The modelling of a domestic tumbler dryer

The characteristics of a small domestic tumbler dryer have been investigated using performance tests and a computer model of the dryer. This model, which was partially developed using the tests results, encompasses all of the energy and mass transfer routes within the complete dryer. The tests demonstrated that the mass and energy transport mechanisms within the dryer drum are not well defined, and a key feature of the model is the simplified equations used to represent these flows. There is a strong correlation between the results from the performance tests and the results predicted by the computer model. The performance test results show that the dryer examined in this study operates at much higher efficiencies than those previously reported. The dryers in the earlier studies were slightly larger and operated with larger air flow rates and higher energy inputs. The drying process generates lint, and the model has been used to demonstrate the effects which the localised accumulation of lint in a trap has on the dryer’s performance. Other operational effects investigated using the model include the influence of fabric type on the performance of the dryer, the sensitivity of the dryer performance to operating conditions and the possibility of energy recovery from the exhaust stream by recirculating part of the stream through the dryer.