Abstract: The invention relates to a metallic heat-exchanger tube (1) with fins (2) which annularly or helically extend or rather extend in axial direction on the outside of the tube for condensing of vapor from pure substances or mixtures on the outside of the tube. To improve the condensation performance by effecting a thinning of a liquid film, the invention includes a making of the fins so that they have a constant fin height H throughout, with the fin flanks (4) being structured by spaced-apart depressions.

Abstract: A metallic finned tube, in particular for heat exchangers, which includes multiple integral fins helically extending on the outside, with the n fin run starts starting at the start of the tube and are evenly distributed around the tube periphery. The finned tube has a number of fin run starts n.gtoreq.4 with at least one group having at least two side-by-side oriented fin run starts (A.sub.1, A.sub.2 or rather A.sub.3, A.sub.4 . . . ).

Abstract: A heat exchanger wall for the transfer of heat from one first medium on one side of the wall to a second medium to be evaporated on the other side of the wall, with this other side having integral, aligned distributor grooves for distributing the liquid phase of the second medium. Good distribution of the liquid on the surface of the heat exchanger wall and simultaneous good vaporization characteristics are guaranteed according to the invention by the following characteristics:a) the distributor grooves cross channels having a pitch t, which channels lie below the distributor grooves,b) the distributor grooves are formed by laterally displaced material of the channel walls, with the depth T of the distributor grooves lying approximately between 30% and 90% of the channel height h, andc) the distributor grooves are connected to the channels through flared segments and/or openings in the distributor grooves.