A rotating annular crossflow filter shears radially outward flowing axial feed between counter-rotating coaxial centrifugal impellers. A radial impedance of flow at the
impeller periphery slows the radially outward flow and increases
residence time of feed between the impellers. Shear lift ejects solids from the boundary layer at the filter surface, and ejected solids collect by
centrifugation at the
impeller periphery, where they thicken into a
sludge and are extruded. Gases, oils, floating solids, and fractions having a
specific gravity less than water evolve into radial vortices and are sucked radially inward and out from between the impellers by an axial pump. Three way phase separation proceeds continuously in
one pass through a simple mechanical device having a long
residence time for feed in the
processing zone.Opposing rugose portions of counter-rotating
impeller surfaces cause
audio frequency pressure pulses. At the impeller periphery, the pressure pulses milk liquid out of
sludge. At the portion of the radial passage prior to the filter, pressure pulses evolve gases and degassed
cavitation bubbles inactivate microbes. Degassing of the
high energy forced periodic
cavitation bubbles between the impellers removes the
cushion of noncondensibles which would otherwise absorb energy on compression, therefore implosion becomes extremely violent and a barrage of
high pressure pulses and
ultraviolet light pulses inactivates microbes.Applications include field water purification, municipal and industrial
wastewater degassing and
sludge thickening, swimming
pool filtration,
effluent dewatering,
wine and beverage degassing and clarification, fruit crushing,
olive oil dewatering, produced brine and drilling mud
processing,
manure slurry dewatering and degassing, and
recovery of solvents and fine
suspended solids from fluid mixtures such as
wastewater from
machining operations.