Pre-heater

Claim 1

An industrial oven, including the combination of: (a) a steam generating tank having a fluid inlet and steam outlet; (b) walls depending from said tank and defining a combustion chamber therebelow; (c) said tank presenting a stepped portion within said combustion chamber; (d) a preheater associated with one of said walls exteriorally of said combustion chamber and having a water inlet therein, and a water outlet thereof, said preheater water outlet communicating with the tank inlet; (e) said preheater located in the region adjacent said tank and opposite said stepped portion so as to concentrate heat energy between said preheater and said stepped portion of said tank; (f) said preheater including a wall adapted to contact an overlap one of said stepped portions in said combustion chamber; (g) means for generating heat energy within said combustion chamber so as to preheat water within said preheater and generate steam from water within said tank; (h) means for controlling the introduction of water into said preheater and into said tank so as to minimize the drop of steam pressure in said tank during introduction of water into said tank; (i) said tank including a steam generator in the region adjacent said steam outlet for separating water from said steam in said tank.