VERFAHREN UND VORRICHTUNG FUER DIE INTENSIVE GEGENSTROMKONTAKTIERUNG VON TEILCHENFOERMIGEN FESTSTOFFMATERIALIEN MIT EINER KLEINEN FLUESSIGKEITSMENGE

The invention concerns a process and apparatus for the countercurrent contacting of solid materials with liquids in which an amount of liquid less than that required for ensuring the minimum rate of fluidisation, is caused to flow from below upwardly through a bed of a particulate solid which is either continuously or intermittently fed and discharged. The liquid flow is of varying direction and/or 'broken down' into pulses. The maximum velocity of the upwardly flowing liquid from time to time exceeds the minimum fluidisation velocity. The liquid is finally discharged by overflow 20 above the bed. The solid is charged at the top of vessel 1 and discharged from its bottom. The liquid is added at 6 into auxiliary vessel 4 and the pulses are provided by air under pressure supplied via valve 9a and relieved via valve 9b. Throttles 22, 23 govern the rate of air flow, and hence the shape of the pulse.