the collecting bin 1 or is expelled as waste air the screw conveyor 4 sequentially transports a defined amount of preheated and humidified substrate into the pressure vessel 8 of the charging unit 7 when the required filling level of substrate is reached a defined volume of process water is additionally metered into the pressure vessel 8 via a metering unit 20 to achieve a sufficiently watered substrate mixture in order to reduce the heating effort required for the hydrolizer 10 this process water is preheated to between 50 u00b0 c and 100 u00b0 c by the heat exchanger 17 in the flash tank 15 this kind of sequential charging permits accurate control of the mass flows entering the hydrolizer 10 separately for the substrate and the process water this will enable targeted setting of operational parameters and system throughput the pressure vessel 8 of the charging unit 7 is a so called u201c blow gun u201d i e after filling with a charge the vessel is tightly closed against the ambient atmosphere by shutting the intake opening and is brought to the system pressure of the hydrolizer 10 by opening a valve controlled connecting line 11 the valve of the connecting line 11 is then again closed the pressure vessel 8 is emptied cyclically via the valve controlled charging port 9 by the pressure difference between.