 will also be appropriately adjusted. In this example, the distillation is continued until 30°C in the later stage and no liquid flows out. 178.2 kg of dichloromethane is recovered. The content of dichloromethane is 99.5%, and the recovery rate is 99%.

[0033] Using existing vacuum distillation equipment, 200 kg of dichloromethane with a mass content of 90% is vacuum distilled at room temperature to obtain 120 kg of dichloromethane, with a recovery rate of 66.7% and a content of 99%.

[0034] Example 2:

[0035] Input 200 kg of ethanol with a mass content of 95% into the distillation kettle 1, and heat it up to 40°C. Close the first vacuum regulating valve 6, open the second vacuum regulating valve 7, turn on the vacuum pump 4 to evacuate the vacuum storage tank 3 to -0.095 MPa, and then close the second vacuum regulating valve 7 and the vacuum pump 4. When the temperature of the distillation kettle 1 stabilizes at 40°C, slowly open the first vacuum regulating valve 6 until the solvent distills out, and collect it in the receiving tank 2. Adjust the opening size of the first vacuum regulating valve 6 according to the flow rate. When the vacuum is insufficient, close the first vacuum regulating valve 6, open the second vacuum regulating valve 7 and the vacuum pump 4 to supplement the vacuum. After the supplementation is completed, close the second regulating valve 7 and the vacuum pump 4, and open the first vacuum regulating valve 6 to continue the distillation. Similar to Example 1, in the later stage, adjust the distillation temperature to 50°C until no liquid flows out. 188.5 kg of ethanol is recovered. The content of ethanol is 99.5%, and the recovery rate is 99.2%.

[0036] 200 kg of ethanol with a mass content of 95% was subjected to vacuum distillation using existing vacuum distillation equipment to obtain 140 kg of ethanol, with a recovery rate of 73.7% and a content of 99%.

[0037] Example 3:

[0038] 200 kg of xylene with a mass content of 95% was input into the distillation kettle 1, and the temperature was raised to 60 °C by heating. The first vacuum regulating valve 6 was closed, the second vacuum regulating valve 7 was opened, and the vacuum pump 4 was started to evacuate the vacuum storage tank 3 to -0.095 MPa, and then the second vacuum regulating valve 7 and the vacuum pump 4 were closed. When the temperature of the distillation kettle 1 was stabilized at 60 °C, the first vacuum regulating valve 6 was slowly opened until the solvent was distilled out, and the opening of the first vacuum regulating valve 6 was adjusted according to the flow rate. When the vacuum was insufficient, the first vacuum regulating valve 6 was closed, the second vacuum regulating valve 7 and the vacuum pump 4 were opened to supplement the vacuum, and after the supplementation was completed, the second regulating valve 6 and the vacuum pump 4 were closed, and the first vacuum regulating valve 6 was opened to continue the distillation. Similar to Example 1, the distillation temperature was adjusted to 80 °C later until no liquid flowed out. 189 kg of xylene was recovered. The content of xylene was 99.5% and the recovery rate was 99.5%.

[0039] 200 kg of xylene with a mass content of 95% was subjected to vacuum distillation using existing vacuum distillation equipment to obtain 170 kg of ethanol, with a recovery rate of 89.5% and a content of 99%.

[0040] Example 4:

[0041] 1000 kg of ethyl acetate with a mass content of 95% was first preheated to 45 °C through a heating kettle or other heating device. The distillation kettle 1 was also preheated to 45 °C. The first vacuum regulating valve 6, the second vacuum regulating valve 7 and the vacuum pump 4 were opened, and the system was evacuated to -0.096 MPa, and then the second vacuum regulating valve 7 and the vacuum pump 4 were closed. Ethyl acetate was continuously input (the input amount was basically the same as the distillate amount of the solvent) into the distillation kettle 1. When the vacuum was insufficient, the first vacuum regulating valve 6 was closed, the second vacuum regulating valve 7 was opened, and the vacuum pump 4 was started to evacuate the vacuum storage tank 3 to -0.096 MPa. After the vacuum supplementation was completed, the second vacuum regulating valve 7 and the vacuum pump 4 were closed, and the first vacuum regulating valve 6 was opened to continue the distillation until no distillate was obtained. 946 kg of ethyl acetate was recovered. The content of ethyl acetate was 99.5% and the recovery rate was 99.5%.

[0042] 200 kg of ethyl acetate with a mass content of 95% was subjected to vacuum distillation using existing vacuum distillation equipment to obtain 130 kg of ethyl acetate, with a recovery rate of 68.4% and a content of 99%.

[0043] Example 5: Solvent Recovery from Gasoline Exhaust

[0044] Open the first vacuum regulating valve 6, the second vacuum regulating valve 7 and the vacuum pump 4, and evacuate the distillation kettle system to -0.096 MPa. Then close the second vacuum regulating valve 7 and the vacuum pump 4. Continuously input 10 m 3 of gasoline waste gas with a gasoline mass content of 0.1% into the distillation kettle 1 slowly, and a small amount of gasoline distills out slowly. When the vacuum is insufficient, close the first vacuum regulating valve 6, open the second vacuum regulating valve 7, and turn on the vacuum pump 4 to evacuate the vacuum storage tank 3 to -0.096 MPa. After the vacuum is replenished, close the second vacuum regulating valve 7 and the vacuum pump 4, open the first vacuum regulating valve 6, and continue distillation until there is no distillate. Recover 7 kg of gasoline waste gas, with a gasoline content of 99% and a recovery rate of 97.2%.

[0045] Gasoline waste gas with a mass concentration of 0.1% cannot recover gasoline in the existing vacuum distillation equipment.

[0046] In the above Examples 1-3, the feeding is intermittent, and in Examples 4-5, the feeding is continuous. During the distillation process of Examples 1-5, the opening and closing of the first vacuum regulating valve 6, the second vacuum regulating valve 7 and the vacuum pump 4 can be controlled manually or by the intelligent controller 5, and the control accuracy of the latter is better than that of the former.

[0047] The latter is controlled as follows:

[0048] The safety controller 9 monitors the vacuum degrees in the distillation kettle 1 and the receiving tank 2 at any time, and transmits signals to the vacuum regulation controller 8. According to the system vacuum degree requirement, the vacuum regulation controller 8 adjusts the opening size of the first vacuum regulating valve 6 to adjust the vacuum degrees in the receiving tank 2 and the distillation kettle 1, so as to form a vacuum distillation suitable for the corresponding solvent. When the vacuum regulation controller 8 monitors that the vacuum degree in the vacuum storage tank 3 is insufficient and needs to replenish the vacuum, the vacuum regulation controller 8 controls the first vacuum regulating valve 6 to close, the second vacuum regulating valve 7 to open, and the vacuum pump 4 to turn on to evacuate the vacuum storage tank 3. When the vacuum regulation controller 8 monitors that the vacuum degree in the vacuum storage tank 3 reaches the set value (-0.95 - 0.98 MPa), the vacuum regulation controller 8 controls the second vacuum regulating valve 7 and the vacuum pump 4 to close, and then opens the first vacuum regulating valve 6 to continue the vacuum distillation.

[0049] The safety controller 9 can monitor the temperature and pressure in the distillation kettle 1 at any time. When the system has over-temperature and over-pressure conditions, the safety controller 9 is activated: when over-temperature occurs, the safety controller 9 issues an alarm, closes the heating valve of the distillation kettle 1, and turns on the cooling water to cool down; when over-pressure occurs, the safety controller 9 also issues an alarm, closes the stirring of the distillation kettle 1, turns on the cooling water to cool down, and turns on the vacuum decompression.

[0050] The device and method of the present invention are particularly applicable to the purification and recovery of organic liquids with boiling points in the range of 20°C - 200°C. It has been experimentally proven that when the temperature is higher than 200°C, such as between 200°C - 300°C, although the improvement in the overall purification and recovery effect is not as obvious as that in the range of 20°C - 200°C, it still has a higher recovery rate compared to the existing purification and recovery devices and methods.

Claims

1. A method for purifying and recycling organic liquids, characterized in that: The device used in this purification and recycling method includes a distillation kettle (1) and a receiving tank (2) connected by a distillation pipe (102). The device also includes a vacuum pump (4). A vacuum storage tank (3) is provided between the receiving tank (2) and the vacuum pump (4). The vacuum storage tank (3) is connected to the receiving tank (2) through a vacuum adjustment pipe (203). A first vacuum adjustment valve (6) is provided on the vacuum adjustment pipe (203). The vacuum storage tank (3) is connected to the vacuum pump (4) through a vacuum extraction pipe (304). A second vacuum adjustment valve (7) is provided on the vacuum extraction pipe (304). This purification and recycling method includes, 1), Input the liquid to be treated into the distillation kettle (1); 2), Disconnect the connection between the vacuum storage tank (3) and the receiving tank (2). Turn on the vacuum pump (4) to evacuate the vacuum storage tank (3) to a predetermined value, then turn off the vacuum pump (4), and disconnect the connection between the vacuum pump (4) and the vacuum storage tank (3); 3), Open the connection between the vacuum storage tank (3) and the receiving tank (2), and the organic liquid distills into the receiving tank (2); 4), When the vacuum in the vacuum storage tank (3) is insufficient, repeat steps 2) and 3) in sequence; 5), Repeat step 4) several times until no more liquid distills.

2. The method for purifying and recycling organic liquids according to claim 1, characterized in that: The device used also includes an intelligent controller (5). The purification and recycling process is controlled by the intelligent controller (5). The intelligent controller (5) includes a vacuum adjustment controller (8) and a safety controller (9). The first vacuum adjustment valve (6), the second vacuum adjustment valve (7), and the pressure monitoring device of the vacuum storage tank (3) are connected to the vacuum adjustment controller (8). The vacuum adjustment controller (8) monitors the pressure in the vacuum storage tank (3) and controls the opening and closing of the first vacuum adjustment valve (6), the second vacuum adjustment valve (7), and the vacuum pump (4); The temperature monitoring device, pressure monitoring device of the distillation kettle (1), pressure monitoring device of the receiving tank (2), and the automatic control valve of the cooling device are connected to the safety controller (9) through a control line. The safety controller (9) monitors the pressure in the receiving tank (2), the pressure and temperature in the distillation kettle (1), and controls the opening and closing of the cooling device and stirring device of the distillation kettle (1).

3. The method for purifying and recycling organic liquids according to claim 2, characterized in that: The cooling water pipe and steam pipe of the cooling device of the distillation kettle (1) are provided with automatic control valves, and the automatic control valves are connected to the intelligent controller (5) through a control line.

4. The method for purifying and recycling organic liquids according to claim 1, characterized in that: The vacuum storage tank (3) is provided with a condensation device.

5. A method for purifying and recycling organic liquids, characterized in that: The device used in this purification and recovery method includes a distillation kettle (1) and a receiving tank (2) connected by a distillation tube (102). The device also includes a vacuum pump (4). A vacuum storage tank (3) is provided between the receiving tank (2) and the vacuum pump (4). The vacuum storage tank (3) is connected to the receiving tank (2) through a vacuum adjustment tube (203). A first vacuum adjustment valve (6) is provided on the vacuum adjustment tube (203). The vacuum storage tank (3) is connected to the vacuum pump (4) through a vacuum extraction tube (304). A second vacuum adjustment valve (7) is provided on the vacuum extraction tube (304). This purification and recovery method includes, 1), Open the connection between the receiving tank (2) and the vacuum storage tank (3) and the connection between the vacuum storage tank (3) and the vacuum pump (4), and turn on the vacuum pump (4) to evacuate the system to a preset value, then turn off the vacuum pump (4) and disconnect the vacuum pump (4) from the vacuum storage tank (3); 2), Continuously input the liquid to be treated into the distillation kettle (1), and the organic liquid distills into the receiving tank (2); 3), When the vacuum in the vacuum storage tank (3) is insufficient, disconnect the connection between the vacuum storage tank (3) and the receiving tank (2), open the connection between the vacuum storage tank (3) and the vacuum pump (4), and turn on the vacuum pump (4) to evacuate the vacuum storage tank (3) to a preset value, then turn off the vacuum pump (4) and disconnect the connection between the vacuum storage tank (3) and the vacuum pump (4), then open the connection between the vacuum storage tank (3) and the receiving tank (2), and continue to distill the liquid; 4), Repeat step 4) several times until no more liquid distills.

6. The organic liquid purification and recovery method according to claim 5, Characterized in that: Before step 1), the distillation kettle (1), and before the liquid to be treated is input into the distillation kettle (1) in step 2), are both preheated to a predetermined value.

7. The organic liquid purification and recovery method according to claim 5, Characterized in that: The device used also includes an intelligent controller (5). The purification and recovery process is controlled by the intelligent controller (5). The intelligent controller (5) includes a vacuum adjustment controller (8) and a safety controller (9). The first vacuum adjustment valve (6), the second vacuum adjustment valve (7), and the pressure monitoring device of the vacuum storage tank (3) are connected to the vacuum adjustment controller (8). The vacuum adjustment controller (8) monitors the pressure in the vacuum storage tank (3) and controls the opening and closing of the first vacuum adjustment valve (6), the second vacuum adjustment valve (7), and the vacuum pump (4); The temperature monitoring device, pressure monitoring device of the distillation kettle (1), the pressure monitoring device of the receiving tank (2), and the automatic control valve of the cooling device are connected to the safety controller (9) through a control line. The safety controller (9) monitors the pressure in the receiving tank (2), the pressure and temperature in the distillation kettle (1), and controls the opening and closing of the cooling device and the stirring device of the distillation kettle (1).

8. The organic liquid purification and recovery method according to claim 7, Characterized in that: The cooling water pipe and steam pipe of the cooling device of the distillation kettle (1) are provided with automatic control valves, and the automatic control valves are connected to the intelligent controller (5) through control lines.

9. The method for purifying and recovering organic liquids according to claim 5, characterized in that: the vacuum storage tank (3) is provided with a condensation device.

Images