GB759710A - Improvements in or relating to the condensation of metal vapours - Google Patents

Abstract

759,710. Condensing metal vapours. NATIONAL SMELTING CO., Ltd. Sept. 17, 1954 [Oct. 6, 1953], No. 27436/53. Class 82(1). The vapours of metals such as zinc are condensed from gases containing them by agitation with molten condensing metal such as lead in a condenser in which the gases are passed between the surface of a bath of molten metal, which is agitated sufficiently violently to communicate the agitation to the gas flowing thereover, and a low roof, the distance between the roof and the surface of the molten metal when unagitated being from 4 to 6 inches. The cross-sectional area of the gas passage through the condenser is preferably less than half of that of the gas inlet. Agitation may be by compressed gas or, as shown in Fig. 1, by pumps. Figs. 1 and 3 show a condenser having gas inlet 7 and outlet 10 and condensing chamber filled with molten condensing metal to level 11, 4-6 inches below roof 8. Molten metal is circulated from external reservoirs 19, 19<SP>1</SP> and 19<SP>11</SP> by pumps 25, escapes from the pump outlet pipe through slots 16 and 17 and returns to the reservoirs through openings 18, 18<SP>1</SP> and 18<SP>11</SP>. Where zinc vapours are produced in a vertical retort or electrothermic furnace by injection of a relatively large amount of air into the base of the retort or furnace the zinc vapour may be condensed by passage through two condensers in series in the first of which zinc is used as a condensing metal and in the second lead. The lead, charged with condensed zinc passes through port 27, passage 28 to chamber 29 from which it is raised by pump 31 to chamber 32 in which it is cooled to a temperature at which zinc separates above the lead and is removed. The remaining lead flows back into the condensing chamber through inlet 26. Specifications 572,961, 686,559, 735,043 are referred to.