Recycling system for ECH rectification light component waste liquid

Abstract

The utility model relates to the technical field of chemical solution recovery, and provides an ECH rectification light component waste liquid recovery system which comprises a recovery tank, a buffer tank and a crude ECH tank, the recovery tank is provided with a gas outlet pipe and a liquid outlet pipe, and the liquid outlet pipe is communicated with the crude ECH tank; the air outlet pipe is connected with a buffer tank, and a condenser is arranged between the recovery tank and the buffer tank; and a steam pipe is arranged in the recovery tank. According to the recovery system for the ECH rectification light component waste liquid, the situation that resources are wasted due to the fact that epoxy chloropropane is directly incinerated is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of chemical solution recovery, and in particular to a recovery system for light component waste liquid of ECH distillation. Background Art

[0002] In the glycerol-based epichlorohydrin process, the light component waste liquid from the distillation section is usually sent directly to the incinerator for incineration. However, the light component waste liquid contains 55% epichlorohydrin (ECH), 7% acrolein, 10% chloroform, 25% vinylidene chloride, and the rest is a small amount of trichloropropane, dichloropropanol and water; the content of epichlorohydrin is relatively high. If the light component waste liquid is directly burned and discharged, it will cause a waste of resources. Utility Model Content

[0003] In order to reduce the waste of resources caused by direct incineration of epichlorohydrin, the present application provides a recovery system for ECH distillation light component waste liquid.

[0004] The present application provides a system for recovering light component waste liquid from ECH distillation, which adopts the following technical solution:

[0005] A recovery system for light component waste liquid of ECH distillation comprises a recovery tank, a buffer tank and a crude ECH tank, wherein the recovery tank is provided with an air outlet pipe and a liquid outlet pipe, wherein the liquid outlet pipe is connected with the crude ECH tank; the air outlet pipe is connected with the buffer tank, a condenser is provided between the recovery tank and the buffer tank; and a steam pipe is provided in the recovery tank.

[0006] By adopting the above technical solution, since the boiling point of epichlorohydrin is higher than the boiling points of other substances in the waste liquid, the waste liquid in the recovery tank is distilled using a steam pipe, which can evaporate other substances below the boiling point of propylene oxide chlorine into steam and enter the buffer tank through the air outlet pipe, and by providing a condenser, the steam can be re-condensed into liquid so that it can be transported to the buffer tank for collection. The unevaporated epichlorohydrin is discharged from the bottom of the tube and transported to the ECH tank for collection and utilization. By providing this equipment, the epichlorohydrin in the waste liquid can be collected centrally, and the direct combustion and discharge of the waste liquid can be reduced, thereby reducing the waste of resources.

[0007] Optionally, the air outlet pipe is arranged at the top of the recovery tank, and a filler layer is arranged on the top wall of the recovery tank.

[0008] By adopting the above technical solution and setting a packing layer, when the waste liquid in the recovery tank is evaporated upward by the steam pipe and discharged from the outlet pipe, the packing layer can absorb the epichlorohydrin in the steam to reduce its overflow through the outlet pipe, thereby further improving the collection efficiency of epichlorohydrin in the waste liquid.

[0009] Optionally, a bracket is provided in the recovery tank, and the filler layer is mounted above the bracket; the recovery tank is provided with an opening for taking out the filler layer, and the recovery tank is provided with a cabinet door, and the cabinet door is used to open and close the opening.

[0010] By adopting the above technical solution, by setting a bracket, the packing layer can be erected on the top, and by setting a cabinet door for opening and closing the opening, the packing layer can be taken out of the recovery tank for cleaning, so as to maintain its absorption effect on epichlorohydrin.

[0011] Optionally, the cabinet door is provided with a sealing strip for abutting against the inner wall of the opening, and a sealing sheet is integrally formed on a side of the sealing strip away from the opening, and the sealing sheet is used to abut against the outer wall of the recovery tank.

[0012] By adopting the above-mentioned technical solution and setting a sealing strip, the sealing effect of the cabinet door closing the collection pipe can be increased, and the situation where the steam in the recovery tank overflows from the gap between the cabinet door and the recovery tank to the outside can be reduced; and the one-piece sealing sheet is abutted against the outer wall of the recovery tank to extend the path between the cabinet door and the recovery tank when the steam in the recovery tank overflows to the outside, thereby further improving the sealing effect.

[0013] Optionally, two groups of filler layers are provided, wherein one group of filler layers is made of activated carbon material, and the other group of filler layers is made of honeycomb ceramic material.

[0014] By adopting the above technical solution, the filler layer made of honeycomb ceramic material can increase the residence time of steam, thereby improving the absorption efficiency; the filler layer made of activated carbon can increase the contact area with steam, and can improve the absorption effect of epichlorohydrin in the steam.

[0015] Optionally, a reflux pipe is provided between the condenser and the recovery tank.

[0016] By adopting the above technical solution, a reflux pipe is set up. After the waste liquid evaporated by the steam pipe enters the condenser, the condenser reintroduces the liquid ECH into the recovery tank for evaporation, so as to improve the utilization rate of ECH.

[0017] Optionally, the reflux pipe is installed on the top of the recovery tank, and a spray head is provided at the end of the reflux pipe and is located inside the recovery tank.

[0018] By adopting the above technical solution, when the condensed ECH enters the recovery tank, the packing layer is wetted by spraying. Then, the liquid can increase the interaction between the gas and the packing, and at the same time prolong the residence time of the gas in the packing layer, further improving the recovery effect of ECH.

[0019] Optionally, the steam pipe is arranged in a disk shape.

[0020] By adopting the above technical solution, the steam pipe is arranged in a disc shape to increase the contact area between the steam pipe and the liquid in the recovery tank, thereby transferring heat more effectively, so that the steam is evenly distributed in the tank, reducing the concentration of heat in a certain area, and improving the overall heat exchange efficiency.

[0021] In summary, the present application includes at least one of the following beneficial technical effects:

[0022] 1. By setting up a recovery tank and using a steam pipe to distill the waste liquid in the recovery tank, other substances with a boiling point lower than that of propylene oxide can be evaporated into steam and enter the buffer tank through the outlet pipe; the unevaporated epichlorohydrin is discharged from the bottom of the pipe and transported to the ECH tank for collection and utilization, which can reduce the direct combustion and discharge of waste liquid, thereby reducing the waste of resources;

[0023] 2. By setting the packing layer, when the waste liquid in the recovery tank is evaporated upward by the steam pipe and discharged from the outlet pipe, the packing layer can absorb the epichlorohydrin in the steam to reduce its overflow through the outlet pipe, further improving the collection efficiency of epichlorohydrin in the waste liquid;

[0024] 3. By setting up a spray head and a reflux pipe, the condensed ECH enters the recovery tank, which can improve the collection effect of epichlorohydrin, and by wetting the packing layer by spraying, the liquid can increase the interaction between the gas and the packing, while prolonging the residence time of the gas in the packing layer, further improving the recovery effect of ECH. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an overall schematic diagram of a system for recovering light component waste liquid from ECH distillation in Example 1;

[0026] Figure 2 is a partial cross-sectional view of the recovery tank of Example 1;

[0027] Figure 3 is a partial cross-sectional view of the recovery tank of Example 2;

[0028] Figure 4 is a schematic structural diagram of a recovery tank in Example 2;

[0029] Figure 5 It is a partial cross-sectional view of the cabinet door of Example 2, mainly showing the sealing strip.

[0030] Explanation of the reference numerals: 1. Recovery tank; 11. Feed inlet; 12. Air outlet pipe; 13. Liquid outlet pipe; 14. Thermal insulation coating; 15. Steam pipe; 16. Opening; 17. Cabinet door; 18. Sealing strip; 19. Sealing sheet; 2. Buffer tank; 21. Condenser; 22. First centrifugal pump; 23. Reflux pipe; 24. Sprinkler head; 3. Crude ECH tank; 31. Cooler; 32. Second centrifugal pump; 4. Waste liquid tank; 5. Packing layer; 51. Bracket. DETAILED DESCRIPTION

[0031] The following is combined with Figure 1-5 This application is described in further detail.

[0032] Embodiment 1:

[0033] The embodiment of the present application discloses a system for recovering light component waste liquid from ECH distillation.

[0034] Reference Figure 1 , a recovery system for light component waste liquid of ECH distillation, comprising a recovery tank 1, a buffer tank 2, a crude ECH tank 3 and a waste liquid tank 4, and referring to Figure 2 The top and bottom of the recovery tank 1 are respectively provided with an air outlet pipe 12, a liquid outlet pipe 13 and a feed port 11. The feed port 11 is used to discharge the waste liquid into the recovery tank 1 for treatment, the air outlet pipe 12 is used to discharge the steam in the recovery tank 1, and the liquid outlet pipe 13 is used to discharge the solution in the recovery tank 1.

[0035] Reference Figure 2 The recovery tank 1 is made of corrosion-resistant materials to reduce the corrosion caused by long-term waste liquid treatment and increase the service life of the recovery tank 1; the outer wall of the recovery tank 1 is provided with a thermal insulation coating 14, and the thermal insulation coating 14 uses thermal insulation materials to improve the thermal insulation effect of the recovery tank 1 and reduce the temperature inside the recovery tank 1 from being dissipated to the outside.

[0036] A steam pipe 15 is provided at the bottom of the recovery tank 1, and the steam pipe 15 is arranged in a disc shape; the steam pipe 15 can heat the waste liquid in the recovery tank 1. In this embodiment, the heating temperature of the recovery tank 1 by the steam pipe 15 is 105-110°C; under normal pressure, the boiling point of vinylidene chloride is 31°C, the boiling point of acrolein is 52.5°C, the boiling point of chloroform is 61°C, and the boiling point of epichlorohydrin is 115°C; therefore, when the waste liquid in the recovery tank 1 is heated, the light component impurities of the waste gas can evaporate and be discharged through the outlet pipe 12, and the epichlorohydrin liquid remains in the recovery tank 1 and is discharged from the liquid outlet pipe 13.

[0037] By arranging the steam pipe 15 in a disk shape, the contact area between the steam pipe 15 and the liquid in the recovery tank 1 can be increased, thereby transferring heat more effectively, so that the steam is evenly distributed in the tank, reducing the concentration of heat in a certain area, and improving the overall heat exchange efficiency.

[0038] A packing layer 5 is provided on the top wall of the recovery tank 1. The packing layer 5 can be made of materials such as ceramics or plastics. In the present embodiment, the packing layer 5 is made of ceramic materials. When the waste liquid in the recovery tank 1 is discharged through the outlet pipe 12 by the steam pipe 15, the packing layer can absorb the epichlorohydrin in the steam to reduce the overflow of the epichlorohydrin through the outlet pipe 12, thereby further improving the collection efficiency of the epichlorohydrin in the waste liquid.

[0039] Reference Figure 1 A condenser 21 is provided at one end of the outlet pipe 12 away from the recovery tank 1. The condenser 21 is used to condense the light component impurities evaporated from the outlet pipe 12 into liquid and discharge it into the buffer tank 2; in this embodiment, a reflux pipe 23 is provided between the condenser 21 and the recovery tank 1, and the reflux pipe 23 is installed on the top of the recovery tank 1 and is provided with a spray head 24, and the spray head 24 is located inside the recovery tank 1.

[0040] The reflux pipe 23 can reflux the epichlorohydrin condensed in the condenser 21 back into the recovery tank 1, further improving the collection effect of epichlorohydrin in the waste liquid; and in the process of the epichlorohydrin condensed into liquid entering the recovery tank 1, the packing layer 5 is wetted by spraying, so that the liquid can increase the interaction between the gas and the packing, and at the same time prolong the residence time of the gas in the packing layer 5, further improving the recovery effect of ECH.

[0041] In this embodiment, a first centrifugal pump 22 is provided between the buffer tank 2 and the waste liquid tank 4. The first centrifugal pump 22 can extract the condensed waste liquid from the buffer tank 2 and stably transport it to the waste liquid tank 4, and then incinerate it.

[0042] The liquid outlet pipe 13 of the waste liquid tank 4 is provided with a cooler 31, and the cooler 31 is used to cool the epichlorohydrin liquid at the bottom of the recovery tank 1; a second centrifugal pump 32 is provided between the cooler 31 and the crude ECH tank 3, and the second centrifugal pump 32 is used to stably discharge the cooled ECH into the crude ECH tank 3 for its utilization.

[0043] The implementation principle of Example 1 of the present application is:

[0044] Since the boiling point of epichlorohydrin is higher than that of other substances in the waste liquid, the waste liquid in the recovery tank 1 is distilled using the steam pipe 15, so that other substances with a boiling point lower than that of propylene oxide chlorine can be evaporated into steam and enter the buffer tank 2 through the outlet pipe 12, and by providing a condenser 21, the steam can be recondensed into liquid so that it can be transported to the buffer tank 2 for collection. The unevaporated epichlorohydrin is discharged from the bottom of the tube and transported to the ECH tank for collection and utilization. By providing this equipment, the epichlorohydrin in the waste liquid can be collected centrally, and the direct combustion and discharge of the waste liquid can be reduced, thereby reducing the waste of resources.

[0045] Embodiment 2:

[0046] The embodiment of the present application discloses a system for recovering light component waste liquid from ECH distillation.

[0047] Reference Figure 3 The difference between Example 2 of the present application and Example 1 is that: two brackets 51 are arranged in the recovery tank 1, and the two brackets 51 are arranged at intervals along the height direction of the recovery tank 1; two groups of packing layers 5 are arranged, and the two groups of packing layers 5 are respectively mounted on the two brackets 51.

[0048] In this embodiment, the two groups of packing layers 5 are made of different materials, one group of packing layers 5 is made of activated carbon particles, and the other group of packing layers 5 is made of honeycomb ceramic material; the packing layer 5 made of ceramic material is located above the packing layer 5 made of activated carbon material.

[0049] The two groups of packing layers 5 are set to different structures. The activated carbon granular packing layer 5 is mainly responsible for the initial efficient absorption, while the packing layer 5 made of honeycomb ceramics further ensures the uniform distribution and deep absorption of the gas, thereby improving the absorption effect of the packing layer 5 on epichlorohydrin in the steam, thereby reducing the waste of resources.

[0050] Reference Figure 4 The recovery tank 1 is provided with an opening 16 for taking the packing layer 5 out of the outside, and the recovery tank 1 is provided with a cabinet door 17, which is used to open and close the opening 16. The packing layer 5 can be taken out and cleaned through the cabinet door 17 to maintain the absorption effect of epichlorohydrin. Figure 5 A sealing strip 18 is provided between the cabinet door 17 and the inner wall of the opening 16, and a sealing sheet 19 is integrally formed on the side of the sealing strip 18 away from the recovery tank 1, and the sealing sheet 19 is used to abut against the inner wall of the recovery tank 1. The provision of the sealing strip 18 and the sealing sheet 19 can increase the sealing effect between the cabinet door 17 and the recovery tank 1, and reduce the situation where the steam in the recovery tank 1 overflows from the gap between the cabinet door 17 and the recovery tank 1 to the outside.

[0051] The above are preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A system for recovering light component waste liquid from ECH distillation, characterized by: The invention comprises a recovery tank (1), a buffer tank (2) and a crude ECH tank (3); the recovery tank (1) is provided with an air outlet pipe (12) and a liquid outlet pipe (13); the liquid outlet pipe (13) is connected to the crude ECH tank (3); the air outlet pipe (12) is connected to the buffer tank (2); a condenser (21) is provided between the recovery tank (1) and the buffer tank (2); and a steam pipe (15) is provided inside the recovery tank (1).

2. The system for recovering light component waste liquid from ECH distillation according to claim 1, characterized in that: The air outlet pipe (12) is arranged at the top of the recovery tank (1), and a filler layer (5) is arranged on the inner top wall of the recovery tank (1).

3. The ECH distillation light component waste liquid recovery system according to claim 2, characterized in that: The recovery tank (1) is provided with a support (51), and the packing layer (5) is mounted above the support (51); the recovery tank (1) is provided with an opening (16) for taking out the packing layer (5), and the recovery tank (1) is provided with a cabinet door (17), and the cabinet door (17) is used to open and close the opening (16).

4. The system for recovering light component waste liquid from ECH distillation according to claim 3, characterized in that: The cabinet door (17) is provided with a sealing strip (18) for abutting against the inner wall of the opening (16); a sealing sheet (19) is integrally formed on a side of the sealing strip (18) away from the opening (16); and the sealing sheet (19) is used to abut against the outer wall of the recovery tank (1).

5. The system for recovering light component waste liquid from ECH distillation according to claim 2, characterized in that: The packing layers (5) are provided in two groups, wherein one group of packing layers (5) is made of activated carbon material, and the other group of packing layers (5) is made of honeycomb ceramic material.

6. The system for recovering light component waste liquid from ECH distillation according to claim 2, characterized in that: A reflux pipe (23) is provided between the condenser (21) and the recovery tank (1).

7. The system for recovering light component waste liquid from ECH distillation according to claim 6, characterized in that: The return pipe (23) is installed on the top of the recovery tank (1); a spray head (24) is provided at the end of the return pipe (23) and is located inside the recovery tank (1).

8. The system for recovering light component waste liquid from ECH distillation according to claim 1, characterized in that: The steam pipe (15) is arranged in a disk-like manner.

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