Patent ID: 7836942
Filing Date: 2010-11-23
Classification: F24H,F28D,F28F

Abstract:
1. A heat exchanger for a gas boiler for producing hot water; the heat exchanger comprising a casing extending along a first axis (A 1 ) and through which combustion fumes flow; an extruded tube with an oval cross-section having a major axis and a minor axis, the tube having integrally formed longitudinal continuous fins extruded thereon; the tube having only a single integrally formed longitudinal rib extruded thereon on one side and positioned at the intersection of an outer surface thereof aid the minor axis and substantially perpendicular to fins; the single integral rib being partially machined to form a plurality of gap forming teeth there from; the tube being coiled about axis A 1 at a constant pitch so that each resulting turn faces and lies in contact with an adjacent turn with the minor axis being maintained substantially parallel to axis A 1 thereby forming a plurality of turns along which water flows; said turns being arranged inside said casing so that the plurality of teeth contact adjacent turns along the length of the tube so as to form gaps between adjacent turns; a deflector mounted within the turns; and the plurality of spaced apart machined teeth form gaps at an area of the extruded tube cross section having the largest radius.