Patent ID: 8052322
Filing Date: 2011-11-08
Classification: G05D

Abstract:
1. A process for control of a system for metering and mixing a product that consists of a first component and a second component to be mixed in a mixer at a predetermined metering ratio, and the system comprises: a first alternating pump that can inject said first component into the mixer, a second alternating pump that can inject said second component into said mixer sequentially relative to the first pump, whereby movement of a piston of each pump can be reversed from a direction of suction and expulsion of a corresponding first and second component to a direction of expulsion of the corresponding first and second component and vice versa, and an injection valve inserted between each pump and the mixer, the process comprising a first injection cycle of the following steps: Initiating a reversal of the piston of each pump in a direction of suction and expulsion when it is necessary to again fill each pump with the corresponding first and second component; and Again opening the injection valve of the first pump to begin additional injection cycles that repeat the above steps (i)-(iv), the process further comprising: Determining with each closing of an injection valve a volume of component that remains in the corresponding pump, and if the remaining volume is inadequate for an injection of a next dose, then reversing movement of the piston of the pump in a direction of suction and expulsion of the corresponding component at the same time that the injection valve of the other pump is open for injection of a dose of the other component into the mixer.