TABLE C.-CONTINUED. Per cent. of Water-Specific Gravity. Tempe rature. 1.102 103 104 105 106 107 108 109 110 C. F. 28/82-4 17.3 16.6 15.8 15.1 14-4 137 13.0 12.3 11.6 Mineral Produce of South Wales. On his examination before the committee of the South Wales Railway, Mr. Buckland stated that during last year, 220,000 tons of iron, and 600,000 tons of coal were exported from Newport, and from Merthyr to Cardiff no less than 180,000 tons of iron annually, and that this trade was increasing daily. From Newport and Cardiff, iron ores were exported in considerable quantities, and from the latter place. there was a large export trade to Ireland. From Bristol and Gloucester there were exported to Cardiff, in the year ending June, 1844, 80,000 tons, and from Cardiff to the other ports, 10,000 tons, which did not include coals. The total quantity of iron produced during the year in the district was from 450,000 to 500,000 tons, which, at the low average of 1844, was, 4,500,000l. in value. The tin plates produced in that part only of the district through which the proposed railway would pass, was between 27,000 and 28,000 tons, over 800,000l. in value. There were 55,720 tons of copper ore imported into the country last year, of which 43,734 tons were smelted at Swansea, the total value of which was about 2,000,000l. The whole metallic manufacture of the district amounted in value in one year to between 9,000,000l. and 10,000,000l., while there were large quantities of timber and charcoal produced in Herefordshire. Lond. Mining Jour. 29* Notice of the method of Puddling Cast-Iron at Montblainville, (Meuse,) by means of the combustible gases from a refinery fire. By M. SAUVAGE, Engineer of Mines. Trans'ated for the Journal of the Franklin Institute, from the Annales des Mines. The waste heat from refinery fires is successfully applied, in a great number of establishments, to various metalurgic operations, which do not require a very high degree of heat. At the time when M. Ebelman devoted himself to the important researches, which he has published, upon the composition of the gases which are disengaged from these furnaces, some unsuccessful attempts had already been made to carry on the operation of puddling by their aid. But it attracted the attention of M. Ebelman that a current of hot air, projected at the same time, through several orifices, (such as is now used for the combustion of the gases of a smelting furnace,) had not yet been used to burn the gases from a forge fire. This new application of waste heat has recently been the subject of numerous experiments at the works at Montblainville, and the operation of puddling is there practised in a manner sufficiently regular and advantageous to justify the belief, that it will be useful to publish the results. The refining fire, it is true, is not sustained by pure charcoal, but by a mixture of charcoal and a large proportion of baked or dried wood. The conditions, therefore, are not the same as in common refineries. General arrangement of the Apparatus. A, Is the refinery fire with two tuyers connected with one another. B, Working opening. C, Small furnace for heating the cast iron to be converted intɔ loupes in the refinery fire. E, Puddling furnace into which the flame from the refinery fire passes, after going over the main bridge wall T. D, Horizontal pipes which project air, previously heated to 300° C. (572° F.) into this flame, through 7 tubes or small tuyers, each 0.02 m. (0.79 ins.) diameter, arranged parallel to each other in the width of the furnace. This current of compressed hot air, burns the gases almost entirely in the space E, where the highest temperature is required. What escapes combustion passes with the other products of combustion, over the small bridge wall T, afterwards into the flue F, then serves to heat the cast iron for the next charge, and finally escapes through a low chimney (only a few feet higher than the roof of the works,) after having heated the blast in the apparatus H. This apparatus is arranged like that at Wasserhalfingin; it consists of nine straight pipes joined by elbows or bends; each pipe exposes 9-67 square feet of surface to the flame; seven of these pipes heat the blast for the puddling furnace, and the other two for the refinery fire. A small part of the waste heat is drawn off through a brick flue K, by a fan made of cast and sheet iron, and is driven into a pile or heap of wood to dry or bake it, for the use of the refinery fire. Method of Working. Refining. The cast iron used comes from a smelting furnace sup plied with dried wood and hot blast. The fuel is a mixture of nime parts by bulk of dried wood to one of charcoal. The wood is of va rious kinds, weighing in the forest, after being cut six months, from 2800 to 3000 lbs. per cord of 128 cubic ft. (350 to 375 Kil. la stere The product of the refinery consists exclusively of plough shares. The refinery fire has two tuyeres of 0.985 ins. diameter. The mean pressure of the blast is 1.57 ins. mercury = 0·77 lbs. per square inch, and its temperature from 176° to 212° F.* The manner of working is the same as usual; the workman charges with about 132 lbs. of cast iron previously heated in the furnace C; during the refining, properly speaking, he employs only dried wood, which gives to the refinery fire, a sufficiently high temperature for this phase of the operation, and to the puddling furnace a more aburdant and longer flame than the charcoal will make. As soon as the loupe is taken out of the refinery fire to be shingled, the workman fills up the furnace with about (2.47 cub. ft.) 14 heaped bushels of charcoal, covers this over with a little dried wood, and then puts in a new charge of cast iron. The use of charcoal at this period of the operation, is indispensable, in order to be able to heat the loupe, which will be brought back after shingling, to a white welding heat. The loupe is heated and drawn out under the hammer in the usual manner. The refining and drawing out of a loupe requires from one and a half to two hours. Puddling. The same cast iron is used in the puddling furnace as in the refinery fire. In commencing to work with the latter, the puddling furnace is gradually heated; the puddler prepares the hearth, and heats to redness a charge of from 374 to 440 lbs. of cast iron, in the furnace The time As soon as he judges that the furnace is sufficiently hot and that the hearth is ready, which is generally in about 4 or 5 hours, he places the cast iron which has been already heated to redness, in the puddling furnace, and puts another charge into the furnace G. The operation is afterwards conducted in the usual manner. required for one heat is about the same as for the refinery fire. The furnace works for 15 days without repair. The quality of the iron appears to be much superior to that made in the coal furnaces, under the same circumstances, and is more similar in this respect, to the iron made with wood. The formula Q =289 de✔h(1+0·0037 t 948 d' √h (1+0·00206 (t b + h 2.46 feet, 194° F. Q b + h or converted into English measures, Q= 32)), gives when d= 0·082 feet, h 0-1312 feet. b 1.66 cub. ft. per second, and for two tuyeres 3.32 cub. feet, at temperature of 194° F., and under a pressure of b + h 2.59 feet or 31-2 ins, mercury. The volume of air reduced to 32° F., add with the barometer at 29.85 ins, is 2-58 cubic feet. and per minute 155 cubic fect. The velocity of the air per second is 1.66 X 4 † Heaped bushel contains 2815-48 cubic inches. =312 feet. Drying of the Wood.-The fan, 1, receives its motion from the wheel of the blowing machine, by means of a cord and pulleys. It draws part of the gases from the furnace, through the flue K, and forces them into a channel built of stone, from 20 to 23 feet long, one foot square in section, and built under the surface of the ground. This channel is covered with cast iron plates, 16 inches wide, raised about four-tenths of an inch above the vertical walls, in such manner as to cause the gases to escape at the sides horizontally. The pile of wood to be dried, containing about 1400 cub. feet, or 11 cords, is arranged upon an eliptical base, of which the chaunel O, is the longer axis, and it is covered over with earth and cinders. The wood is placed so as not to touch the cast iron plates. The speed of the fan, and the position of the small damper S, are so adjusted as to maintain the pile at a temperature of about 392° F. After three or four days the wood is dried; it loses about 25 per cent. of its weight, and 10 per cent. of its bulk, and the color becomes slightly brown. It is in every respect similar to that obtained by the Echrement process, which we have before described.-(Annales, t.. xviii, p. 677.) Consumption and Products-Comparisons. = From the 1st of September, 1843, to the 31st March, 1844, the refinery fire working in the old manner, consumed 167-810 Kil. = 165 tons of cast iron, and 1060 met. cub. 23.002 heaped bushels of charcoal, of which one-seventh part is for loss in the store sheds (this) loss is real, and is verified by the experience of several years.) It has produced 1173 tons of plough shares, being 14.72 tons per month.* The consumption for each ton of plough shares has been 1-4 tons of cast iron, and 195 heaped bushels of charcoal. This consumption is great, but it should be observed that the plough. shares when taken from the refinery fire are only "roughed out," and it is necessary to heat them again, in a heating furnace, before being plated out, from which another loss is sustained; but the calculation of the consumption, the refinery fire is based upon the weight after being plated out. In April, this year, 1844, the apparatus was arranged as it is now; in May, June and July several changes have taken place in the work of the refinery fire, which has sometimes produced blooms (pieces cinglies) sometimes iron bars, sometimes plough shares; on the other hand the workmen have had to acquire experience in the new method; it is therefore impossible to have precise data for comparing the working of these four months with the preceding period. In August, 1844, the working was altogether regular, and the operation quite complete; the refinery fire consumed: And produced 144 tons of plough shares. This is an error, from 1st September, 1843, to 31st March, 1844, is but 7 months-the production was therefore 16.82 tons per month, instead of 14.72.-Trans. We use this unusual measure for wood in order that the relative quantity of wood and charcoal may be seen at a glance.-Trans. |