1359677 Condensing metal vapours ISC SMELTING Ltd 10 Nov 1972 [29 Nov 1971] 55291/71 Heading C7D [Also in Division F4] A method and apparatus for condensing, zinc vapour or cadmium vapour, in which the vapour is passed through a spray of molten lead droplets produced by the mutual impingement of at least two continuous streams of molten lead at a temperature between 430‹ and 650‹C. As shown the apparatus comprises a vessel 1 divided into upper and lower chambers 1a and 1b. Spray units each consisting of pairs of converging jets in the form of holes or tubes 4, preferably angled at 30 degrees to the horizontal, are provided in the roof of the chamber 1b. The upper chamber 1a is divided into Sections I, II, III by vertical partitions 2, 3. The molten lead in adjacent sections may be arranged to be at different temperatures. Baffles 5 and 6 in the lower chamber 1b constrain the vapour stream to follow a tortuous path. The molten lead, which contains condensed metal, e.g. zinc, and collects on the floor of chamber 1b, is passed into a device wherein the zinc is separated from the lead, the separated lead being pumped back into the chamber 1a for reuse. The condenser apparatus 13 may be located in the cross over duct 10 connecting the upper part of the shaft 11 of a zinc smelting blast furnace with a conventional lead-splash condenser 12 wherein sprays of molten lead droplets are formed by rotation of immersed impellers 15. Zinc vapour present in the offtake gas is thus condensed out.
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