Pump

Abstract

The invention relates to a pump system for providing and maintaining a controlled outflow, comprising a couple of piston pump units (1a, 1b), having at least two cylinders (2a, 2b, 2c, 2d) each with a piston (3a, 3b, 3c, 3d) slidably arranged in each cylinder. It further comprises devices for controllably moving the piston in each cylinder, namely by an eccentric wheel (15a, 15b, 15c, 15d) for each of the pistons, acting on one end thereof. There is also provided a control unit for dynamically changing the speed of movement of the devices for moving the piston, in response to pressure changes in the system on the pressure side, for maintaining a desired flow out of the pump. The pump system further comprises switching valves (10a, 10b) for proportioning solutions to be mixed according to a predetermined ratio, the valves being switchable between each source of solutions (A, B, A′, B′) and are controlled by a control unit having integrating method for integrating the flow during suction from a first source of solution to be mixed, and a method for switching to another source of solution when the integration corresponds to the predetermined proportion of the solution being sucked.

Dependencies are inferred from the claim text.