A trifluorotrichloroethane deacidification device

Abstract

The invention belongs to the technical field of chemical equipment, and discloses a trifluorotrichloroethane deacidification device, including a circulation tower, an acidic material receiving tank, a cryogenic condenser, a stratification tank, a material cooler, a deacidification tower kettle, a deacidification tower, a deacidification tower condenser, a deacidification tower feed pump, a material water washing tower, a material alkali washing tower, a water cooler, an alkali washing circulation pump, an alkali washing circulation tank, and a water separator; the cryogenic condenser is connected to the circulation tower, the circulation tower, the stratification tank and the acidic material receiving tank are connected through a gas phase balance pipe, the circulation tower and the stratification tank are connected, and the lower part of the stratification tank is connected to the acidic material receiving tank; the deacidification tower kettle is connected to the acidic material receiving tank, the lower part of the material water washing tower is connected to the upper part of the material alkali washing tower, the lower part of the material alkali washing tower is connected to the upper part of the water separator, and the upper part of the material alkali washing tower is connected to the alkali washing circulation tank. The present invention is applied to the trifluorotrichloroethane deacidification system, the water washing and alkali washing systems are easy to operate, the acidic material content of the product trifluorotrichloroethane is reduced, and the product quality is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical equipment, and in particular relates to a trifluorotrichloroethane deacidification device. Background Art

[0002] The production equipment of trifluorotrichloroethane generally uses tetrachloroethylene, hydrogen fluoride and liquid chlorine to carry out fluorination and chlorination reactions in the reactor. The materials at the outlet of the reaction reflux tower condenser contain trifluorotrichloroethane, hydrogen chloride, hydrogen fluoride and other gases. In order to condense and recover most of the trifluorotrichloroethane and hydrogen fluoride in the gas, the gas at the outlet of the reaction reflux tower condenser adopts a four-stage condenser of pre-cooling, inter-cooling, tail cooling and deep cooling to condense. Most of the hydrogen fluoride, trifluorotrichloroethane and a small amount of hydrogen chloride in the gas will be condensed to form acidic materials. During the stratification process of the acidic material in the stratification tank, the crude trifluorotrichloroethane is deposited in the lower part of the stratification tank, and some hydrogen chloride and trace hydrogen fluoride will be entrained into the acidic material receiving tank. Generally, enterprises use water washing and alkali washing to treat the deacidification device, which consumes a large amount of tap water, the concentration of hydrochloric acid is difficult to control, and the deacidification effect is not good. Summary of the invention

[0003] In order to solve the technical problems existing in the prior art, the present invention provides a trifluorotrichloroethane deacidification device, comprising a circulation tower, an acidic material receiving tank, a deep cooling condenser, a stratification tank, a material cooler, a deacidification tower kettle, a deacidification tower, a deacidification tower condenser, a deacidification tower feed pump, a material water washing tower, a material alkali washing tower, a water cooler, an alkali washing circulation pump, an alkali washing circulation tank, and a water separator.

[0004] After the outlet gas of the condenser of the trifluorotrichloroethane reaction reflux tower is condensed by the pre-cooling, inter-cooling and tail-cooling condensers, the uncondensed gas enters the deep-cold condenser for further condensation; the deep-cold condenser uses Freon cooling. Due to the different boiling points, hydrogen fluoride is 19.5℃, trifluorotrichloroethane is 47℃, and hydrogen chloride is -85℃, most of the hydrogen fluoride, trifluorotrichloroethane and part of the hydrogen chloride in the gas are condensed, and the uncondensed hydrogen chloride gas and trace hydrogen fluoride and trifluorotrichloroethane enter the gas phase water washing and alkali washing system for treatment. The deep-cold condenser is connected to the circulation tower, and the condensate of the deep-cold condenser overflows to the feeding pipe in the middle of the circulation tower.

[0005] The condensate from each condenser enters the circulation tower. The tower body of the circulation tower is insulated with rock wool, and the tower kettle is insulated with frozen brine to control the pressure of the circulation tower to prevent the hydrogen fluoride and trichlorotrifluoroethane from escaping in large quantities. The tower body of the circulation tower is equipped with packing. During the rising process of the tower body packing layer, part of the gas escaping from the tower kettle liquid is condensed by the condensate flowing down from the top of the tower, and the uncondensed gas enters the deep cold condenser for further condensation. The circulation tower and the stratification tank use pipelines to balance the pressure, and the liquid at the bottom of the circulation tower enters the stratification tank through the overflow pipe.

[0006] The circulation tower, the stratification tank and the acidic material receiving tank are connected through a gas phase balance pipe, the circulation tower and the stratification tank are connected, the stratification tank and the acidic material receiving tank are connected, and the upper part of the stratification tank is connected with a dehydrogen fluoride recovery tank; the circulation tower, the stratification tank and the acidic material receiving tank use a balance pipeline to balance the pressure and control the pressure to be consistent; the condensate of the circulation tower overflows to the stratification tank, the condensate is stratified in the stratification tank, hydrogen fluoride accumulates in the upper part of the stratification tank, trifluorotrichloroethane accumulates in the lower part of the stratification tank, the upper hydrogen fluoride overflows to the hydrogen fluoride recovery tank, and the lower trifluorotrichloroethane containing hydrogen chloride and a trace of hydrogen fluoride overflows to the acidic material receiving tank; the acidic material in the acidic material receiving tank is pressed into the middle feeding pipe of the deacidification tower under the action of pressure after the liquid level is controlled by a liquid level regulating valve.

[0007] The liquid overflow at the bottom of the circulation tower enters the stratification tank. Using the principle that hydrogen fluoride, hydrogen chloride and crude trifluorotrichloroethane are immiscible and have different densities, the relative density of hydrogen fluoride (water) is 1.15, the relative density of hydrogen chloride (water) is 1.19, and the relative density of trifluorotrichloroethane (water) is 1.579. Hydrogen fluoride, hydrogen chloride and trifluorotrichloroethane are stratified in the stratification tank, hydrogen fluoride accumulates in the upper part, trifluorotrichloroethane accumulates in the lower part, and a trace amount of hydrogen chloride accumulates in the middle; the stratification tank and the acid material receiving tank use pipelines to balance the pressure, and the stratification tank is controlled to prevent gasification. At the same time, the crude trifluorotrichloroethane at the bottom of the stratification tank enters the acid material receiving tank through the overflow pipe.

[0008] The liquid at the bottom of the stratification tank enters the acidic material receiving tank through the overflow pipe, and the gas in the acidic material receiving tank enters the stratification tank. The acidic material receiving tank and the stratification tank use pipelines to balance the pressure, control the pressure of the acidic material receiving tank to prevent gasification, and at the same time, a liquid level regulating valve is installed on the discharge pipeline of the acidic material receiving tank. The acidic material in the acidic material receiving tank is controlled to a certain liquid level under the action of pressure, and the acidic material in the acidic material receiving tank enters the deacidification tower through the liquid level regulating valve.

[0009] A deacidification tower is arranged on the upper part of the deacidification tower kettle, and a deacidification tower condenser is arranged on the upper part of the deacidification tower. The deacidification tower kettle is connected with the acidic material receiving tank. The deacidification tower kettle is heated by steam. After the acidic material is heated in the deacidification tower kettle, hydrogen chloride, hydrogen fluoride and part of trifluorotrichloroethane are gasified and rise to the deacidification tower, and most of trifluorotrichloroethane is cooled by the cold acidic material in the middle of the deacidification tower. Hydrogen chloride, hydrogen fluoride and trace trifluorotrichloroethane gas rise to the deacidification tower condenser, and trifluorotrichloroethane is condensed. Most of hydrogen chloride and hydrogen fluoride enter the gas phase water washing system for absorption through the outlet pipeline of the deacidification tower condenser.

[0010] The acidic material in the acidic material receiving tank enters the feed port in the middle of the deacidification tower through the liquid level regulating valve. The acidic material mainly contains trichlorotrifluoroethane, hydrogen chloride and a trace amount of hydrogen fluoride. The acidic material contacts the hot air flow rising from the bottom of the deacidification tower in countercurrent through the packing layer. The cold acidic material is heated, and a large amount of hydrogen chloride and a trace amount of hydrogen fluoride in the acidic material are gasified and rise. The hot air flow contains trichlorotrifluoroethane, hydrogen chloride and hydrogen fluoride. Most of the trichlorotrifluoroethane in the hot air flow is cooled down by the cold acidic material and returns to the deacidification tower kettle along with the acidic material at the feed port. The uncondensed hydrogen chloride, hydrogen fluoride gas and a trace amount of trichlorotrifluoroethane gas in the hot air flow rise to the condenser of the deacidification tower.

[0011] A deacidification tower feed pump and a material cooler are provided between the deacidification tower kettle and the material water washing tower. The water washing liquid at the upper part of the material water washing tower overflows to the gas phase water washing system. The lower part of the material water washing tower is connected to the material alkali washing tower. The material alkali washing tower and the alkali washing circulation tank are connected through an alkali washing circulation pump. A water supply pipeline is provided at the lower part of the material water washing tower. The water supply pipeline is provided with a water cooler. The water cooler is cooled by refrigerated brine to prevent the temperature of the material water washing tower from being too high. The lower part of the material alkali washing tower is connected to the upper part of the water distributor. A water supply pipeline is provided at the upper part of the water distributor. The lower part of the water distributor is connected to the coarse material intermediate tank. The upper part of the water distributor is connected to the waste water tank.

[0012] The deacidification tower kettle is heated by passing steam through the jacket, and a steam regulating valve is installed on the steam inlet pipeline to control the temperature of the deacidification tower kettle. After the acidic material at the bottom of the kettle is heated, the hydrogen chloride, hydrogen fluoride and part of trifluorotrichloroethane in the acidic material are vaporized, and the hot air flow rises to the deacidification tower. The acidic material at the feed port in the middle of the deacidification tower is buffered by the packing layer and the condensate after cooling part of the hot air flow enters the deacidification tower kettle together, reducing the content of hydrogen chloride and hydrogen fluoride in the acidic material. A liquid level regulating valve is installed on the discharge pipeline of the deacidification tower kettle to control a certain liquid level. The crude product of the deacidification tower kettle enters the inlet pipeline of the deacidification tower feed pump through the liquid level regulating valve.

[0013] The uncondensed hydrogen chloride and trace amounts of hydrogen fluoride and trichlorotrifluoroethane gas at the feed inlet of the deacidification tower rise to the deacidification tower condenser; a cooling water flow regulating valve is installed on the deacidification tower condenser to control the top temperature of the deacidification tower condenser by adjusting the flow of cooling water in the deacidification tower condenser; most of the trichlorotrifluoroethane and trace amounts of hydrogen fluoride in the hot gas flow condense and return to the deacidification tower kettle, and the uncondensed hydrogen chloride enters the gas phase water washing system, reducing the absorption load of the material water washing tower. A pressure regulating valve is installed on the gas outlet pipeline at the top of the deacidification tower condenser to control the pressure of the deacidification tower to prevent the pressure from being too low and the gas vaporization volume from increasing.

[0014] The crude product from the deacidification tower kettle enters the material cooler through the liquid level regulating valve, and after being cooled in the material cooler, enters the inlet pipeline of the deacidification tower feeding pump, and the crude product enters the material cooler through the outlet of the deacidification tower feeding pump; a pressure transmitter is installed on the outlet pipeline of the deacidification tower feeding pump, and the pressure of the outlet pipeline of the deacidification tower feeding pump is interlocked with the liquid level regulating valve installed on the discharge pipeline of the deacidification tower kettle. When the deacidification tower feeding pump is not pumping and there is no pressure in the pump outlet pipeline, the liquid level regulating valve of the discharge pipeline of the deacidification tower kettle is interlocked and closed to prevent the material of the liquid phase water washing tower from flowing back to the deacidification tower kettle; when the liquid level regulating valve of the discharge pipeline of the deacidification tower kettle is closed, the deacidification tower feeding pump is interlocked and stopped to prevent the deacidification tower feeding pump from running idle due to lack of liquid and damaging the pump body.

[0015] The acidic material in the deacidification tower kettle is cooled by the deacidification tower feed pump and the material cooler and then enters the upper part of the material water washing tower. Fresh tap water is cooled by frozen brine and then pumped into the bottom of the material water washing tower at a controlled flow rate. Hydrogen chloride and hydrogen fluoride are dissolved in water, while trifluorotrichloroethane is insoluble in water. The water washing liquid and crude trifluorotrichloroethane are stratified in the material water washing tower. The water washing liquid accumulates in the upper part, and the crude trifluorotrichloroethane accumulates in the lower part. The crude trifluorotrichloroethane in the lower part overflows to the upper part of the material alkali washing tower through the overflow pipe. The alkali washing liquid in the alkali washing circulation tank is pumped to the bottom of the material alkali washing tower through the alkali washing circulation pump. The crude product and the alkali washing liquid are contacted and stratified in countercurrent. The alkali washing liquid accumulates in the upper part and overflows to the alkali washing circulation tank through the overflow pipe. Trifluorotrichloroethane accumulates in the lower part and overflows to the upper part of the water distributor through the overflow pipe. Fresh tap water is added to the bottom of the water separator, and trichlorotrifluoroethane contacts with water in countercurrent and separates into layers. Trichlorotrifluoroethane accumulates at the bottom and overflows into the coarse material intermediate tank through the overflow pipe.

[0016] The acidic material in the deacidification tower kettle enters the material cooler for cooling through the liquid level regulating valve, and is then transported to the material cooler by the deacidification tower feed pump for cooling and then enters the upper part of the material water washing tower. The material water washing tower is made of PP material, and the deacidification tower feed pump is made of fluorine-lined material; the crude product temperature of the deacidification tower kettle is relatively high. In order to extend the service life of the material water washing tower and the deacidification tower feed pump, the material entering the material water washing tower and the deacidification tower feed pump needs to be cooled; the material cooler is cooled by a shell and tube heat exchanger, and the cooling medium is chilled brine.

[0017] The acidic material from the material cooler is cooled by the material cooler under the pressure of the deacidification tower pump and then enters the upper feed port of the material washing tower. The acidic material contains trace amounts of hydrogen fluoride and hydrogen chloride, which are further deacidified in the material washing tower. Fresh tap water is continuously added to the bottom of the material washing tower. The water supply pipeline adopts a U-shaped elbow to prevent material backflow. The water supply pipeline is equipped with a tap water flow meter and a flow regulating valve to control the concentration of the by-product hydrochloric acid by controlling the tap water flow. Hydrogen fluoride and hydrogen chloride are very soluble. In water, trifluorotrichloroethane is insoluble in water, and its relative density (water) is 1.579. Trifluorotrichloroethane in the acidic material contacts with water in countercurrent to form layers, and trifluorotrichloroethane sinks to the bottom of the material water washing tower, and overflows to the material alkali washing tower through the overflow pipe; trace hydrogen fluoride and hydrogen chloride in the acidic material dissolve in water, accumulate in the upper part of the material water washing tower, and overflow to the gas phase water washing tower through the overflow pipe at the top of the material water washing tower as washing liquid. The gas phase water washing tower does not need to be supplemented with fresh tap water, and the concentration of the by-product hydrochloric acid is easy to control.

[0018] The tap water is cooled by the water cooler and then enters the material washing tower; the material washing tower is made of PP material; the heat release of hydrogen fluoride, hydrogen chloride gas and water will cause the temperature of the washing liquid to rise. In order to reduce the material temperature of the material washing tower and extend the service life of the material washing tower, fresh tap water is added to the bottom of the material washing tower and condensed with frozen brine before entering the material washing tower; the water cooler is cooled by a shell and tube heat exchanger, and the cooling medium is frozen brine.

[0019] The crude product at the bottom of the material water washing tower overflows to the upper feed port of the material alkali washing tower through the overflow pipe; the alkali washing liquid in the alkali washing circulation tank enters the bottom of the material alkali washing tower through the outlet pipeline of the alkali washing circulation pump; hydrogen fluoride and hydrogen chloride are very easy to react with alkali, trifluorotrichloroethane is insoluble in water, and its relative density (water) is 1.579. The trifluorotrichloroethane in the crude product countercurrently contacts and delaminates with the alkali washing liquid, and trifluorotrichloroethane sinks to the bottom of the material alkali washing tower and overflows to the water separator through the overflow pipe; the trace amount of hydrogen fluoride and hydrogen chloride in the crude product reacts when countercurrently contacting with the alkali washing liquid, accumulates in the upper part of the material alkali washing tower, and flows into the alkali washing circulation tank through the overflow pipe at the top of the material alkali washing tower. The alkali washing liquid in the alkali washing circulation tank is transported to the bottom of the material alkali washing tower through the alkali washing circulation pump.

[0020] The alkali washing liquid of the material alkali washing tower flows into the alkali washing circulation tank through the top overflow pipe; the alkali washing liquid of the alkali washing circulation tank is transported to the bottom of the material alkali washing tower by the alkali washing circulation pump, and the pipeline adopts a U-shaped elbow to prevent the material from flowing back; the alkali washing circulation tank is installed with a pH value detector and remotely transmitted to the DCS system; when the pH value is lower than the specified value, fresh tap water and liquid alkali are added.

[0021] The crude product at the bottom of the material alkali washing tower overflows to the top of the water distributor through the overflow pipe for further stratification; fresh tap water enters from the bottom of the water distributor, and the water supply pipeline adopts a U-shaped elbow to prevent material backflow; the crude product and tap water countercurrent contact stratification; the water supply pipeline is equipped with a tap water flow meter and a flow regulating valve to control a certain tap water flow to control the acidic material content in the crude product. The liquid at the top of the water distributor overflows to the wastewater tank, and the crude product at the bottom overflows to the coarse material intermediate tank.

[0022] Beneficial effects: The present invention is applied to the trifluorotrichloroethane deacidification system, which not only reduces the amount of tap water used, makes the water washing and alkali washing systems easy to operate, and stably controls the concentration of hydrochloric acid, but also reduces the acidic material content of the product trifluorotrichloroethane and improves the product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the device of the present invention;

[0024] As shown in the figure: cryogenic condenser 1, circulation tower 2, stratification tank 3, acidic material receiving tank 4, deacidification tower 5, deacidification tower kettle 6, deacidification tower condenser 7, deacidification tower feed pump 8, material cooler 9, material water washing tower 10, water cooler 11, material alkali washing tower 12, alkali washing circulation pump 13, alkali washing circulation tank 14, water separator 15. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] A trifluorotrichloroethane deacidification device comprises a circulation tower 2, an acidic material receiving tank 4, a cryogenic condenser 1, a stratification tank 3, a material cooler 9, a deacidification tower kettle 6, a deacidification tower 5, a deacidification tower condenser 7, a deacidification tower feed pump 8, a material water washing tower 10, a water cooler 11, a material alkali washing tower 12, an alkali washing circulation pump 13, an alkali washing circulation tank 14, and a water separator 15.

[0027] The cryogenic condenser 1 is connected to the circulation tower 2, and the condensate of the cryogenic condenser 1 overflows to the feeding pipe in the middle of the circulation tower 2; the outlet gas of the trifluorotrichloroethane reaction reflux tower condenser is condensed by the pre-cooling, inter-cooling and tail cooling condensers, and the uncondensed gas enters the cryogenic condenser 1 for further condensation; the cryogenic condenser 1 is cooled by Freon. Due to the different boiling points, hydrogen fluoride is 19.5℃, trifluorotrichloroethane is 47℃, and hydrogen chloride is -85℃, most of the hydrogen fluoride, trifluorotrichloroethane and part of the hydrogen chloride in the gas are condensed, and the uncondensed hydrogen chloride gas and trace hydrogen fluoride and trifluorotrichloroethane enter the gas phase water washing and alkali washing system for treatment. The condensate condensed by the cryogenic condenser 1 enters the circulation tower 2.

[0028] The condensed liquid from each condenser enters the circulation tower 2. The tower body of the circulation tower 2 is insulated with rock wool, and the tower kettle is insulated with frozen brine. At the same time, the pressure of the circulation tower 2 is controlled at about 0.55KPa to prevent the hydrogen fluoride and trichlorotrifluoroethane in the tower kettle from escaping in large quantities. The tower body of the circulation tower 2 is equipped with packing. During the rising process of the tower body packing layer, part of the gas escaping from the tower kettle liquid is condensed by the condensed liquid flowing down from the top of the tower, and the uncondensed gas enters the deep cold condenser 1 for further condensation. The circulation tower 2 and the stratification tank 3 use pipelines to balance the pressure, and the liquid at the bottom of the circulation tower 2 enters the stratification tank 3 through the overflow pipe.

[0029] The circulation tower 2, the layering tank 3 and the acidic material receiving tank 4 are connected through a gas phase balance pipe, the circulation tower 2 and the layering tank 3 are connected, the layering tank 3 and the acidic material receiving tank 4 are connected, and the upper part of the layering tank 3 is connected with a dehydrogen fluoride recovery tank; the circulation tower 2, the layering tank 3 and the acidic material receiving tank 4 use a balance pipeline to balance the pressure, and the pressure is controlled to be about 0.55MPa to prevent the material from gasifying, and the material overflows to the lower end equipment through the overflow pipe; the condensate of the circulation tower 2 overflows to the layering tank 3, the condensate is layered in the layering tank 3, hydrogen fluoride accumulates in the upper part of the layering tank 3, trifluorotrichloroethane accumulates in the lower part of the layering tank 3, the upper hydrogen fluoride overflows to the hydrogen fluoride recovery tank, and the lower trifluorotrichloroethane contains hydrogen chloride and a trace of hydrogen fluoride. The acidic material in the acidic material receiving tank 4 is pressed into the middle feeding pipe of the deacidification tower 5 under the action of pressure after the liquid level is controlled by the liquid level regulating valve.

[0030] The liquid overflow at the bottom of the circulation tower 2 enters the layering tank 3. Based on the principle that hydrogen fluoride, hydrogen chloride and crude trifluorotrichloroethane are immiscible and have different densities, the relative density (water) of hydrogen fluoride is 1.15, the relative density (water) of hydrogen chloride is 1.19, and the relative density (water) of trifluorotrichloroethane is 1.579. Hydrogen fluoride, hydrogen chloride and trifluorotrichloroethane are layered in the layering tank 3, with hydrogen fluoride accumulating at the upper part, trifluorotrichloroethane accumulating at the lower part, and a trace amount of hydrogen chloride accumulating in the middle. The layering tank 3 and the acidic material receiving tank 4 use pipelines to balance the pressure, and the pressure of the layering tank 3 is controlled at about 0.55 KPa to prevent gasification. At the same time, the crude trifluorotrichloroethane at the bottom of the layering tank 3 enters the acidic material receiving tank 4 through the overflow pipe.

[0031] The liquid at the bottom of the stratification tank 3 enters the acidic material receiving tank 4 through the overflow pipe, and the gas in the acidic material receiving tank 4 enters the stratification tank 3. The acidic material receiving tank 4 and the stratification tank 3 use pipelines to balance the pressure, and the pressure of the acidic material receiving tank 4 is controlled at about 0.55KPa to prevent gas from gasification. At the same time, a liquid level regulating valve is installed on the discharge pipeline of the acidic material receiving tank 4. Under the action of pressure, the acidic material in the acidic material receiving tank 4 controls the liquid level to about 520mm, and the acidic material in the acidic material receiving tank 4 enters the deacidification tower 5 through the liquid level regulating valve.

[0032] A deacidification tower 5 is provided on the top of the deacidification tower kettle 6, and a deacidification tower condenser 7 is provided on the top of the deacidification tower 5. The deacidification tower kettle 6 is connected to the acidic material receiving tank 4. The deacidification tower kettle 6 is heated by steam. After the acidic material is heated in the deacidification tower kettle 6, hydrogen chloride, hydrogen fluoride and part of trifluorotrichloroethane are gasified and rise to the deacidification tower 5. Most of trifluorotrichloroethane is cooled by the cold acidic material in the middle of the deacidification tower 5. Hydrogen chloride, hydrogen fluoride and a trace amount of trifluorotrichloroethane gas rise to the deacidification tower condenser 7, trifluorotrichloroethane is condensed, and most of hydrogen chloride and hydrogen fluoride enter the gas phase water washing system for absorption through the outlet pipeline of the deacidification tower condenser 7.

[0033] The acidic material in the acidic material receiving tank 4 enters the middle feed port of the deacidification tower 5 through the liquid level regulating valve. The acidic material mainly comprises trichlorotrifluoroethane, hydrogen chloride and a trace amount of hydrogen fluoride. The acidic material contacts the hot air flow rising below the deacidification tower 5 in countercurrent through the packing layer. The cold acidic material is heated, and a large amount of hydrogen chloride and a trace amount of hydrogen fluoride in the acidic material are gasified and rise. The hot air flow contains trichlorotrifluoroethane, hydrogen chloride and hydrogen fluoride. Most of the trichlorotrifluoroethane in the hot air flow is cooled down by the cold acidic material and returns to the deacidification tower kettle 6 along with the acidic material at the feed port. The uncondensed hydrogen chloride, hydrogen fluoride gas and a trace amount of trichlorotrifluoroethane gas in the hot air flow rise to the deacidification tower condenser 7.

[0034] A deacidification tower feed pump 8 and a material cooler 9 are provided between the deacidification tower kettle 6 and the material water washing tower 10. The upper part of the material water washing tower 10 is connected to the degassing water washing system, and the lower part of the material water washing tower 10 is connected to the material alkali washing tower 12. The material alkali washing tower 12 and the alkali washing circulation tank 14 are connected through an alkali washing circulation pump 13. A water cooler 11 is provided between the material water washing tower 10 and the alkali washing circulation tank 13. The water cooler 11 is connected to a water separator 15, and the alkali washing circulation tank 13 is connected to the water separator 15. The lower part of the water separator 15 is connected to the coarse material intermediate tank, and the upper part of the water separator 15 is connected to the waste water tank.

[0035] The deacidification tower kettle 6 is heated by passing steam through the jacket, and a steam regulating valve is installed on the steam inlet pipeline to control the temperature of the deacidification tower kettle 6. After the acidic material at the bottom of the kettle is heated, the hydrogen chloride, hydrogen fluoride and part of trifluorotrichloroethane in the acidic material are gasified, and the hot air flow rises to the deacidification tower 5. The acidic material at the feed port in the middle of the deacidification tower 5 is buffered by the packing layer and the condensate after cooling part of the hot air flow enters the deacidification tower kettle 6 together, reducing the content of hydrogen chloride and hydrogen fluoride in the acidic material. A liquid level regulating valve is installed on the discharge pipeline of the deacidification tower kettle 6 to control a certain liquid level. The crude product of the deacidification tower kettle 6 enters the inlet pipeline of the deacidification tower feed pump 8 through the liquid level regulating valve.

[0036] The uncondensed hydrogen chloride and trace amounts of hydrogen fluoride and trichlorotrifluoroethane gas at the feed port of the deacidification tower 5 rise to the deacidification tower condenser 7; a cooling water flow regulating valve is installed on the deacidification tower condenser 7, and the top temperature of the deacidification tower condenser 7 is controlled by adjusting the flow rate of cooling water of the deacidification tower condenser 7; most of the trichlorotrifluoroethane and trace amounts of hydrogen fluoride in the hot gas flow condense and return to the deacidification tower kettle 6, and the uncondensed hydrogen chloride enters the gas phase water washing system, reducing the absorption load of the material water washing tower 10. A pressure regulating valve is installed on the gas outlet pipeline at the top of the deacidification tower condenser 7 to control the pressure of the deacidification tower 5 to prevent the pressure from being too low and the gasification amount from increasing.

[0037] The crude product from the deacidification tower kettle 6 enters the material cooler for cooling 9 through the liquid level regulating valve, and then enters the inlet pipeline of the deacidification tower feeding pump 8, and the crude product enters the material cooler 9 through the outlet of the deacidification tower feeding pump 8; a pressure transmitter is installed on the outlet pipeline of the deacidification tower feeding pump 8, and the pressure of the outlet pipeline of the deacidification tower feeding pump 8 is interlocked with the liquid level regulating valve installed on the discharge pipeline of the deacidification tower kettle 6. When the deacidification tower feeding pump 8 is not pumping and there is no pressure in the pump outlet pipeline, the liquid level regulating valve of the discharge pipeline of the deacidification tower kettle 6 is interlocked and closed to prevent the material of the liquid phase water washing tower from flowing back to the deacidification tower kettle 6; when the liquid level regulating valve of the discharge pipeline of the deacidification tower kettle 6 is closed, the deacidification tower feeding pump 8 is interlocked and stopped to prevent the deacidification tower feeding pump 8 from idling due to lack of liquid and damaging the pump body.

[0038] The acidic material in the deacidification tower kettle 6 is cooled by the deacidification tower feed pump 8 and the material cooler 9 and then enters the upper part of the material water washing tower 10. Fresh tap water is cooled by frozen brine and then pumped into the bottom of the material water washing tower 10 at a controlled flow rate. Hydrogen chloride and hydrogen fluoride are dissolved in water, and trifluorotrichloroethane is insoluble in water. The water washing liquid and the crude trifluorotrichloroethane are stratified in the material water washing tower. The water washing liquid accumulates in the upper part, and the crude trifluorotrichloroethane accumulates in the lower part. The crude trifluorotrichloroethane in the lower part overflows to the upper part of the material alkali washing tower 12 through the overflow pipe. The alkali washing liquid in the alkali washing circulation tank 14 is pumped to the bottom of the material alkali washing tower 12 through the alkali washing circulation pump 13. The crude product and the alkali washing liquid are contacted and stratified in countercurrent. The alkali washing liquid accumulates in the upper part and overflows to the alkali washing circulation tank 14 through the overflow pipe. The trifluorotrichloroethane accumulates in the lower part and overflows to the upper part of the water separator 15 through the overflow pipe. Fresh tap water is added to the bottom of the water separator 15, trifluorotrichloroethane contacts with water in countercurrent and delaminates, trifluorotrichloroethane accumulates at the bottom and overflows to the coarse material intermediate tank through the overflow pipe.

[0039] The acidic material in the deacidification tower kettle 6 is transported to the material cooler 9 for cooling through the deacidification tower feed pump 8. The material water washing tower 10 is made of PP material, and the temperature of the material water washing tower 10 cannot exceed 80°C; the crude product temperature of the deacidification tower kettle 6 is between 62 and 74°C. In order to extend the service life of the material water washing tower 10, the material entering the material water washing tower 10 needs to be cooled; the material cooler 9 is cooled by a shell and tube heat exchanger, and the cooling medium is chilled brine.

[0040] The acidic material in the material cooler 9 is cooled under the pressure of the deacidification tower pump 8 and enters the upper feed port of the material washing tower 10; the acidic material contains trace amounts of hydrogen fluoride and hydrogen chloride, which are further deacidified in the material washing tower 10; fresh tap water is continuously added to the bottom of the material washing tower 10, and the water supply pipeline adopts a U-shaped elbow to prevent material backflow. The water supply pipeline is equipped with a tap water flow meter and a flow regulating valve to control the concentration of the by-product hydrochloric acid by controlling the tap water flow; hydrogen fluoride and hydrogen chloride are easily soluble in water. In the process, trifluorotrichloroethane is insoluble in water, and its relative density (water) is 1.579. Trifluorotrichloroethane in the acidic material contacts with water in countercurrent to form a stratum. Trifluorotrichloroethane sinks to the bottom of the material water washing tower 10, and overflows to the material alkali washing tower 12 through the overflow pipe. Trace amounts of hydrogen fluoride and hydrogen chloride in the acidic material dissolve in water, accumulate in the upper part of the material water washing tower 10, and overflow to the gas phase water washing tower as washing liquid through the overflow pipe at the top of the material water washing tower 10. The gas phase water washing tower does not need to be supplemented with fresh tap water, and the concentration of the byproduct hydrochloric acid is easy to control.

[0041] The tap water is cooled by the water cooler and then enters the material water washing tower 10; the material water washing tower 10 is made of PP material, and the temperature cannot exceed 80°C; the heat release of hydrogen fluoride and hydrogen chloride gas with water will cause the temperature of the water washing liquid to rise. In order to reduce the material temperature of the material water washing tower 10 and extend the service life of the material water washing tower 10, fresh tap water is added to the bottom of the material water washing tower 10 and condensed with frozen brine before entering the material water washing tower 10; the water cooler 11 is cooled by a shell and tube heat exchanger, and the cooling medium is frozen brine.

[0042] The crude product at the bottom of the material water washing tower 10 overflows to the upper feed port of the material alkali washing tower 12 through the overflow pipe; the alkali washing liquid in the alkali washing circulation tank 14 enters the bottom of the material alkali washing tower 12 through the outlet pipeline of the alkali washing circulation pump 13; hydrogen fluoride and hydrogen chloride are very easy to react with alkali, trifluorotrichloroethane is insoluble in water, and the relative density (water) is 1.579. The trifluorotrichloroethane in the crude product countercurrently contacts and delaminates with the alkali washing liquid, and the trifluorotrichloroethane sinks to the bottom of the material alkali washing tower 12 and overflows to the water separator 15 through the overflow pipe; the trace amount of hydrogen fluoride and hydrogen chloride in the crude product reacts when countercurrently contacting with the alkali washing liquid, accumulates in the upper part of the material alkali washing tower 12, and flows into the alkali washing circulation tank 14 through the overflow pipe at the top of the material alkali washing tower 12. The alkali washing liquid in the alkali washing circulation tank 14 is transported to the bottom of the material alkali washing tower 12 through the alkali washing circulation pump 13.

[0043] The alkali washing liquid of the material alkali washing tower 12 flows into the alkali washing circulation tank 14 through the top overflow pipe; the alkali washing liquid of the alkali washing circulation tank 14 is transported to the bottom of the material alkali washing tower 12 through the alkali washing circulation pump 13, and the pipeline adopts a U-shaped elbow to prevent the material from flowing back; the alkali washing circulation tank 14 is equipped with a pH value detector and remotely transmits it to the DCS system; when the pH value is lower than 9, fresh tap water and liquid alkali are added.

[0044] The crude product at the bottom of the material alkali washing tower 12 overflows through the overflow pipe to the top of the water divider 15 for further stratification; fresh tap water enters from the bottom of the water divider 15, and the water supply pipeline adopts a U-shaped elbow to prevent material backflow; the crude product and the tap water are countercurrently contacted and stratified; the water supply pipeline is equipped with a tap water flow meter and a flow regulating valve to control a certain tap water flow to control the acidic material content in the crude product. The liquid at the top of the water divider 15 overflows to the wastewater tank, and the crude product at the bottom overflows to the coarse material intermediate tank.

[0045] When an element is referred to as being “fixed to” or “disposed on” another element, it may be directly on the other element or indirectly on the other element, and when an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0046] The directional terms such as left, right, up, down, etc. in this embodiment are merely relative concepts or are based on the normal use state of the product and should not be considered as restrictive.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A trifluorotrichloroethane deacidification device, Features: Including circulating tower, acid material receiving tank, cryogenic condenser, stratification tank, material cooler, deacidification tower kettle, deacidification tower, deacidification tower condenser, deacidification tower feed pump, material water washing tower, water cooler, material alkali washing tower, alkali washing circulating pump, alkali washing circulating tank, water separator; The cryogenic condenser is connected to the circulation tower, the circulation tower, the stratification tank and the acidic material receiving tank are connected through a gas phase balance pipe, the circulation tower and the stratification tank are connected, the lower part of the stratification tank is connected to the acidic material receiving tank, and the upper part of the stratification tank is connected to a dehydrogen fluoride recovery tank; A deacidification tower is provided on the upper part of the deacidification tower kettle, a deacidification tower condenser is provided on the upper part of the deacidification tower, and the deacidification tower kettle is connected to the acidic material receiving tank; A deacidification tower feed pump and a material cooler are provided between the deacidification tower kettle and the material water washing tower, the upper part of the material water washing tower is connected to the lower part of the gas phase water washing system, the lower part of the material water washing tower is connected to the upper part of the material alkali washing tower, the lower part of the material alkali washing tower is connected to the alkali washing circulation tank through the alkali washing circulation pump, a water cooler is provided on the water replenishment pipeline at the lower part of the material water washing tower, the lower part of the material alkali washing tower is connected to the upper part of the water separator, the lower part of the water separator is connected to the coarse material intermediate tank, and the upper part of the water separator is connected to the wastewater tank; The circulating tower body is insulated with rock wool, the circulating tower kettle is insulated with frozen brine, and the circulating tower body is equipped with fillers; The deacidification tower kettle is heated by passing steam through a jacket, and a steam regulating valve is installed on the steam inlet pipeline to automatically control the temperature of the deacidification tower kettle; A cooling water flow regulating valve is installed on the deacidification tower condenser, and the cooling water uses frozen brine. The top temperature of the deacidification tower condenser is controlled by adjusting the flow rate of the cooling water of the deacidification tower condenser; The gas outlet pipeline at the top of the deacidification tower condenser is equipped with a pressure regulating valve to automatically control the pressure of the deacidification tower; The acidic material in the deacidification tower kettle is cooled by the deacidification tower feed pump and the material cooler and then enters the upper part of the material water washing tower. Fresh tap water is cooled by the water cooler and then pumped into the bottom of the material water washing tower at a controlled flow rate. The water cooler is cooled by refrigerated brine, and the water supply pipeline is a U-shaped elbow. Hydrogen chloride and hydrogen fluoride are soluble in water, trifluorotrichloroethane is insoluble in water, and the water washing liquid and crude trifluorotrichloroethane are stratified in the material water washing tower. The water washing liquid accumulates in the upper part, and the crude trifluorotrichloroethane accumulates in the lower part. The crude trifluorotrichloroethane in the lower part overflows to the upper part of the material alkali washing tower through the overflow pipe. The alkali washing liquid in the alkali washing circulation tank is pumped to the bottom of the material alkali washing tower through the alkali washing circulation pump. The crude product and the alkali washing liquid are contacted and stratified in countercurrent. The alkali washing liquid accumulates in the upper part and overflows to the alkali washing circulation tank through the overflow pipe. The trifluorotrichloroethane accumulates in the lower part and overflows to the upper part of the water separator through the overflow pipe for further stratification. Fresh tap water is added to the bottom of the water distributor, and the water supply pipeline adopts a U-shaped elbow pipe; trifluorotrichloroethane contacts with water in countercurrent and is stratified. Trifluorotrichloroethane accumulates in the lower part and overflows to the coarse material intermediate tank through the overflow pipe.

2. A trifluorotrichloroethane deacidification device according to claim 1, Features: The outlet pipeline of the deacidification tower feeding pump is installed with a pressure transmitter, and the pressure of the outlet pipeline of the deacidification tower feeding pump is interlocked with the liquid level regulating valve installed on the deacidification tower kettle discharge pipeline. When the deacidification tower feeding pump is not pumping and there is no pressure in the pump outlet pipeline, the liquid level regulating valve of the deacidification tower kettle discharge pipeline is interlocked and closed to prevent the material of the liquid phase water washing tower from flowing back to the deacidification tower kettle; when the liquid level regulating valve of the deacidification tower kettle discharge pipeline is closed, the deacidification tower feeding pump is interlocked and stopped to prevent the deacidification tower feeding pump from idling due to lack of liquid and damaging the pump body.

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