Study on Wearing of Screw of Biomass Briquetting Extruder

  • R. M. Singh Royal Nepal Academy of Science and Technology, GPO Box 3323, Kathmandu


Production of rice husk briquettes, which could be used as substitute for fuelwood, was initiated in 1982 in Nepal. One technical problem of this industry is the fast wearing of the screw of the briquette extruder. Different types of welding rods were used in the welding and hardfacing of the screw and tested in the briquetting of rice husk. Results showed that the wearing of the screw takes place mainly at the first three flights of the screw from the guiding rod, where the pressure is the highest. The tests showed that tungsten carbide and austenitic electrodes can double working hours of the screw compared to the life of the screw prepared from ordinary electrodes. The use of a new welding technology - thermal powder spray technology - to uniformly coat the surface with Eutalloy also increases the working hours remarkably to more than 15 hours.