Abstract: A centrifugal separator recovers high specific gravity solids such as whole cells while at the same time enabling sedimentation of low specific gravity solids such as cell debris. The separator is provided with a dual zone separator liner with concentric separator shells or zones. Feed fluid is introduced into an inner shell. High specific gravity solids accumulate against the inner wall of the inner shell. Feed fluid flows into the coaxial outer shell where lower specific gravity solids accumulate on the inner wall of the outer shell under higher g-force relative to that within the inner shell for the same rotational speed. Feed fluid flows out an exit channel. Longitudinal, planar vanes are radially disposed between an outer shell inner wall and an inner shell outer wall. After centrifugation, feed fluid in the inner shell is drained, then accumulated solids are drained from the inner shell into an appropriate receptacle.

Abstract: A feed accelerator for a centrifugal separator includes a set of vanes or grooves built into its outer surface to define a plurality of channels. Channel openings at the bottom of the accelerator face in the direction of rotation, and the channels curve upwards, aligning with the rotation axis at the top of the accelerator, so as to accelerate the feed liquid from bottom to top of the accelerator. The entry and exit points of the channels are positioned within smoothening zones that promote a circumferentially homogeneous distribution of the feed material. The purpose of this device is to provide minimal shear forces on the channel entrances to minimize shear stress on the feed liquid which can contain fragile solids in suspension. It is intended to be used primarily in automatic piston discharge liquid/solid centrifugal separators.

Abstract: A centrifugal separator recovers high specific gravity solids such as whole cells while at the same time enabling sedimentation of low specific gravity solids such as cell debris. The separator is provided with a dual zone separator liner with concentric separator shells or zones. Feed fluid is introduced into an inner shell. High specific gravity solids accumulate against the inner wall of the inner shell. Feed fluid flows into the coaxial outer shell where lower specific gravity solids accumulate on the inner wall of the outer shell under higher g-force relative to that within the inner shell for the same rotational speed. Feed fluid flows out an exit channel. Longitudinal, planar vanes are radially disposed between an outer shell inner wall and an inner shell outer wall. After centrifugation, feed fluid in the inner shell is drained, then accumulated solids are drained from the inner shell into an appropriate receptacle.

Abstract: A hermetically sealed solids discharge centrifugal separator having a separator bowl with a cylindrical upper portion and a conical lower portion, an inlet port at the bottom of the bowl and an outlet port at the top of the bowl. A disposable liner assembly includes a bowl liner having a cylindrical upper portion and conical lower portion, such that the bowl liner can conform to the interior surface of the separator bowl. The liner assembly further includes a piston within the bowl liner, the piston having an upper portion that conforms to the bowl liner cylindrical upper portion and a lower portion that conforms to the bowl liner conical lower portion. A fluid pathway extends through the piston, with a shuttle valve disposed within the fluid pathway.

Abstract: A centrifugal separator includes a cylindrical bowl having a conical lower end with an opening through which feed liquid is injected during a feed mode of operation. During the feed mode, solids separate from the feed liquid and accumulate along the inner surface of the bowl as the bowl rotates at high speed. After accumulation of the solids, the rotation of the bowl is stopped and residual liquid is drained by gravity from the bowl. In a solids discharge mode of operation, a piston of a piston assembly is urged downward along a vertical axis in response to fluid such as compressed gas or hydraulic liquid. The downward movement of the piston forces accumulated solids from the bowl via the opening in the conical lower end thereof. The solids pass from the bowl and into a passage leading to an outlet port, where the solids exit the separator.

Abstract: A hermetically sealed solids discharge centrifugal separator exhibits low-shear filling, acceleration, and separation of feed material. The separator can be particularly useful for separation and recovery of sensitive solids such as chemical or biological substances. The separator accommodates disposable sample contacting elements to eliminate the need for clean-in-place and sterilize-in-place operations. Some embodiments of the separator feature dual solids discharge pistons, which fully optimize recovery of valuable solids.

Abstract: A centrifugal separator includes a cylindrical bowl having a conical lower end with an opening through which feed liquid is injected during a feed mode of operation. During the feed mode, solids separate from the feed liquid and accumulate along the inner surface of the bowl as the bowl rotates at high speed. After accumulation of the solids, the rotation of the bowl is stopped and residual liquid is drained by gravity from the bowl. In a solids discharge mode of operation, a piston of a piston assembly is urged downward along a vertical axis in response to fluid such as compressed gas or hydraulic liquid. The downward movement of the piston forces accumulated solids from the bowl via the opening in the conical lower end thereof. The solids pass from the bowl and into a passage leading to an outlet port, where the solids exit the separator.

Abstract: In a system for combined centrifugation and microfiltration, retentate from a cross-flow microfilter is fed to an automatic piston discharge centrifuge for solids removal, thereby enhancing the efficiency of both processes. The centrifuge includes a cylindrical bowl having a conical lower end with an opening through which feed liquid is injected. Solids separate from the feed liquid and accumulate along the inner surface of the bowl as the bowl rotates at high speed. A microfiltration membrane can be added to improve solids retention in the bowl and provide a filtered centrate. During solids discharge, a piston is urged downward along a vertical axis. The downward movement of the piston forces accumulated solids from the bowl via the opening in the conical lower end thereof.

Abstract: A centrifugal separator includes a cylindrical bowl having a conical lower end with an opening through which feed liquid is injected during a feed mode of operation. During the feed mode, solids separate from the feed liquid and accumulate along the inner surface of the bowl as the bowl rotates at high speed. After accumulation of the solids, the rotation of the bowl is stopped and residual liquid is drained by gravity from the bowl. In a solids discharge mode of operation, a piston of a piston assembly is urged downward along a vertical axis in response to fluid such as compressed gas or hydraulic liquid. The downward movement of the piston forces accumulated solids from the bowl via the opening in the conical lower end thereof. The solids pass from the bowl and into a passage leading to an outlet port, where the solids exit the separator.

Abstract: A centrifugal separator includes a cylindrical bowl having a conical lower end with an opening through which feed liquid is injected during a feed mode of operation. The feed liquid is separated into centrate and solids, which accumulate along the inner surface of the bowl. A piston assembly includes a conical piston disposed within the cylindrical bowl, coupled to a piston actuator by a two-part piston shaft. During the feed mode of operation, the piston shaft is disconnected, and the piston is held in an uppermost position by hydraulic pressure from the feed liquid as the bowl is rotated, and a centrate valve on the piston is opened to permit the centrate to flow out to a centrate discharge port. After solids are separated and accumulated on an interior surface of the bowl, the rotation of the bowl is stopped and residual centrate is drained therefrom.

Abstract: A centrifugal separator includes a cylindrical bowl having a conical lower end with an opening through which feed liquid is injected during a feed mode of operation. The feed liquid is separated into centrate and solids, which accumulate along the inner surface of the bowl. A piston assembly includes a conical piston coupled to a piston actuator by a two-part piston shaft. During the feed mode of operation, the piston shaft is disconnected, the piston is held in an uppermost position by hydraulic pressure from the feed liquid, and a centrate valve on the piston is urged open to permit the centrate to flow out to a centrate discharge port. In a solids discharge mode of operation, the piston shaft is connected and the piston actuator urges the piston axially downward, closing the centrate valve and forcing the accumulated solids from the bowl via the opening in the conical lower end of the bowl.

Abstract: A centrifugal separator provides for the discharge of solids by either an axial-motion scraper or a piston/extrusion assembly. The axial-motion scraper is used with hard-packed or friable solids, and includes an integral feed liquid accelerator and feed holes. The piston/extrusion assembly is used with pasty solids, and includes a piston extending into a separator bowl and having openings permitting fluid communication across the piston. After high-speed separation is complete, a centrate valve closes one end of the bowl, and the piston is moved axially in the bowl by an actuator. Accumulated solids are scraped from the sides of the bowl and extruded out of the piston openings for discharge from the bowl. A bowl suspension employs a spherical mounting structure and a short, stiff spindle. A spherical portion of a bearing housing is mounted in a spherical mounting region at one end of the separator, with a cylindrical portion of the bearing housing extending along the rotational axis.

Abstract: A centrifugal separator provides for discharge of solids by either an axial-motion scraper or a piston/extrusion assembly. The axial-motion scraper (80) is used with hard-packed or friable solids, and includes and integral feed liquid accelerator and feed holes. The piston/extrusion assembly is used with pasty solids, and includes a piston (12) extending into a bowl (10) and having openings (45) permitting fluid communication across the piston. After separation is complete, a centrate valve (34) closes one end of the bowl, and the piston is moved axially in the bowl by an actuator. A bowl suspension employs a spherical mounting structure (96) and a short spindle (98). A bearing (100) and the spindle (102) of the bowl are mounted within the bearing housing. The suspension is retained by a ring and retaining member secured to the separator in compressive contact with the spherical portion of the bearing housing.

Abstract: A centrifugal separator provides for automatic discharge of solids by either an axial-motion scraper or a piston/extrusion assembly. The axial-motion scraper is used with hard-packed or friable solids, and includes an integral feed liquid accelerator and feed holes. The piston/extrusion assembly is used with pasty solids, and includes a piston extending into a separator bowl and having openings permitting fluid communication across the piston. After high-speed separation is complete, a centrate valve closes one end of the bowl, and the piston is moved axially in the bowl by an actuator. Accumulated solids are scraped from the sides of the bowl and extruded out of the piston openings for discharge from the bowl. A bowl suspension employs a spherical mounting structure and a short, stiff spindle. A spherical portion of a bearing housing is mounted in a spherical mounting region at one end of the separator, with a cylindrical portion of the bearing housing extending along the rotational axis.

Abstract: A centrifugal separator includes a rotatable separator bowl, a hollow shaft spindle in the bowl along the rotational axis of the bowl, and a variable-drive motor for selectively rotating the bowl at a high separating speed and at a lower scraping speed. A scraper and feed assembly including scraper blades is supported by the shaft spindle within the separator bowl. A feed liquid is supplied to the separator bowl via the scraper and feed assembly at substantially the interior surface of the separator bowl. The scraper assembly rotates with the bowl at the separating speed while centrate is drawn off. While the bowl is operated at the scraping speed, the scraper assembly is prevented from rotating with the bowl and is moved axially with respect to the bowl to scrape accumulated solids from the interior surface of the bowl. Loosened solids exit the centrifuge via a discharge port at the bottom of the bowl.

Abstract: There is provided a centrifugal separator for solid-liquid separations. The centrifugal separator comprises (a) an accelerator rotatable at an angular velocity, &ohgr; about an axis, and having an inside surface with a point on the axis, and (b) a nozzle for introducing a feed stream at a volumetric flow rate (Q) into the accelerator via an orifice. The orifice is substantially centered about the point, and the orifice has an inner diameter (d) within the range of approximately 0<d≦4&dgr;, where &dgr;=1.414 [(4Q/&pgr;2&ohgr;)1/3].

Abstract: There is provided a centrifugal separator for solid-liquid separations. The centrifugal separator comprises (a) an accelerator rotatable at an angular velocity,&ohgr; about an axis, and having an inside surface with a point on the axis, and (b) a nozzle for introducing a feed stream at a volumetric flow rate (Q) into the accelerator via an orifice.

Abstract: A centrifugal separator is provided which maximizes solids recovery yield and separated solids dryness with minimal user intervention. The centrifugal separator includes a rotatable separator bowl, which is selectively rotatable and supported by a hollow shaft spindle. A scraper and feed assembly including a plurality of scraper blades is supported by the shaft spindle within the separator bowl. A feed liquid is supplied to the separator bowl from the scraper blades at substantially the interior surface of the separator bowl so that the feed liquid is gradually accelerated upon entering the separator bowl. High speed operation of the centrifugal separator is performed to generate separation forces as high as 30,000 g's at the interior surface of the separator bowl. This allows the feed liquid to be safely and effectively separated at lower stress levels within the separator bowl.

Abstract: A dry cleaning process and system for cleaning articles disposed in a cleaning chamber having a rotatable member therein, using carbon dioxide (CO2) from a storage tank. The process includes causing a pressure differential between the storage tank and the cleaning chamber, filling the cleaning chamber with a predetermined amount of liquid CO2 enabling flow of liquid CO2 from the storage tank to the cleaning chamber in response to the pressure differential, and rotating the rotatable member.

Abstract: A dry-cleaning process for cleaning articles disposed in a cleaning chamber having jet inflow ports, using carbon dioxide (CO2) from first and second storage tanks, the process including the steps of compressing gaseous CO2 into the first storage tank to cause a positive pressure differential between the first storage tank and the cleaning chamber, filling the cleaning chamber with liquid carbon dioxide by enabling CO2 flow from the first storage tank to the cleaning chamber in response to the positive pressure differential, alternately compressing gaseous CO2 into the first or second storage tanks to cause a pressure differential between the first and second storage tanks, and flowing liquid CO2 between the first and second storage tanks, via the jet ports and through the cleaning chamber, in response to the pressure differential between the first and second storage tanks, to provide jet agitation in the cleaning chamber and a periodically continuous flow of liquid CO2 through the cleaning chamber.