The Iron Age 1920-04-29: Vol 105 Iss 18

New York, a VOL. 105: No. 18 Motor Car Assembling at Hudson Plant Parts Enter Separate Building Through Doors at Convenient Points and Are Assembled, Painted and Dried on Nine ROGRESSIVE assembly of motor cars with some form of conveyer equipment for moving the car as it is being put together starting with the frame, is standard practice with practical- ly all automobile companies that operate on a pro- duction basis, but the arrangement and equipment of assembly departments are being improved with equipment of new departments for assembling with a view to reducing costs, increasing speed and con- serving floor space. A late addition to final assembly plants in the automobile field, having new features, is one recent- ly built by the Hudson Motor Co., Detroit, to pro- vide for the rapid assembling of Essex cars. Parallel Conveyor Lines The assembling is done in a one-story building, erected for that department and is entirely separate from the manufacturing departments. This build- ing is 400 ft. long and 300 ft. wide of steel, brick and glass construction, with a saw tooth roof and concrete floor. Frames, motors, bodies and other parts are taken into the building through doors on whatever side is convenient to the point where they are wanted for the assembly lines. There are three duplicate conveyor lines side by side for assembling, painting and drying, and all the operations require three sets of lines, making nine parallel lines on one side of the assembly building. The first line is used for chassis assembling and for the first or A Corner of the Assembly Building from Which the Assembling of the Chassis Is Started. Rear axles and frames handled with hoists are placed on the racks that are located directly in front of the three lines of conveyors used for the first assembling operations lla ie 2 EEE EE ee a 1220 priming coat of paint. The first set of conveyors are 360 ft. long, 205 ft. being used for assembly and painting, the conveyor passing over the remain- ing distance through an oven for drying the paint. The trames and rear are taken into the building near the front the conveyors and are placed on racks in front of the conveyors, be- ing handled by Yale hoists before reaching the con- veyor lines. This conveyor consists of two endless chains moving just above the floor. Between the four-wheel steel truck 30 in. high is car front wheels of the truck being attached and the truck running in a track axles end of chain, a ried, the to the conveyo) that extends inside of the conveyor chain. On reach- ing the end of the line, the truck with the conveyor through a tunnel under the floor and back to the starting point. The automobile frame rests lengthwise on the truck during the operations, its The trucks are and the lines fa) to permit to work on all Part down the line, an frame and turns it over. Just 'e-ton Shephard electric hoist brings the motors from one side to the conveyor. With the assembled, the first paint is applied by spraying on the frame. is thrown from the frame by a suction fan, carried to a spraying pit and dis- After spraying, the chassis passes into an asbestos lined oven which is heated to a temperature of 170 to 180 deg. Re- cording thermometers are connected to the ovens. It takes 45 min. for the chassis to pass throug’ the oven and during that time the paint is dried. At the end of the first line of conveyors the chassis pass upon an unloading frame truck from which they picked up by Shephard electric traveling cranes, of special design to meet con- ditions required by the low head room. The roof passes first position being upside down. sufficient apart spaced at distance enough assemblers sides OL tne cCnassis. way air hoist picks up the beyond this point a chassis completely coat ol The excess spray of paint charged outside of the building. are — fl ef) eg x. ht er a oes a) THE IRON AGE April 29, ui) truss is but 14 ft. high, and the crane runway, above the floor and there is a space of onl) from the truss to the crane hook. This crane has a 35-ft. span and runs across the end building transverse to the conveyor, carri chassis to the next three rows of conveyor ft. long, which are located on a platform 8 ft the floor and supported by a steel frame con tion. Space under this conveyor balcony as a stock room for parts, metal racks bein; vided for small parts. On being placed on the second line of conv: the chassis moves back in the opposite dire from which it was conveyed on the first line. conveyor consists of two chains that slide on channels. On this conveyor the chassis is its second spray coat of paint after which it | into a second oven about one half the length « conveyor, taking 1% hr. to pass through this After leaving the oven, the chassis is cooled | forced over it and through ducts beneath. Aft the cooling, the wheels are assembled to the sis and the latter is picked up by a 1-ton and started back in the opposite direction on final assembly line, the wheels resting on a conveyor. Between the second and third conveyors a wheel painting balcony is provided wheels being placed opposite the point at wi they go on the cars and being delivered by gravit rollers. Running at right angles to the other lines of conveyors, are two body assembling conveyors. Bodies are placed on these conveyors by an air hoist, being set on trucks attached to the conveyo! chain. This truck after the body is removed, re turns to the opposite end of the line through a tunnel underneath the floor as in the chassis as- sembly conveyor. While the body is moving along this conveyor, the parts are assembled to the body and when the latter reaches the end of the line, it sf . led ad D .. -pemrneeeeeieeel _ a , - = 7 Nes * eee er bapengpal a paar ebas The Two Sets of onveyors are of parts located on Conveyors on Which the Chassis Is Given Its Second Coat of Paint and on Which the Wheels Are Assem- a platform above the assembling room floor providing space beneath for the This shows the crane that carries the chasses from the first lines of conveyors storage ri] 29, 1920 THE a end of the Conveyor, The picked up tric travel- I special iuse of the room, and the Tie xt line which back in th h \ \ l a point opposite the middle of final assembly conveyor. The is raised from this conveyor th a 1l-ton hoist which places it on the chassis the opposite conveyor. After the body is con- ted to the chassis, the car leaves the assembly e and moves to the filling dock and after being ipplied with gas and oil, is ready to run under own power. The speed of the conveyors is 33 in. per min. ind 6% hr. after the frame is placed on the chas- sis assembly line, the completed car rolls off the final assembly line. Welding Processes Discussed f I I The principles of arc, gas and thermit welding were presented at a session of the Metropolitan Section of the American Society of Mechanical Engineers, held in conjunction with the American Welding Society and the our metropolitan student branches of the society in the ingineering Societies Building, New York, April 13. ‘rof. Comfort Adams, president of the American Welding Society, in introducing the speakers, explained at the fields covered by the three welding processes be discussed were becoming more clearly defined and e boundary lines more closely drawn as the art pro- ressed, and that there were applications best served each of the processes now clearly recognized. The relation in are welding of the size of electrode, naterial of electrode, length of arc, method of holding the parts in position, and welding technique were ex- plained by O. A. Kenyon, engineer, Ray D. Lillibridge, ine. New York. The applications and the proper nethods of making single line, double line and rivet velds were pointed out. Most of the troubles encoun- ered in are welding, Mr. Kenyon said, were due to non- iniformity in the mechanical structure of the electrodes; flaws of various natures such as cracks, pipes, en- trained gas, etc., being the primary causes of trouble. here probably has been more advancement in the art the last two years, he said, than in the previous ten lhe history of the developments of gas welding and iracteristics peculiar to the ox-acetylene weld were ‘ussed by A. S. Kinsey, supervising instructor of shop practice, Stevens Institute of Technology, Hoboken. Welds of 100 per cent strength, he said, can be made y using a welding rod of greater strength than that ' the material being welded. The adaptability of the Process to welding the non-ferrous as well as the ferrous LRON 1221 AGE metals was pointed out. Portability, Mr. Kinsey said, had been a large factor in promoting the popularity of gas welding. Views were shown on the screen of welds made of low carbon steel in x of a locomotive, cast-iron weld in the side frame of a car, pipe, welding, ete. The process of thermit welding and its applications were presented by J. H. Deppeler, chief engineer Metal & Thermit Corporation, New York. The details of con- struction and operation of the crucible in which the aluminum and iron oxide reaction takes place were explained in detail. The temperature attained, the speaker said, requires a crucible of very high refractory material. Lantern slides showed how the sections to be welded were cut out, the wax put in place, and arrange- ments of the crucibles; also steps in the welding of crank shafts, large metal shear, steel rails, pipe, cast- iron frames of large punches, etc Screw Machine vs. Turret Lathe The Warner & Swasey Co., Cleveland, announces a campaign for discontinuing the name “screw machine” when applied to the modern turret lathe. It is ex- plained that the name “screw machine” is no longer appropriate when applied to the modern turret lathe, which is now seldom used for the making of screws, as automatic screw machines of various types serve this purpose better when large quantities are involved. Ten years ago bar work was the main product handled on what was then known as a hand screw machine; but to-day there is more chucking work performed on the turret lathe than bar work. Furthermore, the modern turret lathe is designed and constructed to handle heavy castings and forgings and is provided with sufficient power for machining tough forgings and alloy steel parts. For use merely for making screws, the present power provided in turret lathes would be superfluous. The Warner & Swasey Co. is urging all users and manufacturers to aid in the campaign for dropping the old term “screw machine” when applied to turret lathes. —_—____,—_—_ The Youngstown Foundry & Maehine Co., W. J Wallis, president, is planning to commence work on a new roll foundry at Girard, Trumbull County, where it owns a 12-acre site along the Erie right-of-way. The Erie is completing a siding into the property and material for the roll foundry will start to arrive within the next month. The company operates two foundries in Youngstown, which will be abandoned when the new plant is completed. By combining both foundries into one works, the company expects to effect a substantial economy in overhead and operating expense. ee erp a ensmaesigins sina at ae ee ee 1222 Geared Head 60-In. or 72-In. Lathe A new type of all geared head lathe to swing 60 in. and 72 in. has been designed by the Betts Machine Co., Rochester, New York. The head stock is of the all geared inclosed type, and is driven through an expanding ring friction clutch which is operated from the apron, a position convenient to the operator. The same movement which disengages the clutch automatically applies the friction brake, thereby to stop the machine almost instantly. There are 12 spindle speeds in geometric progres- sion controlled by conveniently located levers at the front of the head stock. All speeds are through in- ternal face plate gear and pinion. All speed changes are obtained through hardened steel sliding gears and positive clutches running in oil and having edges of gear teeth rounded to allow for speed and ease in engagement. No two speeds can be engaged at the same time. All shafts and gears are located in the lower half or base of the head stock and are thus made readily accessible when the cover is re- moved. All shaft bearings are bronze bushed and all bearings are lubricated by chain oilers. When motor driven, the motor is mounted on top of the head stock cover and direct connected through gearing to the main driving shaft. There are 32 changes of feeds and leads obtainable through quadrant gearing and quick change gear box to lead screw. Feeds are driven from a spline in the lead screw to the rack on the bed through all gearing and large frictions. No two feeds can be engaged at the same time. Feeds and leads are inter- locking, so that only one can be in use at one time. The apron is of the double wall unit casting con- struction, there being no overhanging studs. Al! shafts have a bearing on each side with gearing running in oil. The power angular feed to the compound is driven from cross feed friction, a slip gear being provided for cross feeding or power angular feed, and are re- versed at the apron. Both feeds and leads may also be reversed at the head stock. Power rapid traverse is obtained by a friction clutch on the lower shaft in a quick change box which is driven from the constant speed head stock driving shaft by Morse silent chain at the head end of the lathe. Rapid traverse is operated by a lever at the apron. The movement which engages the rapid traverse clutch automatically first disengages the feed and lead making it impossible to have beth engaged at the same time. The rapid traverse is ap- plicable to longitudinal cross or power angular feed. steel The firm of Hogan & Donnelly, Philadelphia, iron and steel, bolts and nuts, supplies and equipment, has been dissolved as of April 1. The business will be hereafter conducted by Michael Donnelly, trading under the name of Donnelly & Co. THE IRON AGE April 29, Al Senate Will Investigate Housing Con- ditions WASHINGTON, April 20.—The Senate has adopted a resolution offered by Senator Calder, of New providing for an investigation of the housing tion. It is proposed that a committee of five Se shall be authorized to conduct an inquiry ext; over a wide scope. The committee is authoriz inquire into the existing situation in relation ¢ general construction of houses, manufacturing « lishments, and buildings, and the effect thereof other industries and upon the public welfare, a: recommend such measures as may be deemed neces to stimulate and encourage such construction wo) encourage popular investment rather than spending, : foster private initiative in building, and to insw operation between labor and persons or corpora engaged in transportation, banking and other bu necessary to the development of such constru The committee, which is to be appointed by the New Type Betts-Bridgeford All-Geared Head 60-i Lathe. There are 12 spindle speeds and 32 changes and leads dent of the Senate, is to consist of three Republicans and two Democrats. It is instructed to report to the Senate on or before Dec. 1. In stating his purpose in presenting the resolution Senator Calder said that there is to-day a shortage of building material of every character, a shortage of rail- road facilities to transport building material, a short- age of fuel necessary for the manufacture of building material, and a great need of additional labor for the construction of buildings. Senator Calder, who him- self has had many years’ experience in the construc- tion business, said that although some building invest ments are attractive, there is a great shortage of money to finance building operations. He said that men of great wealth who formerly invested some part of their means in mortgages on real estate are rapidly calling in these mortgages, the reason being that the high income and excess-profits taxes on large incomes have reduced the net income on these investments to the neighborhod of 2 per cent, so that much money that formerly went into mortgages is now being vested in State and county bonds, which are exempt from all Federal taxes. Senator Calder said his personal experience showed that its costs 75 per cent more to build a house than last year, and 150 per cent more than in pre-war times. Electrical equipment in industrial plants is the su ject of No. 29 of a series of bulletins entitled Sate Practices, published by the National Safety Council, 168 North Michigan Avenue, Chicago. The pamphlet discusses dangers of shock, burns, flashed eyes ana mechanical injuries from electrical utilization equ'p- ment carrying less than 750 volts, and located so that it is accessible to other than qualified electrical opera- tors. Evolution of the Electric Brass Furnace Electric Crucibles—Overhead Resistor and Induc- tion Principles—Are Type Units Using Mechani- cal Agitation—Advantages of Electric Melting BY H. M. rule, on the difference of method utilized for the application of heat to the material under itment. In this case the species are three: ‘ N electric furnace classification is based, as a a. f e induction or direct resistance furnace, in which heat rated in the metal itself by virtue of its own re » the passage of an electric current. ire turnace, in which heat is generated between an and the metal, or between independent electrodes sferred to the metal by conduction or radiation or indirect. ndirect resistance furnace, in which heat is trans from an incandescent resistor to the metal by con or radiation, somewhat as in the are furnace \ll of the electric furnaces so far proposed for ting brass naturally fall in one of these classes, combination of some two of them Electric Crucible Furnaces. In the beginning the would-be inventor of an elec- brass-meiting furnace was obsessed by the idea hat such a furnace should bear a close resemblance to the combustion furnaces then in use for that pur- pose. In the electric crucible furnace, as in the fuel- fired crucible furnace, the heat must, in general, be generated at some point outside the crucible and trans- nitted to the metal through its walls. A favorite sug- gestion was to surround the crucible with an electric sistor of granular nature, which was heated to In- indescence by the passage through it of a suitable electric current. Most of these fundamental difficulties were ob- iated by using a resistor which surrounded the cru- ‘le but did not come in contact with it. In this way heat generated in the resistor was first transmit- ed to the crucible by radiation, and, finally, by con- luction through the walls of the crucible to the metal. To the writer’s knowledge, the only furnace of this type which was ever operated with any degree of technical success was equipped with wall resistors of thin carbon slabs, provided with means of variably ad- isting the contact pressure between the slabs. The generation of heat in this furnace depended, not on the resistance of the carbon itself, but on the contact re- sistance between the slabs, which could be varied at | in such a way as to provide an excellent means controlling the current and voltage, and thus the rate of power input. Despite its good qualities, it soon apparent that this furnace could never be mmercially successful. Its maintenance cost, both ‘carbon electrical parts and refractories, was a seri- is handicap, but more serious still was the fact that thermal efficiency was inherently and irremediably “ The latest proposal to melt brass in an electric rucible is one which has recently been very thor- ‘hly described and discussed, in which the metal thin the crucible is heated by a high-tension, high- juency induction or eddy current. The walls of crucible itself are electrically conducting and serve heat its contents during the period while the metal ll solid and in pieces not in good electrical contact each other. Most of the disadvantages already ribed as characteristic of the crucible furnace have overcome in this design. This new type has, vever, so far been built in sizes more suitable for _laboratory than the foundry. lhe low thermal efficiency of crucible furnaces "From a paper presented at the annual spring meeting © American Electrochemical Society at Boston, April he author is sales engineer, Detroit Electric Furnace Detroit. ST. JOHN heated from without naturally suggested the possibil- ity of utilizing the walls of the crucible itself as a re- sistor. This principle was tried out quite thoroughly rather early in the development of electric furnaces for melting brass. In one type the crucible was built of a special mixture with suitable electrical conductivity but no attempt was made to insulate the walls of the crucible from the metal which it contained. In another design this feature was taken care of by means of a special insulating lining separating the conducting walls from the metal. It proved almost impossible, however, to maintain this insulating layer, and short circuits invariably resulted. Overhead Resistor Furnaces. Not all, even of the early experimenters, limited their attention to the crucible furnace. The advantages of a larger furnace capacity and the elimination of crucibles were sufficiently obvious, and had already re sulted in a considerable use of various types of direct flame oil and gas furnaces. The earliest attempts to melt brass electrically in a furnace of this sort made use of an incandescent resistor supported above the bath and radiating heat directly to the metal. This construction, applied to an open-hearth furnace of small capacity, gave rapid melting and a fairly high thermal efficiency. The principal difficulties were two: the development of a resistor which would stand up continuously under the required conditions without an excessive maintenance cost, and the invention of some reliable method for supporting the resistor in the de sired position over the bath. Neither of these basic problems has ever been adequately solved. The difficulties which interfere with the use of an overhead resistor are partially avoided if the resistor is located above the bath, but at either side or sur rounding the central portion of the melting chamber One well-known type of furnace now in commercial use employs this principle, utilizing for the purpose a granular resistor contained in a nearly circular re fractory trough. This trough is exposed to very severe usage since the resistor temperature must be much above that of the molten metal. The roof also is at a temperature considerably in excess of that of the metal and must be highly refractory. Another type of furnace which is in somewhat limited commercial use employs a combination of granular resistor and smothered arcs at either end of the melting chamber. In this type also most of the heat must first be radi- ated to the roof and then to the metal. The Induction Principle. A high thermal efficiency was early recognized by several of the more far-seeing investigators in this field as an absolutely essential qualification for the permanently successful electric brass melting furnace. It seemed obvious that if some practical method could be devised for generating heat in the metal itself, con- ditions most favorable for a high efficiency would be produced. The celebrated pinch-effect phenomenon is too well known and has been too often discussed to re- quire definition here. The pinch-effect can be utilized to increase substantially the electrical resistance of molten brass through which a heavy electric current is flowing. This was done with considerable success in designing the first practical direct-resistance furnace for brass. It has recently been proposed to change the construction of this furnace in such a way as to elimi- nate the massive metallic electrodes. The elimination of electrodes from the design of the direct-resistance furnace was evidently of the high- 1223 et TC A A GS RC RE ee my austumpwaan Spoaunaranigumnainanennanintuparemaas are oe ee aes at o - : es : é ' 1224 est importance. This was done in a somewhat later type of furnace by constructing it as a vertical-ring induction furnace with the resistor channels joined at the bottom to form a complete circuit for the passage of electric current. The limitations of the vertical- ring induction furnace are due, first of all, to the fact that it is an induction furnace and, as such, cannot be constructed in large sizes without introducing elec- trical disadvantages such as low power factor. Furnaces of the Arc Type. The widespread success of are furnaces in the melting of steel was not overlooked by those more particularly interested in the brass industry. Many attempts were made to apply both direct and indirect are furnaces directly to the melting of brass, without changing the design which had been found most suit- able for steel melting. These attempts were pretty uniformly unsuccessful, because copper and its alloys —particularly the high-zine alloys—suffered under the direct application of such a high temperature heat source as the electric arc. A great deal of study was devoted to the discovery of some method which would make possible the utiliza- tion of the good features of the electric are for brass melting. The direct type of arc furnace was evidently out of the question. In the indirect are furnace, over- heating was less localized. It seemed probable that if the metal could be stirred with sufficient vigor, the entire bath could be maintained at a uniform temper- ature, and tendency toward local overheating could be entirely neutralized. It was found by experiment that rocking the furnace mechanically, at the rate of ap- proximately two oscillations per minute, resulted in a degree of agitation ample to maintain complete uni- formity of temperature throughout the molten bath, and that the obvious advantages of the are furnace could be utilized in this way without the slightest in- jury to the metal, even in the case of alloys contain- ing 40 per cent or more of zinc. The so-called rocking electric furnace resulted from this development and is in wide commercial use at the present time for melting all classes of copper alloys, as well as copper itself. As in the induction furnace, the vigorous stirring of the metal results in a uniformity of temperature and of composition throughout the alloy, a feature which is of particular importance in the melting of high-lead alloys. The pronounced success of the rocking type of arc furnace has prompted many suggestions for modified designs, similar to it in principle but differing from it in details of construction. For example, it has been proposed to rotate the furnace body instead of merely oscillating it. The evolution of the electric brass furnace has now proceeded to such a point that fundamental improve- ments in design are henceforth likely to be rather slow to materialize. There will, of course, be constant progress in the development of refinements in mechan- ical and electrical design, calculated to make the fur- naces more reliable, more durable, and more nearly fool-proof than they are at present. Advantages of Electric Melting This brings us to a brief consideration of what the foundryman can expect and ought to realize from the use of electric furnaces. The first and probably the most important point is the saving of metal—commonly wasted during the melting process—which electric melting makes pos- sible. If the charge to be melted consists of new metal or clean scrap, the net metallic loss during melting and pouring from the furnace should not exceed one per cent for yellow brass and 0.5 per cent with red brass. With clean yellow brass, containing 40 per cent of zinc, losses as low as 0.75 to 0.85 per cent have been experienced as an average for a considerable tonnage of metal melted. In melting a scrap charge containing brass a high percentage of non-metallic, such as oily bor- ings, chips, grindings, etc., the net loss should not exceed two per cent. It is also true that the furnace which melts with- out agitation is not particularly well suited for melt- THE IRON AGE April 29, 1529 ing a charge which contains a high percentage o ly divided, dirty scrap, while these can be ha i without difficulty in either induction or rocki) furnaces. Brass melted in the electric furna practically free from metallic-oxide drosses a: no opportunity to pick up sulphur or other conta tion from combustion gases. The consumption of electric energy under avers, conditions of 8 to 10-hr. operation is as low as 240 kw. hr. per net ton for yellow brass, and 275 kw per ton for red brass, in the induction or are furne In 24-hr. operation figures as low as 200 kw. h: ton or less, have been obtained. Less efficient fy nace types use from 400 to 500 kw. hr. per ton, pending upon conditions. Flexibility, which in this case may be defined as the suitability of a furnace for radical changes in op: ing conditions or for an abrupt change in the com- position of the alloy to be melted, is a marked charac- teristic of the resistance and rocking arc furnaces. which is notably lacking in the induction furnace. The net melting cost, considering all factors whic! should properly be considered under this head, is natur ally lower in those furnace types which melt the meta! most rapidly and efficiently, since their use of electri energy is more economical and their higher rate of production reduces the fixed charges per ton of metal melted. In many cases, the cost of electric melting is not more than half the cost of melting the same alloy in combustion furnaces. Even in the less efficient fur- nace types, electric melting is usually less costly than the older methods. Electric brass melting can no longer properly be called “the coming thing.” It has arrived in a most convincing fashion, as is evidenced by its rapid adop- tion by the larger and more progressive rolling mills, foundries, and manufacturing establishments which use brass in large quantities. The Carelessness Factor WASHINGTON, April 20.—The Bureau of Labor Sta- tistics has issued a revised bulletin on accidents and accident prevention in machine building. This takes the place of the previous bulletin issued in 1917. The latter contained statistics covering the period to 1913, while the new issue uses figures covering 1917 and a part of 1918. It also includes an interesting chapter on the influ- ence of the war on accident rates in machine building. This is based on the. statistics obtained from 100 estab- lishments of the 194 which contributed statistics to the previous bulletin. The remaining 94 firms declined to submit the desired information, says the bulletin, on the ground of excessive pressure on their clerical forces. The figures reveal a general increase in the seriousness of accidents but a decline in their frequency. In the manufacture of machine tools, both frequency and severity increased—the frequency practically doubling and severity trebling. In the manufacture of electrical apparatus the frequency declined 65 per cent and the severity rate 21 per cent. Navy yards considered as a unit made a marked improvement in both frequency and severity, says the report. The accidents in private shipyards declined in frequency but increased in se- verity. The bulletin contains an interesting comment on “human carelessness”: “Evidence is not wanting in the material considered in this brief review,” says the bulletin, “that some of the engineers who share in the credit for this ex- cellent showing are still too much impressed by the human factor and attribute too much to so-called ‘care- lessness.’ “Not until this idea is cast out of the mind of the men directly in charge will the engineers get down t the real fundamentals of accident prevention, namely, (1) adequate ‘engineering revision’ and (2) proper supervision of men and instruction in safe methods of doing work.” The bulletin just issued, “No. 256,” is liberally illus- trated. Copies may be procured from Superintendent of Documents, Government Printing Office, Washington. Design of Open-Hearth Furnaces Calculating the Size of the i Regenerators for a 50-ton | Furnace Using Producer Gas | BY A. D. WILLIAMS ) rN AKING up the design computations for a 50-ton Total coal consumption 200 “ 50 15,000 kg. ypen-hearth furnace regenerator, the following (for the 500 min.) The average coal consumption will i} assumptions are made: be 30 kg. per minute, or 0.5 kg. per second. The max- capacity of furnace..............6: ......50tons imum rate of coal consumption will be approximately i ; of Beats Be WOE WORE, 660.060 se casecancedene 15 on L — Tite ane rasifie : a vr -er i time per heat, charge to tap..........8 hr. 20 min. 1.25 kg. per second. This coal gasified in a produc : l} sumption per ton of steel....... .. .300 kg. (660 Ib.) supplies 3.5 cu. m. of gas per kilogram of cval gasified tou number of reversals per hour F 3 : : air supply, per cat an theoretical y 140 and this gas, burned with 40 per cent excess alr, re- —- * “ 7 x VA OI ——— — — Gas Y 7 nik aera emia ae , _ Waste Gas z »~< a€ Ca rek + ‘ A A ~~ , s sea ais |. Kee g Af 4 ‘ 1 |O- ian A | VAZ v~ a A + ‘ =" eee a - a / - > <0 ~ rx y =< Biya 4 t f ee "2 Gc . ¢ <7. o- S24 7 1 ces ace 2) Ba — ' { n.jof , Gases of Combustion o7 Bu y 1 fH Produce Gas Calories () ) Het) N H. 11.26 x 58.2 655 11.26 oc.ne Capacity Curves CH, 3.24 X 195.2 632 6.48 a4 6.4% 69.96 CO 29.65 X 68.2 » 02 1.83 +f 9.32 Gas, Various O2 0.19 : . COs 25 1.2 Supplies and Their —* ot 69 Combustion H2O 3.7 (a Curves Ir 100.00 509 26.94 4.14 21.46 158.45 — . f ; 0.76 Calorifie In- is \ffected by 26.75 34.14 21.46 157.69 legrees of Pre- Combustion of 100 Molecular Volwmes of (as +} . Air Products of Combustion in Molecular Volumes _ Air, the Supply Molecular Excess Excess s Both the Air Per Cent Volumes Air Os CO2 H2O Ne Ne Total ; 100 133.75 0.00 0.00 34.14 21.46 0.00 157.69 213.29 t the Gas. 120 160.50 26.75 5.35 34.14 21.46 21.40 179.09 240.09 140 187.25 53.50 10.70 34.14 21.46 42.80 200.49 266.79 180 240.75 107.00 21.40 34.14 21.46 85.60 243.29 320.29 These volumes may be evaluated as cubic feet, cubic meters, et a \ portion of this air is required for the oxidization quires 1.87 volumes of air per one volume of gas and i, ertain elements in the charge and additions. the products of combustion will be 2.68 volumes. Fig. i i 20 shows the heat capacity and calorific intensity “Copyrighted 1920 by A. D. Williams. In this series ‘ . il appeared the following: Jan. 1, empirical nature of CUrves of the producer gas, the air supply and the ite th proportions; Jan. 8, flow of gases within the fur- waste gases, as computed according to the methods of iy ®. Jan. 29, port and roof design; Feb. 12 and March 18, : i 1 generators Mallard and Le Chatelier. These curves are based uae 1225 t 1226 upon the combustion or burning of 100 molecular vol- umes or of the gas fuel under considera- tion for use in the furnaces. 2.232 cu. m. Required Available from for Products of Heating Combustion Gas Air Gas Air Checker Checker Checker Checker Temp. top of checkerwork, deg.1200 1200 1700 1700 Temp. bottom of checker, deg 600 200 800 600 Temp. increase or decrease, deg. 60 900 900 1100 Heat capacity in calories at . ce hae 1700 deg 4140 4140 (Based upon 100 1200 960 1700 molecular volumes 800 1750 : of the gas burnt 600 450 , 1250 from curve of Fig 300 aa 480 20.) Heat in calories per 100 molec- ilar volumes of gas burnt to be given or ibsorbed from checkerwork . ; ka wa ee 1220 2390* 2890* Heat in calories per cubic meter of gas burnt to be given out by o1 absorbed by checker work 228 546.6 1071* 1295° By assuming that 2 cu. m. of gas are burned the he heating of proportion of the products of combustion required for t the two checkers may be arrived at: Heat Available from Heat Products of Required Combustion for Gas Air Gas Air Checker Checket I ga ees 2 157 b'< 546. 2 2 \ ble products of cor pustion . 7 l , I l qui 1 and available -s6f Per 4 t ( ta I quired. ? Uv ~- He { i b req red for tt ras cr 1 2366 29.48 64 H t V ble quire 1 for tt T ctr ker 23 6¢ 70 2 GES Volun f products of ymbus on required for gas checker 697 1071, p nt 65.1 Volume of products of combus t required for air checker 1668.5 1295, per cent : 128.86 Total per cent waste gases 19 9 Correction to make 00 pel Ce nt 6 01 Corrected per cent values.... 67.00 133.00 Reducing these to a 100 per cent basis 3 50 66.50 { Lor I I cul rn gas burned s 16.6 9 861 Volumes é cul g burned ( 87 0.97 1.78 The surplus heat over that required for the pre- heating of the gas and air will be: For the gas checke! og 228 130 calories For the air checker S61 46.6 314.4 calories This surplus supplies the heat lost by radiation conduction and convection from the checker or regen- erator chamber and should these losses ve not suffi- cient to absorb this amount of heat the final tempera- ture of the products of combustion leaving the check- ers will automatically increase until the heat carried back into the furnace by the air and gas plus these losses equals the amount of heat given to the checker- work by the products of combustion. The maximum quantity of gas required will be: 3.5 (cu. m. per kg.) & 1.25 (kg. coal) 4.375 cu. m. per The maximum quantity of air required will be: 4.375 1.87 8.182 cu. m. per sec. The maximum volume of the products of combus- tion will be: 1.375 per These volumes are reduced to zero Centigrade and 760 mm. of barometric sec. < 2.68 11.725 cu. m. sec. pressure. *Note: These values give the total amount of heat available in the products of combustion of 100 molecular volumes or one cubic meter of the gas cooled through the assumed temperature range of either the gas or the air checker, and which must be divided between the two checkers. 0.335 and 2.68 xX 0.665. #2.68 volumes THE IRON AGE April 29, 1929 The average volumes will be as follows: of gas: 3.5 0.5 (kg. of coal) 1.75 cu. m. pi of air: 1.75 & 1.87 = 3.273 cu. m. per sec. of products of combustion: 1.75 * 2.68 4.69 per sec. r——Reversal Pe 20 min 1200 sec. 1® Gas: Max. calories 4.375 X 228.5 x ¢ 1 200 000 1 Air: Max. calories 4.375 < 546.6 x ¢ = 2 871 000 4 Gas: Av. calories Le x< Bee MY : 480 000 Air Av. calories 1.75 x< 546.6 x ¢ : 2 346 O6@ 1 7: Allowing for a range of 200 deg. in the ch brick and 90 per cent of its weight as effective, weight of brick required will be: For gas 20 min. : 1,200,000 (200 0.25 X 0.90) 26 667 kg 30 min 1,800,000 (200 * 0.25 & 0.90) ates 40 ke For air: 20 min 2.871.000 (200 « 0.25 0.90) 63 800 kg 30 min 4,306,000 (Zee © U.aed Mm Ceer «ees 95 68 The brick will weigh about 1800 kg. per cu. n therefore the volume occupied will be: For gas: 20 min. period, 26.667 1800, cu. m 14.32 30 min. period, 40,000 1800, cu. m oka 22.2 For air: 20 min. period, 63,800 1800, cu. m. 35.45 30 min. period, 95,680 1800, cu. m aes 53.137 Increase in temp. in checkerwork, deg Gas Air Gas: 1200 - 600 600 Air: 1200 300 ae 90I Average temp. in checkerwork, deg. Gas: (1200 600) 2 900 Air (1200 300) 2 ent 750 Average time in checkerwork, se¢ At 100 deg. increase in temp. per sec 6 “ At 200 deg. increase in temp. per sec 3 4.5 Gas: Aver. volume per sec, at 900 deg., cu. ft L.78 xX Ch + 28) 7.53 Air: Aver. volume per sec, at 750 deg., m 3.273 X (1 at) ee 12.28 With 200 deg per sec. increase in temp, the volume required for the passes will be, cu m Gas 7.53 x $3 22.59 Air: 12.28 4.5 With a temperature rise of 100 deg. per sec. the volume required for the passes will be double the above Fig. 18, (page 806, THE IRON AGE, March 18) shows that with the usual period between reversals, there will be no economy in increasing the thickness of the checker brick over 2.5 in. (63 mm.), which is a standard shape. The volume occupied by the checker brickwork wi be the sum of the brick volume added to the pass vo! ume and requires no explanation. With a different producer gas and a different air proportion there would corresponding change in the amount of heat interchange required and in the volumes required fo the brickwork and for the passes. The height of the checkerwork should be made as great as possible, say 5 (16.4 ft.) as a minimum. Th« flues below the checker should be proportioned to per mit free flow to the passes at a low velocity. If de sired, the height of these flues may be stepped down, proporticnally to the distance from the inlet. This, however, introduces complications in the brickwork with comparatively little gain. The vertical velocity of the gases checkerwork may be considerable and it is necessary to provide sufficient space above the checker to get rid of the eddies which will be formed. Unless sufficient space is provided these eddies will cause considerabl interference with the flow of the gas from the checker chamber into the slag pocket, converting what should be a smooth regular flow into a series of bursts 0! blow-throughs. These bursts may have entirely differ ent periods in the air and gas chambers and result in considerable irregularity of combustion and waste of fuel. be a leaving the (To be continued) \pril 29, 1920 GERMAN WAR COPPER SUPPLY Inside History of Methods Adopted to Get Copper and to Provide Substitutes Valuable and interesting information regarding Ger- iny’s copper consumption and supplies during the war nd the means of economizing and recovering the metal s contained in an article in Technik und Wirtschaft, is contributed by Herr Schulz. An abstract appeared an issue‘ of Technical Review, London, which was in part as follows: Annual Needs The annual German requirements of copper for military and naval purposes being about 120,000 tons, whereas the production from the home mines was only ittle over 23,000 tons in pre-war days (declining to half that amount in a short time, owing to the mobili- ition of the miners), it soon became necessary, after he blockade, to requisition some portion of the million tons of copper existing as utensils and other manufac- ired articles. The first levy on domestic utensils yielded 40,000 tons, and considerable quantities were »btained from bells, roofing sheets, guttering, copper tills, ete., together with the spent ammunition sys- tematically collected by the army authorities after the war of position had set in. During the first two years of the war the deficit was partially covered by booty from Belgium, France ind Russia. Large quantities of scrap copper and brass were collected from munitions works and from fittings on naval and mercantile vessels, the scrap being smelted and refined, and then converted into electrolytic copper. Cupriferous slags were treated by the Dwight Lloyd process, the roasted product, with 30 to 80 per cent of copper, being refined to 89 to 90 per cent and cast into cathodes. Brass scrap was smelted in basic Bessemer con verters in which, by using a compressed air blast, the refining process was shortened from several days to a few hours. The zine fumes were cooled in a system of tubes to 50 deg. C., and collected in bag filters, the ‘ontents of which were compressed into blocks and con- verted into pure zine by the electrothermic process. Copper and Tin from Bronze Bronze scrap, with about 90 per cent of copper and 10 per cent of zinc was successfully treated by elec- trolysis, the melted metal being formed into cathodes which were electrolyzed in copper sulphate, several weeks being required for the deposition of the copper The dried sludge from the process contained up to 60 per cent of tin, which was recovered as pure metal. 3y instituting a system of checks on waste in re- covery, it was found that the losses in remelting brass were only 2 to 2% per cent, and in casting and machin- ing, 6 to 8 per cent. With condenser tubes (70 Cu., 29 Zn., 1 Sn.), 3 per cent of copper and 7 per cent of zinc; with turbine vanes (72 Cu., 28 Zn.), 2% per cent of copper and 3 per cent of zinc; and with copper tubes, 2 per cent of metal, most of which (1.3 per cent) was recovered from the sludge. In order to increase the output the Mansfield mine worked ore as low as 0.8 per cent of copper, and thus succeeded in producing 2400 tons of metal per month; and the Bor copper mine, captured in Serbia, was made to yield about 14,000 tons per annum; while a few hundred tons were obtained from the Plakalnitza mine in Bulgaria. Substitutes for Brass To minimize the consumption for army purposes, all brass and copper uniform badges, etc., were ‘abol- ished, zinc replaced brass in munitions, and zinc, aluminum or iron was used for conducting wires. In spite, however, of all these economies, the consumption remained enormous, and by the end of 1916 stocks had become exhausted. This necessitated the substi- + ution of iron in cartridge cases, caps, and driving bands, all tubes and wires in electrical plant, torpedo THE IRON AGE 1227 tubes and propellers on small war vessels. For medium shells, zine driving bands were used, and electrolytic iron for those of large calibre. In the navy cast brass (55 to 60 per cent Cu) re- placed admiralty bronze, the tendency of the former alloy to pipe and froth in casting hollow articles being counteracted by making the gate of equal capacity with the mold and allowing time for the included oxides to rise to the surface before actually running the metal into the mold. The risers were also plugged, and the imprisoned air only released when the mold was nearly full. These alloys failed to stand friction, and therefore parts exposed to heavy wear had still to be made of the old alloys. An iron bronze, produced by Goldschmidt of Essen, containing 57.7 Cu, 40 per cent Zn, 1.8 per cent Fe, and 0.4 per cent Pb, could be forged between red heat and dark red heat, and gave clean, compact cast- mgs. Other Novel Substitutes For ship propellers, attempts to protect steel from eorrosion by coating with Cellon varnish or enamel proved unsatisfactory, but better results were obtained by coating with lead, this method being also applied to submarine parts in contact with sea-water; but the speed of torpedo boats with these propellers fell off by % knot in two to three months through corrosion Zine replaced copper in protecting ships’ compasses against the disturbing effect of adjacent iron, and zinc-aluminum alloys were found suitable for conduct- ing wires, etc. Copper tubes were first replaced by brass, and afterwards by steel coated with lead, and condenser tubes by pressed brass (62 per cent Cu), which in some cases proved better than 98 per cent copper, the former not requiring to be tinned if hard- drawn. Iron acted satisfactorily for spacing pieces in steam turbines, but not for vanes, and nickel-plated or enameled steel also failed to answer for this purpose. More promising results are expected from nitrogenized iron, prepared by a process in which the heated vanes are exposed to a current of gaseous ammonia, the nitrogen cf which combines with the iron, while the hydrogen reduces any superficial oxide. Though aluminum can be used in land insta!lations for conducting wires and their connecting sleeves, smal] armature windings and collectors, if protected from abrasion or contact with copper or iron in damp air, it is too liable to corrosion by sea water to be used on submarines, the electrical plant of which was the chief consumer of copper in the navy; and copper had to be retained, especially for movable cables, which are subjected to rough handling. Aluminum was used in some cases to replace lead for wires of small sectional area (about 1.5 sq. mm.). Locomotive Building in Belgium WASHINGTON, April 27.—Although all the locomotive works in Belgium, except two, have resumed operations little has been done as yet toward the production of new engines, according to information forwarded by Vice Consul Carl C. Lumry, at Brussels. All Belgian build- ers are occupied at present in overhauling locomotives of the State Railway, including the light railway lines. A number of locomotives which were ordered in 1914, material for which was hidden and escaped the at- tention of the Germans, are now being completed, as are also a number of locomotives intended for the light railways and a small number for the use of Belgian industry. Present conditions of production are con- sidered very unfavorable on account of the cost and scarcity of al] raw materials, the reduction in the hours of work, the demands of the workers, and the exodus of many of the better workmen to France and England, where wages are said to be even higher. The Belgian Government has recently placed an order with Belgian builders for 100 locomotives; this in addition to the order placed in the United States for 150 locomotives. It is thought that it will be necessary to place another order with foreign builders for locomo- tives and railway equipment in the near future, as the Belgian works are not in position to take care of the Government’s needs pS ae RE KS 4s i ear pee mo 1228 UNITED STATES EXPORTS Comparison of Tonnages Sent Abroad During the Past Five Years WASHINGTON, April 27.—In an effort to shed addi- tional light on the extent of increased exports during the past few years, the Bureau of Foreign and Domestic Commerce has compiled a table showing quantities of 47 classes of principal domestic exports during the fiscal year ending June, 1914, the last year before the war, and each successive year up to the fiscal year ending June, 1919. These 47 classes embrace the 100 principal commodities of domestic exports for which quantities in weight or in units which can be readily reduced to weight are stated. The purpose of the inquiry is to get a more satisfactory basis of comparison in view of the confusion caused by the large increases in values of exports during the war period. Inasmuch as most of the export figures made public are in terms of value, the enormous jumps in totals have tended to give a somewhat erroneous impression. The compilation of the