POSITIVE-DISPLACEMENT PUMP AND A DEVICE COMPRISING THIS POSITIVE-DISPLACEMENT PUMP FOR DOSING AT LEAST ONE FREE-FLOWING CONSTITUENT

摘要

Positive displacement pump (1), a cylinder (1a, 1b) comprising, in which a piston (4) by means of a drive (3, 7, 8) is movable back and forth, wherein a seal the piston (4), and in sealing manner on the outer wall of the piston (4) as well as on the inner wall of the cylinder (1a, 1b) is applied, and the seal (40) the cylinder into a first and a second space (5, 6), and the first space filled with a medium (5) with a connecting line (10) is in communication, via which the medium by the movement of the piston (4) from the space (5) of the cylinder or pushed out into the latter can be conveyed, characterized in that a pressure generating means (14) in the second space (6) adjusts a pressure, which corresponds approximately to the pressure in the first space (5) prevails.