DEVICE FOR INTRODUCING GAS INTO A FLOTATION SYSTEM AND ITS USE IN PAPER PLANTS, PARTICULARLY FOR INKING OF OLD PAPERS

摘要

In a gassing device, in particular for a flotation device, a higher gas loading is achieved by using a stage diffusor (1) having a cross-section which widens stepwise, the gas feed line (8) ending immediately downstream of a widening (5). In this way, a gas loading of more than 50% can be achieved, if the mixing length (V1 + V2)/A0, that is say the ratio of the mixing volume downstream of the gas feed to the entry cross-section, is at least 1 m. Such devices are particularly suitable for effecting cleaning of fibre material suspensions, obtained from waste paper, by removal of foreign materials for the purpose of producing clean paper from waste paper. IMAGE