Control process for a laundry dryer working on the drum principle

摘要

The drum of a laundry dryer is to be controlled in respect of the reversing rate and the rotational speed in dependence on the laundry type, laundry quantity and laundry case. Known laundry dryers are controlled via permanently predetermined programmes or via drying-time switches. The control process according to the invention allows shorter drying times and higher overall efficiencies. Drying takes place with extreme care of the fabric and the drying results are highly uniform. The loading quantity is recorded electrically by the trend of the motor current in dependence on the change in rotational speed of the drum. When a predetermined current value is exceeded, there is a change-over to reversing mode. This right/left running continues until the time dependence of the current curve is the same both for the right and for the left running of the drum. The control process can be used both for domestic laundry dryers operating on the waste-air principle and in those working on the condensation principle.