Wieland-werke Ag

Andreas Knoepfler

Andreas Beutler

Andreas Schwitalla

Ronald Lutz

Manfred Knab

Gerhard Schuez

Axel Kriegsmann

Klaus Menze

Jean El Hajal

Karine Brand

A metallic heat exchanger tube has fins which run helically around the outside of the tube, are molded integrally therefrom and are of continuous design and the fin base of which protrudes substantially radially from the tube wall, and with primary grooves located between respectively adjacent fins. At least one undercut secondary groove is arranged in the region of the groove base of the primary grooves. The secondary groove is delimited toward the primary groove by a pair of mutually opposite material projections formed from the material of respectively adjacent fin bases and the cross-section thereof is varied at regular intervals without having an influence on the shape of the fins. There is a spacing between the opposite material projections, the spacing being varied at regular intervals, as a result of which local cavities are formed.

Evaporator tube with optimized undercuts on the groove base

The invention relates to a heat-exchanger tube structured on both sides with excellent heat transfer characteristics utilizing both outer and also inner fins and secondary grooves intersecting the inner fins. Two spaced-apart rolling tools are provided in the utilized device in order to form the outer fins of two adjacent rolling tools; the inner structure is formed by two differently profiled mandrels. The first mandrel forms in a first forming area the inner fins. The second mandrel forms in a second forming area the inventive secondary grooves into the earlier created inner fins.

Method of manufacture of heat-exchanger tube structured on both sides

A metallic heat transfer tube, in particular for the evaporation of liquids from pure substances or mixtures on the outside of the tube. Fins are integrally formed on the outside of the tube. Recesses are arranged in the area of the base of the primary grooves and extend between the fins. The recesses are in the form of re-entrant secondary grooves. The mechanical stability of the tube is not negatively influenced because material is primarily removed from the fin flanks toward the base of the groove so that the re-entrant secondary grooves are radially open.

Heat transfer tube and a method of fabrication thereof

Method of fabricating a heat exchanger tube

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Ulm, Germany

Andreas Knoepfler