Propylene degassing device for purifying raw material propylene

Abstract

The utility model discloses a propylene degassing device for purifying raw material propylene. The propylene degassing device comprises a condenser, a heat exchanger, a degassing tower, a connecting cylinder, a liquid collecting tray and a concentric pipe, the heat exchanger is accommodated in the condenser; the concentric pipe is accommodated in the center of the heat exchanger and is communicated with a sealing head at the upper part of the condenser and the degassing tower; the degassing tower is arranged at the top of the connecting cylinder; the degassing tower is arranged at the bottom of the connecting cylinder; the liquid collecting tray is accommodated in the connecting cylinder; one end of the exhaust branch pipe is communicated with the sealing head, and the other end of the exhaust branch pipe is communicated with the gas-phase exhaust pipe. According to the device, the light component separation effect of the degassing tower can be improved, the proportion of the light components at the end socket can be effectively reduced, and the light components can be effectively removed under the condition of not increasing the discharge amount.

Description

Technical Field

[0001] This application relates to the field of propylene degassing tower production technology, and in particular to a propylene degassing device for propylene purification. Background Technology

[0002] The propylene degassing tower utilizes the boiling point difference between light components and propylene to separate trace amounts of light component poisons from the top of the tower through distillation, meeting the purity requirements of polymerization production. Currently, the degassing tower's top condenser and tower body are integrated, which saves on equipment procurement and operating costs for reflux pumps, separation tanks, and related pipelines. The material entering the propylene degassing tower is propylene feedstock liquid. After processing in the degassing tower, the light components contained in the feedstock need to be separated, and impurities need to be removed from the propylene feedstock to meet the requirements of subsequent processing.

[0003] The material processed by the degassing tower needs to be usable as polymer-grade propylene. The purity of polymer-grade propylene is ≤1ppmv for the light component. However, the existing degassing towers have a limited number of trays, only 30. To ensure the removal effect, the concentration of propylene collected from the top of the tower needs to be controlled at a high level (the concentration of propylene in the middle component needs to be >80%). This requires increasing the flow rate of the raw propylene to ensure that the composition of the discharged gas phase meets the requirements when the area where the liquid collection tray is located is the gas-liquid separation zone. This results in a high consumption of raw propylene.

[0004] Theoretically, after condensation and separation, the propylene content in the upper space of the collecting pan should be at a low point. However, in reality, by the time the rising gas stream reaches the top of the column after passing through each tray of distillation, the content of light components is already relatively high. When it reaches the top end cap of the heat exchanger at the top of the column, the non-condensable gas is lighter and floats at end cap 132 without descending. This prolonged floating causes the column pressure to rise, reducing the removal efficiency of the degassing column for light components (gas phase). To maintain the degassing effect, the emission rate must be increased.

[0005] In actual production, the gas phase discharged from the collection pan was sampled and tested. The results showed that the mass ratio of propylene component in the gas phase was 90.8%, while the mass ratio of light component was only 9.1%. This indicates that when using this device to extract propylene raw material, the separation efficiency of light component is low, and the two cannot be effectively separated.

[0006] The information disclosed in the background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Utility Model Content

[0007] This application addresses the aforementioned technical problems by providing a propylene degassing device for propylene purification. This device can improve the separation effect of the degassing tower on light components, effectively reduce the proportion of light components at the end cap, and ensure the effective removal of light components without increasing emissions.

[0008] This application provides a propylene degassing device for propylene purification, comprising: a condenser, a heat exchanger, a degassing tower, a connecting cylinder, a liquid collecting tray, and a concentric tube;

[0009] The heat exchanger is housed inside the condenser; the concentric tube is housed in the center of the heat exchanger and connects to the head and degassing tower at the top of the condenser.

[0010] The degassing tower is located at the top of the connecting cylinder; the degassing tower is located at the bottom of the connecting cylinder; the liquid collection tray is located inside the connecting cylinder; one end of the exhaust branch pipe is connected to the end cap, and the other end is connected to the gas phase discharge pipe.

[0011] Preferably, the heat exchanger includes: a heat exchange shell, heat exchange tubes, and a mounting flange; the heat exchange tubes are housed within the heat exchange shell; the mounting flange is located on the periphery of the heat exchange shell; and the heat exchanger is detachably connected to the condenser via the mounting flange.

[0012] Preferably, it includes: a circulating hot water storage tank and a circulating pump; the outlet of the circulating hot water storage tank is connected to the inlet of the heat exchange shell via a pipeline; the inlet of the circulating hot water storage tank is connected to the outlet of the heat exchange shell via a pipeline; and the circulating pump is installed on the pipeline connecting the outlet of the circulating hot water storage tank and the inlet of the heat exchange shell.

[0013] Preferably, the condenser, heat exchanger, degassing tower, connecting cylinder, liquid collection tray, and concentric tube are arranged coaxially.

[0014] Preferably, the condenser includes: a heat exchange chamber; a head disposed on the top surface of the heat exchange chamber; and a heat exchange shell disposed within the heat exchange chamber.

[0015] Preferably, it includes: a liquid reflux pipe; one end of the liquid reflux pipe is connected to a liquid collection tray, and the other end is connected to the top of the degassing tower.

[0016] Preferably, it includes: an exhaust pipe; the exhaust pipe is disposed on the end cap; one end of the exhaust branch pipe is connected to the exhaust pipe.

[0017] Preferably, it includes: multiple valves; the valves are disposed at both ends of the exhaust branch pipe; the valves are disposed on the exhaust pipe.

[0018] Preferably, it includes: a safety valve; the safety valve is disposed on the exhaust pipe;

[0019] One end of the gas phase discharge pipe is connected to the connecting cylinder.

[0020] Preferably, it includes: a PLC control module, a flow meter, and a regulating valve; the flow meter and the regulating valve are spaced apart on the gas phase discharge pipe; the PLC control module is electrically connected to the flow meter and the regulating valve respectively.

[0021] The beneficial effects that this application can produce include:

[0022] 1) The propylene degassing device for propylene purification provided in this application effectively reduces the propylene content in the obtained gaseous substance by setting a condenser at the top of the degassing tower and collecting gaseous substances from the top of the condenser. It can reduce the proportion of propylene in the obtained gaseous substance at the original propylene flow rate, effectively achieve the separation of light phase components from propylene in the propylene raw material, improve separation efficiency, and reduce raw material waste. Attached Figure Description

[0023] Figure 1 A schematic diagram of a propylene degassing device for propylene purification in at least one embodiment provided in this application;

[0024] Figure 2 A front perspective view of the condenser in at least one embodiment provided in this application;

[0025] Figure 3 for Figure 2 AA sectional view;

[0026] Figure 4 A schematic diagram of the module connection structure in at least one embodiment provided in this application;

[0027] Legend:

[0028] Condenser 1, Safety Valve 11, Heat Exchange Tubes 122, End Cap 132, Heat Exchange Chamber 124, Concentric Tube 125, End Cap 132, Heat Exchange Shell 133, Circulating Hot Water Storage Tank 5, Circulating Pump 134, Degassing Tower 3, Connecting Cylinder 31, Liquid Phase Return Pipe 21, Exhaust Pipe 13, Liquid Collection Pan 131, Mounting Flange 135, Gas Phase Exhaust Pipe 22, Flow Meter 213, Regulating Valve 212, Exhaust Branch Pipe 12, Control Valve 211, PLC Control Module 214. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] The controller used in this implementation scheme is an existing structure, and the control circuit can be implemented by those skilled in the art through simple programming. It is common knowledge in the field, and it is only used without modification. Therefore, the control method and circuit connection will not be described in detail.

[0032] Technical means not detailed in this application and not used to solve the technical problems of this application are all set according to common general knowledge in the field, and multiple common general knowledge setting methods can be implemented.

[0033] See Figures 1-4 The propylene degassing device for propylene purification provided in this application includes: a degassing tower 3 and a condenser 1; the condenser 1 is disposed at the top of the degassing tower 3 and is connected to the degassing tower 3 through a concentric tube 125; the condenser 1 includes: a head 132, a heat exchange tube 122, and a heat exchange chamber 124; one end of the concentric tube 125 extends into the center of the heat exchange tube 122 and is installed in the heat exchange tube 122; the heat exchange tube 122 is housed in the heat exchange shell 133; both ends of the heat exchange tube 122 are respectively provided with openings and are installed in the heat exchange chamber 124.

[0034] One end of the concentric tube 125 is connected to the inner cavity of the degassing tower 3, and is used to pass the gas discharged from the degassing tower 3 into the condenser 1. The end cap 132 is installed on the top of the heat exchange chamber 124; the exhaust port of the concentric tube 125 is opened inside the end cap 132. After the rising gas-liquid mixture is blocked by the end cap 132, it enters the heat exchange tube 122 and exchanges heat with the circulating coolant in the heat exchange shell 133, liquefies, and flows back into the liquid collection tray 131; the liquid collection tray 131 is connected to the upper part of the degassing tower 3 through the liquid phase return pipe 21 to realize the return of the liquid phase, so as to perform multiple gas-liquid separations on the liquid phase, improve the separation efficiency, and reduce the propylene content in the discharged gas phase.

[0035] Unliquefied material inside condenser 1 continues to move upward into end cap 132 and is discharged through exhaust pipe 13 connected to end cap 132; exhaust pipe 13 is connected to gas phase discharge pipe 22 through exhaust branch pipe 12.

[0036] This device condenses the gas-liquid mixture discharged from degassing tower 3, and collects the gaseous phase discharged from the top of condenser 1. Without increasing the number of trays in degassing tower 3 or increasing the feed flow rate, it improves the separation efficiency of propylene and light phase components in the gaseous material, increases the proportion of light phase components in the separated gaseous material, and achieves better separation. After processing with this device, the gaseous phase containing light components is discharged to a flare for combustion, while the liquid phase is used as reflux in a distillation column.

[0037] In one specific embodiment, one end of the exhaust pipe 13 is connected to the condenser 1, and the other end extends outward; the extended end and the connecting end of the exhaust pipe 13 are connected to the exhaust branch pipe 12. With this configuration, gaseous substances can be discharged to other equipment for processing as needed through the extended end.

[0038] In one specific embodiment, a safety valve 11 is included; the safety valve 11 is disposed on the extension end of the exhaust pipe 13. When it is necessary to discharge the separated gaseous substances through the exhaust branch pipe 12, the safety valve 11 is closed to ensure that all gaseous substances are discharged from the exhaust branch pipe 12.

[0039] In one specific embodiment, it includes: a connecting cylinder 31 and a liquid phase reflux pipe 21; the connecting cylinder 31 is disposed between the degassing tower 3 and the condenser 1; a liquid collecting tray 131 and a section of the concentric tube 125 are accommodated in the connecting cylinder 31; the liquid collecting tray 131 is disposed opposite to the bottom opening of the heat exchange tube 122 so as to receive liquid phase substances; the liquid collecting tray 131 is connected to the degassing tower 3 through the liquid phase reflux pipe 21, thereby realizing the re-entry and separation of liquid phase substances into the tower and improving the separation efficiency.

[0040] In one specific embodiment, a concentric tube 125 passes through the central region of the liquid collection tray 131. The liquid collection tray 131, the concentric tube 125, the condenser 1, and the degassing tower 3 are arranged coaxially.

[0041] In one specific embodiment, it includes: a flow meter 213 and a regulating valve 212; the flow meter 213 and the regulating valve 212 are spaced apart on the gas phase discharge pipe 22, and are specifically installed on the pipeline outside the connection point between the gas phase discharge pipe 22 and the exhaust branch pipe 12, so as to effectively control the gas phase substances discharged from the gas phase discharge pipe 22.

[0042] In one specific embodiment, the system includes a PLC control module 214, which is electrically connected to a flow meter 213 and a regulating valve 212. The flow meter 213 measures the flow velocity of the gaseous substance in the gas discharge pipe 22 and sends an electrical signal to the PLC control module 214 based on the flow velocity. The PLC control module 214 then controls the opening of the regulating valve 212 in real time based on the obtained flow velocity, thereby controlling the outward flow rate of the gaseous substance.

[0043] In one specific embodiment, it includes: a plurality of control valves 211; the control valves 211 are respectively disposed on the inlet and outlet ends of the exhaust branch pipe 12, thereby controlling the discharge of gaseous substances.

[0044] In one specific embodiment, the system includes: a circulating hot water storage tank 5 and a circulating pump 134; the inlet of the circulating hot water storage tank 5 is connected to the outlet of the heat exchange shell 133 via a pipeline; the outlet of the circulating hot water storage tank 5 is connected to the inlet of the heat exchange shell 133 via a pipeline; the circulating pump 134 is installed on the pipeline connecting the outlet of the circulating hot water storage tank 5 and the inlet of the heat exchange shell 133. This configuration allows for adjustment of the flow rate of the circulating liquid entering the heat exchange shell 133 according to condensation requirements.

[0045] In one specific embodiment, it includes: mounting flange 135; mounting flange 135 is disposed on the periphery of the top and bottom surfaces of heat exchange shell 133, and bolt assembly is used to realize the detachable connection between heat exchange shell 133 and the inner cavity of condenser 1.

[0046] In one specific embodiment, a valve 211 is provided on the exhaust pipe 13; the valve 211 is located between the connecting cylinder 31 and the exhaust branch pipe 12. It is used to control the discharge of gaseous substances.

[0047] After the above-described device was used in actual production, with the propylene feedstock entering the degassing tower 3 at a flow rate of 13.9 t / h, samples were taken from the drain outlet of the safety valve 11 on the end cap 132 and from the exhaust port of the connecting cylinder 31 where the collection tray 131 is located. The results of the analysis of the propylene and light component content in the samples are shown in Table 1.

[0048] Table 1 Comparison of sampling analysis of degassing towers under the same operating conditions

[0049]

[0050] As shown in Table 1, the test results confirm that by setting the exhaust branch pipe 12 and changing the exhaust phase to exhaust from the exhaust pipe 13 on the end cap 132, the proportion of propylene in the gas sample decreased significantly compared to the proportion at the liquid collection plate, indicating that the device can achieve better separation of propylene feed liquid.

[0051] The flow rate of the propylene feedstock changed little during sampling (13.9 t / h), and good separation results could be obtained without increasing the flow rate of the propylene feedstock.

[0052] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A propylene degassing device for purifying raw propylene, characterized by comprising: Comprise: Condenser (1), heat exchanger, degassing tower (3), connecting cylinder (31), liquid collecting tray (131), concentric tube (125); The heat exchanger is accommodated in the condenser (1); the concentric tube (125) is accommodated in the center of the heat exchanger and is communicated with the head (132) at the upper part of the condenser (1) and the degassing tower (3); The degassing tower (3) is arranged at the top of the connecting cylinder (31); the degassing tower (3) is arranged at the bottom of the connecting cylinder (31); the liquid collecting tray (131) is accommodated in the connecting cylinder (31); one end of the exhaust branch pipe (12) is communicated with the head (132), and the other end is communicated with the gas phase exhaust pipe (22).

2. The raw material propylene purification propylene degassing device according to claim 1, characterized by, The heat exchanger comprises: a heat exchange shell (133), a heat exchange pipe (122), and a mounting flange (135); the heat exchange pipe (122) is accommodated in the heat exchange shell (133); the mounting flange (135) is arranged on the periphery of the heat exchange shell (133); and the mounting flange (135) is detachably connected with the condenser (1).

3. The raw material propylene purification propylene degassing device according to claim 2, characterized by, Comprise: Circulating heat exchange water storage tank (5), circulating pump (134); the liquid outlet of the circulating heat exchange water storage tank (5) is communicated with the liquid inlet of the heat exchange shell (133); the liquid inlet of the circulating heat exchange water storage tank (5) is communicated with the liquid outlet of the heat exchange shell (133); and the circulating pump (134) is arranged on the pipeline communicated between the liquid outlet of the circulating heat exchange water storage tank (5) and the liquid inlet of the heat exchange shell (133).

4. The raw material propylene purification propylene degassing device according to claim 1, characterized by, The condenser (1), the heat exchanger, the degassing tower (3), the connecting cylinder (31), the liquid collecting tray (131), and the concentric tube (125) are coaxially arranged.

5. The raw material propylene purification propylene degassing device according to claim 1, characterized by, The condenser (1) comprises: a heat exchange cavity (124); the head (132) is arranged on the top surface of the heat exchange cavity (124); and the heat exchange shell (133) is accommodated in the heat exchange cavity (124).

6. The raw material propylene purification propylene degassing device according to claim 1, characterized by, Comprise: Liquid phase return pipe (21); one end of the liquid phase return pipe (21) is communicated with the liquid collecting tray (131), and the other end is communicated with the top of the degassing tower (3).

7. The raw material propylene purification propylene degassing device according to claim 1, characterized by, Comprise: Exhaust pipe (13); the exhaust pipe (13) is arranged on the head (132); and one end of the exhaust branch pipe (12) is communicated with the exhaust pipe (13).

8. The raw material propylene purification propylene degassing device according to claim 1, characterized in that, Comprise: A plurality of valves (211); the valves (211) are arranged on both ends of the exhaust branch pipe (12); The valves (211) are arranged on the exhaust pipe (13).

9. The raw material propylene purification propylene degassing device according to claim 1, characterized by, Comprise: Safety valve (11); the safety valve (11) is arranged on the exhaust pipe (13); One end of the gas phase exhaust pipe (22) is connected with the connecting cylinder (31).

10. The raw material propylene purification propylene degassing device according to claim 1, characterized by, Comprise: PLC control module (214), flow meter (213), regulating valve (212); the flow meter (213) and the regulating valve (212) are arranged on the gas phase exhaust pipe (22) at intervals; and the PLC control module (214) is electrically connected with the flow meter (213) and the regulating valve (212) respectively.

Images