Fluidized bed reactor for polycrystalline silicon production

Abstract

The utility model relates to the technical field of polycrystalline silicon production, in particular to a fluidized bed reactor for polycrystalline silicon production, which comprises a barrel, a gas distributor, a bubble breaking plate I, a flow guide bundle and a control system, a reaction cavity is formed in the cylinder body; the gas distributor is arranged at the bottom of the barrel; a supporting seat is arranged in the cylinder body; the plurality of foam breaking plates I are distributed on different layers of supporting seats; the foam breaking plate I can move up and down in a preset range relative to the U-shaped opening; the flow guide bundle is arranged in the cylinder body and is positioned above the bubble breaking plate I; a second bubble breaking plate is arranged between every two adjacent stages of flow guide beams; the second bubble breaking plate is attached to the two adjacent stages of flow guide beams; the control system comprises a pressure sensor and a flow regulating valve; the pressure sensor is arranged in the cylinder body; and the flow regulating valve is arranged at the gas phase inlet. According to the utility model, by optimizing the internal structure of the reactor, the problem of silicon powder blockage is solved, the conversion rate of trichlorosilane is increased, and energy conservation and consumption reduction are realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to polycrystal silicon production technical field especially relates to a fluidized bed reactor for polycrystal silicon production. BACKGROUND

[0002] In polycrystal silicon production, the by-product silicon tetrachloride (SiCl4) is converted into trichlorosilane (SiHCl3) with metallurgical grade silicon (MG-Si) and hydrogen (H2) in a fluidized bed reactor in the cold hydrogenation process. In the prior art, there are mainly two kinds of flow guide modes in the fluidized bed:

[0003] Bubble breaker flow guide: the conversion rate is improved by prolonging the gas-solid contact time. However, with the extension of the running time, silicon powder accumulation is easily formed in the fluidized bed, the bubble breaker plate is blocked, and the silicon powder cannot be added, which seriously affects the stable operation of the system;

[0004] Flow guide beam flow guide: avoids silicon powder blockage, but the gas-solid contact time is insufficient, the conversion rate is low, and the production cost is high.

[0005] Both of the above two methods have significant defects, which restrict the efficiency and economy of polycrystal silicon production. INVENTION CONTENTS

[0006] Therefore, the utility model provides a fluidized bed reactor for polycrystal silicon production, the main purpose is to solve the problem of silicon powder blockage under low investment cost by optimizing the internal structure of the fluidized bed reactor, and to improve the conversion rate of trichlorosilane, realize energy saving and consumption reduction.

[0007] In order to achieve the above purpose, the utility model mainly provides the following technical scheme:

[0008] The embodiment of the utility model provides a fluidized bed reactor for polycrystal silicon production, which comprises: a cylinder, a gas distributor, a bubble breaker plate, a flow guide beam and a control system.

[0009] The cylinder is formed with a reaction cavity;

[0010] The bottom of the cylinder has a gas inlet; the gas inlet is communicated with the reaction cavity;

[0011] The side of the cylinder has a silicon powder inlet; the silicon powder inlet is communicated with the reaction cavity;

[0012] The top of the cylinder has a material outlet; the material outlet is communicated with the reaction cavity;

[0013] The gas distributor is arranged at the bottom of the cylinder, at the downstream side of the gas inlet, and comprises a distribution plate and a plurality of nozzles, the distribution plate separates the reaction cavity into a gas inlet chamber and a reaction chamber, the nozzles are arranged on the distribution plate and are configured to spray the gas in the gas inlet chamber towards the reaction chamber.

[0014] The cylinder is fixedly provided with support seats, the support seats are distributed in multiple layers, each layer of the support seats is provided in a plurality of, and each layer of the support seats is arranged in an array along a circumferential direction, one side of each support seat is provided with a U-shaped opening, and the U-shaped openings are distributed along a radial direction of the cylinder.

[0015] A plurality of first bubble breaking plates are arranged on different layers of the support seats and are clamped and limited by the U-shaped openings, and the first bubble breaking plates can move up and down within a predetermined range relative to the U-shaped openings.

[0016] The flow guide beams are detachably arranged in the cylinder and are located above the first bubble breaking plates, the flow guide beams are multi-stage, and flow guide channels of adjacent two stages of the flow guide beams are coaxially distributed one by one.

[0017] A second bubble breaking plate is arranged between adjacent two stages of the flow guide beams, and the second bubble breaking plate is arranged in abutment with the adjacent two stages of the flow guide beams.

[0018] The control system comprises a pressure sensor and a flow regulating valve, the pressure sensor is arranged in the cylinder and is used for monitoring the pressure in the cylinder.

[0019] The flow regulating valve is arranged at the gas inlet and is used for adjusting the flow rate of the gas.

[0020] Further, long strip-shaped mesh holes are arranged on the first bubble breaking plate, and the long strip-shaped mesh holes extend along a radial direction of the first bubble breaking plate.

[0021] Further, circular mesh holes are arranged on the second bubble breaking plate, and the circular mesh holes are uniformly distributed.

[0022] By means of the above technical scheme, the fluidized bed reactor for polysilicon production at least has the following advantages:

[0023] By optimizing the internal structure of the fluidized bed reactor, the problem of silicon powder blockage is solved at low investment cost, the conversion rate of trichlorosilane is improved, and energy saving and consumption reduction are realized.

[0024] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and the content of the specification can be implemented, the following is a preferred embodiment of the present application and the detailed description of the drawings. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a fluidized bed reactor for polycrystalline silicon production, provided as an embodiment of the present invention.

[0026] As shown in the figure:

[0027] 1 is the cylinder body, 1-1 is the gas phase inlet, 1-2 is the silicon powder inlet, 2 is the gas distributor, 3 is the first bubble-breaking plate, 4 is the flow guide, 5 is the second bubble-breaking plate, 6 is the flow regulating valve, 7 is the support base, and 8 is the pressure sensor. Detailed Implementation

[0028] To further illustrate the technical means and effects adopted by this utility model to achieve its intended purpose, the specific implementation methods, structures, features, and effects according to this utility model application are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0029] like Figure 1 As shown in the figure, an embodiment of this utility model discloses a fluidized bed reactor for polycrystalline silicon production, comprising: a cylindrical body 1, a gas distributor 2, a bubble-breaking plate 3, a flow guide 4, and a control system; a reaction chamber is formed inside the cylindrical body 1; a gas phase inlet 1-1 is located at the bottom of the cylindrical body 1, and the gas phase inlet 1-1 is connected to the reaction chamber for the introduction of silicon tetrachloride and hydrogen. A silicon powder inlet 1-2 is located on the side of the cylindrical body 1, and the silicon powder inlet 1-2 is connected to the reaction chamber; a flow control valve is installed at the silicon powder inlet 1-2 to control the amount of silicon powder entering, and the flow control valve is connected to the control system to actively coordinate the entry of gas and silicon powder, so as to match the flow rate and effectively prevent blockage. A material outlet is located at the top of the cylindrical body 1, and the material outlet is connected to the reaction chamber for the output of the material after the reaction.

[0030] Gas distributor 2 is located at the bottom of cylinder 1; downstream of gas inlet 1-1; gas distributor 2 includes: distribution plate and nozzles, the distribution plate divides the reaction chamber into an inlet chamber and a reaction chamber; there are multiple nozzles, the nozzles pass through the distribution plate, and the nozzles are configured to spray the gas in the inlet chamber to the reaction chamber.

[0031] The support seat 7 is fixedly arranged in the barrel 1; the support seat 7 is distributed in multiple layers; the number of layers of the support seat 7 can be set according to requirements, and preferably 3-6 layers are set to avoid blockage. The single-layer support seat 7 is multiple; the single-layer support seat 7 is arranged in an array along the circumferential direction; preferably, the single-layer support seat 7 is 3-4; one side of the support seat 7 has a 'U'-shaped opening; the 'U'-shaped opening is distributed along the radial direction of the barrel 1. The bubble breaking plate one 3 is multiple; the multiple bubble breaking plate one 3 is distributed on the support seat 7 of different layers and is clamped and limited by the 'U'-shaped opening to prolong the gas-solid reaction time. Preferably, the bubble breaking plate one 3 is distributed with a long-strip-shaped mesh; the long-strip-shaped mesh extends along the radial direction of the bubble breaking plate one 3, the long-strip-shaped mesh can improve the passing property and can appropriately change the airflow direction between the adjacent two layers of bubble breaking plate one 3, has a certain disturbance effect on the airflow and increases the contact opportunity of the airflow and the silicon powder. The bubble breaking plate one 3 can move up and down in a predetermined range relative to the 'U'-shaped opening, can make the bubble breaking plate one 3 appropriately act when the airflow fluctuates, and preferably avoid blockage.

[0032] The guide beam 4 is detachably arranged in the barrel 1 and located above the bubble breaking plate one 3; the guide beam 4 is multiple stages; the guide channels of the adjacent two stages of guide beams 4 are coaxially distributed in correspondence with each other; the multiple-stage guide beam 4 design ensures that the silicon powder is uniformly dispersed and continuously discharged and avoids local accumulation. The bubble breaking plate two 5 is arranged between the adjacent two stages of guide beams 4; the bubble breaking plate two 5 is arranged in close contact with the adjacent two stages of guide beams 4; the bubble breaking plate two 5 slows down the falling speed of the silicon powder and prolongs the gas-solid contact time. Preferably, the bubble breaking plate two 5 is distributed with a circular mesh; the circular mesh is uniformly distributed to stabilize the airflow between the adjacent two stages of guide beams 4.

[0033] The control system: including a pressure sensor 8 and a flow regulating valve 6; the pressure sensor 8 is arranged in the barrel 1 and is used for monitoring the pressure in the barrel 1; the pressure sensor 8 is multiple; the multiple pressure sensors 8 are respectively arranged at different heights to monitor the pressure change. The flow regulating valve 6 is arranged at the gas inlet 1-1 and is used for adjusting the gas flow rate; in combination with the pressure sensor 8 and the flow regulating valve 6, the silicon powder state in the fluidized bed is evaluated in real time, and the conversion rate and the blockage risk are balanced.

[0034] One embodiment of the utility model discloses a kind of fluidized bed reactors for polysilicon production, by optimizing the internal structure of fluidized bed reactor, solve silicon powder blockage problem under low investment cost, while improve trichlorosilane conversion rate, realize energy saving and cost reduction.

[0035] One embodiment of the utility model discloses a kind of fluidized bed reactors for polysilicon production, continuous operation has been 12 months, silicon powder is discharged smoothly, average single set daily average production trichlorosilane 300 tons or so, significantly improve production efficiency, and reduce operation and maintenance cost, with extensive popularization value.

[0036] Further, it will be appreciated that, as used herein, the terminology or description "first", "second", and / or the like, are not intended to limit the scope of the example embodiments or the appended claims to only a single iteration of the elements being described but are used to distinguish between two separate, distinct, and independent elements or steps in the process of the example embodiments. In addition, the use of "first", "second", and / or the like are not meant to indicate that the elements so designated can only be used in a single category of implementations and are used herein merely to provide a consistent system and methodology when discussing the example embodiments. As such, the use of "first", "second", and / or the like in the description or claims is not to be understood as indicating that a particular element must be used before or after another element in some order.

[0037] In the description of the present application, unless specifically defined and limited otherwise, the terms "mounting", "connecting", "connecting", "fixing" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] The standard parts used in the present application can be purchased from the market, and the special-shaped parts can be ordered according to the description and the drawings, and the specific connection mode of each part adopts the conventional means such as bolts, rivets and welding in the prior art, and the mechanical parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection mode in the prior art, which will not be described in detail here.

[0039] The above is only a preferred embodiment of the present application, and does not limit the present application in any form, and any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the present application still belongs to the scope of the technical scheme of the present application.

Claims

1. A fluidized bed reactor for polysilicon production, characterized in that, It comprises a cylinder, a gas distributor, a bubble breaker, a flow guide beam and a control system. A reaction cavity is formed in the cylinder. The bottom of the cylinder is provided with a gas inlet, which is communicated with the reaction cavity. The side of the cylinder is provided with a silicon powder inlet, which is communicated with the reaction cavity. The top of the cylinder is provided with a material outlet, which is communicated with the reaction cavity. The gas distributor is arranged at the bottom of the cylinder. The gas distributor is arranged at the downstream side of the gas inlet and comprises a distribution plate and a plurality of nozzles. The distribution plate separates the reaction cavity into a gas inlet chamber and a reaction chamber. The nozzles are arranged on the distribution plate and are configured to spray the gas in the gas inlet chamber into the reaction chamber. A plurality of support seats are fixedly arranged in the cylinder. The support seats are arranged in multiple layers. Each layer of the support seats is arranged in the circumferential direction. The support seats are provided with "U"-shaped openings on one side. The "U"-shaped openings are distributed along the radial direction of the cylinder. A plurality of bubble breakers are arranged on different layers of the support seats and are limited by the "U"-shaped openings. The bubble breakers can move up and down within a predetermined range relative to the "U"-shaped openings. The flow guide beam is detachably arranged above the bubble breakers in the cylinder. The flow guide beam comprises multiple stages. The flow guide channels of adjacent two stages of the flow guide beam are coaxially arranged. A bubble breaker is arranged between adjacent two stages of the flow guide beam. The control system comprises a pressure sensor and a flow regulating valve. The pressure sensor is arranged in the cylinder to monitor the pressure in the cylinder. The flow regulating valve is arranged at the gas inlet to regulate the flow rate of the gas.

2. The fluidized bed reactor for polysilicon production according to claim 1, wherein the bubble breakers are provided with long strip-shaped mesh holes extending along the radial direction of the bubble breakers.

3. The fluidized bed reactor for polysilicon production according to claim 1, wherein the bubble breakers are provided with circular mesh holes which are uniformly distributed.

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