A centrifuge (1) for separating intermixed particulate material of different specific gravity. The centrifuge (1) comprising a centrifuge bowl (10) having a plurality of annular recesses (19), a housing (30), an inlet (17), and means for rotating the centrifuge bowl (10) about the central axis (15). An annular cavity (31) is defined between the housing (30) and the centrifuge bowl (10). The annular cavity (31) is fluidly connected to the plurality of annular recesses (19) on the inner surface of the centrifuge bowl by a number of perforations in the centrifuge bowl wall (12). The annular cavity (19) has a fluid inlet to provide fluid into the annular cavity. The annular cavity (19) has an accumulated cross-sectional flow area (Allow) at two different heights in the annular cavity that differs by at least a factor 10.

A centrifuge (1) for separating intermixed particulate material of different specific gravity. The centrifuge (1) comprising a centrifuge bowl (10) having a plurality of annular recesses (19), a housing (30), an inlet (17), and means for rotating the centrifuge bowl (10) about the central axis (15). An annular cavity (31) is defined between the housing (30) and the centrifuge bowl (10). The annular cavity (31) is fluidly connected to the plurality of annular recesses (19) on the inner surface of the centrifuge bowl by a number of perforations in the centrifuge bowl wall (12). The annular cavity (19) has a fluid inlet to provide fluid into the annular cavity. The annular cavity (19) has an accumulated cross-sectional flow area (Allow) at two different heights in the annular cavity that differs by at least a factor 10.

An apparatus for facilitating particle separation by density includes a separator having an inner surface surrounding a rotation axis and defining a particle path from an input end to an axially spaced output end. The inner surface includes a plurality of axially spaced dividers having respective inner positions, defining at least in part respective axially spaced retainers for collecting particles during rotation of the separator. The retainers each include at least one fluid inlet for fluidizing particles in the retainer during operation. The dividers include a first pair of adjacent dividers and a second pair of adjacent dividers, the first pair nearer the input end than the second pair, wherein a first divider slope of the first pair is greater than a second divider slope of the second pair and wherein each of the first and second divider slopes is zero or positive. Other systems, apparatuses and methods are disclosed.

Provided is a centrifugal field-flow fractionation device capable of suppressing deformation of a channel member. Pressure in a channel formed inside the channel member in a centrifugal field-flow fractionation device 1 is increased by a pressure increasing mechanism 8 provided downstream of the centrifugal field-flow fractionation device 1. In this manner, an inner surface of the channel is pressed outward by a liquid sample in the channel, and an outer peripheral surface and an inner peripheral surface of the channel member can be suppressed from being recessed toward the channel side.

Provided is a centrifugal field-flow fractionation device capable of suppressing deformation of a channel member. Pressure in a channel formed inside the channel member in a centrifugal field-flow fractionation device 1 is increased by a pressure increasing mechanism 8 provided downstream of the centrifugal field-flow fractionation device 1. In this manner, an inner surface of the channel is pressed outward by a liquid sample in the channel, and an outer peripheral surface and an inner peripheral surface of the channel member can be suppressed from being recessed toward the channel side.

Particles are separated from a source viscoplastic fluid by flowing streams of the viscoplastic fluid and a destination fluid in parallel streamed relationship inside a rotating cylindrical annulus by using baffles to introduce each fluid independently at an inlet lower end of the annulus and for separating the upper streams consisting of an un-yielded source and destination flow proximate the radially innermost side of the annulus, a bulk axial flow in a more central region and a yielded layer destination flow adjacent the radial outermost side of the annulus which contains the particles that have separated. Inlet and outlet baffles are provided at each end of the vertically oriented device to maintain the flows discrete on entry and to maintain the separated flows discrete on exit so as to facilitate removal of the component flows from the fractionator.

Particles are separated from a source viscoplastic fluid by flowing streams of the viscoplastic fluid and a destination fluid in parallel streamed relationship inside a rotating cylindrical annulus by using baffles to introduce each fluid independently at an inlet lower end of the annulus and for separating the upper streams consisting of an un-yielded source and destination flow proximate the radially innermost side of the annulus, a bulk axial flow in a more central region and a yielded layer destination flow adjacent the radial outermost side of the annulus which contains the particles that have separated. Inlet and outlet baffles are provided at each end of the vertically oriented device to maintain the flows discrete on entry and to maintain the separated flows discrete on exit so as to facilitate removal of the component flows from the fractionator.

An apparatus for collection of heavier particles such as gold flowing in a river includes a support frame with legs for mounting in the river spaced from the bed with a series of drum mounted on the support frame one behind the other for rotation about an axis transverse to the river flow. The drums have a plurality of blades mounted so that flow of water in the river causes a rotation of the drum, a plurality of water entry openings and a plurality of discharge openings in the drum with the drum shaped such that rotation causes a centrifugal action such that the heavier particles remain within the drum against escape from the drum while lighter particles and water are discharged.

A compact and portable multi-stage centrifuge apparatus comprising a cart, a housing mounted onto the cart, and an engine mounted onto the cart adjacent to the housing, wherein the housing comprises an inlet in the top of the housing, an outlet in the wall of the housing, and a bowl contained within the housing, wherein the bowl comprises an engagement member that is operatively coupled to the engine's drive shaft, such that the bowl can be rotated by engaging the engine, thus removing undesirable materials from the bowl and out of the housing through the outlet.

A compact and portable multi-stage centrifuge apparatus comprising a cart, a housing mounted onto the cart, and an engine mounted onto the cart adjacent to the housing, wherein the housing comprises an inlet in the top of the housing, an outlet in the wall of the housing, and a bowl contained within the housing, wherein the bowl comprises an engagement member that is operatively coupled to the engine's drive shaft, such that the bowl can be rotated by engaging the engine, thus removing undesirable materials from the bowl and out of the housing through the outlet.