Heat exchanger tube and methods for producing a heat exchanger tube

Patent metadata

Field	Value
Publication number	US-10024607-B2
Application number	US-201514849101-A
Country	US
Kind code	B2
Filing date	Sep 9, 2015
Priority date	Dec 22, 2009
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A heat exchanger tube with a tube axis, a tube wall, a tube outside and a tube inside. Continuously running, axially parallel or helically circling inner ribs are formed out of the tube wall on the tube inside, each inner rib having two rib flanks and a rib tip. A continuously extending groove is formed between adjacent inner ribs. The rib tip has at regular intervals recurring elevations which have an essentially frustopyramidal form. The inner ribs are raised in the radial direction on the contour line which is defined by the transitional edge of a rib flank to the rib tip and protuberances advancing out of the rib flank are formed in this region. Furthermore, the invention relates to a method for producing a heat exchanger tube.

First claim

What is claimed is:

1. A method for producing a heat exchanger tube, comprising the steps of:
deforming the wall of a smooth tube ( 10 ) radially in a first forming region by a first rolling tool ( 300 ) encircling the outside of the smooth tube to form helically running outer ribs ( 4 ) of a first height on the outside of the smooth tube;
supporting the tube wall in the first forming region with a first rolling mandrel ( 100 ) which lies inside of the tube, is mounted rotatably therein and has axially parallel or helical grooves of a depth T 1 provided on its mandrel outer face and forming an inner structure on the inside of the tube wall out of material of the tube wall pressed into the grooves of the first rolling mandrel;
forming outer ribs with an increased rising height on the outside of the tube wall in a second forming region spaced apart from the first forming region;
supporting the tube wall in the second forming region with a second rolling mandrel ( 200 ) which lies inside the tube, is mounted rotatably therein and has axially parallel or helical grooves of a depth T 2 provided on its mandrel outer face and newly forming helical, continuously running inner ribs ( 3 ) from material of the tube wall and material of the first inner structure both being pressed into the grooves of the second rolling mandrel, wherein the inner ribs formed in the second forming region are more pronounced than the inner structure formed in the first forming region and elevations ( 34 ) on the tip of the inner ribs ( 3 ) are formed from material pressed into the grooves of the first rolling mandrel ( 100 ) in the first forming region.

2. The method according to claim 1 , characterized in that, by means of the inner structure formed in the first forming region, the inner surface area of the tube having this inner structure is increased by from 4-30% with respect to the inner surface area of the non-deformed smooth tube ( 10 ).

3. The method according to claim 1 , characterized in that the depth T 2 of the grooves of the second rolling mandrel ( 200 ) is at least 2.5 times as great as the depth T 1 of the grooves of the first rolling mandrel ( 100 ).

4. The method according to claim 1 , characterized in that the flank angle of the grooves of the first rolling mandrel ( 100 ) amounts at most to 120°.

Assignees

• Wieland Werke Ag

Inventors

• Gotterbarm Achim
• Lutz Ronald
• Beutler Andreas

Classifications

• Y10T29/49391

  Tube making or reforming · CPC title

• F28F1/40 Primary

  the means being only inside the tubular element · CPC title

• B21H7/187

  Rolling helical or rectilinear grooves · CPC title

• B21C37/207

  with helical guides · CPC title

• F28F13/187

  especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites · CPC title