The invention relates to the batch treatment of goods with gas, steam or vapor,for example sterilization and drying. The distribution of the medium surroundingthe load (8) during all stages of such a process is important. According to theinvention, movement of fluids within a batch treatment apparatus is achievedusing a fluid ejector device (9), An apparatus for the gas, steam or vapor treatmentof objects is provided, said apparatus having inside a closable chamber (1) atleast one ejector device (9) of the type having a straight flow path for the secondarystream. Any particular fluid or mixture of different fluids entering the chamberduring a treatment process may be introduced via an ejector device (9) in orderto distribute the fluid around the load (8), or remove material deposited on theload (8). The invention eliminates the need for shaft seal arrangements involvedwith fans.
