Abstract
Rate of discharge of sodium borate and boric acid powders from acrylic and brass funnels were investigated. Large particles discharge steadily from a funnel but flow behaviour seems to be different in the region below critical size. Flow rate largely depends on materials, outlet diameter, outlet length and cone angle of the funnel. Angle of repose characterized by particle size, kind of particles and the like, is an important parameter controlling flow rate of particles. Drained angle is markedly influenced by particle size in the region below critical size just as is the angle of repose and the sliding angle.
