Domestic dishwashing machine with electric water heating - uses waste heat from remaining operating cycles to preheat rinsing water

摘要

The dishwashing machine has a programme control allowing for washing, two successive rinsing stages and final drying. The machine has a heat exchanger (9) thermally coupled to the rinsing drum (2) which is filled with cold fresh water during the first rinsing and the drying cycle so that the water can be heated and fed to a reservoir (13) before using it for the final rinsing cycle. Pref. the rinsing drum (2) is made of sheet metal and has a sump (3) filled with the washing or rising water and containing an electric heating element (5) for heating the latter according to the different programme cycles. The heat exchanger (9) is formed by a tube length extending in contact with the outside of one wall (8) of the rinsing drum (2) and feeding the heated fresh water to a reservoir (13) surrounded by a heat-insulatinq jacket (12). The reservoir (13) feeds fresh water to the sump (3) via an electromagnetic outlet valve (15). The dishwashing machine achieves economic operation by supplementing the water heating provided by the electric heating element.