Most short-distance bulk material transport operations are potential applications for this new technology. Relatively rapid, yet gentle transport of solids is possible with appropriately designed screw-steps so that no abrupt velocity changes occur. In many situations this technology could replace conventional screw augers or dense-phase pneumatic transport lines. The centrifuging step-screw is particularly well suited for any situation where rapid, precise control of solids flow rate is desired. The range of industries utilizing granular solids is very broad, including the mining, agriculture, chemical and pharmaceutical fields. All of these industries have operations where the centrifuging step-screw could be utilized.
Almost all plans for extended lunar operations include the production of oxygen from lunar regolith, but even shorter missions will involve collection, moving, handling, and often processing of fine cohesive regolith powder. The excavation rate needed for O2 production is on the order of 50kg/hr and for Site preparation tasks up to 300 kg/hr would need to be excavated and moved. Total amounts of regolith required are 100 tons for O2 production and over 2,000 tons for a full outpost deployment. NASA needs hardware that is able to operate over broad temperature ranges (40 K to 400 K) and in the presence of abrasive lunar regolith and partial-gravity environments. Generally NASA needs lunar regolith handling hardware that is robust, lightweight, abrasion resistant, made from vacuum and large temperature variation compatible materials, and with low power, low maintenance, and has a minimum of dust generation during operation. The centrifuging step-screw conveyor developed under this project meets all of those requirements. The method can be scaled to any required capacity, moving loose granular material over distances up to 20m in any direction, at any inclination, independent of gravity, with precise flow control, easily meeting the stated Oxygen production requirement of a 2m elevation change for 50kg/hr.
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