Patent ID: 6161956
Filing Date: 2000-12-19
Classification: B01F,B29B,F04B

Abstract:
A process for continuous, synchronous conveying of flowable materials by first and second conveyor pumps into a mixing device, from which the mixture of these materials feeds to an application device, whereby the first and second conveyor pumps are operated by respective first and second hydraulic adjusting units, in which first and second operating pistons are guided in respective first and second operating cylinders, and whereby the adjusting units lie in a hydraulic circuit of a drive fluid loading the operating pistons, whereby the first operating piston is driven to move back and forth in the first adjusting unit by a drive motor, and an essentially constant operating volume of the drive fluid is provided in the hydraulic circuit, wherein strokes of the first and second operating pistons are each measured by first and second position sensors arranged on the first and second operating cylinders, and measuring signals obtained by the position sensors are fed into a control device for controlling a constant mixture ratio of the flowable materials, a difference of the respective measuring signals from the first and second adjusting units being compared in the control device as an instantaneous actual value with an associated desired value, and from the difference of the actual and desired values an operating signal for the mass flow of the drive fluid is formed, and return points for back and forth movement of the operating pistons are selected approximately simultaneously with a drive motor return point of the movement in the drive motor.