Charging valve unit for cellulose digester installations and its use

A charging valve unit (6) for cellulose digester installations for transferring cellulose-containing material, in particular wood chips, contained in a flowable medium, from a circuit at low pressure (8) into one with a relatively higher pressure (2) and having a tubular charging chamber (2) which is connected in an alternating fashion to two inlets on the low pressure or the high pressure side and to two outlets on the low pressure or on the high pressure side, is distinguished in that the charging chamber is arranged in a stationary position and is connected to the inlets and outlets via controlled shut-off valves (36, 38, 40, 42). The shut-off valves (36, 38, 40, 42) are preferably designed as plate-rotary slide valves and lead from the bypass lines (52, 58), which are controlled by valves from the charging chamber (62), to the low pressure or to the high pressure side, in order to equalise the pressure on the shut-off valves (36, 38, 40, 42) on every occasion before they are operated. The relevant charging valve unit is able, even at high differential pressures, to operate reliably and over long periods without maintenance with low leakage losses and is, in addition, simple and cheap to produce.