Rotary valves

Abstract From the Canadian patent

The invention provides for a rotary valve of the type employed for transporting solid material between zones having a fluid pressure differential, with a minimum fluid leakage between the zones. The valve comprises a housing having a bore passages communicating with the bore and designed to be coupled to the respective zones, and a rotor which is housed within the bore, the rotor defining an axial drive shaft a pair of spaced, end plates on the shaft and a series of radial vanes disposed between the end plates, the valve being characterised in the provision of material helically wound threads or grooves formed on the peripheral surfaces of the end plates which urge material trapped therein …