Dichloroethane purification device and polyvinyl chloride production system

Abstract

The utility model provides a dichloroethane purification device and a polyvinyl chloride production system, and relates to the technical field of polyvinyl chloride production, the dichloroethane purification device comprises: a rectifying tower having a reboiler, a condenser and a gas phase outlet; the reboiler is provided with a material inlet and is connected with a hot water circulating pipeline; the high-boiling-point substance storage tank is provided with a high-boiling-point substance inlet and a high-boiling-point substance outlet; the high-boiling residue outlet is connected with the material inlet; the residual liquid storage tank is provided with a residual liquid inlet, and the residual liquid inlet is connected with the liquid phase outlet of the reboiler; wherein a high-boiling-point substance flow regulating valve is arranged on a pipeline between the high-boiling-point substance outlet and the material inlet; a temperature sensor is arranged on the reboiler, a temperature regulating valve is arranged on the hot water circulating pipeline, the temperature sensor and the temperature regulating valve are interlocked, and the temperature regulating valve can enable high-boiling residues in the reboiler to be heated at a constant speed. According to the device, vinyl chloride and dichloroethane can be completely decomposed from high-boiling residues, and the purity of recovered dichloroethane is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of polyvinyl chloride production, in particular to an ethylene dichloride purification device and a polyvinyl chloride production system. Background Art

[0002] In the conversion process of the polyvinyl chloride production process, hydrogen chloride gas and acetylene gas are heated and reacted with a mercury-containing catalyst to produce vinyl chloride. In the conversion process, the excessive reaction of hydrogen chloride is controlled to facilitate the removal of impurities from the product gas in the later stage. After the vinyl chloride is produced, due to the excess hydrogen chloride, a trace amount of by-product ethylene dichloride is produced in the secondary reaction of vinyl chloride under high temperature conditions, resulting in high-boiling substances containing ethylene dichloride and vinyl chloride.

[0003] The ethylene dichloride in the high-boiling product is mainly separated as a heavy component into the residual liquid storage tank in the distillation tower of the subsequent distillation process, and the vinyl chloride separated from the high-boiling product can enter the subsequent polyvinyl chloride production process. The current distillation tower processing system has been in use for 20 years, with a low degree of automation and manual operation by employees. In addition, the high-boiling product cannot be completely decomposed into vinyl chloride and ethylene dichloride during the heating process, resulting in a low purity of the recovered ethylene dichloride.

[0004] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or any form of implication that the information constitutes the prior art known to those skilled in the art. Utility Model Content

[0005] In view of the above situation, the utility model provides a dichloroethane purification device and a polyvinyl chloride production system, aiming to solve the technical problems that the existing distillation tower processing system has been in use for 20 years, has a low degree of automation, relies entirely on manual operation by employees, and high boiling points cannot be completely decomposed into vinyl chloride and dichloroethane during the heating process, resulting in low purity of the recovered dichloroethane.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] In a first aspect, the utility model provides a dichloroethane purification device, comprising:

[0008] The distillation tower has a reboiler, a condenser and a gas phase outlet; the reboiler has a material inlet; the reboiler is connected to a hot water circulation pipeline;

[0009] The high boiling material storage tank has a high boiling material inlet and a high boiling material outlet; the high boiling material outlet is connected to the material inlet;

[0010] A residual liquid storage tank having a residual liquid inlet connected to a liquid phase outlet of the reboiler;

[0011] in:

[0012] A high boiling material flow regulating valve is provided on the pipeline between the high boiling material outlet and the material inlet;

[0013] The reboiler is provided with a temperature sensor, the hot water circulation pipeline is provided with a temperature regulating valve, the temperature sensor and the temperature regulating valve are interlocked, and the temperature regulating valve can make the high boiling materials in the reboiler heat up at a uniform speed.

[0014] In some embodiments of the present invention, the temperature sensor and the temperature regulating valve are interlocked and controlled by a DCS system.

[0015] In some embodiments of the present invention, the high-boiler storage tank has a high-boiler storage tank vent.

[0016] In some embodiments of the present invention, the high boiling material storage tank has a high boiling material storage tank nitrogen inlet.

[0017] In some embodiments of the present invention, the residual liquid storage tank has a residual liquid storage tank drain port.

[0018] In some embodiments of the present invention, the residual liquid storage tank has a residual liquid storage tank nitrogen inlet.

[0019] In some embodiments of the present invention, the high boiling material storage tank is further provided with a pressure gauge.

[0020] In some embodiments of the present invention, the high boiling material storage tank is further provided with a liquid level meter.

[0021] In some embodiments of the present invention, the high boiling material storage tank is further provided with a storage tank temperature detector.

[0022] In a second aspect, the utility model provides a polyvinyl chloride production system, comprising the above-mentioned ethylene dichloride purification device.

[0023] The embodiments of the present invention have at least the following advantages or beneficial effects:

[0024] On the one hand, a high-boiling material flow regulating valve is arranged on the pipeline between the high-boiling material outlet and the material inlet of the reboiler. The high-boiling material flow regulating valve is connected to the DCS system to automatically adjust the high-boiling material flow entering the reboiler according to preset parameters, thereby realizing precise feeding; on the other hand, a temperature regulating valve is arranged on the hot water circulation pipeline. The temperature sensor and the temperature regulating valve are interlocked and controlled by the DCS system to make the high-boiling material in the reboiler heat up at a uniform rate, thereby achieving the complete decomposition of vinyl chloride and ethylene dichloride from the high-boiling material through the combined effect of the above two aspects and improving the purity of the recovered ethylene dichloride.

[0025] Other features and advantages of the present invention will be set forth in the following description, and in part will become apparent from the description, or may be understood by practicing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a schematic diagram of the structure of the ethylene dichloride purification device.

[0028] icon:

[0029] 1-distillation tower, 11-reboiler, 12-condenser, 13-gas phase outlet, 14-temperature sensor,

[0030] 2-high boiling material storage tank, 21-high boiling material inlet, 22-high boiling material outlet, 23-high boiling material storage tank venting port, 24-high boiling material storage tank nitrogen inlet, 25-high boiling material flow regulating valve,

[0031] 3-residual liquid storage tank, 31-residual liquid inlet, 32-residual liquid storage tank venting port, 33-residual liquid storage tank nitrogen inlet,

[0032] 4-hot water circulation pipe, 41-temperature regulating valve,

[0033] 51-pressure gauge, 52-liquid level gauge, 53-tank temperature detector. DETAILED DESCRIPTION

[0034] In the following, only some exemplary embodiments are briefly described. As those skilled in the art can appreciate, the described embodiments can be modified in various different ways without departing from the spirit or scope of the embodiments of the present invention.

[0035] In the description of the embodiments of the present invention, it should be understood that the term "plurality" means two or more than two, unless otherwise clearly and specifically defined.

[0036] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0037] The embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0038] See also Figure 1 This embodiment provides a polyvinyl chloride production system, including a dichloroethane purification device; the dichloroethane purification device is a part of the polyvinyl chloride production system, and this embodiment mainly improves the original distillation process in the system.

[0039] The ethylene dichloride purification device comprises a distillation tower 1, a high boiling point storage tank 2 and a residual liquid storage tank 3.

[0040] The distillation tower 1 has a reboiler 11 at the lower part, a condenser 12 at the upper part, and a gas phase outlet 13 at the top; wherein the reboiler 11 has a material inlet for introducing high boiling substances (including ethylene dichloride and vinyl chloride), and the reboiler 11 is connected to a hot water circulation pipeline 4 for heating the high boiling substances.

[0041] The reboiler 11 is provided with a temperature sensor 14, and the hot water circulation pipe 4 is provided with a temperature regulating valve 41. The temperature sensor 14 and the temperature regulating valve 41 are interlocked and controlled by the DCS system. The temperature regulating valve 41 adjusts the heating rate of the high-boiling substances in the reboiler 11 by adjusting the flow rate in the hot water circulation pipe 4, so that the high-boiling substances in the reboiler 11 are heated at a uniform rate, thereby achieving complete decomposition of vinyl chloride and ethylene dichloride and improving the purity of the recovered ethylene dichloride.

[0042] The high boiling material storage tank 2 has a high boiling material inlet 21 , a high boiling material outlet 22 , a high boiling material storage tank venting port 23 , and a high boiling material storage tank nitrogen inlet 24 .

[0043] The high-boiling material inlet 21 is connected to the conversion section, and the hydrogen chloride gas and the acetylene gas react in the conversion section to generate high-boiling materials as byproducts. The high-boiling materials enter the high-boiling material storage tank 2 from the high-boiling material inlet 21, and there may be multiple high-boiling material inlets 21.

[0044] The high boiling material outlet 22 is connected to the material inlet of the reboiler 11; a high boiling material flow regulating valve 25 is provided on the pipeline between the high boiling material outlet 22 and the material inlet of the reboiler 11; the high boiling material flow regulating valve 25 can be connected to the DCS system to automatically adjust the high boiling material flow entering the reboiler 11 according to preset parameters, thereby realizing precise feeding.

[0045] The high boiling material storage tank vent port 23 and the high boiling material storage tank nitrogen inlet port 24 are used as safety measures.

[0046] In combination with the above contents, in this embodiment, on the one hand, a high-boiling material flow regulating valve 25 is provided on the pipeline between the high-boiling material outlet 22 and the material inlet of the reboiler 11, and the high-boiling material flow regulating valve 25 is connected to the DCS system to automatically adjust the high-boiling material flow entering the reboiler 11 according to preset parameters, thereby realizing accurate feeding; on the other hand, a temperature regulating valve 41 is provided on the hot water circulation pipeline 4, and the temperature sensor 14 and the temperature regulating valve 41 are interlocked and controlled by the DCS system to make the high-boiling material in the reboiler 11 heat up at a uniform speed, so that through the combined effect of the above two aspects, vinyl chloride and ethylene dichloride are completely (as completely as possible) decomposed from the high-boiling material, and the purity of the recovered ethylene dichloride is improved.

[0047] The residual liquid storage tank 3 has a residual liquid inlet 31 , a residual liquid storage tank drain port 32 , and a residual liquid storage tank nitrogen inlet 33 .

[0048] The residual liquid inlet 31 is connected to the liquid phase outlet of the reboiler 11 and is used to introduce the residual liquid in the bottom of the distillation tower 1 into the residual liquid storage tank 3 for collection.

[0049] The residual liquid storage tank vent port 32 and the residual liquid storage tank nitrogen inlet port 33 are used as safety measures.

[0050] The high boiling material storage tank 2 and / or the residual liquid storage tank 3 are also provided with a pressure gauge 51, a liquid level gauge 52 and / or a storage tank temperature detector 53 for monitoring the pressure, liquid level and / or temperature inside the high boiling material storage tank 2 and / or the residual liquid storage tank 3.

[0051] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. In the absence of conflicts, the embodiments of the present application and the features in the embodiments may be combined with each other at will. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dichloroethane purification device, characterized in that: include: a distillation column having a reboiler, a condenser and a vapor phase outlet; The reboiler has a material inlet; The reboiler is connected with a hot water circulation pipeline; A high-boiling material storage tank having a high-boiling material inlet and a high-boiling material outlet; the high-boiling material outlet is connected to the material inlet; A residual liquid storage tank having a residual liquid inlet, wherein the residual liquid inlet is connected to the liquid phase outlet of the reboiler; in: A high boiling material flow regulating valve is provided on the pipeline between the high boiling material outlet and the material inlet; The reboiler is provided with a temperature sensor, the hot water circulation pipeline is provided with a temperature regulating valve, the temperature sensor and the temperature regulating valve are interlocked, and the temperature regulating valve can increase the temperature of the high-boiling substances in the reboiler at a uniform rate.

2. The ethylene dichloride purification device according to claim 1, characterized in that: The temperature sensor and the temperature regulating valve are interlocked and controlled by a DCS system.

3. The ethylene dichloride purification device according to claim 1, characterized in that: The high-boiling-material storage tank has a high-boiling-material storage tank vent.

4. The ethylene dichloride purification device according to claim 1, characterized in that: The high boiling material storage tank has a high boiling material storage tank nitrogen inlet.

5. The ethylene dichloride purification device according to claim 1, characterized in that: The residual liquid storage tank has a residual liquid storage tank discharge port.

6. The ethylene dichloride purification device according to claim 1, characterized in that: The residual liquid storage tank has a residual liquid storage tank nitrogen inlet.

7. The ethylene dichloride purification device according to claim 1, characterized in that: The high boiling material storage tank is also provided with a pressure gauge.

8. The ethylene dichloride purification device according to claim 1, characterized in that: The high boiling material storage tank is also provided with a liquid level meter.

9. The ethylene dichloride purification device according to claim 1, characterized in that: The high boiling material storage tank is also provided with a storage tank temperature detector.

10. A polyvinyl chloride production system, characterized in that: It comprises the ethylene dichloride purification device as described in any one of claims 1 to 9.

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