Anti-disproportionation system for polycrystalline silicon production

Abstract

The utility model provides an anti-disproportionation system for polycrystalline silicon production, which relates to the technical field of polycrystalline silicon production, and comprises a first reaction column with a first opening and a first outlet, a first communicating pipe for communicating is arranged between the first opening and the first outlet, a first valve group is arranged on the first communicating pipe, and the first communicating pipe is communicated with a feeding pipe; the second reaction column is provided with a second opening and a second outlet, a second communicating pipe for communicating is arranged between the second opening and the second outlet, a second valve group is arranged on the second communicating pipe, and the second communicating pipe is communicated with a discharging pipe; a first connecting pipe and a second connecting pipe are respectively arranged between the first communicating pipe and the second communicating pipe, the first connecting pipe is close to the feeding pipe, and the second connecting pipe is close to the discharging pipe; and a communicating valve is arranged on the first connecting pipe. According to the utility model, the sufficient reaction of dichlorosilane can be realized, and the content of impurities such as boron and phosphorus in the system is effectively reduced, so that the quality of a polycrystalline silicon product is improved, and the service life of a resin catalyst is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon production, in particular to a deproportionation system for polysilicon production. Background Art

[0002] At present, in the process of producing trichlorosilane as the raw material by the anti-disproportionation reaction in the resin reaction column, the following problems often occur: 1. Resin deactivation and low conversion rate caused by differences in the reaction column feeding process: If the material enters and exits from the bottom of the reaction column, the contact time between the resin and the material can be increased, and the disilicon conversion rate and impurity adsorption rate can be improved. However, as the filtration effect of the liquid phase filter in the later tail gas recovery section decreases, the tetrasilicon entering the anti-disproportionation reaction will carry silicon powder. When the tetrasilicon with silicon powder enters the anti-disproportionation column, it will not only block the water cap and increase the column pressure difference, but also cause the resin to be entrained with silicon powder, which will lead to resin deactivation in severe cases. If the material enters and exits from the top of the reaction column and exits from the bottom, the contact time between the resin and the material will be shortened. However, even if there is silicon powder in the resin column in the later stage, the top-in and bottom-out can bring out the silicon powder as much as possible, reduce the pressure difference of the column, and prevent the resin from being entrained by the silicon powder, but the conversion rate is lower than the former and the adsorption effect is poor; 2. The difference between series and parallel reaction columns: If the material enters each reaction column at the same time, at this time, the reaction columns are in a parallel state. Although this state can meet the larger dichlorosilane treatment requirements, the conversion rate and adsorption rate are lower than the step-by-step reaction column feeding mode, that is, when each reaction is in a series state; 3. The difference between the initial and final stages of operation: In the initial stage, the resin activity of the reaction column is better and can accept high-load operation. In the later stage of operation, the resin activity decreases. If the reaction columns are still used in parallel to achieve the effect of simultaneous feeding, the conversion rate will be low, causing dichlorosilane to accumulate continuously in the system, and also causing impurities such as boron and phosphorus to increase and enrich. Utility Model Content

[0003] In order to solve the problems of insufficient reaction of dichlorodihydrogen silicon in each reaction column, which leads to an increase in impurities such as boron and phosphorus, and a shortened service life of the resin catalyst, the utility model provides a deproportionation system for polysilicon production, which can achieve sufficient reaction of dichlorodihydrogen silicon, effectively reduce the content of impurities such as boron and phosphorus in the system, thereby improving the quality of polysilicon products and extending the service life of the resin catalyst.

[0004] The technical solution adopted in this utility model is:

[0005] Provided is a deproportionation system for polysilicon production, comprising:

[0006] A first reaction column, the first reaction column has a first opening and a first outlet, a first connecting pipe is provided between the first opening and the first outlet, a first valve group is provided on the first connecting pipe, and a feed pipe is connected to the first connecting pipe; a second reaction column, the second reaction column has a second opening and a second outlet, a second connecting pipe is provided between the second opening and the second outlet, a second valve group is provided on the second connecting pipe, and a discharge pipe is connected to the second connecting pipe; a first connecting pipe and a second connecting pipe are respectively provided between the first connecting pipe and the second connecting pipe, the first connecting pipe is close to the feed pipe, and the second connecting pipe is close to the discharge pipe; a connecting valve is provided on the first connecting pipe.

[0007] In some embodiments of the present invention, the first valve group includes a first valve, a second valve, a third valve, a fourth valve and a fifth valve distributed in sequence on the first connecting pipe, the first valve is located at the first opening, and the fifth valve is located at the first outlet; the connection between the feed pipe and the first connecting pipe is located between the second valve and the third valve; the connection between the first connecting pipe and the first connecting pipe is located between the first valve and the second valve, and the connection between the second connecting pipe and the first connecting pipe is located between the fourth valve and the fifth valve.

[0008] In some embodiments of the present invention, the second valve group includes a sixth valve, a seventh valve, an eighth valve, a ninth valve and a tenth valve distributed in sequence on the second connecting pipe, the sixth valve is located at the second opening, and the seventh valve is located at the second outlet; the connection between the discharge pipe and the second connecting pipe is located between the eighth valve and the ninth valve; the connection between the second connecting pipe and the first connecting pipe is located between the sixth valve and the seventh valve, and the connection between the second connecting pipe and the second connecting pipe is located between the ninth valve and the tenth valve.

[0009] In some embodiments of the present invention, the first valve, the fifth valve, the sixth valve, the tenth valve and the connecting valve are all cut-off valves, and the second valve, the third valve, the fourth valve, the seventh valve, the eighth valve, the ninth valve and the tenth valve are all manual valves.

[0010] In some embodiments of the present invention, the first reaction column further includes a first adsorption column, and the second reaction column further includes a second adsorption column.

[0011] The beneficial effects of the utility model are:

[0012] 1. The material is transported to the first connecting pipe through the feed pipe. Since the first connecting pipe is located between the first opening and the first outlet of the first reaction column, the material can enter the first opening of the first reaction column and then be discharged from the first outlet, or it can enter the first outlet of the first reaction column and then be discharged from the first opening. The flow direction of the material can be adjusted by the first valve group set on the first connecting pipe. Similarly, since the second connecting pipe is connected to the first connecting pipe through the first connecting pipe and the second connecting pipe respectively, the material entering the second connecting pipe can achieve different inflow and outflow directions of the material in the second reaction column under the adjustment of the second valve group, thereby enabling the materials in the first and second reaction columns to switch from low inflow and high outflow to high inflow and low outflow;

[0013] 2. By providing a connecting valve on the first connecting pipe, and using the connecting valve in conjunction with the first valve group on the first connecting pipe and the second valve group on the second connecting pipe, the material conveying relationship between the first reaction column and the second reaction column can be adjusted, that is, the first reaction column and the second reaction column can be used in series or parallel for material conveying. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 The figure is a schematic flow diagram of a deproportionation system for polysilicon production;

[0016] Figure 2 Schematic diagram of the process when the first reaction column and the second reaction column are connected in parallel Figure 1 ;

[0017] Figure 3 Schematic diagram of the process when the first reaction column and the second reaction column are connected in parallel Figure 2 ;

[0018] Figure 4 Schematic diagram of the process when the first reaction column and the second reaction column are connected in series Figure 1 ;

[0019] Figure 5 Schematic diagram of the process when the first reaction column and the second reaction column are connected in series Figure 2 .

[0020] Reference numerals:

[0021] 1-first reaction column, 10-first connecting pipe, 11-first valve, 12-second valve, 13-third valve, 14-fourth valve, 15-fifth valve, 2-second reaction column, 20-second connecting pipe, 21-sixth valve, 22-seventh valve, 23-eighth valve, 24-ninth valve, 25-tenth valve, 3-first connecting pipe, 30-connecting valve, 4-second connecting pipe, 5-feed pipe, 6-discharge pipe. DETAILED DESCRIPTION

[0022] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0023] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention.

[0024] The embodiments of the utility model are described in detail below with reference to the accompanying drawings.

[0025] Example

[0026] like Figure 1 As shown, this embodiment provides a deproportionation system for polysilicon production, comprising:

[0027] A first reaction column 1 having a first opening and a first outlet, a first connecting pipe 10 is provided between the first opening and the first outlet, a first valve 11 is provided on the first connecting pipe 10, and a feed pipe 5 is connected to the first connecting pipe 10;

[0028] The second reaction column 2 has a second opening and a second outlet, a second connecting pipe 20 is provided between the second opening and the second outlet, a second valve 12 group is provided on the second connecting pipe 20, and a discharge pipe 6 is connected to the second connecting pipe 20; a first connecting pipe 3 and a second connecting pipe 4 are respectively provided between the first connecting pipe 10 and the second connecting pipe 20, the first connecting pipe 3 is close to the feed pipe 5, and the second connecting pipe 4 is close to the discharge pipe 6; a connecting valve 30 is provided on the first connecting pipe 3.

[0029] Both the first reaction column 1 and the second reaction column 2 are resin reaction columns used to process dichlorosilane, with excess silicon tetrachloride to complete the anti-disproportionation reaction. The first opening and first outlet of the first reaction column 1 are used for material transportation, while the second opening and second outlet of the second reaction column 2 are also used for material transportation. The first opening is located above the first reaction column 1, and the first outlet is located below the first reaction column 1; the second opening is located above the second reaction column 2, and the second outlet is located below the second reaction column 2. After the feed pipe 5 enters the first connecting pipe 10, the material on the first reaction column 1 can be adjusted to be input from the first opening and output from the first outlet, or to be input from the first outlet on the first reaction column 1 and output from the first opening, according to the usage mode of the first valve 11 group installed on the first connecting pipe 10. Similarly, the second valve 12 group on the second connecting pipe 20 can also adjust the material on the second reaction column 2 to be input from the second opening and output from the second outlet, or to be input from the second outlet and output from the second opening. In addition, a connecting valve 30 is provided on the first connecting pipe 3 connected between the first connecting pipe 10 and the second connecting pipe 20 to cooperate with the material input and output mode between the first reaction column 1 and the second reaction column 2, so as to achieve the material input and output mode between the first reaction column 1 and the second reaction column 2. The following four situations can be achieved: 1. The two are connected in parallel, which can achieve the effect of high input and low output on the first reaction column 1 and the second reaction column 2 at the same time; 2. The two are connected in parallel, which can achieve the effect of low input and high output on the first reaction column 1 and the second reaction column 2 at the same time; 3. The two are connected in series, which can first achieve the effect of high input and low output on the first reaction column 1, and then achieve the effect of low input and high output on the second reaction column 2; 4. The two are connected in series, which can first achieve the effect of low input and high output on the first reaction column 1, and then achieve the effect of high input and low output on the second reaction column 2, thereby achieving the full reaction of dichlorodihydrosilane, extending the service life of the resin catalyst, and effectively reducing the content of impurities such as boron and phosphorus in the system, thereby improving the quality of polysilicon products.

[0030] Further, such as Figure 1 As shown, the first valve 11 group includes a first valve 11, a second valve 12, a third valve 13, a fourth valve 14 and a fifth valve 15, which are sequentially distributed on the first connecting pipe 10. The first valve 11 is located at the first opening and the fifth valve 15 is located at the first outlet; the connection between the feed pipe 5 and the first connecting pipe 10 is located between the second valve 12 and the third valve 13; the connection between the first connecting pipe 3 and the first connecting pipe 10 is located between the first valve 11 and the second valve 12, and the connection between the second connecting pipe 4 and the first connecting pipe 10 is located between the fourth valve 14 and the fifth valve 15.

[0031] The distribution direction of each valve in the first valve 11 group is along the direction from the first opening to the first outlet of the first reaction column 1. There is no requirement for the spacing between the valves. It is only necessary that the first valve 11 is located on the first opening of the first reaction column 1, the fifth valve 15 is located on the first outlet of the first reaction column 1, and the connection between the feed pipe 5 and the first connecting pipe 10 is located between the second valve 12 and the third valve 13. The connection between the connecting valve 30 and the first connecting pipe 10 is located between the first valve 11 and the second valve 12. The connection between the first connecting pipe 10 and the second connecting pipe 4 is located between the fourth valve 14 and the fifth valve 15.

[0032] During use, the material input from the feed pipe 5 can be transported in two directions. One is toward the second valve 12. After passing through the second valve 12, the material can be transported in two ways: one is to pass through both the first valve 11 and the connecting valve 30 simultaneously, and the other is to close the connecting valve 30 and allow the material to pass only through the first valve 11. The other is to be transported toward the third valve 13. After passing through the third valve 13, the material can be transported in two ways at the outlet of the fourth valve 14: one is to enter the fifth valve 15 and the second connecting pipe 20 simultaneously, and the other is to enter the fifth valve 15 and the second connecting pipe 20 simultaneously, but compared with the former, it will pass through the ninth valve 24 and will not enter the ninth valve 24 in the second connecting pipe 20. The various methods of material transportation mentioned above differ only in whether the material is transported in the first reaction column 1 and the second reaction column 2 in a high-input and low-output or low-input and high-output manner.

[0033] Further, such as Figure 1-5 As shown, the second valve group 12 includes a sixth valve 21, a seventh valve 22, an eighth valve 23, a ninth valve 24 and a tenth valve 25, which are sequentially distributed on the second connecting pipe 20. The sixth valve 21 is located at the second opening, and the seventh valve 22 is located at the second outlet; the connection between the discharge pipe 6 and the second connecting pipe 20 is located between the eighth valve 23 and the ninth valve 24; the connection between the second connecting pipe 20 and the first connecting pipe 3 is located between the sixth valve 21 and the seventh valve 22, and the connection between the second connecting pipe 20 and the second connecting pipe 4 is located between the ninth valve 24 and the tenth valve 25.

[0034] The valves included in the second valve group 12 are sequentially distributed in the direction from the second opening to the second outlet of the second connecting pipe 20. There is no requirement for the spacing between the valves. It is only necessary that the sixth valve 21 is located at the second opening of the second reaction column 2, and the tenth valve 25 is located at the second outlet of the second reaction column 2. The sixth valve 21 and the seventh valve 22 located on both sides of the connecting valve 30 can control the direction of the material transported from the connecting valve 30. The material transported through the connecting valve 30 has the following four situations: 1. If Figure 2As shown, when the third valve 13 and the fourth valve 14 on the first connecting pipe 10 are closed, the first valve 11, the second valve 12 and the fifth valve 15 are opened, and the connecting valve 30 is also opened, the material will enter from the feed pipe 5 and enter the first reaction column 1 and the second reaction column 2 through the first connecting pipe 10 and the second connecting pipe 20 respectively. At this time, the material enters each reaction column in a high-input and low-output manner, and the first reaction column 1 and the second reaction column 2 are in a parallel state, that is, the material enters each reaction column at the same time. This situation is suitable for working conditions with a large load in the later stage of operation; 2. Figure 3 As shown, when the third valve 13 and the fourth valve 14 on the first connecting pipe 10 are opened, the first valve 11, the second valve 12 and the fifth valve 15 are closed, and the connecting valve 30 is still open, the material will enter from the feed pipe 5 and enter the first reaction column 1 and the second reaction column 2 through the first connecting pipe 10 and the second connecting pipe 20 respectively. At this time, the material enters each reaction column in a low-in and high-out situation, and the first reaction column 1 and the second reaction column 2 are still in a parallel state, that is, the material enters each reaction column at the same time. This situation is suitable for working conditions with a large initial load; 3. Figure 4 As shown, when the first valve 11, the second valve 12 and the fifth valve 15 on the first connecting pipe 10 are opened, the third valve 13 and the fourth valve 14 are closed, and the connecting valve 30 is also closed, the material input by the feeding pipe can only enter from the first opening of the first reaction column 1 and then be discharged from the first outlet. At this time, the first reaction column 1 and the second reaction column 2 are in a series state, that is, the material first enters the first reaction column 1 for reaction and then enters the second reaction column 2 for reaction. This situation is applicable to the working condition where the conversion rate in the anti-disproportionation system decreases or the adsorption column effect decreases; 4. Figure 5 As shown, when the first valve 11, the third valve 13, the fourth valve 14 and the fifth valve 15 are opened, the second valve 12 is closed, and the connecting valve 30 is opened, the material input by the feed pipe can only enter from the first outlet of the first reaction column 1, and then be discharged from the first opening, and then pass through the first connecting pipe 3 and enter the second connecting pipe 20 through the connecting valve 30. At this time, the first reaction column 1 and the second reaction column are in a series state, which is also applicable to the working conditions where the conversion rate of the anti-disproportionation system decreases and the adsorption effect of the adsorption column decreases.

[0035] During use, as in the four situations described above, for the first situation, after the first valve 11 group on the first connecting pipe 10 is operated accordingly, the seventh valve 22 and the eighth valve 23 on the second connecting pipe 20 should be closed, and the sixth valve 21, the ninth valve 24, and the tenth valve 25 should be opened. At this time, the material inputted by the feed pipe will enter the first reaction column 1 and the second reaction column 2 simultaneously, respectively, to achieve a parallel state, and both are high-input and low-output from the reaction columns. For the second situation, after the first valve 11 group on the first connecting pipe 10 is operated accordingly, the sixth valve 21, the seventh valve 22, the eighth valve 23, and the tenth valve 25 on the second connecting pipe 20 are opened, and the ninth valve 24 is closed. At this time, the material inputted by the feed pipe will also enter the first reaction column 1 and the second reaction column 2 simultaneously, respectively, to achieve a parallel state, and both are low-input and high-output from the reaction columns. For the third case, after the first valve 11 group on the first connecting pipe 10 performs the corresponding operation, the sixth valve 21, the seventh valve 22, the eighth valve 23 and the tenth valve 25 on the second connecting pipe 20 are opened, and the ninth valve 24 is closed. The material input by the feed pipe will first enter high and exit low on the first reaction column 1, then enter the second connecting pipe 20 through the second connecting pipe 4, then enter low and exit high on the second reaction column 2, and finally be discharged from the discharge pipe 6, realizing the series connection between the first reaction column 1 and the second reaction column 2. For the fourth case, after the first valve 11 group on the first connecting pipe 10 is operated accordingly, the sixth valve 21, the ninth valve 24 and the tenth valve 25 on the second connecting pipe 20 are opened, and the seventh valve 22 and the eighth valve 23 are closed. At this time, the material input by the feed pipe will first enter low and exit high on the first reaction column 1, and then enter the second connecting pipe 20 through the first connecting pipe 3 provided with the connecting valve 30. After entering high and exiting low from the second reaction column 2, it is discharged from the discharge pipe 6, realizing the series connection of the first reaction column 1 and the second reaction column 2. That is, by adjusting the opening and closing states of the first valve 11 group, the second valve 12 group and the connecting valve 30, the material in each reaction column can be arbitrarily converted from low entry and high exit to high entry and low exit, thereby achieving full reaction of dichlorodihydrosilane, extending the service life of the resin catalyst, and effectively reducing the content of impurities such as boron and phosphorus in the system, thereby improving the quality of polysilicon products.

[0036] Furthermore, the first valve 11, the fifth valve 15, the sixth valve 21, the tenth valve 25 and the connecting valve 30 are all cut-off valves, and the second valve 12, the third valve 13, the fourth valve 14, the seventh valve 22, the eighth valve 23, the ninth valve 24 and the tenth valve 25 are all manual valves.

[0037] A shut-off valve is a type of actuator in an automation system. It consists of a multi-spring pneumatic diaphragm actuator or a floating piston actuator and a regulating valve. It receives signals from a regulating instrument to control the flow of materials into and out of the first and second reaction columns 1 and 2. Manual valves are used to change the cross-section of a passageway and the direction of medium flow. They offer functions such as diversion, shutoff, regulation, throttling, check, diversion, or overflow pressure relief. They are low-cost and convenient for personnel to adjust the flow of materials transported within pipelines.

[0038] Furthermore, the first reaction column 1 further includes a first adsorption column, and the second reaction column 2 further includes a second adsorption column.

[0039] The first reaction column 1 can also be a first adsorption column, and the second reaction column 2 can also be a second adsorption column. The effects of the first reaction column 1 and the second reaction column 2 used in this embodiment are: the by-product dichlorosilane is added with excess silicon tetrachloride in the reaction column, and the raw material trichlorosilane is generated through an anti-disproportionation reaction. If the first reaction column 1 is replaced with a first adsorption column and the second reaction column 2 is replaced with a second adsorption column, the adsorption column is used to reduce the residual pollutants. Compared with the reaction column, both are used to treat dichlorosilane. Therefore, either one can be used.

[0040] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. The embodiments and features of the embodiments of this application may be combined arbitrarily without conflict. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A deproportionation system for polysilicon production, characterized in that: include: a first reaction column, the first reaction column having a first opening and a first outlet, a first connecting pipe communicating with the first opening and the first outlet, a first valve group being provided on the first connecting pipe, and a feed pipe being connected to the first connecting pipe; A second reaction column, wherein the second reaction column has a second opening and a second outlet, a second connecting pipe is provided between the second opening and the second outlet, a second valve group is provided on the second connecting pipe, and a discharge pipe is connected to the second connecting pipe; a first connecting pipe and a second connecting pipe are provided between the first connecting pipe and the second connecting pipe respectively, the first connecting pipe is close to the feed pipe, and the second connecting pipe is close to the discharge pipe; a connecting valve is provided on the first connecting pipe.

2. The anti-disproportionation system for polysilicon production according to claim 1, characterized in that: The first valve group includes a first valve, a second valve, a third valve, a fourth valve and a fifth valve sequentially distributed on the first connecting pipe, the first valve is located at the first opening, and the fifth valve is located at the first outlet; the connection between the feed pipe and the first connecting pipe is located between the second valve and the third valve; the connection between the first connecting pipe and the first connecting pipe is located between the first valve and the second valve, and the connection between the second connecting pipe and the first connecting pipe is located between the fourth valve and the fifth valve.

3. The anti-disproportionation system for polysilicon production according to claim 2, characterized in that: The second valve group includes a sixth valve, a seventh valve, an eighth valve, a ninth valve and a tenth valve sequentially distributed on the second connecting pipe, the sixth valve is located at the second opening, and the seventh valve is located at the second outlet; the connection between the discharge pipe and the second connecting pipe is located between the eighth valve and the ninth valve; the connection between the second connecting pipe and the first connecting pipe is located between the sixth valve and the seventh valve, and the connection between the second connecting pipe and the second connecting pipe is located between the ninth valve and the tenth valve.

4. The anti-disproportionation system for polysilicon production according to claim 3, characterized in that: The first valve, the fifth valve, the sixth valve, the tenth valve and the connecting valve are all cut-off valves, and the second valve, the third valve, the fourth valve, the seventh valve, the eighth valve, the ninth valve and the tenth valve are all manual valves.

5. The anti-disproportionation system for polysilicon production according to claim 4, characterized in that: The first reaction column further includes a first adsorption column, and the second reaction column further includes a second adsorption column.

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