The Mechanical Handling and Storing of Material

CHAPTER XIV CASTING MACHINES Casting machines are, to all intents and purposes, conveyors ■, they receive their load of iron in a liquid state at one terminal and deliver it at the other in the form of pig iron. The receptacles for the metal form at the same time the moulds for the pigs. The fundamental principle is that of a continuous bucket conveyor, built on lines to conform with the enormous duty they have to perforin, and as they deliver at the terminal only, the units or moulds are rigidly connected with the links of the two chains to which they are attached. Casting machines were first introduced in the United States and it is estimated that over 50 per cent, of the pig iron is handled by such machines. Of late years a few of these machines have been introduced into this country and the Continent. The chief advantages of mechanically casting and conveying pig iron consist in an enormous saving of labour, and also in the production of sandless pigs, as well as saving the large space occupied by the pig bed. In America such pig iron commands a premium of Is. to Is. 6d. per ton above pigs cast in the ordinary way, because melting more easily, it requires less fuel in the cupola. Mechanically cast pigs are smoother and cleaner, and of a more uniform size. Again, any waste in the casting process by runs of pig-bed scrap is avoided, while it is also claimed that such iron is more uniform and homogeneous. Further advantages are claimed in that the furnace can be tapped whenever it is most convenient, while the whole output is cooled and delivered into trucks without being touched by hand. One of the principal advantages, as far as labour is concerned, is the avoidance of the clearing of the pig bed by hand labour, which is exceedingly arduous, and in the hot season of the year the men are not infrequently overcome by it, but with the advent of the lifting magnet, which is used for this purpose with great success (see chapter on Grabs), the casting machine no longer monopolises this advantage. The disadvantages are that the iron suffers in fracture, that is to say it deteriorates in point of texture, which is due to the chilling effect of the mould and the subsequent submersion in water, as well as to the vibration of the mechanism during the solidification of the iron in the mould. (The chilling of the pigs may or may not have an injurious effect upon the later use of the iron, and it is believed that for steel making it is no detriment, but when the iron is bought by fracture it might affect its market value.) And lastly, the breakdowns to which such machines are subject. As yet only a few of these installations are at work in this country, the first being probably that erected in 1898 at the works of the Millom and Askam Hematite Iron Co., Millom, who adopted the “Uehling” machine, the use of which has, however, been discontinued. The second plant was that introduced at the works of the Palmer Ship- building and Iron Co., Jarrow-on-Tyne, who adopted the “ Heyl and Patterson ” machine. These two machines are similar in design, the principal difference being that in the case of the “ Heyl and Patterson ” machine the pigs are cast in moulds whilst partly submerged in water. There is also a minor detail in the device adopted for preventing the adhesion I7T