International technology group GEA in February this year announced the launch of its new range of large inlet rotary valves for food and dairy powder products, which are designed specifically for applications that require an uninterrupted powder flow through the valve.
The design angle of the throat of the valve inlet is critical in these applications as any interruption to the flow can cause bridging, especially when handling products that do not flow well, such spray dryer, cyclone, and dust collection or recovery system applications where throughput is not the deciding factor but fine products that can bridge and restrict flow.
Stainless steel rotary valves have a suitably large inlet size for attaching to dryers and cyclones require a high structural integrity of the finished casting after machining. This can be difficult to achieve without adding unsightly external bracing, which can detract from the overall appearance of the finished valve and hinder its cleaning and maintenance.
GEA has solved this problem by manufacturing a much more rigid single-piece casting, which looks more aesthetically pleasing in a high hygiene food plant and performs much better under potentially dust explosion conditions. The high-quality castings have been designed in accord- ance with ATEX 94/9 CE Class 2 Cat1 Zone 20 to withstand dust explosions, making them ideal in high-risk installations such as spray dryers, cyclones and dust collection systems.
The heavier wall thickness of the GEA stainless steel castings makes sure that the valve body is rigid and will not flex under the most demanding conditions. This inherent rigidity further reduces the risk of flexing and the possible contact between the rotor and the body, which can result in contamination of the product.
The new valves are available in sizes ranging from 200 mm to 300 mm diameter for the CV500 model and from 300 mm to 350 mm for the CV750 model.