Improvements in and relating to methods of and apparatus for preparing sulphur dioxide

摘要

350,739. Sulphur burners. BRITISH THOMSON. HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees, of Nordlander, B. W. ; 19, North Ferry Street, Schenectady, New York, U.S.A.) June 23, 1930, No. 19107. Convention date, June 22, 1929. [Class 51 (ii).] Sulphur dioxide is prepared substantially free from sulphur trioxide by passing preheated air or oxygen in the form of small bubbles through an excess of liquid sulphur. As shown, the sulphur is melted in a chamber 15 by steam supplied to the jacket 18 and coil 19, and the liquid sulphur passes by gravity through the steam-jacketed pipe line 21 to the reaction vessel 13. Air or oxygen under pressure enters by the pipe I, is preheated in the coil 2 by gas burners 5, and.passes through apertures 10 in a hooded pipe 8 into a bed of sand 11 ; the latter is covered by a porous plate 12 through which the air or oxygen percolates to enter the body of liquid sulphur 14 in the form of fine bubbles. The bath 14 is maintained at the necessary temperature by gas jets 45. Secured to the upper end of the vessel 13 and divided therefrom by a perforated plate 27, is a chamber 25 filled with small pebbles 28 and surrounded by a jacket 29 to which cold water and steam are alternately supplied for the purpose of condensing any sulphur vapour and remelting such collected sulphur so that it may flow back to the vessel 13. The sulphur dioxide escapes from the chamber 25 through the outlet 33. To indicate the level of the bath in the vessel 13, the latter is connected to a steam-jacketed tube 35 which encloses an aluminium float 41 and to the upper end of which is secured a graduated glass tube 38 which rejoins the vessel 13 at a point 37<1> above the sulphur level. The tube 38 is enclosed in a shield 381 which is slotted at 39 so that the level of the upper end of the float stem 42 can be read. A modification is described in which the air or oxygen is preheated, before delivery to the sand bed 11, in a coiled tube disposed within the vessel 13, above the level of the liquid sulphur therein.