Pulse combustion variable residence time drying system

Abstract

A variable residence time drying system for moist material includes a valveless pulse combustor and a drying chamber. The drying chamber includes a lower sidewall with an upward expanding configuration that defines a lower inverted partial cone, an upper sidewall with an upward contracting configuration, a lifting rotor disposed within the lower inverted partial cone to suspend material being dried within a shear/drying zone, an opening through which moist material is fed into the drying chamber, and an exit located at a top portion of the drying chamber through which dried material exits the drying chamber. The valveless pulse combustor produces drying gas and sonic vibrations that are introduced tangentially into the shear/drying zone. One or more cyclones receive dried material and collect small particles. The lifting rotor may rotate in a direction counter to a direction in which the heated drying gas is introduced into the drying chamber.