Wear-resistant elbow manufacturing process
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There are many types of wear-resistant elbows, including ceramic wear-resistant elbows, bimetal wear-resistant elbows, and wear-resistant coated elbows. Recently, wear-resistant elbows have been widely used in power plants, steel mills, and coal washing plants, playing a significant role in promoting environmental protection in China. Wear-resistant elbows are generally used in applications where wear resistance is required, so the quality standards are quite strict. It is essential to ensure that each contact surface exhibits uniform wear resistance, guaranteeing that the ceramic remains wear-resistant and does not peel off. The bending radius of wear-resistant elbows is generally 3D5d. There are flange connections and direct welding connections; wear-resistant elbows must be selected based on the actual conditions at the site. According to the power industry standard DL/T680-1999 \"Technical Requirements for Wear-Resistant Pipes,\" ceramic patch-type wear-resistant pipes (TC-G) exhibit good wear resistance. The drawback of these products is the issue of detachment; the original manufacturing methods involved using ordinary adhesives for bonding or employing an arch-shaped technique for fitting. However, the ordinary bonding method often leads to detachment, and the adhesives tend to age over time. Additionally, the fitting method requires a certain thickness of the ceramic tiles, which results in high costs. Our company has addressed the issue of peeling by combining a new three-in-one wear-resistant composite technology with a bonding medium layer; moreover, the thickness can be chosen arbitrarily, making the ceramic tile wear-resistant pipeline (TC-G) product an excellent solution for coal powder pipelines and mineral powder transmission pipelines in power plants. http://www.bhgdzb.com/UploadFiles/news/2021/6/202106260859328148.jpg Manufacturing process of ceramic wear-resistant elbows: 1. Surface treatment of the workpiece – Metal surfaces develop a layer of rust over time as a result of use. Before applying the ceramic tiles, it is necessary to polish and remove this rust using sandblasting and grinding machines. If the surface is not properly polished, applying the ceramic tiles directly will be the main reason for a decrease in the adhesion strength of those tiles. During the grinding and polishing process carried out by workers, oil stains or dust inevitably remain on the metal surface. If ceramic tiles are attached without first cleaning that surface with a specialized cleaner, the tiles will not adhere firmly and may fall off. 2. Strictly adhere to the mixing ratio for the adhesive; the ceramic adhesive must be prepared in a 1/2 ratio as required, and mixed thoroughly to ensure that all components are well combined. The ambient temperature should be maintained between 5 and 40°C; if the temperature is too low, it should be raised to within this range. Construction should also be avoided in conditions of direct sunlight and strong winds, to prevent deformation caused by the thermal expansion and contraction of the ceramic tiles leading to mutual compression; moreover, strong winds can significantly reduce the bonding strength of the ceramic adhesive due to dust generation. The surface should be smooth, with even filler application and no bubbles; there should be no protruding wear-resistant ceramic pieces, as these can affect flow rate and reduce wear resistance. 3. Quality inspection: The company’s dedicated inspectors must examine each ceramic wear-resistant elbow individually, checking aspects such as its appearance, angle, and flatness, to ensure that all products leave the factory meeting quality standards. http://www.bhgdzb.com/UploadFiles/news/2021/6/202106260900172925.jpg
Could you mention what the processes for manufacturing ceramic wear-resistant elbows are?
In the process of electrostatic dust removal of flue gas in thermal power plants, a large amount of fly ash is collected through this method. The fly ash is then transported from the collection hoppers to ash storage areas or dumps, which requires transportation equipment such as pipelines. When installing the conveying pipes, whenever the direction of the pipes needs to change, ash conveyance pipe elbows are used to connect them. In existing technologies, when fly ash in motion within the conveying pipes changes direction, inertia causes severe erosion of the inner walls of the pipe bends, leading to wear and perforation of these bends. Once worn or perforated, such pipe bends must be replaced or repaired promptly to ensure normal operation. Replacing or repairing the bent sections of the ash conveying pipes that have become worn or punctured is also troublesome, and it has a certain impact on production. The technical problem to be solved is to overcome the issue of easy wear and perforation of ash transfer pipe elbows, as well as the negative impact that replacing or repairing such worn or perforated elbows has on production. By meeting people’s needs, a type of ash transfer pipe elbow with a long service life is provided, which reduces the impact on production and lowers the associated maintenance costs. 1. Design of wear-resistant elbows for ash transfer pipes: The diameter of the elbows for these pipes is DN125, with a pressure rating of PN1.0L1. The inlet volume is 250 L, while the outlet volume is 750 L. The radius of curvature is 1000. The thickness of the ceramic material is 6 mm, and that of the steel pipe is 10 mm. Flanges, counter flanges, and connecting elements are included in the design. The ceramic composite pipe consists, from the inside out, of a corundum ceramic (Al2O3) layer, a transition layer, and a steel pipe layer. The ceramic layer is formed by uniformly applying molten alumina at temperatures above 2,600°C to the inner wall of the steel pipe under the action of centrifugal force; it then solidifies into a dense, smooth layer that adheres tightly and securely to the steel pipe. Unlike traditional production methods, ceramic steel pipes manufactured using the self-propagating centrifugation technique possess a stable microstructure. A stable organizational structure also determines its excellent overall performance. It not only resists wear, possessing high hardness and strength, but also has excellent comprehensive properties in terms of resistance to mechanical and thermal shock.
Wear-resistant elbows are commonly used at the bends in pipes in steel mills, power plants, and cement factories. These elbows can be divided into ceramic wear-resistant elbows and bimetallic wear-resistant elbows. Ceramic wear-resistant elbows are often used in coal powder pipelines; they are resistant to wear and corrosion. Thanks to their ceramic material, they are lightweight and offer excellent wear resistance, which makes them widely used in pipelines for transporting powder in power plants.