Abstract:
The invention relates to a device for effecting the automatic imbalance compensation of the rotor (5) of a centrifuge. The inventive device comprises a compensating ring (8) which, via an elastic bearing device (9), can be concentrically mounted in an inoperative position on a concentric surface of the rotor. The invention is characterized in that the bearing device is designed as an at least radially non-rigid elastic ring.
Abstract:
A method of controlling the evaporation of liquid in samples in an evaporating centrifuge, by monitoring the centrifugal force exerted on a sample holder containing a liquid sample having solid material dissolved or otherwise mixed therein. The centrifugal force is determined using a load cell (19), a strain gauge or, where relative movement between sample holder (4) and rotor (54) is permitted albeit with resilient restraining means, the centrifugal force signal may be generated by a position sensing transducer. The speed of rotation is sensed by a further transducer and both force and speed signals are conveyed to a computing means (54) programmed to generate a process control signal for controlling the evaporation process therefrom. A preferred method of control involves determining the rate of change of weight with time and terminating the evaporation process when the rate of change drops to zero. Evaporation is assisted by heating the samples and the process control signals determine not only the speed of rotation, but also the heating of the samples. A weight signal can be computed from the force signal by reference to the speed signal which is proportional to the centrifugal force acting on the sample holder and therefore the sample. A signal indicative of the weight of the sample itself can be computed by deducting from the combined weight of the holder and sample, a signal representing the weight of the sample holder itself. Different liquids evaporate at different rates and imbalance can occur as between different samples located around a rotor. Imbalance forces caused by differential evaporation rates may be reduced by means of a raceway (22) mounted on the rotor, or spindle driving rotor, which is incompletely filled with ball bearings (24) which in rotation distribute themselves around the raceway to counteract the imbalance forces.
Abstract:
A rotor (10) for use in a centrifuge includes a rotor body (12), a drive hub (20), and a balance ring (16, 160). The rotor body (12) includes an elongated bore (32) extending along its axis of rotation (24), and an upper surface (26) having an annular groove (42). The drive hub (20) is mounted within the elongated bore (32), and includes a drive portion (138) having a cross-sectional shape that is complementary to the cross-sectional shape of the elongated bore (32). The drive hub (20) applies torque to the rotor body (12) via engagement of the drive portion (138) with the lower bore opening (36) of the rotor body (12). The balance ring (16, 160) is positioned in the annular groove (42), and includes a plurality of apertures (78, 163) formed in an upper surface (90, 170) thereof. Each of the apertures (78, 163) is configured to receive a weight (80, 164) so that the rotor (10) can be balanced by selectively adding weights (80, 164) to one or more of the apertures (78, 163).
Abstract:
Rotor (10) einer Dualen Zentrifuge, der um eine Antriebsachse (A) in einer Zentrifuge drehbar ist, mit zueinander symmetrisch angeordneter Dreheinheiten (26), die ein Lager (32) und einen damit verbundenen, in diesem über eine Rotationsachse (Rl, R2) drehbar gelagerten Drehkopf (30) aufweist, wobei der Drehkopf (30) relativ zum Rotor von einem weiteren Drehmechanismus (46) der Zentrifuge um die Rotationsachse (R1, R2) antreibbar ist und eine Drehkopfaufnahme (80) für zumindest einen Probenbehälter oder Probenbehälteraufnahme (100, 110) aufweist, die Rotationsachse (R1, R2) des Drehkopfes (30) zur Antriebsachse (A) des Rotors schräg ausgerichtet ist, die Drehkopfaufnahme (80) für die Aufnahme einer länglichen Probenbehälteraufnahme (100, 110) oder eines länglichen Probenbehälters ausgebildet ist, die Längsachse der in die Drehkopfaufnahme (80) eingebrachte Probenbehälteraufnahme (100, 110) oder die Längsachse des in die Drehkopfaufnahme (80) eingebrachten Probenbehälters zwischen größer 0° bis unter 90° zur Rotationsachse (R1, R2) ausgerichtet ist. Zumindest ein Verbindungsbereich (52) ist vorgesehen, an dem zumindest eine Dämpfungsmasse (54) lösbar und über eine Fixierung fest anbringbar ist.
Abstract:
A centrifugal separator (1) for separating a fluid mixture into components, comprising a non-rotating part (2, 3), a rotor (5) which is attached to a shaft (6) which is rotatably supported in the non-rotating part (2, 3) around a rotational axis (x), which rotor forms within itself a separation space (8) delimited by a rotor wall (7). The separator comprises an inlet (8) extending into the rotor (5) for supply of a fluid mixture to be separated in the separation space (8), at least one sensor measuring unbalance conditions in the frame; a level determining arrangement comprising two or more space defining elements (16, 17) of arbitrary form arranged on the interior surface of, or close to, the rotor wall (7), where each space defining element (16, 17) defines a space which communicates with the separation space (8) or another of said space defining elements through at least one inlet opening (20) arranged at a certain radius (a, b) from the rotational axis (x) and not outside that radius and where that certain radii (a, b) of the space defining elements (16, 17) are different. Methods for determining when a predetermined amount of heavy phase fluid (purification) or sludge (clarification) has been separated. The aim of the invention is to provide separator and methods with which it is possible to determine when the level of separated heavy phase fluid or sludge is high enough for emptying or discharge of the separator.
Abstract:
L'invention concerne un procédé de contrôle de la vitesse de rotation d'un arbre vertical 11 d'une centrifugeuse. Un module de contrôle commande la vitesse de rotation de l'arbre et reçoit d'un capteur 37 des signaux sur le niveau des vibrations mesurées au sein de la centrifugeuse. Dans un premier temps, la rotation de l'arbre est accélérée jusqu'à une première vitesse déterminée NI inférieure à une vitesse de consigne, puis est décélérée jusqu'à une seconde vitesse déterminée N2. Le module de contrôle détermine le niveau maximum de vibrations au cours de l'accélération et de décélération. Si le niveau de vibrations n'a pas dépassé un certain seuil alors le cycle de centrifugation pour atteindre la vitesse de consigne est lancé. Selon un perfectionnement, au moins une masse compensatrice 13, 15 se positionne au cours de l'accélération pour limiter le déséquilibre des pièces solidaires de l'arbre 11. L'invention concerne aussi la centrifugeuse et le programme de contrôle associés.
Abstract:
L'invention concerne une centrifugeuse comprenant un arbre vertical (11) animé en rotation par un moteur, et un mécanisme d'équilibrage (32) des pièces solidaires dudit arbre vertical (11), ledit mécanisme comprenant : un plateau solidaire (10, 14) de l'arbre vertical, au moins une masse compensatrice (13, 15) se déplaçant librement sur ledit plateau (10, 14), ladite masse étant conçue pour limiter le déséquilibre des pièces solidaires de l'arbre vertical (11), et un mécanisme de blocage de ladite masse compensatrice, ledit mécanisme de blocage étant conçu pour immobiliser ladite masse compensatrice (13, 15) sur ledit plateau lorsque la vitesse de rotation dépasse une valeur déterminée.
Abstract:
A centrifuge to which sample tubes can be introduced while the centrifuge is in motion. The centrifuge comprises a carousel (202) having an upper portion (204) and a lower portion (206). The upper portion of the carousel has a plurality of positions for sample tubes for a centrifugation operation, a plurality of drive mechanisms (230) attached to the upper portion of the carousel, a movable element (352) mounted upon each drive mechanism, the movable element capable of traversing the length of the drive mechanism when the drive mechanism is actuated, a sample tube-holding assembly (258) comprising a sample tube holder (260) and a bearing (262) attached to each movable element, and at least one balancing element (320, 322) capable of contributing to a force vector that cancels an imbalance vector generated by rotation of the centrifuge.
Abstract:
An impeller for a centrifugal pump that includes a disk-shaped shroud having a central axis, a front surface, a rear surface, and a circular perimeter, and a hub at the center of the shroud, the hub having an axial bore. The impeller further includes a first set of vanes on the front surface of the shroud, the first set of vanes extending radially inward from the perimeter towards the hub, a second set of vanes on the rear surface of the shroud, the second set of vanes extending radially inward from the perimeter towards the hub, a balancing area on the rear surface of the shroud, the balancing area extending radially outward from the hub, and a number of openings in the shroud, the number of openings configured to allow a fluid to pass from one side of the shroud to the other.