Page:Encyclopædia Britannica, Ninth Edition, v. 13.djvu/341

IKON iron is balled up, the quantity worked at once being sufficient to form several balls. Ehrenwerth s and AUeyne s furnaces are very similar in construction and mode of use ; in the latter the axis is hollow, containing a water pipe by means of which jets of water are made to play on the under surface of the upper bottom (the bottom being double), the water flowing away again through the hollow shaft ; in a later modification, a mechanical rabble capable of rotary or reciprocating motion is also attached. Pernot Puddling Furnace. This furnace essentially differs from the preceding ones only in that, while the revolving hearth rotates on an axis not perfectly vertical (as also previously used by Maudes- ley), the axis is mounted on a carriage, so that when required for repairs the whole hearth can be withdrawn. Fig. 62 represents the furnace with this modification that, instead of an ordinary fireplace being employed, a Siemens regenerator and Siemens gas producer are used in connexion with the Pernot hearth, the an angement being intended for steel melting by the Siemens-Martin process rather than for puddling (see 40). According to Petin (Journ. I. and S. Inst., 1874, 143) the fuel consumption with the Pernot hearth as compared with the ordinary puddling furnace is considerably less (the fuel being burnt in the same kind of fireplace in each case), whilst the loss in puddling is also less ; thus per unit of wrought FIG 39. Crampton s Revolving Puddling Furnace Cross Section and Sectional Plan. iron the following figures were obtained during the puddling of nearly 300 tons of fine iron and 50 tons of ordinary iron (leaving out of account the saving of labour) : Fine Pigs Ordinary Tigs Pernot Hearth (Pig used = 1021 (Coal ,, = 1-279 (Pig = 1-062 (Coal = 0-726 Ordinary Furnace. 1 060 to 1-070 1-770 1-120 to 1-160 1-170 Further experience has confirmed these results to a consider able extent ; thus the results of a year s working at Ougree in dicates that a yield of 1 part of puddle bars is obtained with a consumption of between 1 09 and I lO of the white Ougree pig and 075 to 80 parts of coal, or 04 less of pig and 20 less of coal than is consumed with the ordinary puddling furnaces in use there. The Godfrey and Hoivson Puddling Furnace. Like the Pernot furnace, this has a pan-shaped hearth rotating upon an oblique axis ; the obliquity of this can be adjusted to any required angle within certain limits, so as to admit of the ball being tilted out when the operation is over, the furnace bed having both a rotary and a tilting movement. The source of heat is like that of a Crampton s furnace, with this difference that instead of using coal dust a gas and air jet like a compound blowpipe of enormous mag nitude is employed. Details of the construction and working are given in the Journal L and S. Inst., 1877, p. 416 ; when the pig iron is previously melted in a cupola, it is said that a consumption of 2500 cubic feet suffices to puddle a ton of metal, this amount representing only about 5 cwts. of coal, the coke of which is not con sumed, and is consequently available for heating purposes. It deserves notice that in 1858 Oestlund invented in Sweden a revolving furnace almost identical in principle and mode of work ing with the Godfrey and Howson furnace of some eighteen years later date ; Jordan gives a description of this and some other Swedish early inventions in the same direction (Revue Univcrselle des Mines, torn. iii. No. 1 ; see also Iron, 1878, vol. xi. pp. 740 and 772). The following analyses.by Louis illustrate the changes produced during the puddling by hand of Nova Scotia pig : Time from Pe riod of cotn-J plete Fusion } of Pig Nil. Pig used. 8 Mins. Boil just com mencing. 13 Mir.s. Boil in vigorous progress. 18 Mins. Iron be ginning to drop. 22 Mins. Iron com pletely dropped. 40 Mins. and upwards. Final Puddle Bar. Iron 95-39 97-72 97-90 98-20 98-67 99-68 Carbon (total) .... Silicon 2-36 I ll 1-89 0-14 1-75 1-57 1-10 0-1(5 Phosphorus Manganese 0-36 0-78 0-25 trace 0-26 0-09 0-23 trace 0-23 trace 0-09 007 100-00 IUO on 100-00 id > 100-00 100-00 The following analyses indicate the character of various kinds of inder produced during puddling, reheating, &c. Particulars { Tap Cinder. Hammer- slag Iland- jiuddling Furnace, Nova Scotia. Refinery Cinder, Dowlais. Char coal Finery Cinder, Silesia. Cleveland Brom- ford Hand- puddled. Porous Cinder. Crystal line Cinder. ( Pig Puddled by Danks Machine. Analyst Snclus. Percy. Louis, j Riley. Riley. Karsten. Ferrous oxide Ferric Manganese oxide... 59-14 20 94 1-21 1-76 0-25 0-42 14-17 1-20 48-43 17-11 1-13 1-28 0-47 0-35 29-60 1-34 63-92 1507 3-18 1-51 traces traci s 14 -C9 1-60 65-52 1*57 3-60 0-45 1-28 25-77 1-37 0-23 54-94 2 : 71 1-19 050 3333 0-99 6 : 27 I 61-2 6-7 0-2 0-9 24 28 1 ". Lime Silica Phosphoric anhy-)_ dride ) Sulphur 6 33 Ferrous sulphide.... 1-61 99-42 101-32 99-97 99-79 99-68 99-5 1 According to the care bestowed by the operator, and the nature of the fettling and other circumstances, the amount of silicon,