A u-tube fluidized bed reactor for methylchlorosilane monomer synthesis

Abstract

A U-shaped tubular fluidized bed reactor for the synthesis of methylchlorosilane monomers includes a cylindrical body and upper and lower end caps respectively installed vertically on the cylindrical body. It also includes a gas-solid phase discharge pipe, a silicon powder feed pipe, a chloromethane inlet pipe on the upper plate, a chloromethane inlet pipe below the plate, an oil inlet pipe, and an oil outlet pipe connected to the cylindrical body. The oil inlet and outlet pipes are connected to the fluidized bed reactor via a semi-tube welded heat transfer oil cavity. Several U-shaped heat exchange tubes are installed inside the cylindrical body, with both ends connected to the oil inlet and outlet cavities. A gas distribution plate is installed at the lower part of the cylindrical body, through which the silicon powder feed pipe passes and connects to the cylindrical body. Several nozzles are installed around the cylindrical body above the gas distribution plate. This design effectively improves the fluidization effect within the fluidized bed, increases the single-pass conversion rate of chloromethane, significantly reduces the pressure difference between the inlet and outlet of the heat exchange tubes, and increases the heat transfer oil throughput.

Description

Technical Field

[0001] This utility model relates to the field of chemical production technology, and in particular to a U-shaped tubular fluidized bed reactor for the synthesis of methylchlorosilane monomers. Background Technology

[0002] Organosilicon is the only synthetic polymer material that does not rely on petroleum resources. It has a unique structure and combines the properties of inorganic and organic materials.

[0003] Fluidized bed reactors are one of the core pieces of equipment in organosilicon production. Due to the complexity and high heat release of the reaction between silicon powder and chloromethane, it is essential to remove the heat from the fluidized bed promptly to maintain a safe and stable reaction. Currently, the organosilicon industry mainly uses finger-shaped tube fluidized bed reactors and U-shaped tube fluidized bed reactors. However, with the national restrictions on the single-unit capacity of organosilicon monomer synthesis equipment, the drawbacks of finger-shaped tube fluidized beds—such as unsatisfactory heat exchange performance, low single-pass conversion rate, and inability to scale up—have become increasingly apparent. Chinese patent CN 211800723U describes a U-shaped tube methylchlorosilane fluidized bed reactor. By arranging different numbers of inner and outer heat exchange tubes within the bed, the heat exchange temperature difference between the inside and outside of the fluidized bed can be balanced, ensuring equal heat exchange effects in the central and peripheral parts. However, due to the different arrangements of the inner and outer heat exchange tubes, there is a risk of excessive local wear and leakage of heat transfer oil caused by some heat exchange tubes being too close together. Furthermore, the overall utilization rate of the heat exchange tubes is relatively low. Summary of the Invention

[0004] The purpose of this invention is to provide a U-shaped tubular fluidized bed reactor for the synthesis of methylchlorosilane monomers, which has a reasonable structure, high heat exchange efficiency, low risk of leakage from the heat transfer oil inlet and outlet pipes, and large production capacity of organosilicon monomers.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a U-shaped tubular fluidized bed reactor for the synthesis of methylchlorosilane monomers, comprising a fluidized bed cylinder and an upper end cap and a lower end cap respectively installed in the vertical direction of the cylinder, and further comprising a gas-solid phase discharge pipe, a silicon powder feed pipe, a chloromethane inlet pipe on the plate, a chloromethane inlet pipe below the plate, an oil inlet pipe and an oil outlet pipe connected to each other, and a ring of heat tracing pipes installed outside the cylinder;

[0006] The fluidized bed reactor is connected to a semi-pipe welded heat transfer oil cavity. Heat exchange tubes are provided on both sides of the fluidized bed cylinder. The heat exchange tubes form a multi-stage U-shaped tube. An oil inlet pipe and an oil outlet pipe are provided at both ends of the heat exchange tubes.

[0007] A gas distribution plate is installed at the bottom of the fluidized bed cylinder, and multiple plate-mounted chloromethane inlets are installed above the gas distribution plate.

[0008] The fluidized bed cylinder extends outward at the location of the heat exchange tube, forming an enlarged section.

[0009] The purpose of the expansion section is to slow down the airflow velocity, allowing large particles of powder in the fluidized bed reactor to return to the reactor and participate in the reaction under gravity, thus reducing the amount of powder carried out of the fluidized bed reactor with the chloromethane gas flow.

[0010] The outer diameter of the semi-tube heat transfer oil chamber is 500~650mm, and it is welded to the enlarged section of the fluidized bed reactor.

[0011] The U-shaped tubes consist of 6 to 10 φ48mm heat exchange tubes connected in series, with 2 to 4 sets of U-shaped tubes flowing into the φ89mm to φ113mm main pipe.

[0012] That is, one set of U-shaped tubes consists of 6 to 10 φ48mm heat exchange tubes connected in series from head to tail.

[0013] The gas distribution plate is a funnel-shaped plate with 3-5mm through holes.

[0014] A gas-solid phase discharge pipe is provided on the upper end cap, connecting the cylinder body; a chloromethane inlet pipe and a silicon powder feed pipe connecting the cylinder body are provided on the lower end cap, the silicon powder feed pipe passing through the gas distribution plate from bottom to top and connecting with the fluidized bed cylinder body.

[0015] The plate is equipped with a nozzle at the chloromethane inlet. The angle between the center line of the nozzle and the normal to the cylinder wall is 40°~50°, and the diameter of the central circle of the formed circulation is 1500mm~2000mm.

[0016] The chloromethane on the plate is also sprayed, with 16-24 nozzles in one ring. This can create disturbance in the core reaction area of ​​the fluidized bed reactor, thereby removing carbon powder (by-reaction product) that is wrapped around the silicon powder and copper powder and allowing it to re-participate in the reaction.

[0017] Compared with the prior art, the advantages of this utility model are as follows:

[0018] 1. The inlet and outlet structure of the fluidized bed heat transfer oil is a semi-pipe structure, which greatly reduces the number of leakage points in the heat transfer oil inlet and outlet pipelines, reduces the amount of maintenance, and can effectively reduce safety risks.

[0019] 2. The single-unit U-tube has reduced resistance and a large heat transfer oil throughput, which can not only effectively improve heat exchange efficiency, but also further reduce the temperature difference between the inlet and outlet of the heat transfer oil under the premise of a certain production capacity, reduce the deformation of the heat transfer oil tube bundle caused by thermal stress, and extend the service life of the tube bundle.

[0020] 3. The parallel connection of the heat transfer oil pipes provides ample maintenance space at the top of the fluidized bed reactor. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic cross-sectional view of the present invention. Wherein, 1. Upper head; 2. Fluidized bed cylinder; 3. Lower head; 4. Gas distribution plate; 5. Chloromethane inlet pipe on the upper plate; 6. Chloromethane inlet pipe below the plate; 7. Silica powder feed pipe; 8. Oil inlet pipe; 9. Oil outlet pipe; 10. U-shaped pipe; 11. Gas-solid phase outlet pipe; 12. Heat tracing pipe. Detailed Implementation

[0023] like Figure 1 As shown: A U-shaped tubular fluidized bed reactor for the synthesis of methylchlorosilane monomers includes a fluidized bed cylinder 2 and an upper end cap 1 and a lower end cap 3 respectively installed in the vertical direction of the cylinder. It also includes a gas-solid phase discharge pipe 11, a silicon powder feed pipe 7, a plate chloromethane inlet pipe 5, a lower plate chloromethane inlet pipe 6, an oil inlet pipe 8, and an oil outlet pipe 9 connected to each other. A ring of heat tracing pipes 12 is installed outside the cylinder.

[0024] The connection to the fluidized bed reactor is a semi-pipe welded heat transfer oil cavity. Several U-shaped heat exchange tubes 10 are installed inside the cylinder. The two ends of the heat exchange tubes are connected to the inlet and outlet oil cavities respectively. A gas distribution plate 4 is installed at the lower part of the cylinder. A plate chloromethane inlet 5 is installed above the gas distribution plate 4, and several nozzles are installed around the cylinder.

[0025] Furthermore, a section of the fluidized bed cylinder 2 extends outward to form an enlarged section.

[0026] Furthermore, the outer diameter of the semi-tube heat transfer oil chamber is 500~650mm, and it is welded to the expansion section of the fluidized bed reactor.

[0027] Furthermore, each U-tube group 10 uses 10 φ48mm heat exchange tubes connected in series, and 4 U-tube groups converge into the φ89mm~φ113mm main pipe.

[0028] Furthermore, the gas distribution plate 4 is a funnel-shaped plate with several through holes evenly spaced on it.

[0029] Furthermore, a gas phase discharge pipe connecting the cylinder is provided on the upper end cap 1; a plate-mounted chloromethane inlet pipe 6 and a silicon powder feed pipe 7 connecting the cylinder are provided on the lower end cap 3, wherein the silicon powder feed pipe 7 passes through the gas distribution plate 4 from bottom to top and is connected to the cylinder 2.

[0030] Furthermore, the angle between the centerline of each nozzle in the chloromethane inlet pipe 5 on the plate and the normal to the cylinder wall is 40°~50°, and the diameter of the central circle of the formed circulation is about 1500mm~1800mm.

[0031] In practical use, silicon powder enters the cylinder 2 above the distribution plate 4 through the silicon powder feed pipe 7 and the lower end cap 3. Chloromethane gas enters the cavity of the lower end cap 3 through the chloromethane feed pipe 6 under the plate. After passing through the gas distribution plate 4, the silicon powder in the cylinder enters the fluidized state. The reaction products are discharged from the gas-solid phase discharge pipe 11. The heat generated during the reaction is carried out through the heat exchange pipe 10.

[0032] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A U-shaped tubular fluidized bed reactor for the synthesis of methylchlorosilane monomers, comprising a fluidized bed cylinder (2) and an upper end cap (1) and a lower end cap (3) respectively installed in the vertical direction of the cylinder, further comprising a gas-solid phase discharge pipe (11), a silicon powder feed pipe (7), a plate chloromethane inlet pipe (5), a lower plate chloromethane inlet pipe (6), an oil inlet pipe (8), and an oil outlet pipe (9) connected to each other, and a ring of heat tracing pipes (12) installed outside the cylinder, characterized in that: Heat exchange tubes are provided on both sides inside the fluidized bed cylinder (2). The heat exchange tubes form a multi-stage U-shaped tube (10). An oil inlet pipe (8) and an oil outlet pipe (9) are provided at both ends of the heat exchange tubes. A gas distribution plate (4) is installed at the bottom of the fluidized bed cylinder, and multiple plate-mounted chloromethane inlet pipes (5) are installed above the gas distribution plate (4).

2. A U-tube fluidized bed reactor for methylchlorosilane monomer synthesis according to claim 1, characterized in that: The fluidized bed cylinder (2) extends outward at the location of the heat exchange tube to form an enlarged section.

3. A U-tube fluidized bed reactor for methylchlorosilane monomer synthesis as claimed in claim 1, wherein: The outer diameter of the semi-tube heat transfer oil chamber is 500~650mm, and it is welded to the expansion section of the fluidized bed reactor.

4. The U-shaped tubular fluidized bed reactor for the synthesis of methylchlorosilane monomers according to claim 1, characterized in that: The U-shaped tube (10) uses 6~10 φ48mm heat exchange tubes connected in series at the head and tail, and 2~4 sets of U-shaped tubes are connected to the φ89mm~φ113mm main tube.

5. A U-tube fluidized bed reactor for methylchlorosilane monomer synthesis as claimed in claim 1, wherein: The gas distribution plate (4) is a funnel-shaped plate with 3-5mm through holes.

6. A U-tube fluidized bed reactor for methylchlorosilane monomer synthesis as claimed in claim 1, wherein: A gas-solid phase discharge pipe is provided on the upper end cap, connecting the cylinder body; a chloromethane inlet pipe and a silicon powder feed pipe connecting the cylinder body are provided on the lower end cap, the silicon powder feed pipe passing through the gas distribution plate from bottom to top and connecting with the fluidized bed cylinder body.

7. A U-tube fluidized bed reactor for methylchlorosilane monomer synthesis as claimed in claim 1, wherein: The plate is equipped with a nozzle at the chloromethane inlet. The angle between the center line of the nozzle and the normal of the cylinder wall is 40°~50°, and the diameter of the central circle of the formed circulation is 1500mm~2000mm.

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