An improved version of the patented RotorCheck system for rotary valves from Coperion (U.S. office Ramsey, N.J.) relies on a monitoring device that detects any metallic contact between the rotor and the housing. This contact may result either from the presence of foreign particles or from a process malfunction, such as a sudden increase in product temperature, which may cause the rotor blades to expand and grate against the housing. Further causes may be a damaged bearing or incorrect installation or maintenance of the rotary valve.
In each scenario, RotorCheck not only prevents serious damage to the rotary valve itself but protects the product, which in most cases is conveyed by a pneumatic conveying system, against contamination by metallic particles (abraded metal).
Typical examples are the handling of polycarbonate pellets for the production of CDs, and the handling of insulating polymers for high-tension cables.