Abstract: A heat exchanger fin collar for a plate-fin heat exchanger having close tolerance dimensions for achieving greater contact area on the tube. The fin collar comprises an elongated fin portion for dissipating heat and a leg connected with the fin portion. The leg has a height and includes a straight contact portion substantially perpendicular to the fin portion, wherein the contact portion has a contact height along which the contact portion contacts the tube. The height is in the range of 0.008 to 0.080 inches. It also includes a first curved end portion having a first radius extending from a first end of the contact portion and a stepped transitional portion connecting the contact portion and the elongated fin portion. The transitional portion has a second curved end portion having a second radius, wherein the second curved end portion extends from the contact portion opposite the first end. A method for forming the fin collar and a heat exchanger are also disclosed.

Abstract: A heat exchanger fin collar for a plate-fin heat exchanger having close tolerance dimensions for achieving greater contact area on the tube. The fin collar comprises an elongated fin portion for dissipating heat and a leg connected with the fin portion. The leg has a height and includes a straight contact portion substantially perpendicular to the fin portion, wherein the contact portion has a contact height along which the contact portion contacts the tube. The height is in the range of 0.008 to 0.080 inches. It also includes a first curved end portion having a first radius extending from a first end of the contact portion and a stepped transitional portion connecting the contact portion and the elongated fin portion. The transitional portion has a second curved end portion having a second radius, wherein the second curved end portion extends from the contact portion opposite the first end. A method for forming the fin collar and a heat exchanger are also disclosed.

Abstract: A method for forming an heat exchanger fin collar for a plate-fin heat exchanger having close tolerance dimensions for achieving greater contact area on the tube. The fin collar includes an elongated fin portion for dissipating heat and a leg connected with the fin portion. The leg has a height and includes a straight contact portion substantially perpendicular to the fin portion, wherein the contact portion has a contact height along which the contact portion contacts the tube. The height is in the range of 0.008 to 0.080 inches. It also includes a first curved end portion having a first radius extending from a first end of the contact portion and a stepped transitional portion connecting the contact portion and the elongated fin portion. The transitional portion has a second curved end portion having a second radius, wherein the second curved end portion extends from the contact portion opposite the first end.

Abstract: A method for treating heat exchanger tubing to be expanded by fluidic or electromagnetic expansion. The tubing treatment reduces the increased material hardness of the tubing in areas where cold work has been imparted thereon. By reducing these areas which have increased material hardness, the tubing will have a substantially similar tube yield along its entire length and can therefore be expanded to substantially the same cross-sectional area throughout by either fluidic or electromagnetic expansion. After forming the cold work regions, the regions are annealed with a heat source, such as through flame or induction heating, and are gradually cooled to avoid the effects of quenching.

Abstract: A method of manufacturing a heat exchanger using fluidic expansion, the heat exchanger having tubing sections interconnected to form at least one circuit for transporting a first heat transfer fluid and conductive fins secured to the circuit for increasing the surface area thereof and increasing the heat transfer between the first fluid and a second fluid flowing among the fins. The tubing sections are positioned in a predetermined manner and the fins are disposed therewith and along the length thereof. The inlets and outlets of the tubing sections are then interconnected to form said the fluid circuit. Next, the fins are secured in place so as not become damaged during the sealing of the interconnections, which follows immediately thereafter. Finally, the entire circuit is expanded to enmesh said fins by enclosing the volume of the circuit and introducing an expansion fluid therein at a pressure which surpasses the tube yield strength of the tubing and causes the walls thereof to expand radially outward.