A novel tubular reactor apparatus for the production of disilane

Abstract

A novel tubular reactor device for producing ethylsilane comprises a tubular reactor, which is of a split structure and comprises an upper cover, a barrel and a lower cover which are detachably and sealingly connected from top to bottom, and has a feeding port and a discharging port, the feeding port is sequentially communicated with a material mixer and a material preheater which are located outside the tubular reactor, and a rotary flow gas distributor is connected to the lower side of the inner side of the feeding port through a connecting pipe; the rotary flow gas distributor is detachably connected to the upper part of the barrel through a support frame, and the upper end of the support frame is clamped to the inner side of the connection between the upper cover and the upper end surface of the barrel. The novel device strengthens the rotation of mixed gas, avoids the generation of silicon powder due to long-time heating of silane, improves the conversion rate of silane, and designs the rotary flow gas distributor as a spiral pipe, so that the mixed gas can be more uniformly distributed in the reactor, the heating is uniform, the temperature rising speed is fast, the temperature rising time is further saved, and the yield of ethylsilane is improved.

Description

Technical Field

[0001] This utility model relates to the field of tubular reactor technology, specifically a novel tubular reactor device for producing silane. Background Technology

[0002] Currently, traditional silane reactors are packed reactors, filled with packing material. Although the packing increases the specific surface area and mass transfer and heat exchange efficiency, slows down the flow rate of the reactants, and prolongs the contact time of the reactants, making the reaction more complete, the packing layer of existing packed reactors is relatively dense, which can easily lead to clogging, and easily leave dirt and solids, affecting efficiency. Regular cleaning and maintenance are required to maintain its performance.

[0003] The characteristic of the silane reaction is high-temperature pyrolysis to generate active free radicals, which further combine to form silane. Reaching the pyrolysis temperature is crucial, and the heating time must be carefully controlled to avoid silicon powder precipitation due to excessive heating, which would negatively impact efficiency. During the silane reaction, a large amount of solid silicon powder is precipitated. Packed reactors, with their small mesh size and large silicon powder particle size, are prone to agglomeration and clogging of the packing material. Current packed reactors cannot meet the production requirements of silane. Utility Model Content

[0004] To address the technical problems existing in the background art, this utility model provides a novel tubular reactor device for producing silane.

[0005] The technical solution of this utility model is as follows:

[0006] A novel tubular reactor device for producing silane includes a tubular reactor with a split structure, comprising a detachable and sealed upper cover, a cylindrical body, and a lower cover connected from top to bottom. The tubular reactor has an inlet and an outlet. A material mixer and a material preheater are sequentially connected to the inlet and located outside the tubular reactor. A rotary flow gas distributor is connected to the lower inner side of the inlet via a connecting pipe. The inlet of the rotary flow gas distributor is connected to the outlet of the mixer.

[0007] The rotary flow gas distributor is detachably connected to the upper part of the cylinder via a support frame, with the upper end of the support frame clamped inside the connection between the top cover and the upper end face of the cylinder.

[0008] To facilitate the discharge of silicon powder accumulated inside the tubular reactor and prevent the outlet of the tubular reactor from being blocked by silicon powder, a purge port with a valve is provided on one side of the outlet. The purge port is set at an angle downward. When it is necessary to clean the tubular reactor, the outlet is first blocked, and then nitrogen gas for cleaning is introduced from the inlet of the tubular reactor. The nitrogen gas is delivered to the tubular reactor through a rotary flow gas distributor, and the silicon powder accumulated inside the tubular reactor is discharged through the purge port.

[0009] The feed inlet of the tubular reactor is fed with a preheated and mixed mixture of ammonia and silane. To enhance the rotation of the mixed gas, avoid prolonged heating of silane to prevent the precipitation of silicon powder, and improve the silane conversion rate, a spiral flow gas distributor is designed as a spiral tube. The spiral tube includes a first spiral tube and a second spiral tube connected vertically. The outer diameter of the upper part of the second spiral tube is the same as the outer diameter of the lower part of the first spiral tube. The outer diameter of the second spiral tube decreases from top to bottom. The spiral tube can distribute the mixed gas more evenly inside the reactor, making it heat evenly and rapidly, further saving heating time and improving the yield of silane.

[0010] Furthermore, the pitch of the first helical tube decreases from top to bottom, while the diameter of the first helical tube remains unchanged. By using a helical path with a fixed diameter, the gas can form a stable swirling flow, enhancing radial mixing. By setting the pitch to decrease, the rotation intensity of the mixed gas can be further enhanced.

[0011] To facilitate uniform diffusion of the mixer across the entire cross-section of the reactor, the outlet of the second spiral tube is a gradually expanding outlet.

[0012] Another structure of the rotary flow gas distributor is that the rotary flow gas distributor is a vortex tube arranged in the radial direction of the cylinder. The vortex tube has multiple downward-facing first gas holes, which facilitates the rotary flow gas distributor to deliver the mixer to multiple positions in the cross section of the tubular reactor.

[0013] The tubular reactor has a diameter of 0.1-0.25m. Compared with the existing packed reactor, the diameter of the tubular reactor is smaller, which is beneficial to improve the uniformity of distribution, the reaction rate of materials, and the conversion rate.

[0014] The length-to-diameter ratio of a tubular reactor is 30:1-50:1, while that of a packed reactor is 20:1-30:1. Compared to the size of existing packed reactors, tubular reactors can extend the material residence time, ensuring full reaction and higher silane conversion rate. The higher the length-to-diameter ratio, the larger the heat transfer area per unit volume, the higher the heat exchange efficiency, and the faster the heating rate.

[0015] To ensure that more than 90% of the reactor space is used for the core reaction, the vertical length of the rotary flow gas distributor is less than 1 / 10 of the reactor length. The gas only stays in the distributor briefly and quickly enters the main reaction zone, reducing side reactions such as premature precipitation of silicon powder.

[0016] The support frame is a ring frame, and multiple support arms are detachably connected to the ring frame and distributed vertically. The support arms are connected to the tube body of the corresponding spiral tube. The support arms can support the first spiral tube and the second spiral tube respectively to prevent the first spiral tube and the second spiral tube from shaking.

[0017] The beneficial effects of this utility model are as follows:

[0018] The existing packed reactor can be replaced with a hollow tubular reactor to avoid the packing layer being blocked by silicon powder precipitation, which would affect efficiency and pose safety hazards. The space velocity ratio of the packed reactor is relatively high and difficult to control. Removing the packing can reduce the space velocity ratio and reduce the difficulty of operation.

[0019] Removing the packing layer from existing packed reactors reduces construction costs, saves investment and expenses, and avoids the costs of repairing or replacing the packing layer due to blockage. In tubular reactors, the silicon powder solids precipitated by heating silane will no longer block the packing layer, affecting efficiency and causing safety hazards.

[0020] The tubular reactor is a split reactor, which makes it easy to install the rotating gas distributor on its inner upper part. The rotating gas is connected to the rotating gas distributor through the support frame. To facilitate the installation of the support frame, the upper outer part of the support frame is directly installed at the connection between the top cover and the cylinder, without the need to drill holes separately in the cylinder to install the support frame.

[0021] The feed inlet of the tubular reactor is fed with a mixture of preheated and mixed ammonia and silane. To enhance the rotation of the mixed gas, avoid prolonged heating of silane to prevent the precipitation of silicon powder, and improve the silane conversion rate, the rotating flow gas distributor is designed as a spiral tube. The spiral tube can distribute the mixed gas more evenly inside the reactor, making it heat evenly and heating up quickly, further saving heating time and improving the yield of silane.

[0022] To facilitate the discharge of silicon powder accumulated inside the tubular reactor and prevent the outlet of the tubular reactor from being blocked by silicon powder, a purge port with a valve is provided on one side of the outlet. The purge port is set at an angle downward. When it is necessary to clean the tubular reactor, the outlet is first blocked, and then nitrogen gas for cleaning is introduced from the inlet of the tubular reactor. The nitrogen gas is delivered to the tubular reactor through a rotary flow gas distributor, and the silicon powder accumulated inside the tubular reactor is discharged through the purge port. Attached Figure Description

[0023] In the attached diagram:

[0024] Figure 1 A cross-sectional schematic diagram of a rotating flow gas distributor consisting of a spiral tube;

[0025] Figure 2 for Figure 1 Enlarged structural diagram at point A in the middle;

[0026] Figure 3 This is a partial front view;

[0027] Figure 4 A schematic diagram of the supporting frame and helical tube structure;

[0028] Figure 5 This is a schematic diagram of a spiral tube structure;

[0029] Figure 6 A schematic diagram of a vortex tube structure for a rotary flow gas distributor;

[0030] Figure 7 This is a schematic diagram of a vortex tube structure;

[0031] The components represented by the various reference numerals in the diagram are:

[0032] 1. Tubular reactor; 101. Top cover; 102. Shell; 1021. Annular trough; 103. Bottom cover; 104. Inlet; 105. Outlet; 2. Material mixer; 3. Material preheater; 4. Connecting pipe; 5. Rotary flow gas distributor; 6. First spiral tube; 7. Second spiral tube; 701. Gradually expanding outlet; 8. Vortex tube; 801. First vent; 9. Support frame; 901. Connecting annular platform; 10. Support arm; 1001. Arc-shaped support surface; 1002. Connector; 11. Purge port. Detailed Implementation

[0033] Example 1:

[0034] See Figure 1 , Figure 2 and Figure 3 As shown, a novel tubular reactor device for producing silane includes a tubular reactor 1, which is formed by modifying an existing packed reactor by removing the packing material and replacing it with a hollow tubular reactor 1. The tubular reactor 1 has a split structure, including a detachable and sealed upper cover 101, a cylindrical body 102, and a lower cover 103 connected from top to bottom. The tubular reactor 1 has an inlet 104 and an outlet 105. A material mixer 2 and a material preheater 3 located outside the tubular reactor 1 are sequentially connected to the inlet 104. A rotary flow gas distributor 5 is connected to the lower inner side of the inlet 104 through a connecting pipe 4. The inlet of the rotary flow gas distributor 5 is connected to the outlet of the mixer.

[0035] The existing packed reactor can be replaced with a hollow tubular reactor to avoid the blockage of the packing layer due to silicon powder precipitation, which would affect efficiency and pose safety hazards. The space velocity of the packed reactor is relatively high and difficult to control. Removing the packing can reduce the space velocity ratio and reduce the difficulty of operation. It can also simplify the reactor, optimize the structure, and save investment costs.

[0036] The original packed reactor had a low or ambient temperature at the inlet. Silane stored in the tank area was discharged via pipeline, and hydrogen was discharged via hydrogen pipeline. In this embodiment, hydrogen and silane are metered and then enter the material preheater 3 for preheating. The silane preheating raises the temperature to 320-380°C, and the hydrogen preheating raises the temperature to 450-550°C. Then, the two are thoroughly mixed in the material mixer 2. The temperature of the mixed material (silane and hydrogen) can instantly reach 380-430°C, and then it is heated to 450-480°C in the tubular reactor 1, where it is decomposed to generate free radical molecules, which combine to form silane. The heating time is short, the decomposition efficiency is high, the number of free radical molecules increases, and the amount of silicon powder precipitated is reduced. This embodiment saves more than 70% of the heating time of the mixed gas and more than 30-60% of the electricity; the amount of solid silicon powder is reduced by more than 30%, greatly reducing the silicon powder precipitation rate and further improving the conversion rate of silane.

[0037] See Figure 2 , Figure 4 and Figure 5 As shown, the rotary flow gas distributor 5 is detachably connected to the upper part of the cylinder 102 via a support frame 9. The upper end of the support frame 9 is clamped inside the connection between the upper cover 101 and the upper end face of the cylinder 102. The support frame 9 is an annular frame, on which multiple support arms 10 are detachably connected, arranged vertically. Each support arm 10 is connected to the body of a corresponding spiral tube, and the support arm 10 can support the first spiral tube 6 and the second spiral tube 7 respectively, preventing the first spiral tube 6 and the second spiral tube 7 from shaking. One end of the support arm 10 is detachably connected to the annular frame via a connector 1002, and the upper end face of the other end is provided with an arc-shaped support surface 1001 for supporting the tube body. Multiple support arms 10 are provided, arranged on the upper part and along the rotation direction of the spiral tube, to support the spiral tube and prevent large shaking of the spiral tube.

[0038] It should be noted that the upper end of the support frame 9 is provided with a connecting annular platform 901, and the upper part of the inner wall of the cylinder 102 is provided with an annular groove 1021. The annular groove 1021 communicates with the upper end face of the cylinder 102. The connecting annular platform 901 is adapted to the annular groove 1021. The connecting annular platform 901 is installed in the annular groove 1021. The upper end face of the connecting annular platform 901 is flush with the upper end face of the cylinder 102. When the upper cover 101 is fixedly connected to the cylinder 102, the upper cover 101 can press on the upper end face of the connecting annular platform 901, thereby pressing the connecting annular platform 901, realizing the installation and fixation of the connecting annular platform 901 in the cylinder 102. This facilitates the simultaneous disassembly and maintenance of the connecting annular platform 901 and the spiral tube. Alternatively, the connecting annular platform 901 and the spiral tube can be installed and fixed on the outside of the cylinder 102 through the support arm 10, and then the connecting annular platform 901 and the spiral tube can be installed in the cylinder 102 at the same time.

[0039] To facilitate the discharge of silicon powder accumulated inside the tubular reactor 1 and prevent the outlet 105 of the tubular reactor 1 from being blocked by silicon powder, a purge port 11 with a valve is provided on one side of the outlet 105. The purge port 11 is set at an angle downward. When it is necessary to clean the tubular reactor 1, the outlet 105 is first blocked, and then nitrogen gas for cleaning is introduced from the inlet 104 of the tubular reactor 1. The nitrogen gas passes through the rotary flow gas distributor 5 into the tubular reactor 1, and the silicon powder accumulated inside the tubular reactor 1 is discharged through the purge port 11.

[0040] See Figure 1 , Figure 2 and Figure 4 As shown, the inlet 104 of the tubular reactor 1 is supplied with a preheated and mixed mixture of ammonia and silane. To enhance the rotation of the mixed gas, prevent the precipitation of silicon powder due to prolonged heating of silane, and improve the silane conversion rate, the rotating flow gas distributor 5 is designed as a spiral tube. The spiral tube includes a first spiral tube 6 and a second spiral tube 7 connected vertically. The outer diameter of the upper part of the second spiral tube 7 is the same as the outer diameter of the lower part of the first spiral tube 6. The outer diameter of the second spiral tube 7 decreases from top to bottom. The spiral tube can distribute the mixed gas more evenly inside the reactor, making it heat evenly and rapidly, further saving heating time and improving the yield of silane. To facilitate uniform diffusion of the mixer across the entire cross-section of the reactor, the outlet of the second spiral tube 7 is a gradually expanding outlet 701.

[0041] The pitch of the first helical tube 6 decreases from top to bottom, while the diameter of the first helical tube 6 remains constant. By using a helical path with a fixed diameter, the gas can form a stable swirling flow, enhancing radial mixing. By setting the pitch to decrease, the rotation intensity of the mixed gas can be further enhanced.

[0042] The diameter of the tubular reactor 1 is 0.1-0.25m. Compared with the packed reactor of the prior art, the diameter of the tubular reactor 1 is smaller, which is beneficial to improve the uniformity of distribution, the reaction rate of materials, and the conversion rate.

[0043] The length-to-diameter ratio of the tubular reactor 1 is 30:1-50:1, while that of the packed reactor is 20:1-30:1. Compared with the size of the packed reactor in the prior art, the tubular reactor 1 can extend the material residence time, ensure full reaction, and achieve a higher silane conversion rate. The higher the length-to-diameter ratio, the larger the heat transfer area per unit volume, the higher the heat exchange efficiency, and the faster the heating rate.

[0044] To ensure that more than 90% of the reactor space is used for the core reaction, the vertical length of the rotary flow gas distributor 5 is less than 1 / 10 of the reactor length. The gas only stays in the distributor briefly and quickly enters the main reaction zone, reducing side reactions such as premature precipitation of silicon powder.

[0045] Example 2:

[0046] The difference between Example 2 and Example 1 is that the rotary flow gas distributor in Example 2 has a different structure than the rotary flow gas distributor in Example 1. See [link to example]. Figure 6 and Figure 7 As shown, the rotary flow gas distributor 5 in this embodiment is a vortex tube 8 arranged in the radial direction of the cylinder 102. The vortex tube 8 has multiple downward-facing first air holes 801, which facilitates the rotary flow gas distributor 5 to deliver the mixer to multiple positions on the cross section of the tubular reactor 1.

Claims

1. A novel tubular reactor apparatus for producing silane, characterized in that, The tubular reactor (1) is a split structure, including a top cover (101), a cylinder (102) and a bottom cover (103) that are detachably and sealed from top to bottom. The tubular reactor (1) has an inlet (104) and an outlet (105). The inlet (104) is connected in sequence to a material mixer (2) and a material preheater (3) located outside the tubular reactor (1). The lower inner side of the inlet (104) is connected to a rotary flow gas distributor (5) through a connecting pipe (4). The inlet of the rotary flow gas distributor (5) is connected to the outlet of the mixer. The rotary flow gas distributor (5) is detachably connected to the upper part of the cylinder (102) via a support frame (9), with the upper end of the support frame (9) clamped inside the connection between the upper cover (101) and the upper end face of the cylinder (102).

2. The novel tubular reactor apparatus for producing silane according to claim 1, characterized in that, The discharge port (105) is provided with a purge port (11) with a valve on one side, and the purge port (11) is inclined downward.

3. The novel tubular reactor apparatus for producing silane according to claim 1, characterized in that, The rotary flow gas distributor (5) is a spiral tube, which includes a first spiral tube (6) and a second spiral tube (7) connected vertically. The outer diameter of the upper part of the second spiral tube (7) is the same as the outer diameter of the lower part of the first spiral tube (6), and the outer diameter of the second spiral tube (7) decreases from top to bottom.

4. The novel tubular reactor apparatus for producing silane according to claim 3, characterized in that, The pitch of the first spiral tube (6) decreases from top to bottom.

5. A novel tubular reactor apparatus for producing silane according to claim 3, characterized in that, The outlet of the second spiral tube (7) is a gradually expanding outlet (701).

6. The novel tubular reactor apparatus for producing silane according to claim 1, characterized in that, The rotary flow gas distributor (5) is a vortex tube (8) arranged in the radial direction of the cylinder (102), and the vortex tube (8) has a plurality of downward-facing first air holes (801).

7. A novel tubular reactor apparatus for producing silane according to claim 1, characterized in that, The diameter of the tubular reactor (1) is 0.1-0.25m.

8. The novel tubular reactor apparatus for producing silane according to claim 1, characterized in that, The length-to-diameter ratio of the tubular reactor (1) is 30:1-50:

1.

9. A novel tubular reactor apparatus for producing silane according to claim 1, characterized in that, The vertical length of the rotary flow gas distributor (5) in the vertical direction is less than 1 / 10 of the reactor length.

10. A novel tubular reactor apparatus for producing silane according to claim 3, characterized in that, The support frame (9) is a ring frame, and multiple support arms (10) are detachably connected to the ring frame and distributed vertically. The support arms (10) are connected to the tube body of the corresponding spiral tube.

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