Fluid motor driven pump arrangement having motive fluid exhaust into the pump chamber

Dosing arrangement for the dosing of at least a first liquid medium A into a second liquid medium B and which comprises a piston type liquid motor which is driven by the second liquid medium B and consists of two mutually connected motor pistons (1, 1') on a common piston rod (12) each motor piston traveling in its own motor cylinder (2, 2'), and having a length of stroke, motor inlet valves (6, 6') and motor outlet valves (7, 7') for delivery and discharge of the second liquid B to and from the motor cylinders (2, 2') and at least one dosing pump, for the first liquid A, the at least one dosing pump being embodied as a piston pump consisting of two pump pistons (3, 3') traveling each in its own pump cylinder (4, 4'), which are positioned outward from, in continuation of and coaxially with the motor cylinders (2, 2') and which are mechanically connected to the motor pistons (1, 1'), motor outlet valves for delivery and discharge of the first liquid medium A to and from the pump cylinders (4, 4'), pipe connections for supply of the first liquid medium A from the dosing pumps to a discharge pipe from the liquid motor, and means for regulation of the proportion of mix, the dosing arrangement comprising the motor pistons and the pump pistons (3, 1, 3', 1') being mutually permanently connected and attached to a central body (5), the one of the motor cylinders and one of the pump cylinders (2, 4, 2', and 4') being positioned on opposite sides of the central body from the other of the motor cylinders and the other of the pump cylinders, the central body having a width which is greater than the length of stroke of the motor piston (1, 1'), in which the motor inlet valves (6, 6') for delivery and the motor outlet valves (7, 7') for discharge of the second liquid B to and from the motor cylinders (2, 2') are built in, the motor inlet valves (6, 6') being embodied as seat valves, which are mutually connected by an inlet valve rod (8) being moved in a direction parallel with the direction of travel of the motor pistons (1, 1'), and which in their extreme positions close a delivery opening (6a, 6a') to the motor cylinders (2, 2'), respectively, the motor inlet valves (6, 6') by means of the inlet valve rod (8) being instantaneously changed from one extreme position to the other by means of a spring mechanism coupled to a push rod (9), said push rod (9) being displacably embedded in the central body (5) so that the push rod can move in a direction parallel with the inlet valve rod (8), being placed and having a length so that when one of the motor inlet valves (6, 6') is closed, the push rod protrudes a short distance (X) into the motor cylinder, respectively (2, 2') and is displaced by the motor piston, (1, 1') when the latter travels towards its bottom dead center towards the central body 5, the motor outlet valves (7, 7') being embodied as seat valves which are mutually connected by an outlet valve rod (10), which is parallel with the inlet valve rod (8) being moved in a direction which is parallel with the direction of movement of the motor inlet valves (6, 6') and in their extreme positions said motor inlet valves (6, 6') can close the discharge openings (11, 11') from the motor cylinders (2, 2'), respectively, and that the movement of the motor outlet valves (7, 7') are firmly coupled to the movement of the motor inlet valves (6, 6'), the central body (5) being hollow and filled with the second liquid medium B, the central body (5) incorporating an opening/closing arrangement which, in correspondence with the movement of a piston rod (12), delivers a desired and variable volume of the second liquid medium B from the central body (5) to the pump cylinder (4 4'), which is under suction pressure.