Air inlet combination device of fluidized bed for organic silicon monomer synthesis and organic silicon fluidized bed

Abstract

The utility model provides an air inlet combination device of a fluidized bed for synthesizing an organic silicon monomer and the organic silicon fluidized bed. The air inlet combination device comprises a bottom center hole air inlet and side wall jet air inlet combination mode. The bottom center hole air inlet is arranged at the bottom of the fluidized bed lower cone, and the side wall jet air inlet is arranged on the side wall of the cone and the upper portion of the center hole. The organic silicon fluidized bed comprises a lower cone, a fluidized bed main body, an expansion section and a top upper sealing head. Chloromethane gas enters the cone from a center hole in the bottom and the injection pipe on the side wall and carries silicon powder particles to flow upwards to form spouted fluidization. And the silicon powder particles are taken out of the fluidized bed by the chloromethane gas from the top upper seal head to enter the cyclone separator. The fluidized bed is suitable for wide screening of silicon powder with particle size distribution, the problems that a distribution plate is blocked and a large amount of silicon powder is brought out are solved, abrasion of silicon powder particles to a heat exchange pipe is reduced, the surface updating of the silicon powder and the mixing efficiency of chloromethane gas and the silicon powder particles are improved, and therefore the monomer yield is increased, and online material pushing is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of gas inlet mode of no distribution plate and side spin gas inlet combination of fluidized bed for organic silicon monomer synthesis and organic silicon fluidized bed. BACKGROUND

[0002] The production of organic silicon material cannot be separated from methyl chlorosilane monomer, among which dimethyl dichlorosilane monomer (abbreviated as dimethyl) is the most important and largest amount of basic raw material. At present, the synthesis of organic silicon monomer in industrial production is mainly completed in a fluidized bed reactor. The performance of the fluidized bed has an important influence on the yield of organic silicon, monomer selectivity and conversion rate. Among them, the gas inlet device is the core component of the organic silicon monomer fluidized bed, which plays an important role in the quality of fluidization and stable operation in the fluidized bed. Large-scale organic silicon monomer fluidized bed generally uses a gas distribution plate with holes to fluidize the material, and the size of the orifice and the distance between the holes affect the pressure drop of the distributor and the quality of the fluidization of solid particles. The particle size of the reactant silicon powder used in industrial production is widely distributed, and the fluidization process is easy to produce particle segregation at different bed heights. Reasonable design of the structure of the distribution plate is crucial to ensure efficient fluidization of silicon powder and reduce particle segregation. Unreasonable design of the gas distribution plate will cause uneven gas distribution, form partial flow and channeling, and the gas holes are easy to leak and block, thereby reducing the gas-solid mass transfer rate, the heat released during the reaction is not removed in time, and the yield is affected by the increase of side reactions. In view of the above problems, CN216630756U discloses a two-layer combined gas injection device for organic silicon fluidized bed reactor, which improves the uniformity of gas distribution in the bed and promotes the update of the catalyst surface by breaking the silicon powder agglomeration. CN110559955A discloses an organic silicon fluidized bed gas distributor, which is uniformly distributed with radial gas inlet holes in the circumferential direction of the distribution plate, and the gas inlet holes are located at the lower end surface of the air cap, which can prevent material leakage. CN113877489A discloses a gas inlet device combined with middle gas inlet and side wall gas inlet, in which most of the chloromethane gas enters the middle gas inlet pipe to produce jet fluidization, and a small part of the chloromethane gas enters from the side wall gas inlet pipe. The above documents try to solve the problems of material leakage and uneven fluidization of the distribution plate by changing the structure of the distribution plate and the combination mode of the gas inlet. However, these gas distributors do not consider the influence of wide particle size distribution in the design process, and cannot solve the problems of particle segregation and large amount of carry-over. Therefore, reasonable design of the gas inlet device is of great significance to improve the fluidization quality in the fluidized bed and thus improve the monomer yield and ensure safe production. SUMMARY

[0003] The utility model aims at providing a kind of for organic silicon fluidized bed's air intake combination device and organic silicon fluidized bed.The air intake device and fluidized bed structure are reasonable, it is favorable to solve the problem of distribution board blockage, reduce the abrasion of silicon powder particle to heat exchange tube, improve the surface renewal of silicon powder and the mixing efficiency of chloromethane gas and silicon powder particle, to improve monomer yield and realize on-line pushing material.

[0004] The technical scheme of the present application provides a kind of for organic silicon fluidized bed's high-efficiency air intake combination device, the air intake combination device includes the combination air intake mode that bottom center air inlet and the spray device of lateral wall are arranged in the bottom of the cone component.

[0005] The center air inlet is cylindrical, and its diameter is 0.08-0.15 times the diameter of the upper part of the cone component, for realizing the entry of chloromethane gas. Chloromethane gas enters the fluidized bed reactor vertically from the center hole at a high speed, which can reduce the accumulation of silicon powder particles on the wall surface and the blockage of silicon powder particles in the center hole.

[0006] The spray device includes a ring pipe section, an inlet section and a spray pipe; the ring pipe section surrounds the outside of the cone component to provide a pressure environment and ensure that the raw chloromethane gas is ejected from the nozzle at a high gas velocity to form a rotating flow. The spray pipe extends into the inside of the cone component; the inlet section is fixed on the lateral wall of the cone between the ring pipe section and the spray pipe, and its diameter gradually decreases.

[0007] Several spray pipes are installed in the inlet section, with a length of 50-300 mm and a diameter of 5-20 mm.

[0008] The spray pipes are installed at the end of the inlet section at an angle of 30-50° away from the radial direction on the same cross section of the cone, to realize the upward flow of chloromethane gas in the fluidized bed in a rotating state.

[0009] The spray pipes are installed in the inlet section at an angle of 30-50° away from the radial direction on the same cross section of the cone and are inclined upward, to realize the upward flow of chloromethane gas in the fluidized bed in a rotating state.

[0010] The cone component is provided with symmetrically arranged silicon powder feeding ports and contact body return ports; and the silicon powder feeding ports and contact body return ports are arranged between the center air inlet and the spray device, to realize the entry of silicon powder and the entry of returned material.

[0011] Another object of the present application is to provide an organic silicon fluidized bed comprising the air intake combination device.

[0012] The upper part of the cone part is connected with the fluidized bed body through a flange and is fixed by bolts; the upper part of the fluidized bed body is provided with an enlarged section, and the diameter of the enlarged section is 1.2-1.5 times of the diameter of the fluidized bed body.

[0013] The upper part of the enlarged section is provided with an upper head, and the upper part of the upper head is provided with a material outlet.

[0014] The application also provides a preparation method of dimethyldichlorosilane monomer, which is prepared by the organic silicon fluidized bed.

[0015] The fresh silicon powder enters the cone part from the silicon powder feeding port and is mixed with the chloromethane gas from the bottom center gas inlet hole.

[0016] The flow ratio of the chloromethane gas entering from the bottom center gas inlet hole to the chloromethane gas entering from the injection device is 0.3-0.6; the speed of the chloromethane gas entering the cone part from the bottom center gas inlet hole is 3-10 m / s; and the speed of the chloromethane gas entering the cone part from the injection device is 150-300 m / s.

[0017] In some embodiments, the fresh silicon powder feeding port and the silicon powder return port are respectively arranged above the center hole of the cone side wall.

[0018] Advantages

[0019] The application aims to provide a high-efficiency air inlet combination device for an organic silicon fluidized bed.

[0020] The key points and protection points of the application.

[0021] The high-efficiency air inlet combination device and the organic silicon fluidized bed main body structure, the organic silicon fluidized bed can reduce the silicon powder particle accumulation of the wall surface area, ensure the uniform distribution of the silicon powder particles in the axial and radial directions, increase the particle circulation speed, and improve the monomer yield. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structure schematic diagram of the organic silicon fluidized bed.

[0023] Figure 2 It is a top view of the structure schematic diagram of the injection device.

[0024] Figure 3 Simplified cone component front view.

[0025] In the device, the bottom center air inlet hole 1, the fresh silicon powder feeding port 2, the contact body return port 3, the side wall injection air inlet 4, the lower vertebral body 5, the fluidized bed main body 6, the expansion section 7, the upper head 8, the material outlet 9, the annular tube section 10, the inlet section 11, and the injection pipe 12. DETAILED DESCRIPTION

[0026] In order to better understand the technical scheme of the utility model, the content of the utility model will be further described below in combination with examples, but the content of the application is not limited to the following examples.

[0027] Example 1

[0028] Referring to Figure 1 A high-efficiency air inlet combination device for an organic silicon fluidized bed, the air inlet combination device includes a combination air inlet mode in which a bottom center air inlet hole 1 is arranged at the bottom of a vertebral body component and an injection device 4 is arranged on the side wall.

[0029] The center air inlet hole 1 is in a cylindrical shape, the diameter of which is 0.12 times the diameter of the upper part of the cone component, for realizing the entry of chloromethane gas.

[0030] The injection device 4 includes an annular tube section 10, an inlet section 11, and an injection pipe 12; the annular tube section 10 is wrapped around the outside of the vertebral body component, for realizing the entry of chloromethane gas and providing a suitable pressure environment; the injection pipe 12 extends into the inside of the vertebral body component; the injection pipe 12 is fixed on the side wall of the cone between the annular tube section 10 and the inlet section 11, and the diameter gradually decreases.

[0031] A plurality of injection pipes 12 are installed in the inlet section 11, the length of the injection pipe 12 is 240 mm, and the diameter is 16 mm.

[0032] The injection pipe 12 is installed in the inlet section 11 at the same section of the cone, at an angle of 45° from the radial direction, for realizing the feeding of chloromethane gas in a rotating state and rising into the fluidized bed.

[0033] The silicon powder feeding port 2 and the contact body return port 3 are symmetrically arranged on the cone part, and are arranged between the central air inlet hole 1 and the injection device 4, for realizing the feeding of silicon powder and the return of the material.

[0034] Example 2

[0035] An organic silicon fluidized bed, wherein the air inlet combination device adopts the structure of Example 1. The upper part of the cone part in the air inlet combination device is connected to the fluidized bed body 6 through a flange, and is fixed by bolts; the upper part of the fluidized bed body 6 is provided with an enlarged section 7, and the diameter of the enlarged section 7 is 1.2 times the diameter of the fluidized bed body 6. The upper part of the enlarged section is provided with an upper head, and the upper part of the upper head is provided with a material outlet.

[0036] Example 3

[0037] A preparation method of dimethyldichlorosilane monomer, which is prepared by using the organic silicon fluidized bed of Example 2 for reaction, and the preparation steps are as follows:

[0038] Fresh silicon powder enters the cone part from the silicon powder feeding port 2, and is mixed with chloromethane gas from the bottom central air inlet hole 1, while chloromethane gas enters the cone part from the injection device 4. Under the conditions of reaction temperature (between 285-325℃) and pressure (between 0.15-0.35MPa), the chloromethane gas with silicon powder flows upwards in the cone part, forms a spouted fluidization into the fluidized bed, so that the chloromethane gas forms an upward and rotating state in the fluidized bed for reaction, and dimethyldichlorosilane monomer is prepared. Fresh silicon powder is supplemented into the fluidized bed reactor from the feeding port, unreacted silicon powder particles are taken out of the fluidized bed by chloromethane gas from the top of the upper head into the cyclone separator, and the silicon powder recovered from the cyclone separator reenters the bed from the return port.

[0039] The flow ratio of the amount of chloromethane gas entering from the bottom center air inlet hole 1 to the amount of chloromethane gas entering from the injection device 4 is 0.5; the velocity of chloromethane gas entering the cone part from the bottom center air inlet hole 1 is 10 m / s; and the velocity of chloromethane gas entering the cone part from the injection device 4 is 300 m / s. The technical scheme of the application can make the running process without the problem of blockage within 3 months, the accumulation amount of wall surface silicon powder is small, and the stable production of the material is not affected; the gas inlet mode combining the spouting and the side wall jet flow is adopted, the axial and radial mixing of the silicon powder particles is increased, the circulation amount of the silicon powder particles is improved, and then the reaction efficiency is improved, so that the chloromethane single-pass conversion rate can reach 55%, and the monomer space-time yield can reach 280 kg / t silicon powder.h.

Claims

1. A fluidized bed for the synthesis of organosilicon monomers, characterized in that it comprises: The combined air inlet device comprises a bottom center air inlet hole (1) arranged at the bottom of the cone part and a spray device (4) arranged at the sidewall.

2. The fluid bed for silicone monomer synthesis according to claim 1, wherein, The center air inlet hole (1) is in a cylindrical shape, and its diameter is 0.08-0.15 times the diameter of the upper part of the cone part, for realizing the inlet of chloromethane gas.

3. The fluid bed for silicone monomer synthesis according to claim 1, wherein, The spray device (4) comprises a ring pipe section (10), an inlet section (11) and a spray pipe (12); the ring pipe section (10) is arranged around the outside of the cone part, for realizing the inlet of chloromethane gas and providing a pressure environment; the spray pipe (12) extends into the inside of the cone part; the inlet section (11) is fixed on the sidewall of the cone part between the ring pipe section (10) and the spray pipe (12), and its diameter gradually decreases.

4. The fluid bed for silicone monomer synthesis according to claim 3, wherein A plurality of spray pipes (12) are arranged in the inlet section (11), and the length of the spray pipe (12) is 50-300 mm and the diameter is 5-20 mm.

5. The fluid bed for silicone monomer synthesis according to claim 4, wherein The spray pipes are arranged at the end of the inlet section (11) on the same cross section of the cone part, and are arranged at an angle of 30-50° to the radial direction, for realizing the upward flow of chloromethane gas in a rotating state in the fluidized bed.

6. The fluid bed for silicone monomer synthesis according to claim 1, wherein The cone part is also symmetrically provided with a silicon powder feeding port (2) and a contact body return port (3); and the silicon powder feeding port (2) and the contact body return port (3) are arranged between the center air inlet hole (1) and the spray device (4), for realizing the inlet of silicon powder and the inlet of contact body return.

7. A silicone fluidized bed characterized in that, The combined air inlet device of the fluidized bed for synthesizing organic silicon monomers comprises the fluidized bed of any one of claims 1-6.

8. The silicone fluidized bed of claim 7, wherein, The upper part of the cone part is connected to the fluidized bed body (6) through a flange, and is fixed by bolts; the upper part of the fluidized bed body (6) is provided with an enlarged section (7), and the diameter of the enlarged section (7) is 1.2-1.5 times the diameter of the fluidized bed body (6).

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