Carbide Nozzle for Coal Water Slurry

Coal-water slurry is a new coal-based liquid fuel that emerged from the 1970s, consisting mainly of 65% coal, 34% water and 1% chemical additives. Compared with other types of fuel, it has many advantages, such as low sulfur content, high combustion efficiency, SO2 and NOX and other pollutant emissions are lower than ordinary fuel and coal, is widely used in power plant boilers, industrial boilers And industrial kiln on behalf of the oil, on behalf of the gas, coal on behalf of the coal, is an important part of today's clean coal technology. The carbide nozzle in the coal-water slurry burner has a wide range of use, through its good fuel atomization makes coal-water slurry fuel to be more fully and effective combustion. Depending on the nature of the fuel and the requirements for the quality of the atomization, the cemented carbide nozzle can also be divided into pneumatic, mechanical, rotary cup and ultrasonic. The rationality of its structure determines the atomization effect of coal water slurry. The anti-wear and thermal shock resistance of the material determines the service life of the nozzle and directly affects the economy and safety of the CWS application.

Coal-water slurry nozzle work is mainly bear the low-angle erosion of coal-water slurry, wear mechanism is mainly plastic deformation and micro-cutting. The wear of the cemented carbide slurry nozzle is mainly grain loss, brittle fracture and grinding damage, and the higher the Co content in the cemented carbide, the greater the erosion and wear rate, so should use Co content is small or useless High hardness bonded phase alloy or direct powder metallurgy casting. The Compared to other metal materials prepared by the coal slurry nozzle, carbide nozzle has a better wear resistance and long service life (usually more than 1000h). However, the cement itself is brittle, its hardness, toughness and thermal shock resistance than other metal materials, not easy to process, not suitable for the production of complex shape of the nozzle. At present, the more common and excellent performance of cemented carbide slurry nozzle mainly in the United States, Canada and other countries of the Y-type nozzle and China's impact multi-stage coal-water slurry atomization nozzle, which is the most prone to wear parts Mosaic on the carbide to improve its wear and corrosion resistance.