Patent ID: 7334542
Filing Date: 2008-02-26
Classification: F22B

Abstract:
1. A boiler comprising: a lower drum adapted to receive water; an upper drum having a heated fluid outlet; a plurality of conduits adapted to transfer fluid from the lower drum to the upper drum; at least one downcomer adapted to transfer fluid from the upper drum to the lower drum; a combustion chamber having an inlet adapted to receive heat from a source of combustion and an outlet adapted to discharge a heated gas, wherein walls of the combustion chamber comprise at least some of the plurality of conduits; a first heat transfer chamber having an inlet adapted to receive the heated gas from the combustion chamber and an outlet, wherein walls of the first heat transfer chamber comprise at least some of the plurality of conduits; and a second heat transfer chamber positioned below the first heat transfer chamber, the second heat transfer chamber having an inlet adapted to receive the heated gas from the outlet of the first heat transfer chamber and a outlet, wherein walls of the second heat transfer chamber comprise at least some of the plurality of conduits; wherein the first heat transfer chamber positioned above the second heat transfer chamber receives the heated gas from the combustion chamber prior to the second heat transfer chamber and wherein heated fluid is discharged from the heated fluid outlet of the upper drum.