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Click on each thumbnail image	Cross section through "A" furnace. The skip hoist house is to the left of the furnace and a skip is shown at top and bottom positions. The skip dumped the charge into the breeches chute, McKee distributor, small bell, and big bell in sequence. The internal shape of the stock bins is shown and the scale car running on tracks 75ft1in. from the centre of the furnace. The coke (grizzlie) screens are just to the left of the scale car. The drawing suggests that there were three tracks for hopper cars on top of the stock bins.

	McKee distributor The McKee distributor was designed by Arthur G. McKee & Co. of Cleveland Ohio. The skips dumped into a fixed receiving hopper above the rotating hopper. This and the small bell revolved via a motor driven reduction gear driving a circular rack fixed on the cast steel plate carrying the hopper. The plate is supported by a ball race. The purpose of this arrangement was to promote uniform distribution of the burden within the furnace.
	Gas Off-takes The Replogle Steel Co. gas off-takes were an attempt to improve on the usual arrangement of very tall off-takes which restrict the passage of solids with the gas. These McKee designed off-takes diverted the flow of gas, with the least loss of energy, ejecting the dust out of the gas stream and into a trap from where it fell back down in to the furnace.
	Bosh and Hearth construction The coolers were accommodated in brick housings built in the lining, and in the plan view, the relative position of the coolers are shown. The bustle pipe, supplying air to the tuyeres via pipe couplings surrounds the hearth. Just at the tuyere level, an open water drain was arranged at intervals around the base of the furnace. Warm water from the coolers was led to these drains so that any potentially dangerous failure in the water cooling system was readily spotted.
	Cooler arrangement The cooling pipes coupled each cooler in groups of four, vertically. the coolers were wedge shaped copper castings with internal water channels. The bosh coolers lay horizontally in cast iron housings built in to the brickwork. The cast iron hearth coolers were arranged vertically around the hearth below the tuyere belt and were about 12 feet tall
	Primary dustcatcher The dustcatcher was a mild steel shell 25ft. in diameter with a conical bottom, domed top and refractory lining.
	Secondary dustcatcher Gas was directed to the secondary unit in a horizontal direction. the gas whirled around the outer casing which is 25ft. in diameter and comes in contact with a sheet of water, introduced just below the springing of the dome. the water curtain extended some 270degrees around the cleaner. A central tube was fitted to take off the clean gas.
$refractory.gif (39556 bytes)$	Refractory construction The machine-pressed bricks used in construction measured 13.5 in. long by 3in. thick by 6in. wide.

General construction notes.

The diameter of the hearth is 17ft. 6in., of the bosh 21ft. 6in. and of the throat 16ft. 10in., with a total height of 90ft. The ores used are magnetites and the usual burden contains 46% iron, giving an average output of 3290 tons per week.

The approximate weights of materials charged per week are as follows : Burden 7200 tons, Coke 3500 tons.

Good coke is available, and this, as well as all the ore, has to be transported by railroad. Stock bins are used for all materials, and scale cars are used for filling the skips. the charging gear consists of an inclined hoist carrying a double skip track. the skips discharge into a McKee distributor in which a small receiving bell is used, discharging eventually on to the large bell. The small bell with its hopper can be rotated. Owing to lack of space, the hoisting machine is arranged on the side of the furnace, remote from the hoist.

The bosh is banded with steel hoops (visible in the photo), the intermediate spaces being used to accommodate the bosh plate coolers. The hearth is protected with a strong steel casing inside which are fixed cooling plates 3 in. thick with water pipes cast in. The concrete foundation is brought up around the hearth and forms a further safeguard against break-outs. The working platform is provided by the top of the foundations, and is protected by a roof. Both iron and slag are dealt with in ladles.

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