Patent ID: 6095096
Filing Date: 2000-08-01
Classification: F22B,F23C,F23M,Y02E

Abstract:
A package boiler comprising:a boiler housing having two sides, one side being a furnace side, a furnace side enclosure formed by water-cooled membrane tube walls, a floor and a ceiling;at least a pair of multiple firing rate zone burners extending from a first end of the furnace side toward a second end between the water-cooled membrane tube walls, the burners having an operating heat release rate which is substantially constant between the first and second ends of the furnace side; andat least one water-cooled wall of chill tubes extending between the floor and ceiling of the furnace side, each at least one water-cooled wall of chill tubes being located between adjacent ones of the at least a pair of multiple firing rate burners; andwherein the heat released by the multiple firing rate zone burners is balanced to the heat absorbed by the flue gas and the heat absorbed into the water-cooled furnace surfaces so that the furnace gas temperatures inside the boiler are held to a level below 2400.degree. F. the temperature at which thermal NO.sub.X forms.