The Iron Age 1912-10-24: Vol 90 Iss 17

| Established 1855 THE IIRO New York, October 24, 1912 AGE Vol. 90: No. 17 Safeguards in the Eastman, Kodak Works Methods and Appliances Adopted in the East- man Photographic Materials Factories in Rochester, N. Y.—A Works Committee of Safety In keeping with its policy of conserving the health and safety of its employees, the Eastman Kodak Company, Rochester, N. Y., not only has provided numerous safety devices on both wood and metal working machines in the operation of which dangers are encountered, likewise enclosing belts and other moving parts, but has caused a committee of safety, organized for the purpose, to make a continuous study of conditions as they exist in the shops and also a study of accidents, of methods to avert accidents in the first place and of means to prevent Gear Hobbing Machine with Safety Guard and Casing Hand Milling Machine with Safety Guard EXAMPLES OF MACHINE SAFETY GUARDS IN WORKS OF EASTMAN KODAK COMPANY, ROCHESTER, N. Y. their repetition. The committee of safety consists of the managers’ of the five Rochester factories of the big pho- ‘ographic manufacturing company, and it investigates and ‘urthers the adoption of all practicable safety appliances in all of the: various factories of the company. The committee meets monthly and studies carefully all acci- dents which d6écurred in the preceding month. Its mem- ers offer any ideas or suggestions they may have con- cived or which have been originated by others, and these 951 are discussed, then tried out, and if found practical, are adopted. In the various factories there are sub-commit- tees whose duty it is to call to the attention of the management any machinery, apparatus or equipment that is not in safe condition or which is for any reason a menace to the operatives. The recommendations of the sub-committee are considered, and if found worthy, the necessary safeguards are installed. Accidents occurring in the Eastman factories are tab- ulated, together with the related data. The compilations Thread Rolling Machine without Safety Guard Thread Rolling Machine with Gears and Rolls Safeguarded show the number of employees in each factory, the num- ber and character of mishaps, the value of the time lost by the emplg@yee and the compensation paid by the com- pany. The accidents also are classified as to cause. In connection with compensation paid by the company after the occurrence of an accident, it may be said that the payments are made on a basis which is growing more and more uniform, although each case is still dealt with on its own merits. The company has set aside a fund of Guara for Buzz Saw $1,000,000, the inceme of which is being used in taking care of its sick and injured em- ployees and those old in the service. The number of accidents in the five Roch- ester factories per 100 employees during I9gII was 30 per cent. lower than in 1910, and the reduction is credited to the constant study of conditions and the resultant steps which have been taken to prevent accidents by means of safety devices as well as to an effort which is made constantly to stimulate in each employee a greater interest in his own and his fellow employees’ safety. At two of the company’s largest factories, emergency hospitals are maintained and full medical attention is pro- vided jn each case of injury. In the accompanying illustrations are shown a number, but by no means all, of the safety appliances in use in the Rochester fac- tories. Those used on the punch presses and puzz planers are manufactured by the Jones Safety Device Mfg. Company, Buffalo, N. Y., but all the others were designed by the me- chanical experts of the Eastman Kodak Com- pany. It is a notable fact that some of its keenest minds have turned their attention to Punch Presses Showing Safety Guard in Two Positions, Also Fly- wheel Guarded and Not Guarded THE IRON AGE Safety Counterweighted Lamp October 24, QI2 Guard Over Buzz Planer Knife the work. None of the safety appliances de- vised by the company has been patented, and this fact, as well as the details of construction, is freely explained to visitors to the plant Some of them are considered to be as near fool-proof as it is possible for a mechanical contrivance to be. As in the case of other manufacturers, when safety appliances were first installed, opposition was met with from some of the workmen, who maintained that the.safety pro- visions were “in the way,” that they impeded their work and were unnecessary with careful men of their kind, W. F. Folmer, manager of the Folmer & Schwing division of the com- pany, relates an anecdote of one testy but thor- oughly competent old sawyer who had been with the company for many years. He threat- ened to quit if the company continued to at- tempt to protect his hands and fingers. After an accident to another workman, however, the old journeyman said less against-the device in question and finally, after becoming used to it, he announced that he wou!'d quit if it were taken off his mache. Among the machines or moving parts on Automatic Press with Wire Mesh Guard for Gears and Plate Guard for Other Moving Parts tober 24, 1912 THE IRON AGE 953 ich devices preventive of in the Eastman factories cident have been placed may be mentioned the facil- band and buzz saws, ities which exist for pro- rtising machines, gears, tection against fire in Kodak vheels and belts general- Park, Rochester, which com- lathes, milling machines, prises about 72 acres and sses, gear hobbing ma- contains over 70 buildings, nes, thread-rolling ma- affording floor space of nes, bottle-capping ma- a nearly 40 acres, and housing ines, gasoline box tanks, oe about 3200 men and women eight elevators and incan- e employees While the escent lamp counter- : buildings are mostly of fire- ights. ‘¥ proof construction, the plant \n assurance against > has been amply provided ident in all the factories ae with fire-fighting equipment, the company. is the including 234 miles of indance of light from ; water mains for that pur- any large windows, while pose, with 37 hydrants, 4500 ie care has been taken of ft. of hose, 16 hose houses ntilation, all of which : Pe and an organized fire de- ids to maintaim prime . ; es partment of 8 members hysical condition and . having regular weekly drills. wakefulness on the part There also are volunteer employees. Cleanliness, Pan for Gasoline and Other Inflammable Liquids; Drop Lid Oper fire companies in the de- which is am essential in ated by Fusible Link partments, whose duty it is photography, starts in .the to see that employees are large group of Eastman factory buildings. drilled to leave the buildings promptly and in order in In conjunction with the precautions against accident case of fire. The buildings are equipped with sprinklers. Milling Machine with Safety Guard Belt Safeguarded by Rail and on Intake Side by Sereens Bottle Capping Machine without Safety Bench Milling Machine without Safety Guard Bottle Capping Machine with Safety Guard Bench Milling Machine with Safety Guard Caged SAFEGUARDS IN THE EASTMAN KODAK WORKS, ROCHESTER, N. Y. Se eh ee A en ts Bl i aN ie lip ee ene ee ier ane eee LY ete ce ve —Kn — ' t 4 4 ; The West Process for Sintering Flue Dust Elaborate Tests Showing Results of Different Methods of Preparing Fine Iron Before the days of Mesaba ore discoveries the blast furnace people were not troubled to any extent with the blowing over from the furnace top of quantities of very fine particles of iron-bearing materials, or flue dust. They had a comparatively loose, easy burden to work. The hard high-iron ores of 20 or more years ago gave them very little trouble in regard to this loss, now becoming greater as the percentage of the Mesaba ores increases in furnace burdens. Data gathered over a good many years show that the Mesaba ores themselves are becom- ing finer in texture. In those days very little was heard regarding slips, or hanging, or sudden loosening of the hot mass of material in the furnace, causing large quan- tities of very fine dust to be thrown out with the issuing gases. We did not hear of clean gas for the hot blast stoves and boilers; high heats were easily obtained on the comparatively clean surface of the brick checker work. In those operations the losses of iron ores charged into the furnace were not given very much thought, owing to their smallness. But the growing scarcity of these hard ores is compelling the use of more and more Mesaba ore until at present there are plants that are using all Mesaba in their burdens. To appreciate what this means to the furnace manager the following table of sieve tests shows how fine this mixture is becoming. , Group No. 1. Per cent. remaining on sieve: Through 2 8 20 40 60 80 100 100 27.50 26.69 15.19 10.72 481 3.19 1.84 10.06 26.00 28.53 ° 16.56 9.44 3.91 2.75 1.66 11.15 31.22. 25.09 .. 14.12 9.06 3.69 2.47 1.44 12.91 Ave... 28.24 ° 26.77 15.29 9.74 413 2.80 1.64 11.37 Group No. 2 25.87 20.87 9.27 9.92 8.24 4.27 2.84 18.72 29.06 19.82 8.05 9.52 14.78 95 1.16 16.66 21.59 21.69 9.98 11.86 9.05 30 3.87 16.66 Ave.. 25.50 20.76 9.10 10.43 10.69 50 2.62 17.34 wm we Group No. 3. 29.24 23.99 11.75 10.87 6.62 3.28 2.59 11.66 29.53 28.26 12.96 7.69 6.17 1.56 2.80 11.03 27.19 27.35 11.95 11.45 5.04 2.54 1.40 13.08 Ave.. 28.65 26.53 12.22 10.00 5.94 2.46 2.26 11.92 Group No. 4. 35.34 32.53 12.50 4.63 2.03 1.63 84 10.50 32.33 23.62 14.80 10.89 7.02 2.02 1.53 7.79 34.44 22.40 14.78 9.85 5.43 2.09 1.90 9.11 Ave.. 34.04 26.18 42.08 8.46 4.83 1.91 1.42 9.13 Group No. 5. 25.58 23.77 12.24 12.05 9.03 3.03 2.00 13.30 32.22 22.38 9:26 11.26 8.37 2.25 2.00 12.26 23.88 22.97 12.34 11.38 8.00 3.84 3.28 14.31 Ave.. 27.23 23.04 11.28 11.56 8.47 3.04 2.43 13.29 Besides the “group ores” there are a great many others that run just as fine, some as high as 24 per cent., through the 100-mesh sieve. The gas pressures on a blast furnace top may vary within very wide limits. There are some plants that will average 7 to 11 in. of water; others may go as high as 30 in. of water. Combined with pressure we have the up-rushing gases coming out of the mass at the stock line with great velocity and meeting the down-falling stock from the bell. A great deal of the material above shown will be caught and carried along by the momentum im- parted by the gases. This dust, a great deal of which is that passing through the 20-mesh sieve, as the tables above will show, is caught in receivers or settles along the gas flues. Some of the finest may be carried over to the hot blast stoves and boilers, depositing in these places and reducing the heat absorption of the apparatus. It is a *Assistant superintendent of blast furnaces, Works, Carnegie Steel Company. Edgar Thomson 954 Ores. for the Blast Furnace BY JAMES G. WEST.* - —— difficult matter to get entirely rid of this dust in the gases, and it is a rule that as long as there is motion in the gases some of the dust will be carried along. To get rid of this fine dust in these gases there have been de- veloped a large number of scrubbers, washers, cleaners, etc. Production of Flue Dust Computed To enable one to get an insight into this waste we will make use of some data extending over a period of eight years. These show that with blast furnaces using about 70 per cent. Mesaba ore and working under normal conditions, the dust is equal to 4 per cent. of the total materials charged. This includes ore, stone and coke. The average requirement of ore per ton of metal will be about 1.9 tons, that of coke 2240 lb., and of limestone 1000 Ib. Using these figures, we will construct the fol- lowing table, estimating the production of flue dust in the year IQII: Tons Pig iron production of the furnaces using Mesaba ore = 22,000,000 Tons ore used (22,000,000 K 1.9)....cceccesesccvece = 41,800,000 “stone (22,000,000 X 1000/2240) ' ........66- = 9,821,000 “coke (22,000,000 K 1000/2240) ........0.. = 22,000,000 SO kaiesids ae v edad ie eba ee keetéesae see 73,621,000 Average production of dust, 4 per cemt.........eeeee = 2,945,000 This can be placed at still a higher figure, for not over 90 per cent. of the total loss goes into the above percent- age. Of the dust coming over with the gases, 85 per cent. is caught in the large gas receivers at the furnaces and this is the material which will be spoken of at all times in this paper. Sieve tests of flue dust taken over a period of two years, all coarse coke being taken out before the test, showed the following: Per cent. remaining on sieve: Through 2 8 20 40 60 80 100 100 0.65 1.2 7.02 17.37 31.53 7.93 5.49 28.29 This test cannot be taken as a standard, because a great deal depends upon the regularity of the furnace operation, wind blown and nature of the ores used. Also some plants are screening the coke used, thus removing a large part of the breeze before the coke is charged into the furnace. Other plants are wetting their burdens very heavily. This also tends to reduce the quantity and also affects the quality of the dust. The softness of the coke used also has a great deal to do with the quantity pro- duced, a soft coke increasing the amount to a very con- siderable extent. The figures below represent sieve tests of dust from a blast furnace that was rolling or slipping: Per cent. remaining on sieve: Through 2 &-. 2 40 60 80 100 100 24.60 6.60 10.60 13.62 15,08 6.17 4.10 19.23 19.03 2.83 11.70 17.86 20.17 5.18 3.58 14.95 12.79 Si 4.88 8.84 28.20 10.00 6.79 27.49 As a rule the part of the dust that passes through the 20-mesh sieve is the most valuable, containing most of the iron ore. That part remaining upon the 20-mesh sieve is mostly stone, coke and pieces of ore low in iron and rather high in silica. For future use it pays to screen the dust through the 20-mesh sieve, if it is to be treated to increase the size of the individual grains or masses. ; Chemical Properties of Flue Dust These may vary as widely as do the sieve tests, but the following table is a good illustration of the dust, taking off all material remaining upon a 20-mesh sieve and from a blast furnace using 75 per cent. Mesaba ore in the bur- den. All fine coke dust was screened out before charging the coke into the furnace. “te yber 24, IQI2 Analysis of Flue Dust. Total SiO, Fe. Mn. P Mois AlsOs CaO. MgO. C. CO, S. 5.20 48.52 .39 .050 15.4 1.6 1.29 .30 4.71 ae ccce 5.49 43.31 .43 .032 166 1.5 1.33 .31 841 .10 6.99 48.56 .43 .038 148 22 145 09 468 .66 6.36 46.41 .46 .047 15.10 2.43 1.26 .48 3.67 .56 776 48.97 .38 .036 13.35 2.39 1.16 .42 3.73 81 9.58 47.09 .31 .035 13.65 2.05 DD cf. 7S ae v0 9.23 46.60 .48 .034 14.15 2.18 1.67 .31 4.48 1.00 .10 8.26 46.69 .70 .037 16.10 2.25 1.30 .34 3.04 .70 .12 7.22 48.03 .44 .034 14.45 1.65 1.41 .25 2.57 88 .10 9.46 47.16 .37 .036 14.80 1.97 85 .28 2.50 57 .07 9.23 46.43 .43 .034 11.80 2.07 1.37 .37 5.28 .83 .063 6.99 46.30 .47 .034 12.65 2.59 1.83 .45 7.41 1.60 .064 If a blast furnace is slipping or rolling heavily the total arbon in the dust may run up as high as 16 to 20 per cent. (he carbon contents of the dust play an important part n the treatment, either by heat or by mechanical opera- tions, which is employed to put it into various forms for recharging into the blast furnace. Most of the impurities, silica, etc., are combined mechanically with the iron; sep- ration by screening does not produce any great degree of oncentration. This also applies to the flue coke dust, the percentage remaining very nearly the same in all sieves under 20 mesh. Physical Properties—A Poor Heat Conductor The structure is' mostly in the form of grains that seem to allow large quantities of air or water to be ab- sorbed by any mass into which it may be shaped. It will hold approximately 25 per cent. of water by weight without separation. It approaches sand in its resistance to compression, remaining granular after subjection to enormous pres- sures. Experiments have been made where 25,000 lb. per sq. in. has been used and upon taking irom the mold, the heavy pressure having caused cast iron to be disturbed or swelled out, the dust mass itself would crumble easily under the touch. Any slight fall would shatter it into small pieces. It is a very poor conductor of heat; a very slight layer will act as an insu- lator, Fig. 1 illustrates this non-conduct- ing power of the particles. As may be noticed the rate of fusion does not exceed 1 in. an hour, and if the gases do not come in contact with all sur- faces of the mass the unexposed sur- face will not be heated thoroughly. * (Notice the bottom of all the masses.) The heat penetration or conduction may be increased in both rapidity and extent by subjecting the mass to a high degree of pressure before application of the heat. This is explained by the fact that pressure excludes the con- tained air and brings the particles of the ore closer together and if this Pp they conduct heat more rap- idly, Experiments make it self-evident that all particles of the material in masses must be subjected to the same degree of heat if the melting mass is to be uniformly cemented together. We cannot depend upon conduction to aid to any quick operation. Cementation starts very close to 2300 deg. F, Any temperature below this point only serves to change some of the other physical properties of the dust. Temperatures above this pro- duce close fusion or liquefaction. The degree of latitude between semi- ‘usion and liquefaction is very slight. This is aggravated ‘o a considerable extent if carbon be present. If too much arbon is present it tends to retard the fusion, until it is consumed by the heat; and if the mass is withdrawn be- ‘ore the coke or carbon is consumed, there will be no ‘usion of the ore particles, the resulting mass being very eTainy in structure. THE IRON AGE Magnetic Properties The magnetic properties vary a great deal in the differ- ent kinds of dust and depend on the temperature of the furnace top from which they were produced. About 60 per cent. of the total iron, as shown in .the chemital analyses in the foregoing tables, will be magnetic. By exposing to heat at varying temperatures it has been demonsirated by repeated tests that this percentage may be raised. Table Showing Per Cent of Magnetic Material in Fine Dust at Varying Degrees of Heat. Per ct. Ign. Car- Orig. Temp. SiO, Fe AlkO,s CaO MgO Loss bon sample Mae... i. 75 deg. F. 4.04 63.65 2.81 .20 .10 None 1.80 68.80 Non-Mag 11.26 36.95 1.85 2.26 .10 25.65 20.55 31.20 Mag..... 200 deg. F. 5.71 59.45 2.18 .51 .10 3.61 2.70 72.85 Non-Mag 11.18 35.80 3.00 2.75 .36 26.86 14.40 27.15 Pek ce 400 deg. F. 4.02 62.60 2.27. .18 .60 79 2.00 73.85 Non-Mag 10.01 36.25 2.86 2.24 .10 26.21 22.20 26.15 Mag..... 500 deg. F. 3.89 62.85 2.08 .13 .32 None 1.90 78.80 Non-Mag. 9.88 41.50 2.90 1.79 .10 20.73 48.30 21.20 By continual heating for some time at a temperature about 1500 deg. F., about 84 per cent. of the total iron in ordinary flue dust can be rendered magnetic. The impurities in the dust may be eliminated by mag- netic separation, either by the wet or dry methods, or by specific gravity. Either of the first two methods will Haro Fveeo. Semi Fveco. Raw Over. Fig. 1—Degree of Heat Penetration in Flue Dust Masses, 6 x 6-in. by 2, 4 and 6-in. Thick recover only about 60 per cent. of the iron in the original dust, for as shown before all the iron present may not be in the form of magnetics. Below is given the performance of a magnetic separator on blast furnace fiue dust, the iron and carbon percentages being shown for both mag- netic and non-magnetic portions. Six different lots of flue dust are represented in the table: See ‘ sete -—Magnetic Portion—, —Non-magnetic Portion— fron Carbon Iron Carbon Per cent. Per cent. Per cent. Per cent. Ne: $...ssa.% 60.83 3.23 33.87 27.08 Diag iis x’ ccecitcn 59.51 4.21 43.74 16.40 ae ER 64.15 2.15 43.59 15.08 Ne, Accnsicas 57.40 6.16 42.43 17.05 NS 64.95 2.75 48.58 10.70 Os Diaceens 63.70 3.99 45.91 12.70 For briquetting by pressure and heat, lower carbon content is desired. The specific gravity method consists of passing the dry dust over a shaking porous bottom, ai V v t Yn Y Ya t RMAMOO@Oo2_iuiusn7» Fig. 2—Longitudinal and Cross Sections of the West Sintering Furnace. being forced upward. This makes the lighter pieces of iron-bearing material and the coke dust rise to the top, where it is taken off by riffles to the side, the heavier material going one way and the lighter stuff in another direction. For this class of work this method gives de- cidedly better results. All the iron may be recovered if desired, or if a high iron content in concentrates is de- sired a small portion of iron will have to be sacrificed. In briquetting by pressure and heat the rule has been to combine these two methods, taking all the magnetics out that is possible, and then passing what remains over the specific gravity machines. Table Showing Work of Specific Gravity Machines. Tailings from - Specific Gravity Magnetic Separators. Concentrates. Tailings. Fe i CO, Fe c CO, Fe a CO, 38.30 22.12 1.81 44.60 8.91 2.75 21.4 46.35 1.58 45.40 11.89 1.38 49.50 9.43 1.65 28.8 31.69 1.89 37.70 16.25 2.10 47.50 10.65 2.12 253 37.95 1.65 40.60 14.98 1.65 47.20 6.42 Dee. | nibcen esis ns Ave. 40.50 16.30 1.70 47.00 8.60 2.30 25.2 38.70 1.70 By this combination of magnetic and specific gravity machines the iron loss for ordinary work may be only 10 per cent. In case a high iron content is desired, the specific gravity machine is far superior on this dust Where high iron is desired the dust is classified by screen- ing to give the best results, although screening or sizing may not at all times be necessary for obtaining certain desired results. Some of the results with specific gravity machines are shown in the following: Carbon, Per cent. Iron, Per cent. 2.66 64.05 3.62 61.52 4.93 60.42 3.45 62.03 2.72 62.84 2.49 62.53 1.51 63.04 Further adjustments in this specific gravity machine have produced even lower carbon contents. There have been numerous attempts to use flue dust in a Taw state. The majority of furnacemen would express a negative voice if they were to be asked the advisability of its use. A notable exception to this rule is the practice at the Ohio Works of the Steel Corporation. At this place it has been used for some years and with telling results. The tendency of the times are toward a treatment of some kind whereby the size of individual grains or masses will be increased. Methods of Treating Flue Dust Numerous methods have been practiced in treating the dust. All these come under the following divisions: 1. Mechanical pressing, with addition of some foreign substance to aid in holding the mass together. 2. By mixing the fuel with the material to be treated, THE IRON AGE . October 24, 1 igniting, and forcing air up or down, throwing the 1s; lying upon a porous bottom. . 3. Rotary kiln. 4. Briquetting by pressure and heat. 5. Exposing a large surface of the dust to the action of the flame and addition of fresh material as fast as it will form an agglomeration. The physical properties of all these methods differ greatly, and the object aimed at should be kept in mind before any one is selected. The considerations are: Methods of handling the product, distance te be transported, whether the product is to be stored or sub/ected to the action of the elements, etc. A redivision of the process, according to the physical properties of the product would be as fol- lows: Processes producing lump masses of considerable size No. 4.—Grondal process. No. 5.—West sintering method. No. 1.—General briquetting process. Processes producing a porous mass: No. 2—Greenwalt, Dwight-Lloyd, Brown, Grasselli, etc Process producing small lump masses: No. 3.—Rotary ki!ns. All of these methods are in operation with varying output. For the treatment of flue dust, briquettes by heat and pressure are probably producing more tonnage than any of the other methods, and a great many experiments have been made to adapt the apparatus to the peculiarity of the dust The West Sintering Apparatus All the processes above named have been before the public for some time, with the exception of the West sintering method, which was patented by the Carnegie Steel Company in behalf of the writer, and which was the logical outcome of the production of lump masses for the blast furnaces as well as the open hearth, at the same time reducing the preliminary treatment of the dust to remove the carbon, by concentration (when it is desired) and pressing, to produce a mass that would have great strength and density, and stand a large amount of handling and weathering without serious deterioration. The invention consists of a furnace with a movable bottom, on which a block of the material is built as fast as the continuous action of the heat will agglomerate or stick the particles together. The material can be delivered to the furnace in several ways: 1. Letting it fall from the roof and spreading out mechanically to form a thin layer. Fig. 3—A 20-Ton West Sintering Furnace tober 24, 1912 Using a kind of injector operated by air, moving er the area. Using a type of continuous furnace with the bot- noving slowly along, the dust being charged in defi- places. all these methods we get a very thin layer of ma- 1] subjected to heat, which softens it before another itity is added. In any of these methods the charging be so timed as to make the addition of the dust st continuous. By the West method crude dust can andled without regard to its peculiarities, and a very rable product obtained. It does not require pressing, ntrating, etc., as in other processes, to produce lump s. After the block or mass is built up to the capacity furnace it is withdrawn and the sinter removed by ns of a crane; it is then broken to sizes that may be If this breaking is done while the mass is red t there will be a minimum of effort and cost. if able. Construction of the Furnace Figs. 2 and 3 the construction of the furnace used e West sintering method is shown. The flue dust is irged in a fine stream through an opening in the roof the furnace, and is so highly heated that the particles re form a thoroughly sintered layer immediately upon hing the hearth. In falling the finely divided solids brought into intimate contact with the gases. The rnace consists of a roof and sides, with a longitudinal lt or passage through which the trucks carrying the able hearths may pass. The sides of the furnace are equipped with burners, A. Passages B in one side of the e connect with the stack. Extending vertical'y gh the roof is the opening C. The hearth D is de of suitable refractory material, supported upon the E. Each furnace is provided with several such ks with the hearth prepared ready to be pushed into furnace vault. rac In operation, a layer of the fine ore or flue dust is laid ipon the hearth, to a depth sufficiently thick to insure that he ore will not stick to the refractory bottom, the thick- ss of this layer being sufficient to prevent it being entirely eated to a plastic state. The furnace bottom is further repared by building a wall F along the marginal edges the top surface of the hearth. Refractory clay or brick ire employed for this purpose. When the hearth has thus en prepared, it is moved into the vault of the furnace ind curtain doors are lowered to cover both ends of the iult. The burners at the side of the furmace are then lighted and the furnace hearth or bottom is heated to the esired temperature, after which the sintering operation egun. Chemical and Physical Characteristics Below are given results of analyses of flue dust and West sinter, also the percentages of various sizes of ‘riginal material and the percentages of three sizes of resulting sinter : +—Large Lumps of Sintered Flue Dust, the Product of the West Process THE IRON AGE 957 Fig. 5—Piles of West Sinter at Blast Furnace Analyses of Crude Dust and Sinter Crude Dust. Sinter. —Per cent—, -—Per cent—, Silica 8.77 13.50 DR : <dxtoleéet 9.60 8.50 DN ogee ence 47.19 49.50 lron . 64.20 66.20 Phosphorous 0.032 Manganese 0.56 Manganese 0.38 Phosphorus 0.049 Moisture 12.75 Pele ass ccuwans 3.36 GRP? teecaes 2.16 MeO 0.54 See vase 1.79 CaO 0.51 Carbon 10.20 Sulphur ....... 0.12 Sulphur 0.05 PURP tcisavenias POR cicnenans Kw Carbon 0.34 Percentages of Dust on Sieves, with Size of Sinter. Through 2 8 20 40 60 80 109 100 Before treatment. .65 12 7.02 17.37 31.53 7.93 5.49 28.79 Pet cent. Percent. Per cent. %-in. 2-in 5-in. After treatment and unloaded at fur- militia . GEM, oo 6 cvs noted ead bvtaewetes 1 5 a4 In cases where it was desired to make as large lumps as possible we have some of the following figures: 8x6x7 Wiisicaseves takue useetnens 64 Ib. net. 8x6x2 is. Wa eeabet cektbenaeun a ” 7x4x3 Dive 6tieese ve sacscvevesapes = _ 8x5x3 DLs died nie réake ieee nes 4 S 6x7x2 PAP s rac 60:9 0d a beeaenal ae 4 7x5x4 Oe ck eae is ae ani tele ee ” 7x5x3 Bhictccaduesineies ane éaean eo 8 7 2 $2 Se Oe co tccoteesenesecsvincatiée > - 7 OES BBs co Fada kcssseveccnsmusate The iron in these lumps averaged 65 per cent. As the operation is under complete control at all times the re- sulting product may be either dense or porous; but at all times will there be a great deal of strength. The table below shows the properties of product made from flue dust by heat and pressure and that produced by the West method : Heat and Pressure. Sinter. Per cent. Per cent. Ager ptION © vnc bc receccsosesussawe 15.0 6.9 POO ain. ddcdcncdcecdvosnenvas 37.0 18.9 Specific gravity.....--..scecescesere 3.9 3.2 Apparent specific gravity.........-.- 2.7 2.6 The chemical content of the product from this process, compared with that of some of the others, may be seen from the following table, crude dust being used at all times : Rotary Porous --Heat and Pressure, -——West Sinter—. Kiln. Product. Iron .. 61.4 61.7 9 65.7 644.2 662 5807 58.3 Silica .. 90 8.2 9.2 9.7 9.6 8.5 10.68 11.3 Experience with Sinter—Cost of Plant Under this method of production we have a superior Semeran nina eiitipr tale weit alee tarine “ > one . * Fee i nin wegen ~ arr cg mde pee Be OTS Ge Oe la a Re rere are ge cogoagagel ae wae 958 THE IRON AGE type of apparatus in which the heat degree can be kept practically constant and even over the whole surface of the mass, very little dependence being put upon conduction to do the work. This is very important, as was shown under the description of the physical properties of the dust. It is necessary regardless of the form of apparatus to have the heat distributed as widely as possible through the mass to be sintered. The product of the furnace shown has been used on blast furnaces with good results and did not seem to in any way disturb the regular method of operating. As high as 30 per cent. of the total ore burden has been withdrawn and an equal amount of sinter substituted without any derangement of required results. With the growing scarcity of low silica, high iron ores for open hearth use it is becoming recognized that a sub- stitute must be found. To this end the dust is concen- trated, pressed and sintered into lump form. The tests using lump masses have given excellent results. Dense sinters from the pits have also given good results. The estimated cost to operate the various forms of briquetting and sintering apparatus is as follows: Porous Rotary Heat and Product. Kiln. Pressure West. PEs tick donkieeene $0.05 (a) $0.39 (c) $0.35 (c) $0.25 (c) Labor operation... Labor repairs..... 45 61 1.25 25 Material ...0..s0s% All other costs.... Be sins $0.50 (b) $1.00 $1.60 $0.50 (a) Gasoline cost for igniting fuel. (b) Metallurgical and Chemical Engineering for September. (c) Coal at $2 per ton (12,000 B.t.u. per Ib.) The cost of installing per ton day of 24 hr. in large plants is as follows: IS 0 ws os ood vole ns sauede Gawsell $150 Oe aos cCosic cans orc hes nt wetweeee 300 in 5 aend ata bp ap sb eau 400 ee Sins ass ob bh hiee «oa 5 AS 100 If in proximity to natural gas or crude oil the last- named figure could be reduced to $80. Where blast fur- nace gases could be used the cost of the last three would be considerably reduced. Our Coal Output Doubles Every 10 Years An interesting fact in connection with the production of coal in the United States, according to the United States Geological Survey, is that in each successive decade the output is practically doubled. If the production of bituminous coal alone were considered, the record for the last 50 years would show an increase somewhat in excess of this ratio. The increase in the production of anthracite has been much less rapid on account of the limited area of the fields, the conditions under which the industry is carried on, and the restriction of the prepared sizes to domestic consumption. It has been estimated that the output of anthracite will reach 100,000,000 gross tons an- nually before it begins to decline. The maximum pro- duction up to the present time has been 80,771,488 tons. The statistics of coal production show that up to the close of 1865 the total output had amounted to 284,890,055 net tons. In the decade from 1866 to 1875, inclusive, the production amounted to 419,425,104 tons, making the total production up to the close of 1875, 704,315,159 tons. In the following decade, from 1876 td 1885, inclusive, the output amounted to 847,760,319 tons, somewhat more than double the total production in the preceding decade. At the close of 1885 the total production amounted to 1,552,075,478 tons. The production in the 10 years ended in 1895 was 1,586,098,641 tons, the total production at the close of 1895 amounting to 3,138,174,119 net tons. In the decade ended December 31, 1905, the total pro- duction amounted to 2,832,402,746 net tons, and the grand total from the beginning of recorded coal mining in the United States amounted to 5,970,576,865 tons. The average annual production from 1896 to 1905 was 283,240,275 net tons; the average production from 1906 to 1911, inclusive, was 461,499,260 tons, showing an in- crease of 178,258,985 tons, or 63 per cent. October 24, i912 Automatic Fire Protection Demonstrated An impressive demonstration of automatic fire protec- tion is being shown by the General Fire Extinguisher (om- pany, Providence, R. I., at the water conservation exhibit being held in the court yard of the City Hall, Philadelphia, Pa., under the direction of Morris L. Cooke, director of public works, and a committee appointed by Mayor Rudolph Blankenburg, of which H. W. Benjamin, of the water bureau, is chairman. The automatic fire protection exhibit, a photograph of which is here reproduced, consists of a 10 x 10 x 10 ft. De- troit Fenestra steel-sash building, with a roof of the same character, surmounted with a Drouve ventilator. Wire glass windows made by the Mississippi Wire Glass Com- pany, are used in the sash. ‘Che bottom of the building js covered with asbestos board and a pyramid of the same material, 2 ft. square at the base and 3 ft. high, is erected in the center. Above the pyramid is suspended a single Grinnell automatic sprinkler with a fusible link, adjusted to melt at 155 deg. and operating under a water pressure of 75 Ib. In making the demonstration of the device, the pyramid and base are saturated with alcohol, strontium salts be- ing added to produce a color effect when the alcohol is ignited. A lighted match is thrown into the booth and it has been demonstrated that 15 sec. after the alcohol is ignited the temperature rises to the fusing point of the link, opening the sprinkler, and in 15 sec. after the sprinkler begins to operate the fire is quenched. In addition to the demonstration by the sprinkler there is shown in operation in connection with the same, the Grin- nell straightway alarm valve, which provides a means of Educating the Public in Philadelphia in Regard to the Automatic Fire Extinguishing Sprinkler giving notice that a fire is in progress. Through the alarm valve the water supplied to the sprinkler must pass. The flow of water operates to close an electric circuit which operates alarm bells, located at desirable points. The device provides for the variation in water pressures, so that by any unequal pressure operating on the valve, the possi- bility of a false alarm is avoided. The exhibit will be con- tinued through October, and demonstrations are being given every 15 min. for the greater part of the day and evening, The Society of Chemical Industry, New York Section, will hold its next meeting at Rumford Hall, 50 East Forty-first street, New York, on Friday evening, October 25. Prof. M. T. Bogert, president of the society, will review the life and work of the late Dr. Morris Loeb. James B. Douglas, manager, and J. F. Conner, assistant manager of the claim department, United Gas Improve- ment Company, Philadelphia, will describe and demonstrate the system of rendering aid to men injured, suffocated, overcome by noxious gases, electri¢ shock, etc., as de- veloped under their personal direction and as applied in the plants of the U. G. I. throughout the United States. ctober 24, 1912 Gasoline Engine Electric Generating Set A self-contained gasoline electric generating set has , developed by the B. F. Sturtevant Company, Hyde rk. Mass., to meet a very widely varied demand for its of small power. e special purpose of set is to generate rrent for lighting d power in localities here public facilities e absent, but the field much more general than this, and includes sower for small manu- facturing establish- ents, on ships and as ixiliaries in large ower stations. Fig. 1 a view of the set, while Fig. 2 shows the special design of cen- trifugal vertical throt- ing governor em- ployed. The set consists of , standard Sturtevant generator, direct-con- nected to a gasoline en- gine which has been de- signed recently by the ompany’s engineers. It is of the four-cycle, water-cooled vertical type, with either four or six cylinders, ac- cording tu the size of the unit—5, 10 and 15 kw., capable respectively of lighting 200, 400 and 600 20-cp. tungsten lamps. A long stroke engine was chosen as the most efficient for the service. Both engine and generator are capable of operating under an overload of 25 per cent. for 2 hr. The bore of the cylinders of the two larger sizes of engine is 4 in. and the stroke 6 in. while the 5-kw. machine has a 334-in. bore and 5-in. stroke. The cylinders of the larger sizes are cast in pairs, having T-shaped heads with inlet valves on one side and exhaust valves on the other. In the small unit the cylinders are cast en bloc with inlet and exhaust valves on the same side. The water jackets are all integral. Great pains has been taken in the selection of materials and in the design of pistons, crankshaft, cam- shafts and the other work- ing parts. An improved system of forced lubrication is used, insuring perfect oiling of all moving parts and bear- ing surfaces, and permits their continuous operation for long periods without adjustment. The system is automatic and self-con- tained, requiring no sepa- rate tanks or outside pip- ing. A geared pump, lo- cated in the base of the en- gine, furnishes oil under 20- lb. pressire. It is gear- driven from the camshaft and is positive in operation. The oil enters the main bearings and flows through the crankshaft to the crank pins, whence it passes up the connecting rods to the piston pins. The oil spray thrown off by the centrifugal ac- tion of the crankshaft covers pistons and cylinder walls. Oil under pressure is also supplied to the camshaft and gov- ernor bearing. The oil falls back into the base, where it basses through a filter before being used again. The base soul sufficient oil for 50-hr. continuous use without re- newal. Fig. 2—The Special : Centrifugal Vertical Throttling Governor Used Type of THE IRON AGE 959 The engine is controlled by a specially designed throt- tling governor of the centrifugal type, Fig. 2, operated through bevel gears from the end of the camshaft. A ball bearing between the regulating spring and the gov- ernor balls permits the spring to remain stationary and Fig. 1—The New Gasoline Engine Electric Gencrating Set Built by the B. F. Sturtevant Company, Hyde Park, Mass. allows adjustment of the governor to be made while the engine is in operation. The motion of the governor is transmitted to the throttle valve placed in the inlet mani- fold. The design is such that the governor will control the speed of the engine to so close a degree of regulation between no load and full load that voltage variations due to sudden changes in load are practically imperceptible, and therefore no storage battery is necessary to maintain a constant voltage, the generator supplying current directly to the lighting or power circuit. ' Concrete Highways The latest development in securing good roads is through the use of concrete. This new type o7% road is now the subject of extended experiments by the United States Government. It has met with such pronounced suc- cess in Wayne County, Mich., as to give that locality na- tional celebrity. In brief, a concrete road is akin to ce- ment sidewalks, being a water-shedding, indestructible monolithic mass. The Association of American Portland Cement Manufacturers, Land Title Building, Philadelphia, Pa., has published for free distribution a comprehensive book entitled “Concrete Highways,” prepared by expert road engineers, which goes into every detail of construc- tion, concluding with a tabular digest of concrete pave- ments in all sections of the country. The book, which is handsomely and profusely illustrated, contains nearly 100 pages. The various chapters treat of bituminous com- pound wearing surfaces, grouted pavements, reinforced concrete pavements and specifications for the one and two-course types. Road supervisors will find it of espe- cial value, while the taxpayer will be extremely interested in the economical results obtained by the introduction of these durabie concrete highways. The Iron Trades Employers’ Insurance Association (Ltd.), is the largest mutual society in Great Britain un- dertaking employers’ liability insurance, and its experience therefore supplies a measure of the risk in respect of an important class of trades. From the annual report re- cently made public it appears that the premiums received during 1911 amounted to $1,094,417. Claims are given at $824,210, and expenses were $76,092, or 6.95 per cent. of the premiums. There is thus a substantia] margin as a result of the year’s operations. j 960 THE IRON AGE Improved Open Side Grinding Machine For grinding pieces such as railroad frogs, switches and crossings, safe and vault parts and other similar articles made of materials that are not workable with steel cutting tools, the Detrick & Harvey Machine Com- A New Open Side Grinding Machine of the Planer Type Built by the Detrick & Harvey Machine Company, Baltimore, Md. ’ pany, Baltimore, Md., has designed a grinding machine of the open side planing machine type. The machine which is said to have proved particularly efficient for this class of work consists of a regular type reciprocating table, bed, post and cross-beam of the builder’s standard open side planing machine, which was illustrated in The Iron Age, August 15, 1912. Instead of the ordinary cut- ting tools, however, a grinding wheel carried in a saddle which can be fed up or down or longitudinally or trans- versely with reference to the bed of the machine has been substituted. The grinding wheel is driven by an independent motor, mounted on the same saddle through a belt drive, and the wheel can be mounted on either side of the spindle, which is made of steel and has a carefully ground fit in long bronze bushings. The saddle carrying the wheel and the motor has a sliding fit on the cross-beam and can be traversed across it by hand operation from either side, the power feed screws having ball thrust bearings to in- sure easy operation. If desired, however, a power cross feed can be attached. The cross-beam of the machine is carried on the face of the post with a sliding fit, and can be fed up or down by hand or power, as may be desired. A counterbalance renders this adjustment easy. The table is gibbed on the side next to the post, and is operated by a spiral pinion and rack. The motion can be controlled from either side of the machine, the reverse movement being obtained by shifting belts. The drive of the table is through a countershaft mounted on the post. The table speed is 50 ft. per minute in either direction, and is operated independently of the grinding wheel. The machine is made in two sizes. The hight of the work accommodated in both cases is the same, 18 in., but the maximum widths are 48 and 56 in. respectively. The length of bed can be varied within reasonable limit to suit the requirements of the purchaser, the machine illus- trated in the accompanying engraving having an 18-ft. bed. The grinding wheel used on this machine is 18 in. in diameter, has a 3-in. face, and runs at a speed of 1300 r. p.m. The weight of the machine is 59,000 Ib. The annual meeting of the National Metal Trades As- sociation will be held at Hotel Astor, New York, Wednes- day and Thursday, -April 9 and 10, 1913. The dates were chosen by the Executive Council which met in New “York last week. October 24, iyi2 A Blast Velocity Gauge for Cupola* BY P. MUNNOCHT The most simple form of apparatus which can be used to measure the velocity of air passing through a blast tube is the Pitot tube and gauge. The foundryman with this instrument can obtain some idea of the amount of air being used in the cupola and thus obtain figures which will have some comparative value when compared with cupola performances from time to time. As an index to the rate of melting, it should at least be of more value than the ordinary pressure gauge with which practically all cupolas are fitted. The pressure to be measured is very small, usually below ™% in.. water pressure; therefore some means of magnifying the sma!l movement of the column of liquid is necessary. The most simple way of doing this is to incline the gauge tube. If water is used in the gauge tube an inclination of one in ten from the horizontal increases the travel of the water column by five times that obtained with the gauge in a vertical position. Water is not satis- factory owing to the sides of the tube becoming dry and resisting the movement of the liquid and _ also preventing it from returning to zero after being in use. Common kerosene is more suitable, but as the specific gravity is less than that of water a greater inclina- tion to the hori- zontal is necessary to give the same five-to-one travel. With kerosene of 0.795 specific gravity an inclination of one in 7.95 in. is’necessary. Instead of the inclined tube, some form of differential gauge may be used for increas- ing the magnitude of the readings; where a portable gauge is required this type of gauge is more suitable. There are two forms listed in chemical catalogues. For the purpose in view a scale can be constructed from which we may read off either velocity or quantity in cubic feet per unit of time, one second being a suitable unit. The accompanying table shows velocity in feet per second for different indications of the water gauge. With blast pipe of 1 sq. ft. area the readings would indicate cubic feet per second. Water gauge Velocity in Water gauge Velocity in in inches. feet per second. in inches. feet per second. 0.006 5 0.295 35 0.024 10 0.386 40 0.054 15 0.498 45 0.096 20 0.603 50 0.150 25 0.740 55 0.217 30 0.869 60 The inclination of the gauge tube multiplies the move- ment of the liquid five times; the Pitot tube described, having one limb operating by pressure and the other by suction, multiplies the movement by two, the net resu!t is that the movement of the liquid in the gauge is magni- fied ten times. Tenths of an inch on the scale will there- fore represent hundredths of an inch, and scale to read in cubic feet per second is calculated and marked off to correspond. To obtain an average reading, the Pitot tube is inserted from one-sixth to one-fifth of the diam- eter into the blast pipe. It should also be inserted in a straight length of pipe, as far as possible away from bends. The New York State Steel Company, Buffalo, N. Y., is repairing its open-hearth plant with the purpose of starting operation on billets and blooms about November 1. As soon as present contracts for foundry pig iron are completed, the company’s blast furnace will be changed to the production of basic for its own use. *From a paper entitled “Air Required for Combustion in the Cupola, and a Single Blast Velocity Gauge,” presented before the American Foundrymen’s Association, Buffalo, N. Y., September 26. +American Brake Shoe & Foundry Company, Mahwah, N. J. tober 24, 1912 afety Device Practice and Accident Prevention he Engineering and Inspection Division of the Travel- Insurance Company and the Travelers Indemnity Com- y. Hartford, Conn., is preparing a new series of pam- ‘ts covering the subject of safety devices, approved .ctice and general accident prevention in different lines work and processes. The series is de- ned to cover the whole field of mechan- appliances and factory conditions, in far as they are inimical to the lives and sical welfare of employees. These nphlets are based upon an unequaled erience in liability work and upon a rough study in exhaustive detail of the t domestic and foreign practice in the ety of operation of plants and ma- inery. The first pamphlet in the series which eals with the subject of grinding wheels has just been issued. It discusses in con- iderable detail the speed, equipment and method of operation of this class of equip- ent. In addition to the text there are bles giving the speed measured in revo- THE IRON AGE got Planing Machine With Reversing Motor The Woodward & Powe!l Planer Company, Worcester, Mass., has designed a plani