Performance and wear characteristics of ceramic, cemented carbide, and metal nozzles used in coal–water–slurry boilers

Ceramics, cemented carbides, and metals were prepared to be used as nozzles in CWS boilers. CWS burning tests in a boiler with these nozzles were carried out. The erosion wear resistance of these nozzles was compared by determining their erosion rates and hole diameter variation. Results showed that the life of the ceramic nozzles is about 30 times high than that of the metal nozzles. The wear types at the nozzle wall surface differed in various positions. The nozzle center wall section suffers form abrasive impact under low impact angles, and the damage at the center wall mainly occurs by plowing and plastic deformation for metals, and by polishing action for carbides and ceramics. The primary wear mechanisms at the exit of ceramic nozzle exhibited thermal shock damage with chipping owing to the greater thermal stresses.