Vinyl chloride synthesis process system with high practicability

Abstract

The utility model relates to a vinyl chloride synthesis process system with high practicability. The vinyl chloride synthesis process system comprises a converter (1), a gas inlet pipe (2), a gas outlet pipe (3), a gas inlet branch pipe (21), a gas outlet branch pipe (31) and four tangential valves, the two ends of the air inlet branch pipe (21) are respectively communicated with the air inlet pipe (2) and the tube pass upper port (12), the pipe section on the downstream side of the air inlet pipe (2) is used as an air inlet main pipe (20), the two ends of the air outlet branch pipe (31) are respectively communicated with the air outlet pipe (3) and the tube pass lower port (11), the pipe section on the upstream side of the air outlet pipe (3) is used as an air outlet main pipe (30), and the four tangential valves are respectively used for controlling the on-off of the air inlet main pipe (20), the air inlet branch pipe (21), the air outlet main pipe (30) and the air outlet branch pipe (31). The utility model can solve the problems that the catalyst utilization rate of the existing converter is low, the catalyst needs to be turned over by manpower and time, the production cycle is prolonged, and the production cost is increased.

Description

Technical Field

[0001] The utility model relates to vinyl chloride production equipment, in particular to a process for a conversion system for preparing vinyl chloride by a synthetic method. Background Art

[0002] The acetylene method is the most important chemical synthesis method for producing vinyl chloride, that is, vinyl chloride is generated by a synthesis reaction of acetylene gas and hydrogen chloride gas under the action of a catalyst. The catalytic synthesis of acetylene and hydrogen chloride is an exothermic reaction. To ensure that the reaction zone can maintain an appropriate temperature, a shell-and-tube heat exchanger installed vertically is selected as the converter.

[0003] The existing process for producing vinyl chloride using a converter can be seen in Figure 4 , a catalyst is filled in the tube-side heat exchange tubes of the converter 01. A mixed gas of acetylene and hydrogen chloride enters from the lower port 011 of the tube side of the converter 01, reacts to generate vinyl chloride after contacting the catalyst in the heat exchange tubes, and then exits from the upper port 012 of the tube side. At the same time, a refrigerant enters the channel outside the heat exchange tubes from the shell-side inlet 013 and then flows out from the shell-side outlet 014 to cool the heat exchange tubes.

[0004] However, since the mixed gas always enters from the lower end of the converter and always contacts the catalyst located in the lower part first, the catalyst in the lower part is prone to aging and a decrease in activity, the main reaction zone moves upward, and the contact time and opportunity between the mixed gas and the catalyst become less, resulting in an incomplete synthesis reaction. Therefore, in the existing process during production, it is necessary to frequently stop the machine and manually turn the unaged catalyst in the upper part downward so that the catalyst can be fully utilized. This not only takes time and effort but also prolongs the production cycle and increases the production cost. Summary of the Utility Model

[0005] The purpose of the utility model is to solve the problems in the process of producing vinyl chloride by the synthetic method, such as low catalyst utilization rate caused by the aging of the catalyst in the lower part of the tube side of the converter, the need to spend manpower and time turning the catalyst, prolonging the production cycle, and increasing the production cost.

[0006] For the above purpose, the utility model provides a vinyl chloride synthesis process system with strong practicability, including a converter 1, the converter 1 having tube-side heat exchange tubes and a shell-side channel, a catalyst can be filled in the tube-side heat exchange tubes, and a flowing refrigerant can be filled in the shell-side channel.

[0007] It further includes an inlet pipe 2, an outlet pipe 3, an inlet branch pipe 21, an outlet branch pipe 31, an inlet main tangential valve 211, an inlet auxiliary tangential valve 212, an outlet main tangential valve 311, and an outlet auxiliary tangential valve 312.

[0008] The inlet pipe 2 is communicated with the lower port 11 of the tube side of the converter 1 to input a mixed gas of acetylene and hydrogen chloride into the tube-side heat exchange tubes of the converter 1.

[0009] The outlet pipe 3 is connected to the upper port 12 of the tube side of the converter 1, and vinyl chloride gas is output from the tube side of the converter 1.

[0010] The first end of the intake branch pipe 21 is connected to the intake pipe 2, the second end is connected to the upper port 12 of the tube side, and the intake sub-tangential valve 212 is used to control the on-off of the intake branch pipe 21.

[0011] The pipe section of the intake pipe 2 located on the downstream side of the first end of the intake branch pipe 21 serves as the intake main pipe 20, and the intake main tangential valve 211 is used to control the on-off of the intake main pipe 20.

[0012] The first end of the outlet branch pipe 31 is connected to the outlet pipe 3, the second end is connected to the lower port 11 of the tube side, and the outlet sub-tangential valve 312 is used to control the on-off of the outlet branch pipe 31.

[0013] The pipe section of the outlet pipe 3 located on the upstream side of the first end of the outlet branch pipe 31 serves as the outlet main pipe 30, and the outlet main tangential valve 311 is used to control the on-off of the outlet main pipe 30.

[0014] Therefore, after the catalyst is used for a period of time, the flow direction of the gas phase in the converter is switched by using the intake main tangential valve 211, the intake sub-tangential valve 212, the outlet main tangential valve 311, and the outlet sub-tangential valve 312, so that the mixed gas moves downward in the heat exchange tubes of the tube side and contacts the un-aged catalyst in the upper part. In this way, the catalyst with higher activity in the converter can be fully utilized. It can not only improve the utilization rate of the catalyst and make full use of the catalyst activity, but also does not require the operation of turning over the catalyst, greatly saving the catalyst replacement time and replacement cost, and can also reduce the harm caused by the catalyst to the human body.

[0015] Preferably, a vinyl chloride synthesis process system with strong practicability further includes a refrigerant inlet pipe 41 and a refrigerant outlet pipe 42. The shell side inlet 401 of the converter 1 is located below the shell side outlet 402. The refrigerant inlet pipe 41 is connected to the shell side inlet 401, and the refrigerant outlet pipe 42 is connected to the shell side outlet 402. The refrigerant enters through the refrigerant inlet pipe 41, fills the shell side, and then exits through the refrigerant outlet pipe 42.

[0016] Preferably, a vinyl chloride synthesis process system with strong practicability is also provided with an intake boundary valve 201, an outlet boundary valve 301, an activation branch pipe 202, and an activation valve 2021.

[0017] The intake boundary valve 201 is arranged in the intake pipe 2 and is located on the upstream side of the first end of the intake branch pipe 21. The outlet boundary valve 301 is arranged in the outlet pipe 3 and is located on the downstream side of the first end of the outlet branch pipe 31.

[0018] The first end of the activation branch pipe 202 is connected to the intake pipe 2, located between the intake boundary valve 201 and the first end of the outlet branch pipe 31. The second end of the activation branch pipe 202 is connected to a dry hydrogen chloride gas source. An activation valve 2021 is provided in the activation branch pipe 202 to control the on-off of the activation branch pipe 202.

[0019] Therefore, by using the activation branch pipe 202 and the activation valve 2021, dry hydrogen chloride gas can be quantitatively introduced into the tube-side heat exchange tubes of the converter 1, enabling the fresh catalyst to reach the activation state, which is beneficial to improving the synthesis reaction efficiency.

[0020] Preferably, the vinyl chloride synthesis process system further includes an intake gas flowmeter 203. The intake gas flowmeter 203 is provided in the intake pipe 2, downstream of the connection between the intake pipe 2 and the first end of the activation branch pipe 202 and upstream of the connection between the intake pipe 2 and the first end of the intake branch pipe 21, for measuring the intake gas flow.

[0021] Preferably, a vinyl chloride synthesis process system with strong practicability further includes an intake gas flow regulating valve 302. The intake gas flow regulating valve 302 is provided between the first end of the outlet branch pipe 31 and the outlet boundary valve 301. By adjusting the opening degree of the intake gas flow regulating valve 302, the intake gas flow can be adjusted.

[0022] Preferably, the intake gas flowmeter 203 and the intake gas flow regulating valve 302 are in cascade control, which is convenient for quantitative control of the reaction, and thus is beneficial to controlling and improving the conversion rate of acetylene.

[0023] Preferably, a vinyl chloride synthesis process system with strong practicability further includes an intake gas thermometer 204. The intake gas thermometer 204 is provided in the intake pipe 2, on the downstream side of the intake gas flowmeter 203, for measuring the temperature of the intake gas.

[0024] Preferably, a vinyl chloride synthesis process system with strong practicability further includes an intake gas pressure gauge 205. The intake gas pressure gauge 205 is provided in the intake pipe 2, on the downstream side of the intake gas flowmeter 203, for measuring the pressure of the intake gas.

[0025] Preferably, in a vinyl chloride synthesis process system with strong practicability, a thermocouple temperature sensor 101 for detecting the bed temperature is provided inside the converter 1 to measure the reaction temperature inside the converter 1.

[0026] The vinyl chloride synthesis process system provided by the present utility model is easy to operate, can solve the problems of low catalyst utilization rate, need to spend manpower and time to turn over the catalyst, extend the production cycle, and increase production costs caused by catalyst aging in the lower part of the tube side of the converter in the vinyl chloride production process by synthesis method, has strong practicability, and is suitable for popularization. Description of the Drawings

[0027] Figure 1 It is an explanatory diagram of the process structure of a highly practical vinyl chloride synthesis process system;

[0028] Figure 2 It is an explanatory diagram of the process when a highly practical vinyl chloride synthesis process system uses fresh catalyst for production;

[0029] Figure 3 It is an explanatory diagram of the process when a highly practical vinyl chloride synthesis process system uses the catalyst aged at the lower part for production;

[0030] Figure 4 It is an explanatory diagram of the process flow for producing vinyl chloride using a converter.

[0031] Reference numerals:

[0032] Figures 1 - 3 : 1 - Converter; 11 - Lower port of the tube side; 12 - Upper port of the tube side; 101 - Thermocouple temperature sensor; 2 - Inlet pipe; 20 - Main inlet pipe; 21 - Inlet branch pipe; 211 - Main tangential valve for inlet; 212 - Auxiliary tangential valve for inlet; 201 - Inlet boundary valve; 301 - Outlet boundary valve; 202 - Activation branch pipe; 2021 - Activation valve; 203 - Inlet flowmeter; 302 - Inlet flow regulating valve; 204 - Inlet thermometer; 205 - Inlet pressure gauge; 3 - Outlet pipe; 30 - Main outlet pipe; 31 - Outlet branch pipe; 311 - Main tangential valve for outlet; 312 - Auxiliary tangential valve for outlet; 401 - Inlet of the shell side; 402 - Outlet of the shell side; 41 - Refrigerant inlet liquid pipe; 42 - Refrigerant outlet liquid pipe.

[0033] Figure 4 : 01 - Converter; 011 - Lower port of the tube side; 012 - Upper port of the tube side; 013 - Inlet of the shell side; 014 - Outlet of the shell side. Detailed implementation mode

[0034] The following elaborates on the embodiments of the present invention in conjunction with the attached drawings. The following description is a concretization of the claims of the present invention.

[0035] Embodiment

[0036] Figure 1 Shows the process of a highly practical vinyl chloride synthesis process system, Figure 2 、 3 Respectively show the process flow diagrams of the vinyl chloride synthesis process system when using fresh catalyst and the catalyst aged at the lower part.

[0037] Such as Figure 1As shown in the figure, the conversion system includes: a converter 1, an intake pipe 2, an exhaust pipe 3, an intake branch pipe 21, an exhaust branch pipe 31, an intake main tangential valve 211, an intake auxiliary tangential valve 212, an exhaust main tangential valve 311, and an exhaust auxiliary tangential valve 312.

[0038] The converter 1 is a vertically installed shell-and-tube heat exchanger with a tube-side heat exchange tube and a shell-side channel. The tube-side heat exchange tube serves as the site for the synthesis reaction and is filled with a catalyst inside, and a flowing coolant is installed in the shell-side channel for cooling to control the temperature of the converter bed.

[0039] Combined Figure 2 Looking at it, the intake pipe 2 is connected to the lower port 11 of the tube side of the converter 1 and is used to input the mixed gas of acetylene and hydrogen chloride into the tube-side heat exchange tube of the converter 1.

[0040] The exhaust pipe 3 is connected to the upper port 12 of the tube side of the converter 1 and is used to output vinyl chloride gas from the tube side of the converter 1.

[0041] Referring to the middle and lower part of Figure 1, the first end of the intake branch pipe 21 is connected to the intake pipe 2, the second end is connected to the upper port 12 of the tube side, and the intake auxiliary tangential valve 212 is arranged in the intake branch pipe 21 and is used to control the on-off of the intake branch pipe 21.

[0042] Referring to Figure 1 The lower part, the pipe section of the intake pipe 2 located on the downstream side of the first end of the intake branch pipe 21 serves as the intake main pipe 20, and the intake main tangential valve 211 is arranged in the intake main pipe 20 and is used to control the on-off of the intake main pipe 20.

[0043] Referring to Figure 1 The middle part, the first end of the exhaust branch pipe 31 is connected to the exhaust pipe 3, the second end is connected to the lower port 11 of the tube side, and the exhaust auxiliary tangential valve 312 is arranged in the exhaust branch pipe 31 and is used to control the on-off of the exhaust branch pipe 31.

[0044] Referring to Figure 1 The upper right part of Figure 1, the pipe section of the exhaust pipe 3 located on the upstream side of the first end of the exhaust branch pipe 31 serves as the exhaust main pipe 30, and the exhaust main tangential valve 311 is arranged in the exhaust main pipe 30 and is used to control the on-off of the exhaust main pipe 30.

[0045] By using the intake main tangential valve 211, the intake auxiliary tangential valve 212, the exhaust main tangential valve 311, and the exhaust auxiliary tangential valve 312, the flow directions of the mixed gas and the vinyl chloride gas can be controlled. For specific details, please refer to the description part about the beneficial effects of the present utility model at the end of the specification.

[0046] To ensure the normal and safe operation of the conversion system, the conversion system further includes a refrigerant inlet pipe 41, a refrigerant outlet pipe 42, an inlet boundary valve 201, an outlet boundary valve 301, an activation branch pipe 202, an activation valve 2021, an inlet flowmeter 203, an inlet flow regulating valve 302, an inlet thermometer 204, an inlet pressure gauge 205, and a thermocouple temperature sensor 101. The following provides a detailed description of the above structures.

[0047] See Figure 1 In the middle part, the shell-side inlet 401 of the converter 1 is located below the shell-side outlet 402. The refrigerant inlet pipe 41 is connected to the shell-side inlet 401, and the refrigerant outlet pipe 42 is connected to the shell-side outlet 402. The refrigerant enters through the refrigerant inlet pipe 41, fills the shell side, and then exits through the refrigerant outlet pipe 42. After being cooled in the cooling system (not shown in the figure), the refrigerant can be recycled.

[0048] See Figure 1 In the upper part, the inlet boundary valve 201 is arranged in the inlet pipe 2, upstream of the first end of the outlet branch pipe 31. The outlet boundary valve 301 is arranged in the outlet pipe 3, downstream of the first end of the outlet branch pipe 31. The inlet boundary valve 201 and the outlet boundary valve 301 are selected as globe valves. By only controlling their closing, the converter 1 can be isolated from the system, facilitating the staff to load and extract the catalyst.

[0049] See Figure 1 In the upper left part, the first end of the activation branch pipe 202 is connected to the inlet pipe 2, between the inlet boundary valve 201 and the first end of the outlet branch pipe 31. The second end of the activation branch pipe 202 is connected to a dry hydrogen chloride gas source. The activation valve 2021 is arranged in the activation branch pipe 202 to control the on-off of the activation branch pipe 202. By using the activation branch pipe 202 and the activation valve 2021, dry hydrogen chloride gas can be quantitatively introduced into the tube-side heat exchange tubes of the converter 1, enabling the fresh catalyst to reach the activation state, which is beneficial to improving the synthesis reaction efficiency.

[0050] See Figure 1 In the upper part, the inlet flowmeter 203 is arranged in the inlet pipe 2, downstream of the connection between the inlet pipe 2 and the first end of the activation branch pipe 202 and upstream of the connection between the inlet pipe 2 and the first end of the inlet branch pipe 21, that is, arranged upstream of the converter 1, which is beneficial for accurate measurement. The inlet flow regulating valve 302 is arranged between the first end of the outlet branch pipe 31 and the outlet boundary valve 301, that is, arranged downstream of the converter 1. Figure 1 The dotted line in it indicates the cascade control of the inlet flowmeter 203 and the gas flow regulating valve 302, which is convenient for quantitatively controlling the reaction, and thus controlling and improving the acetylene conversion rate.

[0051] See Figure 1At the lower part of, the intake air thermometer 204 and the intake air pressure gauge 205 are adjacent to each other and are respectively arranged in the intake pipe 2, between the intake air flowmeter 203 and the first end of the outlet branch pipe 31, and are respectively used to measure the temperature and pressure of the intake air.

[0052] See Figure 1 At the upper right part of, the thermocouple temperature sensor 101 is arranged in the tube bundle of the converter 1 and is used to measure the reaction temperature inside the converter 1.

[0053] The following combines with Figure 2 , 3 to illustrate the process and beneficial effects of this conversion system:

[0054] When the fresh catalyst is installed in the tube-side heat exchange tubes, see Figure 2 , open the main intake tangential valve 211 and the main outlet tangential valve 311, and close the auxiliary intake tangential valve 212 and the auxiliary outlet tangential valve 312. The gas phase moves in the direction indicated by the arrow in Figure 2 , that is, the mixed gas of acetylene and hydrogen chloride passes through the main intake pipe 20, enters the converter 1 from the lower port 11 of the tube side, moves upward in the tube-side heat exchange tubes and contacts the catalyst, undergoes a synthesis reaction to generate vinyl chloride gas, then enters the main outlet pipe 30 through the upper port 12 of the tube side, and then exits through the outlet pipe 3.

[0055] As the usage time of the catalyst extends, the catalyst at the lower part of the tube-side heat exchange tubes gradually ages and its activity decreases, and the main reaction zone will move upward in the converter. At this time, see Figure 3 , open the auxiliary intake tangential valve 212 and the auxiliary outlet tangential valve 312, and close the main intake tangential valve 211 and the main outlet tangential valve 311. The gas phase moves in the direction indicated by the arrow in Figure 3 , that is, the mixed gas of acetylene and hydrogen chloride passes through the intake branch pipe 21, enters the converter 1 from the upper port 12 of the tube side, moves downward in the tube-side heat exchange tubes and contacts the un-aged catalyst at the upper part, undergoes a synthesis reaction to generate vinyl chloride gas, then enters the outlet branch pipe 31 through the lower port 11 of the tube side, and then exits through the outlet pipe 3.

[0056] That is to say, when the catalyst is used for a period of time, by using the main intake tangential valve 211, the auxiliary intake tangential valve 212, the main outlet tangential valve 311, and the auxiliary outlet tangential valve 312 to switch the flow direction of the gas phase in the converter, the catalyst with higher activity in the converter can be fully utilized, not only can the utilization rate of the catalyst be improved, the catalyst activity can be fully utilized, and there is no need to perform the operation of turning over the catalyst, which greatly saves the catalyst replacement time and replacement cost, and can also reduce the harm caused by the catalyst to the human body.

[0057] A vinyl chloride synthesis process system with strong practicability provided by the utility model is easy to operate, and can solve the problems of low catalyst utilization rate, the need to spend manpower and time to turn over the catalyst, extended production cycle and increased production cost caused by the aging of the catalyst in the lower part of the tube side of the converter in the vinyl chloride production process by the synthesis method. It has strong practicability and is suitable for popularization.

Claims

1. A highly practical vinyl chloride synthesis process system, including a converter (1), the converter (1) having tube-side heat exchange tubes and a shell-side channel, a catalyst can be installed in the tube-side heat exchange tubes, and a flowing coolant can be installed in the shell-side channel, characterized in that, it further includes an inlet pipe (2), an outlet pipe (3), an inlet branch pipe (21), an outlet branch pipe (31), an inlet main tangential valve (211), an inlet sub-tangential valve (212), an outlet main tangential valve (311), and an outlet sub-tangential valve (312), the inlet pipe (2) is connected to the lower port (11) of the tube side of the converter (1) to input a mixed gas of acetylene and hydrogen chloride into the tube-side heat exchange tubes of the converter (1), the outlet pipe (3) is connected to the upper port (12) of the tube side of the converter (1) to output vinyl chloride gas from the tube side of the converter (1), the first end of the inlet branch pipe (21) is connected to the inlet pipe (2), and the second end is connected to the upper port (12) of the tube side. The inlet sub-tangential valve (212) is used to control the on-off of the inlet branch pipe (21), the pipe segment of the inlet pipe (2) located downstream of the first end of the inlet branch pipe (21) serves as the inlet main pipe (20). The inlet main tangential valve (211) is used to control the on-off of the inlet main pipe (20), the first end of the outlet branch pipe (31) is connected to the outlet pipe (3), and the second end is connected to the lower port (11) of the tube side. The outlet sub-tangential valve (312) is used to control the on-off of the outlet branch pipe (31), the pipe segment of the outlet pipe (3) located upstream of the first end of the outlet branch pipe (31) serves as the outlet main pipe (30). The outlet main tangential valve (311) is used to control the on-off of the outlet main pipe (30).

2. The utility model relates to a highly practical vinyl chloride synthesis process system according to claim 1, characterized in that, It further includes a coolant inlet pipe (41) and a coolant outlet pipe (42), the shell-side inlet (401) of the converter (1) is located below the shell-side outlet (402), the coolant inlet pipe (41) is connected to the shell-side inlet (401), and the coolant outlet pipe (42) is connected to the shell-side outlet (402).

3. The vinyl chloride synthesis process system with strong practicability according to claim 2, characterized in that, An inlet boundary valve (201), an outlet boundary valve (301), an activation branch pipe (202), and an activation valve (2021) are also provided, the inlet boundary valve (201) is arranged in the inlet pipe (2), upstream of the first end of the inlet branch pipe (21), the outlet boundary valve (301) is arranged in the outlet pipe (3), downstream of the first end of the outlet branch pipe (31), the first end of the activation branch pipe (202) is connected to the inlet pipe (2), between the inlet boundary valve (201) and the first end of the outlet branch pipe (31). The second end of the activation branch pipe (202) is connected to a dry hydrogen chloride gas source, the activation valve (2021) is arranged in the activation branch pipe (202) to control the on-off of the activation branch pipe (202).

4. The vinyl chloride synthesis process system with strong practicability according to claim 3, characterized in that, It further includes an intake air flowmeter (203), which is arranged in the intake air pipe (2), downstream of the connection between the intake air pipe (2) and the first end of the activation branch pipe (202), and upstream of the connection between the intake air pipe (2) and the first end of the intake air branch pipe (21).

5. The utility model relates to a highly practical vinyl chloride synthesis process system according to claim 4, characterized in that It further includes an intake air flow regulating valve (302), which is arranged between the first end of the outlet branch pipe (31) and the outlet boundary valve (301).

6. The practical vinyl chloride synthesis process system according to claim 5, characterized in that, The intake air flowmeter (203) and the air flow regulating valve (302) are under cascade control.

7. The practical vinyl chloride synthesis process system according to any one of claims 4 to 6, characterized in that, It further includes an intake air thermometer (204), which is arranged in the intake air pipe (2) and on the downstream side of the intake air flowmeter (203).

8. A highly practical vinyl chloride synthesis process system according to any one of claims 4 to 6, characterized in that, It further includes an intake air pressure gauge (205), which is arranged in the intake air pipe (2) and on the downstream side of the intake air flowmeter (203).

9. A highly practical vinyl chloride synthesis process system according to any one of claims 4 to 6, characterized in that, A thermocouple temperature sensor (101) for detecting the bed temperature is arranged inside the converter (1).

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