Method of making heat exchange tubing assembly

Abstract

An improved heat exchange tubing and blade assembly and a method for fabricating the same are described. The heat exchange assembly comprises an elongated tube and an elongated heat exchange blade strip positioned thereon, said strip including an array of integrally formed blade segments which extend from a U-shaped support segment. Surfaces of the blades extend at a favorable angle of attack to the incident fluid flow stream, and in a preferred embodiment the chords of the blades extend substantially normal to the length of the tube. The strip is supported on an outer surface of the tube, and means integrally formed with the tube maintain the support segment in thermal contact with the tube. In a preferred embodiment, the tube has a generally streamlined oval cross section for utilization in heat exchanger apparatus such as air conditioner, refrigerator or heat pump, with the tubing arranged such that the minor axis of the oval extends perpendicular to external fluid flow and its major axis extends parallel therewith for reducing frictional drag and reducing stagnant regions of external fluid flow. Multiple blades fan out from opposite sides of the oval tubing along its two gently curving arcuate faces where fluid flow is relatively unimpeded. The individual blades in a preferred embodiment are tapered, decreasing in thickness from root to tip, thereby reducing mass and weight of thermally conductive material in the blade strips while providing suitable thermal conduction and mechanical strength in individual blades.