Abstract: In measuring the turbidity of a liquid, especially for determining water clarity in a water purification process in which after the addition of flocculant the water is centrifuged, light is emitted as a diffuse beam from a light source and the intensity of light reflected from gas bubbles in the liquid is detected by a photosensor. The light source and photosensor are incorporated in a probe having transparent cylindrical wall. The probe is sealed within a housing confining a liquid receiving chamber. A plurality of seals are provided forming a space containing a cleaning solution. An actuator is coupled to the probe for reciprocating the probe relative to the housing and seals for cleaning deposits from the wall.

Abstract: The conveyor of a decanter centrifuge includes a small outside diameter central hub extending for at least a portion of the longitudinal length. On the hub is attached a series of longitudinally- and radially-extending shaped ribs, which in turn attach to larger ribs that transverse an open feed zone. The longitudinal and transversing ribs support a ribbon conveyor flight. The open feed zone serves to decrease feed solids degradation. The ribs outside the feed zone serve to improve interface stability and minimize washout. The overall structure of the conveyor is mechanically stiffer and less prone to vibration. The conveyor is lighter and less expensive to construct.

Abstract: A decanter centrifuge is provided with a dual motor drive for purposes of start-up and efficient operation. The two motors are coupled together during, at least, the start-up of the centrifuge rotation so as to provide the desired power requirements and to reduce the thermal load on the motors. After reaching operational speed, a first motor continues to drive the centrifuge at the desired operational speed and the second motor may be disengaged from operation. The dual motor drive may be varied by use of wye-start and delta-run phase connections for the motors. The operating conditions of the two motors can be varied to provide the necessary power while maximizing efficiency of the operation.

Abstract: A decanter centrifuge including a discontinuous screw conveyor having flights only within the generally cylindrical portion of the centrifuge bowl. A restricting disc is provided adjacent to the heavy phase material discharge ports such that the restriction contacts the build-up of heavy phase within the portion of the bowl where the flights are discontinuous.

Abstract: A decanter centrifuge having an inflatable dam for controlling the pond level. Inflation of an annular bladder adjacent to the liquid discharge opening controls the radial height of the pond surface within the bowl of the centrifuge.

Abstract: A decanter centrifuge includes a control system for receiving input AC power and outputting a variable voltage and frequency for controlling the speed of the backdrive and the main drive motor. The control system includes a first controller for converting AC power into DC power and then converting the DC power to AC power at a variable voltage and frequency to the main drive motor. A second controller is connected to the first conversion unit through a common DC bus. The second controller converts DC power to AC power and supplies AC power at a variable frequency to the backdrive motor. The braking force created by the backdrive motor during operation of the decanter centrifuge creates electricity which is passed through the second controller and through the common DC bus to the first controller. Thus, the generated power from the backdrive motor is converted into power for use by the main drive motor.