Flow guide assembly for tail gas pipe of reduction furnace

Abstract

The utility model relates to the technical field of polycrystalline silicon production, in particular to a reduction furnace tail gas pipe flow guide assembly which comprises a flow guide cylinder. The guide cylinder comprises a feeding part, a discharging part and a supporting structure; the feeding part is of a conical barrel-shaped structure; the discharging part is in a straight cylinder shape; the feeding end of the discharging part is fixedly arranged at the discharging end of the feeding part; the discharging part is communicated with the feeding part; the inner side end of the supporting structure is fixedly arranged on the outer wall of the discharging part; the supporting structure is provided with a channel communicating with the feeding end of the feeding part and the discharging end of the discharging part. A preset distance is formed between the inner side end of the supporting structure and the outer side end of the supporting structure. By adopting the device, the tail gas pipeline is prevented from forming silicon, and good liquidity of gas in the reduction furnace is guaranteed; the workload caused by unblocking is reduced, and the leakage risk of the unblocking flange is reduced; the generation of abnormal silicon materials is reduced, the utilization rate of trichlorosilane is improved, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon production, in particular to a reduction furnace tail gas pipe guide component. Background Art

[0002] The Siemens improved process is currently mainly used to produce polysilicon. During the production process, the heated vaporized trichlorosilane needs to be mixed with hydrogen in a certain molar ratio, and the mixed gas enters the reduction furnace for reduction reaction. The reduction reaction will produce by-products such as hydrogen chloride, silicon tetrachloride and dichlorodihydrogen silicon; the by-products and unreacted trichlorosilane and hydrogen are collectively referred to as reaction tail gas; the reaction tail gas is discharged through the tail gas pipeline on the chassis of the reduction furnace. The reaction tail gas will undergo a high-temperature deposition reaction on the metal inner wall of the tail gas pipeline, and polysilicon will be generated on the inner wall of the tail gas pipeline. After silicon is deposited on the inner wall of the pipeline, the inner diameter of the tail gas pipeline will be reduced, affecting the circulation of gas in the reduction furnace and affecting the normal operation of the reduction furnace; moreover, the silicon deposited in the tail gas pipeline is an unqualified silicon product, which consumes trichlorosilane and wastes part of the circulating raw materials; moreover, regular cleaning of the silicon deposited on the inner wall of the tail gas pipeline increases the workload, wastes consumables, and frequent disassembly of the flange increases the risk of leakage. Utility Model Content

[0003] In view of this, the utility model provides a reduction furnace tail gas pipe guide component, the main purpose of which is to prevent silicon from forming in the tail gas pipeline and ensure good gas flow in the reduction furnace; reduce the workload caused by clearing blockage, save clearing consumables, and reduce the leakage risk of the clearing flange; reduce the generation of abnormal silicon material, improve the utilization rate of trichlorosilane, and reduce costs.

[0004] In order to achieve the above purpose, the utility model mainly provides the following technical solutions:

[0005] The embodiment of the utility model provides a reduction furnace tail gas pipe guide assembly, comprising: a guide tube;

[0006] The guide tube comprises: a feeding part, a discharging part and a supporting structure;

[0007] The feeding part is a conical cylindrical structure;

[0008] The discharge part is a straight-cylindrical type; the feed end of the discharge part is fixedly arranged at the discharge end of the feed part; the discharge part is connected to the feed part;

[0009] The inner end of the support structure is fixedly arranged on the outer wall of the discharge portion;

[0010] The support structure is provided with a channel connecting a feeding end of the feeding part and a discharging end of the discharging part;

[0011] The inner side end of the supporting structure has a predetermined distance from the outer side end of the supporting structure.

[0012] Furthermore, there are at least two flow guide tubes; and at least two flow guide tubes are arranged in sequence and at intervals.

[0013] Furthermore, a connecting member is provided between two adjacent guide tubes;

[0014] The two ends of the connecting member are respectively mounted on the two adjacent flow guide cylinders.

[0015] Furthermore, at least two of the guide tubes are arranged in sequence from top to bottom;

[0016] A bottom support is arranged on the top of the lower end of the guide cylinder at the lowest end.

[0017] Furthermore, the connecting member is a frame structure composed of a plurality of connecting rods.

[0018] Furthermore, the feeding part and the discharging part are integrated.

[0019] Furthermore, the guide tube is made of silicon nitride, ceramic or stainless steel profile.

[0020] Furthermore, the predetermined distance is 1 / 5 to 1 / 2 of the outer diameter of the discharge portion.

[0021] Furthermore, the feeding part is conical.

[0022] Further, the discharging portion is cylindrical;

[0023] The bottom support is a circular frame structure; the outer diameter of the bottom support does not exceed the outer diameter of the discharge portion.

[0024] By means of the above technical solution, the reduction furnace tail gas pipe guide assembly of the utility model has at least the following advantages:

[0025] It can prevent silicon from forming in the tail gas pipeline and ensure good gas flow in the reduction furnace; reduce the workload caused by clearing blockage, save clearing consumables, and reduce the leakage risk of clearing flanges; reduce the generation of abnormal silicon materials, improve the utilization rate of trichlorosilane, and reduce costs.

[0026] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the utility model in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a front view of a reduction furnace tail gas pipe guide assembly provided by an embodiment of the utility model;

[0028] Figure 2 A schematic top view of a reduction furnace tail gas pipe guide assembly provided in an embodiment of the utility model;

[0029] Figure 3 A schematic diagram of a reduction furnace tail gas pipe guide assembly provided by an embodiment of the utility model;

[0030] Figure 4 A schematic diagram of a reduction furnace tail gas pipe guide assembly provided in an embodiment of the utility model being installed in a tail gas pipeline.

[0031] As shown in the figure:

[0032] 1 is the feed part, 2 is the discharge part, 3 is the support structure, 4 is the connecting member, 5 is the bottom support, and 6 is the exhaust gas pipeline. DETAILED DESCRIPTION

[0033] In order to further explain the technical means and effects adopted by the utility model to achieve the predetermined utility model purpose, the specific implementation methods, structures, features and effects of the utility model application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0034] like Figures 1 to 4 As shown, an embodiment of the utility model proposes a reduction furnace tail gas pipe guide assembly, including: a guide tube; the guide tube includes: a feed part 1, a discharge part 2 and a support structure 3; the feed part 1 is a conical cylindrical structure; preferably, the feed part 1 is conical, which is convenient for processing and has good gas fluidity. Of course, it is not ruled out that the feed part 1 is a polygonal pyramid structure. The discharge part 2 is a straight cylinder; preferably, the discharge part 2 is a cylindrical type; the bottom support 5 is a circular frame structure; the outer diameter of the bottom support 5 does not exceed the outer diameter of the discharge part 2, so as to ensure stable support for the guide tube while avoiding affecting the airflow outside the guide tube. The bottom support 5 is in contact with the bottom of the vertical tail gas pipeline 6. The feed end of the discharge part 2 is fixedly arranged at the discharge end of the feed part 1; the discharge part 2 is connected to the feed part 1; the inner end of the support structure 3 is fixedly arranged on the outer wall of the discharge part 2; the support structure 3 has a channel connecting the feed end of the feed part 1 and the discharge end of the discharge part 2; the inner end of the support structure 3 and the outer end of the support structure 3 have a predetermined distance. The support structure 3 is arranged along the periphery of the discharge part 2 to prevent the guide tube from shaking at will. Preferably, the predetermined distance is 1 / 5 to 1 / 2 of the outer diameter of the discharge part 2 to ensure the fluidity of the gas in the gap between the guide tube and the exhaust pipeline 6.

[0035] An embodiment of the utility model provides a reduction furnace tail gas pipe guide component, which can prevent silicon from forming in the tail gas pipeline 6, ensure good gas flowability in the reduction furnace, and make the silicon rods dense and smooth in appearance; reduce the workload caused by clearing blockages, save clearing consumables, and reduce the leakage risk of clearing flanges; reduce the generation of abnormal silicon materials, improve the utilization rate of trichlorosilane, and reduce costs.

[0036] In this embodiment, preferably, there are at least two guide tubes; at least two guide tubes are arranged in sequence at intervals to accommodate exhaust gas lines 6 of different lengths, and different numbers of guide tubes can be arranged as needed. Further preferably, a connecting member 4 is arranged between two adjacent guide tubes; the two ends of the connecting member 4 are respectively placed on the top of the two adjacent guide tubes to maintain the spacing between the two guide tubes and to support the guide tubes. Preferably, the connecting member 4 is a frame structure composed of multiple connecting rods, so as to provide support for the guide tube while reducing the impact on the circulation of the exhaust gas.

[0037] It is further preferred that at least two guide tubes are arranged in sequence from top to bottom; a bottom support 5 is provided on the top of the lower end of the guide tube at the lowest end; the commonly used exhaust gas pipeline 6 extends in the up and down directions, and at least two guide tubes are arranged in the up and down directions to adapt to the current exhaust gas pipeline 6; a bottom support 5 is provided on the top of the lower end of the guide tube at the lowest end to form support for at least two guide tubes.

[0038] In this embodiment, the feed part 1 and the discharge part 2 are preferably integrated, and the structure is reliable. Of course, it is not excluded that the feed part 1 and the discharge part 2 are fixed by welding.

[0039] In this embodiment, the guide tube is preferably made of silicon nitride, ceramic or stainless steel profile, which is resistant to high temperature and corrosion.

[0040] In the implementation of a reduction furnace tail gas pipe guide assembly proposed in an embodiment of the utility model, the guide tube is installed in the vertical tail gas hole on the reduction furnace chassis, and two or more guide tubes can be connected in series in each tail gas hole. The reaction tail gas enters the guide tube and the gap between the guide tube and the tail gas pipeline 6 at the same time. The tail gas outside the guide tube passes through the conical guide and enters the area between the discharge part 2 of the guide tube and the inside of the tail gas pipeline 6. Due to the reduction of the cross-sectional area, the reduction furnace tail gas quickly passes through the inner wall of the tail gas pipeline 6, and the material molecules in the tail gas have a short residence time and are not easy to deposit. At the same time, the guide tube blocks the reaction tail gas from diffusing to the inner wall of the tail gas pipeline 6, so that part of the high-temperature gas flows away inside the guide tube. Since the guide tube divides the tail gas in the tail gas pipeline 6, the amount of tail gas cooled by the jacket cooling water on the tail gas pipeline 6 is relatively small, and the tail gas temperature in the gap area between the guide tube and the tail gas pipeline 6 is relatively low. The reduction in the temperature of the inner wall of the tail gas pipeline 6 further reduces the silicon deposition on the metal inner wall. After long-term operation, the outer wall surface of the guide tube is slightly scaled. The guide tube can be lifted out from above the exhaust hole of the chassis, simply cleaned, and then placed in the vertical exhaust pipeline 6. There is no need to disassemble the flange of the exhaust pipeline 6 to avoid the risk of leakage.

[0041] An embodiment of the utility model provides a reduction furnace tail gas pipe guide assembly. After testing, it is found that the structure of the original equipment is not changed and it is very convenient to install on the existing equipment. According to the operation, the inner wall of the tail gas pipeline 6 is not siliconized, which reduces the deviation of the airflow in the reduction furnace, the appearance consistency of the silicon rods in each tail gas hole area is good, and the stability of the reduction furnace operation is improved.

[0042] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] The standard parts used in the utility model can all be purchased from the market, and special-shaped parts can be customized according to the instructions and the drawings. The specific connection methods of each part adopt the conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt the conventional models in the existing technology, and the circuit connection adopts the conventional connection method in the existing technology, which will not be described in detail here.

[0044] The above is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A reduction furnace tail gas pipe guide assembly, characterized in that: Including: guide tube; The guide tube comprises: a feeding part, a discharging part and a supporting structure; The feeding part is a conical cylindrical structure; The discharge part is a straight-cylindrical type; the feed end of the discharge part is fixedly arranged at the discharge end of the feed part; the discharge part is connected to the feed part; The inner end of the support structure is fixedly arranged on the outer wall of the discharge portion; The support structure is provided with a channel connecting a feeding end of the feeding part and a discharging end of the discharging part; The inner side end of the supporting structure has a predetermined distance from the outer side end of the supporting structure.

2. The reduction furnace tail gas pipe guide assembly according to claim 1, characterized in that: There are at least two flow guide tubes; and at least two flow guide tubes are arranged in sequence and at intervals.

3. The reduction furnace tail gas pipe guide assembly according to claim 2, characterized in that: A connecting member is provided between two adjacent guide tubes; The two ends of the connecting member are respectively mounted on the two adjacent flow guide cylinders.

4. The reduction furnace tail gas pipe guide assembly according to claim 3, characterized in that: At least two of the guide tubes are arranged in sequence from top to bottom; A bottom support is arranged on the top of the lower end of the guide cylinder at the lowest end.

5. The reduction furnace tail gas pipe guide assembly according to claim 4, characterized in that: The connecting member is a frame structure composed of a plurality of connecting rods.

6. The reduction furnace tail gas pipe guide assembly according to claim 1, characterized in that: The feeding part and the discharging part are integrated.

7. The reduction furnace tail gas pipe guide assembly according to claim 6, characterized in that: The guide tube is made of silicon nitride, ceramic or stainless steel profile.

8. The reduction furnace tail gas pipe guide assembly according to claim 1, characterized in that: The predetermined distance is 1 / 5 to 1 / 2 of the outer diameter of the discharge portion.

9. The reduction furnace tail gas pipe guide assembly according to claim 1, characterized in that: The feeding part is conical.

10. The reduction furnace tail gas pipe guide assembly according to claim 4, characterized in that: The discharging portion is cylindrical; The bottom support is a circular frame structure; the outer diameter of the bottom support does not exceed the outer diameter of the discharge portion.

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