High efficiency cold hydrogenation reactor with multiple nozzle distributor

Abstract

A kind of high-efficiency cold hydrogenation reactor with multiple nozzle distributor, including reactor body, gas distributor, nozzle;Its characterized in that, gas distributor is provided with multiple nozzle, installation outer thread is arranged on the upper portion of nozzle shell, center passage is arranged in the middle portion of nozzle shell, center passage extends to the top end of nozzle shell, the radial through-hole connected with center passage is equipped in the top end of nozzle shell, cap is installed in the upper portion of nozzle shell by nut;Nozzle shell lower portion is composed of hollow conical section and cylindrical section, nozzle inlet end plate is provided with installation outer thread;Two-stage flow guide block, primary flow guide block, nozzle inlet end plate are successively installed in the cylindrical section of nozzle, two-stage flow guide block is stacked on primary flow guide block, and primary flow guide block and two-stage flow guide block are fastened in the interior of nozzle shell by the nozzle inlet end plate of lowermost end.The present application solves the problem of nozzle blockage caused by gas phase medium backflow, can extend equipment operation cycle, and can improve reaction efficiency by more than 2%.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polycrystalline silicon production equipment, in particular to a high-efficiency cold hydrogenation reactor with a multi-nozzle gas distributor. BACKGROUND

[0002] In the existing production technology of polycrystalline silicon, the improved Siemens process occupies a dominant position. The main process of the process is to generate raw material gas (trichlorosilane and byproduct silicon chloride) by reacting industrial silicon, hydrogen and hydrogen chloride. The raw material gas is purified by dust removal and rectification process to obtain high-purity trichlorosilane. The high-purity trichlorosilane and hydrogen gas are reacted to generate polycrystalline silicon products.

[0003] In the improved Siemens process, the cold hydrogenation reactor is an important raw material gas generating device. The solid particles of industrial silicon enter the cold hydrogenation reactor from the side inlet of the cold hydrogenation reactor cylinder; the gas phase medium such as hydrogen enters the cold hydrogenation reactor from the bottom head connection pipe of the cold hydrogenation reactor, and then is redistributed by the gas distributor of the reactor. The gas phase medium forms a high-speed fluid into the reactor interior through the nozzle of the gas distributor and blows up the solid particles of industrial silicon to form a fluidized mixed medium. The gas phase medium and the silicon particles are fully contacted to generate raw material gas (silicon chloride and trichlorosilane). In the actual production process, due to uneven flow or flow fluctuation of the gas phase medium, backflow phenomenon is easily formed at the nozzle. Fine solid particles will enter the nozzle interior with the backflow of the gas phase medium and deposit and adhere to the inner wall of the nozzle. Long-term silicon powder deposition will cause silicon caking, thereby causing the nozzle to be blocked and invalid.

[0004] When a large number of nozzles are blocked and invalid, the flow field uniformity in the cold hydrogenation reactor will be broken, causing the flow field in the reactor to be deflected, causing the local gas-solid flow in the reactor to be intensified, and finally causing the reactor cylinder to be eroded and the equipment to be damaged. SUMMARY

[0005] The purpose of the present application is to solve the problem that fine solid particles will enter the nozzle interior with the backflow of the gas phase medium and deposit and adhere to the inner wall of the nozzle, long-term silicon powder deposition will cause silicon caking, thereby causing the nozzle to be blocked and invalid, and the flow field uniformity in the cold hydrogenation reactor is broken, causing the flow field in the reactor to be deflected, causing the local gas-solid flow in the reactor to be intensified, and finally causing the reactor cylinder to be eroded and the equipment to be damaged. A high-efficiency cold hydrogenation reactor with a multi-nozzle distributor is designed to solve the problem of nozzle blockage caused by gas phase medium backflow, prolong the operation cycle of the equipment, and improve the reaction efficiency by more than 2%.

[0006] The technical scheme of the present application is:

[0007] The application discloses a high-efficiency hydrogenation reactor with a multi-nozzle distributor, which comprises a reactor body, a gas distributor, a nozzle, a gas-phase medium inlet, a silicon powder inlet, a raw material gas outlet and a reflux medium inlet; the gas distributor is arranged in the reactor body and is welded to the inner wall of the reactor; the gas-phase medium inlet is arranged at the bottom center of the reactor body; the silicon powder inlet is arranged on the side of the reactor body and is located above the gas distributor; the raw material gas outlet is arranged at the top center of the reactor body; and the reflux medium inlet is arranged on the side of the reactor body, is located above the gas distributor and is opposite to the silicon powder inlet.

[0008] The first-stage flow guide block is composed of a first-stage cylinder section, an annular flow guide piece and a first-stage support, the annular flow guide piece is connected to the middle part of the first-stage cylinder section through the first-stage support, the first-stage cylinder section is a circular ring, the upper end surface of the first-stage cylinder section is provided with a chamfer matched with the second-stage flow guide block, the annular flow guide piece is a metal circular ring with a trumpet-shaped cross section, the inner side of the annular flow guide piece is higher than the outer side, the first-stage supports are uniformly distributed in the circumferential direction, and the number of the first-stage supports is 2-6.

[0009] The second-stage flow guide block is composed of a second-stage cylinder section, an inverted conical flow guide piece and a second-stage support, the inverted conical flow guide piece is connected to the middle part of the second-stage cylinder section through the second-stage support, the inner wall of the second-stage cylinder section is an inclined conical surface, the inclination angle α is 45°-80°, the upper end surface of the second-stage cylinder section is a plane and is provided with a chamfer matched with the hollow conical section in the nozzle shell, the inverted conical flow guide piece is an inverted conical shape, the conical angle β is 90°-120°, the second-stage supports are uniformly distributed in the circumferential direction, and the number of the second-stage supports is 2-6.

[0010] The nozzle shell is provided with a plurality of through holes in the top part of the central through hole, the axis of the through hole and the axis of the nozzle shell form an included angle of 75-90 degrees, the through holes are uniformly distributed in the circumferential direction, and the number of the through holes is 3-8.

[0011] The cap cover is provided with a through hole in the top center thereof for being matched with the nozzle shell.

[0012] All components are manufactured in an integrated form by 3D printing additive processing method.

[0013] The cap cover is connected and fixed with the nozzle shell in a welded form.

[0014] The nozzle inlet end plate is connected and fixed with the nozzle shell in a welded form.

[0015] The annular flow guide piece in the primary flow guide block is in the form of an isosceles trapezoid.

[0016] The beneficial effects of the present application are:

[0017] The high-efficiency cold hydrogenation reactor with a multi-nozzle distributor of the present application is provided with a plurality of nozzles, specific annular flow guide pieces and inverted cone flow guide pieces are arranged in the nozzles, so that under the condition of the same pressure difference, the flow resistance when the gas medium backflows is higher than the flow resistance when the gas medium flows forward, thereby increasing the difficulty of backflow of the gas medium at the nozzle structure, further reducing the solid-phase particles entrained when the gas-phase medium backflows, reducing the deposition and blockage of the solid-phase particles in the nozzle, and finally ensuring the reliability and safety of the cold hydrogenation reactor operation, prolonging the operation period of the equipment, and improving the reaction efficiency by more than 2%. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic view of the high-efficiency cold hydrogenation reactor of the present application;

[0019] Figure 2 is a sectional view of the nozzle of the gas distributor of the reactor of the present application;

[0020] Figure 3 is a structure schematic view of the primary flow guide block of the nozzle of the gas distributor;

[0021] Figure 4 is a structure schematic view of the secondary flow guide block of the nozzle of the gas distributor;

[0022] Figure 5 is a sectional view of the primary flow guide block of the nozzle of the gas distributor;

[0023] Figure 6 is a schematic view of the forward flow path of the gas-phase medium in the nozzle of the gas distributor;

[0024] Figure 7 is a schematic view of the backflow path of the gas-phase medium in the nozzle of the gas distributor;

[0025] Figure 8 is a sectional view of the straight-through nozzle structure;

[0026] In the figure, 1-gas distributor, 2-nozzle, 3-reactor body, 4-gas phase medium inlet, 5-silicon powder inlet, 6-raw material gas outlet, 7-reflux medium inlet, 10-nozzle inlet end plate, 20-first-stage guide block, 21-first-stage cylinder segment, 22-annular guide vane, 23-first-stage support, 30-second-stage guide block, 31-second-stage cylinder segment, 32-inverted conical guide vane, 33-second-stage support, 40-nozzle shell, 41-central passage, 42-through hole, 50-cap, 60-nut. DETAILED DESCRIPTION

[0027] The application will be further described below in conjunction with the accompanying drawings and examples.

[0028] As Figure 1 shown.

[0029] A high-efficiency cold hydrogenation reactor with a multi-nozzle distributor comprises a reactor body 3, a gas distributor 1, a nozzle 2, a gas phase medium inlet 4, a silicon powder inlet 5, a raw material gas outlet 6, and a reflux medium inlet 7. The gas distributor 1 is arranged inside the reactor body 3 and is welded to the inner wall of the reactor. The gas phase medium inlet 4 is arranged at the bottom center of the reactor body. The silicon powder inlet 5 is arranged on the side of the reactor body and is located above the gas distributor 1. The raw material gas outlet 6 is arranged at the top center of the reactor body. The reflux medium inlet 7 is arranged on the side of the reactor body and is located above the gas distributor 1 and opposite to the silicon powder inlet 5.

[0030] As Figure 2 shown, a plurality of nozzles 2 are arranged on the gas distributor 1. The nozzle 2 comprises a nozzle inlet end plate 10, a first-stage guide block 20, a second-stage guide block 30, a nozzle shell 40, a cap 50, and a nut 60. The upper part of the nozzle shell is provided with an external mounting thread. The central passage 41 is arranged in the middle part of the nozzle shell and extends to the top end of the nozzle shell, where a radial gas outlet through hole 42 is arranged. The lower part of the nozzle shell is composed of a hollow conical segment and a cylindrical segment, and the cylindrical segment is provided with an internal mounting thread. The nozzle inlet end plate 10 is provided with an external mounting thread and a central through hole. The cap 50 is installed on the upper part of the nozzle shell 40 and is fastened by the nut 60. The second-stage guide block 30, the first-stage guide block 20, and the nozzle inlet end plate 10 are sequentially installed in the hollow cylindrical segment of the lower part of the nozzle shell, and the second-stage guide block 30 is stacked on the first-stage guide block 20. The first-stage guide block 20 and the second-stage guide block 30 are fastened inside the nozzle shell 40 through the threaded connection between the lowermost nozzle inlet end plate 10 and the nozzle shell 40, and the components are coaxially arranged and installed. The upper part of the central passage 41 in the nozzle shell is provided with radial through holes 42, and the number of radial through holes 42 can be 3-8.

[0031] As Figure 3The first-stage flow guide block 20 is composed of a first-stage cylinder section 21, an annular flow guide piece 22 and a first-stage support 23, the annular flow guide piece 22 is connected to the middle part of the first-stage cylinder section 21 through the first-stage support 23, wherein the first-stage cylinder section is a circular ring, the upper end surface is provided with a chamfer matched with the second-stage flow guide block, the annular flow guide piece 22 is a metal circular ring with a cross section in the shape of a trumpet mouth or an isosceles trapezoid, the inner side is higher than the outer side, the first-stage supports are uniformly distributed in the circumferential direction, and the number of the first-stage supports is 2-6. Figure 5 The annular flow guide piece can also adopt the structure shown in the drawing.

[0032] As shown in the drawing, Figure 4 The second-stage flow guide block 30 is composed of a second-stage cylinder section 31, an inverted conical flow guide piece 32 and a second-stage support 33, the inverted conical flow guide piece is connected to the second-stage cylinder section through the second-stage support; wherein the inner wall of the second-stage cylinder section 31 is a slanting conical surface, the inclination angle a is 45-80°, the upper end surface of the second-stage cylinder section is a plane and is provided with a chamfer matched with the hollow conical section in the nozzle shell body; the inverted conical flow guide piece 32 is in the shape of an inverted circular cone, the cone angle β is 90-120°, the second-stage supports 33 are uniformly distributed in the circumferential direction, and the number of the second-stage supports is 2-6.

[0033] The upper end conical surface of the first-stage cylinder section 21 and the lower end conical surface of the second-stage cylinder section 31 form a matching guarantee for the concentricity, and the upper end conical surface of the second-stage cylinder section 31 and the inner conical surface of the nozzle shell body 40 form a matching guarantee for the concentricity.

[0034] The working principle of the high-efficiency cold hydrogenation reactor with the multi-nozzle distributor is as follows:

[0035] The gas-phase medium enters the cold hydrogenation reactor from the bottom gas-phase medium inlet 4, rises to the gas distributor 1 in the flow direction, the gas-phase medium enters the nozzle 2 from the center opening of the nozzle inlet end plate 10, due to the inertial effect of the medium, the main flow medium forms a jet flow gathered in the center and directly hits the middle conical surface of the second-stage flow guide block 30, the rear conical surface bypasses the inverted conical flow guide piece 32 and enters the central passage 41 of the nozzle shell body 40, then enters the hat cover 50 through the through hole 42 in the upper part of the central passage 41 to form an annular flow channel with the nozzle shell body 40, and finally enters the inside of the cold hydrogenation reactor to mix and react with the silicon particles. Figure 6 The flow path of the gas-phase medium is shown in the drawing.

[0036] In the case of cold hydrogenation reactor shutdown or emergency unloading, the gas phase medium backflows. The gas phase medium forms a ring-shaped flow channel from the cap 50 to the nozzle shell 40 into the nozzle, enters the inside of the nozzle shell 40 through the through hole 42, and under the action of inertia, directly flows to the inverted cone guide vane 32 of the secondary guide block 30, flows along the concave surface of the inverted cone guide vane 32, enters the primary guide block 20 through the ring-shaped flow channel between the cylinder section 31 and the inverted cone guide vane 32. Under the action of inertia, the main flow of the gas phase medium directly flows onto the inner concave surface of the ring-shaped guide vane 22 of the primary guide block 20. At the same time, the internal space of the primary guide block 20 is cut by the ring-shaped guide vane 22 to form two flow channels, i.e. the outer flow channel formed by the ring-shaped guide vane 22 and the primary cylinder section 21, and the inner flow channel formed by the ring-shaped guide vane 22 itself. When the gas phase medium flows to the ring-shaped guide vane 22, the main flow of the medium flows along the inner concave surface of the ring-shaped guide vane 22 to the outer flow channel due to the downward inclination of the ring-shaped guide vane 22 and the difference in area between the inner and outer flow channels of the primary guide block 20, and flows along the inner wall surface of the central through hole of the nozzle inlet end plate 10 to flow out of the nozzle. The backflow path of the gas phase medium is shown in Figure 7 .

[0037] The distributor nozzle of the conventional cold hydrogenation reactor is a straight-through structure, as shown in Figure 8 , and the flow resistance of the gas phase medium is consistent in forward flow and backflow. The nozzle structure of the high-efficiency cold hydrogenation reactor of the present application can ensure high-speed passage of the gas phase medium in forward flow, and when the gas phase medium backflows, the flow distance is longer than that in forward flow, and the flow channel is more complex, so the flow resistance in backflow is greater. Therefore, under the same pressure difference conditions, the cold hydrogenation reactor using the nozzle of the present application has a smaller gas phase backflow than the conventional cold hydrogenation reactor; at the same time, since the gas phase medium flows from the bottom to the top in the ring-shaped flow channel formed by the cap 50 and the nozzle shell 40, when the flow rate of the medium decreases, the silicon particles entrained in the gas phase medium will settle, further preventing the silicon particles from backflowing into the nozzle with the medium, solving the problem of nozzle blockage caused by silicon powder deposition, prolonging the operation cycle of the equipment, and improving the reaction efficiency by more than 2%.

[0038] The part not involved in the present application is the same as the prior art or can be solved by using the prior art.

Claims

1. A high-efficiency cold hydrogenation reactor with a multi-nozzle distributor, comprising a reactor body, a gas distributor, nozzles, a gaseous medium inlet, a silicon powder inlet, a raw material gas outlet, and a reflux medium inlet; the gas distributor is disposed inside the reactor body and welded to the inner wall of the reactor; the gaseous medium inlet is disposed at the bottom center of the reactor body; the silicon powder inlet is disposed on the side of the reactor body and above the gas distributor; the raw material gas outlet is disposed at the top center of the reactor body; the reflux medium inlet is disposed on the side of the reactor body and above the gas distributor, opposite to the silicon powder inlet, characterized in that, The gas distributor is equipped with multiple nozzles, each nozzle including a nozzle inlet end plate, a primary guide block, a secondary guide block, a nozzle housing, a cap, and a nut. The upper part of the nozzle housing has an external mounting thread, and a central channel is located in the middle of the nozzle housing, extending to the top of the nozzle housing. The top of the nozzle housing has a radial through hole connected to the central channel. The cap is installed on the upper part of the nozzle housing by a nut and covers the radial through hole. The lower part of the nozzle housing consists of a hollow conical section and a cylindrical section, with an internal mounting thread on the cylindrical section. The nozzle inlet end plate has an external mounting thread and a central through hole. The secondary guide block, the primary guide block, and the nozzle inlet end plate are sequentially installed in the hollow cylindrical section of the lower part of the nozzle housing, with the secondary guide block stacked on top of the primary guide block. The primary and secondary guide blocks are secured inside the nozzle housing by the lowermost nozzle inlet end plate. All components are coaxially arranged and installed. The primary guide block includes an annular guide vane, which is a metal ring with a flared cross-section, the inner edge of which is higher than the outer edge. The secondary guide block includes a secondary cylindrical section and an inverted conical guide vane. The inner wall of the secondary cylindrical section is an oblique conical surface, and the inverted conical guide vane is an inverted conical shape. The primary guide block also includes a primary cylindrical section and a primary support. The annular guide vane is connected to the middle of the primary cylindrical section through the primary support. The primary cylindrical section is circular, and its upper end face is provided with a chamfer that matches that of the secondary guide block. The primary supports are evenly distributed circumferentially. The secondary guide block also includes a secondary cylindrical section and a secondary support. The inverted conical guide vane is connected to the middle of the secondary cylindrical section through the secondary support. The inclination angle α of the inclined conical surface of the inner wall of the secondary cylindrical section is 45°~80°. The upper end face of the secondary cylindrical section is a plane and is provided with a chamfer that matches the hollow conical section inside the nozzle housing. The cone angle β of the inverted conical guide vane is 90°~120°. The secondary support is circumferentially distributed.

2. The high-efficiency cold hydrogenation reactor according to claim 1, characterized in that, The number of primary supports is 2 to 6.

3. The high-efficiency cold hydrogenation reactor according to claim 1, characterized in that, The number of secondary supports is 2 to 6.

4. The high-efficiency cold hydrogenation reactor according to claim 1, characterized in that, The nozzle housing has several through holes at the top of its central through hole. The axis of the through holes forms an angle of 75 to 90 degrees with the axis of the nozzle housing. The through holes are evenly distributed around the circumference, and the number of through holes is 3 to 8.

5. The high-efficiency cold hydrogenation reactor according to claim 1, characterized in that, The cap has a U-shaped cross-section along its axial direction, and a through hole is opened at the center of its top for installation with the nozzle housing.

6. The high-efficiency cold hydrogenation reactor according to any one of claims 1-5, characterized in that, All components are manufactured in a single piece using 3D printing additive manufacturing.

7. The high-efficiency cold hydrogenation reactor according to claim 1, characterized in that, The cap and nozzle housing are connected and fixed by welding.

8. The high-efficiency cold hydrogenation reactor according to claim 1, characterized in that, The nozzle inlet end plate is connected and fixed to the nozzle housing by welding.

9. The high-efficiency cold hydrogenation reactor according to claim 1, characterized in that, The cross-section of the annular guide vane in the primary guide block is an isosceles trapezoid.

Images