Development of a spatially and timely resolved CFD model of a steam sterilizer to predict the load temperature and the theoretical inactivation of bacteria based on sterilization parameters

Abstract

This paper presents a CFD model to predict the fluid flow, fluid temperature, load temperature and the theoretical inactivation of bacteria in a modern steam sterilizer, with three significant modifications compared to current state-of-the-art simulations of steam sterilizers. 1) The fluid and the load temperature was investigated for unwrapped load. Measurements of the fluid temperature and the load temperature were performed to validate the CFD model. The average error between the simulated and the measured temperatures was below 0.4 K. 2) The steam quality inside a steam sterilizer was investigated for unwrapped load. With the developed CFD model it is possible to predict the steam quality inside the steam sterilizer spatially and temporally resolved. 3) A first order reaction kinetic approach was added to the CFD model to predict the theoretical inactivation of two different types of bacteria in the steam sterilizer, as well as on the surface of the unwrapped load based on sterilization parameters. The results indicate that the CFD model is able to predict the theoretical inactivation of bacteria on the surface of the load, based on sterilization parameters. Keywords: Steam sterilization, Computational fluid dynamics (CFD), Heat transfer, Inactivation of bacteria, Multiphase flow