Precautions for purchasing wear-resistant ceramic elbows

Technical requirements: 1. The elbow shall be equipped with an inner ring-shaped ceramic tube; the thickness of the ceramic layer must be 10 mm or more, while the thickness of the outer steel tube must be 5 mm or more. The service life is 1 year, and in the event of wear or dust leakage within this period, free replacement will be provided (including installation). Between each pair of tubes, ring-shaped ceramic filler of the same thickness is used to ensure strong bonding and seamless transitions. The elbow has a smooth transition with a smooth and even surface, and the height difference is <1mm. Bending angle deviation ±0.3°. It also possesses good thermal stability, ensuring long-term normal operation. Seamless steel pipes with an additional 150 mm length at each end of the elbow. There are no special requirements for on-site welding of the product; proper bevels should be created to ensure good weldability when the product is welded at room temperature on site. 2. The specifications and dimensions of the elbows shall comply with the requirements of the drawings. 　Due to the smooth inner surface of the cerametallic elbow and its resistance to rusting, the friction coefficient of clean water is lower than that of seamless pipes of the same specification; as a result, the operating resistance is reduced, which helps to cut down on operating costs. 　 　　Good temperature resistance: Ceramic elbow pipes can be used normally over a long period in temperatures ranging from -50 to +900°C, with a linear expansion coefficient of 6–8×10-6/°C. Therefore, it has good thermal shock stability.

Elbows are pipe fittings in piping systems that experience significant wear; the degree of wear on them is more than 6 times that of straight pipe sections. If ordinary steel elbows are used, their service life is short, requiring frequent maintenance and replacement. In contrast, ceramic elbows extend the service life by more than 10 times, thereby prolonging the lifespan of the pipes and achieving energy savings. Ceramic elbows are formed by shrimp-waist welding and sintered at high temperatures in a centrifugal casting machine. 2.1. The medium transported inside the pipeline is air or a coal powder mixture. The normal operating temperature ranges from 80°C to 100°C; in special cases, it can reach 350°C. The normal operating velocity is 22–28 m/s, while the normal wind pressure is 5–15 kPa. Elbows are suitable for use in environments where there is gas-powder erosion at velocities of 35 m/s. 2.2 Ceramic elbows ensure a service life of over 10 years. 2.3 Ensure that the internal flow diameter is 610 mm. 2.4. The ceramics will not crack, age over time, or fall off. If such issues as falling off or cracking occur within the guaranteed service life, the winning bidder shall replace them at no cost. 2.5. After the ceramic tiles are bonded, the surface irregularity between the two tiles shall not exceed ±1.0 mm. 2.6. The lining is made of 95% corundum ceramic, with a hardness of HRA≥90; the thickness of the ceramic is not less than 12 millimeters. The ceramic uses a dovetail fitting design, with each piece having four edges that interlock with one another. Each piece also has welding holes, and after welding, ceramic welding plugs are placed over them. 2.7. To ensure smooth flow in the pipeline, seamless steel pipes (with a wall thickness of not less than 10 mm) are used for medium-frequency overall extrusion; the ceramic-coated section of the pipe must be seam-free, and the shrimp-shaped design is not permitted.

According to the power industry standard DL/T680-1999 \"Technical Requirements for Wear-Resistant Pipes,\" ceramic patch-type wear-resistant pipes (TC-G) offer the best 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 installation; however, the adhesive method often leads to detachment, and the adhesives tend to age over time. The installation method based on an arch shape requires a certain thickness of the ceramic tiles, which results in high costs. Our company utilizes a new three-in-one wear-resistant composite technology in combination with a high-strength bonding medium layer to completely eliminate the problem of peeling; moreover, the thickness can be chosen arbitrarily, making the ceramic tile wear-resistant pipeline (TC-G) product the best solution for coal powder pipelines and mineral powder conveyance pipelines in power plants.

Ceramic wear-resistant elbows are manufactured using a self-propagating reaction process, via a chemical reaction and centrifugal casting technique. The ceramic layer is formed at high temperatures above 2200°C to create dense corundum porcelain (AL2O3), which forms a strong bond with the steel pipe through an intermediate 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.

Wear-resistant ceramic pipes, also known as ceramic composite pipes or ceramic wear-resistant pipes, are increasingly widely used due to their excellent wear resistance and low weight. They are suitable for transporting materials containing solid particles and corrosive substances, as well as high-temperature corrosive gases and sulfur-containing hot springs. They find extensive application in dust removal pipelines in steel mills, ash removal pipelines in power plants, cement factories, and the power industry; they are also used in various other industries such as metallurgy, coal, petroleum, chemicals, building materials, and machinery. When transporting materials with high abrasiveness through pipelines (such as ash, coal powder, mineral powder, tailings cement, etc.), the carbon steel pipes used in power plant ash conveyance systems wear out after just a few months, whereas abrasion-resistant pipes for ash transport can be used for a long time. I. Production process of wear-resistant ceramic tubes. Ceramic wear-resistant steel tubes are manufactured using the self-propagating high-temperature synthesis – centrifugation method. In these ceramic steel tubes, the melting point of corundum is 2045°C; due to the manufacturing process, the structure of both the corundum layer and the steel layer is special, as is the stress field in them. At room temperature, the ceramic layer is under compressive stress while the steel layer is under tensile stress; these two forces are opposite yet complementary to each other, forming a balanced whole. Only when the temperature rises above 400°C, due to the difference in their thermal expansion coefficients, the new stress field generated by thermal expansion cancels out the existing stress field in the ceramic steel pipe, allowing the ceramic layer and the steel layer to be in a state of free equilibrium. When the temperature is raised to 900°C and the lined ceramic wear-resistant steel pipe is placed in cold water and immersed repeatedly, the composite layer shows no cracks or fragmentation, demonstrating heat shock resistance that is unmatched by ordinary ceramics. II. Performance characteristics of wear-resistant ceramic pipes 1. Good wear resistance: The ceramic composite pipe has an inner lining made of corundum ceramic (α-Al2O3), giving it a Mohs hardness of 9.0, which is equivalent to HRC 90 or higher. Therefore, it exhibits high wear resistance against abrasive media transported in industries such as metallurgy, power generation, mining, and coal mining. Industrial operation has proven that its wear resistance lifespan is ten times, or even dozens of times, that of quenched steel. 2. Corrosion resistance and anti-scaling property: Since the steel-ceramic layer is (a-AL2O3), it has neutral properties. Therefore, it possesses acid and alkali resistance as well as seawater corrosion resistance, along with scale prevention properties. 3. Low operating resistance: SHS ceramic composite pipes have a smooth inner surface, do not rust, and lack the protruding spiral patterns found on the inner surface of seamless steel pipes. According to tests conducted by relevant testing institutions on the internal surface roughness and flow resistance, the smoothness of its internal surface is superior to that of any metal pipe, with a flow resistance coefficient of 0.0193, which is slightly lower than that of seamless pipes. Therefore, this pipe features low operating resistance, which can reduce operating costs. 4. It has good temperature resistance and resistance to thermal shock, as this corundum ceramic (a-AL2O3) possesses a single, stable crystalline structure. Therefore, the composite pipe can operate normally over a long period in a temperature range of -50 to 700°C. The linear expansion coefficient of the material is 6-8×10-6/°C, which is approximately half that of steel pipes. The material has good thermal stability. 5. Low cost: Ceramic composite pipes are lightweight and come at an affordable price. 50% lighter than cast stone pipes of the same inner diameter ； It is 20-30% lighter than wear-resistant alloy pipes, and boasts good wear and corrosion resistance; its long service life reduces costs related to supports, handling, installation, and operation. Through a comparison between the project budgets prepared by the relevant design institutes and construction units and the actual costs of the project, it was found that the cost of this type of pipe is comparable to that of cast stone pipes; compared with wear-resistant alloy pipes, its cost is reduced by about 20%. 6. Easy to install and construct: The pipe is lightweight and has good weldability. Therefore, methods such as welding, flanges, and quick connections can be used, which facilitates construction and installation while reducing installation costs. III. Application scope of wear-resistant ceramic pipes: Due to their wear resistance, corrosion resistance, and heat resistance, these pipes can be widely used in industries such as electricity, metallurgy, mining, coal, and chemicals for transporting abrasive particles and materials such as sand, stones, coal powder, ash, and aluminum melt, as well as corrosive fluids. They represent an ideal choice for pipes that need to withstand wear and corrosion. 1. Applications in the metallurgy and power industries: The metallurgy and power industries require a large amount of metal pipes each year for transporting coal powder, ash, sludge, lime-gypsum slurries, and similar materials. Replacing other pipes with ceramic composite pipes offers advantages such as high wear resistance, long service life, easy installation, and significant economic benefits. Through operation in industrial facilities such as Changrun Thermal Power Plant in Liaocheng, Shandong; Liaocheng Zhonghua Power Plant; Beijing Beixin Building Materials Group; Hebi Power Plant in Henan; Pingliang Power Plant in Gansu; Taiyuan Coal Preparation Plant; Shimen Power Plant in Hunan; Gequan Coal Preparation Plant of Hebei Jinniu Energy Co., Ltd.; and Xingtai Coal Preparation Plant, its service life is ten times or even dozens of times longer than that of steel pipes. 2. Applications in the mining and coal industries (1) Mines: The transportation of mine fill, concentrate powder, and tailings causes severe wear on pipelines. The pipeline systems used for transporting mine powder in places such as Panzhihua and Daye mines previously had a service life of less than one year; by using this type of pipeline, the service life can be increased by about 5 times. (2) Coal: Wet transportation is commonly used for coal washing and long-distance pipeline transport of coal; therefore, the pipes used must be both wear-resistant and corrosion-resistant. Pipes of this type can serve as long-lasting transportation solutions, offering significant economic benefits. 3. Others: (1) This tube does not contaminate nor stick to molten aluminum. An ideal material is one that enables the manufacture of aluminum melting equipment, aluminum melt transfer pipes, and lift pipes that are sensitive to iron contamination and require heavy labor for cleanup and maintenance after use. (2) This pipe has good wear resistance and resistance to thermal corrosion. Suitable for transporting corrosive materials containing solid particles, as well as corrosive media such as high-temperature corrosive gases and sulfur-containing geothermal water.

2.1 Purpose: To be installed in the pipeline network of the environmental dust removal system. 2.2 The material for wear-resistant pipe fittings is wear-resistant ceramic; elbows are equipped with wear-resistant embedded ceramic, and tees have ceramic plates attached to them. Main components of the wear-resistant layer: contains about 95% Al2O3 ； The thickness of the wear-resistant layer is ≥10mm. 2.3 Wear layer properties: Density: ≤3.65g/m3 ； Mohs hardness: ≥9.0 ； Compressive strength: ≥102MPa ； Bending strength: ≥20MPa ； 2.4 The wear-resistant ceramic is required to be impact-resistant, non-falling off, and free from cracking. Areas such as the rear of the sintering chamber must be heat-resistant and not crack due to temperature fluctuations. 2.5 The dust concentration in the medium is 15–20 g/m3, with a flow velocity of ≤17.0–20.0 m/s. 2.6 Operating pressure ≤ -6000 Pa. 2.7 For dust removal and wear-resistant pipe fittings, consideration should be given to the connection with the pipeline; 100 mm of interface pipe should be left at the inlet and outlet. Except for the connections to equipment and accessories, which are made using flanges, all other connections are made by welding. The inner diameter of the wear-resistant layer of the wear-resistant pipe fitting is identical to that of the connecting pipe, as shown in the schematic diagram. The wall thickness of the outer shell of the wear-resistant fitting ≥ the wall thickness of the connection pipe

Technical data on spherical wear-resistant elbows: In the pneumatic conveying systems of cement plants and power stations, spherical elbows are used as alternatives to conventional wear-resistant pipe elbows. Thanks to their simplicity in fabrication, ease of installation, and good durability, they are increasingly employed in pneumatic conveying systems in large and medium-sized power stations as well as cement plants. However, since the required quantities are usually small and the repairs need to be carried out promptly, it is necessary to choose manufacturers who are reputable in order to ensure the quality of the elbow fittings as well as timely delivery. The production of spherical wear-resistant elbows must be carried out strictly in accordance with the manufacturing process to prevent substandard product quality. It features a spherical wear-resistant elbow structure; the spherical elbow is composed of a sphere, two straight pipes, and flanges or slip-on flanges. The degree of the spherical elbow can be determined according to on-site requirements; common angles are 45°, 90°, and 135°. There are mainly two types: wear-resistant spherical elbows and non-wear-resistant spherical elbows. The wear resistance of wear-resistant spherical elbows is achieved through the use of high-chromium cast iron (bimetallic material) for manufacturing them, that is, cast elbows. For straight pipes, either high-chromium cast iron or aluminum oxide can be used for wear resistance; aluminum oxide offers lower costs compared to high-chromium cast iron, but it can only be used in situations where the particles in the medium are small and the impact force is low. It is much more reliable than bimetallic materials, does not tend to detach easily, provides longer wear resistance, and has a longer service life.

I’ve learned something new – wear-resistant elbows

:victory::handshake

Density: ≤3.65g/m3 Is the density that low?