Pelletron unveils its new rotary valves for pneumatic conveying systems for polymer pellets
Saving energy and market demands were the underlying factors for the development of a low-leakage rotary valve series for pneumatic pressure conveying for plastic resins. Design principle changes were implemented to every aspect of the valve to accomplish this task. These changes include a redesigned valve housing to optimize venting, an increase in the number of rotor vanes and expanded rotor vane tips. Expanded vanes at the ends result in lower air leakage. The rotor is manufactured in cast stainless steel, installed on a strong stainless steel shaft. A patent is pending for this new technology and unique design. In combination with the special rotor design, the number of rotor blades could be increased as well, which also contributes to a lower leakage rate. More vanes also provide more pockets, and result in an improved continuous product flow at higher filling rates. In addition, the air vent was completely redesigned for optimized venting of the leakage air. Because of the heavy duty structural rotor design, the clearance of the rotor in the housing could be reduced to a minimum. The integrated roof in the housing reduces the chopping of pellets to a minimum. The new rotary valves are available for various pressure applications, from a medium differential pressure of 1.5 bar, to a high pressure version for 3.5 bar. The valves are available for conveying capacities of ~2t/h up to ~100t/h, depending on the bulk density of the conveyed resins.