A tetrachloroethylene recovery device for ketoxime production waste gas

Abstract

This utility model relates to the field of chemical production waste gas treatment technology, and discloses a tetrachloroethylene recovery device for ketoxime production waste gas. It includes an original condenser ring refrigerant system, with a cryogenic unit connected to the exhaust end of the original condenser ring refrigerant system. An exhaust pipe is connected to the exhaust end of the cryogenic unit, and an adsorption tower is connected to the other end of the exhaust pipe. An inlet pipe is connected to one side of the adsorption tower, and a cleaning water pump is connected to the other end of the inlet pipe. This utility model enhances condensation and improves the tetrachloroethylene recovery rate by adding a cryogenic unit to the original condensation system. It uses hydrophobic adsorption resin as filler to selectively adsorb residual tetrachloroethylene. An online tetrachloroethylene concentration monitor automatically adjusts the backwashing frequency based on concentration changes. Tetrachloroethylene backwash liquid is used to recover the adsorbed solvent, and alkaline solution is used for rinsing to ensure the waste gas purification effect. Simultaneously, the backwash liquid undergoes distillation and dehydration treatment to improve the recovery purity.

Description

Technical Field

[0001] This utility model relates to the field of chemical production waste gas treatment technology, specifically a tetrachloroethylene recovery device for ketoxime production waste gas. Background Technology

[0002] In the production of ketoxime extractants, tetrachloroethylene is used as the reaction solvent. The main function of tetrachloroethylene is to promote the dissolution of reactants and improve mass transfer efficiency. When nonylphenol ester and aluminum trichloride undergo a rearrangement reaction, the reaction is carried out at a temperature close to the boiling point of tetrachloroethylene, 121.7°C. The hydrogen chloride gas generated in the reaction will cause the solvent tetrachloroethylene to volatilize. Hydrogen chloride is a corrosive gas that is easily soluble in water and requires purification treatment. The tetrachloroethylene it carries is a volatile toxic compound with carcinogenic properties and needs to be treated and recovered.

[0003] The original waste gas treatment process was as follows: (1) After the waste gas passed through the condenser, hydrogen chloride, tetrachloroethylene gas and water formed a hydrochloric acid solution containing tetrachloroethylene. After static separation, the tetrachloroethylene aqueous solution after separation of the aqueous phase was reused through a tetrachloroethylene distillation and dehydration device; (2) After the light components of the waste gas passing through the condenser entered the U-tube and receiving tank, the purified tail gas was discharged. However, this method is not thorough in purifying tetrachloroethylene. When the rearrangement reaction proceeds rapidly, the amount of waste gas generated is large. The waste gas passes through the condenser for a short time, which easily leads to the presence of a small amount of tetrachloroethylene in the discharged gas, which may pollute the environment. The tetrachloroethylene recovery rate is reduced, which increases the production cost. Utility Model Content

[0004] The purpose of this invention is to provide a tetrachloroethylene recovery device for ketoxime production waste gas, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: It includes a primary condenser ring refrigerant, with a cryogenic unit connected to its exhaust end. An exhaust pipe is connected to the exhaust end of the cryogenic unit, and an adsorption tower is connected to the other end of the exhaust pipe. An inlet pipe is connected to one side of the adsorption tower, and a cleaning water pump is connected to the other end of the inlet pipe. A backflushing liquid tank is connected to the inlet of the cleaning water pump. An online tetrachloroethylene concentration monitor is connected to one side of the top of the adsorption tower. A transfer pipe is connected to the top of the adsorption tower, and a spray tower is connected to the other end of the transfer pipe. A second inlet pipe is connected to one side of the spray tower, and a spray water pump is connected to the other end of the second inlet pipe. An alkali tank is connected to the inlet of the spray water pump. The online tetrachloroethylene concentration monitor and the cleaning water pump are electrically connected.

[0006] Preferably, both the adsorption tower and the spray tower are connected to a recovery pipe at their bottom ends, and a drain pump is connected to the other end of each recovery pipe. A riser pipe is connected to the drain end of each drain pump, and a backflushing liquid collection tank and an alkali liquid collection tank are respectively connected to the other end of each riser pipe.

[0007] Preferably, each of the two recovery pipes is equipped with an automatic drain valve at one end near the adsorption tower and the spray tower.

[0008] Preferably, a liquid inlet pump is connected to one side of the backflushing liquid collection tank, a long pipe is connected to the drain end of the liquid inlet pump, and an evaporation reactor is connected to the other end of the long pipe.

[0009] Preferably, a valve is connected to one end of the exhaust pipe near the adsorption tower. The adsorption tower is made of stainless steel, with a PTFE lining on the inner wall and filled with a high specific surface area hydrophobic resin.

[0010] Preferably, one end of both the second inlet pipe and the first inlet pipe extends into the corresponding spray tower and adsorption tower, and is connected to a spray head.

[0011] Preferably, a gas pipe is connected between the original condenser ring and the cryogenic unit, and a condensate collection tank is connected to one side of the same pipe. A return pipe is connected to one side of the condensate collection tank, and the other end of the return pipe is connected to a recovery pipe located on the side of the backflushing liquid collection tank.

[0012] In summary, this application includes the following beneficial technical effects:

[0013] By adding a cryogenic unit to the original condensation system, condensation is enhanced and the tetrachloroethylene recovery rate is improved. Hydrophobic adsorption resin is used as a filler to selectively adsorb residual tetrachloroethylene. An online tetrachloroethylene concentration monitor is used to automatically adjust the backwashing frequency according to the concentration change. A two-stage backwashing process is adopted. The first stage uses tetrachloroethylene backwashing liquid to recover the adsorbed solvent, and the second stage uses alkaline solution to rinse, ensuring the purification effect of the exhaust gas. At the same time, the backwashing liquid is distilled and dehydrated to improve the purity of the recovered gas. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of a tetrachloroethylene recovery device for ketoxime production waste gas according to the present invention;

[0015] Figure 2 This is a schematic diagram of the test structure of a tetrachloroethylene recovery device for ketoxime production waste gas according to this utility model;

[0016] Figure 3 This is a schematic diagram of the working process of a tetrachloroethylene recovery device for ketoxime production waste gas according to this utility model.

[0017] In the diagram: 1. Original condenser ring; 2. Cryogenic unit; 3. Exhaust pipe one; 31. Valve; 4. Adsorption tower; 5. Inlet pipe one; 6. Cleaning water pump; 7. Backflushing liquid tank; 8. Tetrachloroethylene concentration online monitor; 9. Transfer pipe; 10. Spray tower; 11. Inlet pipe two; 12. Alkali tank; 13. Recovery pipe; 14. Drain pump; 15. Riser pipe; 16. Backflushing liquid collection tank; 17. Alkali collection tank; 18. Liquid inlet pump; 19. Long pipe; 20. Evaporation reactor; 21. Condensate collection tank; 111. Spray water pump; 222. Gas pipe. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Please see Figure 1-3 This utility model provides a technical solution: it includes an original condenser ring 1, a cryogenic unit 2 connected to the exhaust end of the original condenser ring 1, an exhaust pipe 3 connected to the exhaust end of the cryogenic unit 2, an adsorption tower 4 connected to the other end of the exhaust pipe 3, an inlet pipe 5 connected to one side of the adsorption tower 4, a cleaning water pump 6 connected to the other end of the inlet pipe 5, a backflushing liquid tank 7 connected to the inlet end of the cleaning water pump 6, an online tetrachloroethylene concentration monitor 8 connected to one side of the top of the adsorption tower 4, a transfer pipe 9 connected to the top of the adsorption tower 4, and a spray tower 10 connected to the other end of the transfer pipe 9. As can be seen from the attached drawings, a solenoid valve is connected to one end of the transfer pipe 9, an inlet pipe 11 is connected to one side of the spray tower 10, a spray water pump 111 is connected to the other end of the inlet pipe 11, an alkali tank 12 is connected to the inlet end of the spray water pump 111, and the online tetrachloroethylene concentration monitor 8 and the cleaning water pump 6 are electrically connected.

[0020] Reference Figure 1 As shown, both the adsorption tower 4 and the spray tower 10 are connected to a recovery pipe 13 at their bottom ends, and a drain pump 14 is connected to the other end of each recovery pipe 13. An automatic drain valve is connected to the end of each recovery pipe 13 near the adsorption tower 4 and the spray tower 10. A riser pipe 15 is connected to the drain end of each drain pump 14. A backflushing liquid collection tank 16 and an alkali collection tank 17 are connected to the other end of each riser pipe 15. The drain pump 14 extracts the liquid used for backflushing in the adsorption tower 4 and spraying in the spray tower 10 through the recovery pipe 13. When extracting, the automatic drain valve opens automatically and discharges the liquid through the riser pipe 15 into the corresponding backflushing liquid collection tank 16 and alkali collection tank 17 to collect the backflushing liquid and spraying alkali.

[0021] A liquid inlet pump 18 is connected to one side of the backflushing liquid collection tank 16. A long pipe 19 is connected to the drain end of the liquid inlet pump 18. The other end of the long pipe 19 is connected to the evaporation reactor 20. The liquid inlet pump 18 discharges the backflushing liquid collected in the backflushing liquid collection tank 16 that has adsorbed tetrachloroethylene to the evaporation reactor 20 through the long pipe 19 for evaporation and purification, thereby recovering tetrachloroethylene.

[0022] Reference Figure 2 As shown, a valve 31 is connected to one end of the exhaust pipe 3 near the adsorption tower 4. The adsorption tower 4 is made of 316L stainless steel and has a PTFE lining on the inner wall, which is corrosion-resistant and impermeable. It is also filled with a high specific surface area hydrophobic resin to selectively adsorb residual tetrachloroethylene in the exhaust gas.

[0023] One end of each of the two inlet pipes 11 and 5 extends into the corresponding spray tower 10 and adsorption tower 4, and is connected to a spray head (not shown). Since this is a standard setup, it is not described in detail in the instruction manual.

[0024] Reference Figure 2 and Figure 1 As shown, a gas pipe 222 is installed between the original condenser ring 1 and the cryogenic unit 2, and a condensate collection tank 21 is installed on one side of the same pipe. A return pipe is installed on one side of the condensate collection tank 21, and the other end of the return pipe is connected to the recovery pipe 13 located on the side of the backflushing liquid collection tank 16. The exhaust gas enters the original condenser ring 1 and then enters the cryogenic unit 2 for further cooling to improve condensation efficiency. The condensate produced by the original condenser ring 1 and the cryogenic unit 2 can be collected in the condensate collection tank 21. The drain pump 14 located on the side of the backflushing liquid collection tank 16 is started, and the condensate in the drain pump 14 can be drawn through the return pipe and discharged into the backflushing liquid collection tank 16 for recycling.

[0025] The implementation principle of this application is as follows: In use, the waste gas is discharged into the original condenser ring 1 and then condensed by the cryogenic unit 2 to lower the waste gas temperature. It then enters the adsorption tower 4 through exhaust pipe 3 to adsorb tetrachloroethylene in the waste gas. The adsorbed gas is discharged into the spray tower 10 through the transfer pipe 9. While discharging into the spray tower 10, the tetrachloroethylene concentration online monitoring instrument 8 monitors the adsorbed waste gas in real time. When the concentration is ≥30ppm, the solenoid valve at one end of the transfer pipe 9 is closed, the cleaning water pump 6 is started, and the backflushing liquid in the backflushing tank 7 is drawn and discharged through the inlet pipe 5 to… The adsorption tower 4 is flushed, and when the concentration is ≤30ppm, it is smoothly discharged into the spray tower 10. The spray water pump 111 draws out the alkali solution in the alkali solution tank 12 to spray and purify the waste gas, and then discharges it. The backflushing liquid in the adsorption tower 4 and the spray liquid in the spray tower 10 can be drawn out by the corresponding discharge pump 14 and discharged into the corresponding backflushing liquid collection tank 16 and alkali solution collection tank 17 for collection. The backflushing liquid collected in the backflushing liquid collection tank 16 is drawn out by the liquid pump 18 and discharged into the evaporation reactor 20 through the long pipe 19 for evaporation, thereby concentrating the backflushing liquid to achieve high-purity tetrachloroethylene.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0027] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for recovering tetrachloroethylene waste gas from ketoxime production, comprising the original condenser ring (1), characterized in that: The original condenser (1) is connected to a cryogenic unit (2) at its exhaust end. The cryogenic unit (2) is connected to an exhaust pipe (3) at its exhaust end. An adsorption tower (4) is connected to the other end of the exhaust pipe (3). An inlet pipe (5) is connected to one side of the adsorption tower (4). A cleaning water pump (6) is connected to the other end of the inlet pipe (5). A backflushing tank (7) is connected to the inlet end of the cleaning water pump (6). A tetrachloroethylene tank is connected to one side of the top of the adsorption tower (4). The tetrachloroethylene concentration online monitoring instrument (8) is provided with a transfer pipe (9) connected to the top of the adsorption tower (4), and a spray tower (10) connected to the other end of the transfer pipe (9). A liquid inlet pipe (11) is connected to one side of the spray tower (10), and a spray water pump (111) is connected to the other end of the liquid inlet pipe (111). An alkali tank (12) is connected to the water inlet of the spray water pump (111). The tetrachloroethylene concentration online monitoring instrument (8) is electrically connected to the cleaning water pump (6).

2. The tetrachloroethylene recovery device for ketoxime production waste gas according to claim 1, characterized in that: The bottom ends of the adsorption tower (4) and the spray tower (10) are both connected to a recovery pipe (13), and the other end of the recovery pipe (13) is connected to a drain pump (14). The drain end of the drain pump (14) is connected to a riser pipe (15), and the other end of the riser pipe (15) is connected to a backflushing liquid collection tank (16) and an alkali liquid collection tank (17).

3. The tetrachloroethylene recovery device for ketoxime production waste gas according to claim 2, characterized in that: Automatic drain valves are connected to one end of each of the two recovery pipes (13) near the adsorption tower (4) and the spray tower (10).

4. The tetrachloroethylene recovery device for ketoxime production waste gas according to claim 3, characterized in that: A liquid pump (18) is connected to one side of the backflushing liquid collection tank (16), and a long pipe (19) is connected to the drain end of the liquid pump (18). An evaporation reactor (20) is connected to the other end of the long pipe (19).

5. The tetrachloroethylene recovery device for ketoxime production waste gas according to claim 4, characterized in that: The exhaust pipe (3) is connected to a valve (31) at one end near the adsorption tower (4). The adsorption tower (4) is made of (316)L stainless steel, with a PTFE lining on the inner wall and filled with a high specific surface area hydrophobic resin.

6. The tetrachloroethylene recovery device for ketoxime production waste gas according to claim 5, characterized in that: One end of each of the two inlet pipes (11) and one inlet pipe (5) extends into the corresponding spray tower (10) and adsorption tower (4), and is connected to a spray head.

7. The tetrachloroethylene recovery device for ketoxime production waste gas according to claim 6, characterized in that: A gas pipe (222) is connected between the original condenser ring (1) and the cryogenic unit (2), and a condensate collection tank (21) is connected to one side of the same tank. A return pipe is connected to one side of the condensate collection tank (21), and the other end of the return pipe is connected to a recovery pipe (13) located on one side of the backflushing liquid collection tank (16).

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