GB579463A - Improvements in or relating to still heads - Google Patents

Abstract

579,463. Still heads. CORNING GLASS WORKS. Feb. 7, 1944, No. 2207. Convention date, March 2, 1943. [Class 32] A still head comprises several condensing surfaces, all arranged in equivalent geometrical relation to a cooling medium, means for returning all of the condensate from some of such surfaces as reflux, and condensate collector means arranged to receive all the condensate from at least one surface as product, the vapors to be condensed having similar or equivalent paths to all the surfaces. The surfaces are preferably arranged in parallel. A form suitable for plant use, Figs. 6, 7, has twenty-four tubes 12 supported by two discs 16 between which cooling fluid flows. The condensate from seventeen of the tubes 12 is returned as reflux. The lower ends of the remaining seven tubes are shaped to form drip points 13 from which the condensate is collected by funnels 15. The condensate collected by four of these funnels is united and may either be removed as product through line 21 or returned as reflux, according to the setting of valve C. Similarly, the condensate from two other of the funnels 15 is directed into line 21 or returned as reflux by valve B. Likewise, the remaining funnel directs condensate into line 21 or returns it as reflux through valve A. By adjusting valves A, B, C reflux ratios in the range 23:1 to 2.43:1 may be obtained. The still head shown in Figs. 4, 5 is made of glass and is suitable for the laboratory separation of materials which start to decompose below their boiling points. Guide ridges 51 are arranged on the outer surface of the condenser 50 which can be rotated about a vertical axis within the fitting 60. A saw-tooth skirt 54 forms a continuation of the base of the outer surface of the condenser and gathers the condensate from the strips of surface between the guide ridges: thus the drops from any one of the strips can be directed into the product line 64, the reflux ratio being determined by the fraction of the condensing surface between the particular guide ridges converging over the internal opening of line 64 at the time. A rod 55 diverts some of the condensate into the device 61 where it is reboiled by means of an electric element in the cavity 62, thus making possible the determination of the equilibrium temperature between the boiling condensate and its vapor with a thermocouple introduced into the thin-walled cavity 63.