GB667281A - Improvements relating to heat exchange apparatus for the cooling of fluids - Google Patents

Abstract

<PICT:0667281/III/1> <PICT:0667281/III/2> A medium to be cooled, e.g. a mixture of gases such as coke oven gas having condensible components such as benzene, flows in a helical path around a core 3 in a tubular casing 1 and over cooling elements, e.g. tubes 8 through which flows a cooling medium. Moreover, as seen in section, Fig. 2, the axes of the elements lie in concentric circles, the spacing between axes of adjacent elements of a circular series being the same for the whole nest, i.e. at least three and preferably four times the diameter of an element 8, and the radial widths of the annular spaces between the successive circular series, i.e. the distance between circles less the diameter of one element in each case, increase from the core outwards in substantial proportion to the mean radii of the successive annular spaces. It will be seen that the radii of the circles increase outwardly approximately in geometric progression. As an approximation, the widths of the annular spaces may be proportional to the radii of the circular series. The arrangement is said to permit the linear velocity of the medium to be cooled to be the same over the width of the helical path. A helical wall 2 forms the path, up from an inlet 4 to an outlet 5, for gases to be cooled. The cooling medium flows through the tubes 8 from inlets 6 to outlet 9 and condensate from the cooled gases flows down the helical wall to an outlet 11. A benzene column may have 1,400-2,600 tubes 8, each of 0.75 cm. diameter, and a helical path of 6-17 convolution.