Abstract: A decanting type centrifuge comprising a bowl which rotates about a horizontal or vertical axis and contains a helical screw conveyor for separating a slurry fed to the bowl into its constituent solids and liquid, the scroll being arranged to rotate at a differential speed within the bowl and wherein at least some of the flights of the scroll conveyor are inclined backwards relative to the solids discharge end of the bowl.

Abstract: An apparatus which performs solids particles separation from a liquids/solids slurry, and subsequent drying of such solids particles, within a single enclosure. Further processing functions, such as reslurry washing, plug washing, crystal growth and other reactions, can also be carried out within that single enclosure.

Abstract: A centrifuge basket shell formed by winding fiber-reinforced resin tape in a helical pattern over a thin shell plate which contains a plurality of holes for the passage of liquid therethrough, perforations being formed in the helix pattern of the wound tape by means of respective hollow ferrules connected rigidly to a cylindrical part of the shell plate, so as to enable liquid which passes through said holes in the shell plate to pass also through the helices of wound tape without increasing the stresses induced therein by rotation.

Abstract: A centrifuge, for example a decanter type centrifuge, comprises a bowl (10) rotatable about a longitudinal rotational axis (Y), an inlet (14) for feeding into the bowl a slurry to be separated, and a helical scroll conveyor (12) rotatably mounted about the rotational axis and adapted to be rotated within the bowl at a different speed from that of the bowl in order to scroll particles adjacent to the bowl wall to a solids discharge end of the bowl. The decanter further comprises a plurality of walls (23) at least partly submerged in the centrate and defining passages therebetween. By providing a plurality of passages, through which the centrate to be clarified can travel, particles (e.g. solids) to be separated from the centrate have a short distance to travel under centrifugal force before entering the boundary layer at the walls of the passages. This enables more of the fine particles in the centrate to be separated out.

Abstract: A method and apparatus for testing, in situ, for imperfections in an inert coating of a moving metal component of an apparatus (e.g. a metal basket of a centrifuge) involves covering the inert coating with an electrically conductive liquid, applying an electrical voltage across the inert coating while the apparatus is operational, monitoring the current or applied voltage, and utilizing the measured current or voltge to provide an indication of the condition of the inert coating. If the coating is defective, the conductive liquid will find its way into any flaws or imperfections, thereby providing a path of lower electrical resistance.

Abstract: A method of separating solid particles from the liquid constituent of a slurry, containing solids having a "wide" particle size distribution, that is, a size distribution wherein the equivalent diameter of particles in the slurry ranges between at least 15 microns and 150 microns. The method uses a screen bowl centrifuge and comprises: (a) establishing a bed of solids on the screen section of the centrifuge whose maximum radial thickness is greater than 15 times the mean particle equivalent diameter of said solids in the slurry; (b) operating the scroll of the centrifuge at a speed within the range of 0.5 to 10% of the bowl speed; and (c) returning at least a portion of the solids contaminated centrate from the centrifuge to the interior of the screen section of the bowl so as to deposit the centrate on the solids passing over the screen section at or adjacent a region of maximum solids thickness.

Abstract: A decanting type centrifuge having a main bowl which is adapted to be rotated about its longitudinal axis and which contains a helical scroll conveyor which is arranged to rotate about the main bowl axis at a slightly different speed to the main bowl for scrolling separated solids to a solids discharge end of the bowl. The centrifuge includes a means which acts to isolate a gas volume radially inwardly of the inner liquid surface within the bowl and also a passage arrangement which enables gas to be extracted continuously from the isolated gas volume to a location external to the main bowl.

Abstract: In a disc bowl centrifuge, means are provided for introducing pressure fluid into a piston chamber serving to operate a discharge valve controlling outlet of processed material from the bowl, which means are such as to allow a pressure substantially higher than atmosphere and sufficient to hold the discharge valve closed against the opening forces exerted thereon by process material subjected to centrifugal force in the bowl.