Abstract: In the purification of oil used for example in light metal rolling, and contaminated by abraded particles, a coagulating agent, for example an aqueous soda solution, is added by means of a dosaging device (7) and mixed in a device (5) which comprises a static dispersing device (8) with a jet pump (9) connected thereafter with a recirculation loop (10). The mixing is normally carried out at an elevated temperature and a heating step (3,4) included. After mixing, the coagulates formed are separated, typically in a centrifuge (14). The invention is particularly suited to the purification of the rolling oil occurring in the manufacture of aluminium foils.

Abstract: Ring gap nozzle for distributing a fluid medium over a plate, comprising an axial channel passing through the plate, a cap which covers the channel, leaving a ring gap between it and the plate, and a connecting member extending coaxially through the channel for holding the cap in place. A wall which defines a rotationally symmetrical flow space extends from the connecting member to the outlet edge of the totally free ring gap. The annular flow space comprises a region of the channel, of a deflection space and of the ring gap. All the walls which bound it are arranged so that, starting at least in the deflection space, the flooded area of cross section of the annular flow space decreases continuously in the direction of the flow of medium towards the outlet edge of the ring gap.