(335e) A Low Pressure Vertical Lift System for Coarse Powders and Granular Solids

This paper outlines the construction, development and operation of a simple feeder inspired by the L-Valve. Non-mechanical seals are attractive in hygienic applications such as food processing because there are no wear surfaces, and the threat of contamination of the product by filings and other wear detritus is eliminated. The lifter is essentially comprised of a vertical tube attached to the central arm of a Tee; an elbow attached to one of the horizontal arms leads into a vertical downcomer which holds the feed material and another elbow attached to the other horizontal arm admits conveying air. Solids flow rate is controlled by aeration air admitted to a point on the centre-line of the Tee, at the base of the downcomer. This device is cheap to make and install, or to retrofit to existing installations, and has found widespread and continuing application in the food industry.