A FLUIDIZED-BED PROCESS FOR ELECTRON STERILIZATION OF POWDERS

A small capacity (100 g.s(-1)) pilot system is described for presentat ion of powders and fine aggregates at high velocity, to an electron be am. Electron beam dose rate is continuously monitored in real time, wh ile the thickness of the fluidized bed used to pneumatically transport the product can be monitored and controlled using beta-gauge techniqu es. Using electron paramagnetic resonance (EPR) techniques, alanine po wer mixed with the product is used for precise determination of dose d elivered to the powder stream. Thin film dosimeters transported in the bed are also used for dose determination. Results with a variety of p roducts are presented using both dose rate and bed velocity as the ind ependent variables. Lethality data for the bioburdens present in sever al powdered foodstuffs are discussed.