Providing precise dosage at fluctuating pressures - by keeping pressure differential across metering pump constant

摘要

To admix doses of a component B to a high-pressure flow of a component A, an intensifier pump raises the pressure in the mass flow of B to the maximum possible pressure of A. A side stream, diverted upstream of the metering pump, is controlled to equalise the pressure of B upstream of the metering pump with that of A and to keep the pressure drop across this pump to a constant minimum. This ensures constant dosages of the component B over long periods, even when the pressure in the supply line of the component A is high and/or fluctuates.