Improvements relating to a method of and means for heating a one-way, horse-shoe flame fired furnace

摘要

836,992. Gas burners. STEIN & ATKINSON Ltd. March 16, 1956 [March 16, 1955], No. 8370/56. Class 75(1) [Also in Group XII] A method of heating a furnace comprises alternately increasing and decreasing the flame length independently of the firing rate. The method provides uniform heating of the furnace. In the soaking pit shown in Fig. 4 a large burner 45 and two small burners 46 supplied with an air/gas mixture are mounted on one wall of the furnace. The large burner 45 has a heat output substantially equal to that of the two small burners 46 and produces a long flame concentrating its maximum heat emission at the far end of the furnace. The two small burners 46 are short flame burners having their maximum heat emission at the near end of the furnace. The large burner is fired alternately with the two small burners. Three burners with equal heat outputs and delivering their maximum heat at the near end, the far end and the middle of the furnace may be used. Thermocouples may be mounted in the furnace for monitoring or for temperature or for safety overheat control. The burner shown in.Fig. 3 comprises two coaxial tubes 72, 73 fed independently with gas from a manifold 85a. Air is supplied by an inlet 71 to a burner body 67 surrounding the coaxial tubes 72, 73. The gas in the inner tube 72 flows into the furnace in a stream parallel to the air flow and produces a long flame. The gas in the outer tube 72 enters the furnace at an angle to the air now and produces a short flame. The gas supply to the outer tube 72 is controlled by a valve 90..which is opened and closed by a piston 94 operated by an electronic timer. The gas supply to the inner tube 73 is controlled by an orifice plate 88 or by a valve linked to the valve 90 in such manner that when one is closed the other is open. In a modification the gas is emitted from a single port and the air is delivered through either or both of two separate ports. The gas valve 90 may be controlled by the device shown in Fig. 7 and comprising a cam 105 rotated at constant speed, a pivoted arm 106, a housing 111 having valves 109, 110 and a diaphragm housing 122. In the position shown the valve 110 is open to allow atmospheric air to enter at 114 and flow to the diaphragm chamber 121. When the cam rotates to close valve 110 and open valve 109 air under pressure from line 112 passes to the diaphragm chamber 121. The diaphragm is thus moved backwards and forwards, as the cam rotates, and actuates the valve 90 through linkage 127. The cam 105 may be shaped to produce a constantly changing flame length. Reference has been directed by the Comptroller to Specification 779,145.