Ceramic tube forming mold

Abstract

The application provides a ceramic pipe forming die, which comprises a first die and a second die arranged symmetrically, the cross section of the first die and the second die in the radial direction is in a half ring shape, and the first die and the second die are folded to form a complete ring forming die; the first die and the second die each comprise a flange section, a straight section and a plug section arranged in sequence along the axial direction; wherein the straight section is an integral forming structure, the length of the straight section is not less than 2500 mm, and the pipe body structure of the straight section is provided with dense and uniformly distributed filter through holes. The ceramic pipe forming die in the application sets the straight section as an integral forming structure, and the filter through holes are dense and uniformly distributed, so that the ceramic pipe can be uniformly distributed and layered consistently in the whole length direction, the quality defects at the welding seam of the existing spliced die are avoided, the forming quality of the ceramic filter pipe is effectively improved, and the performance requirements of the industrial waste gas treatment are better met.

Description

Technical Field

[0001] This invention relates to the field of environmental protection equipment technology, and in particular to a ceramic tube forming mold. Background Technology

[0002] With the rapid pace of industrialization, industrial waste gas emissions have become a major source of environmental pollution. The harmful substances contained in these emissions, such as nitrogen oxides, sulfur dioxide, and volatile organic compounds, not only severely damage air quality and threaten human health, but also trigger a series of environmental problems, including acid rain and photochemical smog. Ceramic filter tubes, as a highly efficient and durable filtration material, play a crucial role in industrial waste gas treatment. With their numerous advantages, including high temperature resistance, corrosion resistance, high strength, high filtration efficiency, and long service life, they are widely used in waste gas treatment processes across various industries, including chemical, power, metallurgy, and waste incineration. In chemical waste gas treatment, ceramic filter tubes can filter particulate matter and volatile metals from the waste gas, reducing environmental pollution. In waste incineration, they can efficiently remove pollutants such as dust and nitrogen oxides from flue gas, contributing to clean emissions.

[0003] In large-scale industrial waste gas treatment scenarios, extremely stringent requirements are placed on the performance and specifications of ceramic filter tubes. From a performance perspective, ceramic filter tubes need to possess excellent dust removal, denitrification, and denitrification functions to effectively handle the complex and diverse composition of industrial waste gases. In chemical waste gases, in addition to conventional dust particles, various organic compounds and heavy metal vapors may be present; in coal-fired waste gases from the power industry, sulfur dioxide, nitrogen oxides, and large amounts of fly ash are the main pollutants. Ceramic filter tubes must be able to operate stably in these complex environments, efficiently removing various pollutants and ensuring that waste gas emissions meet stringent environmental standards. From a specification perspective, to meet the treatment needs of large-scale industrial waste gases, ceramic filter tubes typically need to be quite long. In some large-scale industrial waste gas treatment systems, such as large thermal power plants and metallurgical plants, the waste gas volume is enormous, requiring ceramic filter tubes to have sufficient filtration area and treatment capacity. Research and practice show that ceramic filter tubes with a length of 2 meters or more can better adapt to the requirements of large-scale waste gas treatment. By increasing the filtration area, the contact time between the waste gas and the filter material can be extended, thereby achieving more efficient filtration and purification.

[0004] As a core factor determining the quality and performance of ceramic filter tubes, the design and manufacturing process of the mold are of paramount importance. A high-quality mold not only ensures the dimensional and shape accuracy of the ceramic filter tube but also influences its internal microstructure, thereby determining key indicators such as filtration performance, mechanical properties, and chemical stability. If the mold design is unreasonable or the manufacturing process is flawed, problems such as dimensional deviations, surface defects, and uneven internal structures will occur in the ceramic filter tube. These problems will significantly reduce the performance of the ceramic filter tube, making it unable to meet the stringent requirements of industrial waste gas treatment.

[0005] In the current manufacturing process of ceramic filter tubes, the forming mold mainly consists of an inner mold and an outer mold working together. The inner mold typically adopts a shaft-like structure, and its working principle is based on centrifugal feeding technology. When the inner mold rotates at high speed, the ceramic fiber raw material placed inside is evenly thrown towards the inner wall of the mold under the action of centrifugal force. This centrifugal force causes the ceramic fiber raw material to gradually accumulate and distribute evenly on the inner wall of the mold, laying the foundation for subsequent forming. The outer mold mainly undertakes the key task of vacuum extraction to assist in the forming of the ceramic filter tube. By processing dense filtration holes on the mold wall and connecting it to a vacuum device, a negative pressure environment can be formed inside the outer mold during the forming process. Under this negative pressure, moisture and excess gas in the ceramic fiber raw material are quickly extracted, thereby accelerating the forming process of the ceramic filter tube and also helping to adjust the internal pore structure of the ceramic filter tube.

[0006] For long ceramic filter tubes (over 2 meters in length) that need to meet the requirements of large-scale industrial waste gas treatment, the outer mold is usually manufactured using a splicing method. This method typically involves manufacturing the mold in two or three or more sections. During processing, each section of the mold needs to be precisely machined with dense filtration holes. The density and distribution of these filtration holes directly affect the filtration effect and the final quality of the ceramic filter tube. Maintaining negative pressure filtration during the molding process is a key step in ensuring the quality of the ceramic filter tube. By connecting the filtration holes of the outer mold to a vacuum device, a stable negative pressure field is formed inside the mold, allowing the ceramic fiber raw material to be further compacted and shaped under negative pressure after centrifugal distribution. This negative pressure filtration not only removes moisture and gas from the ceramic fiber raw material but also promotes a more compact packing of ceramic particles, thereby ensuring that the material layering uniformity and porosity gradient of the ceramic tube meet the requirements.

[0007] During the manufacturing process of modular external molds, welds are inevitably produced due to the need to assemble multiple mold sections. The material structure of these weld areas differs from the original material structure of the mold body. During welding, the high temperature causes changes in the microstructure of the metal near the weld, leading to increased material density. For external molds with densely packed filtration holes, this structural change significantly reduces the permeability of the filtration holes within a 5mm area around the weld. This is because the material density at the weld increases the resistance to gas flow through the filtration holes, preventing it from passing as smoothly as in normal mold areas, resulting in poor or even extremely poor permeability in this region.

[0008] Due to air permeability issues at the weld seams of the splicing mold, poor material distribution and delamination occur at the weld joints of the ceramic filter tube during the forming process. During the centrifugal material distribution stage, when the ceramic fiber raw material is thrown towards the inner wall of the mold under centrifugal force, the poor air permeability at the weld seams prevents timely and effective filtration, hindering the release of moisture and gas from the ceramic fiber raw material in this area. This results in a different accumulation pattern of the ceramic fiber raw material in this area compared to other normal areas, leading to uneven material distribution. In subsequent forming processes, the residual moisture and gas prevent the formation of a uniform material delamination structure, resulting in poor material delamination in the ceramic tube.

[0009] When air permeability issues are severe, they can lead to areas of non-delamination and breakage in ceramic tubes. During the molding process, because filtration at the weld seam is almost impossible, a large amount of moisture and gas remains in the ceramic fiber raw material, preventing the ceramic fiber raw material in that area from bonding tightly and forming effective structural strength. As the molding process progresses, under stress, areas of non-delamination and breakage easily occur at the weld joint. This breakage problem severely damages the overall structural integrity of the ceramic tube, making it unable to withstand the pressure, temperature changes, and gas erosion during industrial waste gas treatment, greatly reducing the service life and performance of the ceramic tube.

[0010] In summary, current spliced ​​external molds used for the fabrication of long ceramic filter tubes suffer from numerous problems that severely impact the quality of these tubes. The adverse effects of welds on the air permeability of the filtration holes, and the resulting issues with material distribution and delamination during the ceramic tube forming process, even leading to areas of non-delamination and breakage, make it difficult for the produced ceramic filter tubes to meet the stringent requirements of large-scale industrial waste gas treatment. These problems not only reduce the filtration performance of the ceramic filter tubes but also significantly shorten their service life, increasing the operating costs and maintenance difficulty of industrial waste gas treatment systems. In practical applications, malfunctions in waste gas treatment systems caused by ceramic filter tube quality issues not only result in economic losses but may also cause serious environmental pollution, contradicting the original purpose of industrial waste gas treatment. Therefore, developing a new type of ceramic filter tube forming mold that can effectively solve the above problems is urgently needed. Summary of the Invention

[0011] In view of this, embodiments of the present invention provide a ceramic tube forming mold to eliminate or improve one or more defects existing in the prior art.

[0012] The ceramic tube forming mold includes a first mold and a second mold arranged symmetrically. The cross-section of the first mold and the second mold in the radial direction is semi-circular. The first mold and the second mold are joined together to form a complete annular forming mold. The first mold and the second mold each include a flange section, a straight section and a plug section arranged sequentially along their axial direction. The straight section is an integrally formed structure with a length of not less than 2500 mm. The tube structure of the straight section is provided with densely and evenly distributed suction holes.

[0013] In some embodiments, the filtration through-hole is configured as a tapered hole, wherein the inner wall diameter of the tapered hole is larger than its outer wall diameter; or, the inner wall portion of the filtration through-hole has a chamfered structure.

[0014] In some embodiments, the first mold and the second mold include the tube structure and the docking structures disposed on both sides of the tube structure. The docking structures on both sides extend outward along the diameter direction at both ends of the semi-circular portion of the tube structure. The docking structures are continuously disposed or spaced apart along the length direction of the tube structure.

[0015] In some embodiments, the docking structure has a docking portion; the docking portion is configured as a plane, or the docking portions of the first mold and the second mold are mutually concave and convex.

[0016] In some embodiments, the first mold and the second mold further include a support base, which is disposed on the outer side of the tube structure and / or the docking structure and is fixedly connected to the tube structure and / or the docking structure.

[0017] In some embodiments, the support base includes support blocks respectively disposed below the docking portions on both sides, the support blocks being fixedly connected to the docking portions; a negative pressure filtration channel is provided between the support blocks and the tube structure; the support blocks are continuously or intermittently arranged along the length direction of the tube structure.

[0018] In some embodiments, the support base includes at least one support piece disposed below the tube structure, the top of the support piece having an arc-shaped support portion, the arc-shaped support portion being fixedly connected to the outer wall of the tube structure; in the circumferential direction of the tube structure, the arc-shaped support portion is configured as a continuous structure or an intermittent structure; when there are two or more support pieces, the support blocks are intermittently disposed in the length direction of the tube structure.

[0019] In some embodiments, the diameter of the filtration through-hole does not exceed 1 mm, and the edge distance between adjacent holes does not exceed 1 mm.

[0020] In some embodiments, in the first mold and the second mold, at least the lower mold has a straight segment in the middle that is separately configured from the flange segments and plug segments on both sides.

[0021] In some embodiments, the tube structure of the first mold and the second mold is made of 3 / 4H stainless steel.

[0022] In some embodiments, the thickness of the tube structure of the first mold and the second mold is 0.6 mm.

[0023] In some embodiments, the inner wall of the tube structure is formed with a smooth surface having a roughness of no more than 0.8 μm.

[0024] In this embodiment of the invention, the ceramic tube forming mold sets the straight section as an integral forming structure, and the filter holes are densely and evenly distributed, which can ensure that the ceramic tube is uniformly distributed and layered in the entire length direction, avoiding the quality defects that occur at the weld seam of the existing splicing mold, effectively improving the forming quality of the ceramic filter tube, and enabling it to better meet the performance requirements of industrial waste gas treatment.

[0025] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.

[0026] Those skilled in the art will understand that the objectives and advantages achievable with the present invention are not limited to those specifically described above, and that the above and other objectives achievable with the present invention will become clearer from the following detailed description. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. The components in the drawings are not drawn to scale but are merely illustrative of the principles of the invention. For ease of illustration and description of certain parts of the invention, corresponding portions in the drawings may be enlarged, i.e., may appear larger relative to other components in an exemplary device actually manufactured according to the invention.

[0028] Figure 1 This is an exploded view of a ceramic tube forming mold according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the structure of an existing ceramic tube.

[0030] Figure 3 This is a schematic diagram of the straight segment of a ceramic tube forming mold according to an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of the structure of a straight line segment from another perspective in one embodiment of the present invention.

[0032] Figure 5 This is a structural schematic diagram of the lower straight line segment from an upward viewing angle in one embodiment of the present invention.

[0033] Figure 6 yes Figure 5 A sectional view of plane AA, where plane AA is within the support piece.

[0034] Figure 7 yes Figure 5 A sectional view of the CC plane, where the CC section lies between the two support plates.

[0035] Figure 8 yes Figure 7 Enlarged view of part A in the image.

[0036] Reference numerals: a) First mold; b) Second mold;

[0037] 1. Flange section; 2. Straight section; 3. Plug section;

[0038] 21. Tube structure; 211. Filtering through-hole;

[0039] 22. Docking structure;

[0040] 23. Support base;

[0041] 231. Support block; 231-1. Negative pressure filtration channel;

[0042] 232, Support plate; 232-1, Arc-shaped support part. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0044] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0045] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0046] It should also be noted that, unless otherwise specified, the term "connection" in this article can refer not only to a direct connection, but also to an indirect connection involving an intermediary.

[0047] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0048] This invention provides a ceramic tube forming mold. It should be specifically noted that the ceramic tube forming mold described in this embodiment refers to an external mold for forming ceramic tubes (hereinafter also simply referred to as a mold). Figure 2 As shown, the open end of the ceramic tube is designed with an installation flange for top-down hoisting; the other end of the ceramic tube is a sealed end, which can be designed as a hemispherical structure. This sealed end can be designed as a solid structure or with a filter hole. In actual use, the outside of the ceramic tube contains the highly polluted flue gas to be treated. After passing through the tube wall structure, the highly polluted flue gas is treated into clean flue gas and discharged from the inside of the ceramic tube. This part is existing technology and will not be described in detail here.

[0049] like Figure 1 As shown, the ceramic tube forming mold includes a first mold a and a second mold b arranged symmetrically. The cross-section of the first mold a and the second mold b in the radial direction is semi-circular. The first mold a and the second mold b are joined together to form a complete ring forming mold, which is used for forming the outer contour of the ceramic tube.

[0050] Furthermore, the first mold a and the second mold b can have the same structure, both including a flange section 1, a straight section 2, and a plug section 3 arranged sequentially along their axial direction. The flange section 1 is located at one end of the straight section 2, such as... Figure 1 As shown on the left, its main function is to form the flange part of the ceramic tube. The plug section 3 is located at the other end of the straight section 2. It can close one end of the mold opening and together with the flange section 1, it forms a closed forming space. During the forming of the ceramic tube, the plug section 3 can prevent the ceramic slurry from overflowing from one end of the mold. In conjunction with the filtration operation on the straight section 2, it can ensure that the ceramic slurry is evenly distributed in the mold, thus ensuring the dimensional accuracy and structural integrity of the formed ceramic tube.

[0051] Furthermore, the straight segment 2 is a one-piece molded structure with a length of not less than 2500mm. This length design can fully meet the molding requirements of long ceramic filter tubes (such as those exceeding 2m in length) needed for large-scale industrial waste gas treatment. Optionally, by combining the flange segments 1 and plug segments 3 at both ends, the total mold length can reach 3m, manufacturing a 3m long ceramic tube, which can efficiently treat large-scale industrial waste gas.

[0052] Furthermore, the tube structure 21 of the straight segment 2 is provided with densely and evenly distributed suction filtration holes 211, which can be used as follows: Figure 8 As shown. These filtration through-holes 211 can achieve stable negative pressure filtration during the ceramic tube forming process, ensuring the uniformity of layering and porosity gradient of the ceramic tube material during forming, thereby effectively avoiding problems such as poor air permeability, uneven material distribution, and layering defects caused by welds in existing splicing molds.

[0053] During the ceramic tube forming process, the first mold a and the second mold b are first joined and fixed together through flange section 1 to form an annular mold cavity. The prepared ceramic slurry is injected into the inner mold (such as a centrifugal feeding shaft), and simultaneously, a filtration device is activated, applying negative pressure to the inside of the mold through the filtration through-holes 211 on the straight section 2. Under negative pressure, water in the ceramic slurry is extracted, and ceramic particles gradually deposit and form on the inner wall of the mold. Because the straight section 2 is integrally formed and the filtration through-holes 211 are densely and evenly distributed, it ensures uniform material distribution and consistent layering along the entire length of the ceramic tube, avoiding quality defects that occur at the weld seams of existing splicing molds. This effectively improves the forming quality of the ceramic filter tube, enabling it to better meet the performance requirements of industrial waste gas treatment.

[0054] In this embodiment of the invention, the straight section of the ceramic tube forming mold adopts an integrated structure, which can avoid the interference of the weld seam on the air permeability of the filtration hole, and ensure the formation of a uniform and stable negative pressure field during the negative pressure filtration process, thereby ensuring the uniformity of material distribution, material layering, and the rationality of porosity gradient of the ceramic filter tube during the forming process.

[0055] In some embodiments, such as Figure 1 As shown, the ceramic tube forming mold may also include a closed shell outside the first mold a and the second mold b. The closed shell can further enhance the sealing performance of the mold during vacuuming, prevent outside air from entering and affecting the negative pressure filtration effect, and ensure that the ceramic slurry is formed in a stable negative pressure environment; the closed shell provides a stable external support structure for the first mold a and the second mold b, and the mold can be fixedly installed with external equipment through the mounting holes and fasteners provided on the closed shell, ensuring the stability of the mold during use; in addition, the closed shell can also cooperate with a lifting mechanism to realize the lifting operation of the mold.

[0056] If the filter through-hole 211 adopts a conventional design with internal and external diameters, the fabric fiber cotton used to assist in the forming process of ceramic tubes is easily adsorbed into the hole. During the demolding process, the adsorbed fiber cotton will damage the surface structure of the ceramic tube, resulting in peeling during demolding, which seriously affects the appearance quality and forming qualification rate of the ceramic tube.

[0057] In some embodiments, such as Figure 8 As shown, the filtration through-hole 211 is configured as a conical hole, with the inner diameter of the conical hole being larger than its outer diameter; or, the inner wall of the filtration through-hole 211 has a chamfered structure. This invention designs the filtration through-hole 211 as a constricted conical hole with a large inner diameter and a small outer diameter, or sets a chamfered structure on the outer wall, effectively changing the internal structural morphology of the filtration through-hole 211. When the ceramic tube is demolded after molding, a separation interface with a narrow outer diameter and a wide inner diameter can be formed. Due to the inclination angle of the conical hole, the inner wall of the wet ceramic tube (the surface in contact with the mold) can naturally slide outward along the hole wall, avoiding the problems caused by the adsorption of fabric fibers into the hole and the pulling of the ceramic tube surface during demolding caused by through-holes or "small inner, large outer" conical holes. This significantly reduces demolding resistance, greatly improves demolding smoothness, effectively avoids the problem of peeling during demolding, and improves the molding quality and production efficiency of the ceramic tube.

[0058] Optionally, if the filtration through-hole 211 is set as a tapered hole, its taper can be set to 30-60°, such as 45°. This taper, combined with the smooth surface of the inner wall of the tube structure, can significantly reduce the contact area and friction between the ceramic tube and the hole wall. During the demolding process, the contact surface between the wet ceramic tube and the tapered hole naturally separates with the taper, which can effectively avoid the problems of fabric fiber adsorption and demolding peeling caused by the through-hole.

[0059] In this embodiment, the large inner wall pore diameter (e.g., 0.81 mm) increases the contact area between the ceramic slurry and the filtration through-hole 211, allowing water to quickly penetrate into the pores. The small outer wall pore diameter creates a throttling effect, preventing excessive negative pressure from causing localized excessive dehydration of the slurry and the formation of a dense layer. The 45° taper allows for a gradual flow of air within the pores, eliminating abrupt dead zones. Combined with the densely distributed through-hole layout, the filtration pressure difference along the entire length of the 3m long tube structure can be controlled within a set pressure range, ensuring a consistent porosity gradient along the length of the ceramic tube. This avoids localized pore blockage affecting gas flow and prevents excessively large pores from reducing filtration accuracy, thus meeting the dual requirements of high-efficiency filtration and low resistance in industrial waste gas treatment. Optionally, the filtration through-hole 211 in this embodiment can be processed using special methods, such as laser processing, electrical discharge machining, or electrolytic machining.

[0060] When processing such tiny tapered holes, laser processing utilizes a high-energy-density laser beam that can be precisely focused on the surface of the mold material, causing the material to melt, vaporize, and be removed instantly, thus achieving the processing of the tapered hole. During the processing, by precisely controlling parameters such as the output power of the laser beam, pulse width, spot size, and scanning path, the taper and diameter of the tapered hole can be accurately controlled.

[0061] Electrical discharge machining utilizes the principle of pulsed discharge corrosion. The tool electrode is made into a shape opposite to the target constricted tapered hole. In an insulating working fluid environment, a high-frequency pulse voltage is applied between the tool electrode and the mold workpiece to generate an instantaneous discharge, which erodes the mold material.

[0062] Electrolytic machining, based on the principle of electrochemical corrosion, uses the mold workpiece as the anode and a specially designed tool electrode as the cathode. A direct current is passed through the electrolyte, causing the surface material of the mold workpiece to dissolve according to the shape of the tool electrode, thus machining a constricted tapered hole. Electrolytic machining has unique advantages for machining tasks with micro-diameter holes and extremely small adjacent hole spacing. By carefully designing the shape of the tool electrode to precisely fit the target constricted tapered hole, the electrolyte is evenly distributed between the electrode and the workpiece under the influence of the electric field during machining. This uniform dissolution of the workpiece surface material enables high-precision tapered hole machining without generating mechanical stress or a heat-affected zone, effectively preserving the original performance of the mold and the edge distance between adjacent holes. Furthermore, this process results in smooth inner walls and hole openings, effectively controlling burr formation. It also prevents peeling or adhesion of ceramic tubes during mold demolding, eliminating the need for frequent mold cleaning, saving time and effort, and improving manufacturing efficiency.

[0063] In some embodiments, such as Figures 3-7 As shown, the first mold a and the second mold b may include the tube structure 21 and the docking structures 22 disposed on both sides of the tube structure 21, for reference. Figure 6The docking structures 22 on both sides extend outward along the diameter direction at both ends of the semi-circular structure 21 of the tube body structure; this extension design enables the docking structures 22 to fit precisely when the first mold a and the second mold b are joined together, thereby enhancing the overall connection strength and stability of the mold.

[0064] Furthermore, the arrangement of the docking structures 22 along the length of the tube structure 21 is flexible, allowing for continuous or intermittent arrangement depending on actual production needs. When continuously arranged, the docking structures 22 extend uninterruptedly along the tube length, providing uniform and strong connection force throughout the entire mold length. This effectively prevents localized stress concentration or loosening of the connection during negative pressure filtration, making it particularly suitable for production scenarios with extremely high molding precision requirements and long ceramic tube lengths. Intermittently arranged docking structures 22 are arranged at certain intervals along the tube length. This method, while ensuring basic mold connection strength, reduces the overall weight of the mold, lowers material costs, and facilitates mold manufacturing. It is suitable for production needs that are more sensitive to cost control and have relatively moderate molding precision requirements.

[0065] In some embodiments, such as Figures 3-7 As shown, the docking structure 22 has a docking portion; the docking portion is configured as a plane, as shown in the figure. Figure 6 and Figure 7 In this embodiment, the mating parts are all designed as planar structures. This design simplifies the mold manufacturing process and reduces processing costs. The mating parts have a certain length, achieving a good sealing effect and preventing negative pressure leakage during the filtration process. Alternatively, the mating parts of the first mold a and the second mold b are mutually corrugated. This design significantly enhances the stability and sealing performance of the molds after assembly. During the assembly process, the protruding parts and the grooved parts fit tightly together, forming a mechanical locking structure, which effectively limits the relative displacement between the molds and improves the overall rigidity of the molds during the negative pressure filtration process. At the same time, the corrugated structure reduces the mating gaps, further improving the sealing performance. This design is suitable for industrial production scenarios with extremely high requirements for molding precision and sealing, such as the manufacture of high-precision ceramic filter tubes.

[0066] In some embodiments, such as Figure 3 As shown, the first mold a and the second mold b also include a support base 23. The support base 23 is located on the outside of the tube structure 21 and / or the docking structure 22 and is fixedly connected to the tube structure 21 and / or the docking structure 22. The fixed connection can be by welding, bolting, or other methods.

[0067] In practical use, especially for longer molds, ceramic tube forming dies are prone to deformation due to their own weight and external pressure during negative pressure filtration, installation, disassembly, and prolonged use, which affects the forming accuracy and quality of the ceramic tubes. The support base 23 effectively distributes the pressure and stress borne by the mold, providing additional support points and forces to maintain a stable shape in all directions. This significantly enhances the shape retention capability of long molds, ensuring good structural stability even under prolonged use and complex working conditions. This guarantees the reliability and consistency of the ceramic tube forming process, effectively improving product qualification rate and production efficiency.

[0068] In some embodiments, such as Figure 3 , Figure 4 and Figure 7 As shown, the support base 23 includes support blocks 231 respectively disposed below the docking portions on both sides, and the support blocks 231 are fixedly connected to the docking portions; the support blocks 231 are stably fixedly connected to the docking portions by welding, high-strength bolts, or other methods, providing a reliable support foundation for the mold. Optionally, the support blocks 231 can be a square tube structure.

[0069] Furthermore, a negative pressure filtration channel 231-1 is provided between the support block 231 and the tube structure 21, thus preventing direct contact between the support block 231 and the tube structure 21. This channel ensures that during the ceramic tube forming process, the negative pressure generated by the filtration system can act unimpeded on the filtration through-holes 211 on the tube structure 21, ensuring that moisture in the ceramic slurry is smoothly extracted, thereby achieving uniform stratification and porosity gradient control of the ceramic tube material. While ensuring the support effect, it effectively avoids filtration failure or localized poor forming problems caused by the support structure blocking the filtration through-holes 211.

[0070] Furthermore, the support blocks 231 are continuously or spaced out along the length of the tube structure 21. When continuously arranged, the support blocks 231 extend uninterruptedly along the length of the tube, providing uniform and high-strength support for the long mold, effectively resisting the deformation risk caused by factors such as the mold's own weight and stress generated during negative pressure filtration. This is particularly suitable for production scenarios with extremely high requirements for mold stability and sensitive molding precision. The spaced support blocks 231 are distributed at certain intervals along the length of the tube. This method can reduce the overall weight of the mold and lower material costs while ensuring the basic support strength of the mold. It also facilitates the cleaning and maintenance of the filtration channel, making it suitable for production needs with strict cost control and moderate requirements for mold support strength.

[0071] In some embodiments, such as Figure 3, Figure 4 , Figure 5 and Figure 6 As shown, the support base 23 includes at least one support piece 232 disposed below the tube structure 21. The top of the support piece 232 has an arc-shaped support portion 232-1, which is fixedly connected to the outer wall of the tube structure 21. The arc-shaped support portion 232-1 is fixedly connected to the outer wall of the tube structure 21 by welding or bonding, etc., closely conforming to the outer contour shape of the tube structure 21, providing stable and uniform support force for the tube structure 21, and further enhancing the overall stability of the mold.

[0072] Furthermore, in the circumferential direction of the tube structure 21, the arc-shaped support portion 232-1 is configured as a continuous structure or an intermittent structure; Figure 6 The illustrated embodiment uses an intermittent structure to reduce obstruction of the suction through-holes 211. The continuous arc-shaped support portion 232-1 provides all-around, uninterrupted support for the tube structure 21 in the circumferential direction, effectively preventing local deformation of the tube under stress. It is understood that, in addition to considering the effective support circumferential length, by setting the position and thickness of the support piece 232, obstruction of the suction through-holes 211 can be minimized. Specifically, the support piece 232 can be positioned at the interval between two rows of circumferential suction through-holes 211 (offset); or the thickness of the support piece 232 can be set sufficiently small to avoid affecting the suction through-holes 211. Optionally, the arc-shaped support 232-1 has a clearance hole or groove that matches the filter through hole 211 at the position corresponding to the filter through hole 211. This ensures that the arc-shaped support 232-1 supports the tube structure 21 and that the filter process is not obstructed, allowing the water in the ceramic slurry to be discharged smoothly through the filter through hole 211.

[0073] Furthermore, referring to Figure 4 When there are two or more support plates 232, the support blocks 231 are spaced apart along the length of the tube structure 21. This spaced distribution ensures sufficient support for the tube structure 21 while avoiding excessive density of support plates 232, which would increase the weight and cost of the mold. It also facilitates the inspection and maintenance of the mold and can reasonably distribute stress along the length of the tube structure 21, preventing mold damage due to stress concentration.

[0074] Furthermore, in the radial direction of the mold, both ends of the support piece 232 are fixedly connected to the support blocks 231 on both sides, such as by welding. In the longitudinal direction of the mold, the continuous arrangement of the support blocks 231 and the spaced arrangement of the support pieces 232 can effectively ensure the straightness and coaxiality of the mold.

[0075] In some embodiments, such as Figure 7 and Figure 8 As shown, the diameter of the suction filter through-hole 211 does not exceed 1 mm, and the edge distance between adjacent holes does not exceed 1 mm. Optionally, through extensive experiments and optimization design, when the mold processing hole diameter is set to 0.81 mm and the edge distance is set to 0.67 mm, the air permeability of the mold can be greatly improved.

[0076] Compared to the 1.2mm aperture and 1.1mm edge spacing commonly used in similar domestic molds, this invention can arrange more filtration holes 211 per unit area, effectively increasing the filtration area and making the water discharge of ceramic slurry more efficient during negative pressure filtration. This ensures that the ceramic tube material achieves more uniform layering and porosity gradient distribution, significantly improving the molding quality and performance of the ceramic filter tube, and meeting the stringent requirements of large-scale industrial waste gas treatment for ceramic filter tubes.

[0077] In some embodiments, such as Figures 3-5 As shown, in at least the lower mold of the first mold a and the second mold b, the straight segment 2 in the middle is separately configured from the flange segment 1 and the plug segment 3 on both sides. Separating the flange segment 1 and the plug segment 3 from the straight segment 2 allows the straight segment 2 to be machined independently with high precision. This avoids the complex operation of machining the flange segment 1 and the plug segment 3 on the entire mold, where the flange segment 1 and the plug segment 3 do not require the through hole 211 but must be avoided. This not only reduces the machining difficulty but also reduces material waste due to machining errors, significantly lowering the overall machining cost.

[0078] Once the ceramic tube is laid out, the split straight section 2 of the lower mold can act as a support component, separating from the rest of the mold, allowing the entire wet ceramic tube to be smoothly removed from the mold. This method avoids the risk of deformation or damage to the ceramic tube due to excessive demolding force when removing the wet ceramic tube using traditional integral molds, effectively ensuring the integrity of the wet ceramic tube.

[0079] As another feasible approach, if the first mold a and the second mold b are arranged side-by-side, the straight segments 2 of both molds can be further configured as separate structures. In this case, the two straight segments 2 can work together to support the wet ceramic tube. By precisely controlling the separation action of the two separate straight segments 2, the wet ceramic tube can be subjected to more uniform force during demolding, further improving the stability and reliability of demolding. This is especially suitable for demolding long, large-diameter ceramic filter tubes, providing a strong guarantee for the production of high-quality ceramic filter tubes.

[0080] In some embodiments, the connection method between the straight segment 2 and the flange segments 1 and plug segments 3 on both sides is specially designed. In actual operation, the gap between the straight segment 2 and the flange segments 1 and plug segments 3 is controlled within 0.5-1mm. This gap range ensures the tightness of the connection between the components, preventing pressure leakage during negative pressure filtration, while also avoiding disassembly difficulties due to excessively tight connections. By precisely controlling this gap, the overall sealing of the mold is ensured, while facilitating the installation and disassembly of the components, thus improving the ease of use of the mold.

[0081] As another connection method, an orifice plate is superimposed on the diameter end of one flange or plug, and a special process is used to form a concave-convex edge structure on the orifice plate. When the straight section 2 is assembled with the flange section 1 and the plug section 3, the edge of the straight mold can precisely overlap with this concave-convex edge. Since the orifice plate itself is full of holes, which is consistent with the nature of the suction through holes 211 on the straight section 2, this overlapping method will not affect the overall filtration performance of the mold. Under the premise of ensuring the normal functioning of the suction filtration, the overlapping structure of the concave-convex edge enhances the stability of the connection between the components, effectively preventing the product quality from being affected by the loosening of components during the ceramic tube forming process.

[0082] It should be noted that flange section 1 may also include a pipe section with the same diameter as straight section 2 but without the suction through hole 211.

[0083] In some embodiments, the tube structure 21 of the first mold a and the second mold b is made of 3 / 4H stainless steel. 3 / 4H stainless steel has good strength, hardness and corrosion resistance. In the process of ceramic tube forming, it can maintain stable physical and chemical properties for a long time in the face of chemical erosion of ceramic slurry and negative pressure environment in the filtration process. This avoids the mold from affecting the forming quality of ceramic tube due to corrosion, deformation and other problems, effectively extends the service life of the mold and reduces the mold maintenance and replacement costs.

[0084] In some embodiments, the thickness of the tube structure 21 of the first mold a and the second mold b is 0.6 mm. This thickness design ensures the structural strength of the mold while effectively reducing the overall weight of the mold and lowering material costs. The 0.6 mm thickness allows the mold to withstand internal pressure and maintain structural stability during negative pressure filtration, while preventing excessively thick tube walls from affecting filtration efficiency. This ensures that the moisture in the ceramic slurry can be quickly and smoothly discharged through the filtration through-hole 211, achieving uniform forming of the ceramic tube material.

[0085] In some embodiments, the inner wall of the tube structure 21 has a smooth surface with a roughness not exceeding 0.8 μm. The smooth inner wall surface effectively reduces the adhesion of ceramic slurry to the mold inner wall, lowers demolding resistance, and makes it easier for the molded ceramic tube to be removed from the mold, avoiding quality problems such as scratches and peeling on the ceramic tube surface caused by the roughness of the inner wall during demolding. Simultaneously, the low-roughness inner wall helps ensure the smoothness and flatness of the outer surface of the ceramic tube, improving the product quality of the ceramic filter tube and enabling it to better meet the requirements of industrial waste gas treatment.

[0086] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0087] In this invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or in place of features of other embodiments.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations of the embodiments of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ceramic tube forming mold, characterized in that, The ceramic tube forming mold includes a first mold (a) and a second mold (b) arranged symmetrically. The cross-section of the first mold (a) and the second mold (b) in the radial direction is semi-circular. The first mold (a) and the second mold (b) are joined together to form a complete ring forming mold. The first mold (a) and the second mold (b) each include a flange section (1), a straight section (2) and a plug section (3) arranged sequentially along their axial direction; wherein, the straight section (2) is an integral structure with a length of not less than 2500mm, and the tube structure (21) of the straight section (2) is provided with densely and evenly distributed suction holes (211), and the inner wall of the tube structure (21) has a smooth surface; The first mold and the second mold include the tube structure (21) and the docking structure (22) disposed on both sides of the tube structure (21). The docking structure (22) on both sides extends outward along the diameter direction at both ends of the semi-circle of the tube structure (21). The docking structure (22) is continuously disposed or spaced apart along the length direction of the tube structure (21). The first mold (a) and the second mold (b) further include a support base (23), which is located on the outside of the tube structure (21) and / or the docking structure (22) and is fixedly connected to the tube structure (21) and / or the docking structure (22); The docking structure (22) has a docking part, and the support base (23) includes support blocks (231) respectively disposed below the docking parts on both sides. The support blocks (231) are fixedly connected to the docking part. There is a negative pressure filtration channel (231-1) between the support blocks (231) and the tube structure (21).

2. The ceramic tube forming mold according to claim 1, characterized in that, The filtration through hole (211) is configured as a tapered hole, and the inner wall diameter of the tapered hole is larger than its outer wall diameter; or, the inner wall portion of the filtration through hole (211) is formed with a chamfered structure.

3. The ceramic tube forming mold according to claim 1, characterized in that, The mating part is set as a plane, or the mating parts of the first mold (a) and the second mold (b) are mutually concave and convex.

4. The ceramic tube forming mold according to claim 1, characterized in that, The support blocks (231) are arranged continuously or at intervals along the length of the tube structure (21).

5. The ceramic tube forming mold according to claim 1, characterized in that, The support base (23) includes at least one support piece (232) disposed below the tube structure (21), the top of the support piece (232) has an arc-shaped support part (232-1), and the arc-shaped support part (232-1) is fixedly connected to the outer wall of the tube structure (21). In the circumferential direction of the tube structure (21), the arc-shaped support part (232-1) is configured as a continuous structure or an intermittent structure; When there are two or more support plates (232), the support blocks (231) are spaced apart along the length of the tube structure (21).

6. The ceramic tube forming mold according to claim 1, characterized in that, The diameter of the filtration through hole (211) does not exceed 1 mm, and the edge distance between adjacent holes does not exceed 1 mm.

7. The ceramic tube forming mold according to claim 1, characterized in that, In the first mold (a) and the second mold (b), at least the lower mold has a straight segment (2) in the middle that is separately set from the flange segment (1) and the plug segment (3) on both sides.

8. The ceramic tube forming mold according to claim 1, characterized in that, The tube structure (21) of the first mold (a) and the second mold (b) is made of 3 / 4H stainless steel; and / or, The thickness of the tube structure (21) of the first and second molds is 0.6 mm; and / or, The roughness of the inner wall of the tube structure (21) does not exceed 0.8 μm.

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