Patent GB-157950-A (GB)
Title: Improvements in and relating to furnace arrangements
IPC: F27B3/26
Filed: 1921-01-10
Abstract: 157,950. Corsalli, W. June 5, 1919, [Convention date]. Addition to 157,948. Void [Published under Sect. 91 of the Act]. Gaseous-fuel furnaces; regenerative fittings.- Comprises improvements in the furnace structure described in the parent Specification and in burners and reversing valves for use in connection therewith. The furnace shown in Figs. 14 and 15 is provided with two hearths 77, 78, used alternately for the preliminary and final treatment of the charge, and with outlet flues 76, 81, 82 for waste gases, the flues adjacent the burner which is in operation being closed by lids 83. When the burner 80 is in operation, air enters the reversing valve 87, passes through the regenerator 85, and by way of reversing valves 88, 89 to passages 94 leading to the burner which is also supplied with cold gas through a pipe 90. Part of the waste gases pass through the flue 76 to the valve 88 and passage 97 to the regenerator 84 and then through the passage 98, valve 87, and passage 99 to the chimney 86. The remainder of the gases pass through the flue 81 through the passages 100, 102 to the valve 89 and thence through the passage 103 to the chimney. When the burner 79 is in operation, the course of the air and gases is reversed. Several burners having flames of different length may be employed and they may be disposed at the sides as well as at the ends of the furnace. Fig. 13 shows a plan view of a furnace provided with a hearth 70 and outlet flue 72 for the gases. In addition to the ordinary charging-doors 71, doors 73 are arranged at the end of the furnace adjacent the flue 72 and serve for the introduction of further charges and removal of slags. Air entering through the doors 73 is drawn into the flue 72 and prevented from reaching the charge on the hearth during the smelting process. The reversing valve shown in Figs. 1 and 2 consists of a water-jacketted cylindrical bell 9 provided with a diarnetral partition which is adapted to engage with one or the other of two sealing troughs arranged crosswise between the segmental outlets of the flues 2, 3, 4 and 5. The periphery of the bell is provided with a flange 14 which dips into the annular trough 16 and the partition wall is provided at the bottom with a flange 15 which also dips into a sealing trough. The bell is supported on balls or rollers on a track 58 attached to vertically movable supports 59 provided with rollers 62 adapted to run on a cam track 63 on a rotatable table 52. When it is desired to change the valve from one pair of flues to the other, the table 52 is turned by a shaft 53 and the rollers are moved from their normal positions in recesses in the cam track 63 and effect the lifting of the bell through the supports 59. Upon further rotation of the table, pins 56 on the bell engage with the ends of slots 55 in the projections 54 of the table and effect the rotation of the bell. When the rollers again engage with the recesses in the cam track, the bell is lowered. Steam may be injected into the bell to prevent the formation of an explosive mixture of air and gas. Cooling water is supplied to the sealing-troughs by a pipe 17. The sealing- troughs may be water-jacketted and may be provided with inclined surfaces adapted to engage with corresponding inclined surfaces on the bell as shown in Figs. 5, 6, 7 and 8. The sealing- troughs may also contain sealing means such as water, sand, tar, oil, metal dust, or readily fusible metals or like materials. A horizontalflange on the bell prevents foreign matter entering the sealing-trough. One form of burner employed is shown in Fig. 9. It comprises tubes 65 supplying gas or air from a conduit 66 and passing through an air or gas conduit 67, the gas and air being discharged through the furnace wall. A " net " 69 may be arranged in front of the gas and air discharge passages to form a mixing- chamber and prevent back firing. The burner may be formed of semi-circular pipes as shown in Fig. 11. In the modification shown in Fig. 12, the burner tubes are maintained at predetermined distances apart by means of rods. The tubes may be crescent, scythe, star or zigzag shape in cross section and may be helical or provided with inner and outer ribs.