Patent ID: 6817319
Filing Date: 2004-11-16
Classification: F22B

Abstract:
A boiler in which a liquid medium is heated, said boiler comprising:a housing having first and second ends; a lower drum for receiving the liquid medium, at least a portion of said lower drum being disposed within said housing; an upper drum at least a portion of which is disposed within an upper portion of said housing, said upper drum having an outlet; at least a first tube bank disposed within said housing on a first side of said upper drum, said first tube bank including a plurality of first fluid tubes for establishing fluid communication between said lower drum and said upper drum, each said first fluid tube defining at least one inwardly extending portion; at least a second tube bank disposed within said housing on a second side of said upper drum, said second tube bank being disposed substantially opposite said first tube bank, said second tube bank including a plurality of second fluid tubes for establishing fluid communication between said lower drum and said upper drum, each said second fluid tube defining at least one inwardly extending portion which is longer than said inwardly extending portions of said first fluid tubes of said first tube bank, whereby said first and second tube banks define a combustion area within said housing, and cooperatively define with said housing at least a first level of passageways for communicating hot gases; a burner for generating hot gases within said combustion area; and means for communicating hot gases from said combustion area to said first level of passageways and for communicating hot gases from said first level of passageways to said upper portion of said housing, whereby heat from said hot gases is transferred to the liquid medium within said first and second fluid tubes thereby heating the liquid medium.