Continuous or semi-continuous, multiple chamber agitated mixer for gas treatment or drying of particulate solids has communicating chambers each with a central axial agitator shaft

摘要

A mixing and treatment arrangement for granular or powdered solids has, at least partially enclosed , communicating chambers (G1 - G5), of rotational symmetry, each with a central, axial agitator shaft having a radial arm (RN) to which is attached a spiral ribbon blade (W1-W5). One or more of the agitator shafts contain an axial bore for conducting a gas flow from a pressurized supply, to distributor orifices in the trailing edge of the radial arms. The device may be used for drying solids by passing hot vapor or gas , e.g. steam , air, nitrogen or carbon dioxide, into the material through the radial, bottom, agitator sparge arms. Preferably drying operations are performed under reduced pressure e.g. the sparge gas or vapor is fed at approximately 500 Torr and the chambers are maintained at approximately 100-200 Torr by use of a vacuum pumping device. The chambers (G1-G5) may be arranged in a linear or circular configuration, and movement of solids through the chambers is promoted by the partial fluidization in the regions near the bottom sparge arms.