CN215328447U

CN215328447U - Sintering hearth for synthesizing crystal by flame fusion method

Info

Publication number: CN215328447U
Application number: CN202121360083.7U
Authority: CN
Inventors: 陈珍富; 唐大林
Original assignee: Sichuan Jiubao Crystal Technology Co ltd
Current assignee: Sichuan Jiubao Crystal Technology Co ltd
Priority date: 2021-06-18
Filing date: 2021-06-18
Publication date: 2021-12-28
Anticipated expiration: 2031-06-18

Abstract

The utility model discloses a sintering hearth for synthesizing crystals by a flame fusion method, which comprises a hearth shell, a heat-insulating layer and an inner furnace wall which are sequentially arranged from outside to inside, wherein a crystal growth space in the inner furnace wall is of a spindle-shaped curve structure, and the maximum diameter of the crystal growth space is the growth length of the crystals. According to the utility model, the crystal growth space in the inner furnace wall is improved into a spindle-shaped curve structure, and the growth position of the crystal is located at the maximum diameter position of the crystal growth space, so that the crystal has enough growth space during transverse growth and can not touch the inner wall of the inner furnace wall any more, and the crystal can be completely grown in the transverse direction. According to the utility model, the internal crystal growth space of the inner furnace wall is set to be of a spindle-shaped curve structure, and compared with a common cone frustum-shaped structure, the size change of the internal crystal growth space from top to bottom is large, so that the entering of powder is not influenced, and the crystal has a large enough transverse growth space.

Description

Sintering hearth for synthesizing crystal by flame fusion method

Technical Field

The utility model relates to a sintering hearth for synthesizing crystals by a flame fusion method.

Background

The flame fusion process, also known as Verneuilprocess, is one of the methods for artificially producing single crystals from a melt. The prepared fine powder of the raw materials leaks from a pipe orifice, is uniformly sprayed in oxyhydrogen flame to be melted, and is then condensed and crystallized on the top layer of a seed crystal or a pear-shaped monocrystal; the growth of the pear crystals starts from a cone melted at the top, the base of the pear crystals descends and rotates in the growth process so as to ensure that the melting surface of the pear crystals grows layer by layer at a proper temperature, and the artificial gem crystallized while rotating has arc growth grains or color bands like the sing-slip grains and the characteristics of bead-shaped and tadpole-shaped bubbles and the like; the method without using crucible can prepare various artificial gems such as synthetic ruby, sapphire, spinel, rutile and artificial strontium titanate with low cost.

The term "single crystal" means that the particles within a crystal are regularly and periodically arranged in three dimensions, or the crystal as a whole is formed of a three-dimensional lattice of identical spaces, and the particles are spatially arranged in long-range order throughout the crystal. The entire crystal lattice of a single crystal is continuous and has important industrial applications. Because entropy effects lead to non-idealities in the solid microstructure, such as impurities, non-uniform strain and crystal defects, ideal single crystals of a certain size are extremely rare in nature and are also difficult to produce in the laboratory. On the other hand, in nature, undesirable single crystals can be very large, for example, some minerals such as emeralds, gypsums, feldspars are known to form crystals of up to several meters.

As shown in figure 1, a sintering hearth used for crystal growth by a traditional flame fusion method is formed by combining a seamless steel pipe, heat-insulating cotton, corundum sand and a trapezoidal core rod mold, and the whole structure of the sintering hearth is divided into a hearth shell 1, a heat-insulating layer 2, an inner furnace wall 3 and a crystal growth space (namely the space where a core rod mold 4 is located). The using method comprises the steps of vertically fixing a trapezoidal core rod mold at the axis of a section of seamless steel pipe, arranging and compacting heat insulation cotton around the inner wall of the seamless steel pipe, adding mixed corundum sand of adhesive into a space formed by the heat insulation layer and the trapezoidal core rod mold, compacting by gravity to form an inner furnace wall layer, and finally taking out the trapezoidal core rod mold to finish the manufacturing of the traditional sintering furnace. The crystal growth space made by the trapezoidal core rod die is a trapezoidal space with a small top and a large bottom, crystals grow in the crystal growth process, powder is fan-shaped during blanking and cannot be completely used for crystal growth, a part of powder scatters around the inner furnace wall to form a layer of semi-crystalline object through adhesion, and is not easy to remove, the crystal growth space is smaller and smaller as time passes, when the transverse growth diameter of the crystals is too large, the crystals are cracked due to the fact that the crystals are touched with the semi-crystalline object adhered to the inner furnace wall, the crystal production is failed midway, and normal production work and economic benefits are seriously affected.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a sintering hearth for synthesizing a crystal by a flame fusion method, and aims to solve the problem that a trapezoidal crystal growth space is not beneficial to the lateral growth of the crystal in the prior art.

In order to solve the technical problems, the technical scheme adopted by the utility model is as follows:

a sintering hearth for synthesizing crystals by a flame fusion method comprises a hearth shell, a heat-insulating layer and an inner furnace wall which are sequentially arranged from outside to inside, wherein a crystal growth space inside the inner furnace wall is of a spindle type with two thin ends and a thick middle part, and the maximum diameter of the crystal growth space is the growth length of the crystals.

As a further technical scheme of the above scheme, the sintering hearth further comprises a mandrel mold; the outline of the core rod die is the same as the outline of the internal crystal growth space of the inner furnace wall.

As a further technical scheme of the scheme, the core rod die and the inner furnace wall are of split structures.

As a further technical solution of the above solution, the mandrel mold includes an upper segment mandrel mold and a lower segment mandrel mold detachably connected to each other; the diameter of the joint of the upper section core rod die and the lower section core rod die is the maximum diameter of the core rod die.

As a further technical solution of the above solution, the inner furnace wall includes an upper section inner furnace wall and a lower section inner furnace wall detachably connected to each other; the diameter of the joint of the upper section inner furnace wall and the lower section inner furnace wall is the maximum diameter of the crystal growing space in the inner furnace wall.

As a further technical scheme of the scheme, the heat insulation layer is arranged in the middle of a crack space between the hearth shell and the inner furnace wall, and a supporting heat insulation layer is respectively arranged at the upper part and the lower part of the crack space. As a further technical solution to the above-mentioned solution,

the supporting heat-insulating layer is made of corundum sand or mixed corundum sand added with adhesive.

In summary, compared with the prior art, the utility model has the following advantages and beneficial effects: according to the utility model, the crystal growth space in the inner furnace wall is improved into a spindle-shaped curve structure, and the growth position of the crystal is located at the maximum diameter position of the crystal growth space, so that the crystal has enough growth space during transverse growth and can not touch the inner wall of the inner furnace wall any more, and the crystal can be completely grown in the transverse direction.

Drawings

FIG. 1 is a sintering furnace used for growing crystals by a conventional flame fusion method.

FIG. 2 is a schematic structural diagram of a sintering furnace chamber for synthesizing crystals by a flame fusion method according to the present invention

The explanation of each reference number in the figure is: the furnace comprises a hearth shell 1, an insulating layer 2, an inner furnace wall 3, an upper section inner furnace wall 31, a lower section inner furnace wall 32, a core rod mold 4, an upper section core rod mold 41, a lower section core rod mold 42 and a supporting and heat-insulating layer 5.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the present invention will be further described in detail with reference to the following embodiments.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. The terms first, second and the like, if any, are used for distinguishing technical features only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

As shown in figure 1, the sintering hearth used for crystal growth by the traditional flame melting method has the advantages that the trapezoidal core rod die is in the shape of a truncated cone, so that the inner crystal growth space of the punched inner furnace wall 3 is also in the shape of the truncated cone, the size change range of the inner crystal growth space from top to bottom is not large, the powder is in the shape of a sector during blanking, and a part of the powder scatters around the inner furnace wall 3 to be adhered to form a semi-crystalline object, so that the transverse growth of the crystal is influenced. The embodiment of the application improves the inside crystal growth space of the inner furnace wall 3 into the spindle-shaped curve structure with thinner middle parts at two ends, and the growth position of the crystal is located at the maximum diameter position of the crystal growth space, so that the crystal has enough growth space during transverse growth and can not touch the inner wall of the inner furnace wall 3, and the crystal can completely grow in the transverse direction.

As shown in fig. 2, the sintering furnace according to the embodiment of the present application includes a furnace shell 1, an insulating layer 2, and an inner furnace wall 3, an inner space of the inner furnace wall 3 is generally increased in size from top to bottom, an inner crystal growth space of the inner furnace wall 3 is a spindle-type curved structure, and a maximum diameter of the crystal growth space is a growth length of a crystal. Like the prior art, the furnace shell 1 in the embodiment of the application is made of seamless steel tubes, the heat-insulating layer 2 is made of heat-insulating cotton in a filling and compacting mode, and the inner furnace wall 3 is made of corundum sand. The crystal growth space in the inner furnace wall 3 is set to be of a spindle-shaped curve structure, and compared with a common cone frustum-shaped structure, the size change of the crystal growth space in the inner furnace wall is large from top to bottom, so that the entering of powder is not influenced, and the crystal has a large enough transverse growth space.

In order to successfully manufacture the inner furnace wall 3 with the spindle-shaped curve structure, the sintering hearth further comprises a core rod die 4, and the outline of the core rod die 4 is the same as the internal crystal growth space outline of the inner furnace wall 3. The inner crystal growth space which is completely the same as the outline of the core rod die 4 can be manufactured through the core rod die 4. However, since the outline of the core rod mold 4 is also of a spindle-type curve structure, the core rod mold can no longer be used for forging the inner furnace wall 3 as a whole as a common trapezoidal core rod mold in the prior art (unless a flexible core rod mold is used, the dimensional accuracy of the inner furnace wall 3 forged by the flexible core rod mold is not as good as that of the inner furnace wall 3 forged by a rigid core rod mold), because the middle diameter of the core rod mold 4 is larger than the diameters of the two ends, the inner furnace wall 3 can not be taken out after being forged. Therefore, in the embodiment of the application, the mandrel mould 4 and the inner furnace wall 3 are both of a split structure, and the inner furnace wall 3 is manufactured by a sectional manufacturing method, so that the problem of taking out the mandrel mould 4 can be well solved.

The embodiment of the application is improved and redesigned on the traditional mandrel mould to form the segmented mandrel mould 4 with the fusiform curve structure, the crystal growth space part of the mandrel mould 4 adopts a convex arc design, the transverse growth space of the crystal is increased, and the semi-crystalline object formed by powder material drifting and the contact of the powder material and the inner furnace wall 3 is reduced, so that the situation that the crystal is cracked due to the contact with the semi-crystalline object during transverse growth is avoided, and the crystal cannot fail in the production process is ensured. In order to manufacture the inner furnace wall 3 with the spindle-shaped curve structure, the core rod die 4 and the inner furnace wall 3 are both arranged into sectional structures, so that the inner furnace wall 3 can be manufactured conveniently, and when the inner furnace wall 3 is damaged or the heat preservation performance is reduced, only the inner furnace wall 3 where the corresponding section is located needs to be manufactured and replaced, and the inner furnace wall 3 does not need to be integrally damaged and manufactured again when the inner furnace wall 3 is replaced like the integral inner furnace wall 3 manufactured by the traditional trapezoidal core rod die. The embodiment of the application adopts a sectional type forging method to improve the use efficiency of the inner furnace wall 3 and reduce the cost of the original auxiliary materials.

In the embodiment of the present application, the mandrel mold 4 includes an upper segment mandrel mold 41 and a lower segment mandrel mold 42 detachably connected to each other; the diameter of the joint of the upper segment mandrel die 41 and the lower segment mandrel die 42 is the maximum diameter of the mandrel die 4. Correspondingly, the inner furnace wall 3 comprises an upper inner furnace wall 31 and a lower inner furnace wall 32, which are detachably connected to each other; the diameter of the joint of the upper inner furnace wall 31 and the lower inner furnace wall 32 is the maximum diameter of the crystal growth space in the inner furnace wall 3. The upper-section core rod die 41 and the lower-section core rod die 42, and the upper-section inner furnace wall 31 and the lower-section inner furnace wall 32 can be detachably connected by clamping, bonding, threaded connection, embedding, sealing and combining and the like so as to ensure the heat insulation performance of the furnace.

The method for manufacturing the inner furnace wall 3 in the embodiment of the application is slightly different from the traditional method, and the manufacturing method comprises the following steps:

the first step is as follows: the upper-section mandrel mould 41 is vertically fixed at the axle center of a section of seamless steel pipe, then the position of the upper-section mandrel mould 41 is locked, so that the position of the upper-section mandrel mould 41 is not deviated, and the maximum diameter position of the upper-section mandrel mould 41 is spaced from the inner wall of the seamless steel pipe by a certain distance (usually 5cm), so that a spacing space is formed. Then, mixed corundum sand with adhesive is added into the interval space, and the mixed corundum sand is compacted by gravity. And then the whole is put into a baking oven to be baked, and then the upper section mandrel mould 41 and the hard upper section inner furnace wall 31 are taken out of the seamless steel tube, wherein the taking-out directions of the upper section mandrel mould 41 and the upper section inner furnace wall 31 are opposite, namely one is taken out downwards and the other is taken out upwards. The lower inner furnace wall 32 is then stamped with the lower core rod die 42 in the same manner.

The second step is that: the manufactured upper section inner furnace wall 31 and the lower section inner furnace wall 32 are vertically placed at the axle center of another section of seamless steel pipe (the seamless steel pipe is the furnace shell 1, and the diameter of the furnace shell 1 is larger than that of the seamless steel pipe in the first step), the combination position between the upper section inner furnace wall 31 and the lower section inner furnace wall 32 is adjusted, and the combination is ensured to be closed and fixed without shaking. Encircle again between furnace shell 1 and interior oven 3 and arrange the heat preservation cotton and the compaction forms heat preservation 2, in the embodiment of this application, the height of heat preservation 2 is about 2/3 of the crack space height between furnace shell 1 and the interior oven 3, and heat preservation 2 mainly covers in the middle part of interior oven 3, ensures that the inside crystal growth space of interior oven 3 is whole to be covered by heat preservation 2, can have stable environment during crystal growth. And the rest 1/3 of the crack space between the hearth shell 1 and the inner furnace wall 3 is filled with corundum sand or mixed corundum sand with adhesive to form a supporting and heat-insulating layer 5, and the supporting and heat-insulating layer 5 is compacted by gravity, so that the whole sintering hearth is manufactured. This support insulating layer 5 can improve whole sintering furnace upper end and intensity of lower extreme when reducing the heat loss in interior oven 3 to avoid getting damaged inner structure when putting sintering furnace.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above preferred embodiments should not be considered as limiting the utility model, which is subject to the scope defined by the claims. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the spirit and scope of the utility model, and these modifications and adaptations should be considered within the scope of the utility model.

Claims

1. The utility model provides a sintering furnace that synthetic crystal of flame fusion method was used, includes furnace shell (1), heat preservation (2) and interior oven wall (3) that set gradually from outside to inside, its characterized in that: the inner crystal growth space of the inner furnace wall (3) is of a spindle type with two thin ends and a thick middle part, and the maximum diameter of the crystal growth space is the growth length of crystals.

2. A sintering furnace for synthesizing crystal by flame fusion method as claimed in claim 1, characterized in that: the sintering hearth further comprises a core rod die (4); the outline of the core rod die (4) is the same as the internal crystal growth space outline of the inner furnace wall (3).

3. A sintering furnace for synthesizing crystal by flame fusion method as claimed in claim 2, characterized in that: the core rod die (4) and the inner furnace wall (3) are both of split structures.

4. A sintering furnace for synthesizing crystal by flame fusion method as claimed in claim 3, characterized in that: the mandrel mould (4) comprises an upper segment mandrel mould (41) and a lower segment mandrel mould (42) which are detachably connected with each other; the diameter of the joint of the upper section core rod die (41) and the lower section core rod die (42) is the maximum diameter of the core rod die (4).

5. A sintering furnace for synthesizing crystal by flame fusion method as claimed in claim 3, characterized in that: the inner furnace wall (3) comprises an upper section inner furnace wall (31) and a lower section inner furnace wall (32) which are detachably connected with each other; the diameter of the joint of the upper section inner furnace wall (31) and the lower section inner furnace wall (32) is the maximum diameter of the crystal growth space in the inner furnace wall (3).

6. A sintering furnace for synthesizing crystal by flame fusion method as claimed in claim 1, characterized in that: the heat-insulating layer (2) is arranged in the middle of a crack space between the hearth shell (1) and the inner furnace wall (3), and a supporting heat-insulating layer (5) is respectively arranged at the upper part and the lower part of the crack space.

7. A sintering furnace for synthesizing crystal by flame fusion method as claimed in claim 6, characterized in that: the supporting and heat-insulating layer (5) is corundum sand or mixed corundum sand added with adhesive.