GB678488A - Improvements in or relating to cooling processes and apparatus - Google Patents

Abstract

678,488. Tubular heat-exchangers; surface condensers. PETROCARBON, Ltd., and HOWCROFT, J. W. Oct. 5, 1950, No. 24310/50. Classes 29 and 64(iii) A fluid to be cooled or condensed passes upwardly through a helically coiled tube 4 enclosed in a container 13, and liquid refrigerant is conducted downwardly through a helically coiled conduit 9 having - the form of a channel open at its upper side 11 to the interior of the container, the stream of refrigerant being in contact with at least a part of the surface of the tube over the whole or a major part of its coiled length. The refrigerant liquid may comprise a mixture of refrigerants of different boiling points evaporating at progressively increasing temperatures in the downward direction. The two-start helical tube 4 is coiled around and sealed at 6 to a cylinder 1 and the refrigerant channel 9 is formed by strips 7 of thin metal soldered to the coiled tubes along the line of maximum diameter 8 the upper sides of the turns thus forming the bottom of the helical channel. The upper edge 10 of.each strip extends above the lower part of the tube turn immediately above that to which the strip is soldered so that the refrigerant also contacts the under sides of the turns; and the strips are flared outwards to provide the gap 11. A pipe 16 supplies the liquid refrigerant to a well 3 at the upper end of the cylinder 1 communicating with the channels 9 by holes 12. The refrigerant vapour passes through holes 17 into the cylinder 1 and out through a pipe 18. The fluid to be cooled or condensed is supplied to a header 19 and passes out to a header 23. A number of helices of different diameters may be sealed together to form the base of the refrigerant channel. To tap off condensate from the tubes T-pieces are inserted in the coils and connected to lagged pipes leading inwards and downwards through the cylinder 1 and out through the lower end of the container 13.