A vinyl chloride conversion system

Abstract

The application discloses a vinyl chloride conversion system, which comprises a raw material mixed gas storage, a hot water main pipe and a low-pressure steam main pipe, the raw material mixed gas storage is connected with a first gas inlet of a front converter through a gas inlet pipe, a first gas outlet of the front converter is connected with a first gas inlet of a rear converter through a gas outlet pipe, and the first gas outlet of the rear converter is connected with a mercury remover through a gas exhaust pipe; an injector is connected with a first inlet of a first gasification tank and a first inlet of a second gasification tank through a total water supply pipe, a second gas outlet of the front converter and a second gas outlet of the rear converter are connected with a second inlet of the first gasification tank and a second inlet of the second gasification tank through a first gas return pipe respectively. The conversion system solves the problem that the temperature of hot water in a heat circulation pipe of an existing conversion system often cannot reach the reaction requirement, and the reaction in the converter is often incomplete, thereby affecting the conversion rate.

Description

Technical Field

[0001] This application relates to the field of vinyl chloride reaction equipment technology, and in particular to a vinyl chloride conversion system. Background Technology

[0002] Polyvinyl chloride (PVC) is mainly used to manufacture PVC homopolymers and copolymers. It can also be copolymerized with vinyl acetate, butadiene, etc., and is used as an extractant for dyes and fragrances. It serves as a comonomer for many polymers, is an important raw material in the plastics industry, and can also be used as a refrigerant. Currently, vinyl chloride is mainly produced by the reaction of acetylene and hydrogen chloride in a converter, which is equipped with a low-mercury catalyst. During the reaction, a mixture of acetylene and hydrogen chloride enters the front-end converter at a certain temperature, where it reacts to produce vinyl chloride under the action of the catalyst. The reaction temperature inside the converter typically needs to be between 110-160 degrees Celsius. In existing conversion systems, the hot water in the heat circulation pipe needs to heat the converter. However, the hot water loses heat before flowing into the converter and cannot be reheated, often failing to reach the required temperature for the reaction. This frequently leads to incomplete reactions within the converter, affecting the conversion rate.

[0003] Therefore, this application provides a vinyl chloride conversion system to solve the above problems. Summary of the Invention

[0004] This application provides a vinyl chloride conversion system that solves the problem in existing conversion systems where hot water in the heat circulation pipe needs to heat the converter, but after heat loss before flowing into the converter, the hot water cannot be reheated, and the temperature often fails to meet the reaction requirements, frequently resulting in incomplete reaction in the converter and affecting the conversion rate.

[0005] To solve the above-mentioned technical problems, this application provides a vinyl chloride conversion system, including: a raw material mixed gas storage tank, a hot water main pipe and a low-pressure steam main pipe, wherein the raw material mixed gas storage tank is connected to the first air inlet of the pre-converter through an air inlet pipe, the first air outlet of the pre-converter is connected to the first air inlet of the post-converter through an air outlet pipe, and the first air outlet of the post-converter is connected to a mercury remover through an exhaust pipe.

[0006] The hot water main pipe is connected to the ejector via a main water inlet pipe, and the low-pressure steam main pipe is connected to the ejector via a steam inlet pipe. The ejector is connected to the first inlet of the first gasification tank and the first inlet of the second gasification tank via a main water supply pipe. The gas supply pipes connected to the first outlet of the first gasification tank and the first outlet of the second gasification tank are connected to the second inlet of the pre-converter and the second inlet of the post-converter, respectively. The second outlet of the pre-converter and the second outlet of the post-converter are connected to the second inlet of the first gasification tank and the second inlet of the second gasification tank, respectively, via a first return gas pipe. The tops of the first gasification tank and the second gasification tank are connected to the low-pressure steam main pipe via recovery pipes. The gas supply pipe is also connected to a return pipe, which is connected to a return water tank.

[0007] As a further embodiment, the pre-converter includes an upper tube box, a tube body, and a lower tube box. The upper tube box and the lower tube box are both connected to the tube body through support rings. Heat exchange tubes are installed inside the tube body through baffles.

[0008] As a further embodiment, the outer wall of the tube is provided with lug supports, which are located at both ends of the tube.

[0009] As a further embodiment, the number of second air inlets of the front converter and the number of second air inlets of the rear converter are both multiple and arranged in parallel.

[0010] As a further embodiment, the number of second air outlets of the front converter and the number of second air outlets of the rear converter are both multiple and arranged in parallel.

[0011] As a further embodiment, the main water inlet pipe is equipped with a first water supply pipe and a second water supply pipe connected in parallel. A first hot water pump is installed on the first water supply pipe, and a second hot water pump is installed on the second water supply pipe.

[0012] As a further embodiment, the ejector includes a housing body, with a hot water inlet at the bottom and a hot water outlet at the top. A steam heating pipe is installed vertically inside the housing body and is connected to the steam inlet pipe.

[0013] As a further embodiment, a first control valve assembly is installed on the intake pipe, the first control valve assembly including a switching valve, a check valve, a first pressure gauge, a first temperature sensor, a flow meter, and a first regulating valve; a second control valve assembly is installed on the recovery pipe, the second control valve assembly including a second pressure gauge, a second regulating valve, and a safety valve.

[0014] As a further embodiment, the raw material mixture storage tank is equipped with a preheater for heating.

[0015] As a further option, a third control valve assembly is installed on the main water supply pipe, the third control valve assembly including a third regulating valve and a second temperature sensor.

[0016] Compared to existing technologies, in the conversion system provided in this application, the mixed gas of hydrogen chloride and acetylene first enters the pre-converter through the inlet pipe. After undergoing an initial catalytic heating reaction in the pre-converter, it enters the post-converter for a complete reaction. The gas that has undergone complete reaction in the post-converter then enters the mercury remover for mercury removal. Meanwhile, the hot water in the hot water main enters the ejector and is reheated by steam supplied from the low-pressure steam main. The heated hot water then enters both the pre-converter and the post-converter to increase the reaction temperature.

[0017] Therefore, this conversion system has at least the following beneficial effects:

[0018] 1. This conversion system can reheat the hot water in the conversion system, so that the reaction temperature in the two converters can always be maintained at a high catalytic temperature, thus making the reaction process in the converter more thorough and the conversion rate higher;

[0019] 2. This conversion system can recover waste heat during the reaction process, saving energy and avoiding the waste of thermal energy. Attached Figure Description

[0020] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0021] Figure 1 This is a schematic diagram of the conversion system structure provided in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the pre-converter structure provided in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the injector structure provided in an embodiment of the present invention;

[0024] Figure 4 This is a top view of the front converter provided in an embodiment of the present invention.

[0025] In the diagram: 1. Raw material mixed gas storage tank; 2. Hot water main pipe; 3. Low-pressure steam main pipe; 10. Inlet pipe; 4. Pre-converter; 41. Outlet pipe; 5. Post-converter; 51. Exhaust pipe; 6. Mercury remover; 21. Main water inlet pipe; 31. Steam inlet pipe; 7. Ejector; 71. Main water supply pipe; 8. First gasification tank; 9. Second gasification tank; 91. Gas supply pipe; 451. First return gas pipe; 95. Recovery pipe; 92. Return pipe; 93. Return water tank; 42. Upper pipe box; 43. Pipe body; 44. Lower pipe box; 441. Support ring; 45. Baffle plate; 431. Ear-type support; 211. 1. Water supply pipe; 212. Second water supply pipe; 201. First hot water pump; 202. Second hot water pump; 46. Heat exchange pipe; 101. Air inlet pipe; 7101. Third regulating valve; 7102. Second temperature sensor; 111. Preheater; 701. Tank body; 702. Hot water inlet; 703. Hot water outlet; 704. Steam heating pipe; Switch valve 1011; Check valve 1012; First pressure gauge 1013; 1014. First temperature sensor; 1015. Flow meter; 1016. First regulating valve; 911. Second pressure gauge; 912. Second regulating valve; 913. Safety valve. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0028] The core of this application is to provide a vinyl chloride conversion system that can improve reaction efficiency and save reaction heat energy.

[0029] Figure 1This is a schematic diagram of the conversion system structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the pre-converter structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the injector structure provided in an embodiment of the present invention; Figure 4 This is a top view of the front converter provided in an embodiment of the present invention.

[0030] like Figure 1-3 As shown, the vinyl chloride conversion system provided in this application is mainly used for the catalytic conversion of vinyl chloride, a product of a mixture of hydrogen chloride and acetylene feedstocks. The feedstock mixture storage tank 1 stores the hydrogen chloride and acetylene reactants. To preheat the feedstock mixture storage tank 1 and increase the feed temperature of the reactants, a preheater 111 is installed on the feedstock mixture storage tank 1 as a further step. The preheater 111 is a common device for heating the feedstock mixture storage tank 1 and will not be described in detail here. The mixed gas in the feedstock mixture storage tank 1 first enters the pre-converter 4 through the first inlet of the pre-converter 4 via the inlet pipe 101. In the pre-converter 4, it is heated and reacts. The reacted mixed gas then enters the post-converter 5 through the outlet pipe 41 connected to the first outlet of the pre-converter 4. In the post-converter 5, the reaction can be carried out again. The vinyl chloride gas after the reheated reaction is discharged through the exhaust pipe 51 into the mercury remover 6 for mercury removal treatment. The treated vinyl chloride can be collected. After the low-pressure steam main 3 is connected to the ejector 7 via the steam inlet pipe 31, the steam in the low-pressure steam main 3 enters and reheats the temperature inside the ejector 7. For example... Figure 3 As shown, as a further embodiment, the ejector 7 includes a housing 701. A hot water inlet 702 is located at the bottom of the housing 701, and a hot water outlet 703 is located at the top of the housing 701. A steam heating pipe 704 is vertically installed inside the housing 701 and is connected to a steam inlet pipe 31. Specifically, after hot water enters the ejector 7 through the hot water inlet 702, steam enters the steam heating pipe 704 through the steam inlet pipe 31 to heat the hot water inside the ejector 7. During the heating process, the heating temperature can be monitored in real time by a temperature monitoring device, and the amount of steam entering the steam inlet pipe 31 can be controlled by valves or other control methods to meet different heating temperature requirements. The heated steam is discharged from the outlet of the steam heating pipe 704. To facilitate control of the hot water supply;

[0031] In this embodiment, after the hot water main pipe 2 is connected to the hot water supply equipment, the heating temperature in the hot water supply equipment is often constant, and the heating process of the hot water supply equipment often shares hot water with other existing equipment to be heated. Therefore, it is impossible to continuously adjust the supply temperature of the hot water. In this application, the hot water flows into the main water supply pipe 71 through the hot water main pipe 2 and then enters the ejector 7. The hot water entering the ejector 7 is reheated, and the heating process can be controlled.

[0032] In this embodiment, the gas mixture is automatically controlled during the intake process. As a further embodiment, a first control valve group is installed on the intake pipe 101, including a switching valve 1011, a check valve 1012, a first pressure gauge 1013, a first temperature sensor 1014, a flow meter 1015, and a first regulating valve 1016. A second control valve group is installed on the recovery pipe 95, including a second pressure gauge 911, a second regulating valve 912, and a safety valve 913. As a further embodiment, a first water supply pipe 211 and a second water supply pipe 212 are connected in parallel on the main water inlet pipe 21. A first hot water pump 201 is installed on the first water supply pipe 211, and a second hot water pump 202 is installed on the second water supply pipe 212. The first hot water pump 201 is a high-flow-rate hot water pump, which starts when the hot water supply is large. The second hot water pump 202 is a low-flow-rate hot water pump, which starts when the hot water supply is small. (The hot water supply is adjusted according to the reaction rate of the gas mixture). Therefore, the arrangement of the first water supply pipe 211 and the second water supply pipe 212 makes the hot water supply more efficient. The hot water heated in the ejector 7 enters the first vaporization tank 8 and the second vaporization tank 9 from the main water supply pipe 71 for vaporization. The vaporized hot water then enters the heating layers of the pre-converter 4 and the post-converter 5 from the gas supply pipe 91 to heat the gas within them. Figure 2 As shown, as a further embodiment, the pre-converter 4 includes an upper tube box 42, a tube body 43, and a lower tube box 44. Both the upper tube box 42 and the lower tube box 44 are connected to the tube body 43 via support rings 441. Heat exchange tubes 46 are installed inside the tube body 43 via baffles 45. It should be noted that the pre-converter 4 has the same structure as the post-converter 5. The support rings 441 on the pre-converter 4 serve as a connecting mechanism, allowing the upper tube box 42 and the lower tube box 44 to be connected to the tube body 43 respectively. The vaporized gas enters the heat exchange tubes 46, which are arranged in a circulating manner on the inner wall of the pre-converter 4 via baffles 45. As a further embodiment, lug supports 431 are also provided on the outer wall of the tube body 43, located at both ends of the tube body 43. The lug supports 431 facilitate hoisting.

[0033] In this embodiment, as Figure 4As shown, to ensure that the heating gas enters the converters (front converter 4 and rear converter 5) evenly, as a further design, both the front converter 4 and the rear converter 5 have multiple second air inlets arranged in parallel. Therefore, the heating gas can enter the converters simultaneously for heating. To ensure that the heating gas exits the converters (front converter 4 and rear converter 5) evenly, as a further design, both the front converter 4 and the rear converter 5 have multiple second air outlets arranged in parallel.

[0034] In this embodiment, the steam generated from the catalytic reaction of the gases in the pre-converter 4 and post-converter 5 re-enters the first gasification tank 8 and the second gasification tank 9 through the first return gas pipe 451, respectively. The steam then exits through the recovery pipe 95 and enters the low-pressure steam main pipe 3 for further recovery. The recovered gas can be reused as a heating gas source.

[0035] In this embodiment, to facilitate the control of the water supply volume of the main water supply pipe 71 and the monitoring of the water supply temperature, as a further solution, a third control valve group is installed on the main water supply pipe 71. The third control valve group includes a third regulating valve 7101 and a second temperature sensor 7102. The steam inlet pipe 31 is equipped with a conventional regulating valve that can adjust the intake air volume.

[0036] Compared to existing technologies, the vinyl chloride conversion system provided in this application includes: a raw material mixed gas storage tank 1, a hot water main pipe 2, and a low-pressure steam main pipe 3. The raw material mixed gas storage tank 1 is connected to the first inlet of the pre-converter 4 via an inlet pipe 101. The first outlet of the pre-converter 4 is connected to the first inlet of the post-converter 5 via an outlet pipe 41. The first outlet of the post-converter 5 is connected to a mercury remover 6 via an exhaust pipe 51. The hot water main pipe 2 is connected to an ejector 7 via a main water inlet pipe 21, and the low-pressure steam main pipe 3 is connected to an ejector 7 via a steam inlet pipe 31. The ejector 7 is connected to the first inlet of the first gasification tank 8 and the first inlet of the first gasification tank 8 via a main water supply pipe 71. The first inlet of the second gasification tank 9 is connected to the first outlet of the first gasification tank 8 and the first outlet of the second gasification tank 9. The gas supply pipes 91 connected to them are respectively connected to the second inlet of the front converter 4 and the second inlet of the rear converter 5. The second outlet of the front converter 4 and the second outlet of the rear converter 5 are respectively connected to the second inlet of the first gasification tank 8 and the second inlet of the second gasification tank 9 through the first return gas pipe 451. The tops of the first gasification tank 8 and the second gasification tank 9 are respectively connected to the low-pressure steam main pipe 3 through the recovery pipe 95. The gas supply pipe 91 is also connected to the return pipe 92, which is connected to the return water tank 93.

[0037] The proposed conversion system can reheat the hot water in the conversion system, so that the reaction temperature in the two converters can always be maintained at a high catalytic temperature, thus making the reaction process in the converter more thorough and the conversion rate higher. The conversion system can also recover the waste heat in the reaction process, saving energy and avoiding the waste of thermal energy.

[0038] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and incorporate common knowledge or customary techniques in the art disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of this application is indicated by the claims.

[0040] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The embodiments of this application described above do not constitute a limitation on the scope of protection of this application.

Claims

1. A vinyl chloride conversion system, characterized in that, include: The raw material mixed gas storage tank, hot water main pipe and low-pressure steam main pipe are provided. The raw material mixed gas storage tank is connected to the first air inlet of the pre-converter through an air inlet pipe. The first air outlet of the pre-converter is connected to the first air inlet of the post-converter through an air outlet pipe. The first air outlet of the post-converter is connected to the mercury remover through an exhaust pipe. The hot water main pipe is connected to the ejector via a main water inlet pipe, and the low-pressure steam main pipe is connected to the ejector via a steam inlet pipe. The ejector is connected to the first inlet of the first gasification tank and the first inlet of the second gasification tank via a main water supply pipe. The gas supply pipes connected to the first outlet of the first gasification tank and the first outlet of the second gasification tank are connected to the second inlet of the pre-converter and the second inlet of the post-converter, respectively. The second outlet of the pre-converter and the second outlet of the post-converter are connected to the second inlet of the first gasification tank and the second inlet of the second gasification tank, respectively, via a first return gas pipe. The tops of the first gasification tank and the second gasification tank are connected to the low-pressure steam main pipe via recovery pipes. The gas supply pipe is also connected to a return pipe, which is connected to a return water tank.

2. The vinyl chloride conversion system according to claim 1, characterized in that, The pre-converter includes an upper tube box, a tube body, and a lower tube box. The upper tube box and the lower tube box are both connected to the tube body through support rings. Heat exchange tubes are installed in the tube body through baffles.

3. The vinyl chloride conversion system according to claim 2, characterized in that, The outer wall of the tube is also provided with ear-type supports, which are located at both ends of the tube.

4. The vinyl chloride conversion system according to claim 1, characterized in that, The number of second air inlets of the front converter and the number of second air inlets of the rear converter are both multiple and arranged in parallel.

5. The vinyl chloride conversion system according to claim 1, characterized in that, The number of second air outlets of the front converter and the number of second air outlets of the rear converter are both multiple and arranged in parallel.

6. The vinyl chloride conversion system according to claim 1, characterized in that, The main water inlet pipe is equipped with a first water supply pipe and a second water supply pipe connected in parallel. A first hot water pump is installed on the first water supply pipe, and a second hot water pump is installed on the second water supply pipe.

7. The vinyl chloride conversion system according to claim 1, characterized in that, The ejector includes a box body, a hot water inlet at the bottom of the box body, a hot water outlet at the top of the box body, and a steam heating pipe installed vertically inside the box body, the steam heating pipe being connected to the steam inlet pipe.

8. The vinyl chloride conversion system according to claim 1, characterized in that, The intake pipe is equipped with a first control valve assembly, which includes a switching valve, a check valve, a first pressure gauge, a first temperature sensor, a flow meter, and a first regulating valve; the recovery pipe is equipped with a second control valve assembly, which includes a second pressure gauge, a second regulating valve, and a safety valve.

9. A vinyl chloride conversion system according to claim 1, characterized in that, The raw material mixture storage tank is equipped with a preheater for heating.

10. A vinyl chloride conversion system according to claim 1, characterized in that, A third control valve assembly is installed on the main water supply pipe. The third control valve assembly includes a third regulating valve and a second temperature sensor.

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