roller mill. horizontal waste laboratory. Rotational speed: 348, 360, 428, 270 rpm. Motor power: 1 kW. Machine length: 610, 660, 762, 927, 1,676 mm. The material to be milled is placed between the feed and center rolls. Each adjacent roll rotates at progressively higher speeds. For example; the feed roll may rotate at 30 rpm, the center roll at ...Web