Researches on New Heat Transmitting Tubes : (2nd Report, On the Combination Bundles of Circular and New Finned Tubes)

抄録

We have obtained the heat transmitting tubes of a new type which are superior in point of heat transmission in the case of fluid flowing in them. We have studied experimentally the characteristics of our tubes, and already reported the results. We researched the heat transmission characteristics of the bundles of circular tubes having one, two or three rows of our new 1st tubes ahead. And we researched the characteristics of the ordinary tubes having transverse circular fins on their outer surface. The main results of our researches are as follows : (1) The combination bundle of 1st tubes as the Ist and IInd rows and simple circular tubes as the other rows has the heat transmission ability of more than 95%, and the pressure loss of 85%, comparing with the bundle of 1st tubes only. (2) The 1st tube has the same heat transmission ability as the ordinary ribbed tube, which has the fin area about three times as large as the one of 1st tube.