Thermal softening process

A process for heating and softening of hard water by direct heat exchange with steam. The steam is directly sparged into the hard water within a reaction zone and condensed in the water under a pressure sufficient to prevent boiling at the reaction zone temperature. The heated water is then withdrawn from the reaction zone without substantial vaporization of water and filtered to remove scale precipitates resulting from the heating step. At least a portion of the softened water may be heated to generate wet steam which is then recirculated to the reaction zone and sparged into the hard water therein.