Modelling of Specific Moisture Extraction Rate and Leakage Ratio in a Condensing Tumble Dryer

The use of tumble dryers in households is becoming more common. Tumble dryers, however, consume large amounts of electric energy. A statistical model over the tumble dryer is created from a design of experiments. The model will be used to find the best settings for the power supply to the heater, the internal airflow and the external airflow in order to reach a high specific moisture extraction rate (SMER) and a low leakage ratio of water vapour. The aim also involves explaining the trends of the SMER and the leakage ratio based on the physics of the tumble dryer drying process. A statistically significant model, which can be used for improving the SMER and leakage ratio, was established from 19 experiments in a condensing tumble dryer. The results show that a high power supply to the heater, a high internal airflow and a low external airflow give the highest SMER values. This combination of settings also results in the largest leakage ratio values for the dryer. Leakage is most affected by the external airflow.