GB730375A - Improved heat exchange apparatus - Google Patents

Abstract

<PICT:0730375/III/1> A heat exchanger comprises a casing through which a heating or cooling medium is caused to flow, the casing surrounding a tube assembly comprising superposed sections or bundles of fluid-tight graphite tubes through which flows a liquid to be heated or cooled or a liquid and a gas undergoing heat exchange and/or interaction one with the other, the liquid and/or gas having corrosive properties each tube bundle having at its upper end a horizontal floor (e.g. 4 or 5) with the tube ends projecting above the floor the individual tubes being closed at their upper ends (e.g. by closures 6) and having lateral slot-shaped openings 7 into which liquid can flow from the horizontal floor, the openings 7 being so disposed as to enable the inner walls of the tubes to be wetted uniformly by the liquid in the form of a thin film. In the apparatus shown for the manufacture of hydrochloric acid, hydrochloric acid gas enters through a port 8 and flows upwardly through the tubes in direct contact with and in counter-current to water flowing downwardly through the tubes from an inlet 3. The flow of gas and liquid may however be co-current. Filling members e.g. Raschig rings or rods provided with ball-shaped enlargements (Fig. 4, not shown) may be provided in the last section or last two sections through which the gas passes before leaving the apparatus. The spacing and/or cross-sectional area of the tubes may vary in different sections of the column. The casing is composed of sections (e.g. 1 and 2) corresponding with the tube groups, cooling water flowing through each section from an inlet 9 to an outlet 10. An inlet and an outlet may however be provided at both ends of a casing section. It is stated that the apparatus may be used for other processes in which a gas and liquid interact with evolution or absorption of heat. When used for heating liquids which react with gases, steam or hot liquid is passed through the casing sections.