Km Europa Metal Ag

Ulrich Naumann

Martin Schmidt

Mainhard Hecht

Mathias Konczalla

Use of a low-alloyed, phosphorus-deoxidized copper alloy (DHP-Cu) for manufacturing hollow profile components by internal high-pressure forming, the copper alloy having the following composition: 0.030 to 0.080 wt-% of at least one element of a group including tin (Sn), Zinc (Zn), iron (Fe), silver (Ag) and at least 99.90 wt-% of (Cu) as well as unavoidable impurities as the remainder. Because of its cold work hardening properties, such a copper alloy is especially suitable for the manufacture of hollow profile components by internal high-pressure forming.

Use of a low-alloyed copper alloy and hollow profile component made therefrom

The exchanger tube has a smooth outside surface and a structured inside surface. The inside surface is formed from parallel primary and secondary ribs that run at an angle with respect to the longitudinal tube axis and respectively comprise inclined, planar flanks, channels that are limited laterally by the primary and secondary ribs and troughs shaped into the primary and secondary ribs. The radial extension of the secondary ribs is less than that of the primary ribs. The troughs are triangular. The center longitudinal planes of the troughs are disposed at an angle with respect to the longitudinal tube axis. The summits of the primary and secondary ribs are rounded. Rounded chamfers are provided between the flanks of the primary and secondary ribs and the channel beds.

Heat exchanger tube

A heat exchanger tube having a smooth outer surface and a textured inner surface. The inner surface is composed of parallel ribs which run at an angle deviating from 90.degree. relative to the longitudinal axis of the exchanger tube. The ribs further have inclined flanks, channels delimited on the sides by the ribs, and depressions formed in the ribs, which may run crosswise at a distance from the bottom of the channels. The depressions are formed so as to follow a sine-shaped progression, in longitudinal cross-section of the ribs, which are provided with a surface micro-roughness and which are rounded on the top. The center longitudinal planes of the depressions are arranged at an angle deviating from 90.degree. relative to the longitudinal axis of the exchanger tube. The opposite flanks of adjacent ribs are connected by means of rounded channel bottoms. The micro-roughness of the rib surfaces is produced by corundum blasting or laser beams.

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Menden, Germany

Ulrich Naumann