GB232342A - Annealing furnace - Google Patents

Abstract

232,342. Fairweather, H. G. C., (Castings & Supplies, Ltd.). Jan. 21, 1924. Annealing - furnaces; charging and discharging. -For annealing pipes 24, such as cast iron pipes made by a centrifugal process, they are arranged to be axially rotated and progressively passed through a furnace by a series of overlapping rollers 29, 30 that are gapped as shown in Fig. IX., each roller having a major section concentric with its axis and a minor sector which is recessed at 31 to form a crest at one side of the recess. In the preferred constructional arrangement, the rollers are mounted upon trucks 48 so that they can be withdrawn from the furnace; or they may be permanently mounted in the furnace. The rollers are respectively mounted in pairs on the ends of cross-shafts 34, 35 provided with worm-wheels 36 driven by a worm-shaft 38 arranged longitudinally in the furnace or on the truck, and the shaft 38 is operated by a motor positioned at the end of the furnace. Oil-fed combustion chambers 13 are situated at the sides of the furnace, and the combustion products are directed across the underside of the furnace roof and over the pipes 24. A bed of refractory material 54 protects the driving-shafts and operating gear, and the bearings of the shafts are water-cooled. Chain screens 26, 27 close the ends of the furnace. The pipes 24 to be heat treated are introduced into the furnace at a temperature of above 1000‹ F., and they are subjected to a furnace temperature that decreases from about 1400‹ F. until they are cooled to less than 500‹ F.