Organic silicon monomer synthesis reactor

Abstract

The utility model relates to the technical field of organic silicon, in particular to an organic silicon monomer synthesis reactor which comprises a shell, a gas inlet is formed in the bottom of the shell, a gas outlet is formed in the top of the shell, and a distribution area, a gas-solid mixing area, a reaction area and a sedimentation area are sequentially arranged in the shell from bottom to top. A gas inlet in the bottom of the shell is composed of a bent pipe and a straight pipe which are sequentially connected, an arc-shaped flow guide plate is arranged in the center of the bent pipe, a flow divider is arranged at an outlet of the bent pipe of the distribution area, and a grating plate is arranged above the flow divider. A plurality of silicon powder inlets and auxiliary gas inlets with vertically upward pipe orifices are uniformly formed in the shell of the gas-solid mixing area along the radial direction; and a heat exchange tube bundle is arranged in the reaction area. The device is simple in structure, not easy to block, capable of stably running for a long period, uniform in gas and silicon powder mixing, uniform in temperature distribution, small in temperature difference and high in reaction efficiency.

Description

Technical Field

[0001] This utility model relates to the field of organosilicon technology, specifically to an organosilicon monomer synthesis reactor. Background Technology

[0002] Organosilicon materials are a new type of chemical material widely used in aerospace, automotive, electronics, light industry, daily chemicals, and medical and health industries, with demand continuously increasing. The organosilicon monomer synthesis reactor is the core equipment in organosilicon production. Inside the reactor, gaseous chloromethane and solid silicon powder react under the action of a copper-based catalyst to produce organosilicon monomers. The operating temperature is 270℃.

[0003] The reaction temperature is ~340℃, and the reaction process releases a large amount of heat.

[0004] Currently, organosilicon monomer synthesis reactors typically employ a fluidized bed structure. Gas enters the tube box through an inner tube and then contacts the silicon powder entering the reactor via a distribution plate, causing the silicon powder to fluidize within the reactor and react to generate organosilicon monomers. The distribution plate is either a flat plate sieve or a conical sieve. Heat exchange tubes containing heat transfer oil are installed inside the reactor to absorb the large amount of heat generated during the reaction. However, this process presents the following problems: 1. Uneven gas distribution, unstable bed height, and large temperature fluctuations; 2. The distribution plate is prone to clogging, which can lead to channeling and short circuits, affecting reactor operation; 3. Large silicon powder particle size and long reaction time result in significant wear on the heat exchange tubes; 4. The heat transfer oil enters the heat exchange tubes through an oil collection tank, leading to uneven flow distribution within each tube and uneven temperature distribution within the reactor, potentially causing localized overheating. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems and provide an organosilicon monomer synthesis reactor that is simple in structure, not easy to clog, can operate stably for a long period of time, has uniform mixing of gas and silicon powder, uniform temperature distribution, small temperature difference, and high reaction efficiency.

[0006] The technical solution includes a shell with a gas inlet at the bottom and a gas outlet at the top. The shell contains, from bottom to top, a distribution zone, a gas-solid mixing zone, a reaction zone, and a settling zone. The gas inlet at the bottom of the shell consists of a series of connected curved and straight pipes. An arc-shaped guide plate is located at the center of the curved pipe. A flow divider is located at the outlet of the curved pipe in the distribution zone, and a grid plate is located above the flow divider. Multiple vertically upward-pointing silicon powder inlets and auxiliary gas inlets are evenly arranged radially on the shell surface of the gas-solid mixing zone. A heat exchange tube bundle is located within the reaction zone.

[0007] The bending radius of the bend is ≥1.5D.

[0008] The splitter consists of multiple concentric cones.

[0009] The spacing between the grating plates is 20–260 mm.

[0010] The auxiliary gas inlet is located above the silicon powder inlet.

[0011] The shell of the gas-solid mixing zone is a cone, and the distribution circle diameter of the multiple auxiliary gas inlets in the shell is larger than the distribution circle diameter of the silicon powder inlet.

[0012] The cone apex angle of the cone in the gas-solid mixing zone is 15° to 90°.

[0013] The heat exchange tube bundle is composed of multiple sets of U-shaped heat exchange tubes connected in parallel. Each set of U-shaped heat exchange tubes has multiple passes, and the inlet and outlet of adjacent sets of U-shaped heat exchange tubes are arranged alternately.

[0014] Each U-shaped heat exchanger tube outlet is equipped with a regulating valve.

[0015] The reaction zone consists of a lower straight section and an upper expanded section.

[0016] The inner surface of the silicon powder inlet and the inner surface of the shell in the gas-solid mixing zone are coated with a wear-resistant material layer.

[0017] Beneficial effects:

[0018] 1) The distribution plate is eliminated. The gas inlet consists of a series of bends and straight pipes. An arc-shaped guide plate is set at the center of the bend. At the same time, a flow divider and a grid plate are set in the gas distribution area to ensure that the airflow is evenly distributed and that solid-containing gas is not easy to deposit and block in the high-speed area.

[0019] 2) Multiple vertically upward silicon powder inlets and auxiliary gas inlets are set in the gas-solid mixing zone. Auxiliary gas is further added in this zone to drive the refluxed silicon powder and improve the uniform mixing effect of silicon powder and catalyst. Preferably, the auxiliary gas inlet is located above the silicon powder inlet, which can further improve the gas-solid mixing efficiency.

[0020] 3) The heat exchange tube bundle adopts multiple sets of U-shaped tubes connected in parallel. Each set of U-shaped tubes is equipped with a regulating valve at the outlet. The heat exchange tubes are evenly distributed and the inlet and outlet are alternately set to ensure uniform temperature and small temperature difference in the reaction zone, avoid local overheating, and improve reaction efficiency.

[0021] 4) A settling zone is set up above the reaction zone. Some unreacted silicon powder settles in this zone and re-enters the reaction zone for further reaction, reducing the solid content of the gas in the reactor outlet and reducing the load on the subsequent cyclone separator.

[0022] 5) This utility model has a simple structure, is not easy to clog, can operate stably for a long period of time, mixes gas and silicon powder evenly, has uniform temperature distribution, small temperature difference, and high reaction efficiency. Attached Figure Description

[0023] Figure 1This is a schematic diagram of the structure of this utility model.

[0024] Figure 2 This is a top view of the heat exchange tube bundle arrangement in this reaction zone.

[0025] Among them, 1-gas inlet, 2-bend, 3-arc guide plate, 4-straight pipe, 5-distributor, 6-grating plate, 7-silicon powder inlet, 8-auxiliary gas inlet, 9-cone, 10-straight section, 11-expanding section, 12-U-shaped heat exchange tube, 13-U-shaped heat exchange tube inlet, 14-settling zone cylinder, 15-upper head, 16-outlet, 17-regulating valve, 18-U-shaped heat exchange tube outlet. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product or device.

[0028] The shell contains, from bottom to top, a distribution zone, a gas-solid mixing zone, a reaction zone, and a settling zone. The gas inlet 1 at the bottom of the shell consists of a bent pipe 2 and a straight pipe 4 connected in sequence. The bending radius of the bent pipe is ≥1.5D, preferably 3D. An arc-shaped guide plate 3, adapted to the bending radius of the bent pipe, is located at the center of the bent pipe 2 in the distribution zone. A flow divider 5, composed of multiple concentric cones, is located above the flow divider 5.

[0029] In another embodiment, the diverter 5 consists of 2 to 4 concentric cones, with several flow channels formed between the cones. The spacing between the grid plates 6 is 20 to 260 mm. The grid plates 6 and the diverter 5 are located in the lower half of the cones 9. This area has a small flow area and a high flow velocity, generally higher than the particle carry-out velocity, preventing particles from depositing on the grid plates 6 and the diverter 5. Furthermore, the flow channel dimensions of the grid plates 6 and the diverter 5 are much larger than the aperture of traditional distribution plates, preventing reactor clogging.

[0030] The shell of the gas-solid mixing zone is a conical cylinder 9 with a cone apex angle of 15°–90°, preferably 30°–60°. Multiple vertically upward-pointing silicon powder inlets 7 and auxiliary gas inlets 8 are evenly arranged radially on the conical cylinder, with the auxiliary gas inlets 8 located above the silicon powder inlets 7. The diameter of the distribution circle of the multiple auxiliary gas inlets 8 on the shell is larger than the diameter of the distribution circle of the silicon powder inlets 7. A wear-resistant material layer is sprayed onto the inner surface of the silicon powder inlets 7 and the inner surface of the shell of the gas-solid mixing zone to improve local wear resistance. There are 2–20 vertically upward-pointing silicon powder inlets 7, preferably 2–8, and 2–20 vertically upward-pointing auxiliary gas inlets 8, preferably 2–8.

[0031] The shell of the reaction zone consists of a lower straight cylindrical section 10 and an upper expanded diameter section 11, and contains a heat exchange tube bundle. The heat exchange tube bundle is composed of multiple sets of U-shaped heat exchange tubes 12 connected in parallel. Each set of U-shaped heat exchange tubes 12 has multiple passes, and the inlet and outlet of adjacent sets of U-shaped heat exchange tubes 12 are arranged alternately; that is, the inlet of the next set of U-shaped heat exchange tubes 12 is close to the outlet of the previous set, and the outlet of the next set is close to the inlet of the previous set. In this embodiment, the medium inside the U-shaped heat exchange tubes 12 is heat transfer oil. This inlet and outlet arrangement of the heat exchange tube bundle ensures a uniform temperature distribution in the reaction zone. Simultaneously, each set of U-shaped heat exchange tubes 12 is equipped with a regulating valve 17. Based on the measured temperature inside the reactor and the outlet temperature of the heat transfer oil, the flow rate of the heat transfer oil in the heat exchange tubes is adjusted via the regulating valve 17, resulting in a more uniform temperature distribution in the reaction zone, preventing local overheating, reducing the temperature difference in the reaction zone, and improving reaction efficiency.

[0032] As a specific example: See Figure 2 The heat exchanger tube bundle is arranged in 7 groups of U-shaped heat exchanger tubes connected in parallel. The 1st, 2nd, 6th and 7th groups of U-shaped heat exchanger tubes have 8 passes, and the 3rd, 4th and 5th groups of U-shaped heat exchanger tubes have 10 passes. Each pass of heat exchanger tubes adopts a square tube arrangement. Each group of U-shaped heat exchanger tubes is equipped with a heat exchanger tube outlet regulating valve. The inlet of the 1st, 3rd, 5th and 7th groups of U-shaped heat exchanger tubes is on the same side as the outlet of the 2nd, 4th and 6th groups of U-shaped heat exchanger tubes. The outlet of the 1st, 3rd, 5th and 7th groups of U-shaped heat exchanger tubes is on the same side as the inlet of the 2nd, 4th and 6th groups of U-shaped heat exchanger tubes.

[0033] Process:

[0034] Chloromethane gas enters the bend 2 through the chloromethane gas inlet 1. The bend 2 is equipped with an arc-shaped guide plate 3 to make the gas flow velocity in the pipe uniformly distributed. After distribution, the gas flows into the distributor 5 of the distribution area through the straight pipe 4, which makes the gas split and further uniformly distributed. Then the gas enters the grid plate 6, and under the action of the grid plate 6, the gas is uniformly distributed again, and then enters the gas-solid mixing zone.

[0035] In the gas-solid mixing zone, fine silicon powder (including fresh silicon powder and recycled silicon powder) and catalyst enter the gas-solid mixing zone through silicon powder inlet 7. Under the action of uniformly distributed gas, the fine silicon powder and catalyst are uniformly mixed with the gas and are in a fluidized state. They then enter the reaction zone. Auxiliary chloromethane gas enters the gas-solid mixing zone through auxiliary gas inlet 8. The recycled silicon powder re-enters the reaction zone under the action of the auxiliary chloromethane gas, improving the reaction efficiency. The fine silicon powder has a particle size of 6-100 μm, preferably 20-30 μm. Using fine-particle silicon powder increases the reaction contact area, improves reaction efficiency, and reduces the abrasion of the reactor by the silicon powder.

[0036] Fine silica powder and chloromethane gas react in the reaction zone under the action of a catalyst to generate organosilicon monomers. The operating temperature is 270℃~340℃, and the reaction process releases a large amount of heat. Multiple sets of U-shaped heat exchange tube bundles 12 are installed in the reaction zone. The medium inside the heat exchange tubes can absorb the heat of reaction, and is generally heat transfer oil.

[0037] The heat transfer oil in the U-shaped heat exchange tube bundle 12 absorbs the heat released by the reaction medium in the reaction zone, and the temperature of the heat transfer oil rises. The flow rate of the heat transfer oil in the heat exchange tube is adjusted by the regulating valve 17, so that the temperature distribution in the reaction zone is more uniform, avoiding local overheating, reducing the temperature difference in the reaction zone, and improving the reaction efficiency.

[0038] After the reaction in the reaction zone, the medium continues to rise into the settling zone. The diameter of the cylinder 14 in the settling zone increases and the flow rate decreases. Some unreacted silicon powder settles in this area and re-enters the reaction zone for further reaction, reducing the solid content of the gas in the top outlet 16 of the reactor, reducing the load on the cyclone separator at the reactor outlet, and improving the reaction efficiency.

[0039] The above is a further detailed description of the present invention and should not be considered as a limitation on the specific implementation of the present invention. For those skilled in the art, simple deductions or substitutions without departing from the concept of the present invention are all within the protection scope of the present invention.

Claims

1. A reactor for synthesizing organosilicon monomers, comprising a shell, wherein a gas inlet is provided at the bottom of the shell and a gas outlet is provided at the top, characterized in that, The shell contains, from bottom to top, a distribution zone, a gas-solid mixing zone, a reaction zone, and a settling zone. The gas inlet at the bottom of the shell consists of a series of connected curved and straight pipes. An arc-shaped guide plate is provided at the center of the curved pipe. A flow divider is provided at the outlet of the curved pipe in the distribution zone, and a grid plate is provided above the flow divider. Multiple vertically upward silicon powder inlets and auxiliary gas inlets are uniformly arranged radially on the shell of the gas-solid mixing zone. A heat exchange tube bundle is provided in the reaction zone.

2. The organosilicon monomer synthesis reactor as described in claim 1, characterized in that, The bending radius of the bend is ≥1.5D.

3. The organosilicon monomer synthesis reactor as described in claim 1, characterized in that, The splitter consists of multiple concentric cones.

4. The organosilicon monomer synthesis reactor according to any one of claims 1-3, characterized in that, The spacing between the grating plates is 20–260 mm.

5. The organosilicon monomer synthesis reactor as described in claim 1, characterized in that, The auxiliary gas inlet is located above the silicon powder inlet.

6. The organosilicon monomer synthesis reactor as described in claim 5, characterized in that, The shell of the gas-solid mixing zone is a cone, and the distribution circle diameter of the multiple auxiliary gas inlets in the shell is larger than the distribution circle diameter of the silicon powder inlet.

7. The organosilicon monomer synthesis reactor as described in claim 5 or 6, characterized in that, The cone apex angle of the cone in the gas-solid mixing zone is 15° to 90°.

8. The organosilicon monomer synthesis reactor as described in claim 1, characterized in that, The heat exchange tube bundle is composed of multiple sets of U-shaped heat exchange tubes connected in parallel. Each set of U-shaped heat exchange tubes has multiple passes, and the inlet and outlet of adjacent sets of U-shaped heat exchange tubes are arranged alternately.

9. The organosilicon monomer synthesis reactor as described in claim 8, characterized in that, Each U-shaped heat exchanger tube outlet is equipped with a regulating valve.

10. The organosilicon monomer synthesis reactor as described in claim 1, characterized in that, The reaction zone consists of a lower straight section and an upper expanded section.

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