Quartz crucible melting equipment
By employing a three-part conical discharge tower structure in the quartz crucible melting equipment, and utilizing multi-layer heating zones and adjustable electrode rod distance and angle, the problems of slow and uneven heating speed were solved, achieving a faster and more uniform heating effect and improving preparation efficiency.
Patent Information
- Application Number
- CN202511040241.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-28
- Publication Date
- 2025-11-11
AI Technical Summary
Existing quartz crucible melting equipment has a slow and uneven heating rate during the heating process, and cannot perform multi-point heating according to the size of the crucible, resulting in low preparation efficiency.
A three-section conical discharge tower structure is adopted. By setting three sets of positive graphite electrode rods and three rings of negative graphite electrode rods, a multi-layer heating zone is formed. The distance and angle of the electrode rods are adjusted by using a lifting frame and a negative electrode displacement component to achieve uniform heating.
It heats up faster, distributes heat more evenly, and can adapt to the needs of preparing crucibles of different sizes, thus improving preparation efficiency.
Smart Images
Figure CN120923134A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of crucible melting technology, and in particular relates to a quartz crucible melting device. Background Technology
[0002] In the processing of new energy silicon crystals, high-purity quartz crucibles are required to hold molten silicon. The production process of high-purity quartz crucibles includes: first, quartz sand is evenly placed in a rotating mold; then, an AC electrode arc discharge is used to heat and melt the quartz sand; next, the mold is rotated to form a crucible model; finally, the quartz crucible is formed, demolded, and cooled to form the finished quartz crucible.
[0003] The stability of the electric arc is ensured by adjusting parameters such as voltage, current, and arc length. When the voltage reaches a certain value, as current flows through the air between the two electrodes, electrons leave one electrode and move at high speed to the other. During this process, electrons collide with and move through gas molecules, ionizing the molecules in the gas and forming positively charged ions and negatively charged free electrons. This mixture of charged particles is called high-temperature plasma. The energy released by the collisions of plasma in the electric field leads to luminescence and heat generation, exciting the air molecules around the gas and causing the excited-state molecules to radiate, forming light in the visible spectrum. Therefore, plasma has a high temperature.
[0004] However, existing electric arc generation typically concentrates at a single point, resulting in slow heating. Furthermore, the heating speed varies depending on the crucible size and the type of crucible used. This is because the discharge point is essentially a single area. It is impossible to achieve balanced heating by applying heating to multiple points within the mold based on the crucible size.
[0005] To address these issues, we provide a quartz crucible melting apparatus. Summary of the Invention
[0006] The purpose of this invention is to provide a quartz crucible melting device that forms a three-layered conical discharge tower by setting up three layers of positive graphite electrode rods and three rings of negative graphite electrode rods, which can form a larger heating area and solve the problems of existing heating methods, such as heating at one point, slow heating speed, and uneven heating.
[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention relates to a quartz crucible melting device, comprising a lifting frame, a mounting plate, a positive electrode mounting assembly, and a negative electrode displacement assembly. The positive electrode mounting assembly is mounted below the mounting plate via a connecting rod assembly. The positive electrode mounting assembly includes a positive electrode ceramic sleeve with three sets of positive electrode graphite rods. The mounting plate has three evenly spaced rings of negative electrode displacement assemblies. The negative electrode graphite rods mounted on each ring of the negative electrode displacement assemblies will correspondingly connect with each set of positive electrode graphite rods for discharge. The bottom ends of the negative electrode graphite rods on the outermost ring of the negative electrode displacement assemblies are positioned around the bottom ends of one positive electrode graphite rod in the central group. The bottom ends of the negative electrode graphite rods on the middle ring of the negative electrode displacement assemblies are positioned around the bottom ends of multiple positive electrode graphite rods in the middle group. The bottom ends of the negative electrode graphite rods on the innermost ring of the negative electrode displacement assemblies are positioned around the bottom ends of multiple positive electrode graphite rods in the outermost group. The bottom ends of the negative electrode graphite rods surrounding the bottom ends of the positive electrode graphite rods form a conical discharge tower.
[0008] The present invention is further configured such that the mounting plate includes a disk, a plurality of mounting strips evenly distributed around the circumference of the disk, and an upward-facing cylinder at the center of the disk. Each mounting strip has a first mounting square hole and a second mounting square hole from the outermost end inward. The disk has a third mounting square hole between adjacent mounting strips. A first negative graphite electrode rod is mounted on the negative electrode displacement component in the first mounting square hole, a second negative graphite electrode rod is mounted on the negative electrode displacement component in the second mounting square hole, and a third negative graphite electrode rod is mounted on the negative electrode displacement component in the third mounting square hole. The positive electrode ceramic sleeve includes a core post, a first winding post, and a second winding post. The upper half of the outer wall of the core post is evenly surrounded by multiple first winding posts. The upper half of each adjacent first winding post is fixed with an outward-facing second winding post. A first positive electrode graphite electrode rod, a second positive electrode graphite electrode rod, and a third positive electrode graphite electrode rod are respectively passed through the core post, the first winding post, and the second winding post.
[0009] The present invention is further configured such that the discharge ends of the first positive graphite electrode rod, the second positive graphite electrode rod, and the third positive graphite electrode rod are exposed at the bottom of the core post, the bottom of the first winding post, and the bottom of the second winding post. The first negative electrode graphite electrode rod, the second negative electrode graphite electrode rod 32, and the third negative electrode graphite electrode rod are all coated with an insulating ceramic layer at the discharge end at the bottom. The discharge ends at the bottom of all positive graphite electrodes and all negative graphite electrode rods are tapered discharge ends.
[0010] The present invention is further configured such that there is only one first positive graphite electrode rod, the second and third positive graphite electrode rods have the same diameter and number and are all no less than four, and the diameter of the first positive graphite electrode rod is more than twice the diameter of the second positive graphite electrode rod. The first negative graphite electrode rod, the second negative graphite electrode rod, and the third negative graphite electrode rod have the same diameter and number, and their diameter and number are also the same as those of the second positive graphite electrode rod.
[0011] The present invention is further configured such that the distance between the bottom ends of the first positive graphite electrode rod and the second positive graphite electrode rod, and the distance between the bottom ends of the second positive graphite electrode rod and the third positive graphite electrode rod, are both not less than 10 cm, and the distance between the bottom ends of the first positive graphite electrode rod and the third positive graphite electrode rod is not less than half the height of the inner cavity of the quartz crucible.
[0012] The invention is further configured such that the negative electrode displacement assembly includes a displacement box, an angle adjustment block, and a graphite electrode sleeve. The top two sides of the displacement box are mounting plates. A displacement cylinder assembly is located on the rear side of the displacement box near the top. The displacement box has a vertically penetrating adjustment square hole. A rotating platform is located on the inner rear wall of the adjustment square hole near the top. A cylinder frame is installed on the rear wall of the displacement box near the bottom. A rotating beam is located on the rear wall of the angle adjustment block near the top. The rotating beam is rotatably mounted on the two side walls of the rotating platform via a shaft. A cylinder connector is located in the middle of the rear wall of the angle adjustment block near the bottom. An angle adjustment cylinder is connected between the cylinder frame and the cylinder connector. The angle adjustment block is inserted into the adjustment square hole. A connecting rod insertion hole is provided on the angle adjustment block. A bent connecting rod is inserted into the connecting rod insertion hole, and a graphite electrode sleeve is fixed to the bottom end of the bent connecting rod.
[0013] The present invention is further configured such that the displacement box moves within the first mounting square hole, the second mounting square hole, and the third mounting square hole by a distance of 8-12 mm, and the angle adjustment block adjusts to a maximum angle of 5°.
[0014] The present invention is further configured such that the lifting frame includes a square sleeve, a square lifting column and a lifting motor, the lifting motor is embedded in the top of the square sleeve, a lead screw is connected to the shaft of the lifting motor, the square lifting column is movably inserted into the square sleeve from the bottom, and the lead screw is spirally inserted downward from the center of the top of the square lifting column.
[0015] The present invention is further configured such that the voltage difference between each group of positive graphite electrode rods and the corresponding ring of negative graphite electrode rods is the same or increases progressively from top to bottom.
[0016] The present invention has the following beneficial effects: 1. This invention features three layers of positive graphite electrode rods (with only one rod at the bottom). Three rings of negative graphite electrode rods are matched and inserted into a crucible mold to discharge and heat the raw material. Since there are three discharge layers, the bottom layer is concentrated at the bottom of the first positive graphite electrode rod, and the second and third layers are the rings surrounded by the second and third positive graphite electrode rods, respectively. The heating arc forms a conical discharge tower, resulting in a wider heating range, faster melting, and better control of the heating speed.
[0017] 2. Each negative electrode displacement component of the present invention can finely adjust the negative electrode graphite electrode rod and angle to adjust the distance and angle between the bottom ends of the negative electrode graphite electrode rod and the positive electrode graphite electrode rod, so as to adapt to the change in arc intensity under voltage changes, thereby controlling the heating efficiency.
[0018] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description
[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of a quartz crucible melting device.
[0021] Figure 2 This is a schematic diagram of the exploded structure of a quartz crucible melting device.
[0022] Figure 3 This is a schematic diagram of the exploded structure of the negative electrode displacement component.
[0023] Figure 4 This is a schematic diagram of the displacement box.
[0024] Figure 5 This is a schematic diagram of the angle adjustment block.
[0025] Figure 6 This is a structural diagram of the mounting plate.
[0026] Figure 7 This is a schematic diagram of the positive electrode ceramic sleeve.
[0027] The attached diagram lists the components represented by each number as follows: 1. Lifting frame; 11. Square sleeve; 12. Square lifting column; 13. Lifting motor; 131. Lead screw; 2. Mounting plate; 20. Cylindrical column; 21. Disc; 211. Third mounting square hole; 22. Mounting strip; 221. First mounting square hole; 222. Second mounting square hole; 3. Negative electrode graphite rod; 31. First negative electrode graphite rod; 32. Second negative electrode graphite rod; 33. Third negative electrode graphite rod 4. Positive electrode mounting assembly; 41. Positive electrode ceramic sleeve; 411. Core post; 412. First winding post; 413. Second winding post; 414. Connecting rod assembly; 5. Negative electrode displacement assembly; 51. Displacement box; 511. Displacement cylinder; 512. Cylinder frame; 513. Adjustment square hole; 514. Rotary table; 52. Angle adjustment block; 53. Cylinder connector; 54. Bending connecting rod; 55. Graphite electrode sleeve. Detailed Implementation
[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0029] Please see Figure 1-7 This invention relates to a quartz crucible melting device, comprising a lifting frame 1, a mounting plate 2, a positive electrode mounting assembly 4, and a negative electrode displacement assembly 5. The positive electrode mounting assembly 4 is mounted below the mounting plate 2 via a connecting rod assembly 414. The positive electrode mounting assembly 4 includes a positive electrode ceramic sleeve 41, on which three sets of positive electrode graphite electrode rods 42 are mounted. The mounting plate 2 has three evenly distributed rings of negative electrode displacement assemblies 5, with each ring of negative electrode graphite electrode rods 3 corresponding to one set of positive electrode graphite electrode rods 42. Discharge is then carried out. The bottom ends of the negative graphite electrode rods 3 on the outermost ring of the negative electrode displacement component 5 are arranged around the bottom ends of one positive graphite electrode rod 42 in the central group. The bottom ends of the negative graphite electrode rods 3 on the middle ring of the negative electrode displacement component 5 are arranged around the bottom ends of multiple positive graphite electrode rods 42 in the middle group. The bottom ends of the negative graphite electrode rods 3 on the innermost ring of the negative electrode displacement component 5 are arranged around the bottom ends of multiple positive graphite electrode rods 42 in the outermost group. After the bottom ends of the negative graphite electrode rods 3 surround the bottom ends of the positive graphite electrode rods 42, a conical discharge tower will be formed.
[0030] The mounting plate 2 and the structure below it can be moved up and down using the lifting bracket 1. When moving down, the positive electrode ceramic sleeve 41, three sets of positive electrode graphite electrode rods 42, and three rings of negative electrode graphite electrode rods 3 are inserted into the crucible mold. Raw material powder is introduced into the crucible mold, and the power supply (DC power supply) is started to heat up, forming three discharge rings that gradually increase in size from bottom to top. However, the discharge rings at the bottom layer have a high degree of concentration, while those at the top are dispersed. In this way, the heating is no longer a single point (similar to heating the bottommost ring), but rather three layers or more are designed for heating, resulting in faster heating speed and more uniform heating.
[0031] The mounting plate 2 includes a disc 21, a plurality of mounting strips 22 evenly distributed around the circumference of the disc 21, and an upward-facing cylinder 20 at the center of the disc 21. Each mounting strip 22 has a first mounting square hole 221 and a second mounting square hole 222 respectively from the outermost end inward. The disc 21 has a third mounting square hole 211 between adjacent mounting strips 22. A first negative electrode graphite electrode rod 31 is installed on the negative electrode displacement component 5 in the first mounting square hole 221, a second negative electrode graphite electrode rod 32 is installed on the negative electrode displacement component 5 in the second mounting square hole 222, and a third negative electrode graphite electrode rod 33 is installed on the negative electrode displacement component 5 in the third mounting square hole 211. The design of the disc 21 structure can form multiple rings of mounting square holes to install the negative electrode displacement component 5. The negative electrode displacement component 5 is used to drive the negative electrode graphite electrode rod 3 to move closer to the positive electrode graphite electrode rod 42, and to finely adjust the included angle.
[0032] The positive electrode ceramic sleeve 41 includes a core post 411, a first winding post 412, and a second winding post 413. The upper half of the outer wall of the core post 411 is evenly surrounded by a plurality of first winding posts 412. A second winding post 413 is fixedly provided on the upper half of each adjacent first winding post 412. A first positive electrode graphite electrode rod, a second positive electrode graphite electrode rod, and a third positive electrode graphite electrode rod are respectively passed through the core post 411, the first winding post 412, and the second winding post 413.
[0033] The positive electrode ceramic sleeve 41 ensures insulation between the positive electrode graphite rods while also allowing them to be clustered together, facilitating control of the discharge arc density (the arc is on an inverted conical tower). Figure 2 and 7 As shown, after the positive electrode graphite electrode rod 42 is installed on the positive electrode ceramic sleeve 41, it is tightly exposed at the bottom discharge end, which can form an electric arc with the negative electrode graphite electrode rod.
[0034] The first positive graphite electrode rod, the second positive graphite electrode rod, and the third positive graphite electrode rod all have their bottom discharge ends exposed at the bottom ends of the core post 411, the first winding post 412, and the second winding post 413. The first negative electrode graphite electrode rod 31, the second negative electrode graphite electrode rod 32 and the third negative electrode graphite electrode rod 33 are all coated with an insulating ceramic layer at the discharge end at the bottom. The discharge ends at the bottom of all positive graphite electrodes 42 and all negative graphite electrode rods are tapered discharge ends.
[0035] Because the negative graphite electrode rod 31 has a high density of surrounding material, an insulating ceramic coating layer is provided to prevent leakage or abnormal electrical conduction due to contact, thus preventing power supply abnormalities caused by contact.
[0036] There is only one first positive graphite electrode rod. The second and third positive graphite electrode rods have the same diameter and number, and there are no fewer than four of them. The diameter of the first positive graphite electrode rod is more than twice the diameter of the second positive graphite electrode rod. The first negative graphite electrode rod 31, the second negative graphite electrode rod 32, and the third negative graphite electrode rod 33 have the same diameter and number, and their diameter and number are the same as those of the second positive graphite electrode rod.
[0037] The first positive graphite electrode rod is relatively thick because it needs to discharge in correspondence with multiple first negative graphite electrode rods 31. The second negative graphite electrode rod 32 and the third negative graphite electrode rod 33 discharge one-to-one with the second and third positive graphite electrode rods. This relatively thinner design allows for a more reasonable reduction in installation space and facilitates arrangement.
[0038] The distance between the bottom ends of the first positive graphite electrode rod and the second positive graphite electrode rod, and the distance between the bottom ends of the second positive graphite electrode rod and the third positive graphite electrode rod, are both not less than 10 cm. The distance between the bottom ends of the first positive graphite electrode rod and the third positive graphite electrode rod is not less than half the height of the inner cavity of the quartz crucible.
[0039] The first positive graphite electrode rod should almost touch the inside of the mold, the second positive graphite electrode rod should be positioned slightly below the center of the mold, and the third positive graphite electrode rod should be positioned slightly above the center. This design allows for better discharge heating and also accommodates the narrow bottom and wide top of the crucible.
[0040] The negative electrode displacement assembly 5 includes a displacement box 51, an angle adjustment block 52, and a graphite electrode sleeve 55. The top two sides of the displacement box 51 are supporting plates. A set of displacement cylinders 511 is located on the rear side of the displacement box 51 near the top. The displacement box 51 has a vertically penetrating adjustment square hole 513 inside. A rotating platform 514 is located on the inner rear wall of the adjustment square hole 513 near the top. A cylinder bracket 512 is installed on the rear wall of the displacement box 51 near the bottom. A rotating platform 514 is located on the rear wall of the angle adjustment block 52 near the top. The rotating beam 521 is rotatably mounted on both sides of the rotating table 514 via a shaft. The angle adjusting block 52 is provided with a cylinder connector 53 at the middle position of the rear side wall near the bottom. An angle adjusting cylinder is connected between the cylinder frame 512 and the cylinder connector 53. The angle adjusting block 52 is inserted into the adjusting square hole 513. The angle adjusting block 52 is provided with a connecting rod insertion hole 522. A bent connecting rod 54 is inserted into the connecting rod insertion hole 522. A graphite electrode sleeve 55 is fixed to the bottom end of the bent connecting rod 54.
[0041] The displacement cylinders 511 can pull the displacement box 51 back and forth, thereby moving the negative graphite electrode rod installed at the bottom. During the displacement process, the distance between the bottom end of the negative graphite electrode rod and the corresponding positive graphite electrode rod can be adjusted. The angle adjustment cylinder pushes the angle adjustment block 52 to rotate along the rotating beam 521, thereby achieving micro-angle changes, distance adjustment, and fine adjustment of the included angle.
[0042] The displacement box 51 can move 8-12mm within the first mounting square hole 221, the second mounting square hole 222 and the third mounting square hole 211, and the angle adjustment block 52 can adjust the maximum angle of 5°.
[0043] The distance cannot be too far, otherwise an electric arc cannot be generated. The angle is a fine adjustment because the distance adjustment is small. A large angle adjustment would cause the bottom of the negative graphite electrode rod to touch the corresponding positive graphite electrode rod, preventing the generation of an electric arc.
[0044] The lifting frame 1 includes a square sleeve 11, a square lifting column 12, and a lifting motor 13. The lifting motor 13 is embedded in the top of the square sleeve 11. A lead screw 131 is connected to the shaft of the lifting motor 13. The square lifting column 12 is inserted into the square sleeve 11 from the bottom. The lead screw 131 is inserted downward from the center of the top of the square lifting column 12.
[0045] The square lifting column 12 is raised or lowered by rotating the lead screw 131, thereby raising or lowering the discharge heating structure below.
[0046] The voltage difference between each group of positive graphite electrode rods 42 and the corresponding ring of negative graphite electrode rods is the same or increases gradually from top to bottom. Furthermore, the voltage difference needs to be designed and adjusted based on the distance between the bottom of the negative graphite electrode rod and the bottom of the corresponding positive graphite electrode rod.
[0047] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0048] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A quartz crucible melting apparatus, characterized in that: The system includes a lifting frame (1), a mounting plate (2), a positive electrode mounting assembly (4), and a negative electrode displacement assembly (5). The positive electrode mounting assembly (4) is mounted below the mounting plate (2) via a connecting rod assembly (414). The positive electrode mounting assembly (4) includes a positive electrode ceramic sleeve (41), on which three sets of positive electrode graphite electrode rods (42) are provided. The mounting plate (2) has three evenly spaced rings of negative electrode displacement assemblies (5). The negative electrode graphite electrode rods (3) mounted on each ring of the negative electrode displacement assembly (5) will be connected to each set of positive electrode graphite electrode rods (42). During discharge, the bottom of the negative graphite electrode rod on the outermost ring of the negative electrode displacement assembly (5) is arranged around the bottom of a positive graphite electrode rod (42) in the central group. The bottom of the negative graphite electrode rod (3) on the middle ring of the negative electrode displacement assembly (5) is arranged around the bottom of multiple positive graphite electrode rods (42) in the middle group. The bottom of the negative graphite electrode rod (3) on the innermost ring of the negative electrode displacement assembly (5) is arranged around the bottom of multiple positive graphite electrode rods (42) in the outermost group. The bottom of the negative graphite electrode rod (3) will form a cone-shaped discharge tower after surrounding the bottom of the positive graphite electrode rod (42).
2. The quartz crucible melting equipment according to claim 1, characterized in that, The mounting plate (2) includes a disc (21), a plurality of mounting strips (22) evenly distributed around the disc (21), and an upward-facing cylinder (20) at the center of the disc (21). Each mounting strip (22) has a first mounting square hole (221) and a second mounting square hole (222) respectively from the outermost end inward. The disc (21) has a third mounting square hole (211) between adjacent mounting strips (22). The first negative electrode graphite electrode rod (31) is installed on the negative electrode displacement component (5) in the first mounting square hole (221), the second negative electrode graphite electrode rod (32) is installed on the negative electrode displacement component (5) in the second mounting square hole (222), and the third negative electrode graphite electrode rod (33) is installed on the negative electrode displacement component (5) in the third mounting square hole (211). The positive electrode ceramic sleeve (41) includes a core column (411), a first winding column (412), and a second winding column (413). The upper half of the outer wall of the core column (411) is evenly surrounded by multiple first winding columns (412). A second winding column (413) is fixedly provided on the upper half of each adjacent first winding column (412). A first positive electrode graphite electrode rod, a second positive electrode graphite electrode rod, and a third positive electrode graphite electrode rod are respectively passed through the core column (411), the first winding column (412), and the second winding column (413).
3. The quartz crucible melting equipment according to claim 2, characterized in that, The first positive graphite electrode rod, the second positive graphite electrode rod, and the third positive graphite electrode rod all have their bottom discharge ends exposed at the bottom ends of the core rod (411), the first winding rod (412), and the second winding rod (413); The first negative graphite electrode rod (31), the second negative graphite electrode rod (32) and the third negative graphite electrode rod (33) are all coated with an insulating ceramic layer at the discharge end of the bottom. The discharge ends of all positive graphite electrodes (42) and all negative graphite electrode rods are tapered discharge ends.
4. The quartz crucible melting equipment according to claim 3, characterized in that, There is only one first positive graphite electrode rod. The second and third positive graphite electrode rods have the same diameter and number, and there are no fewer than four of them. The diameter of the first positive graphite electrode rod is more than twice the diameter of the second positive graphite electrode rod. The first negative graphite electrode rod (31), the second negative graphite electrode rod (32) and the third negative graphite electrode rod (33) have the same diameter and number, and their diameter and number are the same as those of the second positive graphite electrode rod.
5. The quartz crucible melting equipment according to claim 3, characterized in that, The distance between the bottom ends of the first positive graphite electrode rod and the second positive graphite electrode rod, and the distance between the bottom ends of the second positive graphite electrode rod and the third positive graphite electrode rod, are both not less than 10 cm. The distance between the bottom ends of the first positive graphite electrode rod and the third positive graphite electrode rod is not less than half the height of the inner cavity of the quartz crucible.
6. The quartz crucible melting equipment according to claim 1, characterized in that, The negative electrode displacement assembly (5) includes a displacement box (51), an angle adjustment block (52), and a graphite electrode sleeve (55). The top two sides of the displacement box (51) are mounting plates. A displacement cylinder (511) assembly is provided on the rear side of the displacement box (51) near the top. The displacement box (51) has an adjustment square hole (513) that runs vertically through it. A rotating platform (514) is provided on the inner rear wall of the adjustment square hole (513) near the top. A cylinder bracket (512) is installed on the rear wall of the displacement box (51) near the bottom. A rotating beam is provided on the rear wall of the angle adjustment block (52) near the top. (521) The rotating beam (521) is rotatably mounted on both sides of the rotating table (514) via a shaft. The angle adjusting block (52) is provided with a cylinder connector (53) at the middle position of the rear side wall near the bottom. An angle adjusting cylinder is connected between the cylinder frame (512) and the cylinder connector (53). The angle adjusting block (52) is inserted into the adjusting square hole (513). The angle adjusting block (52) is provided with a connecting rod insertion hole (522). A bent connecting rod (54) is inserted into the connecting rod insertion hole (522). A graphite electrode sleeve (55) is fixed at the bottom end of the bent connecting rod (54).
7. The quartz crucible melting equipment according to claim 6, characterized in that, The displacement box (51) moves 8-12 mm within the first mounting square hole (221), the second mounting square hole (222), and the third mounting square hole (211), and the angle adjustment block (52) can adjust the maximum angle of 5°.
8. The quartz crucible melting equipment according to claim 1, characterized in that, The lifting frame (1) includes a square sleeve (11), a square lifting column (12) and a lifting motor (13). The lifting motor (13) is embedded in the top of the square sleeve (11). A lead screw (131) is connected to the shaft of the lifting motor (13). The square lifting column (12) is inserted into the square sleeve (11) from the bottom. The lead screw (131) is inserted downward from the center of the top of the square lifting column (12).
9. The quartz crucible melting equipment according to claim 1, characterized in that, The voltage difference between each group of positive graphite electrode rods (42) and the corresponding ring of negative graphite electrode rods is the same or increases gradually from top to bottom.