Rotary valve 3D - An example of a DT valve
Rotary Valves have been traditionally manufactured by GEA Nu-Con for over 40 years for numerous applications involving dairy, food, pharmaceutical, nutritional products and other ingredients. From this experience GEA Nu-Con have developed an extensive range of both standard and customised options to meet specific requirements. Whether required for an air lock or metering duty there is a GEA Nu-Con rotary valve to suit all specifications.
Principle of Operation:
The prime function of a rotary valve is to regulate the flow from one chamber to another while maintaining a good airlock condition. The product is mainly in dry powder or granular form.
The “convey-through” rotary valve, which is used mainly for more cohesive or sticky powders (e.g. cocoa powder, flour, milk powder) that may not discharge properly from a drop-through rotary valve (i.e. fine powder compacts and sticks to the inside of the wedge-shaped rotor pockets).
Basically the valve is designed with a paddle wheel which is shaft-mounted and driven by a motor. The rotary valve is similar to a revolving door: the paddles or blades create a triangular pocket between blades and the circular housing that it is rotating in and form an airtight seal with the housing; the motor slowly moves the blades to allow the solids to discharge from the hopper.
The rotating shaft/paddle has vanes/blades that fill with product on one side of the valve as the empty pockets are rotated to present a space for material to flow in.
CV - Convey Through: Material enters at the top and discharges horizontally at 90 degrees to the inlet via a pneumatic convey line.
DT - Drop Through: Material enters at the top and discharges vertically from the bottom outlet.