Patent GB-190300260-A (GB)
Title: Improvements relating to Furnaces for Roasting Pyrites and other Substances.
Inventor: BENKER FREDERIC
Filed: 1903-01-05
Granted: 1903-12-10
Abstract: 260. Benker, F., and Hartmann, E. Jan. 5. Rotary roasting-furnaces ; pyrites burners ; charging and discharging ; fumes, treating.- Relates to furnaces intended chiefly for roasting pyrites and other sulphurous ores in the manufacture of sulphuric acid, but applicable also for roasting ores in general. As shown in Fig. 1, the furnace consists of a long cylinder a provided with a thick refractory lining e, leaving a central passage f of rectangular or other form. It is supported in an inclined position on rollers r at suitable intervals, and is rotated about its axis by worm and wheel gearing. The lower end of the cylinder is closed by a plate b fitted with a damper n for regulating the admission of air, while the upper end is connected with a brickwork chamber i by a short extension d having a central passage g of circular section and formed on the outside with a collar d<11>, which rotates in a groove p<x> in a ring p. This ring is made in halves, bolted to the brickwork, and it can be raised or lowered by means of jacks y in order to vary the inclination of the furnace in accordance with the quantity and nature of the ore to be treated. A passage p<11> is provided in the ring for the circulation of water, which keeps the bearing cool and enables a lubricant to be used. The ore, in a powdered or other state, is charged into the furnace automatically once during each revolution. For this purpose, the charging- opening 1, Figs. 8 and 9, is closed by a spring- controlled slide 4, and provided at one side with a cam-surface 2 for encountering a roller 21 on one end of a lever 18, which is pivoted to the hopper 10 placed above the furnace ; the opposite end 19 of the lever is acted on by a spring. The bottom of the hopper is closed by a slide 12 connected by a rope 15 with a counterweight. As the charging- opening approaches the highest point of its travel, the cam rocks the lever, causing its end 19 to descend and engage a lug 7 on the slide 4, which is thus held stationary in order to uncover the opening. At the same time, a tappet 8 in front of the opening 1 engages a lug 13 and opens the slide 12 so as to allow the ore in the hopper to descend into the furnace. The continued rotation of the furnace releases the slides 4, 12, which then close automatically under the action of the springs 5 and counterweight respectively. A similar arrangement of sliding door is provided to the discharge opening l at the lower end of the furnace. If desired, several furnaces may be placed side by side and operated from a single shaft. In this case, the cases arising from the roasting pass into the chamber i, Figs. 4 and 6, then into a chamber u above, where the sulphur is consumed by the gases from the other furnaces, and afterwards into a chamber v fitted with baffles for changing the direction and velocity of the gases. Finally, they enter a chamber x serving as a settling-chamber for the very fine dust before the gases pass into the Glover tower. Doors or inspection apertures are provided in the chamber i, to give access for cleaning the end of the furnaces and also to enable any furnace to be cut off from the rest in case of stoppage.