Purification and recovery device for 1, 1-dichloroethylene production kettle bottom solution

Abstract

The utility model relates to a recovery and purification device, in particular to a purification and recovery device for 1, 1-dichloroethylene production kettle bottom liquid. The heat exchanger is connected with a rectifying tower through a uniform buffer tank; a reboiler is arranged at the bottom of the rectifying tower; the top of the rectifying tower is connected with a temporary liquid storage tank through a condenser; the temporary liquid storage tank is connected with the rectifying tower through a return pipeline and is connected with a next working section through a low-boiling-point substance output pipeline; the top of the rectifying tower is connected with the heat exchanger and a jacket gas inlet of the uniform buffer tank through pipelines; and the heat exchanger and a jacket gas outlet of the uniform buffer tank are connected with the condenser through pipelines. A low-boiling-point substance evaporated from the top of a rectifying tower is introduced into a jacket of a heat exchanger and a uniform buffer tank to perform heat exchange and heating on a kettle bottom solution before entering the rectifying tower, the kettle bottom solution is heated for the first time through the heat exchanger, the kettle bottom solution is introduced into the uniform buffer tank to be heated, stirred and homogenized again, and then uniform and stable liquid is formed and then pumped into the rectifying tower to be treated.

Description

TECHNICAL FIELD

[0001] The utility model relates to recovery purification device, concretely relates to 1, 1 -dichloroethylene production kettle bottom liquid's purification recovery device. BACKGROUND

[0002] In the production process of 1, 1 -dichloroethylene, kettle bottom liquid usually contains target product 1, 1 -dichloroethylene and various high-boiling-point impurities, such as trichloroethane, tetrachloroethane, trichloroethylene and the like. The traditional separation and purification process mainly adopts rectification technology, but due to the complex composition of kettle bottom liquid and the easy occurrence of self-polymerization reaction, the separation efficiency is often low, the energy consumption is high, and the product quality is unstable in actual production. Especially when the feed temperature fluctuates greatly, it will lead to uneven temperature field distribution in the rectification tower, seriously affecting the separation effect, and further increasing the load of the subsequent purification process.

[0003] In the prior art, a simple single-stage heat exchanger is usually used to preheat the feed, but this heating method cannot guarantee temperature uniformity, which easily causes the operation parameters of the rectification tower to fluctuate. Although some improved schemes attempt to increase the heat exchange area or optimize the heat exchange process to improve the thermal efficiency, they cannot fundamentally solve the problem of unstable operation of the rectification tower caused by uneven feed temperature. In addition, the traditional process does not fully utilize the heat energy of the tower overhead distillate, and the latent heat of a large amount of low-boiling steam is not effectively recovered, resulting in energy waste.

[0004] In terms of product quality control, conventional devices usually rely only on a single reflux ratio adjustment to ensure separation efficiency, lack secondary detection of the final product and reflux mechanism. When there is a transient operation fluctuation, it is easy to cause unqualified products to enter the downstream process, which not only affects the quality of the final product, but also may cause waste of raw materials. At the same time, the existing equipment lacks emergency measures when dealing with sudden failures, for example, the transmission pump must be shut down for maintenance once it fails, which seriously affects the continuity of production.

[0005] In addition, since 1, 1 -dichloroethylene and its associated substances are corrosive and prone to self-polymerization, the traditional process equipment often faces serious corrosion and clogging problems. Although some processes add polymerization inhibitors, they lack systematic corrosion prevention design, resulting in shortened equipment service life and increased maintenance costs. Especially when dealing with kettle bottom liquid containing trace amounts of HCl, the corrosion problem is more prominent, which directly affects the long-period stable operation of the device. UTILITY MODEL CONTENT

[0006] The utility model discloses a purification recovery device for 1, 1 -dichloroethylene production kettle bottom liquid to solve the problem of insufficient heat energy utilization of tower overhead distillate and unstable operation of the rectification tower caused by uneven feed temperature.

[0007] In order to solve the above problems, the technical scheme of the utility model is:

[0008] The utility model discloses 1,1 -dichloroethylene production kettle bottom liquid's purification recovery device, including kettle bottom liquid pipeline, the kettle bottom liquid pipeline passes through filter and connects heat exchanger, and the heat exchanger passes through even buffer tank and connects rectifying column, and the rectifying column bottom is equipped with reboiler, and the rectifying column top is connected temporary liquid storage tank through condenser, and the temporary liquid storage tank is connected rectifying column through return pipeline, and is connected next section through low -boiling substance output pipeline, and the rectifying column top is connected the jacket gas inlet of heat exchanger and even buffer tank through pipeline, and the jacket gas outlet of heat exchanger and even buffer tank is connected condenser through pipeline, the rectifying column top is equipped with tower top temperature transmitter, and the rectifying column bottom is equipped with high -boiling substance output pipeline.

[0009] The low-boiling substance evaporated from the top of the rectifying column is introduced into the jacket of the heat exchanger and the even buffer tank to heat the kettle bottom liquid before entering the rectifying column. First, the kettle bottom liquid is heated for the first time by the heat exchanger. However, the temperature of the kettle bottom liquid heated by the heat exchanger is unstable and uneven at this time. In order to solve the problem of difficult temperature control in the rectifying column, it is necessary to accurately control the uniform and stable temperature of the feed. Therefore, the kettle bottom liquid is introduced into the even buffer tank for re-heating, stirring and homogenization. Then, after forming a uniform and stable liquid, it is pumped into the rectifying column for treatment.

[0010] Further, the low-boiling substance output pipeline is provided with a detection pipeline.

[0011] Further, a reflux ratio controller is provided between the condenser and the temporary liquid storage tank. The reflux pipeline of the reflux ratio controller is connected to the feed inlet of the top of the rectifying column, and the production pipeline of the reflux ratio controller is connected to the temporary liquid storage tank.

[0012] Although the reflux ratio controller can improve the separation effect to some extent, the product quality can be controlled again before output. The unqualified product is transported back to the rectifying column for treatment, which is beneficial to further improve the product quality.

[0013] Further, the output end of the tower top temperature transmitter is electrically connected to the control end of the reflux ratio controller.

[0014] The reflux ratio is adjusted according to the deviation of the tower top temperature, which is beneficial to improve the separation effect and better control the tower top temperature.

[0015] Further, the bottom of the temporary liquid storage tank is connected to the return pipeline and the low-boiling substance output pipeline through the third transmission pump and the fourth transmission pump arranged in parallel.

[0016] Further, the temporary liquid storage tank is provided with a liquid level transmitter. The output end of the liquid level transmitter is electrically connected to the control end of the third transmission pump and the fourth transmission pump.

[0017] The bottom of the even buffer tank is connected to the rectifying column through the first transmission pump and the second transmission pump arranged in parallel.

[0018] The rectification tower bottom is connected with the reboiler through the fifth transmission pump and the sixth transmission pump arranged in parallel.

[0019] The arrangement of one transmission pump and one standby transmission pump can better cope with the emergency in the production process, and when one transmission pump fails, the other can also realize the normal production process.

[0020] When the liquid level in the temporary liquid storage tank reaches the set liquid level, the third transmission pump or the fourth transmission pump is started to output outward, and the discharged liquid is detected through the detection pipeline. When it does not meet the standard, the liquid is transported to the rectification tower through the return pipeline for re-separation through the switching of the valve. When it meets the standard, it is directly output through the low-boiling output pipeline.

[0021] The rectification tower is connected with the ammonia pipeline.

[0022] The addition of ammonia in the rectification process can prevent self-polymerization and corrosion caused by a small amount of HCl in the kettle bottom liquid during removal.

[0023] Working principle:

[0024] The kettle bottom liquid of the 1,1-dichloroethylene production kettle is transported to the rectification tower through the first transmission pump or the parallel second transmission pump through the kettle bottom liquid pipeline, and the high-boiling substances such as trichloroethane, tetrachloroethane, trichloroethylene, 1,2-dichloroethylene, and a small amount of 1,1-dichloroethylene are left at the bottom of the rectification tower. The low-boiling substance 1,1-dichloroethylene is distilled from the top of the tower, condensed by the condenser, and controlled by the reflux ratio controller, part of which enters the temporary liquid storage tank, and part of which returns to the rectification tower for further rectification and purification. When the liquid level in the temporary liquid storage tank reaches the set liquid level, the third transmission pump or the fourth transmission pump is started to output outward, and the discharged liquid is detected through the detection pipeline. When it does not meet the standard, the liquid is transported to the rectification tower through the return pipeline for re-separation through the switching of the valve. When it meets the standard, it is directly output through the low-boiling output pipeline. The high-boiling substances at the bottom of the rectification tower are circulated through the reboiler by the fifth transmission pump or the sixth transmission pump, and are output through the high-boiling output pipeline after being qualified. In the rectification process, ammonia is introduced to prevent self-polymerization and corrosion caused by a small amount of HCl in the kettle bottom liquid during removal. The low-boiling substance distilled from the top of the rectification tower is introduced into the heat exchanger and the jacket of the uniform buffer tank to heat the kettle bottom liquid before entering the rectification tower. First, the kettle bottom liquid is heated for the first time by the heat exchanger, but at this time the kettle bottom liquid heated by the heat exchanger is unstable and uneven in temperature. In order to solve the problem of difficult temperature control in the rectification tower, it is necessary to accurately control the uniform and stable temperature of the feed. Therefore, the kettle bottom liquid is introduced into the uniform buffer tank for re-heating, stirring, and homogenization, and then the uniform and stable liquid is pumped into the rectification tower for treatment. The tower top distillate after heat exchange is condensed into liquid by the condenser, saving energy.

[0025] The utility model discloses the beneficial effect as follows:

[0026] (1) the utility model discloses setting ammonia pipeline on rectifying tower, and the ammonia water can be added in rectification process to prevent self-aggregation and the corrosion caused by the small amount of HCl in the kettle bottom liquid in the removal process.

[0027] (2) the utility model discloses setting reflux ratio controller, and the reflux ratio is adjusted according to the tower top temperature deviation, is favorable to the promotion separation effect, better control tower top temperature. Reflux ratio controller can improve separation effect to a certain extent, and the product quality is again controlled to the secondary product quality, and the unqualified product is transported back to rectifying tower processing again, and it is favorable to further improving product quality.

[0028] (3) the utility model discloses that the low boiling point material of rectifying tower top evaporation is introduced into the jacket of heat exchanger and uniform buffer tank and is heated to the kettle bottom liquid before entering rectifying tower, first, the kettle bottom liquid is heated first time through heat exchanger, but the kettle bottom liquid temperature is unstable and uneven at this time after heat exchanger heating, in order to solve the problem that the temperature in rectifying tower is difficult to control, need to accurately control the temperature uniformity of feeding, so the kettle bottom liquid is introduced into uniform buffer tank and is heated again, and then the uniform stable liquid is formed and is pumped into rectifying tower and handles. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings explained here are used to provide further understanding of the utility model and constitute a part of the utility model. In the drawings:

[0030] Figure 1 It is the structure schematic diagram of the purification recovery device of 1,1-dichloroethene production kettle bottom liquid of the utility model.

[0031] In the drawing: 1, kettle bottom liquid pipeline;2, filter;3, heat exchanger;4, uniform buffer tank;5, first transmission pump;6, second transmission pump;7, rectifying tower;8, condenser;9, reflux ratio controller;901, reflux pipeline;902, production pipeline;10, temporary liquid storage tank;11, third transmission pump;12, fourth transmission pump;13, return pipeline;14, low boiling point material output pipeline;15, reboiler;16, fifth transmission pump;17, sixth transmission pump;18, detection pipeline;19, ammonia pipeline;20, high boiling point material output pipeline. DETAILED DESCRIPTION

[0032] The utility model can be understood by the following combining example.

[0033] Example

[0034] As Figure 1As shown, the purifying and recycling device for the kettle bottom liquid of 1,1-dichloroethylene production kettle comprises a kettle bottom liquid pipeline 1, the kettle bottom liquid pipeline 1 is connected with a heat exchanger 3 through a filter 2, the heat exchanger 3 is connected with a rectifying tower 7 through an even buffer tank 4, the bottom of the rectifying tower 7 is provided with a reboiler 15, the top of the rectifying tower 7 is connected with a temporary liquid storage tank 10 through a condenser 8, the temporary liquid storage tank 10 is connected with the rectifying tower 7 through a return pipeline 13, is connected with the next section through a low-boiling substance output pipeline 14, the top of the rectifying tower 7 is connected with the jacket gas inlet of the heat exchanger 3 and the even buffer tank 4 through a pipeline, the jacket gas outlet of the heat exchanger 3 and the even buffer tank 4 is connected with the condenser 8 through a pipeline, the top of the rectifying tower 7 is provided with a tower top temperature transmitter, and the bottom of the rectifying tower 7 is provided with a high-boiling substance output pipeline 20.

[0035] The low-boiling substance evaporated from the top of the rectifying tower 7 is introduced into the jacket of the heat exchanger 3 and the even buffer tank 4 to heat the kettle bottom liquid before entering the rectifying tower 7, the kettle bottom liquid is heated for the first time through the heat exchanger 3, but the temperature of the kettle bottom liquid heated through the heat exchanger 3 is unstable and uneven at this time, in order to solve the problem that the temperature in the rectifying tower 7 is difficult to control, the temperature of the feed needs to be accurately controlled to be uniform and stable, therefore, the kettle bottom liquid is introduced into the even buffer tank 4 to be heated again, stirred and homogenized, and then pumped into the rectifying tower 7 for treatment after forming a uniform and stable liquid.

[0036] It can be understood that the low-boiling substance output pipeline 14 is provided with a detection pipeline 18.

[0037] It can be understood that the condenser 8 and the temporary liquid storage tank 10 are provided with a reflux ratio controller 9, the reflux pipeline 901 of the reflux ratio controller 9 is connected with the feed inlet of the top of the rectifying tower 7, and the production pipeline 902 of the reflux ratio controller 9 is connected with the temporary liquid storage tank 10.

[0038] Although the reflux ratio controller 9 can improve the separation effect to a certain extent, the product quality is detected again before output, the unqualified product is transported back to the rectifying tower 7 for treatment again, and the product quality is further improved.

[0039] It can be understood that the output end of the tower top temperature transmitter is electrically connected with the control end of the reflux ratio controller 9.

[0040] The reflux ratio is adjusted according to the deviation of the tower top temperature, which is beneficial to improving the separation effect and better controlling the tower top temperature.

[0041] It can be understood that the bottom of the temporary liquid storage tank 10 is connected with the return pipeline 13 and the low-boiling substance output pipeline 14 through the parallel connection of the third transmission pump 11 and the fourth transmission pump 12.

[0042] It can be understood that the temporary liquid storage tank 10 is provided with a liquid level transmitter, and the output end of the liquid level transmitter is electrically connected with the control end of the third transmission pump 11 and the fourth transmission pump 12.

[0043] The bottom of the uniform buffer tank 4 is connected to the rectifying tower 7 through the first transmission pump 5 and the second transmission pump 6 arranged in parallel.

[0044] The bottom of the rectifying tower 7 is connected to the reboiler 15 through the fifth transmission pump 16 and the sixth transmission pump 17 arranged in parallel.

[0045] The arrangement of one standby for each transmission pump can better cope with the emergency in the production process. When one transmission pump fails, the other can also realize the normal production process.

[0046] When the liquid level in the temporary liquid storage tank 10 reaches the set liquid level, the third transmission pump 11 or the fourth transmission pump 12 is started to output outward, and the discharged liquid is detected through the detection pipeline 18. When it does not meet the standard, the liquid is transported to the rectifying tower 7 through the return pipeline 13 for reseparation through the switching of the valve, and when it meets the standard, it is directly output through the low-boiling output pipeline 14.

[0047] The rectifying tower 7 is connected to the ammonia pipeline 19.

[0048] The addition of ammonia water in the rectification process can prevent self-polymerization and corrosion caused by a small amount of HCl in the kettle bottom liquid during removal.

[0049] Working principle:

[0050] The kettle bottom liquid of the 1,1-dichloroethylene production kettle is transported to the rectifying column 7 through the first transmission pump 5 or the parallel second transmission pump 6 through the kettle bottom liquid pipeline 1, high-boiling substances such as trichloroethane, tetrachloroethane, trichloroethylene, 1,2-dichloroethylene, a small amount of 1,1-dichloroethylene and the like are left at the bottom of the rectifying column 7, the low-boiling substance 1,1-dichloroethylene is evaporated from the top of the column, is condensed through the condenser 8, is controlled by the reflux ratio controller 9, part of which enters the temporary liquid storage tank 10, and part of which returns to the rectifying column 7 for further rectification and purification, when the liquid level in the temporary liquid storage tank 10 reaches the set liquid level, the third transmission pump 11 or the fourth transmission pump 12 is started to output outwardly, the discharged liquid is detected through the detection pipeline 18, when it does not meet the standard, the liquid is transported to the rectifying column 7 through the return pipeline 13 for re-separation through the switching of the valve, when it meets the standard, it is directly output through the low-boiling substance output pipeline 14. The high-boiling substance at the bottom of the rectifying column 7 is circulated through the reboiler 15 through the fifth transmission pump 16 or the sixth transmission pump 17 into the bottom of the rectifying column 7 until it is qualified and is output through the high-boiling substance output pipeline 20. In the rectification process, ammonia water is introduced to prevent self-polymerization and corrosion caused by a small amount of HCl in the kettle bottom liquid during removal. The low-boiling substance evaporated from the top of the rectifying column 7 is introduced into the jacket of the heat exchanger 3 and the uniform buffer tank 4 to heat the kettle bottom liquid before entering the rectifying column 7. First, the kettle bottom liquid is heated for the first time through the heat exchanger 3, but at this time, the kettle bottom liquid heated through the heat exchanger 3 is unstable and uneven in temperature. In order to solve the problem that the temperature in the rectifying column 7 is difficult to control, it is necessary to accurately control the uniform and stable temperature of the feed. Therefore, the kettle bottom liquid is introduced into the uniform buffer tank 4 for re-heating, stirring and homogenization, and then the uniform and stable liquid is pumped into the rectifying column 7 for treatment. The column overhead is condensed into liquid through the condenser 8 after heat exchange, thereby saving energy.

[0051] Each of the embodiments in the specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other. Each embodiment focuses on the difference from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiment.

[0052] The above only describes the embodiments of the present application and is not used to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A purification and recovery apparatus for a kettle bottom liquid of 1,1-dichloroethylene production, characterized by, The device comprises a kettle bottom liquid pipeline (1), the kettle bottom liquid pipeline (1) is connected with a heat exchanger (3) through a filter (2), the heat exchanger (3) is connected with a rectifying tower (7) through a uniform buffer tank (4), the rectifying tower (7) is provided with a reboiler (15) at the bottom, the rectifying tower (7) is connected with a temporary liquid storage tank (10) through a condenser (8) at the top, the temporary liquid storage tank (10) is connected with the rectifying tower (7) through a return pipeline (13), is connected with the next section through a low-boiling output pipeline (14), the rectifying tower (7) is connected with the jacket gas inlet of the heat exchanger (3) and the uniform buffer tank (4) through a pipeline at the top, the jacket gas outlet of the heat exchanger (3) and the uniform buffer tank (4) is connected with the condenser (8) through a pipeline, the rectifying tower (7) is provided with a tower top temperature transmitter at the top, and the rectifying tower (7) is provided with a high-boiling output pipeline (20) at the bottom.

2. The purification recovery apparatus for the bottom liquid of a 1,1-dichloroethylene production kettle according to claim 1, characterized by, The low-boiling output pipeline (14) is provided with a detection pipeline (18).

3. The purification and recovery apparatus for the bottom liquid of a 1,1-dichloroethylene production kettle according to claim 1, characterized by, The condenser (8) and the temporary liquid storage tank (10) are provided with a reflux ratio controller (9) therebetween, the reflux pipeline (901) of the reflux ratio controller (9) is connected with the rectifying tower (7) top inlet, and the production pipeline (902) of the reflux ratio controller (9) is connected with the temporary liquid storage tank (10).

4. The purification and recovery apparatus for the bottom liquid of a 1,1-dichloroethylene production kettle according to claim 3, characterized by, The output end of the tower top temperature transmitter is electrically connected with the control end of the reflux ratio controller (9).

5. The purification and recovery apparatus for the bottom liquid of a 1,1-dichloroethylene production kettle according to claim 2, characterized by, The bottom of the temporary liquid storage tank (10) is connected with the return pipeline (13) and the low-boiling output pipeline (14) through the parallelly arranged third transmission pump (11) and the fourth transmission pump (12).

6. The purification and recovery apparatus for the bottom liquid of a 1,1-dichloroethylene production kettle according to claim 5, characterized by The temporary liquid storage tank (10) is provided with a liquid level transmitter, and the output end of the liquid level transmitter is electrically connected with the control end of the third transmission pump (11) and the fourth transmission pump (12).

7. The purification and recovery apparatus for the bottom liquid of a 1,1-dichloroethylene production kettle according to claim 1, characterized by, The rectifying tower (7) is connected with an ammonia pipeline (19).

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