GB426728A - Mechanical furnace for roasting sulphurous ores - Google Patents

Abstract

426,728. Ore - roasting furnaces. MUELLER, W., 1, Schillerstrasse, Gleiwitz, Germany. Oct. 9, 1933, No. 27776. Convention date, Oct. 18, 1932. [Class 51 (ii)] In a superposed-hearth ore-roasting furnace having alternate stationary and rotary hearths 1, 2, rabble arms 6 carrying teeth 7 are removably secured to the underside of each hearth by the provision on the latter of a groove 9, Fig. 3b, or rib 9<a>, Fig. 4, for engagement with a complementary rib 8 or groove 8<a> on the upper face of the arm 6. Removal of both sets of arms is effected from the periphery of the furnace after disconnection of the cooling system and release of clamping devices which secure the arms in operative position. The arms are cooled by the circulation of air through built-in conduits 6<a>, the supply and discharge being effected in the case of stationary hearths, through pipes 12, 13 and 12<a>, 13<a> respectively, and in the case of the rotary hearths, through a double-walled central shaft 10. The main portion of the air thus heated is supplied through openings, (not shown), to the centre and periphery of the roasting chambers, while the remainder passes through extensions of the pipes 12<a>, 13<a> to the points 14, 19 where it serves respectively to support combustion in the furnace 17 and to sweep out any sulphurous gases from the discharge hopper. The furnace 17 supplies heating gases to flues 18 disposed immediately beneath the lowermost hearth 16. The stationary hearths 1 are mounted so as to be vertically adjustable, while the intermediate hearths 2 carry rollers R running on brackets K and are rotated by the engagement of pinions 4 on a vertical driving shaft 5 with peripheral racks 3.