GB808052A - Improvements in or relating to vertical shaft-type indurating furnaces - Google Patents

Abstract

808,052. Discharging shaft furnaces. ERIE MINING CO. March 6, 1957, No. 7414/57. Class 51 (2). A vertical shaft type indurating furnace through which discrete fluent bodies descend in a continuous column comprising an upper, straight - walled heating chamber, an intermediate soaking chamber and a lower cooling chamber with a restricted outlet at the bottom and upper and lower rows of horizontal rotatable breaker shafts in the cooling chamber, the upper row having one less shaft than the lower row. Ore pellets fed to the top of a rectangular section indurating furnace, Fig. 2, are heated in the vertical sided upper section H by gases entering downwardly through nozzles 48 from combustion chambers 45 at either long side of the furnace. The long sides of the second soaking chamber S slope slightly inwards from top to bottom to leave spaces into which the nozzles 48 discharge. The lowermost cooling chamber C divides at the bottom into two equal inverted pyramidal sections 25 leading to square discharge ducts 26 and hopper 27. Cooling air or gas from the chamber C enters the combustion chambers 45 through outlets 52 formed by masonry arches 53 supported by pilasters projecting from the long walls. Dust is led from the hopper bottoms of the combustion chambers through a vibratory discharge device 75 to the pellet discharging mechanism 68 below the hoppers 27. Above the division of the chamber C hollow studded breaker rollers 81, 82, Fig. 3, are mounted in two rows, the upper row having one less roller than the lower row. The rollers 81, 82 project through shield-plates 93 depending from the long walls of the furnace, and are journalled in bearings in plates 84 secured to the upper edges of side-plates 90 which define the lower pyramidal parts of the chamber C. The spaces between shields 93 and plates 90 form plenum chambers from which cooling air escapes at the lower edges of the shields 93, and through ducts 161, 162 between the rollers 82 of the lower row. The ducts 161, 162 have lowered side walls, and ducts 161 have open bottom troughlike lower parts with slotted walls. An intermediate duct 162 is closed at the bottom by the top wall of a duct 153, the side walls of which are spaced from the bottom wall which merges into the inner walls of the lower parts of the chamber C. The duct 153 is supplied with air from a separate pipe. Air ducts 147 formed at the lower edges of the short walls of the furnace deliver air at the sides of the chamber C. The rollers 81, 82 have studded rings 101 and rings of studs 104, and are driven hydraulically by crank-arms 107, Fig. 5, drive-rods 108 and piston-shafts 110 to oscillate through an arc of about 30 degrees. The upper and lower rows of rollers are driven by mechanisms at opposite sides of the furnace. Cooling water is circulated through the rollers and the flow is thermostatically controlled to maintain the temperature at boiling-point, separate steam and hot water outlets being connected to the rollers. Specifications 659,899 and 771,409 are referred to.