Trichlorosilane fluidized bed

Abstract

The present invention provides a trichlorosilane fluidized bed, which can reduce the accumulation of silicon powder on the heat exchange tube stabilizing plate, so that the silicon powder and hydrogen chloride can react more fully, thereby improving production efficiency. The fluidized bed shell includes a cylinder located in the middle of the fluidized bed shell, a discharge port located at the upper part of the fluidized bed shell, a silicon powder feed port and a hydrogen chloride air inlet located at the lower part of the fluidized bed shell, a heat exchange tube bundle is arranged in the cylinder, a stabilizing plate is installed on the heat exchange tube bundle, the stabilizing plate is in a cone shape with a high middle and low periphery, an auxiliary air inlet is arranged on the cylinder at a position corresponding to the stabilizing plate, and the extension line of the axis of the auxiliary air inlet is located on the stabilizing plate, which is used to make the air intake of the auxiliary air inlet blow toward the stabilizing plate.

Description

Technical Field

[0001] The invention relates to the technical field of fluidized beds, in particular to a trichlorosilane fluidized bed. Background Art

[0002] Trichlorosilane is an inorganic substance, mainly used in the synthesis of organosilanes and alkyl, aryl and organic functional group chlorosilanes. It is the most basic monomer in organosilane coupling agents and is also the raw material for the production of semiconductor silicon and single crystal silicon.

[0003] The common production method of trichlorosilane is to prepare trichlorosilane from hydrogen chloride and silicon powder. Mass production can be carried out through a fluidized bed. A common fluidized bed generally includes a carbon powder feed port and a hydrogen chloride feed port located at the bottom of the cylinder. The carbon powder is blown up in the cylinder by hydrogen chloride. Since a heat exchange tube is provided in the cylinder, hydrogen chloride and carbon powder react in a high temperature environment, and the generated trichlorosilane is discharged from the discharge port at the top of the fluidized bed. Since the fluidized bed is relatively long, in order to ensure sufficient reaction, the heat exchange tubes in the cylinder will also be correspondingly longer. In order to ensure the stability of the heat exchange tubes and avoid large-scale shaking caused by airflow, horizontal stabilizing plates are generally arranged at intervals on the heat exchange tubes. However, the setting of these stabilizing plates will cause a large amount of silicon powder to accumulate on these stabilizing plates, resulting in uneven mixing of hydrogen chloride and silicon powder and insufficient reaction, affecting production efficiency. Summary of the invention

[0004] In view of the problem that silicon powder is easily accumulated on a trichlorosilane fluidized bed and affects production efficiency, the present invention provides a trichlorosilane fluidized bed, which can reduce the accumulation of silicon powder on a heat exchange tube stabilizing plate, thereby enabling silicon powder and hydrogen chloride to react more fully, thereby improving production efficiency.

[0005] The technical scheme is as follows: a trichlorosilane fluidized bed, which includes a fluidized bed shell, the fluidized bed shell includes a cylinder located in the middle of the fluidized bed shell, a discharge port located at the upper part of the fluidized bed shell, a silicon powder feed port and a hydrogen chloride inlet located at the lower part of the fluidized bed shell, a heat exchange tube bundle is arranged in the cylinder, a stabilizing plate is installed on the heat exchange tube bundle, and the characteristic is that the stabilizing plate is in a cone shape with a high middle and low circumference, an auxiliary air inlet is arranged on the cylinder at a position corresponding to the stabilizing plate, and the extension line of the axis of the auxiliary air inlet is located on the stabilizing plate, so as to make the air intake of the auxiliary air inlet blow toward the stabilizing plate.

[0006] It is further characterized by:

[0007] The fluidized bed shell further comprises an upper end cap located above the cylinder and a lower end cap located below the cylinder. The cylinder comprises a heat exchange tube assembly section, a reaction section, and an air inlet distribution section arranged in sequence from top to bottom. The upper portion of the heat exchange tube assembly section is connected to the upper end cap, and the lower portion of the air inlet distribution section is connected to the lower end cap. An air inlet distribution plate is arranged in the air inlet distribution section. The air inlet distribution plate is in a cone shape with high circumference and low middle. The silicon powder feed port is connected to the air inlet distribution plate and communicated with the reaction section through an extension pipeline. A wind cap is connected to the air inlet distribution plate. The hydrogen chloride air inlet is communicated with the air inlet distribution section. The air inlet distribution section is communicated with the reaction section through the wind cap.

[0008] A packing gland is provided at the end of the extension pipe, a connecting piece 1 is provided in the middle of the air inlet distribution plate, the packing gland includes a connecting part 1 extending in the horizontal direction and a sealing part extending downward, the connecting piece 1 includes a connecting part 2 bolted to the connecting part 1 and a avoidance hole located in the middle thereof for the extension pipe to pass through, when the packing gland is connected to the air inlet distribution plate, a sealing gap is left between the extension pipe and the connecting part 2, an asbestos packing is provided in the sealing gap, and the bottom end of the sealing part extends into the sealing gap and is pressed on the packing;

[0009] A flange 1 is provided on the outer side of the bottom end of the cylinder of the heat exchange tube assembly section, a flange 2 is provided on the outer side of the top end of the cylinder of the reaction section, a flange 3 is provided on the outer side of the bottom end of the cylinder of the reaction section, a flange 4 is provided on the outer side of the top end of the cylinder of the air intake distribution section, and the flange 1 and the flange 2, and the flange 3 and the flange 4 are respectively connected by bolts; a protrusion 1 extending downward is provided at the bottom of the flange 1, a groove 1 is provided at the top of the flange 2 corresponding to the position of the protrusion 1, a flexible graphite winding pad is provided in the groove 1, and the protrusion 1 is sealed by pressing on the flexible graphite winding pad; the flange 3 and the flange 4 are respectively provided with opposite grooves 2 and 3, and a mounting block is connected to the end of the air intake distribution plate, the mounting block is located between the groove 2 and the groove 3, and flexible graphite winding pads are respectively provided between the mounting block and the bottoms of the grooves 2 and 3;

[0010] An assembly rod is provided in the heat exchange tube assembly section, a clamping bracket is provided on the upper part of the heat exchange tube, and the assembly rod is connected to the heat exchange tube and the clamping bracket through a suspension rod;

[0011] The reaction section is provided with a ring seat, a heating coil is provided on the outer side of the cylinder of the reaction section at a position corresponding to the position where the ring seat is not provided, a heating shell is provided on the outer side of the cylinder of the reaction section at a position corresponding to the position where the ring seat is provided, the heating shell and the cylinder of the reaction section are enclosed to form a heating chamber, a heat transfer oil inlet connected to the heating chamber is provided at the lower end of the heating shell, and a heat transfer oil outlet connected to the heating chamber is provided at the upper end, and the ring seat is connected to the outer side of the heating shell;

[0012] The outer side of the cylinder of the reaction section corresponding to the portion located in the heating chamber is connected with heat-conducting fins;

[0013] The bottom of the heating shell is also provided with a drain port, and the top of the heating shell is also provided with an exhaust port;

[0014] The heat exchange tube assembly section is also provided with a second heat transfer oil inlet and a second heat transfer oil outlet connected to the heat exchange tube;

[0015] The heat exchange tube assembly section, the reaction section, and the air intake distribution section are evenly provided with temperature measuring ports and pressure measuring ports.

[0016] The beneficial effects of the present invention are as follows: by making the stabilizing plate into a cone shape that is high in the middle and low around, a portion of the accumulated silicon powder falls under the action of gravity, thereby reducing accumulation; at the same time, an auxiliary air inlet is provided at the stabilizing plate, and air is blown toward the stabilizing plate through the auxiliary air inlet to blow away the remaining accumulated silicon powder, thereby effectively utilizing the silicon powder and ensuring production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of the present invention;

[0018] Figure 2 for Figure 1 The structural diagram of point A (the connection between the extension pipe and the air inlet distribution plate);

[0019] Figure 3 for Figure 1 The structural diagram of point B (the connection between the heat exchange tube assembly section and the reaction section);

[0020] Figure 4 for Figure 1 The structural diagram of point C (the connection between the reaction section and the intake distribution section);

[0021] Figure 5 for Figure 1 The D section (heat exchange tube assembly section) and the upper head enlarged structure diagram;

[0022] Figure 6 for Figure 1 Structural diagram of point G (ring seat installation point). DETAILED DESCRIPTION

[0023] like Figure 1 The trichlorosilane fluidized bed shown comprises a fluidized bed shell, which comprises a cylinder located in the middle of the fluidized bed shell, a discharge port 1 located at the upper part of the fluidized bed shell, a silicon powder feed port 2 located at the lower part of the fluidized bed shell, and a hydrogen chloride air inlet 3. A heat exchange tube bundle 4 is arranged in the cylinder, and a stabilizing plate 5 (the stabilizing plate is in cross-section in the figure) is installed on the heat exchange tube bundle 4. The stabilizing plate 5 is in a conical shape with a high middle and low surroundings. An auxiliary air inlet 6 is arranged at a position corresponding to the stabilizing plate on the cylinder, and the extension line of the axis of the auxiliary air inlet 6 is located on the stabilizing plate 5, so that the air intake of the auxiliary air inlet 6 is blown toward the stabilizing plate 5.

[0024] Through the above structure, silicon powder and hydrogen chloride enter from the bottom of the fluidized bed and move upward, and the heat exchange tube can provide sufficient reaction temperature to make the silicon powder and hydrogen chloride react. Since the length of the entire shell is relatively long, which can reach more than 14,000 mm, the heat exchange tube also has a correspondingly long length. In order to avoid violent shaking under wind speed, the heat exchange tube is passed through a stabilizing plate fixed on the inner wall of the shell or a stabilizing plate is clamped on the heat exchange tube bundle to reduce the degree of shaking. The stabilizing plate is designed to be conical to reduce the accumulation of silicon powder. At the same time, the accumulation of silicon powder can be further reduced by setting an auxiliary air inlet to blow away the silicon powder. The auxiliary air inlet can be set to open at a frequency or open throughout the whole process as needed.

[0025] Specifically, the fluidized bed shell further comprises an upper head 7 located above the cylinder and a lower head 8 located below the cylinder. A manhole 9 is provided on the lower head 8. The cylinder comprises a heat exchange tube assembly section D, a reaction section E, and an air inlet distribution section F arranged in sequence from top to bottom. The upper part of the heat exchange tube assembly section D is connected to the upper head 7, and the lower part of the air inlet distribution section F is connected to the lower head 8. An air inlet distribution plate 10 is arranged in the air inlet distribution section F. The air inlet distribution plate 10 is in a cone shape with a high periphery and a low middle. The silicon powder feed port 2 is connected to the reaction section E, and the reaction section E is connected to the air inlet distribution section F. It is connected to the air inlet distribution plate 10 and communicated with the reaction section E. A wind cap (not shown in the figure) is connected to the air inlet distribution plate 10. The hydrogen chloride air inlet 3 is communicated with the air inlet distribution section F. The air inlet distribution section F is communicated with the reaction section E through the wind cap. The inclined air inlet distribution plate 10 can increase its length so that more wind caps can be distributed, increase the air intake amount and make the air intake distribution more uniform. The silicon powder is directly discharged into the reaction section through the extension pipe 11, and the air enters the air inlet distribution section F and then enters the reaction section through the wind cap.

[0026] Combination Figure 2As shown, a packing gland 111 is provided at the end of the extension pipe 11, and a connecting piece 101 is provided in the middle of the air intake distribution plate 10. The packing gland 111 includes a connecting part 112 extending in the horizontal direction and a sealing part 113 extending downward. The connecting piece 101 includes a connecting part 102 bolted to the connecting part 112 and a avoidance hole located in the middle for the extension pipe 10 to pass through. When the packing gland 111 is connected to the air intake distribution plate 10, a sealing gap is left between the extension pipe 10 and the connecting part 102. An asbestos packing 12 is provided in the sealing gap. The bottom end of the sealing part 113 extends into the sealing gap and is pressed on the packing 12, thereby ensuring the sealing of the connection.

[0027] Combination Figure 3 , Figure 4 , Figure 5 As shown, a flange 131 is provided on the outer side of the bottom end of the cylinder of the heat exchange tube assembly section D, a flange 2 132 is provided on the outer side of the top end of the cylinder of the reaction section E, a flange 3 133 is provided on the outer side of the bottom end of the cylinder of the reaction section E, and a flange 4 134 is provided on the outer side of the top end of the cylinder of the air inlet distribution section F. The flange 131 and the flange 2 132, and the flange 3 133 and the flange 4 134 are respectively connected by bolts; a protrusion 1311 extending downward is provided at the bottom of the flange 131, and the top of the flange 2 132 corresponds to the position of the protrusion 1311. A groove one is provided, in which a flexible graphite winding pad 1321 is provided, and a protrusion one 1311 is sealed by pressing on the flexible graphite winding pad 1321; a corresponding groove two and a groove three are provided on the flange three 133 and the flange four 134 respectively, and a mounting block 103 is welded at the end of the air intake distribution plate 10, and the mounting block 103 is located between the groove two and the groove three, and flexible graphite winding pads are provided between the mounting block and the bottom of the groove two and the groove three respectively; the above structure can ensure the sealing of the connection and facilitate installation.

[0028] like Figure 1 , Figure 5 As shown, an assembly rod 14 is provided in the heat exchange tube assembly section D, a clamping bracket 16 is provided on the upper part of the heat exchange tube, and the assembly rod 14 is connected to the heat exchange tube and the clamping bracket 16 through a suspension rod 15. The heat exchange tube bundle is hoisted in the cylinder by the above structure, and a heat transfer oil inlet 401 and a heat transfer oil outlet 402 connected to the heat exchange tube are also provided on the heat exchange tube assembly section D. The heat exchange tube assembly section D, the reaction section E, and the air inlet distribution section F are evenly provided with temperature measuring ports 21 and pressure measuring ports 22.

[0029] Combination Figure 1 , Figure 6In order to increase the strength of the cylinder, the reaction section E is provided with a ring seat 17. At the same time, in order to ensure that the temperature inside the cylinder is sufficient and avoid insufficient temperature near the shell, a heating coil 18 is provided on the outer side of the cylinder of the reaction section E corresponding to the position where the ring seat is not provided. Due to the setting of the ring seat, the coil cannot be installed. Therefore, a heating shell 19 is provided on the outer side of the cylinder of the reaction section E corresponding to the position where the ring seat 17 is provided. The heating shell 19 and the cylinder of the reaction section E enclose a heating chamber 20. The lower end of the heating shell 19 is provided with a heat transfer oil inlet 191 connected to the heating chamber and the upper end is provided with a heat transfer oil outlet 192 connected to the heating chamber. The ring seat 17 is connected to the outer side of the heating shell 19, so that the temperature at the installation shell can be ensured to be sufficient. The bottom of the heating shell 19 is also provided with a drain port 194, and the top of the heating shell is also provided with an exhaust port 195, so that the material in the heating chamber can be discharged as needed; at the same time, in order to further ensure the temperature, the outer side of the cylinder of the reaction section corresponding to the part located in the heating chamber is connected with a heat transfer fin 193.

[0030] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by anyone familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A trichlorosilane fluidized bed, comprising a fluidized bed shell, wherein the fluidized bed shell comprises a cylinder located in the middle of the fluidized bed shell, a discharge port located at the upper part of the fluidized bed shell, a silicon powder feed port and a hydrogen chloride inlet located at the lower part of the fluidized bed shell, a heat exchange tube bundle is arranged in the cylinder, and a stabilizing plate is installed on the heat exchange tube bundle, characterized in that: The stabilizing plate is in a cone shape with a high middle and low circumference. An auxiliary air inlet is provided on the cylinder at a position corresponding to the stabilizing plate. The extended line of the axis of the auxiliary air inlet is located on the stabilizing plate, so that the air from the auxiliary air inlet is blown toward the stabilizing plate. The fluidized bed shell further comprises an upper end cap located above the cylinder and a lower end cap located below the cylinder. The cylinder comprises a heat exchange tube assembly section, a reaction section, and an air inlet distribution section arranged in sequence from top to bottom. The upper portion of the heat exchange tube assembly section is connected to the upper end cap, and the lower portion of the air inlet distribution section is connected to the lower end cap. An air inlet distribution plate is arranged in the air inlet distribution section. The air inlet distribution plate is in a cone shape with high circumference and low middle. The silicon powder feed port is connected to the air inlet distribution plate and communicated with the reaction section through an extension pipeline. A wind cap is connected to the air inlet distribution plate. The hydrogen chloride air inlet is communicated with the air inlet distribution section. The air inlet distribution section is communicated with the reaction section through the wind cap. A packing gland is provided at the end of the extension pipe, a connecting piece 1 is provided in the middle of the air inlet distribution plate, the packing gland includes a connecting part 1 extending in the horizontal direction and a sealing part extending downward, the connecting piece 1 includes a connecting part 2 bolted to the connecting part 1 and a avoidance hole located in the middle thereof for the extension pipe to pass through, when the packing gland is connected to the air inlet distribution plate, a sealing gap is left between the extension pipe and the connecting part 2, an asbestos packing is provided in the sealing gap, and the bottom end of the sealing part extends into the sealing gap and is pressed on the packing; An assembly rod is arranged in the heat exchange tube assembly section, a clamping bracket is arranged on the upper part of the heat exchange tube, and the assembly rod is connected with the heat exchange tube and the clamping bracket through a suspension rod.

2. The trichlorosilane fluidized bed according to claim 1, characterized in that: A flange one is provided on the outer side of the bottom end of the cylinder of the heat exchange tube assembly section, a flange two is provided on the outer side of the top end of the cylinder of the reaction section, a flange three is provided on the outer side of the bottom end of the cylinder of the reaction section, a flange four is provided on the outer side of the top end of the cylinder of the air intake distribution section, and the flange one and the flange two, and the flange three and the flange four are respectively connected by bolts; a protrusion one extending downward is provided at the bottom of the flange one, a groove one is provided at the top of the flange two corresponding to the position of the protrusion one, a flexible graphite winding pad is provided in the groove one, and the protrusion one is sealed by pressing on the flexible graphite winding pad; a groove two and a groove three are respectively provided on the flange three and the flange four, and a mounting block is connected to the end of the air intake distribution plate, the mounting block is located between the groove two and the groove three, and flexible graphite winding pads are respectively provided between the mounting block and the bottoms of the grooves two and three.

3. The trichlorosilane fluidized bed according to claim 1, characterized in that: The reaction section is provided with a ring seat, a heating coil is provided at a position on the outside of the cylinder of the reaction section corresponding to the position where the ring seat is not provided, a heating shell is provided on the outside of the cylinder of the reaction section corresponding to the position where the ring seat is provided, the heating shell and the cylinder of the reaction section are enclosed to form a heating chamber, a heat transfer oil inlet connected to the heating chamber is provided at the lower end of the heating shell, and a heat transfer oil outlet connected to the heating chamber is provided at the upper end, and the ring seat is connected to the outside of the heating shell.

4. The trichlorosilane fluidized bed according to claim 3, characterized in that: The outer side of the cylinder of the reaction section corresponding to the portion located in the heating chamber is connected with heat-conducting fins.

5. The trichlorosilane fluidized bed according to claim 3 or 4, characterized in that: The bottom of the heating shell is also provided with a drain port, and the top of the heating shell is also provided with an exhaust port.

6. The trichlorosilane fluidized bed according to claim 1, characterized in that: The heat exchange tube assembly section is also provided with a second heat transfer oil inlet and a second heat transfer oil outlet connected to the heat exchange tube.

7. The trichlorosilane fluidized bed according to claim 1, characterized in that: The heat exchange tube assembly section, the reaction section, and the air intake distribution section are evenly provided with temperature measuring ports and pressure measuring ports.

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