Rotary kiln composite inner container for Bi-series superconducting powder

Abstract

The invention discloses a rotary kiln composite liner for Bi-series superconducting powder, the composite liner comprises a cylindrical main body, the cylindrical main body comprises an inner barrier silver liner and an outer support stainless steel liner from inside to outside in sequence, the barrier silver liner is further provided with a plurality of triangular support silver shifting plates which are uniformly distributed, and the triangular support silver shifting plates are connected with the inner barrier silver liner and the outer support stainless steel liner. The two ends of the cylindrical body are each provided with a conical barrel with an opening. According to the invention, the inner-layer barrier silver liner does not react with the Bi-series superconducting powder when the Bi-series superconducting powder is heated, contact with other materials is avoided, adverse effects on the Bi-series superconducting powder in the sintering process are avoided, and the outer-layer support stainless steel liner is arranged outside the inner-layer barrier silver liner to support the inner-layer barrier silver liner, so that the reliability of the Bi-series superconducting powder is improved. The problem that the inner container is clamped in a rotary kiln and cannot be taken out due to deformation of the inner-layer blocking silver container in the high-temperature sintering process is solved, meanwhile, the structural strength of the composite inner container is improved, long-time sintering of high-purity Bi-series superconducting powder is achieved, and the service life of the composite inner container is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of Bi-based high-temperature superconducting wire strips, and in particular relates to a composite inner liner of a rotary kiln for Bi-based superconducting powders. Background Art

[0002] Bi-based high-temperature superconducting wires have shown great potential in applications such as magnetic confinement fusion, superconducting cables, superconducting transformers, and superconducting fault current limiters. As the core raw material for Bi-based superconducting wires and strips, the quality of the precursor powder is crucial, and its uniformity is the key indicator for measuring powder quality, which is directly related to the current-carrying performance and overall performance of the superconducting wires and strips.

[0003] In the prior art, Bi-based superconducting powders are processed in a rotary furnace, thereby achieving high uniformity and large-scale sintering of Bi-based precursor powders. However, since pure oxygen atmosphere is used in the sintering process of Bi-based superconducting powders, and a 310S inner shell is used in conventional rotary furnaces, the inner shell will be partially oxidized during the sintering process to form powder that will separate from the inner shell and enter the sintered Bi-based superconducting powder, thereby causing the impurity content in the powder to gradually increase, which affects the performance of the Bi-based superconducting powder.

[0004] Therefore, a composite liner of a rotary kiln for Bi-based superconducting powder is needed. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a composite inner liner for a rotary kiln for Bi-based superconducting powder in view of the deficiencies of the above-mentioned prior art. The composite inner liner will not react with the Bi-based superconducting powder when the Bi-based superconducting powder is heated by setting an inner layer of barrier silver liner, thereby avoiding adverse effects on the Bi-based superconducting powder during the sintering process. In addition, an outer layer of supporting stainless steel liner is set outside the inner layer of barrier silver liner to support the inner layer of barrier silver liner, thereby avoiding the problem that the inner liner is stuck in the rotary kiln and cannot be taken out due to deformation of the inner layer of barrier silver liner during high-temperature sintering, and at the same time, the structural strength of the composite inner liner is also improved.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a composite inner liner for a rotary kiln for Bi-based superconducting powder, characterized in that the composite inner liner includes a cylindrical main body, and the cylindrical main body is composed of an inner barrier silver liner and an outer support stainless steel liner from the inside to the outside, and a plurality of evenly distributed triangular supporting silver stripping plates are also arranged on the barrier silver liner, and open conical cylinders are installed at both ends of the cylindrical main body.

[0007] The above-mentioned composite inner liner of a rotary kiln for Bi-based superconducting powder is characterized in that the inner layer barrier silver liner is made of a silver plate with a thickness of not less than 4 mm and a mass fraction greater than 99.9%.

[0008] The above-mentioned composite inner liner of a rotary kiln for Bi-based superconducting powder is characterized in that the outer supporting stainless steel liner is made of 310S stainless steel with a thickness of not less than 5 mm.

[0009] The above-mentioned composite liner of a rotary kiln for Bi-based superconducting powder is characterized in that the triangular supporting silver shifting plate is welded into an equilateral triangle structure using a silver plate with a thickness of not less than 4 mm, and the height of the equilateral triangle structure is not less than 1 / 5 of the diameter of the inner layer barrier silver liner.

[0010] The above-mentioned composite inner liner of a rotary kiln for Bi-based superconducting powder is characterized in that the number of the triangular supporting silver material-shifting plates is 3 or 4.

[0011] The above-mentioned composite liner of a rotary kiln for Bi-based superconducting powder is characterized in that the top angle and bottom angle of the open conical tube are both 45°, and the opening diameter is 1 / 3 of the inner diameter of the inner barrier silver liner.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. The present invention provides an inner barrier silver liner so that the inner barrier silver liner will not react with the Bi-based superconducting powder when the Bi-based superconducting powder is heated, thereby avoiding contact between the Bi-based superconducting powder and other materials and avoiding adverse effects on the Bi-based superconducting powder during the sintering process. In addition, an outer support stainless steel liner is provided outside the inner barrier silver liner to support the inner barrier silver liner, thereby avoiding the problem that the inner liner is stuck in the rotary kiln and cannot be taken out due to deformation of the inner barrier silver liner during high-temperature sintering. At the same time, the structural strength of the composite liner is also improved, thereby achieving long-term sintering of high-purity Bi-based superconducting powder and improving the service life of the composite liner.

[0014] 2. The composite liner of the present invention has a simple structure and only requires simple assembly. It is possible to realize a composite liner that meets the requirements of the rotational sintering of Bi-based superconducting powder without explosive composite welding and riveting, thereby greatly reducing the production cost.

[0015] 3. The present invention provides a plurality of evenly distributed triangular supporting silver stripping plates to stir the Bi-based superconducting powder inside the composite liner during the rotation of the composite liner, thereby ensuring that the Bi-based superconducting powder is heated evenly. The triangular supporting silver stripping plates with a triangular structure have better stability, avoiding serious deformation caused by excessive force on the root of the silver stripping plates, thereby increasing the service life of the composite liner.

[0016] 4. The present invention adopts a silver plate with a thickness of not less than 4 mm to be welded into an equilateral triangle structure to form a triangular support silver prying plate, thereby ensuring the structural strength of the triangular support silver prying plate, avoiding serious deformation caused by excessive force on the root of the triangular support silver prying plate when stirring Bi-based superconducting powder, and improving the service life of the composite liner. The triangular design effectively prevents the silver prying plate from softening at high temperature, and the hollow triangular support silver prying plate structure reduces the amount of silver and the overall weight, thereby reducing the cost.

[0017] 5. The present invention controls the height of the equilateral triangle structure, that is, controls the height of the triangular supporting silver stripper plate, thereby ensuring sufficient stirring of the Bi-based superconducting powder during the rotation of the composite inner liner and ensuring the heating uniformity of the Bi-based superconducting powder.

[0018] 6. The design of the composite inner liner of the rotary kiln for Bi-based superconducting powder of the present invention fully considers the actual production needs. It has a simple structure, convenient operation, and is easy to integrate with the existing production line. It provides strong technical support for the industrial production of sintering of Bi-based superconducting powder and realizes the preparation of Bi-based superconducting powder. It has the significant advantages of simple structure, easy industrial application, and low production cost.

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the composite inner liner of the rotary kiln for Bi-based superconducting powder of the present invention.

[0021] Figure 2 for Figure 1 AA section view.

[0022] Description of reference numerals:

[0023] 1—Inner layer barrier silver liner; 2—Outer layer support stainless steel liner; 3—Triangular support silver stripping plate;

[0024] 4—Conical cylinder. DETAILED DESCRIPTION

[0025] The composite inner liner of a rotary kiln for Bi-based superconducting powder of the present invention is described in detail through Example 1.

[0026] Example 1

[0027] like Figure 1 and Figure 2As shown, in this embodiment, a composite inner liner of a rotary kiln for Bi-based superconducting powder includes a cylindrical body, and the cylindrical body is composed of an inner barrier silver liner 1 and an outer support stainless steel liner 2 from the inside to the outside. The barrier silver liner is also provided with a plurality of evenly distributed triangular supporting silver stripping plates 3, and both ends of the cylindrical body are installed with open conical cylinders 4.

[0028] It should be noted that, by setting a cylindrical main body, the main structure of the composite liner of the rotary kiln is constituted, and by setting an inner barrier silver liner 1 and an outer support stainless steel liner 2 respectively, the inner barrier silver liner 1 will not be oxidized when the Bi-based superconducting powder is heated, will not react with the Bi-based superconducting powder, and will not affect the Bi-based superconducting powder during the heating process. At the same time, it avoids the contact between the Bi-based superconducting powder and other materials, and avoids the adverse effects on the Bi-based superconducting powder during the sintering process. In addition, an outer support stainless steel liner 2 is arranged outside the inner barrier silver liner 1 to support the inner barrier silver liner 1, so as to avoid the problem that the liner is stuck in the rotary kiln and cannot be removed due to deformation of the inner barrier silver liner 1 during high-temperature sintering. At the same time, it also improves the structural strength of the composite liner and improves the service life of the composite liner.

[0029] It should be noted that by arranging a plurality of evenly distributed triangularly supported silver feed plates 3, the Bi-based superconducting powder inside the composite liner is stirred during the rotation of the composite liner, thereby ensuring that the Bi-based superconducting powder is heated evenly. In addition, the triangularly supported silver feed plates 3 with a triangular structure have better stability, avoiding serious deformation caused by excessive force on the root of the silver feed plates, thereby increasing the service life of the composite liner.

[0030] It should be noted that, by providing an open conical cylinder 4, the Bi-based superconducting powder is kept in the area of ​​the composite inner liner during the rotation of the composite inner liner, which improves the uniformity of heating and prevents the Bi-based superconducting powder from leaking out and contaminating the rotary kiln. It also facilitates the complete pouring out of the Bi-based superconducting powder after heat treatment to avoid the residue of Bi-based superconducting powder.

[0031] It should be noted that when the composite inner liner of a rotary kiln for Bi-based superconducting powder of this embodiment is actually used, the Bi-based superconducting powder is added into the inner barrier silver liner 1 of the composite inner liner through the open conical tube 4, and then the composite inner liner is placed in a rotary kiln for heating and rotating operations, so that the Bi-based superconducting powder is sintered and rotated and stirred inside the inner barrier silver liner 1, effectively avoiding the contamination of the Bi-based superconducting powder by conventional metals, and at the same time avoiding the problem of the inner liner getting stuck due to deformation of silver during high-temperature sintering.

[0032] In this embodiment, the inner barrier silver liner 1 is made of a silver plate with a thickness of not less than 4 mm and a mass fraction greater than 99.9%. The thickness of the inner barrier silver liner 1 is controlled by controlling the thickness of the silver plate, so that the inner barrier silver liner 1 has a certain structural strength, and the mass fraction of the silver plate is controlled to prevent the introduction of impurities.

[0033] In this embodiment, the outer layer supporting stainless steel liner 2 is made of 310S stainless steel with a thickness of not less than 5mm. By using 310S stainless steel, it has the characteristics of heat resistance and oxidation resistance, and by controlling the thickness of 310S stainless steel to control the wall thickness of the outer layer supporting stainless steel liner 2, the outer layer supporting stainless steel liner 2 has a certain structural strength, and will not deform even if heated continuously at high temperature. At the same time, even if the inner layer barrier silver liner 1 is deformed, it will not affect the outer layer supporting stainless steel, avoiding the problem that the inner liner is stuck in the rotary kiln and cannot be taken out due to the deformation of the inner layer barrier silver liner 1 during high temperature sintering.

[0034] like Figure 2 As shown, in this embodiment, the triangular supporting silver-pickling plate 3 is welded into an equilateral triangle structure using a silver plate with a thickness of not less than 4 mm, and the height of the equilateral triangle structure is not less than 1 / 5 of the diameter of the inner layer blocking silver gallbladder 1. By using a silver plate with a thickness of not less than 4 mm to weld into an equilateral triangle structure to make a triangular supporting silver-pickling plate 3, the structural strength of the triangular supporting silver-pickling plate 3 is ensured, and the serious deformation caused by excessive force at the root of the triangular supporting silver-pickling plate 3 when stirring the Bi-based superconducting powder is avoided, and the service life of the composite liner is improved. The triangular design effectively prevents the silver-pickling plate from softening at high temperature, and the hollow triangular supporting silver-pickling plate 3 structure is used to reduce the amount of silver and the overall weight, thereby reducing the cost. By controlling the height of the equilateral triangle structure, that is, controlling the height of the triangular supporting silver-pickling plate 3, the Bi-based superconducting powder is fully stirred during the rotation of the composite liner, and the heating uniformity of the Bi-based superconducting powder is ensured.

[0035] In this embodiment, the number of the triangular supporting silver stripper plates 3 is 3 or 4. By controlling the number of the triangular supporting silver stripper plates 3, sufficient stirring of the Bi-based superconducting powder during the rotation of the composite inner container is ensured, and the heating uniformity of the Bi-based superconducting powder is ensured.

[0036] In this embodiment, the top and bottom angles of the open conical cylinder 4 are both 45°, and the opening diameter is 1 / 3 of the inner diameter of the inner barrier silver liner 1. By controlling the parameters of the open conical cylinder 4, the Bi-based superconducting powder is always in the area of ​​the composite liner during the rotation of the composite liner, which improves the uniformity of heating while preventing the Bi-based superconducting powder from leaking out and contaminating the rotary kiln, and also facilitates the complete pouring of the Bi-based superconducting powder after heat treatment to avoid the residue of Bi-based superconducting powder.

[0037] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent change made to the above embodiment according to the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A composite liner for a rotary kiln for Bi-based superconducting powder, characterized in that: The composite liner comprises a cylindrical body, wherein the cylindrical body comprises, from the inside to the outside, an inner layer barrier silver liner (1) and an outer layer support stainless steel liner (2), the barrier silver liner is also provided with a plurality of evenly distributed triangular support silver material-dispensing plates (3), and both ends of the cylindrical body are provided with open conical cylinders (4).

2. The composite inner liner of a rotary kiln for Bi-based superconducting powder according to claim 1, characterized in that: The inner layer of silver barrier (1) is made of a silver plate with a thickness of not less than 4 mm and a mass fraction greater than 99.9%.

3. The composite inner liner of a rotary kiln for Bi-based superconducting powder according to claim 1, characterized in that: The outer supporting stainless steel liner (2) is made of 310S stainless steel with a thickness of not less than 5 mm.

4. The composite inner liner of a rotary kiln for Bi-based superconducting powder according to claim 1, characterized in that: The triangular supporting silver stripping plate (3) is welded into an equilateral triangle structure using silver plates with a thickness of not less than 4 mm, and the height of the equilateral triangle structure is not less than 1 / 5 of the diameter of the inner layer barrier silver gallbladder (1).

5. The composite inner liner of a rotary kiln for Bi-based superconducting powder according to claim 1, characterized in that: The number of the triangular supporting silver material-shifting plates (3) is 3 or 4.

6. The composite inner liner of a rotary kiln for Bi-based superconducting powder according to claim 1, characterized in that: The top angle and bottom angle of the open conical tube (4) are both 45°, and the opening diameter is 1 / 3 of the inner diameter of the inner layer barrier silver gallbladder (1).

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