Organosilicon monomer synthesis aggregate and return system
By setting up multiple parallel cyclone separators and a fine powder tank alternating return system in the fluidized bed, the problems of high operating intensity and equipment wear in traditional silicone monomer production are solved, the continuous quantitative return of silicon powder to the bed and the adjustable cyclone separation are achieved, and the production stability and automation level are improved.
Patent Information
- Application Number
- CN202422636177.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-10-30
AI Technical Summary
In traditional fluidized bed production of organosilicon monomers, the aggregation and return operations are intensive, the equipment is subject to high wear and tear, and the cyclone separation efficiency cannot be adjusted, which affects production stability and the degree of automation.
Multiple parallel primary cyclone separators are set in the fluidized bed, and the cyclone outlets are merged outside the fluidized bed. Combined with the fine powder tank to alternately receive and return materials, a lined ceramic valve body and automated instrument control are used to achieve continuous quantitative return of silicon powder to the bed and adjustable separation of the secondary cyclone.
It reduces labor intensity, reduces heat loss, improves bed stability and reaction activity, extends production cycle, reduces equipment failure rate, and improves production automation and economic benefits.
Smart Images
Figure CN223366901U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a device for producing organic silicon monomers, in particular to an organic silicon monomer synthesis aggregate and recycling system, belonging to the technical field of organic silicon production. Background Art
[0002] Organosilicon materials are a new class of materials developed only in recent decades. They are primarily categorized into four main categories: silicone rubber, silicone oil, silane coupling agents, and silicone resins. They are widely used in industries such as aerospace, pharmaceutical engineering, and machinery manufacturing. Currently, industrial production of organosilicon monomers utilizes a direct synthesis process, involving a gas-solid phase reaction between methyl chloride and silicon powder within a fluidized bed reactor. The reaction products are separated and purified by cyclones, where most of the silicon powder is recovered. Domestic fluidized bed synthesis technology for organosilicon monomers generally utilizes an external multi-stage cyclone system with intermittent return of fine powder to the bed. Specifically, the first cyclone recovers fine powder, which is then discharged from a hopper to a fine powder tank. The silicon powder in the tank is then returned to the bed at regular intervals (5-30 minutes) through loss-in-weight metering. The second cyclone recovers fine powder, which is then discharged from a hopper to a fine powder tank. The silicon powder in the tank is then returned to the bed at regular intervals (20-60 minutes) through loss-in-weight metering. This process continues with the third and fourth cyclones, with the latter two cyclones either returning or discharging the collected ultrafine powder as needed.
[0003] In traditional aggregate and recycling processes, the primary cyclone typically recovers 80%-95% of the silicon powder carried over from the fluidized bed. This requires frequent and demanding recycling operations, resulting in significant fluctuations in bed control due to the intermittent return of large quantities of fine powder to the bed, high equipment wear and failure rates, and significant heat loss from the carryover of high-temperature fine powder. Furthermore, because cyclones are static devices, traditional technologies with a fixed cyclone type cannot adapt separation performance to changes in production load or feedstock, hindering automation and production stability. Summary of the Invention
[0004] The utility model aims to overcome the aggregation and return technology in the traditional fluidized bed production process of organic silicon monomers, reduce the operating intensity of workers and realize automation; solve the impact of large intermittent return volumes on the fluidized state and the wear of equipment; achieve controllable cyclone efficiency, ensure that harmful impurities are completely removed from the reaction system, and extend the operating cycle.
[0005] The solution of the utility model is:
[0006] An organic silicon monomer synthesis collection and recycling device, comprising a fluidized bed, a first-stage cyclone separator, a second-stage cyclone separator, a receiving hopper for the second-stage cyclone separator, a fine powder tank A, a fine powder tank B, a third-stage cyclone separator, a receiving hopper for the third-stage cyclone separator, a waste powder tank, connecting pipelines, and automated instrument valves;
[0007] The gas phase outlet at the top of the fluidized bed is connected to the inlet of the secondary cyclone separator;
[0008] The gas phase outlet of the secondary cyclone separator is connected to the inlet of the tertiary cyclone separator, and the solid phase outlet of the secondary cyclone separator is connected to the receiving hopper of the second-stage cyclone separator; the receiving hopper of the second-stage cyclone separator is connected to the inlets of fine powder tank A and fine powder tank B.
[0009] A first-stage cyclone separator is fixedly arranged inside the fluidized bed, and the top outlet of the first-stage cyclone separator is connected to the gas phase outlet at the top of the fluidized bed.
[0010] A material leg is provided at the bottom of the first-stage cyclone separator and extends into the lower middle part of the fluidized bed.
[0011] The first-stage cyclone separators are 2-4 in parallel, each cyclone is provided with an independent feed leg, and the outlets of the cyclone separators are equidistantly collected on a main pipe and selectively collected in the fluidized bed or outside the fluidized bed.
[0012] In some preferred cases, three parallel cyclone separators are arranged in the fluidized bed, and the outlets of the cyclone separators are combined outside the fluidized bed.
[0013] The fine powder tank A and the fine powder tank B are connected to the solid phase inlet at the bottom of the fluidized bed through pipelines respectively.
[0014] Fine powder tanks A and B alternately receive and return material, switched by automated valves. A nitrogen pressure line is installed above each tank. A ceramic-lined valve—a valve with no moving parts—is installed between the return line from the fine powder tank to the fluidized bed. The valve's top is connected to the fine powder tank pipeline, its middle to the gas booster line, and its bottom end to the gas booster line and the fluidized bed via a pipeline. During operation, the booster line, the flowmeter on the nitrogen pressure line, the regulating valve, and the pressure differential between the fine powder tank and the return line collaborate to achieve quantitative and continuous return of fine powder to the bed.
[0015] The gas phase outlet of the three-stage cyclone separator is a dehumidification dust removal system, the solid phase outlet of the three-stage cyclone separator is connected to the three-stage cyclone separator receiving hopper, and the three-stage cyclone separator receiving hopper is connected to the waste powder tank.
[0016] The fluidized bed is equipped with a heat transfer oil heat exchange pipe to maintain a constant reaction temperature. The diameter of the expanded section is 1-2 times that of the straight section, and the length is 0.3-0.8 times that of the straight section. The height of the straight section of the fluidized bed is not more than 10 meters.
[0017] A back-flushing system is set at the bottom ash hopper of the secondary cyclone separator. The reaction products pass through the secondary cyclone separator and then selectively go to the tertiary cyclone separator or the post-wet dust removal system.
[0018] Advantages of this utility model:
[0019] (1) Multiple cyclone separators are connected in parallel in the first stage. The main cyclone body is set in the fluidized bed, and the cyclone outlet is combined outside the fluidized bed, which reduces the processing cost of the fluidized bed. (2) The first stage cyclone aggregates are directly and evenly returned to the bed continuously, and the silicon powder collected by the second stage cyclone is continuously and quantitatively returned to the bed, which greatly reduces the labor intensity and reduces the heat loss of fine powder outside the bed. At the same time, it effectively improves the stability of the bed layer in the fluidized bed, and improves the reaction activity and selectivity. (3) This technology reduces the external wear of the device and reduces the equipment failure rate. Compared with traditional technology, the device investment is low and a large fine powder storage tank is not required. The inherent safety of the device is increased. (4) The efficiency of the second stage cyclone can be adjusted according to the reaction situation, which can better stabilize production, extend the production cycle, and improve the economic benefits of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a structural diagram of the device of the present invention, in which: 1. fluidized bed; 2. first-stage cyclone separator; 3. second-stage cyclone separator; 4. second-stage cyclone separator receiving hopper; 5. fine powder tank A; 6. fine powder tank B; 7. third-stage cyclone separator; 8. third-stage cyclone separator receiving hopper; 9. waste powder tank; 10. ceramic-lined valve body. The remaining automatic control instruments, valves and control logic are not shown one by one. Those skilled in the art can know that they can meet the automatic continuous collection and return of materials of this system. DETAILED DESCRIPTION
[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Each embodiment is intended only to illustrate the technical concept and features of the present invention. Its purpose is to enable those familiar with the art to understand the contents of the present invention and implement them accordingly. It is not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention shall be included within the scope of protection of the present invention.
[0022] Example 1
[0023] A collection and recycling system for synthesizing organic silicon monomers comprises a fluidized bed 1, a primary cyclone 2, a secondary cyclone 3, a secondary cyclone hopper 4, a fine powder tank A 5, a fine powder tank B 6, a tertiary cyclone 7, a tertiary cyclone hopper 8, a waste powder tank 9, and a ceramic-lined valve body 10. The gas phase outlet at the top of the fluidized bed 1 is connected to the inlet of the secondary cyclone 3; the gas phase outlet of the secondary cyclone 3 is connected to the tertiary cyclone 7, and the solid phase outlet is connected to the secondary cyclone hopper 4; the secondary cyclone hopper 4 is connected to the inlets of the fine powder tanks A 5 and B 6. A ceramic-lined valve body with no moving parts is installed between the return pipes from the fine powder tanks to the fluidized bed. The upper portion of the valve body is connected to the fine powder tank pipeline, the middle portion is connected to the gas booster pipeline, one end of the bottom portion is connected to the gas booster pipeline, and the other end is connected to the fluidized bed via a pipeline. During operation, the flow meter on the booster pipeline, nitrogen pressure pipeline, regulating valve, fine powder tank pressure, and return pipeline pressure difference cooperate to achieve quantitative and continuous return of fine powder to the bed.
[0024] The first-stage cyclone separator 2 is supported and fixed inside the fluidized bed 1, and its outlet is connected to the gas phase outlet at the top of the fluidized bed. A feed leg is set at the bottom of the first-stage cyclone separator 2, extending into the middle and lower part of the fluidized bed.
[0025] The fine powder tank A5 and the fine powder tank B6 are connected to the solid phase inlet at the bottom of the fluidized bed 1 through pipelines respectively.
[0026] The outlet of the secondary cyclone separator 3 is connected to the inlet of the tertiary cyclone separator 7, the gas phase outlet of the tertiary cyclone is a dehumidification dust removal system, the solid phase outlet of the tertiary cyclone is connected to the hopper 8 of the tertiary cyclone separator, and the hopper 8 of the tertiary cyclone separator is connected to the waste powder tank 9.
[0027] Each storage tank is equipped with a pressure gauge. A nitrogen line with flow control is installed above the fine powder tank, and a level gauge is also included. Fine powder tanks A5 and B6 alternately receive and return materials, switching between them using an automatic valve. The return line from the fine powder tank to the fluidized bed is equipped with a custom fitting, with gas booster lines and corresponding automatic instrumentation installed at the front and side ends of the custom fitting. The first-stage cyclone separator 2 consists of three units connected in parallel. Each cyclone has an independent feed leg, and the outlets of each cyclone are evenly spaced and connected to a single main pipe outside the fluidized bed. A backflush system is installed at the bottom hopper of the second-stage cyclone. After passing through the second-stage cyclone, the reaction products can be sent to the third-stage cyclone system or directly to the post-wet dust removal system.
[0028] Example 2
[0029] In the organosilicon monomer synthesis aggregate and recycling system composed of Example 1, methyl chloride and silicon powder react at a certain pressure and temperature in a fluidized bed. The reaction products, unreacted methyl chloride, and silicon powder enter the primary cyclone separator. 60-90% of the unreacted silicon powder is intercepted by the primary cyclone separator and returns to the dense phase section of the fluidized bed through its feed leg to re-react. Unintercepted fine powder enters the secondary cyclone separator with the gas phase for further separation. The secondary cyclone separator collects approximately 9-39% of the fine powder and enters the secondary cyclone receiving hopper, where the fine powder is alternately discharged into fine powder tank A and fine powder tank B. Fine powder tanks A and B alternately receive and discharge materials. While fine powder tank A is receiving material, fine powder tank B is disconnected from a rotary hopper. The top of fine powder tank B is pressurized to 0.35-0.55 MPa with nitrogen. The valve connecting the solid phase inlet pipeline at the bottom of the fine powder tank to the bottom of the fluidized bed is opened. By adjusting the flow rate of 100°C methyl chloride booster gas at the bottom and middle of the ceramic valve body on this pipeline, and controlling the pressure at the top of the fine powder tank and the pressure of the return pipeline, the fine powder in fine powder tank B is uniformly and continuously returned to the bed, and the return rate is adjustable. A small amount of ultrafine powder is carried by the outlet of the secondary cyclone separator and enters the tertiary cyclone separation system for further gas-solid separation. The separated ultrafine powder is returned to the bed or discharged as needed. In a fluidized bed reaction system with an annual output of 150,000 tons of organosilicon monomer, about 80% of the silicon powder is directly returned to the bed through the first-level cyclone, and about 15-20% of the silicon powder is recovered through the second-level cyclone. The return rate is about 10 tons / hour. The material is evenly and continuously returned to the bed, which has a good effect on the stability of the fluidized bed and the reaction.
Claims
1. A system for synthesizing and recycling organic silicon monomers, characterized in that: It includes a fluidized bed (1), a first-stage cyclone separator (2), a second-stage cyclone separator (3), a second-stage cyclone separator receiving hopper (4), a fine powder tank A (5), a fine powder tank B (6), a third-stage cyclone separator (7), a third-stage cyclone separator receiving hopper (8), a waste powder tank (9), connecting pipelines, and automated instrument valves; The gas phase outlet at the top of the fluidized bed (1) is connected to the inlet of the secondary cyclone separator (3); The gas phase outlet of the secondary cyclone separator (3) is connected to the inlet of the tertiary cyclone separator (7), and the solid phase outlet is connected to the receiving hopper (4) of the secondary cyclone separator; the receiving hopper (4) of the secondary cyclone separator is connected to the inlets of the fine powder tank A (5) and the fine powder tank B (6).
2. The organosilicon monomer synthesis aggregate and recycling system according to claim 1, characterized in that: The fine powder tank A (5) and the fine powder tank B (6) are connected to the solid phase inlet at the bottom of the fluidized bed (1) through pipelines respectively.
3. The organic silicon monomer synthesis aggregate and recycling system according to claim 2, characterized in that: Fine powder tank A (5) and fine powder tank B (6) are switched by automatic valves to realize alternating material receiving and returning; a nitrogen pressure pipeline is set on the top of each tank; a lined ceramic valve body (10) is set between the bottom of fine powder tank A (5) and fine powder tank B (6) and the return pipe of fluidized bed (1), the upper part of the lined ceramic valve body (10) is connected to the corresponding fine powder tank pipeline, the middle part is connected to the gas boost pipeline, one end of the bottom is connected to the gas boost pipeline, and the other end is connected to the fluidized bed through a pipeline.
4. The organosilicon monomer synthesis aggregate and recycling system according to claim 1, characterized in that: A first-stage cyclone separator (2) is fixedly arranged inside the fluidized bed (1), and a top outlet of the first-stage cyclone separator (2) is connected to a gas phase outlet at the top of the fluidized bed (1).
5. The organosilicon monomer synthesis aggregate and recycling system according to claim 4, characterized in that: A material leg is provided at the bottom of the first-stage cyclone separator (2) and extends into the lower middle portion of the fluidized bed.
6. The organosilicon monomer synthesis aggregate and recycling system according to claim 5, characterized in that: The first-stage cyclone separators (2) are 2-4 in parallel, and each cyclone is provided with an independent feed leg. The outlets of the cyclone separators are uniformly collected on a main pipe and selectively collected in the fluidized bed or outside the fluidized bed.
7. The organosilicon monomer synthesis aggregate and recycling system according to claim 6, characterized in that: Three parallel cyclone separators are arranged in the fluidized bed (1), and the outlets of the cyclone separators are collected outside the fluidized bed (1).
8. The organosilicon monomer synthesis aggregate and recycling system according to claim 6 or 7, characterized in that: The gas phase outlet of the three-stage cyclone separator (7) is a dehumidification dust removal system, the solid phase outlet of the three-stage cyclone separator (7) is connected to the three-stage cyclone separator receiving hopper (8), and the three-stage cyclone separator receiving hopper (8) is connected to the waste powder tank (9).
9. The organosilicon monomer synthesis aggregate and recycling system according to claim 1, characterized in that: The fluidized bed (1) is provided with a heat transfer oil heat exchange pipe to maintain a constant reaction temperature. The diameter of the expanded section is 1-2 times that of the straight section, and the length is 0.3-0.8 times that of the straight section. The height of the straight section of the fluidized bed is not more than 10 meters.
10. The organosilicon monomer synthesis aggregate and recycling system according to claim 1, characterized in that: A back-flushing system is provided at the bottom ash hopper of the secondary cyclone separator (3). After passing through the secondary cyclone separator (3), the reaction products are selectively sent to the tertiary cyclone separator (7) or to the post-wet dust removal system.