Thermal insulation structure for crucible shaft of silicon core furnace

Abstract

The utility model provides a heat insulation structure for a crucible shaft of a silicon core furnace, and relates to the technical field of silicon core drawing. The heat insulation device comprises a furnace bottom plate with a through hole, a graphite supporting rod is arranged in the through hole, a crucible shaft is coaxially connected with the bottom end of the graphite supporting rod, a corrugated pipe is arranged at the bottom of the furnace bottom plate and covers the crucible shaft and the graphite supporting rod, and an upper heat insulation sleeve and a lower heat insulation sleeve which are coaxially connected in a sliding mode are arranged on the inner side of the corrugated pipe. The top end of the upper heat insulation sleeve is connected with the bottom of the furnace bottom plate, and the graphite supporting rod and the crucible shaft are located on the inner side of the upper heat insulation sleeve and the inner side of the lower heat insulation sleeve. The heat insulation part is arranged between the corrugated pipe and the sliding track of the graphite supporting rod, so that the corrugated pipe is prevented from being damaged.

Description

TECHNICAL FIELD

[0001] The utility model relates to silicon core drawing technical field, concretely relates to a silicon core furnace crucible axle heat insulation structure. BACKGROUND

[0002] In the photovoltaic field, the growth of polycrystalline silicon needs to use silicon core, one of which is round silicon core, in the round silicon core drawing process, the silicon material will be melted (above 1600 DEG C) in the crucible, and the crucible will be lifted and lowered with the growth of silicon core. The lifting and lowering of the crucible is to realize drawing by driving the graphite support rod to lift and lower the crucible, and the drawing process is in a vacuum state, so a thin-walled bellows (thickness is 0.2mm) with tensile and compressive properties is configured as a vacuum protection structure.

[0003] In the silicon core drawing operation process, the bellows will be repeatedly stretched and compressed with the lifting and lowering of the crucible. When the crucible position drops to the lowest position, the graphite support rod will drop to the inside of the bellows, at this time the bellows reaches the maximum stretching limit, high temperature will bake the bellows, accelerate the service life of the bellows, and easily cause the bellows to produce thermal fatigue phenomenon, eventually cause the bellows to be damaged and leak, and seriously cause the support rod to be oxidized and corroded to produce silicon leakage risk, and cause major safety hazards and property losses. UTILITY MODEL CONTENTS

[0004] The utility model aims at developing a silicon core furnace crucible axle heat insulation structure which sets a heat insulation part between the sliding track of the bellows and the graphite support rod to avoid damage of the bellows.

[0005] The utility model realizes the following technical scheme:

[0006] A silicon core furnace crucible axle heat insulation structure, comprising:

[0007] A furnace bottom plate with a through hole;

[0008] A graphite support rod arranged in the through hole;

[0009] A crucible axle coaxially connected with the bottom end of the graphite support rod;

[0010] A bellows arranged at the bottom of the furnace bottom plate and covering the crucible axle and the graphite support rod inside;

[0011] Wherein, the inside of the bellows is provided with an upper heat insulation sleeve and a lower heat insulation sleeve coaxially and slidingly connected, the top end of the upper heat insulation sleeve is connected with the bottom of the furnace bottom plate, and the graphite support rod and the crucible axle are inside the upper heat insulation sleeve and the lower heat insulation sleeve.

[0012] Optionally, the upper heat insulation sleeve and the lower heat insulation sleeve are both in the form of a cylinder and are coaxial with the through hole.

[0013] Optionally, the upper heat insulation sleeve top end is coaxially connected with a first flange, and the first flange is connected with the furnace bottom plate.

[0014] Optionally, a first sealing groove is arranged on the top end surface of the first flange in contact with the furnace bottom plate, and a first sealing ring is arranged in the first sealing groove.

[0015] Optionally, the lower heat insulation sleeve is sleeved outside the upper heat insulation sleeve, and a limiting assembly is arranged between the lower heat insulation sleeve top end and the upper heat insulation sleeve bottom end.

[0016] Optionally, the limiting assembly comprises an upper step protruding inwardly at the lower heat insulation sleeve top end and a lower step protruding outwardly at the upper heat insulation sleeve bottom end, the inner diameter of the upper step is matched with the outer diameter of the upper heat insulation sleeve, and the outer diameter of the lower step is matched with the inner diameter of the lower heat insulation sleeve.

[0017] Optionally, the top edge of the inner wall of the upper step is rounded, and the bottom edge of the outer wall of the lower step is rounded.

[0018] Optionally, the lower heat insulation sleeve bottom end is provided with an inwardly protruding inner edge, and the inner diameter of the inner edge is not less than the outer diameter of the crucible shaft.

[0019] Optionally, the bellows top end is coaxially connected with a second flange, the top surface of the second flange is provided with a second sealing groove, a second sealing ring is arranged in the second sealing groove, and the second flange is connected with the first flange.

[0020] Optionally, the thickness of the upper heat insulation sleeve and the lower heat insulation sleeve is 2-5 mm, and the material of the upper heat insulation sleeve and the lower heat insulation sleeve is 304, 316 or 310S stainless steel.

[0021] The beneficial effects of the utility model are:

[0022] The upper heat insulation sleeve and the lower heat insulation sleeve arranged in cooperation work can avoid that the bellows top end is baked by high temperature, prevent the annealing softening, oxidation and coloration and irreversible plastic deformation damage of the bellows caused by high temperature of the graphite supporting rod, compared with the heat insulation components including the water cooling sleeve structure, the utility model has lower cost, simpler structure, no water leakage hidden danger and is safer. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0024] Figure 1 It is a structure diagram of the utility model crucible stroke at the lower limit.

[0025] Figure 2 The structure diagram of the crucible stroke at the upper limit position of the utility model;

[0026] Figure 3 For Figure 1 The enlarged view at A in the middle.

[0027] Reference signs: 1, furnace bottom plate; 2, through hole; 3, graphite support rod; 4, crucible shaft; 5, first flange; 6, upper heat insulation sleeve; 7, lower heat insulation sleeve; 8, second flange; 9, corrugated pipe; 10, inner edge; 11, collar; 12, support plate; 13, upper step; 14, lower step. DETAILED DESCRIPTION

[0028] In the following, only certain exemplary embodiments are simply described. As those skilled in the art can realize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the drawings and the description are considered to be essentially exemplary rather than limiting.

[0029] In the description of the present invention, it needs to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present invention.

[0030] The embodiments of the utility model will be described in detail below in combination with the drawings.

[0031] As Figures 1-3 shown, the utility model discloses a kind of silicon core furnace crucible shaft heat insulation structure, including furnace bottom plate 1, furnace bottom plate 1 is equipped with through hole 2, through hole 2 is equipped with the graphite support rod 3 of lift and crucible shaft 4 of lift, crucible shaft 4 is coaxially connected in graphite support rod 3 bottom end, crucible shaft 4 outer diameter is greater than graphite support rod 3, crucible shaft 4 lift drives graphite support rod 3 to lift.

[0032] The lower part of the through hole 2 is provided with a cylindrical upper heat insulation sleeve 6, and the top of the upper heat insulation sleeve 6 is coaxially provided with a first flange 5, the inner diameter of the first flange 5 and the upper heat insulation sleeve 6 is matched with the inner diameter of the through hole 2, the first flange 5 is arranged on the bottom of the furnace bottom plate 1 and is coaxially connected with the through hole 2, and the upper heat insulation sleeve 6 is sleeved outside the sliding track of the graphite supporting rod 3 and the crucible shaft 4. The top end surface of the first flange 5 in contact with the furnace bottom plate 1 is provided with a first sealing groove, and the first sealing groove is provided with a first sealing ring.

[0033] The outer part of the upper heat insulation sleeve 6 is sleeved with a lower heat insulation sleeve 7, the lower heat insulation sleeve 7 is cylindrical and coaxially connected with the upper heat insulation sleeve 6, and the inner diameter of the lower heat insulation sleeve 7 is larger than the outer diameter of the upper heat insulation sleeve 6. A limiting assembly is arranged between the top end of the lower heat insulation sleeve 7 and the bottom end of the upper heat insulation sleeve 6, so that the lower heat insulation sleeve 7 cannot slide out of the upper heat insulation sleeve 6.

[0034] The limiting assembly includes an upper step 13 protruding inward at the top end of the lower heat insulation sleeve 7, the upper step 13 is annular around the inner edge of the top end of the lower heat insulation sleeve 7, the inner diameter of the upper step 13 is matched with the outer diameter of the upper heat insulation sleeve 6, and the top edge of the inner wall of the upper step 13 is rounded.

[0035] The limiting assembly further includes a lower step 14 protruding outward at the bottom end of the upper heat insulation sleeve 6, the lower step 14 is annular around the outer edge of the bottom end of the upper heat insulation sleeve 6, the outer diameter of the lower step 14 is matched with the inner diameter of the lower heat insulation sleeve 7, and the bottom edge of the outer wall of the lower step 14 is rounded.

[0036] The arrangement of the upper step 13 and the lower step 14 not only avoids the lower heat insulation sleeve 7 from sliding out of the upper heat insulation sleeve 6, but also serves as a sliding guide component between the lower heat insulation sleeve 7 and the upper heat insulation sleeve 6, so that the lower heat insulation sleeve 7 slides coaxially on the upper heat insulation sleeve 6.

[0037] The bottom end of the lower heat insulation sleeve 7 is provided with an inwardly protruding inner edge 10, and the inner diameter of the inner edge 10 is not less than the outer diameter of the crucible shaft 4. By arranging the inner edge 10 at the bottom end of the lower heat insulation sleeve 7, the gap between the bottom end of the lower heat insulation sleeve 7 and the crucible shaft 4 is small or non-existent. The lower part of the crucible shaft 4 is provided with a sleeve ring 11, and the outer diameter of the sleeve ring 11 is larger than the inner diameter of the inner edge 10.

[0038] The thickness of the upper heat insulation sleeve 6 and the lower heat insulation sleeve 7 is 2-5mm, and the material is 304, 316 or 310S high-temperature stainless steel.

[0039] The outer part of the upper heat insulation sleeve 6 and the lower heat insulation sleeve 7 is provided with a corrugated pipe 9, the corrugated pipe 9 is in a coaxial state with the through hole 2, the top end of the corrugated pipe 9 is coaxially connected with a second flange 8, the top surface of the second flange 8 is provided with a second sealing groove, the second sealing groove is provided with a second sealing ring, and the second flange 8 is connected with the first flange 5. The outer side of the sleeve ring 11 is connected with a support plate 12, and the bottom end of the corrugated pipe 9 is connected with the support plate 12.

[0040] Figure 1As shown, when the crucible stroke is at the lower limit, the graphite support rod 3 is lowered to the position of the through hole 2, the lower heat shield 7 is lowered to the bottom end under the action of its own gravity, the upper step 13 is in contact with the lower step 14, at this time, the telescopic cylindrical heat insulation structure formed by the lower heat shield 7 and the upper heat shield 6 is in an elongated state, the graphite support rod 3 is covered inside to achieve the effect of heat insulation, and the corrugated pipe 9 is protected.

[0041] Figure 2 As shown, when the crucible stroke is at the upper limit, the graphite support rod 3 enters the through hole 2, at this time, the graphite support rod 3 and the corrugated pipe 9 do not have an overlapping area, the bottom end of the lower heat shield 7 is pushed to slide upward to the top end during the process that the support plate 12 and the sleeve ring 11 are raised with the crucible shaft 4, at this time, the telescopic cylindrical heat insulation structure formed by the lower heat shield 7 and the upper heat shield 6 is in a shortened state, and the lifting of the crucible shaft 4 and the graphite support rod 3 is not affected.

[0042] The upper heat shield 6 and the lower heat shield 7 are cooperatively arranged, the top end of the corrugated pipe 9 is avoided from being baked by high temperature, the annealing softening, oxidation and coloration and irreversible plastic deformation damage of the corrugated pipe 9 caused by high temperature of the graphite support rod 3 are avoided, compared with heat insulation components including a water cooling jacket structure, the utility model has lower cost, simpler structure, no water leakage hidden danger and higher safety.

[0043] The above-mentioned embodiments are only preferred embodiments of the utility model, and are not a limitation on the technical scheme of the utility model, and as long as a technical scheme can be realized on the basis of the above-mentioned embodiments without creative labor, it should be considered that the technical scheme falls within the protection scope of the utility model patent.

Claims

1. A silicon core furnace crucible shaft insulation structure, characterized by, The utility model relates to a graphite crucible shaft supporting device, including: The furnace bottom plate has a through hole; The graphite supporting rod is arranged in the through hole; The crucible shaft is coaxially connected with the bottom end of the graphite supporting rod; The bellows is arranged at the bottom of the furnace bottom plate and covers the crucible shaft and the graphite supporting rod inside; The upper heat insulation sleeve and the lower heat insulation sleeve are coaxially and slidingly connected inside the bellows, the top end of the upper heat insulation sleeve is connected with the bottom of the furnace bottom plate, and the graphite supporting rod and the crucible shaft are inside the upper heat insulation sleeve and the lower heat insulation sleeve.

2. The silicon core furnace crucible shaft insulation structure according to claim 1, characterized by, The upper heat insulation sleeve and the lower heat insulation sleeve are both cylindrical and coaxial with the through hole.

3. The silicon core furnace crucible shaft insulation structure according to claim 2, wherein The top end of the upper heat insulation sleeve is coaxially connected with a first flange, and the first flange is connected with the furnace bottom plate.

4. The silicon core furnace crucible shaft insulation structure according to claim 3, characterized by A first sealing groove is arranged on the top end surface of the first flange in contact with the furnace bottom plate, and a first sealing ring is arranged in the first sealing groove.

5. The silicon core furnace crucible shaft insulation structure according to claim 2, wherein The lower heat insulation sleeve is slidingly arranged outside the upper heat insulation sleeve, and a limiting assembly is arranged between the top end of the lower heat insulation sleeve and the bottom end of the upper heat insulation sleeve.

6. The silicon core furnace crucible shaft insulation structure according to claim 5, wherein The limiting assembly includes an upper step protruding inwardly at the top end of the lower heat insulation sleeve and a lower step protruding outwardly at the bottom end of the upper heat insulation sleeve, the inner diameter of the upper step is adapted to the outer diameter of the upper heat insulation sleeve, and the outer diameter of the lower step is adapted to the inner diameter of the lower heat insulation sleeve.

7. The silicon core furnace crucible shaft insulation structure according to claim 6, wherein The top edge of the inner wall of the upper step is rounded, and the bottom edge of the outer wall of the lower step is rounded.

8. The silicon core furnace crucible shaft insulation structure according to claim 2, wherein The bottom end of the lower heat insulation sleeve is provided with an inwardly protruding inner rim, and the inner diameter of the inner rim is not less than the outer diameter of the crucible shaft.

9. The silicon core furnace crucible shaft insulation structure according to claim 3, wherein The top end of the bellows is coaxially connected with a second flange, the top surface of the second flange is provided with a second sealing groove, a second sealing ring is arranged in the second sealing groove, and the second flange is connected with the first flange.

10. The silicon core furnace crucible shaft insulation structure according to any one of claims 1 to 9, characterized by The thickness of the upper heat insulation sleeve and the lower heat insulation sleeve is 2-5 mm, and the material of the upper heat insulation sleeve and the lower heat insulation sleeve is 304, 316 or 310S stainless steel.

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