Method for the production of a spiral falling-film evaporator tube

摘要

The spiral falling-film evaporator tube (1) has a bead (2) with a drip edge (6), which bead runs in a spiral from top to bottom, is convex on the outside of the tube and concave on the inside of the tube, and has, adjoining this bead, a surface structure (7), in the form of longitudinal grooves, for example, each distributed over the entire circumference between two turns and acting as the actual heating surface F. The aim is to specify a method by which, despite its complex shape, this tube (1) can be produced in a simple and inexpensive manner. The spiral falling-film evaporator tube (1) is formed at a plurality of stations (A, B) from a strip (11) of predetermined width and thickness. In a first apparatus (14), the strip is converted to an approximately U-shaped cross-section (16, 17, 18). In a second apparatus (20), a structure (21) which produces the subsequent surface structure is introduced into the base (16) of this cross-sectional shape. In a third apparatus (22), this preliminary profile is wound on to a mandrel (25) to give a helical coil and this coil is then joined together at the seams in another apparatus (29). An appropriate length of tube (1) is then cut from the tube thus obtained. Together with a surrounding tube, the spiral falling-film evaporator tube (1) forms an evaporator/condenser unit as part of an evaporator, e.g. in water treatment, seawater desalination, ... Original abstract incomplete.