Patent ID: 6167950
Filing Date: 2001-01-02
Classification: F28F

Abstract:
An improved heat transfer tube (10) in which the improvement comprises: at least one external fin convolution (20) disposed helically about said tube; notches (30) extending radially into said fin convolution at intervals about the circumference of said tube; each of said notches having a base axis that is at an oblique angle (.alpha.) with respect to the longitudinal axis (A.sub.T) of said tube ranging from between 40 and 70 degrees; said notches dividing said fin convolution into a proximal portion (21) having a maximum width (W.sub.r) and a spike portion (22) having a single distal tip (23), said spike portion being between a pair of adjacent said notches and having a maximum width (W.sub.t) that is greater than the maximum width (W.sub.r) of said proximal portion and a distal tip axis (.beta.) that is oblique to said notch base axis.