Electrical steam generator with multiple passages of unequal

Abstract

A steam generator has a body (4) of heat conductive material, an electric heating element (6) located within the body (4), an inlet (14) for water to be vaporized, one or more discharge orifices (20) for steam, and one or more elongate convoluted passageways (26) serving to transfer water and/or steam from the water inlet (14) to the one or more steam discharge orifices (20). The steam generator has first and second chambers (8), (22). The first chamber (8) has relatively wide passageways (12) serving to remove substantially any impurities present from, and preheat, the water, to produce steam which contains entrained water droplets, and which is substantially free from impurities. The second chamber (22) has relatively narrow and convoluted passageways (26) to achieve final heating of the steam to convert any entrained water droplets to steam. The first and second chambers are connected by transfer passages (16, 16A) allowing passage of steam containing entrained 20 water droplets from the first chamber (18) to the second chamber (22).