Abstract: A metallic heat exchanger tube (1) with a tube wall (2) and with integrally formed ribs (3) which run around on the tube outside (21) and which have a rib foot (31), rib flanks (32) and a rib tip (33), the rib foot (31) projecting essentially radially from the tube wall (2), and the rib flanks (32) being provided with additional structural elements which are formed as material projections (4) arranged laterally on the rib flank (32), the material projections (4) having a plurality of boundary faces (41, 42), at least one of the boundary faces (42) of at least one material projection (4) being curved convexly.

Abstract: 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.

Abstract: The invention relates to a heat exchanger tube with a tube axis, with a tube wall, with a tube outside and with 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 in each case between adjacent inner ribs. The rib tip has at regular intervals recurring elevations which have an essentially frustopyramidal form. In the solution according to the invention, the rib flanks of 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, in that 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.

Abstract: The invention relates to a metallic heat exchanger tube (1) with a tube wall (2) and with integrally formed ribs (3) which run around on the tube outside (21) and which have a rib foot (31), rib flanks (32) and a rib tip (33), the rib foot (31) projecting essentially radially from the tube wall (2), and the rib flanks (32) being provided with additional structural elements which are formed as material projections (4) arranged laterally on the rib flank (32), the material projections (4) having a plurality of boundary faces (41, 42), at least one of the boundary faces (42) of at least one material projection (4) being curved convexly.

Abstract: The invention relates to a heat exchanger tube with a tube axis and with a tube wall having a tube outside and a tube inside, axially parallel or helically encircling inner ribs, with a groove which lies in each case between adjacent inner ribs, being formed from the tube wall on the tube inside, the helix angle, measured with respect to the tube axis, of the inner ribs being smaller than or equal to 45°, the region of the inner ribs which is remote from the tube wall being deformed at regular intervals asymmetrically on one side essentially in the tube circumferential direction, the deformed material of the inner ribs forming protrusions above the groove, the protrusions extending in each case over a finite deformation zone along an inner rib, the markedness of the deformation changing continuously within the deformation zone, the deformation being marked to a greater extent in the middle of the deformation zone then at the margins, and cavities which assist the formation of bubbles being located between the

Abstract: The invention relates to the use of a heat exchanger tube, comprising a copper alloy, which contains the alloying elements [in percent by weight] 0.05-3% Fe, 0.01-0.15% P, and optionally 0.05-0.2% Zn, 0.02-0.05% Sn and residual Cu as well as unavoidable impurities, as a gas-cooler, condenser or evaporator tube of a refrigerator or heat pump operating with CO2.

Abstract: The invention relates to a metallic heat exchanger tube with 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. Said secondary groove is delimited toward the primary groove by a pair of mutually opposite material projections formed from material of respectively adjacent fin bases. Said material projections extend continuously along the primary groove. The cross section of the secondary groove is varied at regular intervals without having an influence on the shape of the fins. There is a spacing between the opposite material projections, said spacing being varied at regular intervals, as a result of which local cavities are formed.

Abstract: 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.

Abstract: The invention relates to a heat exchanger tube with at least one structured region on the inside of the tube, which has the following features: a) integral internal ribs of height H run on the inside of the tube in axially parallel or helical-line-shaped manner continuously over the circumference at an angle of inclination ?1, measured with respect to the tube axis, with primary grooves being formed, b) the internal ribs are crossed over the entire circumference of the tube by spaced-apart secondary grooves which, parallel to one another at an angle of inclination ?2, measured with respect to the tube axis, have a notch depth T2 and a groove opening angle ?2, c) the internal ribs and the secondary grooves are crossed over the entire circumference of the tube by spaced-apart tertiary grooves which run continuously over the circumference parallel to one another at an angle of inclination ?3, measured with respect to the tube axis, and have a notch depth T3 and a groove opening angle ?3.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 reentrant 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.

Abstract: The invention relates to heat-exchanger tubes structured on both inner and outer sides with excellent heat-transfer characteristics, which have recesses on the outside and ribs with specific dimensions on the inside. The structuring tools utilized for the various method modifications are adjusted in such a manner that they are not only able to create aligned, continuous grooves and non-aligned, spaced apart recesses but also secondary structures. The heat-exchanger tubes provided preferably with smooth end sections and smooth intermediate sections are utilized in particular in shell and tube heat-exchangers.

Abstract: The invention relates to a heat-transfer tube, in particular an evaporator tube, with fins circumferentially extending on the shellside, which fins are shaped to essentially closed-off channels. The channels are open to the outside through pores with at least two variable sizes. In order to improve the evaporation characteristics, the invention provides advantageous regions for the ratio of the pore sizes and the ratio of the number of pores.

Abstract: 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.

Abstract: The invention relates to a heat-transfer tube, in particular an evaporator tube, with fins circumferentially extending on the shellside, which fins are shaped to essentially closed-off channels. The channels are open to the outside through pores with at least two variable sizes. In order to improve the evaporation characteristics, the invention provides advantageous regions for the ratio of the pore sizes and the ratio of the number of pores.

Abstract: The invention relates to heat-exchanger tubes structured on both inner and outer sides with excellent heat-transfer characteristics, which have recesses on the outside and ribs with specific dimensions on the inside. The structuring tools utilized for the various method modifications are adjusted in such a manner that they are not only able to create aligned, continuous grooves and non-aligned, spaced apart recesses but also secondary structures. The heat-exchanger tubes provided preferably with smooth end sections and smooth intermediate sections are utilized in particular in shell and tube heat-exchangers.

Abstract: A process for producing a heat exchanger tube (1) with a highly porous surface structure, in particular for evaporating liquids from pure substances or mixtures on the outside of the tube. The process starts from a rolling operation, by means of which helical fins (2) are produced on the outside of the tube, which fins, in turn, are deformed in a plurality of compression steps by means of gearwheel-like compression wheels (6, 7) in such a manner that the projections (12a, 12b) formed in each case form a cover (3a) for the passages (3) which are situated between the fins (2). The high level of porosity is achieved as a result of the remaining pores (13) and/or slots (14).