Application of SiC ceramic sintered products

Application of SiC ceramic sintered products

The process of reaction sintering silicon carbide is to add silicon powder and carbon (graphite, carbon black, etc.) into silicon carbide and bury carbon at 1450 ℃, so that silicon powder reacts with carbon to form low temperature type β- SiC  , The SiC products prepared by this process have good properties and high strength. Because the products generally contain 8% - 15% free silicon and a small amount of free carbon, the service temperature is generally lower than 1400 ℃. Its thermal conductivity and impact resistance are good, but its strength, hardness and corrosion resistance are poor. The size of reaction sintered SiC products is almost the same before and after sintering, so it can be processed into any shape and size after molding, especially suitable for large-scale and complex shape products.

Reaction sintering silicon carbide is a kind of high-tech industrial ceramic material. It has high temperature strength, strong oxidation resistance, strong acid and alkali corrosion resistance, good thermal stability, high thermal conductivity, hardness second only to diamond, and high wear resistance. It has been processed into silicon carbide burner sleeve, silicon carbide beam roller, silicon carbide cold air pipe, silicon carbide radiation pipe, silicon carbide preheating pipe air guide sleeve, Silicon carbide sandblasting nozzle, silicon carbide desulfurization nozzle, silicon carbide wear-resistant lining and other wear-resistant, high temperature, corrosion-resistant products are widely used in electric power, steel, ceramics, high temperature equipment, petroleum, chemical industry, environmental protection, machinery manufacturing and other industries, and widely recognized by all sectors of society.

1、 Reaction sintered silicon carbide burner sleeve

Silicon carbide burner sleeve: This product has high temperature strength, oxidation resistance, wear resistance, rapid cooling and heating resistance, long-term high temperature use, no fracture, no deformation, can effectively control the temperature balance in the kiln, has been widely used in daily porcelain, sanitary porcelain, building ceramics and other high-temperature kilns, such as (roller kiln, tunnel kiln, shuttle kiln, etc.) kiln.


Fig. 1      silicon carbide burner sleeve

2、 Reaction sintering silicon carbide desulfurization nozzle

Reaction sintering silicon carbide desulfurization nozzle is the key component of thermal power plant, large boiler and complete set of desulfurization and dust removal device. The localization of silicon carbide desulfurization nozzle has replaced the imported product and filled the domestic blank. The product has excellent performance of high strength, high hardness, strong corrosion resistance, severe wear resistance and high temperature resistance, and has extraordinary service life under harsh conditions, The commonly used types are spiral nozzle and swirl nozzle.

1). Silicon carbide spiral desulfurization nozzle

When the nozzle is rotated, the outer part of the liquid impinges on the spiral surface of the nozzle at a certain angle, thus changing the jet direction and leaving the nozzle. The angle between the streamline and the center of the jet surface (spiral angle) of different layers of cone gradually decreases, and the liquid does not receive any obstruction in the channel from entering the nozzle cavity to the outlet, The spray area of the primary spiral nozzle is a solid conical fog field composed of a series of continuous concentric axis hollow cones. The spiral nozzle can provide different spray angles of 60, 90, 120 degrees and so on, so as to meet different engineering requirements, and has a high absorption efficiency under the lowest pressure, which is generally recognized by the desulfurization system. The streamline design from the inlet to the outlet of the nozzle chamber makes the resistance coefficient to the lowest. Therefore, the advantage of the spiral nozzle is good atomization effect, but the disadvantage is easy to scale and block.


Figure 3      silicon carbide swirl nozzle

2). SiC swirl nozzle

Silicon carbide swirl nozzle is divided into silicon carbide hollow cone, solid cone, silicon carbide one-way double head high efficiency nozzle and silicon carbide bidirectional nozzles. Swirl nozzle is the swirl chamber which is injected into the nozzle from tangent direction, and then ejected from the entrance hole with a right angle. The whole grouting is formed without internal parts leaving, and the spray shape is hollow conical or solid conical. The spray area is annular, and there are various spray angles and flow designs. The swirl nozzle has small spray and uniform swirl channel, and the nozzle is not easy to jam.

The high-pressure pump is used to make the slurry get higher pressure and enter the swirl chamber of the nozzle from the tangential inlet. The slurry gets rapid rotation in the swirl chamber. According to the principle of conservation of rotational momentum moment, the slurry accelerates to rotate to form a circular membrane. The static pressure energy of the slurry changes into the forward kinetic energy of the slurry at the nozzle. When the slurry is ejected from the nozzle, the slurry membrane becomes elongated and thin, Finally, it splits into small droplets to form a taper slurry fog.


Figure 3      silicon carbide swirl nozzle

3、 Reaction sintered silicon carbide beam

The weighing frame support of reaction sintered SiC beam shuttle kiln, tunnel kiln, double-layer roller kiln, industrial furnace and other high-temperature kiln sintering products has good high-temperature oxidation resistance, bending resistance, thermal shock resistance, long-term use is not easy to deformation and other characteristics.


Figure 4      silicon carbide beam

4、 Reaction sintered silicon carbide roller and cold air pipe

Reaction sintered silicon carbide roller bar and cold air pipe have the characteristics of good thermal stability, thermal shock resistance, oxidation resistance, high temperature creep resistance, high temperature resistance to blast impact, long-term use, not easy to deform and bend, and their service life is far longer than other materials. They have been widely used in the high-temperature quench section of high-temperature roller kiln in building ceramics roller kiln, lithium battery and other industries.


Figure 5       silicon carbide cold air duct

5、 Silicon carbide radiant tube and preheating tube heat exchanger

Silicon carbide radiant tube with good thermal conductivity, it can be used in the return processing line of iron and steel metallurgy industry, and is suitable for the heat conduction device and heat dissipation device under the conditions of high temperature, high corrosion and wear. Silicon carbide heat exchanger and preheating tube is a new type of tubular high temperature heat recovery device, which can be widely used in metallurgy, machinery, building materials, chemical industry and other industries to directly recover 850-1400 ℃ high temperature flue gas waste heat from various industrial kilns, so as to obtain high temperature combustion air or process gas.

The product has good heat conduction performance, which is used in annealing line of iron and steel metallurgy industry, and is suitable for heat conduction device and heat dissipation device under high temperature, high corrosion and high wear conditions.


Fig. 6      heat exchanger with silicon carbide radiant tube and preheating tube

6、 SiC frame type energy saving kiln furniture

The SiC frame type energy-saving kiln furniture is a high-temperature load-bearing structure frame suitable for tunnel kiln, shuttle kiln, part of roller kiln and other kilns. It has high temperature strength and good thermal conductivity. The frame type structure adopts the combination of perforated column, main beam, secondary beam or ultra-thin kiln plate. The number and height of product layers can be freely adjusted, Moreover, the frame structure greatly reduces the overall weight of the kiln furniture, facilitates the operation and greatly increases the loading density of the product. Due to the excellent thermal conductivity of the reaction sintered silicon carbide material, the SiC frame type energy-saving kiln furniture can save at least 20% energy compared with the traditional kiln furniture, and the service life is greatly increased. At present, the reaction sintered silicon carbide frame type energy-saving kiln furniture has been used in daily porcelain, It is widely used in ceramic industry such as sanitary ware, high voltage electric porcelain and so on.


Figure 7      SiC frame type energy saving kiln furniture

7、 High wear resistant silicon carbide lined composite pipe  

Silicon carbide wear-resistant lining: reaction sintered silicon carbide wear-resistant lining body has high chemical corrosion resistance, Mohs hardness is about 9.6, hardness is second only to diamond, with high wear resistance, high temperature resistance and self-lubricating performance, low friction coefficient, light weight and high strength, service life is several times of general wear-resistant materials, has been widely used in cyclone lining, mine, Lining of wear-resistant and corrosion-resistant pipe fittings for metallurgy and electric power.


Figure 8     high wear resistant silicon carbide lined composite pipe

The atmosphere sintering furnace developed by Haoyue Technology (as shown in the figure on the left below) can meet the requirements of sintering silicon carbide materials in protective atmosphere. As shown in the figure on the right below, it is a vacuum hot pressing furnace, which can sinter silicon carbide materials under pressure. It has the advantages of good compactness and excellent physical properties.


Haoyue technology is a high-tech enterprise integrating R & D, production and sales of electric furnace. The company has been focusing on advanced ceramics and composite materials, semiconductor materials, carbon materials and lithium and new energy materials and equipment in four major fields, with rich industry experience and professional technology, dedicated to serving customers, providing perfect integrated industrial solutions.

Updated date: 2021-04-26
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