Thermal insulation cylinder and single crystal furnace

Abstract

The utility model relates to the field of material high-temperature treatment equipment, and discloses a heat preservation cylinder and a single crystal furnace, the heat preservation cylinder comprises at least two cylindrical heat preservation layers which are mutually nested inside and outside, and the surface of the heat preservation layer closest to a heater is uniformly coated with a high-temperature-resistant insulating coating. According to the thermal insulation cylinder, the distance between the inner wall of the thermal insulation cylinder and the heater is reduced by arranging the inner thermal insulation layer, and heat loss is reduced, so that energy consumption during single crystal preparation of the single crystal furnace is reduced, and the preparation cost of the single crystal is reduced. Meanwhile, the surface of the closest thermal insulation layer is coated with the high-temperature-resistant insulating coating, so that accidents such as ignition caused by too close distance between the thermal insulation layer and the heater can be avoided, the heater is prevented from being damaged by the ignition phenomenon, and the preparation cost of the single crystal is further reduced.

Description

Technical Field

[0001] The utility model relates to the field of high-temperature material processing equipment, in particular to a heat preservation tube and a single crystal furnace. Background Art

[0002] With the continuous development of the photovoltaic industry, the market demand for single crystals has gradually increased, resulting in the continuous increase in the size and length of the crystal rods during the preparation of single crystals, the size of the components in the single crystal furnace has also been continuously expanded, and the performance requirements for insulation materials have become increasingly higher. The existing single crystal furnace equipment, due to the increase in equipment size, has increased the distance between the insulation tube and the heater, resulting in serious heat loss. Too close a distance can easily cause accidents such as ignition of the heater, causing damage to the heater, and increasing the production cost in the single crystal preparation process. Utility Model Content

[0003] In order to overcome the shortcomings of the prior art, the purpose of the utility model is to provide a heat preservation tube, which can reduce the distance between the heat preservation tube and the heater, avoid heat loss, and avoid ignition accidents of the heater due to the close distance between the heat preservation tube and the heater, avoid damage to the heater, and reduce the production cost of single crystals.

[0004] To solve the above problems, the technical solution adopted by the utility model is as follows: an insulation cylinder is arranged outside the crucible and heater of the single crystal furnace, including at least two layers of tubular insulation layers nested inside and outside each other, and the surface of the insulation layer closest to the heater is evenly coated with a high-temperature resistant insulating coating.

[0005] Compared with the prior art, the utility model has the beneficial effect that: by setting a plurality of nested insulation layers, the inner diameter of the insulation tube is reduced, so that the distance between the inner wall of the insulation tube and the heater is closer. At the same time, the surface of the insulation layer closest to the heater is evenly coated with a high-temperature resistant insulating coating, which can prevent the inner wall of the insulation tube from being too close to the heater, causing the heater to ignite, avoid damaging the heater, reduce the energy consumption of the single crystal furnace, and reduce the preparation cost of the single crystal.

[0006] In the above-mentioned heat-insulating cylinder, the height of the heat-insulating layer close to the heater is higher than the height of the heat-insulating layer far from the heater.

[0007] In the above-mentioned heat-insulating cylinder, the height of the heat-insulating layer close to the heater is 20-50 mm higher than the height of the heat-insulating layer far from the heater.

[0008] In the above-mentioned heat-insulating cylinder, the heat-insulating layer on the inner side is formed by splicing a plurality of heat-insulating boards.

[0009] In the above-mentioned heat-insulating cylinder, the heat-insulating layer on the inner side is composed of an upper structure and a lower structure, and the upper structure and the lower structure are both composed of four heat-insulating plates of the same size.

[0010] In the above-mentioned heat-insulating cylinder, a supporting structure is arranged between each of the heat-insulating layers.

[0011] In the above-mentioned thermal insulation tube, the support structure includes a first support flange arranged in the middle of the thermal insulation layer and a second support flange arranged at the bottom of the thermal insulation layer, and the first support flange and the second support flange are both arranged on the side of the thermal insulation layer facing inward.

[0012] In the above-mentioned heat preservation tube, the thickness of the first supporting flange and the second supporting flange are both in the range of 10-30 mm, and the width of the first supporting flange and the second supporting flange are both in the range of 20-40 mm.

[0013] In the above-mentioned heat-insulating cylinder, the cross-sectional shape of the heat-insulating layer is a regular circle or a regular polygon.

[0014] A single crystal furnace, wherein the above-mentioned heat preservation cylinder is arranged outside the crucible and the heater.

[0015] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of a heat preservation cylinder according to a first embodiment of the present utility model;

[0017] Figure 2 It is a schematic diagram of the layer section of the thermal insulation board of the embodiment of the utility model;

[0018] Figure 3 This is a schematic structural diagram of the outer insulation layer of the first embodiment of the utility model;

[0019] Figure 4 This is a schematic structural diagram of the inner thermal insulation layer of the first embodiment of the utility model;

[0020] Figure 5 A top view of a heat preservation cylinder according to a second embodiment of the present utility model;

[0021] Figure 6 It is a cross-sectional view of the lower furnace body of the single crystal furnace according to an embodiment of the present utility model.

[0022] Description of Figure Numbers:

[0023] 100 insulation cylinder, 110 outer insulation layer, 111 support structure, 1111 first support flange, 1112 second support flange, 120 inner insulation layer, 121 insulation board, 1211 insulation coating, 200 crucible, 300 heater. DETAILED DESCRIPTION

[0024] The embodiments of the present invention are described in detail below. Figure 1and Figure 2 The embodiment of the utility model provides an insulation cylinder 100, which is arranged outside the heater 300 and the crucible 200 of the single crystal furnace, and is used to prevent the heat dissipated by the heater 300 from being lost, so that the temperature of the crucible 200 can rise to the required temperature. The insulation cylinder 100 includes at least two layers of tubular insulation layers nested inside and outside, wherein the surface of the insulation layer closest to the heater 300 is uniformly coated with a high-temperature resistant insulating coating 1211. The insulation cylinder 100 of the embodiment of the utility model reduces the distance between the inner wall of the insulation cylinder 100 and the heater 300 by nesting the insulation layer inside the original insulation layer, thereby avoiding the heat loss caused by the excessive distance between the insulation cylinder 100 and the heater 300 in the large-size single crystal preparation equipment, resulting in the need for higher power to raise the temperature of the crucible 200 to the required temperature, thereby reducing the energy consumption in the single crystal preparation process and reducing the cost. At the same time, the surface of the insulation layer closest to the heater 300 is evenly coated with a high-temperature resistant insulating coating 1211 to prevent the insulation tube 100 from being too close to the heater 300, causing accidents such as ignition of the heater 300, thereby avoiding damage to the heater 300 and further reducing the production cost of single crystal preparation.

[0025] It is understandable that the insulation layer is generally made of graphite felt or carbon felt, and the insulation coating 1211 can be made of high-temperature resistant ceramic coating or high-temperature epoxy insulation paint and other high-temperature resistant insulation coatings, and is evenly coated on the surface of the insulation layer closest to the heater 300 in a staggered manner. During the coating process, the two coating processes are applied in the axial and radial directions of the insulation layer respectively. After each coating, the applied insulation layer needs to be placed in a ventilated environment and left to stand at room temperature for 48-60 hours to dry naturally. The coating process should be applied as slowly as possible to avoid bubbling. If the surface is found to be uneven or peeling after drying, a second re-coating is required. During the second re-coating, a small amount should be applied as much as possible to avoid affecting the surrounding materials.

[0026] In some embodiments, in order to prevent the dust generated by the long-term high-temperature pulverization of the soft felt wrapped around the outer surface of the insulation tube 100 from entering the interior of the heater 300, the height of the insulation layer close to the heater 300 needs to be higher than the height of the insulation layer far from the heater 300. At the same time, in order to facilitate the installation of the insulation layer close to the inner layer, the insulation layer of the inner layer is spliced ​​by multiple insulation boards 121. Since the area size of a single insulation board 121 is small, it is convenient to process and apply the insulating coating 1211, and it is convenient to ensure the consistency of the size and thickness of the insulation board 121, so that the thickness of the spliced ​​insulation layer is uniform, so that the temperature of the temperature field in the entire insulation tube 100 is more uniform.

[0027] In some embodiments, in order to ensure the structural strength of the thermal insulation tube 100, a support structure 111 is provided between the thermal insulation layers. It is understood that the support structure 111 can be a bracket or a support block provided between the thermal insulation layers, and the width of the support structure 111 needs to be set according to the spacing between the thermal insulation layers. It is understood that in order to further improve the uniformity of the temperature in the thermal insulation tube 100, the cross-section of the thermal insulation layer is preferably a regular circle or a regular polygon.

[0028] Example 1: In Example 1, refer to Figure 1 The insulation tube 100 includes two insulation layers, an outer insulation layer 110 and an inner insulation layer 120. Since the heater 300 in the single crystal furnace body is generally arranged inside the insulation tube 100, the height of the inner insulation layer 120 is 20-50 mm higher than the height of the outer insulation layer 110. The surface of the inner insulation layer 120 is coated with a high temperature resistant insulating coating 1211. The outer insulation layer 110 and the inner insulation layer 120 are both cylinders with a perfect circular cross section. The diameter of the outer insulation layer 110 is 1140±0.5 mm, the thickness is 15±0.5 mm, and the height is 545-565 mm. The diameter of the inner insulation layer 120 is 1110±0.5 mm, the thickness is 10±0.5 mm, and the height is 565-585 mm. A 5 mm gap is set between the inner insulation layer 120 and the outer insulation layer 110.

[0029] In Example 1, referring to Figure 4 The inner insulation layer 120 is composed of an upper structure and a lower structure, and the upper structure and the lower structure are surrounded by four insulation boards 121 with a quarter arc length. The method used when applying the insulation coating 1211 to each insulation board 121 needs to be consistent to ensure the consistency of the size and thickness of the insulation board 121, so as to improve the uniformity of the temperature in the insulation cylinder 100.

[0030] In Example 1, referring to Figure 3The support structure 111 includes a first support flange 1111 disposed in the middle of the outer insulation layer 110 and a second support flange 1112 disposed at the bottom of the outer insulation layer 110. The first support flange 1111 and the second support flange 1112 are both disposed on the inner side of the outer insulation layer 110 and extend toward the inner insulation layer 120. The thickness of the first support flange 1111 and the second support flange 1112 is between 10-30 mm and the width is between 20-40 mm. The first support flange 1111 is embedded in the inner surface of the outer insulation layer 110 with an embedding depth of between 5-10 mm, and is connected to the lower edge of the upper structure of the inner insulation layer 120 and the upper edge of the lower structure. The second support flange 1112 is formed by extending inward from the lower edge of the outer insulation layer 110. The second support flange 1112 is connected to the lower edge of the lower structure of the inner insulation layer 120. The width of the first support flange 1111 and the second support flange 1112 is in the range of 20-40 mm.

[0031] Example 2: Reference Figure 5 The difference between the insulation tube 100 of Example 2 and the insulation tube 100 of Example 1 is that the cross-section of the insulation layer is a regular quadrilateral, and the upper structure and the lower structure of the inner insulation layer 120 are respectively composed of four rectangular insulation boards 121 with equal length and width.

[0032] The lower furnace body of the single crystal furnace of the utility model embodiment is as follows Figure 6 As shown, the above-mentioned heat preservation tube 100, crucible 200 and heater 300 composed of graphite electric heating element are all arranged inside the heat preservation tube 100, and the heater 300 is arranged between the heat preservation tube 100 and the crucible 200 to prevent the heat generated by the heater 300 from being lost, so that the silicon in the crucible 200 is melted. The single crystal furnace of the utility model embodiment can avoid the heat loss caused by the large distance between the heat preservation tube 100 and the heater 300, reduce the energy consumption in the single crystal preparation process, and reduce the preparation cost of the single crystal. At the same time, the high temperature resistant insulating coating 1211 on the surface of the heat preservation layer 120 in the heat preservation tube 100 can prevent the heat preservation tube 100 and the heater 300 from being too close to cause ignition and other accidents, avoid damage to the heater 300, and further reduce the preparation cost of the single crystal.

[0033] It should be noted that in the description of the present invention, if there are any orientation descriptions, such as up, down, front, back, left, right, etc., the orientations or positional relationships indicated are all based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and cannot be understood as a limitation on the present invention.

[0034] In the description of the present utility model, "several" means one or more, "more" means two or more, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0035] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0036] The above-mentioned implementation modes are only preferred implementation modes of the present invention, and cannot be used to limit the protection scope of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A heat preservation cylinder, arranged outside a crucible (200) and a heater (300) of a single crystal furnace, characterized in that: It comprises at least two layers of tubular heat-insulating layers which are nested inside and outside each other, wherein the surface of the heat-insulating layer closest to the heater (300) is evenly coated with a high-temperature resistant insulating coating (1211).

2. The heat preservation cylinder according to claim 1, characterized in that: The height of the heat-insulating layer close to the heater (300) is higher than the height of the heat-insulating layer far from the heater (300).

3. The heat preservation cylinder according to claim 2, characterized in that: The height of the heat-insulating layer close to the heater (300) is 20-50 mm higher than the height of the heat-insulating layer far from the heater (300).

4. The heat preservation cylinder according to claim 1, characterized in that: The inner insulation layer is formed by splicing a plurality of insulation boards (121).

5. The heat preservation cylinder according to claim 4, characterized in that: The inner insulation layer is composed of an upper structure and a lower structure, and the upper structure and the lower structure are both composed of four insulation boards (121) of the same size.

6. The heat preservation cylinder according to claim 1, characterized in that: A supporting structure (111) is arranged between each of the thermal insulation layers.

7. The heat preservation cylinder according to claim 6, characterized in that: The support structure (111) comprises a first support flange (1111) arranged in the middle of the thermal insulation layer and a second support flange (1112) arranged at the bottom of the thermal insulation layer, wherein the first support flange (1111) and the second support flange (1112) are both arranged on the side of the thermal insulation layer facing inward.

8. The heat preservation cylinder according to claim 7, characterized in that: The thickness of the first supporting flange (1111) and the second supporting flange (1112) are both in the range of 10-30 mm, and the width of the first supporting flange (1111) and the second supporting flange (1112) are both in the range of 20-40 mm.

9. The heat preservation cylinder according to claim 1, characterized in that: The cross-sectional shape of the thermal insulation layer is a regular circle or a regular polygon.

10. A single crystal furnace, characterized in that: The crucible (200) and the heater (300) are provided with a heat preservation cylinder (100) according to any one of claims 1 to 9.

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