A tool for preparing a rotating tube and a rotating tube

Abstract

The present invention relates to the technical field of glass production equipment, and in particular to a tool and a rotating tube for preparing a rotating tube, so as to solve the problem of millimeter-level pores existing in the original position of the bearing member after the porous sponge body is limited in the prior art, and the technical problem of stress concentration in the circumferential direction. The tool includes a central axis, and a plurality of annular bearing members arranged around the central axis; the annular bearing member includes an upper ring and a lower ring, and an annular bearing space for bearing the porous sponge body is formed between the upper ring and the lower ring around the central axis. This solution can not only effectively bridge large pores but also improve thermal shock resistance.

Description

Technical Field

[0001] The invention relates to the technical field of glass production equipment, in particular to a tool for preparing a rotating tube and a rotating tube. Background Art

[0002] A rotating tube is required in the glass drawing process. A Chinese patent with application number CN202310569554.2 discloses a 3D printed porous medium burn-out hole-forming rotating tube preparation process and mold. The rotating tube is prepared by the porous medium burn-out hole-forming method, and a special mold is used to cooperate with the firing of the rotating tube, which improves the thermal shock resistance and significantly reduces the weight.

[0003] However, the above method uses a support to limit the porous sponge body, thereby effectively controlling the position of the porous sponge body. However, after the support is burned out, millimeter-level pores exist in the original position of the support, which are prone to stress concentration, leading to crack expansion and poor thermal shock resistance.

[0004] In addition, research has found that since the rotating tube in application number CN202310569554.2 uses a strip-shaped porous sponge, after the sponge is burned out, multiple spaced strip-shaped porous areas will be formed around the axial direction, and the porous areas are discontinuous, which leads to a very uneven pore distribution in the circumferential direction. The problem caused by the extremely uneven pore distribution in the circumferential direction is local thermal stress concentration, while the rotating tube requires uniform thermal stress distribution in the circumferential direction to ensure thermal shock performance. Summary of the invention

[0005] The present invention provides a pore-compensating rotating tube and a preparation method thereof, so as to solve the problem of millimeter-level pores existing in the original position of the bearing member after limiting the porous sponge body in the prior art, and the technical problem of stress concentration in the circumferential direction.

[0006] In order to alleviate the above technical problems, the technical solution provided by the present invention is:

[0007] A tool for preparing a rotating tube,

[0008] It includes a central axis and a plurality of annular bearing members arranged around the central axis;

[0009] The annular bearing member comprises an upper ring and a lower ring, and an annular bearing space for bearing the porous sponge body is formed between the upper ring and the lower ring around the central axis.

[0010] Furthermore,

[0011] The annular carrier is made of an organic material and disappears after the first sintering.

[0012] Furthermore,

[0013] Also includes a cover body, the cover body is connected to the end of the central shaft;

[0014] Furthermore,

[0015] One end of the mold shell is open, and the cover body is adapted to the opening.

[0016] A rotating tube is prepared by using the above tool.

[0017] Furthermore,

[0018] The rotating tube is made of the following raw materials in parts by weight:

[0019] 50-70 parts of high-purity sintered mullite;

[0020] 8-20 parts of talc;

[0021] 7-15 parts of aluminum oxide powder;

[0022] 4-10 parts of silica powder;

[0023] 3 to 25 parts of binding clay.

[0024] Furthermore,

[0025] The modified expanded graphite is prepared by the following method:

[0026] 1) preparing modified expanded graphite slurry: dissolving borax, barium nitrate and expanded graphite in deionized water, stirring and filtering, and then sintering in a helium atmosphere, grinding into powder after sintering, and then dissolving the modified expanded graphite in water to form modified expanded graphite slurry;

[0027] 2) soaking the porous sponge in modified expanded graphite slurry, and then drying the porous sponge containing the modified expanded graphite slurry in the shade;

[0028] 3) placing the air-dried porous sponge containing the modified expanded graphite slurry into a mold, injecting the rotating tube slurry, and demoulding after air-drying to form a semi-finished product;

[0029] 4) The first sintering is performed until the porous sponge is completely decomposed.

[0030] 5) After the first sintering is completed, the second sintering is carried out until the large gaps in the rotating tube are healed.

[0031] The pore compensation rotating tube is characterized by:

[0032] The weight ratio of borax, barium nitrate and expanded graphite is 2:5:30.

[0033] Furthermore,

[0034] The first sintering temperature is 1200-1500 degrees Celsius.

[0035] Furthermore,

[0036] The second sintering temperature is 800-1000 degrees Celsius.

[0037] The effect analysis is as follows:

[0038] Expanded graphite is a carbonaceous raw material made by chemical or electrochemical intercalation of natural flake graphite, and then instantaneously heating it to produce high-temperature expansion. Expanded graphite has a well-developed pore structure, but it is prone to collapse and agglomeration.

[0039] This solution uses a special tool to prepare a rotating tube, which includes: a central axis and a plurality of annular bearing members arranged around the central axis; the annular bearing members include an upper ring and a lower ring, and an annular bearing space for bearing a porous sponge body is formed between the upper ring and the lower ring around the central axis.

[0040] Therefore, after the rotary tube is formed, an annular skeleton will be formed in the circumferential direction. The annular skeleton can not only reduce weight, but also ensure uniform pore distribution in the circumferential direction to avoid local stress concentration.

[0041] In addition, the modified expanded graphite is added to the rotating tube slurry in this scheme. The modified expanded graphite is prepared by borax, barium nitrate and expanded graphite. First, borax provides B atoms, B 2 O 3 As a network-forming entity, it itself has [BO 3 ]、[BO 4 ] Two coordination forms, when there is sufficient free oxygen in the network, B 2 O 3 Will form [BO 4 ] unit; when free oxygen is insufficient, [BO 3 ] unit. Barium nitrate (Ba(NO 3 ) 2 ) decomposes into barium oxide (BaO), nitrogen dioxide (NO 2 ) and oxygen (O 2 ), which can provide a large amount of free oxygen, and the presence of free oxygen will accelerate [BO 3 ]Unit body direction [BO 4 ]Unit transformation, [BO 4 ] and [SiO 4 ] is a stable network structure. A large amount of [BO 4The network structure can effectively support the expanded graphite and prevent the expanded graphite from collapsing and agglomerating, which means that it can better ensure the pore stability inside the rotating tube system. The stable pore structure helps to improve the thermal shock resistance.

[0042] Secondly, [BO 3 ]Unit body direction [BO 4 ] The unit body is transformed, and the transformation process is accompanied by volume expansion. Therefore, it can effectively bridge the large pores formed after the carrier is burned out. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic diagram of the structure of a tool provided in an embodiment of the present invention.

[0044] 100-central axis; 200-carrying member; 210-upper ring; 220-lower ring; 300-porous sponge body; 400-cover body. DETAILED DESCRIPTION

[0045] Example 1

[0046] This embodiment provides a method for preparing a rotating tube, comprising the following steps:

[0047] 1) preparing a modified expanded graphite slurry: dissolving borax, barium nitrate and expanded graphite in deionized water in a weight ratio of 2:5:30, stirring and filtering, and then sintering in a helium atmosphere, grinding into powder after sintering, and then dissolving the modified expanded graphite in water to form a modified expanded graphite slurry;

[0048] 2) soaking the porous sponge in modified expanded graphite slurry, and then drying the porous sponge containing the modified expanded graphite slurry in the shade;

[0049] 3) placing the air-dried porous sponge containing the modified expanded graphite slurry into a mold, injecting the rotating tube slurry, and demoulding after air-drying to form a semi-finished product;

[0050] 4) First sintering until the porous sponge is completely decomposed;

[0051] 5) After the first sintering is completed, the second sintering is carried out until the large gaps in the rotating tube are healed.

[0052] The rotary tube slurry is made from the following raw materials in parts by weight:

[0053] 50-70 parts of high-purity sintered mullite;

[0054] 8-20 parts of talc;

[0055] 7-15 parts of aluminum oxide powder;

[0056] 4-10 parts of silica powder;

[0057] 3 to 25 parts of binding clay.

[0058] The rotating tube in this embodiment is made by the following tools: Figure 1 As shown, the tool includes a central axis 100, and a plurality of annular bearing members 200 arranged around the central axis 100; the annular bearing member 200 includes an upper ring 210 and a lower ring 220, and an annular bearing space for bearing a porous sponge 300 is formed between the upper ring 210 and the lower ring 220 around the central axis 100. The annular bearing member 200 is made of organic material, and the annular bearing member 200 disappears after the first sintering. It also includes a cover 400, which is connected to the end of the central axis 100; one end of the mold shell is open, and the cover 400 is adapted to the opening.

[0059] By observing the cross section of the sample perpendicular to the axial direction, it was found that the pores at the position corresponding to the porous sponge were evenly distributed, and the pore area of ​​the porous sponge around the axial direction was evenly distributed.

[0060] The samples were tested for thermal shock resistance, and the rotating tube prepared by the above process could withstand 45 thermal shock cycles.

[0061] Comparative Example 1

[0062] The raw material ratio of the modified expanded graphite and the ratio of the rotating tube slurry in this comparative example are the same as those in Example 1. Compared with Example 1, the structure of the carrier tool and the porous sponge in this comparative example is the same as that in CN202310569554.2.

[0063] The cross-section of the sample perpendicular to the axis direction was observed. The porous sponge area was offset on different slices, indicating that the porous sponge was offset during the immersion process. In addition, large pores (larger than 1 mm) were found on the slices corresponding to the carrier tool. The reason for the large pores was that the carrier tool was burned out.

[0064] The samples were tested for thermal shock resistance, and the rotating tube prepared by the above process could withstand 39 thermal shock cycles.

[0065] Comparative Example 2

[0066] The modified expanded graphite ratio in this comparative example is different from that in comparative example 1, specifically:

[0067] Borax: barium nitrate: expanded graphite = 7:0:30, and the rest are the same.

[0068] By observing the cross section of the sample, it was found that there were many large pores (larger than 1 mm) at the position corresponding to the porous sponge. The possible reason is that without the presence of barium nitrate, there is insufficient free oxygen in the system, [BO 4] The network structure is insufficient, so the system support capacity of expanded graphite is insufficient, and the expanded graphite collapses and agglomerates. The expanded graphite system is unstable, and large pores appear, which is not conducive to the transfer of thermal energy stability.

[0069] The samples were tested for thermal shock resistance, and the rotating tube prepared by the above process could withstand 29 thermal shock cycles.

[0070] Comparative Example 3

[0071] The modified expanded graphite ratio in this comparative example is different from that in comparative example 1, specifically:

[0072] Borax: barium nitrate: expanded graphite = 0:7:30, and the rest are the same.

[0073] Observation of the sample cross section revealed that a large number of large pores (greater than 1 mm) appeared at the location corresponding to the porous sponge. The possible reason is that without the presence of borax, there are no [BO3] units and [BO4] units in the system, so the system's support capacity for expanded graphite is insufficient, and the expanded graphite collapses and agglomerates.

[0074] The samples were tested for thermal shock resistance, and the rotating tube prepared by the above process can withstand 31 thermal shock cycles. The expanded graphite system is unstable and has large pores, which is not conducive to the transfer of thermal energy stability.

[0075] Comparative Example 4

[0076] The expanded graphite in this comparative example is not modified, and the rest is the same.

[0077] By observing the cross section of the sample, it was found that a large number of large pores (larger than 1 mm) appeared at the position corresponding to the porous sponge.

[0078] The samples were tested for thermal shock resistance, and the rotating tube prepared by the above process could withstand 32 thermal shock cycles.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tool for preparing a rotating tube, characterized in that: It includes a central axis and a plurality of annular bearing members arranged around the central axis; The annular bearing member comprises an upper ring and a lower ring, and an annular bearing space for bearing the porous sponge body is formed between the upper ring and the lower ring around the central axis.

2. The tool for preparing a rotating tube according to claim 1, characterized in that: The annular carrier is made of an organic material and disappears after the first sintering.

3. The tool for preparing a rotating tube according to claim 2, characterized in that: The utility model also comprises a cover body, wherein the cover body is connected to the end of the central shaft.

4. The tool for preparing a rotating tube according to claim 3, characterized in that: It also includes a mold shell, one end of which is open, and the cover body is adapted to the opening.

5. A rotating tube, characterized in that: The method is prepared by using the tool as described in any one of claims 1 to 4.

6. The rotating tube according to claim 5, characterized in that: The rotating tube is made of the following raw materials in parts by weight: 50-70 parts of high-purity sintered mullite; 8-20 parts of talc; 7-15 parts of aluminum oxide powder; 4-10 parts of silica powder; 3-25 parts of binding clay; 5 to 10 parts of modified expanded graphite.

7. The rotating tube according to claim 6, characterized in that: The modified expanded graphite is prepared by the following method: 1) preparing modified expanded graphite slurry: dissolving borax, barium nitrate and expanded graphite in deionized water, stirring and filtering, and then sintering in a helium atmosphere, grinding into powder after sintering, and then dissolving the modified expanded graphite in water to form modified expanded graphite slurry; 2) soaking the porous sponge in modified expanded graphite slurry, and then drying the porous sponge containing the modified expanded graphite slurry in the shade; 3) placing the air-dried porous sponge containing the modified expanded graphite slurry into a mold, injecting the rotating tube slurry, and demoulding after air-drying to form a semi-finished product; 4) First sintering until the porous sponge is completely decomposed; 5) After the first sintering is completed, the second sintering is carried out until the large gaps in the rotating tube are healed.

8. The rotating tube according to claim 7, characterized in that: The weight ratio of borax, barium nitrate and expanded graphite is 2:5:

30.

9. The rotating tube according to claim 7, characterized in that: The first sintering temperature is 1200-1500 degrees Celsius.

10. The rotating tube according to claim 7, characterized in that: The second sintering temperature is 800-1000 degrees Celsius.

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