Vacuum processing system for a polysilicon reduction furnace

Abstract

The utility model provides a kind of vacuum treatment system of polycrystalline silicon reduction furnace, and the purpose is to solve the technical problem of existing technology gas extraction speed bottleneck, the vacuum treatment system includes box, venturi, vacuum pump and buffer tank, and box interior is equipped with circulating liquid. One end of venturi is communicated with the inlet of box top, other end is communicated with the output end of vacuum pump, and the input end of vacuum pump is communicated with the outlet of box bottom. The outlet end of buffer tank is communicated with one end of venturi by a connecting pipe, and one end of connecting rod and venturi connection is close to vacuum pump. Circulating liquid in box is extracted by vacuum pump, and circulating liquid is transported to venturi, circulating liquid is accelerated in the middle of venturi, so that the inside of venturi is in negative pressure state, and then strong suction is generated to mixed gas in buffer tank, so that mixed gas and circulating liquid are mixed, and then dissolved in circulating liquid.

Description

Technical Field

[0001] This utility model relates to the field of mixed gas treatment technology in reduction furnaces, and specifically to a vacuum treatment system for a polycrystalline silicon reduction furnace. Background Technology

[0002] In the silane process for producing polysilicon, the start-up and shutdown of the reduction furnace are critical operational steps. To ensure operational safety, it is essential to thoroughly vacuum-purify and treat the residual chlorosilanes and other easily hydrolyzed and corrosive process gases within the furnace during this process. Currently, jet vacuum pumps (also known as water jet pumps) are commonly used as the core extraction equipment for this vacuum treatment step.

[0003] Its working principle is as follows: a driving circulating water pump generates a high-pressure water flow, which is accelerated by the nozzle of a jet pump to form a high-speed jet. Based on the Bernoulli effect, this jet generates a significant vacuum negative pressure in its throat region, thereby drawing in and mixing the process gas from the reduction furnace. Subsequently, the gas-liquid two-phase flow enters the diffusion section, where kinetic energy is converted into pressure energy, and finally, both are discharged into the absorption water tank at the rear. In this process, the circulating water not only serves as the working medium but also plays a role in the preliminary absorption and washing of the chlorosilane gas.

[0004] However, this existing technology based on the jet principle has revealed significant limitations in actual operation. The core problem lies in the slow extraction speed of residual mixed gas inside the furnace, resulting in low overall vacuum efficiency. This is mainly due to the structure and operating characteristics of the jet pump: on the one hand, it generates limited negative pressure and insufficient driving force, making it difficult to effectively overcome the flow resistance of the furnace body and piping system and quickly establish a high vacuum; on the other hand, the randomness and turbulence of the gas-liquid mixing process are insufficient, which may lead to low mass transfer efficiency and limit the gas processing capacity per unit time. Utility Model Content

[0005] To address the technical problem of the bottleneck in pumping speed in existing technologies, this invention provides a vacuum processing system for a polycrystalline silicon reduction furnace. By installing a Venturi tube between the vacuum pump and the chamber, the circulating liquid is accelerated within the Venturi tube, thereby increasing the negative pressure and improving the pumping speed.

[0006] The technical solution of this utility model is:

[0007] A vacuum processing system for a polycrystalline silicon reduction furnace includes:

[0008] The tank has an outlet at the bottom and an inlet at the top, and contains circulating fluid inside.

[0009] A venturi tube, one end of which is connected to the inlet of the box;

[0010] A vacuum pump, the output end of which is connected to the other end of the venturi tube, and the input end of which is connected to the bottom of the housing, is used to drive the flow of circulating fluid.

[0011] A buffer tank is used to buffer the mixed gas from the monocrystalline silicon reduction furnace. The buffer tank is connected to the end of the venturi tube near the vacuum pump via a connecting pipe.

[0012] Optionally, two vacuum pumps are provided between the buffer tank and the housing, and a venturi tube is provided between each of the two vacuum pumps and the housing.

[0013] Optionally, it also includes:

[0014] A spraying mechanism is located at the top of the tank and is used to spray the circulating liquid inside the tank.

[0015] Optionally, the spraying mechanism includes:

[0016] A conduit, one end of which is connected to the output end of the vacuum pump, and the other end of which is located at the top of the housing;

[0017] The nozzle is located at one end of the conduit at the top of the housing.

[0018] Optionally, it also includes:

[0019] The tank has one end located at the top of the box and the other end extending vertically upwards, forming a closed structure.

[0020] The spraying mechanism is located at the top of the tank.

[0021] Optionally, the end of the conduit extends from the side of the tank, and the nozzle is located at the top of the tank.

[0022] Optionally, the horizontal height at the connection between the tank and the box is higher than the horizontal height at the end of the venturi tube that connects to the box.

[0023] Optionally, an observation window is provided on the side of the enclosure.

[0024] Optionally, the end of the connecting pipe is located at the top of the buffer tank, and the bottom of the buffer tank is connected to the port for discharging the mixed gas from the monocrystalline silicon reduction furnace.

[0025] Compared with the prior art, the beneficial effects of this utility model are:

[0026] By installing a Venturi tube between the vacuum pump and the housing, the circulating fluid is accelerated within the Venturi tube, thereby increasing the negative pressure and improving the pumping speed. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a front view structural diagram of the present utility model;

[0029] Figure 2 This is a top view of the structure of this utility model. Detailed Implementation

[0030] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0031] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0032] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0033] Example:

[0034] See Figure 1 and Figure 2 This embodiment discloses a vacuum processing system for a polycrystalline silicon reduction furnace, including a housing 10, a venturi tube 20, a vacuum pump 30, and a buffer tank 40. The housing 10 has an inlet at the top and an outlet at the bottom, and is filled with circulating liquid.

[0035] One end of the venturi tube 20 is connected to the inlet at the top of the housing 10, and the other end is connected to the output end of the vacuum pump 30. The input end of the vacuum pump 30 is connected to the outlet at the bottom of the housing 10.

[0036] The inlet end of the buffer tank 40 is connected to the mixed gas outlet of the single crystal silicon reduction furnace, and the outlet end of the buffer tank 40 is connected to one end of the venturi tube 20 through a connecting pipe, and the end of the connecting rod connected to the venturi tube 20 is close to the vacuum pump 30.

[0037] In this embodiment, the mixed gas in the single-crystal silicon reduction furnace is output through its outlet and enters the buffer tank 40 through the connecting pipe, where it is temporarily stored. During the operation of this processing system, the circulating liquid in the tank 10 is extracted by the vacuum pump 30 and transported to the venturi tube 20. Since the cross-sectional area of ​​the middle part of the venturi tube 20 is smaller than that of its two ends, the circulating liquid is accelerated in the middle of the venturi tube 20, creating a negative pressure inside the venturi tube 20. This generates a strong suction force on the mixed gas in the buffer tank 40, thereby achieving mixing of the mixed gas and the circulating liquid, and then dissolving in the circulating liquid.

[0038] Preferably, in order to improve the processing speed of the mixed gas in the buffer tank 40, two vacuum pumps 30 are provided between the buffer tank 40 and the housing 10, and a venturi tube 20 is provided between the two vacuum pumps 30 and the housing 10, and the ends of the two venturi tubes 20 near the vacuum pumps 30 are connected to the buffer tank 40.

[0039] In another specific embodiment:

[0040] The vacuum treatment system also includes a spray mechanism 50, which is located on the top of the housing 10 and is capable of spraying circulating liquid into the housing 10.

[0041] Because the contact time between the gas mixture and the circulating liquid in the venturi tube 20 is limited, some of the gas mixture will enter the housing 10 and accumulate at the top of the housing 10. If the gas mixture encounters static electricity or an open flame, it is easy to cause a fire or explosion, and there is a risk of overflow. If the overflowing gas mixture enters the surrounding environment, it will cause environmental pollution and pose a risk of poisoning to passersby.

[0042] Therefore, a spraying mechanism 50 is provided at the top of the housing 10 so that the circulating liquid can be sprayed down from the top of the housing 10 and come into contact with the mixed gas gathered at the top of the housing 10 to fully dissolve the mixed gas.

[0043] Specifically, the spray mechanism 50 includes a conduit 51 and a nozzle 52, wherein one end of the conduit 51 is connected to the output end of the vacuum pump 30. Generally, a three-way pipe is installed on the output end of the vacuum pump 30, one port of which is connected to the end of the conduit 51. The other end of the conduit 51 passes into the housing 10 and is placed in the middle of the housing 10 before being connected to the nozzle 52, which faces downward.

[0044] In this embodiment, in order to avoid removing too much circulating fluid by installing a conduit 51 on the vacuum pump 30, it is necessary to control the flow rate of the circulating fluid in the conduit 51 to be less than the flow rate of the circulating fluid entering the venturi.

[0045] In another specific embodiment:

[0046] The vacuum processing system also includes a tank 60, one end of which is located at the top of the housing 10, and the other end of the tank 60 extends vertically upward and is a closed structure.

[0047] The aforementioned spraying mechanism 50 is located on the top of the inner side of the tank 60. Specifically, one end of the conduit 51 enters the interior of the tank 60 from the side and supports the nozzle 52 on the top of the tank 60.

[0048] In this embodiment, by setting a tank 60 on the top of the box 10, the mixed gas that is not fully dissolved in the venturi tube 20 can be gathered in the tank 60. Since the cross-sectional size of the tank 60 is relatively smaller than that of the box 10, the nozzle 52 can fully cover the internal space of the tank 60. Moreover, the tank 60 is a relatively long structure, which increases the contact time between the circulating liquid sprayed by the nozzle 52 and the mixed gas, so as to achieve the purpose of full dissolution.

[0049] In another specific embodiment:

[0050] The horizontal level at the connection between the tank 60 and the housing 10 is higher than the horizontal level at the end of the venturi tube 20 that connects to the housing 10. This design prevents the circulating fluid output from the end of the venturi tube 20 from entering the bottom of the tank 60.

[0051] In another specific embodiment:

[0052] An observation window 11 is provided on the side of the tank 10 for observing the liquid level inside the tank 10.

[0053] In another specific embodiment:

[0054] The end of the connecting pipe is located at the top of the buffer tank 40, and the bottom of the buffer tank 40 is connected to the port for discharging the mixed gas from the single crystal silicon reduction furnace. The buffer tank 40 mainly contains mixed gas. Through this design, the mixed gas in the buffer tank 40 can be fully discharged.

[0055] The embodiments described above merely illustrate specific implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A vacuum processing system for a polycrystalline silicon reduction furnace, characterized in that, include: The tank has an outlet at the bottom and an inlet at the top, and contains circulating fluid inside. A venturi tube, one end of which is connected to the inlet of the box; A vacuum pump, the output end of which is connected to the other end of the venturi tube, and the input end of which is connected to the bottom of the housing, is used to drive the flow of circulating fluid. A buffer tank is used to buffer the mixed gas from the monocrystalline silicon reduction furnace. The buffer tank is connected to the end of the venturi tube near the vacuum pump via a connecting pipe.

2. The vacuum processing system for the polycrystalline silicon reduction furnace according to claim 1, characterized in that, Two vacuum pumps are provided between the buffer tank and the housing, and a venturi tube is provided between each of the two vacuum pumps and the housing.

3. The vacuum processing system for the polycrystalline silicon reduction furnace according to claim 1, characterized in that, Also includes: A spraying mechanism is located at the top of the tank and is used to spray the circulating liquid inside the tank.

4. The vacuum processing system of the polycrystalline silicon reduction furnace according to claim 3, characterized in that, The spraying mechanism includes: A conduit, one end of which is connected to the output end of the vacuum pump, and the other end of which is located at the top of the housing; The nozzle is located at one end of the conduit at the top of the housing.

5. The vacuum processing system of the polycrystalline silicon reduction furnace according to claim 4, characterized in that, Also includes: The tank has one end located at the top of the box and the other end extending vertically upwards, forming a closed structure. The spraying mechanism is located at the top of the tank.

6. The vacuum processing system for the polycrystalline silicon reduction furnace according to claim 5, characterized in that, The end of the conduit enters from the side of the tank, and the nozzle is located at the top of the tank.

7. The vacuum processing system for the polycrystalline silicon reduction furnace according to claim 5, characterized in that, The horizontal height at the connection between the tank and the box is higher than the horizontal height at the end of the venturi tube that connects to the box.

8. The vacuum processing system for the polycrystalline silicon reduction furnace according to any one of claims 1-7, characterized in that, The side of the enclosure is equipped with an observation window.

9. The vacuum processing system for the polycrystalline silicon reduction furnace according to any one of claims 1-7, characterized in that, The end of the connecting pipe is located at the top of the buffer tank, and the bottom of the buffer tank is connected to the port for discharging mixed gas from the single crystal silicon reduction furnace.

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