Pneumatic Pumps and Rams for Extrusion
Pneumatic pumps for extrusion use a compressed air motor that moves the piston vertically from top to bottom and viceversa. The product is suctioned by the lower pump and carried to the outlet. The structure of the “pump unit” (suction valve, pump piston, material seal gaskets) allows both the material and piston to be supplied in both the ascending and descending phases.
The flow rate of a pneumatic pump depends on the quantity of material that it releases during each cycle and on the number of cycles that it completes (The cycle is the full stroke of the piston in both directions). Pneumatic extrusion pumps are divorced: the pneumatic motor is separated from the pump and the fluid is not in contact with the motor. In this type of transfer pump, the suction valve is not ball-shaped but that rather has a small plate that allows the user to pump very viscous materials (up to 2 million cps).
Generally these pumps are mounted on pneumatic rams that allow for the product to be suctioned directly by the drum and that allow for quick replacement of the drum itself. A pressing disc, fixed to the base of the pump, compresses the material eliminating the phenomenon of cavitation, ensures a constant flow of product and protects the materials that has not yet been pumped from contact with dust, humidity, and from drying-out caused by contact with air.