Direct-contact type hot water heater

Claim 1

A direct-contact type hot water heater comprising: (a) a hot water reservoir; (b) a high-temperature gas feed chamber located: (i) in an inside section of a heater body having an internal wall and (ii) above said hot water reservoir; (c) an endothermic chamber located: (i) in an inside section of said heater body and (ii) above said high-temperature gas feed chamber; (d) an endothermic material located in said endothermic chamber; (e) means for spraying water over said endothermic material; (f) means for generating a flame in said high-temperature gas feed chamber in order to burn gas therein; and (g) a perforated plate located between said high-temperature gas feed chamber and said endothermic chamber and supporting said endothermic material, said perforated plate extending from side to side of said internal wall, being in peripheral contact with said internal wall over the full extent of its own periphery, and having a top apex, a plurality of apertures therethrough, and a slope which allows water to flow down from its top apex in the form of a water film, said plurality of apertures being sized and shaped so that, in use: (i) the high temperature gas passes upwardly therethrough; (ii) the water does not pass downwardly therethrough due to the surface tension of the water; and (iii) said endothermic material does not project downwardly into said apertures to break the surface tension.