Carl Schenck Ag

Gerhard Jost

Hans Werner

A method for taring a dosing belt weigher uses a weight signal produced by a load cell and a belt revolution signal produced by a sensor for providing a taring or weight correction signal that is processed in a taring unit. The taring unit ascertains the weight or load signal individually for each belt section and for a statistically relevant number of belt revolutions. Individual mean values are formed for the individual belt sections and these individual mean values are compared with the total mean value of the ascertained gross weight signals. The resulting difference values are used as taring signals for correcting the individual belt influences which are correlated locally to each individual belt section during the following belt revolution. Thus, each belt revolution is corrected with due regard to the values gathered in a substantial number of preceding belt revolutions.

Method for correcting and taring an output of a dosing belt weigher

In a method and system for controlling a differential dosing scale having a weighing device and a control for the delivery rate especially of loose bulk material achieved by comparison of rated and actual weight values, measures are taken to eliminate the effects of disturbances of the output signal of the weighing device. Improvements are achieved in that an estimated or predicted value (G) for the next measured weight value is derived from previously measured values (G.sub.i) of the output signal (G) of the weighing device. The predicted value (G) is compared with the next actual measured value (G.sub.i) to determine a difference. If this difference exceeds a prescribed tolerance range or value, the control of the delivery rate continues at the unchanged previous actual value (P) of the delivery rate. Thus, the effects of disturbances are greatly reduced or even completely eliminated. Changes in the rated value of the delivery rate can also be taken into account. A differential dosing scale for carrying out the method includes appropriate hardware components or software for achieving the described control.

Method and system for controlling a differential dosing scale

The quantity of a flow of bulk material passing over a measuring wheel is continuously measured by measuring the load r.p.m. of the wheel or of a motor driving the wheel and the power output torque of the motor. The resulting r.p.m. and torque values are used for calculating the quantity. Interfering influences are substantially eliminated by using a correction value in the calculation. The correction value is based on the inertia moment of all rotating components of the system and on variations in the load r.p.m. Load r.p.m. and power output torque measuring devices provide data to a microprocessor for the calculations for achieving a high measuring precision even when the r.p.m. varies.

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Muehltal, Germany

Gerhard Jost