Boron carbide ceramic nozzle and its application
Ceramic nozzles have been continuously improved and updated since they were introduced into China in the 1990s. It is mainly improved in two aspects: shape and material: 1. Shape: The shape of ceramic nozzles has gradually developed from the earlier spiral type, large volume, and two-circle spray to spiral type, vortex type, and small volume. 2. Materials: The materials have gradually developed from oxide ceramics to nitride ceramics and carbide ceramics.
Ceramic nozzles mainly include nozzles made of the following materials: (a) Oxide ceramic nozzles, because the performance of oxide ceramic nozzles is not as good as nitride ceramic nozzles and carbide ceramic nozzles, they have been gradually eliminated, and the main products in the market are nitride ceramics nozzles and carbide ceramic nozzles. (b) Nitride ceramic nozzle Nitride ceramic nozzle has the advantages of high hardness and strong wear resistance. It has both advantages and disadvantages. The material is too hard to be a spiral nozzle. (c) Carbide ceramic nozzle Carbide ceramic nozzle has the characteristics of high temperature resistance, oxidation resistance, high strength, extreme cold heat resistance, and good thermal shock resistance. Therefore, the cemented carbide nozzle has the advantages of high hardness and good ductility, and can be used as a spiral nozzle or a vortex nozzle.
Among them, silicon carbide ceramic nozzles can be used for desulfurization in power plants to remove sulfur dioxide and some polluting gases in the flue gas of power plants. In the combined cycle of flue gas and coal combustion in coal-fired power plants, the gases of the gas turbines have a common task of desulfurization and nitrate removal. The undesulfurized and unnitrated flue gas emitted by the power plant directly pollutes the atmosphere, while the unpurified combined cycle gas will harm the thermal components of the gas turbine, and its exhaust gas will also pollute the environment.
Ceramic nozzles are key components of thermal power plants, large boilers and complete sets of desulfurization and dust removal devices. Domestic reaction sintered silicon carbide desulfurization and dust removal nozzles are gradually replacing imported products. At the same time, they have excellent performances such as high strength, high hardness, strong corrosion resistance, heavy wear resistance, and high temperature resistance, and have a long service life under harsh conditions. Silicon carbide spiral nozzle is one of the very distinctive nozzles. As the spiral becomes smaller, the slurry passes through the tangent and collision of the spiral, changes direction and becomes thin slices, sprays into concentric axial cones, and the liquid in the channel Access to the nozzle chamber is unimpeded to the outlet. And it still has high absorption efficiency under extremely low operating pressure, which has been generally recognized by desulfurization systems.
Boron carbide ceramic nozzles can be used as gun nozzles in industry. Boron carbide is extremely hard and wear-resistant, does not react with acid and alkali, and can withstand high temperature, low temperature, and high pressure. Boron carbide nozzles have the above-mentioned characteristics of wear resistance and high hardness, and will gradually replace known sandblasting nozzles made of cemented carbide, tungsten steel, alumina, zirconia, silicon nitride, silicon carbide and other materials. Boron carbide ceramic nozzles can also be used in water cutting technology and have been widely used in various industries.