Trichlorosilane make-up process for distillation column

Abstract

The application discloses a trichlorosilane supplement method for a rectifying tower, and relates to the technical field of polysilicon rectification, and comprises the following steps: S1, setting the required content of trichlorosilane in a rectifying raw material storage tank in a DCS control system; S2, generating the trichlorosilane supplement flow rate of the supplement storage tank to the rectifying raw material storage tank according to the set required content of trichlorosilane, the flow rate of the hydrogenation liquid supplemented in the rectifying raw material storage tank and the flow rate of the system circulating material supplemented in the rectifying raw material storage tank; S3, outputting the generated trichlorosilane supplement flow rate to the pump outlet flow rate setting value of the flow meter I between the supplement storage tank and the rectifying raw material storage tank; and S4, controlling the flow rate regulating valve I between the supplement storage tank and the rectifying raw material storage tank to move and regulating the value of the flow meter I to the pump outlet flow rate setting value, so that the trichlorosilane in the supplement storage tank is accurately transported into the rectifying raw material storage tank, and the accurate stability of the supplement flow rate is realized.

Description

Technical Field

[0001] This invention relates to the field of polycrystalline silicon distillation technology, and more specifically to a method for replenishing trichlorosilane in a distillation column. Background Technology

[0002] Trichlorosilane is an inorganic compound with the chemical formula SiHCl3. It is a colorless liquid, soluble in most organic solvents such as benzene, diethyl ether, and heptane. In the polysilicon industry, it is mainly used as a raw material for the production of semiconductor silicon, monocrystalline silicon, and polycrystalline silicon.

[0003] During the shutdown and maintenance of polysilicon cold hydrogenation and when the output of the distillation column is insufficient, it is necessary to continuously replenish trichlorosilane into the distillation feedstock storage tank. The purpose of replenishing trichlorosilane is to ensure the output of refined trichlorosilane separated by the distillation column, so as to meet the raw material requirements for the reduction production of polysilicon.

[0004] In the existing technology, a transfer pump is used to transfer trichlorosilane to a distillation feed tank, which then transports it to the distillation column. The transfer pump is started by on-site operators, and the flow rate is controlled by a manual valve. The flow rate control is unstable and requires frequent adjustments, which causes fluctuations in the transfer flow rate and affects the trichlorosilane content in the distillation feed tank. This, in turn, affects the operation of the distillation column, resulting in large temperature variations in the distillation column, significant loss of light component products from the bottom of the column, and impacts the quality of the bottom product and the yield of the top product. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology, this invention discloses a method for replenishing trichlorosilane in a distillation column. The purpose of this invention is to solve the problem in the existing technology where the feed pump is started by on-site operators and controlled by manual valves, resulting in unstable flow control and the need for frequent adjustments, which in turn affects the operation of the distillation column. This invention mainly utilizes the control logic and corresponding calculation logic of a DCS control system to achieve automatic adjustment and control of the feed flow rate, thus achieving automatic and stable regulation of the feed flow rate.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for replenishing trichlorosilane in a distillation column includes the following steps:

[0008] I. Setting the required content of TCS

[0009] S1. Set the required content of trichlorosilane in the distillation feedstock storage tank in the DCS control system;

[0010] In the above steps, the central control operator sets the required content of trichlorosilane in the distillation feedstock storage tank in the DCS control system.

[0011] DCS control system: DCS is the full name of Distributed Control System in English, and the full name in Chinese is distributed control system. Its main function is to convert the process signals (temperature, pressure, flow, liquid level, etc.) in the field into digital signals through an A / D converter (signal acquisition card), store them in the main controller, and display them to the operator through the human-machine interface. The operator can send commands to the field device through the human-machine interface, such as opening and closing valves, adjusting the speed of the frequency converter, etc. The DCS control system can also realize PID, interlocking and sequence control functions through configuration (programming).

[0012] II. Calculate the TCS supplementary flow

[0013] S2, the DCS control system generates the TCS supplementary flow from the supplementary material storage tank to the distillation raw material storage tank according to the set TCS demand content, the hydrogenation liquid flow supplemented in the distillation raw material storage tank, and the system circulating material flow supplemented in the distillation raw material storage tank.

[0014] Preferably, a flowmeter I is arranged on the pipeline between the supplementary material storage tank and the distillation raw material storage tank, and the distillation raw material storage tank is further connected with a hydrogenation liquid supplement pipeline and a system circulating material supplement pipeline, and a flowmeter II and a flowmeter III are arranged on the hydrogenation liquid supplement pipeline and the system circulating material supplement pipeline, respectively.

[0015] In the above steps, the hydrogenation liquid is transported to the distillation raw material storage tank, and the transported hydrogenation liquid is the crude TCS produced by cold hydrogenation for separation and purification in the distillation column.

[0016] The system circulating material is transported to the distillation raw material storage tank, and the system circulating material refers to the excess refined TCS separated by the distillation column and the material produced by the impurity removal process of the distillation column. The purpose of transporting the system circulating material to the distillation raw material storage tank is to enter the distillation column again for separation and purification, so as to achieve the recycling of the material.

[0017] Preferably, in the S2 step, the content of TCS in the distillation raw material storage tank is:

[0018]

[0019] Wherein, TCS is trichlorosilane.

[0020] In the present application, the purpose of calculating the content of TCS in the distillation raw material storage tank is to monitor the content of TCS in the distillation raw material storage tank in real time.

[0021] Preferably, in the S2 step, the flow of the flowmeter I is the TCS supplementary flow from the supplementary material storage tank to the distillation raw material storage tank, and the flow of the flowmeter I is:

[0022]

[0023] TCS is trichlorosilane.

[0024] The relationship between the content calculation formula of trichlorosilane in the rectification raw material tank and the flow calculation formula of flowmeter I is that the "set TCS content" in the second formula is the "TCS content in the rectification raw material tank" in the first formula, which is equivalent to the "TCS content in the rectification raw material tank" in the first formula as a known quantity (the required content set by the operator), and the "flowmeter I flow" is an unknown quantity, which is used to transform the first formula to obtain the "flowmeter I flow", that is, the flow of trichlorosilane to be supplemented.

[0025] Preferably, in the S2 step, after generating the trichlorosilane supplement flow, the generated trichlorosilane supplement flow is smoothed and filtered by using a filtering module.

[0026] In the present application, the flow of the material to be supplemented is calculated by using a formula, in order to prevent the flow from fluctuating sharply, a filtering function block is added after the flow is calculated to smooth and filter the calculated instantaneous flow.

[0027] In the present application, a specific calculation program is used to calculate the content of trichlorosilane in the original rectification raw material tank, and then the required content is set to obtain the flow of trichlorosilane to be supplemented by using the calculation program. The calculated flow is processed and output by using the filtering function block and the action function block of the DCS system, so as to realize automatic adjustment and stable feeding flow.

[0028] III. The flow output is set to the pump outlet flow value

[0029] S3, the generated trichlorosilane supplement flow is output to the pump outlet flow set value of the flowmeter I between the feeding tank and the rectification raw material tank;

[0030] In the present application, the calculated flow is transmitted to the set value of the flowmeter I in the pump outlet flow control loop by using the action block, so as to accurately control the flow.

[0031] IV. The regulating valve adjusts the flow

[0032] S4, the DCS control system controls the action of the flow regulating valve I between the feeding tank and the rectification raw material tank to adjust the value of the flowmeter I to the pump outlet flow set value, so as to accurately transport the trichlorosilane in the feeding tank to the rectification raw material tank;

[0033] Preferably, a pump I, a flow meter I and a flow regulating valve I are sequentially arranged on the conveying pipeline between the make-up tank and the rectification raw material tank, the flow meter I and the flow regulating valve I are in flow indication control, and the pump I, the flow meter I and the flow regulating valve I form a pump outlet flow control loop.

[0034] In the present application, the pump I works to convey the trichlorosilane in the make-up tank to the rectification raw material tank through the flow meter I and the flow regulating valve I, and the flow regulating valve I is used to control the flow of the flow meter I during the conveying process.

[0035] Preferably, the pump outlet flow control loop is connected with a pressure control loop, the inlet of the pressure control loop is connected with the pump outlet flow control loop, the outlet is connected to the make-up tank, a flow meter IV and a backflow regulating valve I are arranged on the pressure control loop, a pressure sensor I is arranged on the pump outlet flow control loop, and the pressure sensor I and the backflow regulating valve I are in pressure indication control.

[0036] Preferably, in the S4 step, when the trichlorosilane is conveyed, the backflow regulating valve I is opened to backflow the excess material into the make-up tank.

[0037] The pressure sensor I detects the outlet pressure of the pump I in real time, and when the detected actual pressure is greater than the set pressure, the opening degree of the backflow regulating valve I is increased, and when the detected actual pressure is less than the set pressure, the opening degree of the backflow regulating valve I is decreased.

[0038] In the present application, in order to prevent the pump I from being stopped due to underload, the pump I outlet pressure and the backflow flow meter IV form a pressure control loop, the opening degree of the backflow regulating valve I is controlled by the pump outlet pressure, the pump I outlet pressure is stabilized, and the normal operation of the pump I is ensured.

[0039] In the present application, the pump outlet pressure and the backflow regulating valve form a pressure control loop, the pump outlet pressure is controlled by the backflow of the pump, the pump is prevented from being stopped due to underload, and the normal operation is ensured.

[0040] Five, rectification

[0041] S5, conveying the material in the rectification raw material tank to the rectification tower, and conveying the rectified material to the downstream process after rectification by the rectification tower.

[0042] In the above steps, the cold hydrogenation product crude trichlorosilane material in the rectification raw material tank is conveyed to the rectification tower, and the refined trichlorosilane material is conveyed to the downstream process after rectification by the rectification tower to produce polycrystalline silicon products by reduction vapor deposition.

[0043] Preferably, in the S5 step, the material after rectification of the rectification tower is delivered to the downstream process by pump III, a material delivery pipeline and a material reflux pipeline are connected in parallel on the pipeline at the rear end of the pump III, and the outlet of the material reflux pipeline is connected to the make-up tank;

[0044] The flow meter VI and the flow regulating valve II are sequentially arranged on the material delivery pipeline, and the flow meter V and the reflux regulating valve II are sequentially arranged on the material reflux pipeline; the pressure sensor II is arranged on the main pipeline at the rear end of the pump III, and the pressure sensor II and the reflux regulating valve II are connected in pressure indication control.

[0045] Preferably, in the S5 step, when the rectified material is delivered, the reflux regulating valve II is opened to reflux the excess material into the make-up tank.

[0046] The pressure sensor II detects the outlet pressure of the pump III in real time, when the detected actual pressure is greater than the set pressure, the opening degree of the reflux regulating valve II is controlled to increase, and when the detected actual pressure is less than the set pressure, the opening degree of the reflux regulating valve II is controlled to decrease.

[0047] In the present application, in order to prevent the pump III from being unloaded and stopped, the pump III outlet pressure and the reflux flow meter V form a pressure control loop, the opening degree of the reflux regulating valve II is controlled by the pump outlet pressure, the pump III outlet pressure is controlled to be stable, and the normal operation of the pump III is ensured. The present application automatically divides the excess rectified refined TCS into the make-up tank to form a closed loop circulation.

[0048] In the present application, the pump outlet pressure and the reflux regulating valve are used to form a pressure control loop for the rectification tower, first to meet the demand of the downstream user, and then to automatically adjust the flow of the reflux flow meter V according to the change of the demand of the downstream user, and to automatically divide the excess output to the make-up tank to form a completely automatic closed loop circulation.

[0049] The beneficial effects of the present application are as follows:

[0050] The present application provides a rectification tower trichlorosilane supplement method, a calculation program is arranged to automatically calculate the flow of trichlorosilane to be supplemented, a DCS control loop is used to automatically control the regulating valve, the supplement flow is accurately and stably controlled, and the trichlorosilane content in the rectification raw material tank is stably ensured.

[0051] The present application provides a rectification tower trichlorosilane supplement method, a pump outlet pressure and a reflux regulating valve are used to form an automatic control loop, so that the pump can stably operate, the unloaded stop is avoided, and the full-automatic control of the device is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 The make-up control process of the present application is shown in the following table:

[0053] Figure 2 The pump operation control process of the present application is shown in the following table:

[0054] Figure 3 The schematic diagram of the trichlorosilane supplement system of the rectification tower of the present application;

[0055] Reference signs:

[0056] 1, feed storage tank; 2, rectification raw material storage tank; 3, rectification tower; 4, pump I; 5, pump II; 6, pump III; 7, flow meter I; 8, flow meter II; 9, flow meter III; 10, flow meter IV; 11, flow meter V; 12, flow meter VI; 13, flow regulating valve I; 14, reflux regulating valve I; 15, pressure sensor I; 16, flow regulating valve II; 17, reflux regulating valve II; 18, pressure sensor II. DETAILED DESCRIPTION

[0057] The concept, specific structure and generated technical effects of the present application will be described clearly and completely in combination with the embodiments and the drawings below, so as to fully understand the purposes, features and effects of the present application.

[0058] Example 1

[0059] A trichlorosilane supplement method for a rectification tower, as shown in the figure, comprises the following steps: Figure 1

[0060] S1, setting the required trichlorosilane content in the rectification raw material storage tank in the DCS control system;

[0061] S2, the DCS control system generates the trichlorosilane supplement flow rate of the feed storage tank to the rectification raw material storage tank according to the set required trichlorosilane content, the supplement hydrogenation liquid flow rate in the rectification raw material storage tank and the system circulating material flow rate in the rectification raw material storage tank;

[0062] S3, outputting the generated trichlorosilane supplement flow rate to the pump outlet flow rate set value of the flow meter I between the feed storage tank and the rectification raw material storage tank;

[0063] S4, the DCS control system controls the flow regulating valve I between the feed storage tank and the rectification raw material storage tank to adjust the value of the flow meter I to the pump outlet flow rate set value, so as to accurately deliver the trichlorosilane in the feed storage tank to the rectification raw material storage tank;

[0064] S5, delivering the material in the rectification raw material storage tank to the rectification tower, and delivering the rectification material to the downstream process after rectification by the rectification tower.

[0065] In this embodiment, a calculation program is set to automatically calculate the required trichlorosilane supplement flow rate, and the DCS control loop is used to automatically control the regulating valve, so as to realize the accurate and stable supplement flow rate and ensure the stable trichlorosilane content in the rectification raw material storage tank.

[0066] Example 2​

[0067] The embodiment is based on embodiment 1, and further describes the S1 step. In the S1 step, the control operator sets the required content of trichlorosilane in the rectification raw material tank in the DCS control system, so as to calculate the subsequent trichlorosilane supplement amount.

[0068] Embodiment 3

[0069] The embodiment is based on embodiment 2, and further describes the S2 step. As shown in the figure, a flowmeter I is arranged on the pipeline between the supplement tank and the rectification raw material tank. The rectification raw material tank is further connected with a hydrogenation liquid supplement pipeline and a system circulating material supplement pipeline. The hydrogenation liquid supplement pipeline and the system circulating material supplement pipeline are respectively provided with a flowmeter II and a flowmeter III. Figure 3 The hydrogenation liquid supplement pipeline and the system circulating material supplement pipeline are respectively provided with a flowmeter II and a flowmeter III.

[0070] In the above step, the hydrogenation liquid is transported into the rectification raw material tank. The transported hydrogenation liquid is the crude trichlorosilane produced by cold hydrogenation and used for separation and purification of the rectification tower.

[0071] The system circulating material is transported into the rectification raw material tank. The system circulating material refers to the excess refined trichlorosilane separated by the rectification tower and the material produced by the impurity removal process of the rectification tower. The purpose of transporting the system circulating material into the rectification raw material tank is to enter the rectification tower again for separation and purification, so as to achieve the recycling of the material.

[0072] In the S2 step, the content of trichlorosilane in the rectification raw material tank is:

[0073]

[0074] TCS is trichlorosilane.

[0075] In the S2 step, the flow of the flowmeter I is the supplement flow of trichlorosilane transported from the supplement tank to the rectification raw material tank. The flow of the flowmeter I is:

[0076]

[0077] TCS is trichlorosilane.

[0078] The relationship between the content calculation formula of trichlorosilane in the rectification raw material tank and the flow calculation formula of the flowmeter I is that the “set TCS content” in the second formula is the “TCS content in the rectification raw material tank” in the first formula, which is equivalent to the “TCS content in the rectification raw material tank” in the first formula as a known quantity (the required content set by the operator). The flow of the flowmeter I is the flow required to supplement TCS, which is obtained by transforming the first formula.

[0079] In the S2 step, after the trichlorosilane supplement flow is generated, the generated trichlorosilane supplement flow is subjected to a smoothing filtering process by using a filtering module.

[0080] In this embodiment, the flow of the required supplement is calculated by using a formula, and in order to prevent the flow from having a sharp fluctuation, a filtering function block is added after the flow is calculated to perform a smoothing filtering process on the calculated instantaneous flow.

[0081] In this embodiment, the content of trichlorosilane in the original rectification raw material tank is calculated by using a specific calculation program, and then by setting the required content, the flow of the required trichlorosilane supplement is obtained by using the calculation program. The calculated flow is processed and output by using the filtering function block and the action function block of the DCS system, so as to realize automatic adjustment and stable supplement flow.

[0082] Embodiment 4

[0083] This embodiment is based on embodiment 3, and the S3 step is further described. In the S3 step, the calculated flow is transmitted to the set value of the flow meter I in the pump outlet flow control loop by using the action block, so as to accurately control the flow.

[0084] Embodiment 5

[0085] This embodiment is based on embodiment 4, and the S4 step is further described. In the S4 step, as shown in the figure, the conveying pipeline between the supplement tank and the rectification raw material tank is sequentially provided with a pump I, a flow meter I and a flow regulating valve I. The flow meter I and the flow regulating valve I are flow indication control. The pump I, the flow meter I and the flow regulating valve I form a pump outlet flow control loop. Figure 3

[0086] In this embodiment, the pump I works, and the trichlorosilane in the supplement tank is conveyed to the rectification raw material tank through the flow meter I and the flow regulating valve I. In the conveying process, the flow of the flow meter I is controlled by using the flow regulating valve I.

[0087] The pump outlet flow control loop is connected with a pressure control loop. The inlet of the pressure control loop is connected with the pump outlet flow control loop, and the outlet is connected to the supplement tank. The pressure control loop is provided with a flow meter IV and a backflow regulating valve I. The pump outlet flow control loop is provided with a pressure sensor I. The pressure sensor I and the backflow regulating valve I are pressure indication control.

[0088] In the S4 step, when the trichlorosilane is conveyed, the backflow regulating valve I is opened, and the excess material is backflowed into the supplement tank.

[0089] As shown in the figure, Figure 2 ​As shown, the pressure sensor I detects the pump I outlet pressure in real time, when the detected actual pressure is greater than the set pressure, the opening of the backflow regulating valve I is increased, and when the detected actual pressure is less than the set pressure, the opening of the backflow regulating valve I is reduced.

[0090] In this embodiment, in order to prevent the pump I from being under load and stopping, the pump I outlet pressure and the backflow flowmeter IV form a pressure control loop, the opening of the backflow regulating valve I is controlled by the pump outlet pressure, the pump I outlet pressure is controlled to be stable, and the normal operation of the pump I is ensured.

[0091] In this embodiment, the pump outlet pressure and the backflow regulating valve form a pressure control loop, the pump outlet pressure is controlled by the backflow of the pump, the under load of the pump is avoided, and the normal operation is ensured.

[0092] Embodiment 6

[0093] This embodiment is based on embodiment 5, and the S5 step is further described. Figure 3 As shown, the rectified material of the rectifying tower is transported to the downstream process by the pump III, the material conveying pipeline and the material backflow pipeline are connected in parallel on the pipeline at the rear end of the pump III, and the outlet of the material backflow pipeline is connected to the material supplementing tank;

[0094] The flowmeter VI and the flow regulating valve II are sequentially arranged on the material conveying pipeline, and the flowmeter V and the backflow regulating valve II are sequentially arranged on the material backflow pipeline; the pressure sensor II is arranged on the main pipeline at the rear end of the pump III, and the pressure sensor II and the backflow regulating valve II are connected in pressure indication control.

[0095] In the S5 step, when the rectified material is transported, the backflow regulating valve II is opened, and the excess material is backflowed to the material supplementing tank.

[0096] As shown, Figure 2 The pressure sensor II detects the pump III outlet pressure in real time, when the detected actual pressure is greater than the set pressure, the opening of the backflow regulating valve II is increased, and when the detected actual pressure is less than the set pressure, the opening of the backflow regulating valve II is reduced.

[0097] In this embodiment, in order to prevent the pump III from being under load and stopping, the pump III outlet pressure and the backflow flowmeter V form a pressure control loop, the opening of the backflow regulating valve II is controlled by the pump outlet pressure, the pump III outlet pressure is controlled to be stable, and the normal operation of the pump III is ensured. The rectified excess refined TCS is automatically divided into the material supplementing tank to form a closed loop circulation.

[0098] In the embodiment, the pump outlet pressure and the reflux regulating valve are also used to form a pressure control loop for the distillation column, first to meet the downstream user demand, and according to the change of the downstream user demand, the flow of the reflux flowmeter V is automatically adjusted, and the excess output is automatically distributed to the supplementary feeding tank, forming a completely automatic closed loop circulation.

[0099] The above describes the embodiments of the present application, but the present application is not limited to the above-mentioned embodiments, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. A method for replenishing trichlorosilane in a distillation column, characterized in that, Includes the following steps: S1. Set the required content of trichlorosilane in the distillation feedstock storage tank in the DCS control system; S2, DCS control system generates the trichlorosilane replenishment flow rate from the feed tank to the distillation feed tank based on the set trichlorosilane demand content, the flow rate of the hydrogenated liquid replenished in the distillation feed tank, and the flow rate of the system circulating material replenished in the distillation feed tank. S3. The generated trichlorosilane supplement flow rate is output to the pump outlet flow rate set value of flow meter I between the feed tank and the distillation raw material tank; S4, DCS control system controls the flow regulating valve I between the feed tank and the distillation feed tank to adjust the value of flow meter I to the pump outlet flow set value, so as to accurately deliver the trichlorosilane in the feed tank to the distillation feed tank; S5. The material in the distillation raw material storage tank is transported to the distillation column, and after distillation in the distillation column, the distilled material is transported to the downstream process.

2. The method for replenishing trichlorosilane in a distillation column as described in claim 1, characterized in that, A flow meter I is installed on the pipeline between the feed tank and the distillation feed tank. The distillation feed tank is also connected to a hydrogenated liquid replenishment pipeline and a system circulating material replenishment pipeline. A flow meter II and a flow meter III are respectively installed on the hydrogenated liquid replenishment pipeline and the system circulating material replenishment pipeline.

3. The method for replenishing trichlorosilane in a distillation column as described in claim 2, characterized in that, In step S2, the content of trichlorosilane in the distillation feed storage tank is: TCS stands for trichlorosilane.

4. The method for replenishing trichlorosilane in a distillation column as described in claim 3, characterized in that, In step S2, the flow rate of flow meter I is the replenishment flow rate of trichlorosilane supplied from the feed tank to the distillation feed tank. The flow rate of flow meter I is: TCS stands for trichlorosilane.

5. The method for replenishing trichlorosilane in a distillation column as described in claim 1, characterized in that, In step S2, after generating the trichlorosilane supplementary flow rate, the generated trichlorosilane supplementary flow rate is smoothed and filtered using a filtering module.

6. The method for replenishing trichlorosilane in a distillation column as described in claim 1, characterized in that, Pump I, flow meter I, and flow regulating valve I are sequentially installed on the conveying pipeline between the feed tank and the distillation raw material tank. Flow meter I and flow regulating valve I provide flow indication and control. Pump I, flow meter I, and flow regulating valve I form a pump outlet flow control loop.

7. The method for replenishing trichlorosilane in a distillation column as described in claim 6, characterized in that, The pump outlet flow control circuit is connected to a pressure control circuit. The inlet of the pressure control circuit is connected to the pump outlet flow control circuit, and the outlet is connected to the feed tank. The pressure control circuit is equipped with a flow meter IV and a reflux regulating valve I. The pump outlet flow control circuit is equipped with a pressure sensor I. The pressure sensor I and the reflux regulating valve I are connected for pressure indication control.

8. The method for replenishing trichlorosilane in a distillation column as described in claim 7, characterized in that, In step S4, when conveying trichlorosilane, the reflux regulating valve I is opened to return excess material to the replenishment storage tank; The pressure sensor I detects the outlet pressure of pump I in real time. When the detected actual pressure is greater than the set pressure, the opening of the return flow regulating valve I is increased; when the pressure is less than the set pressure, the opening of the return flow regulating valve I is decreased.

9. The method for replenishing trichlorosilane in a distillation column as described in claim 1, characterized in that, In step S5, the material after distillation in the distillation column is transported to the downstream process via pump III. A material conveying pipeline and a material return pipeline are connected in parallel on the pipeline at the rear end of pump III. The outlet of the material return pipeline is connected to the feed storage tank. A flow meter VI and a flow regulating valve II are sequentially installed on the material conveying pipeline, and a flow meter V and a return regulating valve II are sequentially installed on the material return pipeline; a pressure sensor II is installed on the main pipeline at the rear end of pump III, and the pressure sensor II and the return regulating valve II are pressure indication and control.

10. The method for replenishing trichlorosilane in a distillation column as described in claim 9, characterized in that, In step S5, when conveying distillation material, the reflux regulating valve II is opened to return excess material to the feed storage tank; The pressure sensor II detects the outlet pressure of pump III in real time. When the detected actual pressure is greater than the set pressure, the opening of the return flow regulating valve II is increased; when the pressure is less than the set pressure, the opening of the return flow regulating valve II is decreased.

Images