HEAT EXCHANGE OF DYNAMIC POWDER BEDS WITH A HEAT-TRANSFER SURFACE. I. A HELICAL SCREW CONVEYER AND A HORIZONTAL ROTATING CYLINDER D. S. Pashkevich , Yu. I. Alekseev , A. A. Moiseenko , and S. M. Radchenko UDC 536.241:66.021.4 Heat exchange of dynamic (mixing) beds of powders with heat-transfer surfaces in a tube with a helical conveyer and in a rotating smooth horizontal cylinder is studied by experimental methods. The heat-transfer coefficients as functions of the regime of powder motion are obtained. JEPTER74920199912 JEPTER7492012