PROCESS ENGINEERING SYSTEMS CONSISTING OF PNEUMATIC MACHINES FOR BLENDING, CONVEYING, AND SEPARATING PULVERULENT MATERIALS; MACHINES FOR RECOVERING HEAT FROM PULVERULENT MATERIALS; MACHINES FOR COMBUSTING PULVERULENT MATERIALS; CRUSHING AND GRINDING MACHINES FOR PRODUCING PULVERULENT MATERIALS; AND AIR SEPARATING, COOLING, AND HEAT TREATING MACHINES FOR SOLD AS A UNIT PROCESSING PULVERULENT MATERIALS; AND VALVES FOR CONTROLLING THE FLOW OF GASES IN INDUSTRIAL PROCESSING MACHINES