Polycrystalline silicon production heat source utilization system

Abstract

The utility model provides a heat source utilization system for polycrystalline silicon production, and relates to the technical field of polycrystalline silicon. The device comprises a tail gas treatment circulating pipeline, a silicon powder filter is arranged on the tail gas treatment circulating pipeline, the tail gas treatment circulating pipeline is communicated with a reduction furnace, tail gas of the reduction furnace is fed into the tail gas treatment circulating pipeline to be treated and then fed back to the reduction furnace, the tail gas treatment circulating pipeline is communicated with a heat exchange pipeline, and the heat exchange pipeline is communicated with a heat exchanger. The heat exchange pipeline passes through a rectification reboiler, two ends of the heat exchange pipeline are communicated with a tail gas treatment circulating pipeline, and tail gas in the tail gas treatment circulating pipeline passes through a silicon powder filter and then passes through the heat exchange pipeline. The heat in the tail gas of the reduction furnace is utilized, so that the electric power cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to polycrystal silicon technical field, concretely relates to a polycrystal silicon production heat source utilization system. BACKGROUND

[0002] Polycrystal silicon is a form of elemental silicon, mainly by dry hydrogen chloride gas, dry silicon powder is chlorinated under certain conditions, through condensation, rectification, reduction is made, according to the application field, polycrystal silicon can be divided into electronic grade polycrystal silicon, solar polycrystal silicon, metallurgical grade polycrystal silicon etc.

[0003] In prior art, a large amount of electric energy is needed in polycrystal silicon production process, especially in reduction link, and the power cost accounts for a large proportion. UTILITY MODEL CONTENT

[0004] The utility model aims at developing a polycrystal silicon production heat source utilization system using the heat in the tail gas of reduction furnace, so that the power cost is reduced.

[0005] The utility model realizes the following technical scheme:

[0006] A polycrystal silicon production heat source utilization system, comprising:

[0007] Tail gas treatment circulating pipeline;

[0008] Silicon powder filter, which is arranged on the tail gas treatment circulating pipeline;

[0009] Wherein, the tail gas treatment circulating pipeline is communicated with the reduction furnace, and the tail gas of the reduction furnace is sent back to the reduction furnace after being treated in the tail gas treatment circulating pipeline;

[0010] The tail gas treatment circulating pipeline is communicated with a heat exchange pipeline, the heat exchange pipeline passes through a rectification reboiler, and the two ends of the heat exchange pipeline are communicated with the tail gas treatment circulating pipeline;

[0011] The tail gas in the tail gas treatment circulating pipeline first passes through the silicon powder filter and then passes through the heat exchange pipeline.

[0012] Optionally, a first valve is arranged on the heat exchange pipeline at the inlet side of the rectification reboiler.

[0013] Optionally, a second valve is arranged on the tail gas treatment circulating pipeline between the two communication positions of the heat exchange pipeline and the tail gas treatment circulating pipeline.

[0014] Optionally, a recovery condensing unit and an adsorption column are arranged on the tail gas treatment circulating pipeline, and the recovery condensing unit and the adsorption column are sequentially arranged according to the flow direction of the tail gas in the tail gas treatment circulating pipeline.

[0015] Optionally, the two communication positions of the heat exchange pipeline and the tail gas treatment circulation pipeline are located between the silicon powder filter and the recovery condensing unit.

[0016] Optionally, the silicon powder filter comprises a tank body, a cylindrical filter core is arranged in the tank body, an air outlet pipe is arranged on the tank body and communicates with the internal closed area of the filter core, and an air inlet pipe is communicated with the tank body.

[0017] Optionally, the air inlet pipe and the air outlet pipe are respectively communicated with a back flushing discharge pipe and a back flushing inlet pipe near one side of the tank body, and valves are arranged on the back flushing discharge pipe and the back flushing inlet pipe.

[0018] Optionally, pressure gauges are arranged on the air inlet pipe and the air outlet pipe.

[0019] Optionally, an elastic connecting elastic pipe is arranged on the top of the filter core, the connecting elastic pipe is connected with the top of the tank body, a hose is arranged in the connecting elastic pipe, and the two ends of the hose are respectively communicated with the internal filter core and the air outlet pipe, and a vibration motor is arranged on the top of the filter core.

[0020] Optionally, a rubber sleeve seal is arranged outside the vibration motor.

[0021] The beneficial effects of the present application are as follows:

[0022] The present application can utilize the heat in the tail gas, reduce the power consumption required for heating in the rectification section, and after the heat in the tail gas is consumed by the rectification section, the temperature is reduced to about 150 DEG C, which reduces the cooling medium required for subsequent condensation and avoids damage or leakage of the condensation system caused by high temperature, and the micro vibration motor arranged on the silicon powder filter can vibrate the filter core when back flushing the filter core, thereby improving the cleaning effect and efficiency of the silicon powder on the filter core. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required to be used in the embodiments or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The present application is a structural diagram;

[0025] Figure 2 The present application is a structural diagram of a silicon powder filter.

[0026] The drawings are as follows: 1, tank body; 2, filter core; 3, micro vibration motor; 4, air outlet pipe; 5, back flushing inlet pipe; 6, discharge pipe; 7, air inlet pipe; 8, back flushing discharge pipe; 9, first valve; 10, second valve. DETAILED DESCRIPTION

[0027] In the following, certain example embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the drawings and the description are considered to be exemplary in nature and not limiting.

[0028] In the present invention, unless explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection, or communication; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0029] The embodiments of the present application will be described in detail below with reference to the drawings.

[0030] As shown in Figure 1 and Figure 2 The utility model discloses a polycrystal silicon production heat source utilization system, including tail gas treatment circulating pipeline, both ends all intercommunication in reduction furnace, and the tail gas of reduction furnace output enters tail gas treatment circulating pipeline, and after removing silicon powder and chlorosilane in tail gas, hydrogen is sent back to reduction furnace.

[0031] Silicon powder filter, recovery condensing unit, adsorption column are sequentially arranged on tail gas treatment circulating pipeline, and the second valve 10 is arranged on the tail gas treatment circulating pipeline between the silicon powder filter and the recovery condensing unit.

[0032] The heat exchange pipeline is further communicated on the tail gas treatment circulating pipeline between the silicon powder filter and the recovery condensing unit, and the two ends of the heat exchange pipeline are communicated with the tail gas treatment circulating pipeline on the two sides of the second valve 10 respectively.

[0033] The silicon powder filter includes a tank body 1, the tank body 1 is provided with a discharge pipe 6 at the bottom, and the discharge pipe 6 is provided with a plug valve. A cylindrical filter core 2 is arranged in the tank body 1, and a connecting elastic pipe is arranged at the top of the filter core 2. The connecting elastic pipe is connected with the top of the tank body 1, and is made of elastic material, which can be rubber. The filter core 2 is fixed and can be elastically swung in the tank body 1 through the connecting elastic pipe.

[0034] The tank body 1 is provided with an air outlet pipe 4 at the top, and a hose is arranged in the connecting elastic pipe. The two ends of the hose are communicated with the inside of the filter core 2 and the air outlet pipe 4 respectively. The filter core 2 is of a closed structure, and the gas in the tank body 1 can only pass through the filter core 2 into the hose and the air outlet pipe 4. A micro vibration motor 3 is arranged at the top of the filter core 2, and a rubber sleeve is arranged outside the micro vibration motor 3 for sealing.

[0035] The side of the tank body 1 is communicated with the air inlet pipe 7, and the air inlet pipe 7 and the air outlet pipe 4 are both provided with valves. The air inlet pipe 7 and the air outlet pipe 4 are respectively communicated with the back flushing exhaust pipe 8 and the back flushing inlet pipe 5 near the side of the tank body 1, and the back flushing exhaust pipe 8 and the back flushing inlet pipe 5 are both provided with valves. The air inlet pipe 7 and the air outlet pipe 4 are both provided with pressure gauges. By comparing the pressure difference between the air inlet pipe 7 and the air outlet pipe 4, it can be determined whether the filter element 2 needs to be cleaned.

[0036] When the silicon powder filter is filtering, the valves of the back flushing exhaust pipe 8 and the back flushing inlet pipe 5 are closed, and the valves of the air inlet pipe 7 and the air outlet pipe 4 are opened. The tail gas enters the tank body 1 from the air inlet pipe 7, and the tail gas passes through the filter element 2 to achieve filtering. The silicon powder is trapped on the outer wall of the tank body 1 and the filter element 2, and the filtered tail gas is output through the hose and the air outlet pipe 4. When back flushing, the valves of the air inlet pipe 7 and the air outlet pipe 4 are closed, and the valves of the back flushing exhaust pipe 8 and the back flushing inlet pipe 5 are opened. The micro vibration motor 3 operates to vibrate the filter element 2. The back flushing inlet pipe 5 blows gas into the filter element 2. The gas passes through the filter element 2 into the tank body 1 and is then output from the back flushing exhaust pipe 8. The silicon powder on the filter element 2 is blown off. The vibration of the filter element 2 accelerates the shaking off of the attached silicon powder to separate it from the filter element 2, improving the cleaning effect and efficiency of the filter element 2, reducing the back flushing time, and allowing the silicon powder filter to resume operation as soon as possible.

[0037] The heat exchange pipeline passes through the rectifying reboiler, and the heat exchange pipeline on the inlet side of the rectifying reboiler is provided with a first valve 9.

[0038] The tail gas output from the reduction furnace is about 570℃. The tail gas contains hydrogen, silicon powder and chlorosilane. After the tail gas enters the tail gas treatment circulating pipeline, it is first filtered by the silicon powder filter to remove the silicon powder in the tail gas. The first valve 9 is opened, and the second valve 10 is closed. The tail gas output from the silicon powder filter enters the heat exchange pipeline and passes through the rectifying reboiler. In the rectifying reboiler, the heat in the tail gas is utilized. The tail gas output from the rectifying reboiler has a temperature of about 150℃. The tail gas then enters the recovery condensing unit. The tail gas is cooled using circulating water, 7℃, -10℃, -40℃ and -70℃ media. The chlorosilane in the tail gas is condensed and recovered. The tail gas then enters the adsorption column for impurity adsorption treatment. The adsorption material in the adsorption column is activated carbon. The remaining hydrogen is then sent back to the reduction furnace through the tail gas treatment circulating pipeline.

[0039] When the rectifying reboiler does not require a heat source, the first valve 9 is closed, and the second valve 10 is opened. This allows the tail gas to be sent directly to the recovery condensing unit without passing through the heat exchange pipeline. At this time, the amount of heat exchange medium used in the recovery condensing unit is increased. When the tail gas flow is too large or the heat source required by the rectifying reboiler is small, the opening of the first valve 9 and the second valve 10 is adjusted. This allows part of the tail gas to enter the heat exchange pipeline, and the other part of the tail gas to enter the recovery condensing unit directly.

[0040] The utility model discloses can utilize the heat in tail gas, reduce the power consumption needed for heating rectification section, and after the heat in tail gas is consumed by rectification section, temperature falls to about 150 DEG C, both reduce the cooling medium needed for subsequent condensation, avoid the damage or leakage of condensing system caused by high temperature, and the micro vibration motor 3 of silicon powder filter setting can vibrate filter core 2 when back flushing filter core 2, improve the cleaning effect and cleaning efficiency of silicon powder on filter core 2.

[0041] The above examples are only preferred embodiments of the utility model, and are not a limitation on the technical scheme of the utility model, and as long as the technical scheme can be realized on the basis of the above examples without creative labor, it should be considered to fall into the protection scope of the utility model patent.

Claims

1. A heat source utilization system for polycrystalline silicon production, characterized in that, The application relates to a tail gas treatment circulating pipeline, a silicon powder filter arranged on the tail gas treatment circulating pipeline, and a reducing furnace. The tail gas treatment circulating pipeline is connected with the reducing furnace, and the tail gas of the reducing furnace is sent back to the reducing furnace after being treated in the tail gas treatment circulating pipeline. The tail gas treatment circulating pipeline is connected with a heat exchange pipeline, the heat exchange pipeline passes through a rectifying reboiler, and the two ends of the heat exchange pipeline are connected with the tail gas treatment circulating pipeline. The tail gas in the tail gas treatment circulating pipeline passes through the silicon powder filter and then the heat exchange pipeline. A first valve is arranged on the heat exchange pipeline at the inlet side of the rectifying reboiler. A second valve is arranged on the tail gas treatment circulating pipeline between the two connecting positions of the heat exchange pipeline and the tail gas treatment circulating pipeline.

2. The polysilicon production heat source utilization system according to claim 1, characterized by, A recovery condensing unit and an adsorption column are arranged on the tail gas treatment circulating pipeline, and the recovery condensing unit and the adsorption column are sequentially arranged according to the flow direction of the tail gas in the tail gas treatment circulating pipeline.

3. The polysilicon production heat source utilization system according to claim 2, characterized by, The two connecting positions of the heat exchange pipeline and the tail gas treatment circulating pipeline are located between the silicon powder filter and the recovery condensing unit.

4. The polysilicon production heat source utilization system according to claim 1, characterized by The silicon powder filter comprises a tank body, a cylindrical filter core arranged in the tank body, an air outlet pipe arranged on the tank body and connected with the internal closed area of the filter core, and an air inlet pipe arranged on the tank body.

5. The polysilicon production heat source utilization system according to claim 4, characterized by The air inlet pipe and the air outlet pipe are respectively connected with a back flushing discharge pipe and a back flushing inlet pipe near one side of the tank body, and valves are arranged on the back flushing discharge pipe and the back flushing inlet pipe.

6. The polysilicon production heat source utilization system according to any one of claims 1 to 5, characterized by Pressure gauges are arranged on the air inlet pipe and the air outlet pipe.

7. The polysilicon production heat source utilization system according to claim 6, characterized by An elastic connecting elastic pipe is arranged on the top of the filter core, the connecting elastic pipe is connected with the top of the tank body, a hose is arranged in the connecting elastic pipe, and the two ends of the hose are respectively connected with the internal part of the filter core and the air outlet pipe.

8. The polysilicon production heat source utilization system according to claim 7, wherein A vibrating motor is arranged on the top of the filter core.

9. The polysilicon production heat source utilization system according to claim 8, characterized by A rubber sleeve is arranged outside the vibrating motor.

10. The polysilicon production heat source utilization system according to claim 9, wherein ​

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