Abstract: For separating and drying pellets from a suspension, centrifugal dryers have proved successful wherein a rotor equipped with conveyor blades and disposed vertically in an outside housing for collecting the liquid is enclosed coaxially by a hollow body formed of screen elements. The suspension of pellets and liquid is supplied continuously to the lower area of the space between the hollow body and the rotor. The pellets are transported upward by the conveyor blades rotating with the rotor while being thrown back and forth and dried between the conveyor blades and the screens. At the upper end of the rotor the dried pellets are thrown off. The liquid separated from the pellets passes through the screen jacket and flows out of the discharge port of the outside housing.

Abstract: For separating and drying pellets from a suspension, centrifugal dryers have proved successful wherein a rotor equipped with conveyor blades and disposed vertically in an outside housing for collecting the liquid is enclosed coaxially by a hollow body formed of screen elements.

Abstract: A nonreturn valve connected to a passage venting a gas-containing part of the filtrate collection chamber is located in a centrifuge drum base is operated as a siphon to increase the pressure differential, thus filtration rate, across the centrifuge filter or alternatively a system of rotatable siphon cups connected to the chamber are provided so that gas collecting in the collection chamber during filtration may be evacuated of the centrifuge. This device can also be used in the discontinuously operating filter centrifuge with a rotating siphon whose housing interior is at the pressure of the surroundings or is acted on with a gas pressure for additional acceleration of the filtration.

Abstract: A centrifuge apparatus and a method of filtration are described. The centrifuge has radial and lateral filtration surfaces and separate discharge chambers for each. The lateral filter is located at an imperforate radial distance from the radial filter. This distance forces the filtration to occur through the radial filter and develop the filter cake rather than pass through the lateral filter which has no developed cake. The use of separate, laterally-disposed withdrawal chambers at different radial heights allows accurate control over the hydraulic filtration forces acting across the filter surfaces.

Abstract: Agitator elements are provided in an apparatus and a process for the transport of heat and material between finely grained solid particles and a flow of carrier gas in a rotating fluid bed in order to prevent settling of coarse particles or agglomerates. The agitator elements are immersed into the fluid bed and move at a velocity different from that of the revolving fluid bed.

Abstract: A pocket centrifuge has a plurality of sieve pockets having sieve surfaces and orbitable about an axis with the sieve surfaces forming sieve angles with perpendiculars to planes including this axis. A filtrant is fed radially to these pockets so that solids collect on the surfaces thereof and a filtrate passes through the surfaces. These solids have a friction angle measured to a perpendicular to the centrifugal force acting on them which is dependent on the magnitude of this force and their coefficient of friction. The angular orbiting speed of the pocket is periodically varied between one speed at which the respective friction angle of the solids is smaller than the sieve angle and the solids slide on the sieve surface and another angle at which the respective friction angle of the solids is greater than the sieve angle and the solids sit on the sieve surface.

Abstract: A method of operating a particle-treating apparatus having a hollow foraminous drum centered on and rotatable about an upright axis comprises the steps of feeding particles into the upper portion of the interior of the drum, rotating the drum about the axis at a speed sufficient to form the particles into an annular body lying on the inner surface of the drum, passing a drying gas radially inward through the drum into the interior thereof and withdrawing the gas axially from the interior to at least partially fluidize the body and dry the particles, and collecting the particles beneath the drum as the body moves off the lower edge thereof. The rate of gas flow through the drum and the rotation rate of the drum are such that the body moves axially down in the interior toward the lower edge of the drum.

Abstract: A centrifugal filter has a centrifuge drum rotatable about an axis and provided with a plurality of sieve support plates lining the drum. Each of the plates is generally flat and rectangular and has a radially inwardly directed inner face. They are each formed with an array of flow grooves extending on and opening radially inwardly at the inner face and each having an outer end and an inner end spaced along the plate therefrom. The flow grooves are of increasing flow cross section from their outer ends to their inner ends. An outlet serves for draining liquid from the inner ends. A filter medium overlies the inner face over the flow grooves. Thus flow is maintained substantially uniform even at the outer groove ends, where relatively little filtrate moves. As a result clogging of these flow grooves is impossible; they will stay clear along their entire lengths.

Abstract: A process for the dewatering and particle classification of solids from suspensions, e.g. coal from a slurry in which the coal is transported, makes use of a dewatering centrifuge having two frustoconical centrifuge drum sections of different inclinations such that in a first filtering zone the particles are preliminarily dewatered and then pass by automigration to the next centrifuge drum at which further dewatering takes place. The suspension on the first sieve surface forms a thin layer classification zone having a thickness up to 5 mm and in which the coarse fraction is retained while the fine fraction is passed. The coarse fraction automigrates to the next sieve surface where it is dewatered and the fine fraction separated out in the thin layer classifying zone is then filtered under pressure in a subsequent stage.

Abstract: A centrifuge filter has a sieve drum normally rotated about its axis and normally fed internally with a filtrand that is separated when the drum rotates into solids lying on the inner surface of the drum and a filtrate that passes radially outwardly through the drum. A pusher plate is axially displaceable in the drum and has an outer edge closely juxtaposed with the drum's inner surface so that it can scrape solids from the surface. A cylinder is rotationally fixed to the drum and has a cylinder chamber that is axially subdivided by a piston into a front compartment and a rear compartment. This piston is jointly axially displaceable with the pusher plate and is axially biased backward. A liquid is introduced into one compartment to fill it as it rotates so that the liquid will be forced radially outward by centrifugal force and will urge the piston axially forward. This liquid is periodically drained off so that the force it exerts is less than that of the biasing means.

Abstract: A pocket-type centrifuge for processing sugar-beet or cane-sugar mash has a rotor which carries an annular array of pockets whose inner portions are formed as sieves and whose outer portions are constructed to mix a wash liquid with the mash that is fed axially into the rotor and that passes radially out over the pockets. A primary filtrate can be extracted from behind the sieves of the inner portions of the pockets, and the remainder of the mash mixture is then mixed with a wash liquid fed into an annular inwardly open chamber above the rotor that feeds its liquid into the outer portions of the pockets. From the pockets the mixed wash liquid and mash is projected onto a downwardly flared skirt of the rotor, and from this skirt onto an upwardly flared outer drum that is rotated slower than the rotor.

Abstract: A wobble centrifuge has a housing in which a tube shaft is rotatable about a first axis, this tube shaft having a lower tube part centered on the first axis and an upper tube part centered on a second axis that crosses the first axis at an intersection. An at least partially flexible core shaft has a lower core part rotatable in the lower tube part about the first axis and an upper core part rotatable in the upper tube part about the second axis. A downwardly flared sieve drum is carried on the upper core part and is centered generally on the second axis, this sieve drum having a wall tapered upwardly from a lower edge spaced below the intersection in a direction parallel to the second axis by a predetermined distance. A suspension to be centrifuged is introduced into the drum generally radially of the axes at a location spaced above the intersection in a direction parallel to the second axis by a spacing equal to substantially more than the spacing between the lower end of the drum and the intersection.

Abstract: A centrifuge has a drum to which a wobble or nutating motion is applied to discharge the centrifuged material over the edge of a wall of the perforated basket. The wobble or nutation is caused by tilting the axis of this wall relative to the axis rotation of the assembly. According to the invention, the basket is rotatably driven by an inner shaft and ride upon an inclined member driven by an outer shaft. The ratio n.sub.2 /n.sub.1 of the rotating speed n.sub.1 of the inner shaft and the rotating speed n.sub.2 of the outer shaft can be varied between values of -5 and +7 preferably -5 to +6 excluding values of about 0, 0.9, 1 and 2. The ratio determines the effective nutating angle.

Abstract: Particles to be dried are loaded into the bottom of an upwardly open vessel which is then spun about a central axis at a speed sufficient to form the particles into an annular body and to urge the particles radially outwardly with a centrifugal force greater than the force of gravity. The outer wall of the vessel is gas-pervious and drying gas is passed radially inwardly through this wall to contact the particles and at least partially fluidize the body of particles. The dried particles are drawn off out of the upper end of the rotating vessel as fresh wet particles are loaded into the lower end.

Abstract: A centrifuge for the separation of solids from liquids has a centrifuge drum rotatable about a substantially horizontal axis and formed, in addition to the filtering periphery, with a perforated ring annular disk transverse to this periphery for increased separation of liquid. The filtering ring, which lies inwardly of the perforated shell of the centrifuge advantageously opens toward an annular trough having the same radius as the ring or a greater radius. The trough is provided with a scoop or other emptying device to permit the radial position of the liquid level therein to be adjusted and/or to permit discharge of the trough.

Abstract: A method of operating a filter centrifuge or centrifugal filter in which a hydrostatic head is provided at the filtering surface so as to control liquid passage therethrough. The head may promote movement of the liquid through the filter layer or may induce reverse flow of liquid for backwashing or rinsing. In addition, a hydrostatic balance may be provided at this surface through control of the head to limit passage of the liquid through the filter layer. Preferably the head provides a suction augmenting centrifugal filtration.

Abstract: A method of operating a filter centrifuge or centrifugal filter in which a hydrostatic head is provided at the filtering surface so as to control liquid passage therethrough. The head may promote movement of the liquid through the filter layer or may induce reverse flow of liquid for backwashing or rinsing. In addition, a hydrostatic balance may be provided at this surface through control of the head to limit passage of the liquid through the filter layer. Preferably the head provides a suction augmenting centrifugal filtration.