Finned tube with stepped peaks

Abstract

The current invention includes a tube with a helical fin extending from the tube's outer surface. The fins and tube are monolithic, or formed of one part, with a channel defined between adjacent fins. The fin has a crest with peaks and depressions formed in the crest. The fin peak includes an indent formed in a side surface, and the indent includes a flank and a base surface. The indent flank intersects the fin peak top, and the indent base surface intersects the fin side wall.

1 . A finned tube comprising
 a tube body having an outer surface;   at least one fin extending radially from the tube body outer surface, the fin including a fin crest, a fin base, and a fin height measured from the fin crest to the fin base;   a plurality of fin peaks formed at the fin crest, such that a plurality of fin depressions are defined between the fin peaks, and wherein the fin peak includes a side surface; and   at least one indent defined in the fin peak side surface.   
   
   
       2 . The finned tube of  claim 1  wherein the indent further comprises a flank, a base surface, and a junction defined by the intersection of the flank and base surface, and wherein the junction is substantially parallel with the fin base. 
   
   
       3 . The finned tube of  claim 2  wherein adjacent fins define a channel, and the base surface is received at least partially above the channel. 
   
   
       4 . The finned tube of  claim 1  wherein the fin is formed from the tube body, so the fin is monolithic with the tube body. 
   
   
       5 . The finned tube of  claim 1  wherein the indent includes at least two flanks and two base surfaces, and the fin peak includes a top surface, and wherein only one flank intersects the fin peak top such that the indent includes at least two step-like shapes. 
   
   
       6 . The finned tube of  claim 1  wherein the peak includes two indents, and the indents are on opposite sides of the fin peak. 
   
   
       7 . The finned tube of  claim 1  wherein the tube body includes an inner surface, the finned tube further comprising helical ridges projecting from the tube body inner surface. 
   
   
       8 . A finned tube comprising:
 a tube body having an outer surface;   at least one fin having a left and right side wall, a fin crest and a fin base, the fin helically extending from the tube body outer surface such that a channel is defined between left and right fin side walls of adjacent fins, there being a fin height measured from the fin crest to the fin base;   a plurality of fin peaks formed at the fin crest such that a plurality of fin depressions are defined between the fin peaks, and wherein the fin peak includes a top; and   at least one indent defined in the fin peak, wherein the indent includes a flank surface and a base surface, and the indent flank intersects the fin peak top, the indent base extends into only one channel, and the indent flank faces the channel the indent base extends into.   
   
   
       9 . The finned tube of  claim 8  wherein the fin is formed from the tube body so the fin is monolithic with the tube body. 
   
   
       10 . The finned tube of  claim 8  wherein the indent includes at least two flank surfaces and at least two base surfaces, and only one flank surface intersects the fin peak top, so the indent includes at least two steps. 
   
   
       11 . The finned tube of  claim 8  wherein the indent includes at least two indents on opposite sides of the fin peak. 
   
   
       12 . The finned tube of  claim 8  wherein the tube body includes an inner surface, the finned tube further comprising a helical ridge projecting from the tube body inner surface. 
   
   
       13 . A finned tube comprising:
 a tube body having an outer surface;   at least one fin extending radially from the tube body outer surface, the fin including a side wall, a fin crest, a fin base, and a fin height measured from the fin crest to the fin base; and   a plurality of fin peaks received at the fin crest such that a plurality of fin depressions are defined between the fin peaks, and wherein the fin peak includes at least one stepped side.   
   
   
       14 . The finned tube of  claim 13  wherein the fin peak stepped side includes at least two step-like structures. 
   
   
       15 . The finned tube of  claim 13  wherein the fin peak includes two stepped sides, and the stepped sides are on opposite sides of the fin peak. 
   
   
       16 . The finned tube of  claim 13  wherein the fin is formed from the tube body so the fin is monolithic with the tube body. 
   
   
       17 . The finned tube of  claim 13  wherein the tube body includes an inner surface, the finned tube further comprising a ridge extending from the tube body inner surface. 
   
   
       18 . A method of producing a finned tube comprising:
 providing a tube body;   forming fins on a tube body outer surface,   knurling depressions in the fins such that fin peaks are defined between the depressions; and   pressing off-center indents into the fin peaks such that a fin peak side has a step-like structure.   
   
   
       19 . The method of  claim 18  further comprising forming helical ridges on a tube body inner surface. 
   
   
       20 . The method of  claim 18  wherein off-center indents are pressed into opposite sides of the fin peak. 
   
   
       21 . The method of  claim 18  wherein the indents include at least two step-like structures.