Polycrystal reduction starting device and microwave power supply heating system

Abstract

The utility model discloses a polycrystalline reduction starting device and a microwave power supply heating system, and relates to the technical field of polycrystalline silicon, a polycrystalline reduction furnace comprises a reduction furnace base and a bell jar which are detachably connected, the polycrystalline reduction starting device is characterized in that the tail of a microwave energy feedback device is connected with a microwave transmission device, and the microwave transmission device is used for being connected with a microwave emission device; the microwave energy feedback device is installed on the surface of the bell jar and guides microwave energy into the polycrystalline reduction furnace to heat the silicon core. The microwave energy feedback device introduces microwave energy into the reduction furnace to heat the silicon core, so that the resistance value of the silicon core can be reduced, the silicon core can be subsequently subjected to breakdown start with lower voltage, microwave heating can be started at low voltage, the phenomenon of discharge sparking in the reduction furnace is avoided, an insulating part at the bottom of the reduction furnace is prevented from being damaged, and safe operation of equipment can be ensured; and other materials or impurities cannot enter the reduction furnace through microwave heating, so that the environment of the reduction furnace is prevented from being polluted, and the purity of generated polycrystalline silicon is prevented from being reduced.

Description

Technical Field

[0001] The present application relates to the technical field of polysilicon, and in particular to a polycrystalline reduction start-up device and a microwave power supply heating system. Background Art

[0002] There are two main ways to start polycrystalline reduction in the prior art: one is to use high voltage electricity to break down the silicon core to start; the other is to use a resistor to heat the silicon core first, and then use a relatively low voltage to break down the silicon core to start. When using high voltage to start, the excessive voltage can easily cause discharge and sparking in the reduction furnace, and the excessive voltage will break down the insulating parts outside the bottom electrode of the silicon core, affecting the safe operation of the equipment; when using resistor heating and low voltage to start, during the heating process, the materials of the electric radiation heater itself or the accompanying impurities will volatilize into the reduction furnace, affecting the purity of the generated polysilicon, and the polysilicon will adhere to the heater, affecting the service life of the heater and increasing the operating cost of the equipment.

[0003] Therefore, how to ensure the safe operation of the equipment and avoid affecting the purity of the generated polysilicon is a problem that needs to be solved by those skilled in the art. Utility Model Content

[0004] The purpose of this application is to provide a polycrystalline reduction starting device and a microwave power supply heating system to solve the following problems: excessively high voltage will break down the insulating parts on the outside of the bottom electrode of the silicon core, affecting the safe operation of the equipment; using resistance heating low-voltage starting, during the heating process, the materials of the electric radiation heater itself or the accompanying impurities will volatilize into the reduction furnace, affecting the purity of the generated polysilicon.

[0005] In order to solve the above-mentioned technical problems, the present application provides a polycrystalline reduction starting device, which is applied to a polycrystalline reduction furnace. The polycrystalline reduction furnace includes a detachably connected reduction furnace base and a bell jar. The polycrystalline reduction starting device includes: a microwave transmission device and at least one microwave energy feeding device. The tail of the microwave energy feeding device is connected to the microwave transmission device, and the microwave transmission device is used to connect a microwave transmitting device. The microwave energy feeding device is installed on the surface of the bell jar, and the microwave energy feeding device is used to introduce microwave energy into the interior of the polycrystalline reduction furnace to heat the silicon core.

[0006] Optionally, the bell jar includes an inner layer and a heat-insulating layer from the inside to the outside, and the head of the microwave energy feeding device is welded to the inner layer.

[0007] Optionally, the number of the microwave energy feeding device is one, and the one microwave energy feeding device is located in the middle of the silicon core in the height direction.

[0008] Optionally, there are multiple microwave energy feeding devices, and the multiple microwave energy feeding devices are arranged at intervals around the circumference of the bell jar.

[0009] Optionally, a plurality of the microwave energy feeding devices are arranged at intervals along the height direction of the bell jar.

[0010] Optionally, the plurality of microwave energy feeding devices are evenly distributed in the height direction of the silicon core.

[0011] Optionally, a plurality of pairs of silicon cores are arranged in a circle around the center of the reduction furnace base.

[0012] Optionally, a polysilicon reduction power supply is also included, and the polysilicon reduction power supply is connected to an electrode arranged on the reduction furnace base, and the polysilicon reduction power supply is used to provide voltage to the silicon core to perform breakdown start on the silicon core.

[0013] The present application also provides a microwave power supply heating system, comprising: the above-mentioned polycrystalline reduction starting device, a microwave power supply device and a microwave transmitting device;

[0014] The polycrystalline reduction starting device comprises a microwave transmission device and at least one microwave energy feeding device, wherein the microwave transmission device is respectively connected to the microwave energy feeding device and the microwave emitting device, and the microwave power supply device is connected to the microwave emitting device.

[0015] Optionally, the polycrystalline reduction furnace and the microwave energy feeding device are arranged in a reduction hall, and the microwave power supply device and the microwave transmitting device are arranged in a reduction power distribution hall.

[0016] A polycrystalline reduction start-up device provided in the present application is applied to a polycrystalline reduction furnace. The polycrystalline reduction furnace includes a detachably connected reduction furnace base and a bell cover. The polycrystalline reduction start-up device includes: a microwave transmission device and at least one microwave energy feeding device. The tail of the microwave energy feeding device is connected to the microwave transmission device. The microwave transmission device is used to connect the microwave transmitting device. The microwave energy feeding device is installed on the surface of the bell cover. The microwave energy feeding device is used to introduce microwave energy into the polycrystalline reduction furnace to heat the silicon core. The microwave energy feeding device is used to introduce microwave energy into the reduction furnace to heat the silicon core, which can reduce the resistance of the silicon core. Subsequently, the silicon core can be broken down and started by using a lower voltage. Microwave heating can be started at a low voltage, and there will be no discharge and sparking in the reduction furnace, which avoids damaging the insulating parts at the bottom of the reduction furnace, and can ensure the safe operation of the equipment; and microwave heating will not allow other materials or impurities to enter the reduction furnace, so as to avoid polluting the reduction furnace environment and reducing the purity of the generated polysilicon.

[0017] In addition, the microwave energy feeding device is installed on the surface of the bell jar instead of on the base of the reduction furnace. The main reason is that if the microwave energy feeding device is installed on the base of the reduction furnace, the dust in the bell jar will be deposited to the bottom of the bell jar, which will affect the microwave heating of the microwave energy feeding device.

[0018] The present application provides a microwave power heating system, which includes the above-mentioned polycrystalline reduction starting device, and has the above-mentioned effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic diagram of the installation of a first polycrystalline reduction startup device provided in an embodiment of the present application;

[0021] Figure 2 A top view of the installation of the first polycrystalline reduction startup device provided in an embodiment of the present application;

[0022] Figure 3 A schematic diagram of the installation of a second polycrystalline reduction startup device provided in an embodiment of the present application;

[0023] Figure 4 A top view of the installation of a second polycrystalline reduction startup device provided in an embodiment of the present application;

[0024] Figure 5 A distribution diagram of a first microwave power heating system provided in an embodiment of the present application;

[0025] Figure 6 A schematic diagram of the distribution of a second microwave power heating system provided in an embodiment of the present application;

[0026] The reference numerals are as follows: 1 is a reduction furnace base, 2 is a bell jar, 3 is a microwave energy feeding device, 4 is a microwave transmission device, 5 is a silicon core, 6 is a microwave transmitting device, and 7 is a microwave power supply device. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] The core of this application is to provide a polycrystalline reduction starting device and a microwave power supply heating system to ensure the safe operation of the equipment and avoid affecting the purity of the generated polycrystalline silicon.

[0029] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0030] Figure 1 This is a schematic diagram of the installation of the first polycrystalline reduction startup device provided in the embodiment of the present application. Figure 2 This is a top view of the installation of the first polycrystalline reduction startup device provided in the embodiment of the present application. Figure 3 This is a schematic diagram of the installation of the second polycrystalline reduction startup device provided in the embodiment of the present application. Figure 4 The installation top view of the second polycrystalline reduction startup device provided in the embodiment of the present application is as follows: Figures 1 to 4 As shown, the polycrystalline reduction furnace includes a detachably connected reduction furnace base 1 and a bell jar 2, and the polycrystalline reduction starting device includes: a microwave transmission device 4 and at least one microwave energy feeding device 3, the tail of the microwave energy feeding device 3 is connected to the microwave transmission device 4, the microwave transmission device 4 is used to connect the microwave emitting device 6, the microwave energy feeding device 3 is installed on the surface of the bell jar 2, and the microwave energy feeding device 3 is used to introduce microwave energy into the polycrystalline reduction furnace to heat the silicon core 5.

[0031] The embodiment of the present application does not limit the detachable connection method between the reduction furnace base 1 and the bell jar 2, which can be specifically connected by bolts. The microwave transmission device 4 in the embodiment of the present application can adopt a waveguide, which is connected to the tail of the microwave feeding device 3. The embodiment of the present application does not limit the number of microwave feeding devices 3 and how the microwave feeding devices 3 are installed on the surface of the bell jar 2; specifically, the bell jar 2 includes an inner layer and an insulation layer from the inside to the outside, and the head of the microwave feeding device 3 is welded to the inner layer. The microwave feeding device 3 is installed on the bell jar 2 by welding, which can improve the firmness. The larger the resistance, the weaker the conductivity, and the smaller the resistance, the stronger the conductivity; the microwave energy is introduced into the bell jar 2 by the microwave feeding device 3 to heat the silicon core 5. When the resistance of the silicon core 5 drops to a relatively low value, a lower voltage can be used to break down and start the silicon core 5. After microwave heating, it can be started at low voltage, and there will be no discharge and sparking in the reduction furnace, which will damage the insulating parts at the bottom of the reduction furnace and affect the safe operation of the equipment; microwave heating will not allow other materials or impurities to enter the reduction furnace, pollute the reduction furnace environment, and avoid reducing the purity of polysilicon. Based on this, a polysilicon reduction power supply can also be included, which is connected to the electrodes set on the reduction furnace base 1, and the polysilicon reduction power supply is used to provide voltage to the silicon core 5 to perform breakdown start on the silicon core 5.

[0032] A polycrystalline reduction start-up device provided in the embodiment of the present application is applied to a polycrystalline reduction furnace. The polycrystalline reduction furnace includes a detachably connected reduction furnace base and a bell cover. The polycrystalline reduction start-up device includes: a microwave transmission device and at least one microwave energy feeding device. The tail of the microwave energy feeding device is connected to the microwave transmission device. The microwave transmission device is used to connect the microwave transmitting device. The microwave energy feeding device is installed on the surface of the bell cover. The microwave energy feeding device is used to introduce microwave energy into the polycrystalline reduction furnace to heat the silicon core. The microwave energy feeding device is used to introduce microwave energy into the reduction furnace to heat the silicon core, which can reduce the resistance of the silicon core. Subsequently, the silicon core can be broken down and started by using a lower voltage. Microwave heating can be started at a low voltage, and there will be no discharge and sparking in the reduction furnace, which avoids damaging the insulating parts at the bottom of the reduction furnace, and can ensure the safe operation of the equipment; and microwave heating will not allow other materials or impurities to enter the reduction furnace, which avoids polluting the reduction furnace environment and reducing the purity of the generated polysilicon.

[0033] In addition, the microwave energy feeding device is installed on the surface of the bell jar instead of on the base of the reduction furnace. The main reason is that if the microwave energy feeding device is installed on the base of the reduction furnace, the dust in the bell jar will be deposited to the bottom of the bell jar, which will affect the microwave heating of the microwave energy feeding device.

[0034] Based on the above embodiments, Figure 1 and Figure 2 As shown, there is one microwave energy feeding device 3, and one microwave energy feeding device 3 is located in the middle of the height direction of the silicon core 5. If the number of silicon cores 5 inside the polycrystalline reduction furnace is small or the total weight of the silicon cores 5 is light, the reduction furnace is small, and the power required to heat the silicon cores 5 inside the reduction furnace is low, only one microwave energy feeding device 3 can be designed. At this time, the microwave energy feeding device 3 is installed on the surface of the bell jar and is located in the middle of the silicon core 5. When the microwave power supply is working, when the silicon core in the furnace is heated, the heat can be conducted up and down, shortening the heating time, saving power loss, improving power efficiency, and reducing the startup cost of polycrystalline reduction.

[0035] If there are a large number of silicon cores 5 in the polycrystalline reduction furnace or the total weight of the silicon cores 5 is heavy, the reduction furnace is large, and the power required to heat the silicon cores 5 in the reduction furnace is large, then multiple microwave energy feeding devices 3 need to be designed. Multiple microwave energy feeding devices 3 are arranged at intervals around the circumference of the bell jar 2. Further, multiple microwave energy feeding devices 3 are arranged at intervals along the height direction of the bell jar 2. Figure 3 As shown, the two microwave energy feeding devices 3 are located at different height directions of the bell jar 2, wherein the distance between one microwave energy feeding device 3 and the bottom of the reduction furnace is H1, and the distance between the other microwave energy feeding device 3 and the bottom of the reduction furnace is H2; Figure 4 As shown, the two microwave energy feeding devices 3 have a certain angle in the horizontal direction. Figure 4C in the figure represents the angle between the two microwave energy feeding devices 3. The multiple microwave energy feeding devices 3 are located at different heights and different directions. The microwave energy feeding devices 3 are designed to be aligned with different areas of the silicon core. When the microwave power supply is working and the silicon core in the furnace is heated, the heat can be conducted up and down, shortening the heating time, saving power loss, improving power efficiency, and reducing the startup cost of polycrystalline reduction.

[0036] If a plurality of microwave energy feeding devices 3 are installed on the surface of the bell jar 2, and the plurality of microwave energy feeding devices 3 are evenly spaced around the circumference of the bell jar 2, the plurality of microwave energy feeding devices 3 are evenly distributed in the height direction of the silicon core 5. The even distribution can evenly heat the silicon core 5, thereby ensuring that the growth conditions of each silicon core 5 are relatively consistent and improving the quality of the polysilicon product.

[0037] Based on the above embodiments, in the embodiment of the present application, multiple pairs of silicon cores 5 are arranged in a circle around the center of the reduction furnace base 1, such as Figure 2 and Figure 4 As shown, the silicon cores 5 form a plurality of concentric circles around the center of the reduction furnace base 1. Furthermore, the equal spacing between the silicon cores 5 and the uniform distribution facilitate full utilization of the space in the reduction furnace, so that the temperature of each silicon core 5 tends to be average, thereby ensuring that the growth of each silicon core 5 is relatively consistent and improving the quality of polysilicon products. The silicon core 5 is generally connected to the electrode through a graphite jacket and sealed, and the electrode is fixed to the reduction furnace base 1 and sealed, and a pair of silicon cores 5 are connected to each other at the top by silicon rods.

[0038] Figure 5 A schematic diagram of the distribution of the first microwave power heating system provided in the embodiment of the present application is shown in FIG. Figure 5 As shown, the microwave power heating system includes: the above-mentioned polycrystalline reduction starting device, microwave power supply device 7 and microwave transmitting device 6; the polycrystalline reduction starting device includes a microwave transmission device 4 and at least one microwave energy feeding device 3, the microwave transmission device 4 is respectively connected to the microwave energy feeding device 3 and the microwave transmitting device 6, and the microwave power supply device 7 is connected to the microwave transmitting device 6.

[0039] Furthermore, the polycrystalline reduction furnace and the microwave energy feeding device 3 are arranged in the reduction hall, and the microwave power supply device 7 and the microwave transmitting device 6 are arranged in the reduction power distribution hall. The reduction hall belongs to a high-cleanliness area. If the various devices in the microwave power heating system are installed in the reduction hall, it is easy to cause pollution to the hall when the personnel start the operation, which affects the quality of the silicon material; the power distribution equipment in the reduction hall has explosion-proof requirements. If the entire microwave power heating system is set here, then the microwave power supply device 7 and the microwave transmitting device 6 need to be explosion-proof, which is costly, occupies a large area, and may also cause safety hazards; when the microwave power supply device 7 and the microwave transmitting device 6 are working, low-temperature cooling water is required for heat dissipation. Generally, there is no low-temperature cooling water in the reduction hall, and a separate cooling water circuit needs to be designed, which increases the equipment investment cost. In the present application, the microwave power supply device 7 and the microwave transmitting device 6 are arranged in the reduction distribution hall on the first floor. The reduction distribution hall belongs to a common clean area. When personnel start the operation, it will not cause pollution to the reduction hall on the third floor, which can improve the quality of silicon materials and increase the competitiveness of silicon materials in the market; the microwave power supply device 7 and the microwave transmitting device 6 are arranged in the reduction distribution hall on the first floor. The distribution equipment in the reduction distribution hall has no explosion-proof requirements, so the microwave power supply device 7 and the microwave transmitting device 6 do not need to be designed to be explosion-proof, which reduces product costs, occupies a small area, and has no safety hazards; the microwave power supply device 7 and the microwave transmitting device 6 are arranged in the reduction distribution hall on the first floor. The reduction distribution hall has a low-temperature cooling water system, and there is no need to increase the investment in cooling water system equipment, thereby reducing costs.

[0040] The microwave power supply device 7 and the microwave transmitting device 6 are arranged in the reduction power distribution hall on the first floor, and the microwave is transmitted to the reduction furnace in the reduction hall on the third floor through the microwave transmission device 4 to heat the silicon core 5. The microwave power supply heating system can be one set to heat the reduction furnace, or multiple sets can be used to heat the reduction furnace at the same time, which is determined according to the power required to heat the silicon core 5. Figure 6 A schematic diagram of the distribution of a second microwave power heating system provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the reduction dry-type transformer room on the first floor is provided with a reduction transformer, the reduction power distribution hall on the first floor is provided with a reduction control cabinet and a reduction power cabinet, and the reduction power distribution hall can be provided with multiple microwave transmitting devices 6, such as Figure 6 As shown, two microwave transmitting devices 6 are respectively arranged beside the reduction control cabinet and the reduction power cabinet, and a microwave power supply device 7 is respectively arranged for the two microwave transmitting devices 6.

[0041] A microwave power supply heating system provided in an embodiment of the present application includes: the above-mentioned polycrystalline reduction starting device, microwave power supply device and microwave transmitting device; the polycrystalline reduction starting device includes: a microwave transmission device and at least one microwave energy feeding device, the tail of the microwave energy feeding device is connected to the microwave transmission device, the microwave transmission device is used to connect the microwave transmitting device, the microwave energy feeding device is installed on the surface of the bell jar, and the microwave energy feeding device is used to introduce microwave energy into the polycrystalline reduction furnace to heat the silicon core. The microwave energy feeding device is used to introduce microwave energy into the reduction furnace to heat the silicon core, which can reduce the resistance of the silicon core. Subsequently, the silicon core can be broken down and started by using a lower voltage. Microwave heating can be started at a low voltage, and there will be no discharge and sparking in the reduction furnace, which avoids damaging the insulating parts at the bottom of the reduction furnace, and can ensure the safe operation of the equipment; and microwave heating will not allow other materials or impurities to enter the reduction furnace, which avoids polluting the reduction furnace environment and reducing the purity of the generated polysilicon.

[0042] The above is a detailed introduction to a polycrystalline reduction start-up device and a microwave power supply heating system provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0043] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A polycrystalline reduction starting device, applied to a polycrystalline reduction furnace, the polycrystalline reduction furnace comprising a detachably connected reduction furnace base (1) and a bell jar (2), characterized in that: include: A microwave transmission device (4) and at least one microwave energy feeding device (3), wherein the tail of the microwave energy feeding device (3) is connected to the microwave transmission device (4), the microwave transmission device (4) is used to connect to a microwave emitting device (6), the microwave energy feeding device (3) is installed on the surface of the bell jar (2), and the microwave energy feeding device (3) is used to introduce microwave energy into the interior of the polycrystalline reduction furnace to heat the silicon core (5).

2. The polycrystalline reduction startup device according to claim 1, characterized in that: The bell jar (2) comprises an inner layer and a heat-insulating layer in sequence from the inside to the outside, and the head of the microwave energy feeding device (3) is welded to the inner layer.

3. The polycrystalline reduction starting device according to claim 2, characterized in that: The number of the microwave energy feeding device (3) is one, and the one microwave energy feeding device (3) is located in the middle of the silicon core (5) in the height direction.

4. The polycrystalline reduction starting device according to claim 2, characterized in that: The number of the microwave energy feeding devices (3) is plural, and the plural microwave energy feeding devices (3) are arranged at intervals around the circumference of the bell jar (2).

5. The polycrystalline reduction startup device according to claim 4, characterized in that: The plurality of microwave energy feeding devices (3) are arranged at intervals along the height direction of the bell jar (2).

6. The polycrystalline reduction startup device according to claim 5, characterized in that: The plurality of microwave energy feeding devices (3) are evenly distributed in the height direction of the silicon core (5).

7. The polycrystalline reduction startup device according to claim 1, characterized in that: A plurality of pairs of silicon cores (5) are arranged in a circle around the center of the reduction furnace base (1).

8. The polycrystalline reduction starting device according to any one of claims 1 to 7, characterized in that: It also comprises a polycrystalline silicon reduction power supply, the polycrystalline silicon reduction power supply is connected to an electrode arranged on the reduction furnace base (1), and the polycrystalline silicon reduction power supply is used to provide a voltage to the silicon core (5) so as to perform a breakdown start on the silicon core (5).

9. A microwave power heating system, characterized in that: include: The polycrystalline reduction starting device, microwave power supply device (7) and microwave emitting device (6) as claimed in any one of claims 1 to 8; The polycrystalline reduction starting device comprises a microwave transmission device (4) and at least one microwave energy feeding device (3), wherein the microwave transmission device (4) is respectively connected to the microwave energy feeding device (3) and the microwave emitting device (6), and the microwave power supply device (7) is connected to the microwave emitting device (6).

10. The microwave power heating system according to claim 9, characterized in that: The polycrystalline reduction furnace and the microwave energy feeding device (3) are arranged in a reduction hall, and the microwave power supply device (7) and the microwave transmitting device (6) are arranged in a reduction power distribution hall.

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