Small Business Innovation Research/Small Business Tech Transfer
Centrifugal Sieve for Size-Segregation/ Beneficiation of Regolith
Project Description
Utilizing centrifugal force as the primary body-force, combined with both shearing flow and vibratory motion the proposed centrifugal-sieve separators can provide efficient gravity-level-independent size classification of granular feedstock like lunar regolith. Standard size separation methods for dry materials often depend on gravity as the primary body force. For separation of small sizes, gravity-force is usually supplemented with vibration and shearing flow. Granular materials naturally stratify during shear-flow with larger particles rising to the top. Depending on frequency and intensity, vibrations alone can induce large particles to rise to the top in a granular bed, independent of shear flow. The proposed centrifugal size-separators utilize the natural size stratification of flowing granular solids. They will function equally well under reduced gravity conditions and in vacuum. The nominal design is a configuration with only one moving part and no blades, or other high-wear components. Shearing flow and vibrations combined with a size-separating screen at the outside (or 'bottom') of the flow will separate particles, with the fines passing through the outer wall screen, and the coarse material passing axially through the continuous feed system. Multiple size separation streams are possible. Alternate designs with shear-enhancing blades, 'above' or inside the screen, will also be evaluated. Various approaches for screen deblinding, and other robustness enhancements, are part of the proposed designs. With appropriate selection of passing-screen size, and deblinding enhancements, the centrifugal-sieves could be used for regolith processor feedstock conditioning to remove material > 0.5cm diameter, and with alternate settings and screen size, also used for a degree of beneficiation, to select particular size ranges that have the highest percentage of desired mineral content. The centrifugal-sieve concept can be scaled to any desired mass flow rate.
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Anticipated Benefits
Size classification is utilized throughout the mineral, chemical and pharmaceutical industries. Improved methods to achieve size separation, especially gentle methods suitable for friable materials, could have wide applications. Granular solids are an integral part of the multi-billion dollar fundamental chemicals and agriculture industries. Size segregation is a small but important aspect of the fundamental materials industries. A portion of the size-separation currently done with vibrating screens and gravity, could be replaced by the proposed method, and even a small slice of the solids separations business could be significant economically for a startup company.
Reliable, robust separation methods that operate independent of gravity level would be useful for granular materials size separation for regolith processor feedstock conditioning. For example, the proposed centrifugal-sieve could remove regolith particles > 0.5 cm diameter before dumping the material into a storage bin during excavation operations for oxygen extraction. The proposed centrifuging sieve could also be used for a degree of mineral beneficiation to separate particles by size and thus, increase the concentration of particular minerals which are more prevalent in certain size fractions of bulk regolith. The proposed centrifugal-sieves can operate in low-gravity (1/6-g and 3/8-g) and micro-gravity as well as utilize multiple feedstock sources. The proposed separation concept can be tested in 1/6 g flight experiments and ground vacuum environments. The Discrete Element method (DEM) regolith flow simulation software that will be enhanced and utilized in the selection and evaluation of sieve designs will also be of value as a verified simulation tool for ISRU equipment design. More »
Reliable, robust separation methods that operate independent of gravity level would be useful for granular materials size separation for regolith processor feedstock conditioning. For example, the proposed centrifugal-sieve could remove regolith particles > 0.5 cm diameter before dumping the material into a storage bin during excavation operations for oxygen extraction. The proposed centrifuging sieve could also be used for a degree of mineral beneficiation to separate particles by size and thus, increase the concentration of particular minerals which are more prevalent in certain size fractions of bulk regolith. The proposed centrifugal-sieves can operate in low-gravity (1/6-g and 3/8-g) and micro-gravity as well as utilize multiple feedstock sources. The proposed separation concept can be tested in 1/6 g flight experiments and ground vacuum environments. The Discrete Element method (DEM) regolith flow simulation software that will be enhanced and utilized in the selection and evaluation of sieve designs will also be of value as a verified simulation tool for ISRU equipment design. More »
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Grainflow Dynamics, Inc. | Lead Organization | Industry | Livermore, California |
Glenn Research Center
(GRC)
|
Supporting Organization | NASA Center | Cleveland, Ohio |
Primary U.S. Work Locations
-
California
-
Ohio
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This is a historic project that was completed before the creation of TechPort on October 1, 2012. Available data has been included. This record may contain less data than currently active projects.