This may be cinch meted in various forms, that shown in Figs. 4, 5, (I, 7, and 8 having been used with success fur healing and welding iron. It is a radialion-furnnee, heated by means of a horseshoe-flame ; this form of flame offers advantages in this as in ordinary regenerative gas-furnaces, but its adoption is not obligatory, as the flame may be made to traverse the heating-chamber from end to end in the usual manner. The same letters indi cate the same parts in all the figures. A Al are reversible regenerators for air, on the top of which is built the gas-producer or converter B, of which F Fl are the charging-hoppers and \T 1" the grates. The heating-chamber E adjoins the producer resting on the ground, or in some eases a pit may be provided below it. CC' are the flues leading the combustible gas to the furnace-chamber E, the passage of the gas in these flues being controlled by the valves D DI at the two ends of a rocking beam, so that the outlets are opened and shut alternately to convey the gas to one or other of the ports G 0' of the heating-chamber E. H' are the air-ports of the heating-chamber, communicating through the flues K K.' with the regener ators A A'. I I' are steam-jets placed in the return-flnes L L' for directing a portion of the waste products of combustion to the grates of the converter. J is the valve for reversing the direction of the air flowing into the furnace, and of the products of combustion through the regenerators to the chimney-flue. 0 are hinged caps for alternately admitting and shutting off the products of combustion from the heating-chamber to the converter. These caps are worked automatically by means of connections attached to the rocking beam, the same move ment which closes D opening 0', and that which closes D' opening 0; Q q are doors for giving access to the grates of the converter for clearing them.
The modus operandi of the furnace is as follows: Gas from the converter B passes through the flue C' and the valve to the gas-port G', and into the combustion-chamber k' Air for combustion passes through the regenerator Al, the air-flue and the air-port /il into the combustion-chamber, where it meets the gas from the converter, and combustion ensues. The horseshoe-flame sweeps round the heating-chamber E, the products of combustion pass ing away by the second combustion-chamber k g, and goiII partly through the regenerator A and reversing-valve J into the chimney-flne, and partly down the flue 0. whence they are drawn by means of the steam-jet I through the capped inlet L under the grates of the producer B, there to be converted into combustible gases. From time to time the direction of the flame in the furnace is reversed by manipulating the rocking beam, carrying the valves D and the reversing-valve J in the usual manner of working regenerative gas-furnaces, An auxiliary steam-jet is provided for the purpose of supplying atmospheric air to start the producer when the furnace is first heated up.
The following advantages are claimed for the new furnace as compared with solid fuel furnaces used for heating and welding iron, viz.: A saving in fuel, amounting to, say, two
thirds in weight, after allowing for raising steam in separate boilers, this saving being fully equal to 5 cwt. of coal per toll of iron heated. A reduction in the waste of iron equal to 5 per cent upon the weight of metal heated. A saving in labor and repairs which will probably compensate for the extra cost of the new furnace.
The Pettibone-Loomis Open-Hearth Furnace (Fig. 9).—This furnace is designed for all kinds of open-hearth work using manufactured or natural gas, and is particularly effective with water-gas for very high heats. Gas and air are used under uniform pressure ; the former being conducted through the pipes a a' a' to the burners E, the air pass ing through the pipes J, where it is heated by the waste prod nets of the furnace, and thence through the pipes lo to the burners, where the two are thoroughly deliv ering a flame of great hiten sity tangentially into a round furnace. After circulating over the bath the products are taken out near the top of the hearth through the pas sage F and air-beater C to the stack. The burners are movable, and the flame can he directed on to the bath, or horizontally, as desired. The claims for this furnace are: 1. Low cost and durability. 2. Thorough and active combus tion of gas with application of beat to metal by radiation or contact. 3. Character, intensity, and volume of flame under control of the operator. 4. Economy of fuel and certain results.
Gas-Furnace for Melling Metals.—Fig. 10 shows one of many styles of furnace made by the American Gas-Furnace Co. of New York. This style of furnace is in use for gold, silver, copper, and brass. as also for making tests and smaller melts of iron, steel. glass, etc.
The combustion-chamber consists of the bottom A, and the cylinder B, both firmly secured to the distributing-ring C. The burners D penetrate the `• bottom " lining A. The bottom is held in position by the iron platform L. The cylinder B is secured to the distributing ring C by the hinged bolts 0. The cover 11 is hinged to the shaft It; so as to lift clear of the furnace-top when swung to either side. The •• feed-hole" in cover II is sufficiently large to give free access to the clueible without removing the cover, thus confining the heat while feeding the crucible. The small cover I closes the feed-hole. The crucible stands upon a conical brick support. Ily means of outlets for the products of combustion, both at the bottom and top of the furnace, the greater heat can (in a measure) be made to act either• upon die bottom or top of the crucible. When the vent (tti top is tightly closed, the greatest heat will be be low, while the partial (Telling of the cover I will draw it upward. Air under pressure is supplied through the pipe The tion of gas is according to the qual ity of the gas and the temperature required. The furnace shown in the cut will require from 200 to 2:50 cub. ft. of gas per hour, and melt 40 lbs. of copper in 30 min.