HEATING FURNACE

摘要

PROBLEM TO BE SOLVED: To provide a heating furnace capable of sufficiently suppressing production of nitrogen oxides while achieving energy saving, and further capable of appropriately heating a heating target.SOLUTION: A heating furnace is configured so that a space temperature of a combustion space N formed within a furnace body 2 is higher than a self-ignition temperature of a gas mixture of a fuel and an oxidant gas. Gas supply means U is configured to supply a fuel gas G and an oxidant gas A in a state in which the gas supply means U divides and supplies one of or each of the fuel gas G and the oxidant gas A to a plurality of flame formation portions in a longitudinal direction of the combustion space N and in a state in which an equivalent ratio to the entire combustion space N is equal to a set equivalent ratio near a stoichiometric ratio, so as to form flames F for heat exchange with a heating target D present in the combustion space N in the flame formation portions. Gas supply conditions for supplying the fuel gas G and the oxidant gas A to the respective flame formation portions are set to conditions that temperatures of the respective flames F formed in the flame formation portions are equal to or lower than a set flame temperature.