A solution recovery device for the production of vinylidene fluoride

Abstract

The utility model provides a kind of solution recovery device for vinylidene fluoride production, including evaporator, condenser, recovery tank, conveying pump and collection tank connected in turn;The evaporator is connected with condenser by recovery pipeline, condenser is connected with recovery tank by liquid down pipeline, recovery tank is connected with conveying pump by recovery tank outlet pipeline, conveying pump is connected with collection tank by conveying pump outlet pipeline;The condenser is equipped with water pipeline and backwater pipeline, the water pipeline is equipped with regulating valve, the liquid down pipeline is equipped with thermometer, and it is interlocked with regulating valve setting.This utility model can realize the recycling of calcium chloride solution, while recovering raw material difluoro-chloroethane, can reduce production cost, and operation is easy.

Description

Technical Field

[0001] This utility model belongs to the field of vinylidene fluoride synthesis technology, and relates to a solution recovery device for vinylidene fluoride production. Background Technology

[0002] Vinylidene fluoride (VDF) is produced using dichlorofluoroethane as raw material. The VDF is vaporized, preheated, and then cracked. The resulting high-temperature cracked gas is cooled, dusted, and then processed through a water washing tower, an alkali washing tower, and a primary compression. It is then dehydrated in a calcium chloride dehydration tower to remove moisture from the VDF. Finally, it enters a secondary compression and distillation process to obtain the finished VDF product.

[0003] After the calcium chloride dehydration tower has been running for a period of time, the calcium chloride solution absorbs moisture from vinylidene fluoride, causing the calcium chloride to become diluted. Therefore, to ensure the dehydration effect of the calcium chloride dehydration tower, the old calcium chloride solution needs to be drained and replaced with a new, high-concentration calcium chloride solution after the tower has been running for a period of time. The drained calcium chloride solution is evaporated, and some of the water is evaporated and reused. Since the cracking reaction cannot completely convert difluorochloroethane into vinylidene fluoride, calcium chloride dehydration uses -15℃ frozen brine. Under these temperature and pressure conditions, difluorochloroethane in vinylidene fluoride is easily condensed from the gas phase into a liquid phase and mixed into the calcium chloride solution in the dehydration tower, thus affecting the recovery of the calcium chloride solution. Utility Model Content

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a solution recovery device for the production of vinylidene fluoride. This device solves the problem that in the current production process of vinylidene fluoride, the calcium chloride dehydration tower easily condenses difluorochloroethane from the gas phase into liquid calcium chloride, which then mixes into the calcium chloride solution in the calcium chloride dehydration tower, thus affecting the recovery of the calcium chloride solution.

[0005] Therefore, the present invention adopts the following technical solution: A solution recovery device for the production of vinylidene fluoride includes an evaporator, a condenser, a recovery tank, a transfer pump, and a collection tank connected in sequence. The evaporator is connected to the condenser through a recovery pipe, the condenser is connected to the recovery tank through a liquid discharge pipe, the recovery tank is connected to the transfer pump through a recovery tank outlet pipe, and the transfer pump is connected to the collection tank through a transfer pump outlet pipe. The condenser is equipped with an inlet water pipe and a return water pipe. The inlet water pipe is equipped with a regulating valve, and the outlet water pipe is equipped with a thermometer, which is interlocked with the regulating valve.

[0006] The evaporator is equipped with a first level gauge and a steam pipe.

[0007] The recovery tank is equipped with a second level gauge.

[0008] Both the water supply pipe and the return water pipe are filled with -35℃ brine.

[0009] The beneficial effects of this utility model are as follows: In use, this invention heats a calcium chloride solution via a steam pipe, evaporating difluorochloroethane from the solution. The evaporated ethane then enters a condenser via a recovery pipe and is subsequently collected in a recovery tank. This process removes the difluorochloroethane from the calcium chloride solution, enabling the recycling of the calcium chloride solution and recovering the raw material difluorochloroethane. This reduces costs and is characterized by its simple structure and easy operation. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the device structure of this utility model.

[0011] In the diagram, 1-evaporator, 2-first level gauge, 3-recovery pipe, 4-water supply pipe, 5-regulating valve, 6-steam pipe, 7-condenser, 8-return water pipe, 9-thermometer, 10-second level gauge, 11-lowering pipe, 12-recovery tank, 13-recovery tank outlet pipe, 14-transfer pump, 15-transfer pump outlet pipe, 16-collection tank. Detailed Implementation

[0012] The technical solution of this utility model will be described below with reference to the accompanying drawings and implementation methods.

[0013] like Figure 1 As shown, a solution recovery device for vinylidene fluoride production includes an evaporator 1, a condenser 7, a recovery tank 12, a transfer pump 14, and a collection tank 16 connected in sequence; the evaporator 1 is equipped with a first level gauge 2 and a steam pipe 6; the first level gauge 2 is used to observe whether the difluorochloroethane in the calcium chloride solution inside the evaporator 1 has been completely evaporated.

[0014] Evaporator 1 is connected to condenser 7 via recovery pipe 3. Condenser 7 is connected to recovery tank 12 via liquid discharge pipe 11. In this embodiment, condenser 7 condenses gaseous difluorochloroethane into liquid phase and recovers it into recovery tank 12.

[0015] The condenser 7 is equipped with an inlet water pipe 4 and a return water pipe 8, both of which are supplied with -35℃ brine. The inlet water pipe 4 is equipped with a regulating valve 5, and the outlet water pipe 11 is equipped with a thermometer 9, which is interlocked with the regulating valve 5.

[0016] The recovery tank 12 is connected to the transfer pump 14 through the recovery tank outlet pipe 13, and the transfer pump 14 is connected to the collection tank 16 through the transfer pump outlet pipe 15. The recovery tank 12 is equipped with a second level gauge 10, which is used to observe the level of dichlorofluorocarbon in the recovery tank 12.

[0017] In use, the calcium chloride solution is collected by the evaporator 1, and the calcium chloride solution is heated by the steam pipe 6 to evaporate the difluorochloroethane in the calcium chloride solution. After being condensed by the condenser 7 through the recovery pipe 3, it enters the recovery tank 12 and is pumped into the collection tank 16 for reuse by the transfer pump 14.

Claims

1. A solution recovery device for vinylidene fluoride production, characterized in that, It includes an evaporator (1), a condenser (7), a recovery tank (12), a transfer pump (14), and a collection tank (16) connected in sequence. The evaporator (1) is connected to the condenser (7) through the recovery pipe (3), the condenser (7) is connected to the recovery tank (12) through the liquid discharge pipe (11), the recovery tank (12) is connected to the transfer pump (14) through the recovery tank outlet pipe (13), and the transfer pump (14) is connected to the collection tank (16) through the transfer pump outlet pipe (15). The condenser (7) is provided with a water inlet pipe (4) and a water return pipe (8). The water inlet pipe (4) is provided with a regulating valve (5), and the liquid outlet pipe (11) is provided with a thermometer (9), which is interlocked with the regulating valve (5).

2. The solution recovery device for vinylidene fluoride production according to claim 1, characterized in that, The evaporator (1) is equipped with a first level gauge (2) and a steam pipe (6).

3. A solution recovery device for vinylidene fluoride production according to claim 1, characterized in that, The recovery tank (12) is equipped with a second level gauge (10).

4. A solution recovery device for vinylidene fluoride production according to claim 1, characterized in that, Both the water supply pipe (4) and the water return pipe (8) are supplied with -35℃ brine.

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