HEATERS

摘要

A flow heater comprises a heated flow conduit (12) for heating liquid therein to a temperature below boiling and a final heating chamber (18) for heating the liquid to boiling. The heating chamber (18) comprises a space above the liquid surface for allowing the escape of steam from the liquid surface. A liquid outlet (20; 102) may be configured to maintain a substantially constant level of liquid as the liquid inlet flow rate varies between a predetermined maximum and a predetermined minimum.