APPARATUS FOR HEATING FLUIDS

摘要

The present invention relates to an improved fluid heater apparatus of the type having walls defining a furnace space, a plurality of heating tubes passing through the furnace space and one or more high intensity combustion burners attached to and positioned with respect to the furnace space so that combustion gases are directed under super-atmospheric pressure into the furnace space and circulated around the heating tubes thereby causing the transfer of heat to the fluid being heated. By the present invention walls defining a secondary furnace space, a second plurality of heating tubes and means connecting between the primary and secondary furnace spaces are provided so that spent combustion gases from the primary furnace space flow through the secondary furnace space under super-atmospheric pressure and additional heat is transferred from the spent combustion gases to the fluid being heated.