GB921053A - Apparatus for heating gases and liquids - Google Patents

Abstract

921,053. Induction heating of fluids. KUHULE, KOPP & KAUSCH A.G. July 28, 1959 [July 31, 1958], No. 25884/59. Class 39 (3). Apparatus for heating fluid media comprises a primary induction coil 2 having within its field a graphite body 1 sealed with an inorganic substance such as silicic acid and having adjacent a surface thereof which is directed towards the coil one or more bores or channels 3 for the passage therethrough of media to be heated. The thickness of the body 1 is at least equal to the depth of penetration produced by the field of the coil in operation at its intended frequency. As shown the graphite body 1, sealed to graphite caps 9, is surrounded by an insulating jacket 4. To avoid damage to the graphite body, the gap between it and the jacket 4 can have an inert medium flowing therethrough and/or the graphite body may be protected by a heatresistant coating. The diameter of the body 1 is preferably 3.5 to 4 times the depth of penetration of the field produced by the coil. To reduce the depth of penetration the body can be provided on the charged or the uncharged surface with a copper or iron coating. In a further embodiment a hollow cylindrical graphite body 20, Fig. 4, having axially parallel bores 21 is disposed in the field of an inner and/or an outer primary coil 23. Alternatively, cylindrical and hollow cylindrical graphite bodies, each provided with a spiral-shaped channel for the medium to be heated, may be coaxially arranged with a primary coil therebetween. Several primary coils, inductively separated by a slotted iron sheet, may be used and cooling fluid may be circulated therethrough. The coils may be bridged by iron yokes or cores. Several heating surfaces may be connected in series, only the last in the direction of flow of the media being in the vicinity of the heating coil, the remainder being heated, for example, by the cooling agents for the induction coil. An iron-nickel alloy having the same coefficient of expansion as graphite can be used for the connecting members 6.