Falling shot heating method and apparatus

A process for heating of an aqueous fluid comprising:

• (a) circulating hard water containing divalent metal ions into a heating zone;
• (b) heating a heat-transfer medium to a temperature above its melting point to produce molten heat-transfer medium at an elevation above said heating zone;
• (c) sparging said molten medium downwardly through said heating zone whereby the sparged molten medium solidifies to form shot particles and said water is heated by said medium as it is cooled and solidified to a temperature sufficient to precipitate a substantial portion of said divalent metal ions as scale in said heating zone;
• (d) recovering hot aqueous fluid from said heating zone;
• (e) recovering cooled shot particles from said heating zone;
• (f) removing said scale from said heating zone in admixture with said shot particles;
• and
• (g) recirculating said shot particles for heating to produce molten heat-transfer medium in accordance with step (b).

In a falling shot fluid heating system, the combination comprising:

• (a) a heating chamber having inlet means for the introduction of fluid and outlet means for the withdrawal of fluid;
• (b) a reservoir located above said heating chamber and adapted to receive solid heat-transfer particles;
• (c) heating means associated with said reservoir for heating particles therein for conversion to the molten state;
• (d) sparging means in said heating chamber and in fluid communication with said reservoir for introducing molten heat-transfer medium from said reservoir into said heating chamber;
• (e) second outlet means for removing solid heat-transfer particles from the bottom of said heating chamber;
• and
• (f) conveyor means communicating with said second outlet means for transporting solid heat-transfer particles recovered from said heating chamber upwardly to said reservoir.