Thermocouple special for polycrystalline silicon smelting furnace

Abstract

The utility model discloses a special thermocouple for a polycrystalline silicon smelting furnace, which comprises a temperature measuring line and a protective tube, the temperature measuring line comprises at least one group of thermode core wires, each group of thermode core wires comprises a temperature measuring section positioned inside the protective tube and an external leading section extending to the outside of the protective tube, the end part of each temperature measuring section is provided with a temperature measuring end point, and the temperature measuring end point is provided with a temperature measuring groove. The end part of each outer leading section is connected with an external element; a clamping sleeve is sleeved at the joint of the temperature measuring section and the outer leading section, and is fixedly connected to the upper end of the protective tube; the protection tube comprises an anti-corrosion layer located on the outermost layer, and the anti-corrosion layer is a quartz tube. The protection tube is provided with the anti-corrosion layer made of the quartz material, so that the environment in the furnace cannot be polluted when the thermocouple is used for monitoring the temperature of the polycrystalline silicon smelting furnace, and the purity of polycrystalline silicon is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of thermocouples, and in particular relates to a thermocouple dedicated to a polysilicon melting furnace. Background Art

[0002] A polysilicon furnace is a device for preparing polysilicon, which heats silicon material to its melting point at high temperature to form liquid silicon, and then adds crystals to the liquid silicon. Under the action of the crystals, the liquid silicon gradually solidifies into polysilicon through a crystallization reaction. Therefore, during the polysilicon production process, it is necessary to monitor the temperature in the polysilicon furnace. Currently, thermocouples are mostly used to monitor the temperature in the polysilicon furnace. In order to prevent chemical corrosion and mechanical damage to the core part of the thermocouple, the thermocouple, a protective tube is often installed outside the thermocouple. However, the existing thermocouple protection tubes are mostly made of stainless steel. When the above-mentioned thermocouple monitors the temperature in the polysilicon furnace, under high temperature conditions, impurities in the stainless steel protection tube are easily precipitated, causing pollution to the polysilicon production environment, reducing the purity of polysilicon and affecting the quality of polysilicon. Summary of the invention

[0003] The utility model aims to solve the problem that when the thermocouple in the prior art monitors the temperature of a polysilicon furnace, impurities will be precipitated from the stainless steel protection tube under high temperature environment, thus affecting the purity of polysilicon. The utility model provides a thermocouple specially used for polysilicon furnace.

[0004] The invention objective of the utility model is achieved through the following technical solutions:

[0005] A thermocouple specially used in a polysilicon melting furnace comprises a temperature measuring wire and a protection tube. The temperature measuring wire comprises at least one group of thermoelectrode core wires. Each group of thermoelectrode core wires comprises a temperature measuring section located inside the protection tube and an external lead section extending to the outside of the protection tube. The end of each temperature measuring section has a temperature measuring end point, and the end of each external lead section is connected to an external element. A ferrule is provided at the connection position between the temperature measuring section and the external lead section, and the ferrule is fixedly connected to the upper end of the protection tube. The protection tube comprises an anti-corrosion layer located at the outermost layer, and the anti-corrosion layer is a quartz tube.

[0006] Preferably, the protection tube is a multi-layer structure, which also includes a reinforcement layer located inside the anti-corrosion layer.

[0007] Preferably, the reinforcement layer is a quartz tube or a stainless steel tube.

[0008] Preferably, the temperature measuring wire comprises three groups of thermode core wires, namely a first core wire, a second core wire and a third core wire, and the three groups of core wires are insulated and separated.

[0009] Preferably, the first core wire includes a first temperature measuring section and a first outer lead section, the second core wire includes a second temperature measuring section and a second outer lead section, and the third core wire includes a third temperature measuring section and a third outer lead section; the end of the first temperature measuring section has a first temperature measuring endpoint, the end of the second temperature measuring section has a second temperature measuring endpoint, and the end of the third temperature measuring section has a third temperature measuring endpoint; the first temperature measuring endpoint, the second temperature measuring endpoint and the third temperature measuring endpoint are staggered in the length direction of the temperature measuring line.

[0010] Preferably, the external connection element is a quick-connect plug, the end of the first external lead section is connected to a first quick-connect plug, the end of the second external lead section is connected to a second quick-connect plug, and the end of the third external lead section is connected to a third quick-connect plug.

[0011] Preferably, the first core wire, the second core wire and the third core wire are all composed of two alloy wires and an insulating sleeve, and the two plug-in pieces of the first quick-connect plug, the second quick-connect plug and the third quick-connect plug are respectively made of the same material as the two alloy wires.

[0012] Compared with the prior art, the utility model has the following technical effects: in this solution, the protective tube is provided with an anti-corrosion layer of quartz material, and the thermocouple will not pollute the furnace environment when monitoring the temperature of the polysilicon furnace, thereby ensuring the purity of the polysilicon; the temperature measuring line includes three groups of thermoelectrode core wires, and the temperature measuring end points of each group of core wires are staggered, which can realize multi-point temperature measurement and better monitor the temperature in the furnace; the external component adopts a quick-connect plug, and the external connection is faster and more convenient; the two plugs of the external plug are respectively consistent with the two alloy wire materials of the core wire, which can effectively improve the sensitivity of the thermocouple. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the utility model;

[0014] Figure 2 This is a schematic diagram of the temperature measuring section structure of the hot electrode core wire in the utility model;

[0015] Figure 3 This is a schematic diagram of the structure of the external lead section of the hot electrode core wire in the utility model;

[0016] Markings in the figure: quartz tube 10; first temperature measuring section 21; first temperature measuring endpoint 211; first external section 22; first quick-connect plug 23; second temperature measuring section 31; second temperature measuring endpoint 311; second external section 32; second quick-connect plug 33; third temperature measuring section 41; third temperature measuring endpoint 411; third external section 42; third quick-connect plug 43; ferrule 50. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings:

[0018] See also Figure 1-Figure 3 This embodiment discloses a thermocouple dedicated to a polysilicon furnace, which is used to monitor the temperature of the polysilicon furnace, and includes a temperature measuring wire and a protection tube.

[0019] The temperature measuring wire includes three groups of thermoelectrode core wires, each group of thermoelectrode core wires includes a temperature measuring section located inside the protection tube, and an external lead section extending to the outside of the protection tube, each of the temperature measuring sections has a temperature measuring end point at the end, and each of the external lead sections is connected to an external element at the end; a sleeve 50 is provided at the connection position between the temperature measuring section and the external lead section, and the sleeve 50 is fixedly connected to the upper end of the protection tube.

[0020] The three groups of thermocouple core wires are respectively the first core wire, the second core wire and the third core wire, and the three groups of core wires are insulated and separated; the first core wire includes a first temperature measuring section 21 and a first external lead section 22, the second core wire includes a second temperature measuring section 31 and a second external lead section 32, and the third core wire includes a third temperature measuring section 41 and a third external lead section 42; the end of the first temperature measuring section 21 has a first temperature measuring endpoint 211, the end of the second temperature measuring section 31 has a second temperature measuring endpoint 311, and the end of the third temperature measuring section 41 has a third temperature measuring endpoint 411; the first temperature measuring endpoint 211, the second temperature measuring endpoint 311 and the third temperature measuring endpoint 411 are staggered in the length direction of the temperature measuring line, and the temperature measuring endpoints of each group of core wires are staggered, which can realize multi-point temperature measurement and better monitor the temperature in the furnace.

[0021] The protection tube includes an anti-corrosion layer located at the outermost layer, and the anti-corrosion layer is a quartz tube 10. When the thermocouple monitors the temperature of the polysilicon furnace, it will not cause pollution to the furnace environment, thereby ensuring the purity of the polysilicon. In practical applications, in order to improve the structural strength of the protection tube, the protection tube can adopt a multi-layer structure, and a reinforcement layer is added inside the quartz tube 10. The reinforcement layer can be a quartz tube 10 or a stainless steel tube.

[0022] The external connection element is a quick-connect plug, which makes external connection faster and more convenient. The end of the first external lead section 22 is connected to the first quick-connect plug 23, the end of the second external lead section 32 is connected to the second quick-connect plug 33, and the end of the third external lead section 42 is connected to the third quick-connect plug 43.

[0023] The first core wire, the second core wire and the third core wire are all composed of two alloy wires and an insulating sleeve. In this embodiment, the thermocouple is an N-type thermocouple, and the two alloy wires are nickel-chromium-silicon alloy wire and nickel-silicon alloy wire. In order to improve the sensitivity of the thermocouple, the two plug-in pieces of the first quick-connect plug 23, the second quick-connect plug 33 and the third quick-connect plug 43 are respectively consistent with the materials of the two alloy wires.

[0024] It should be understood that in the claims and description of the utility model, all "including..." should be understood as open-ended meanings, that is, their meanings are equivalent to "at least including...", and should not be understood as closed-ended meanings, that is, their meanings should not be understood as "only including...". The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0025] The above is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should be covered by the protection scope of the utility model.

Claims

1. A thermocouple for a polysilicon melting furnace, comprising a temperature measuring wire and a protective tube, It is characterized in that The temperature measuring wire includes at least one group of thermoelectrode core wires, each group of thermoelectrode core wires includes a temperature measuring section located inside a protective tube, and an external lead section extending to the outside of the protective tube, each end of the temperature measuring section has a temperature measuring end point, and each end of the external lead section is connected to an external element; a ferrule is provided at the connection position between the temperature measuring section and the external lead section, and the ferrule is fixedly connected to the upper end of the protective tube; the protective tube includes an anti-corrosion layer located at the outermost layer, and the anti-corrosion layer is a quartz tube.

2. A thermocouple for a polysilicon melting furnace according to claim 1, It is characterized in that The protection tube is a multi-layer structure, which also includes a reinforcement layer located inside the anti-corrosion layer.

3. A thermocouple for a polysilicon melting furnace according to claim 2, It is characterized in that The reinforcement layer is a quartz tube or a stainless steel tube.

4. A thermocouple for a polysilicon melting furnace according to any one of claims 1 to 3, It is characterized in that The temperature measuring wire comprises three groups of thermode core wires, namely a first core wire, a second core wire and a third core wire, and the three groups of core wires are insulated and separated.

5. A thermocouple for a polysilicon melting furnace according to claim 4, It is characterized in that The first core wire includes a first temperature measuring section and a first outer lead section, the second core wire includes a second temperature measuring section and a second outer lead section, and the third core wire includes a third temperature measuring section and a third outer lead section; the end of the first temperature measuring section has a first temperature measuring endpoint, the end of the second temperature measuring section has a second temperature measuring endpoint, and the end of the third temperature measuring section has a third temperature measuring endpoint; the first temperature measuring endpoint, the second temperature measuring endpoint and the third temperature measuring endpoint are staggered in the length direction of the temperature measuring line.

6. A thermocouple for a polysilicon melting furnace according to claim 5, It is characterized in that The external connection element is a quick-connect plug. The end of the first external lead section is connected to a first quick-connect plug. The end of the second external lead section is connected to a second quick-connect plug. The end of the third external lead section is connected to a third quick-connect plug.

7. A thermocouple for a polysilicon melting furnace according to claim 6, It is characterized in that The first core wire, the second core wire and the third core wire are all composed of two alloy wires and an insulating sleeve, and the two plug-in pieces of the first quick-connect plug, the second quick-connect plug and the third quick-connect plug are respectively made of the same material as the two alloy wires.

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