Numerical modelling of an industrial steam–air sterilisation process with experimental validation

A numerical model has been developed to simulate heat and mass transfer phenomena during a steam–air sterilisation cycle of an operating industrial autoclave. The objective of this paper is to present a practical methodology applicable for evaluating transient heat and mass transfer phenomena by assuming quasi-steady state conditions. As a first step, an empty autoclave was considered. The developed model utilises measured steam flow rates as input parameters and predicts the transient temperature and pressure profiles. The numerical results are validated against two measured on-site data sets, one obtained in summer and the other in winter. The detailed numerical results allow the major heat losses within the process were identified to be determined, thus presenting the importance of having such a numerical model when conducting analyses for evaluating potential thermal energy savings in thermal processes. It is shown, that in any cyclic operation involving the heating and cooling of the containing walls, the insulation should be placed on the heated side.