Patent ID: 6318304
Filing Date: 2001-11-20
Classification: F24H

Abstract:
A water heater including a water tank having an outside surface and a lower portion thereof, a burner producing hot combustion products located at or towards the lower portion of the tank, a casing around at least part of the outside surface of the tank and spaced therefrom so as to define a flue path within the casing and along the outside surface of the tank whereby combustion products can flow along the outside surface of the tank and can therefore heat water within the tank, the water heater further including at least one flow restriction located in the flue path and extending inwardly from the casing towards the outside surface of the tank and forming in generally horizontal section through the flue path a region of restricted flow area whereby the combustion products flowing along the flue path encounter the flow restriction and are restricted and disturbed in flow pattern at said at least one flow restriction, said at least one flow restriction being of limited vertical extent so that combustion products flowing past the flow restriction are again disturbed in their flow upon passing the flow restriction and encountering an increased flow area of the flue path past the flow restriction,wherein there are a plurality of said flow restrictions provided, the flow restrictions being spaced apart in the direction of flow of combustion products so that the combustion products repeatedly encounter flow restrictions in passing along the flue path from the burner before being discharged from the water heater.