Hydrogen chloride gas flow control device for 4, 4 '-dichloromethyl biphenyl

Abstract

The utility model relates to a hydrogen chloride gas flow control device for 4, 4 '-dichloromethyl biphenyl, which comprises a hydrochloric acid tank, a concentrated sulfuric acid tank, a hydrogen chloride gas generation tank, a condenser and a hydrogen chloride gas buffer tank, the output ends of the hydrochloric acid tank and the concentrated sulfuric acid tank are communicated with the input end of the hydrogen chloride gas generation tank through pipelines, the gas output port of the hydrogen chloride gas generation tank is communicated with the input end of the condenser through a pipeline, and the output end of the condenser is communicated with the input end of the hydrogen chloride gas buffer tank through a pipeline; a gas conveying pipe is arranged on the hydrogen chloride gas buffer tank; the output end of the hydrochloric acid tank and the output end of the concentrated sulfuric acid tank are higher than the input end of the hydrogen chloride gas generation tank. According to the utility model, the flow output of hydrogen chloride gas can be quickly and accurately adjusted and controlled according to the synthesis condition of 4, 4 '-dichloro-methyl biphenyl, so as to meet the flow requirement of the hydrogen chloride gas in the synthesis of 4, 4'-dichloro-methyl biphenyl.

Description

Technical Field

[0001] The utility model relates to the technical field of chemical equipment, in particular to a hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl. Background Art

[0002] 4,4'-Bis(chloromethyl)biphenyl is an important organic synthesis intermediate, which can be used to synthesize fluorescent brightener FP and fluorescent brightener CBSX. In the synthesis of 4,4'-bis(chloromethyl)biphenyl, polyformaldehyde, biphenyl and hydrogen chloride gas are used as raw materials and synthesized by chloromethylation reaction.

[0003] At present, in the industrial production of 4,4'-bischloromethyl biphenyl, some manufacturers directly purchase ready-made hydrogen chloride gas from chlor-alkali plants. However, when the manufacturer is far away from the chlor-alkali plant, considering the transportation cost and safety of hydrogen chloride gas, they will choose to make their own hydrogen chloride gas in the plant by combining hydrochloric acid and concentrated sulfuric acid. However, in the homemade hydrogen chloride gas, the output rate of hydrogen chloride gas is generally controlled by controlling the dripping rate of hydrochloric acid or concentrated sulfuric acid. When the demand for hydrogen chloride gas in the synthesis of 4,4'-bischloromethyl biphenyl changes, the dripping rate of hydrochloric acid or concentrated sulfuric acid is controlled. Although the dripping rate of hydrochloric acid or concentrated sulfuric acid can be controlled immediately, the mixture of hydrochloric acid and concentrated sulfuric acid in the hydrogen chloride gas generator still has hydrogen chloride gas escaping, and the flow rate demand of the bichloromethyl biphenyl reactor for hydrogen chloride gas cannot be met in time. There will be a certain delay in the flow control of hydrogen chloride gas, and the flow output of hydrogen chloride gas cannot be quickly and accurately adjusted according to the synthesis of 4,4'-bischloromethyl biphenyl. Utility Model Content

[0004] The main purpose of the utility model is to provide a hydrogen chloride gas flow control device for 4,4'-bischloromethyl biphenyl, so as to solve the problem that the hydrogen chloride gas output flow rate is not easy to adjust in time and quickly according to the reaction process of 4,4'-bischloromethyl biphenyl in the existing 4,4'-bischloromethyl biphenyl production.

[0005] To solve the above problems, the utility model is achieved as follows:

[0006] A hydrogen chloride gas flow control device for 4,4'-bischloromethyl biphenyl, comprising a hydrochloric acid tank, a concentrated sulfuric acid tank, a hydrogen chloride gas generating tank, a condenser, and a hydrogen chloride gas buffer tank; a gas outlet and a liquid discharge port are connected and arranged on the hydrogen chloride gas generating tank;

[0007] The output end of the hydrochloric acid tank and the output end of the concentrated sulfuric acid tank are both connected to the input end of the hydrogen chloride gas generating tank through a first pipeline, the gas output port of the hydrogen chloride gas generating tank is connected to the input end of the condenser through a second pipeline, the output end of the condenser is connected to the input end of the hydrogen chloride gas buffer tank through the second pipeline, and a gas delivery pipe is connected to the hydrogen chloride gas buffer tank, and a gas pressure reducing valve and a pneumatic ball valve are arranged on the gas delivery pipe;

[0008] The output end of the hydrochloric acid tank and the output end of the concentrated sulfuric acid tank are both higher than the input end of the hydrogen chloride gas generating tank.

[0009] Among them, it also includes a condensed water storage tank, the upper part of the condensed water storage tank is connected to a water inlet for holding condensed water, and the lower part of the condensed water storage tank is connected to a water outlet and a drain port; the lower part of the condenser is connected to a condensed water outlet, the condensed water outlet of the condenser is connected to the water inlet of the condensed water storage tank through a third pipeline, and the water outlet of the condensed water storage tank is connected to the hydrogen chloride gas generating tank through a third pipeline.

[0010] Wherein, a check valve is provided on the first pipeline connected between the hydrochloric acid tank and the hydrogen chloride gas generating tank, and on the first pipeline connected between the concentrated sulfuric acid tank and the hydrogen chloride gas generating tank.

[0011] Wherein, pneumatic ball valves are provided on the first pipeline connected between the hydrochloric acid tank and the hydrogen chloride gas generating tank, and on the first pipeline connected between the concentrated sulfuric acid tank and the hydrogen chloride gas generating tank.

[0012] Wherein, a pneumatic ball valve is arranged on the third pipeline connected between the condensed water storage tank and the hydrogen chloride gas generating tank.

[0013] Wherein, a condensate discharge pipe is connected to the discharge port of the condensate storage tank, and a pneumatic ball valve is arranged on the condensate discharge pipe.

[0014] Wherein, the liquid discharge port of the hydrogen chloride gas generating tank is connected to a liquid storage tank through the first pipeline.

[0015] Wherein, a stirring assembly is arranged inside the hydrogen chloride gas generating tank.

[0016] Wherein, the stirring assembly includes a rotating shaft vertically arranged at the central axis of the hydrogen chloride gas generating tank, and a stirring blade fixedly arranged at the bottom of the rotating shaft.

[0017] Wherein, a heat-insulating layer is attached to the outer side of the hydrogen chloride gas generating tank.

[0018] The beneficial effects of this application are:

[0019] The output end of the condenser of the utility model is connected with the input end of the hydrogen chloride gas buffer tank through the second pipeline, and a certain amount of dry hydrogen chloride gas can be temporarily stored through the hydrogen chloride gas buffer tank. When it is necessary to provide hydrogen chloride gas to the biphenyl reactor (a device for producing synthetic bischloromethyl biphenyl), and the generation rate of hydrogen chloride gas has not yet reached the demand, the hydrogen chloride gas can be temporarily provided by the hydrogen chloride gas buffer tank. When it is not necessary to provide hydrogen chloride gas to the biphenyl reactor, although the valves (pneumatic ball valve and check valve) of the hydrochloric acid tank and the concentrated sulfuric acid tank can be closed to stop the injection of concentrated sulfuric acid and dilute hydrochloric acid into the hydrogen chloride gas generating tank, the reaction in the hydrogen chloride gas generating tank cannot be stopped immediately. At this time, the generated hydrogen chloride gas can be temporarily stored in the hydrogen chloride gas buffer tank for use when the biphenyl production is started next time.

[0020] In summary, in the present invention, when the biphenyl reactor does not need hydrogen chloride gas or the flow demand for hydrogen chloride gas changes, the hydrogen chloride gas supply in the hydrogen chloride gas buffer tank can be timely controlled to meet the flow demand of the biphenyl reactor for hydrogen chloride gas. The present invention can quickly and accurately adjust and control the flow output of hydrogen chloride gas according to the synthesis of 4,4'-bischloromethyl biphenyl to meet the flow demand of hydrogen chloride gas in the synthesis of 4,4'-bischloromethyl biphenyl. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] Figure 1 It is a structural schematic diagram of the utility model.

[0023] Description of Reference Numerals

[0024] 1. Hydrochloric acid tank; 11. Hydrochloric acid outlet; 2. Concentrated sulfuric acid tank; 21. Concentrated sulfuric acid outlet; 3. Hydrogen chloride gas generator tank; 31. Gas outlet; 32. Drain; 33. Generator body; 341. Rotating shaft; 342. Stirring blades; 35. Insulation layer; 36. Liquid inlet; 37. Adjusting water inlet; 38. Liquid storage tank; 4. Condenser; 41. Gas inlet; 42. Gas outlet; 43. Condensate outlet; 5. Hydrogen chloride gas buffer tank; 51. Air inlet pipe; 61. First pipeline; 62. Second pipeline; 63. Third pipeline; 7. Gas delivery pipe; 81. Gas pressure reducing valve; 82. Pneumatic ball valve; 83. Check valve; 9. Condensate storage tank; 91. Water inlet; 92. Water outlet; 93. Discharge port; 94. Condensate discharge pipe. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0026] like Figure 1 As shown, a hydrogen chloride gas flow control device for 4,4'-bischloromethyl biphenyl of the utility model comprises a hydrochloric acid tank 1, a concentrated sulfuric acid tank 2, a hydrogen chloride gas generating tank 3, a condenser 4, and a hydrogen chloride gas buffer tank 5.

[0027] The hydrogen chloride gas generating tank 3 is provided with a gas outlet 31 and a liquid discharge port 32 in communication. In the present embodiment, the hydrogen chloride gas generating tank 3 comprises a generating tank body 33, the generating tank body 33 is vertically arranged, the gas outlet 31 is communicated and arranged at the top of the generating tank body 33, and the liquid discharge port 32 is communicated and arranged at the bottom of the generating tank body 33. A stirring assembly is arranged inside the hydrogen chloride gas generating tank 3, the stirring assembly comprises a rotating shaft 341 vertically arranged at the central axis of the hydrogen chloride gas generating tank 3, and a stirring blade 342 fixedly arranged at the bottom of the rotating shaft 341, the top end of the rotating shaft 341 extends upward to the outside of the hydrogen chloride gas generating tank 3 and is fixedly connected to a driving motor for driving the rotating shaft 341 to rotate. The arrangement of the stirring assembly can further fully mix the hydrochloric acid solution with the concentrated sulfuric acid solution, thereby increasing the gas production of hydrogen chloride gas. In addition, a heat-insulating layer 35 is provided on the outer side of the hydrogen chloride gas generating tank 3. When the concentrated sulfuric acid absorbs the water in the hydrochloric acid and releases heat, the heat-insulating layer 35 can prevent the heat in the hydrogen chloride gas generating tank 3 from being lost, and further promote the escape of the hydrogen chloride gas in the hydrochloric acid.

[0028] The output end of the hydrochloric acid tank 1 and the output end of the concentrated sulfuric acid tank 2 are both connected to the input end of the hydrogen chloride gas generating tank 3 through the first pipeline 61, the gas output port 31 of the hydrogen chloride gas generating tank 3 is connected to the input end of the condenser 4 through the second pipeline 62, the output end of the condenser 4 is connected to the input end of the hydrogen chloride gas buffer tank 5 through the second pipeline 62, the hydrogen chloride gas buffer tank 5 is connected to a gas delivery pipe 7, and a gas pressure reducing valve 81 and a pneumatic ball valve 82 are arranged on the gas delivery pipe 7. In this embodiment, the structure of the output end of the hydrochloric acid tank 1 and the output end of the concentrated sulfuric acid tank 2 is as follows: the hydrochloric acid liquid outlet 11 is connected to the bottom end of the hydrochloric acid tank 1, and the concentrated sulfuric acid liquid outlet 21 is connected to the bottom end of the concentrated sulfuric acid tank 2, wherein the hydrochloric acid liquid outlet 11 and the concentrated sulfuric acid liquid outlet 21 are the output ends of the hydrochloric acid tank 1 and the concentrated sulfuric acid tank 2, respectively. The structure of the input end of the hydrogen chloride gas generating tank 3 is as follows: two liquid inlets 36 are connected and arranged at the top of the generating tank body 33, and the two liquid inlets 36 are respectively used to connect the hydrochloric acid tank 1 and the concentrated sulfuric acid tank 2, and the two liquid inlets 36 are respectively the input ends of the hydrogen chloride gas generating tank 3. Among them, the input end and the output end of the condenser 4 are respectively for the entry and exit of hydrogen chloride gas, that is, the hydrogen chloride gas with water vapor enters the input end of the condenser, and under the action of the condenser, the water vapor is condensed into water, that is, the hydrogen chloride gas is dried, and the dried hydrogen chloride gas flows out from the output end of the condenser 4. In this embodiment, the input end and the output end of the condenser 4 are respectively the gas input port 41 and the gas output port 42 of the condenser, the gas input port 41 is arranged at the bottom end of the condenser 4, the gas output port 42 is arranged at the top end of the condenser 4, and the gas input port 41 and the gas output port 42 are respectively located on both sides of the central axis of the condenser 4, so that the hydrogen chloride gas can be fully cooled and dried. The internal structure of the condenser 4 is prior art and does not constitute an improvement of the present invention. The refrigerant (which is prior art) in the tube bundle in the condenser dries the gas mixed with water vapor entering the condenser, and the water vapor is condensed into water and discharged. The dried gas is output to the hydrogen chloride gas buffer tank 5. The structure of the input end of the hydrogen chloride gas buffer tank 5 is as follows: an air inlet pipe 51 is connected to the top of the hydrogen chloride gas buffer tank 5, and the air inlet pipe 51 is the input end of the hydrogen chloride gas buffer tank 5.

[0029] like Figure 1 As shown, in this embodiment, the output end of the hydrochloric acid tank 1 and the output end of the concentrated sulfuric acid tank 2 are both higher than the input end of the hydrogen chloride gas generating tank 3. In addition, the installation heights of the hydrochloric acid tank 1 and the concentrated sulfuric acid tank 2 are both higher than the top of the hydrogen chloride gas generating tank 3. This has the following effects: since the hydrochloric acid is stored in the hydrochloric acid tank 1, it can inject the hydrochloric acid solution into the hydrogen chloride gas generating tank 3 at a certain rate by gravity, and no additional delivery pump is required, which reduces the cost; the concentrated sulfuric acid is stored in the concentrated sulfuric acid tank 2, and it can inject the concentrated sulfuric acid solution into the hydrogen chloride gas generating tank 3 at a certain rate by gravity.

[0030] The hydrogen chloride gas flow control device for 4,4'-bischloromethyl biphenyl of the utility model also includes a condensed water storage tank 9, the upper part of the condensed water storage tank 9 is connected to a water inlet 91 for receiving condensed water, and the lower part of the condensed water storage tank 9 is connected to a water outlet 92 and a discharge port 93. The lower part of the condenser 4 is connected to a condensed water outlet 43, and the condensed water outlet 43 of the condenser 4 is connected to the water inlet 91 of the condensed water storage tank 9 through the third pipeline 63, and the water outlet 92 of the condensed water storage tank 9 is connected to the hydrogen chloride gas generating tank 3 through the third pipeline 63. Specifically, the top of the hydrogen chloride gas generating tank 3 is connected to the regulating water inlet 37, and the water outlet 92 of the condensed water storage tank 9 is connected to the regulating water inlet 37 of the hydrogen chloride gas generating tank 3 through the third pipeline 63. In this embodiment, a condensed water discharge pipe 94 is connected to the discharge port 93 of the condensed water storage tank 9, and a pneumatic ball valve 82 is provided on the condensed water discharge pipe 94.

[0031] In this embodiment, a check valve 83 is provided on the first pipeline 61 connecting the hydrochloric acid tank 1 and the hydrogen chloride gas generating tank 3, and on the first pipeline 61 connecting the concentrated sulfuric acid tank 2 and the hydrogen chloride gas generating tank 3. The check valve 83 is used to prevent the pressure in the hydrogen chloride gas generating tank 3 from being too high, so that the hydrogen chloride gas flows back into the hydrochloric acid tank 1 or the concentrated sulfuric acid tank 2. A pneumatic ball valve 82 is provided on the first pipeline 61 connecting the hydrochloric acid tank 1 and the hydrogen chloride gas generating tank 3, and on the first pipeline 61 connecting the concentrated sulfuric acid tank 2 and the hydrogen chloride gas generating tank 3.

[0032] In this embodiment, a pneumatic ball valve 82 is provided on the third pipeline 63 connected between the condensed water storage tank 9 and the hydrogen chloride gas generating tank 3, and a pneumatic ball valve 82 is provided on the condensed water discharge pipe 94. The discharge port 32 of the hydrogen chloride gas generating tank 3 is connected to the liquid storage tank 38 through the first pipeline 61, and the liquid storage tank 38 is used to collect the solution including dilute sulfuric acid and the like after the hydrogen chloride gas generating tank 3 is mixed, which can be subsequently processed and reused.

[0033] like Figure 1 As shown, the use process of the utility model is as follows: hydrochloric acid solution and concentrated sulfuric acid solution are respectively contained in the hydrochloric acid tank 1 and the concentrated sulfuric acid tank 2. Since the installation height of the hydrochloric acid tank 1 and the concentrated sulfuric acid tank 2 is higher than the top of the hydrogen chloride gas generating tank 3 (that is, the bottom ends of the hydrochloric acid tank 1 and the concentrated sulfuric acid tank 2 are both higher than the top of the hydrogen chloride gas generating tank 3), the hydrochloric acid solution and the concentrated sulfuric acid solution can flow to the hydrogen chloride gas generating tank 3 by gravity.

[0034] In the hydrogen chloride gas generating tank 3, since concentrated sulfuric acid has strong water absorption, the hydrogen chloride gas in the hydrochloric acid is easy to volatilize. When the concentrated sulfuric acid is mixed with the hydrochloric acid, the concentrated sulfuric acid dissolves in water and releases a large amount of heat. Raising the temperature can promote the volatilization of the hydrogen chloride gas, reduce its solubility, and facilitate the escape of the hydrogen chloride gas. When the concentrated sulfuric acid is mixed with the hydrochloric acid, part of the water will also be converted into water vapor. In addition, the utility model sets a stirring component in the hydrogen chloride gas generating tank, and the stirring component can make the hydrochloric acid solution and the concentrated sulfuric acid solution mix evenly, avoid excessive local temperature, and ensure the stable gas production rate.

[0035] The hydrogen chloride gas mixed with water vapor enters the condenser 4 through the second pipeline 62. Under the action of the condenser 4, the water vapor condenses into water, and the water enters the condensed water storage tank 9 through the third pipeline 63. The dried hydrogen chloride gas is output from the gas output port 42 of the condenser 4 and enters the hydrogen chloride gas buffer tank 5 through the second pipeline 62. The function of the hydrogen chloride gas buffer tank 5 is to temporarily store a certain amount of hydrogen chloride gas. When hydrogen chloride gas needs to be provided to the biphenyl reactor (a device for producing synthetic bischloromethyl biphenyl), and the generation rate of hydrogen chloride gas has not yet reached the demand, it can be temporarily provided by the hydrogen chloride gas buffer tank 5; when hydrogen chloride gas is not needed to be provided to the biphenyl reactor, the valves (pneumatic ball valve 82 and check valve 83) of the hydrochloric acid tank 1 and the concentrated sulfuric acid tank 2 are closed, and the injection of concentrated sulfuric acid and dilute hydrochloric acid into the hydrogen chloride gas generating tank 3 is stopped. However, the reaction in the hydrogen chloride gas generating tank 3 cannot be stopped immediately. The hydrogen chloride gas generated at this time can be temporarily stored in the hydrogen chloride gas buffer tank 5 and used when the biphenyl production is started next time, which also reduces the loss of hydrogen chloride gas to a certain extent. That is, when the biphenyl reactor does not need hydrogen chloride gas or the demand for hydrogen chloride gas changes, the demand flow of hydrogen chloride gas of the biphenyl reactor can be met by timely controlling the supply of hydrogen chloride gas in the hydrogen chloride gas buffer tank 5.

[0036] In addition, the water outlet 92 of the condensed water storage tank 9 is connected to the hydrogen chloride gas generating tank 3 through the third pipeline 63. The function of this setting is: when the gas production rate in the hydrogen chloride gas generating tank 3 is greater than the demand, in addition to storing the excess hydrogen chloride gas in the hydrogen chloride gas buffer tank 5, the condensed water in the condensed water storage tank 9 can also be passed into the hydrogen chloride gas generating tank 3 through the condensed water storage tank 9 to reduce the concentration of concentrated sulfuric acid, thereby reducing the gas production rate and further controlling the flow of hydrogen chloride gas.

[0037] Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

Claims

1. A hydrogen chloride gas flow control device for 4,4'-bischloromethyl biphenyl, characterized in that: It includes a hydrochloric acid tank, a concentrated sulfuric acid tank, a hydrogen chloride gas generating tank, a condenser, and a hydrogen chloride gas buffer tank; the hydrogen chloride gas generating tank is connected with a gas outlet and a liquid discharge outlet; The output end of the hydrochloric acid tank and the output end of the concentrated sulfuric acid tank are both connected to the input end of the hydrogen chloride gas generating tank through a first pipeline, the gas output port of the hydrogen chloride gas generating tank is connected to the input end of the condenser through a second pipeline, the output end of the condenser is connected to the input end of the hydrogen chloride gas buffer tank through the second pipeline, and a gas delivery pipe is connected to the hydrogen chloride gas buffer tank, and a gas pressure reducing valve and a pneumatic ball valve are arranged on the gas delivery pipe; The output end of the hydrochloric acid tank and the output end of the concentrated sulfuric acid tank are both higher than the input end of the hydrogen chloride gas generating tank.

2. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 1, characterized in that: It also includes a condensate storage tank, the upper part of which is connected to a water inlet for holding condensate, and the lower part of which is connected to a water outlet and a drain; the lower part of the condenser is connected to a condensate outlet, and the condensate outlet of the condenser is connected to the water inlet of the condensate storage tank through a third pipeline, and the water outlet of the condensate storage tank is connected to the hydrogen chloride gas generating tank through a third pipeline.

3. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 1, characterized in that: Check valves are provided on the first pipeline connected between the hydrochloric acid tank and the hydrogen chloride gas generating tank, and on the first pipeline connected between the concentrated sulfuric acid tank and the hydrogen chloride gas generating tank.

4. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 1, characterized in that: Pneumatic ball valves are provided on the first pipeline connected between the hydrochloric acid tank and the hydrogen chloride gas generating tank, and on the first pipeline connected between the concentrated sulfuric acid tank and the hydrogen chloride gas generating tank.

5. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 2, characterized in that: A pneumatic ball valve is provided on the third pipeline connected between the condensed water storage tank and the hydrogen chloride gas generating tank.

6. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 2, characterized in that: A condensate discharge pipe is connected to the discharge port of the condensate storage tank, and a pneumatic ball valve is arranged on the condensate discharge pipe.

7. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 1, characterized in that: The liquid discharge port of the hydrogen chloride gas generating tank is connected to a liquid storage tank through the first pipeline.

8. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 1, characterized in that: A stirring assembly is arranged inside the hydrogen chloride gas generating tank.

9. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 8, characterized in that: The stirring assembly comprises a rotating shaft vertically arranged at the central axis of the hydrogen chloride gas generating tank, and a stirring blade fixedly arranged at the bottom of the rotating shaft.

10. The hydrogen chloride gas flow control device for 4,4'-bischloromethylbiphenyl according to claim 1, characterized in that: A heat-insulating layer is attached to the outer side of the hydrogen chloride gas generating tank.

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