Abstract: A process and a device are used to process granulated materials such as abrasives for centrifugal wheel cleaning systems or welding powder for welding machines. Operation is based on the suction principle; an adjustable amount of ambient air is drawn in to be used as the conveying air for the granulated material and takes the latter to the processing device. A part of this conveying air is also used to separate foreign bodies from the granulated material. Granulated material and conveying air flow in a stream of material which gradually grows wider and thinner, to an accumulation point from which they trickle in the form of a screen to a hopper. In the process the other portion of conveying air flows through them. The ambient air that is drawn in may also be used to remove dust from an operating compartment before it is used as conveying air. Negative pressure prevails throughout the system to prevent particulate escape into the environment.