Abstract
A feeder screw supplied at constant pressure by a hopper-orifice arrangement was developed for feeding solids in size ranges up to several hundred micrometers at constant flow rates. Performance of the feeder was evaluated by measuring the flow rates obtained with 3- to 7-micrometer coal ash, 70 percent through 200-mesh coal, and minus 325- plus 400-mesh coal ash. Constant feed rates within a few percent of set values were achieved for half-hour periods for the larger particles and for 5 minute periods for the finer particles. Suggestions are given for feedstock preparation and feeder operation for optimum performance.
