Patent ID: 6289981
Filing Date: 2001-09-18
Classification: F28D,F28F

Abstract:
A multi-bored flat tube for use in a heat exchanger, comprising:a peripheral wall including flat wall portions facing each other at a certain distance and sidewall portions connecting lateral ends of said flat wall portions; anddividing walls each connecting said flat wall portions and dividing an inside space defined by said peripheral wall into a plurality of unit passages arranged in a lateral direction of said tube,wherein said plurality of unit passages include outermost unit passages located at both lateral ends of said tube and a plurality of intermediate unit passages located between said both outermost unit passages,wherein each of said outermost unit passages has a circular-based inner surface in cross-section,wherein each of said plurality of intermediate unit passages has a circular-based inner surface in cross-section, and has a plurality of inner fins formed on said circular-based inner surface and extending in a longitudinal direction of said tube,wherein each of said plurality of inner fins has a triangular cross-sectional shape,wherein said plurality of inner fins are formed continuously along a circumferential direction of said intermediate unit passage; andwherein each of said outermost unit passages has a circumferentially smooth curved inner surface in cross-section.