CERAMIC LINED PIPE
Alumina ceramic patch wear-resistant tube
Alumina ceramics are a type of ceramic material with greater than 92AL2O3 as the main raw material and corundum (α-AL2O3) as the main crystal phase. It has excellent comprehensive technical properties such as high mechanical strength, high hardness, high high-temperature insulation resistance, chemical corrosion resistance and good thermal conductivity. It has high density, low wear, impact resistance, smooth surface and convenient construction. It is mainly used in the wear-resistant lining of equipment in industries such as coal, coal preparation, steel, mining, and thermal power plants. It is especially suitable for heavy medium coal pipelines in coal preparation plants, and the conveyor channels, spiral pipe discharge ports of mines and docks, and dust equipment, etc., which are subject to heavy wear.
Alumina lined ceramic wear-resistant pipe fittings are widely used in developed countries in Europe and America. After the imported coal preparation technology entered my country in the 1980s, it has gradually occupied a dominant position in my country in recent years and is currently the product with the longest wear-resistant life.
- Unique pasting technology
At present, our factory uses traditional strip and mosaic ceramic pieces. After long-term operation, the glue gradually loses its original chemical properties, and the ceramic pieces will immediately fall off in a large area, seriously affecting the normal operation of production. In response to the domestic ceramic shedding, our company has developed "three insurances" after years of practical experience: introducing the advanced technology of Mogo High-Tech in the UK, using the arch principal design, and tailoring various arcs of buckle groove self-locking arc ceramic pieces according to the size of various pipe diameters to ensure that there is no gap between the ceramic and the pipe wall. It completely solves the problem of ceramic shedding and fills the domestic gap.
The ceramic pieces form a 360-degree mechanical self-supporting structure (they will not fall off even without glue). The ceramic pieces are close to the inner wall of the steel pipe. The edges of all ceramic piece contact surfaces are designed in a conical shape. The ceramic pieces are interlocked to ensure that the ceramic pieces will not fall off. The gap between the ceramic piece and the inner wall of the steel pipe is filled with a special wear-resistant and heat-resistant adhesive glue, which provides double protection. Ensure that the ceramic piece will not fall off permanently.
- High-precision tile cutting
The maximum elbow angle design does not exceed 15 degrees. The width, taper of the corners and the angle of the joint are designed by CAD, and the ceramic blocks are precisely cut by diamond cutting blades. The gap between the ceramic blocks in the direction of material flow is less than 0.5mm. The gap between the ceramic blocks in the direction of the material flow is no more than 1mm, and the height difference between adjacent ceramic blocks does not exceed 1mm.
- Able to withstand harsh working conditions
Since inorganic binder and welding process are used as the connection method between ceramic and steel pipe, the elbow can withstand the greater impact force generated by the material and be used under high temperature conditions. The alumina ceramics produced by our company are made of high-purity, ultra-fine, single and narrow particle size, and high-quality alumina powder treated by spray drying and granulation as raw materials, scientific formula component design and optimized sintering process. The green body only needs to be sintered at a temperature of 1520℃ to make the material fully dense. The lower sintering temperature ensures that the material has a fine crystal structure and solves the problem of deformation.
According to the size of alumina ceramic products, the forming process of the blank can be dry pressing isostatic extrusion, casting and hot die casting. For this, pipeline ceramics are made by high-pressure pressing of powder in a large tonnage press to ensure that the blank has the following advantages:
(1) The blank body has high pressing density and uniform distribution.
(2) High dimensional accuracy.
(3) Easy to mass produce and low preparation cost.
- Service life: Under normal working conditions, the straight pipe is guaranteed to be used for 3 years, and the bent pipe is guaranteed to be used for 2 years.
The alumina ceramic material is selected for high hardness and good wear resistance. The thick ceramic block is used as the lining. The thickness of the lining ceramic layer has various specifications of 4-25mm, which is much larger than the thickness of 3mm and 5mm of the general small ceramic pieces and the centrifugal composite cast pipe ceramic layer. Therefore, the service life is very long. Under normal working conditions, the service life of the lining with a thickness of 15mm can reach more than 15~20 years, and the service life of the lining with a thickness of 25mm can reach more than 30 years.
- Easy installation
The outer steel shell (carbon steel or stainless steel, 6-12mm thick) is lined with a ceramic layer. The port connection form can be in various forms according to different design requirements. The elbow has the advantages of light weight, small size and good weldability in on-site construction.
Advantages of alumina ceramic patch wear-resistant tube
- High hardness
The HRC of alumina ceramics is ≥80, which is second only to diamond in hardness and far exceeds the hardness of wear-resistant steel and stainless steel.
- Wear-resistant
Alumina ceramics use a unique formula of alumina and a variety of wear-resistant materials, dry pressed, and have the characteristics of high density, high toughness, and wear resistance.
- Corrosion and high temperature resistance
Alumina ceramics are inorganic oxides with extremely high molecular structure stability, no electrochemical corrosion, and can withstand corrosion from various acids, alkalis, salt solutions and organic matter. Ceramics can withstand temperatures up to 1000°C.
- Good self-lubrication and not easy to scale
Alumina ceramics have good self-lubrication and non-adhesive properties, and the roughness is only 1/6 of that of steel pipes. The flow resistance is small, and the inner diameter design can be reduced by about 15% compared with steel pipes. As long as the medium flow rate does not exceed 2.5 m/s, scaling will not occur, which reduces the daily maintenance cost and the labor intensity of workers.
- Shock resistance
Our company uses wear-resistant ceramics and introduces Cr2O3 and TiO2, which are very similar to the alumina lattice, into the formula, which form a solid solution with alumina during the sintering process, which plays a role in refining the grains, promoting sintering and improving fracture toughness. As a result, the fracture toughness of the wear-resistant ceramics KIC≥3.8Mpa/㎡
- Strong bonding
We use imported special adhesives to bond ceramic linings to steel plates. This product has the characteristics of strong bonding, good heat resistance, acid and alkali resistance, corrosion resistance, and aging resistance. As a special adhesive for bonding ceramic linings of our company, it has been used by hundreds of customers in the past ten years with very good reliability. So far, there has not been a single case of product shedding. The special adhesive has a maximum temperature resistance of 700℃. At the same time, the lining and equipment are suitable for the wear of material conveying systems with large impact and severe wear, such as coal preparation and transportation systems, steel, smelting and sintering plants, etc. The temperature range of the special glue for conveying slurry in mining is -20℃~150℃.
- Lightweight and easy to connect
Its density is 3.6g/cm3, which is only one-third of that of steel, reducing the weight of the pipeline.
It can be connected in a variety of ways: flange, slip-on flange, quick connector, welding.
Our company has developed a welded alumina ceramic wear-resistant lining plate for the wear of materials transported by equipment in industries such as coal preparation. Its characteristics are: the ceramic block and the steel plate adopt a welding + bonding structure, which greatly strengthens the bonding force between the ceramic block and the substrate and never falls off (suitable for large pipe diameters).
Application
- Coal preparation plant operation pipeline
- Powdered coal conveying system and dry ash conveying pipe of thermal power plant
- Pebble coal system of thermal power plant
- Other powder and particle pneumatic conveying system
- Hydraulic slag conveying system and slurry conveying with larger particle size
The following is a schematic diagram of ceramic wear-resistant pipe
The production of alumina ceramic lined composite pipes is mainly divided into three parts:
The outer wall of the composite pipe uses carbon steel pipe(or stainless steel pipe) as the base material. According to the drawings, the processes of cutting, welding, rust removal, etc. are carried out to process the outer wall of the composite pipe. The pipe fittings of the wear-resistant pipe use lined ceramic sheets (rings). Its production process is carried out under strict quality control and supervision. The production of lined ceramics mainly undergoes processes such as powder preparation, pressing of ceramic sheets (rings), sintering and molding to form lined ceramic sheets (rings). On the premise that the outer wall steel pipe and the lining ceramics are qualified, the lining ceramics are pasted to the inner wall of the steel pipe with imported adhesives, and then processed and anti-corrosion treated to make wear-resistant composite pipes. The products are strictly inspected, and the qualified composite pipes can be packaged and shipped.
Alumina ceramic tile production process:
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Ball milling |
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Packing |
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Inspection |
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Granulation |
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Pressing |
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Sintering |
Alumina ceramic composite pipe production process:
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Cutting and assembly |
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Welding |
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Sandblasting |
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Inspection |
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Painting anti-corrosion |
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Finished products and packaging |
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Paste the tiles |
Cutting and assembly
The CNC intersecting wire cutting machine ensures cutting accuracy.
Welding
The welding process specifications comply with the American ASME standard, and the project's process specifications WPS, welding process qualification record PQR, and welder skill qualification WPQR are implemented. Non-destructive testing can be performed on each pipe fitting according to customer requirements, supporting PT (color flaw detection), MT (magnetic particle testing), and UT (ultrasonic flaw detection).
Sandblasting
All pipe fittings are rust-free by steel shot blasting, and the grade complies with GB8923-88 and reaches Sa2.5 standard. The process control follows the Rust Removal Process Regulations.
Paste the tiles
We strictly control the product quality of ceramic tiles and equip them with the most suitable sizes according to product specifications.
Painting for anti-corrosion
After strict rust removal, the pipe fittings are then put into the painting process after porcelain cladding.
