Commercial storage water heater process

A process for heating water in a tank having a water storage chamber through which an upright cylindrical combustion tube extends and in which a plurality of upright flue tubes extend through the chamber, the process including the steps of placing water within the storage chamber to a level around the upper portion of the combustion tube, disposing a radiant burner having a fiber matrix cylindrical wall forming an outer combustion surface within and radially spaced from the combustion tube, holding the burner at a position where the combustion surface is facing a lower portion of the combustion tube which is below approximately the mid-span of the combustion tube, passing a mixture of fuel and air into the burner and radially outwardly through the burner wall, flamelessly combusting the fuel and air mixture uniformly across the outer combustion surface at a temperature on the order of 1800.degree. F. and at a heat release rate of substantially 120,000 Btu/hr-ft.sup.2, said step of combusting the mixture being carried out in cycles responsive to the temperature of water in the storage chamber falling below a predetermined value, transferring heat from the combustion surface primarily by radiation outwardly to the combustion tube by radiating the heat uniformly to the inner surface of the lower portion of the combustion tube, transferring heat by conduction and convection from the lower portion of the combustion tube to the lower strata of water in the storage tank which surrounds the lower portion and causing cool water in the upper strata surrounding the upper portion of the tube to circulate down in exchange with water in the lower strata heated by the combustion tube, said heat from the lower portion of the combustion tube being transferred to said lower strata to uniformly heat the water therein, passing exhaust gases from said combustion in a path out from the lower end of the combustion tube and upwardly through and in heat exchange relationship with the flue tubes, transferring residual heat from the exhaust gases by conduction and convection through the flue tubes into the water in the storage chamber, said step of transferring heat to the lower strata during each cycle causing said water circulation to be sufficient to minimize stratification of the water temperature and thereby limit temperature rise during such cycle to below another predetermined value, and causing insoluble precipitants from water in the storage chamber to gravitate downwardly and deposit on the lower end of the tank substantially free of the outer surface of the combustion tube.