Weighing the Charge of Coke
Close weighing is necessary, for a variation of ten or fifteen pounds may affect the running of the cupola.
the castings being the three main determining factors.
Sectional View of a Cupola
When nearing the end of the day, charging ceases, the charging door is closed and the last charge, gradually descending, melts and flows into the bull ladle about an hour later. As soon as the bull ladle is emptied it is run out of the way, the cupola is drained of all iron and considerable slag through the tap hole, and the bottom doors of the cupola are dropped by pulling from under them the “props” which have held them in position. The great mass of bed coke follows with a great burst of heat, light and flame. This is quickly subdued with a stream of water and removed. When cool, the slag and accumulations are chipped from the cupola lining, burned areas are patched with bricks and stiff, fire-resisting mud, the bottom doors are raised and fastened in position, and the eight-inch sand bottom is packed in ready for the next day’s run. After building a fire and getting a good “bed” of glowing coke, the cupola is ready again for the charging of iron.
A Cupola in Operation
The stream of iron from the cupola spout flows into a “bull ladle” and from that into “shank-ladles.” The bull ladle serves as a reservoir and mixer.
Castings of Cast Iron as They Come from the Molds
The “sprues” have not been removed.