Coperion Waeschle: High-pressure blow-through valve: More throughput, less investment
With the ZXQ series Coperion Waeschle GmbH & Co. KG, Weingarten, has developed the first high-pressure blow-through valves in the world for applications in the plastics and chemicals industry. These valves feed powders into pneumatic conveying systems and are suitable for differential pressures of up to 3.5 bar. The new ZXQ rotary valves achieve capacities which are 30 to 60 per cent higher than those reached by conventional valves of the same nominal size, depending on the product and the differential pressure. The reasons:
•The conveying air for product transport flows parallel to the rotary valve axle directly through the lower chambers of the rotor. This results in forced discharge which also ensures that the rotor chambers are fully emptied, even when cohesive powders are conveyed.
•The valve geometry is optimised, especially the ratio of the inlet cross-section to the rotor
volume, and all types of powder are easily fed into the large-dimensioned valve inlet.
This increase in capacity lowers the investment and operating costs of the ZXQ valves, as it is generally possible to install a smaller valve for a set throughput than was previously possible. In addition, the ZXQ valves do not require any rotor seal or locking gas piping in contrast to the discharge valves previously used for high pressures. This enhances functional reliability, lowers maintenance costs and means a further decrease in investment. With this design the inlet into the conveying line is no longer required, reducing the height of the blow-through valves. They are therefore suitable for retrofitting in existing conveying systems and are particularly advantageous if the conveying capacity of the system is to be increased by increasing the pressure.