Eliminating early cut-offs and estimating cycle end time in a tumble dryer

Abstract

Modern domestic clothes dryers contain sensors which attempt to detect when the load is dry, and subsequently, when the drying process should be ceased. However, due to a range of factors, occasionally the dryer may cut-off earlier than is desired. At a recent mathematics-in-industry study group workshop in New Zealand (MINZ-2015), Fisher and Paykel presented the challenge of eliminating these early cut-offs. Using a statistical fitting technique which accounts for stochastic noise and utilises confidence intervals, we outline a more rigorous procedure for detecting the end state of the drying process. We analyse experimental data provided at the workshop and investigate the possibility of estimating drying cycle end time in advance. Finally we interrogate the experimental data to estimate physical drying parameters which may be used in a reaction engineering drying model.