Introduction to wear-resistant ceramic elbow linings
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I. Introduction to wear-resistant elbows: The ceramic-lined elbows are manufactured using a high-tech production process—the self-propagating high-temperature synthesis method. The tube is composed of three layers from the inside out: corundum ceramic, a transition layer, and steel. The ceramic layer is dense corundum porcelain (AL2O3) formed at high temperatures above 2200°C, and it forms a strong bond with the steel pipe through the transition layer. Composite pipes take full advantage of the high strength, good toughness, impact resistance, and excellent weldability of steel pipes, as well as the high hardness, superior wear resistance, corrosion resistance, and heat resistance of corundum ceramics, thereby overcoming the shortcomings of steel pipes such as low hardness and poor wear resistance, as well as the poor toughness of ceramics. Therefore, composite pipes possess excellent comprehensive properties such as wear resistance, heat resistance, corrosion resistance, resistance to mechanical and thermal shocks, as well as good weldability. It is an ideal wear-resistant and corrosion-resistant pipeline for transporting granular materials, for grinding, and in handling corrosive media. https://iknow-pic.cdn.bcebos.com/5243fbf2b2119313a4578bd075380cd791238dbd?x-bce-process%3Dimage%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_jpg Centrifugally cast composite ceramic wear-resistant elbowshttps://iknow-pic.cdn.bcebos.com/faf2b2119313b07edfa924681cd7912397dd8cbd?x-bce-process%3Dimage%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_jpg Spherical wear-resistant elbows, ceramic wear-resistant elbows
https://iknow-pic.cdn.bcebos.com/11385343fbf2b211803af12eda8065380cd78ebd?x-bce-process%3Dimage%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_jpg Ceramic wear-resistant elbows
II. Performance characteristics of wear-resistant elbows
1. Wear resistance: The ceramic lining layer in ceramic wear-resistant elbows contains over 95% Al2O3, with a microhardness ranging from HV1000 to HV1500. As a result, these elbows exhibit excellent wear resistance. Their wear resistance is more than ten times greater than that of quenched medium-carbon steel, and they outperform tungsten-cobalt hard alloys. 2. Corrosion resistance: Ceramics are neutral materials with stable chemical properties; they exhibit excellent corrosion and acid resistance, being able to withstand various inorganic acids, organic acids, and organic solvents. Their resistance to corrosion is more than ten times that of stainless steel. 3. It has excellent heat resistance; it can withstand temperatures above 2000°C and can operate continuously within the range of -50°C to 900°C. 4. Easy to weld: The ceramic wear-resistant elbow can be connected by welding the outer steel pipe. It can also be joined using methods such as welding, flanges, or flexible quick couplings, making installation very convenient. The manufactured composite ceramic wear-resistant elbows form a uniform, dense, and smooth-surfaced ceramic layer as well as a transition layer under high temperature and high speed conditions. Furthermore, at normal operating temperatures of 850–900 degrees, the ceramic material does not fall apart; it is also lightweight. Composite ceramics utilize hardness for wear resistance, thereby replacing the previous approach of relying on thickness for this purpose. Currently, pipe fittings such as straight pipes, elbow pipes, and tees perform very well in industries with severe wear. III. Applications of wear-resistant elbows 1. Wear-resistant ceramic pipes in the power industry: silos, hoppers, and funnels in the raw coal handling system, as well as powder delivery pipelines. 2. Coal industry: heavy mineral coal separation pipelines in coal preparation plants, wet coal conveying systems, and sediment backfilling in mining. 3. Mining industry: Mine backfilling, concentrate powder transportation, tailings transportation pipelines. 4. Steel industry: coke pellet conveying pipes, coal grinder pipes, separators, cones, and separation baffles. 5. Cement industry: coal powder transportation, mineral powder transportation. 6. Machinery industry: Linings for equipment in power plant powder generation, dust removal, and ash discharge systems, as well as linings for dust removal equipment in steel mills. IV. Pictures of wear-resistant elbows https://iknow-pic.cdn.bcebos.com/a50f4bfbfbedab64d3e66cbde736afc379311e32?x-bce-process%3Dimage%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_jpg Wear-resistant elbows for backpacks
Types of ceramic-lined wear-resistant elbows: 1. Welded ceramic wear-resistant elbows involve using high-temperature adhesive to attach aluminum oxide ceramic sheets with holes in them to the inner wall of the elbow; simultaneously, spot welding is used to firmly weld the ceramics to the inner wall of the steel pipe through those holes. To protect the welded steel bowl, a ceramic cap is screwed on top of it. Not only are the ceramic tiles pressed against and interlocked with one another, but each tile also forms a trapezoidal angle, ensuring a tight fit between them without any gaps ； When a piece of the surrounding material is firmly embedded, a 360° mechanical self-locking force is created between the ceramic pieces (this technique was already used in Chinese bridge construction centuries ago). Not only are the ceramic tiles pressed against and interlocked with one another, but each tile also forms a trapezoidal angle, ensuring a tight connection between them without any gaps.
Spherical elbows are widely used in the ash transportation industry; they offer better wear resistance and do not get clogged with ash. The requirements for manufacturing spherical wear-resistant elbows are as follows: 1. The material for spherical elbows must be high-quality carbon steel; for export powder pipe elbows and spherical elbows, the material must be seamless steel tubes or steel balls. All spare parts are required to have a corundum ceramic lining, and PN16 flanges must be provided at both ends of the parts to facilitate the installation. The ceramic lining should be dense and have a smooth surface; there shall be no grooves, bubbles, or separation between the wear-resistant layer and the steel pipe. The wear-resistant ceramic layer on the lining is uniform, offering good wear resistance; its average thickness is not less than 4 mm, its Mohs hardness is above 9.0, and the thickness of the metal wall is ≥8 mm. The strength of ceramic-lined composite steel pipes is not less than 1100 kg/m3; the density of the ceramic layer is not less than 3.85 g/cm2. The compressive shear strength is 15–20 MPa, while the compressive strength is 300–350 MPa. The outer surface of the spare parts is coated with an anti-rust treatment, in black color. 2. The length of the straight sections at both ends of the spherical elbow shall be no less than 400 mm; a short fitting along with an internal threaded plug for the DN40 assist air supply pipe is provided at the 180° direction of the outlet pipe. 3. The metal layer of all spare parts shall be coated with two layers of rust-inhibiting primer and two layers of black topcoat, to ensure the integrity of the paint finish. Spherical wear-resistant tee, boxed spherical tee, spherical elbow