The Iron Age 1923-04-12: Vol 111 Iss 15

LISHED 1855 rc IXTURES for use under radial drills permitting the easy handling of large castings have been developed for its manufacturing processes by the Geometric Tool Co., New Haven, Conn., manufacturer of threading devices. Some of the clamping or register- ing devices used may prove of interest to other manu- facturers who handle similar shapes or kinds of cast- inos ine in place in place Fixtures Used in Machine Tool Production Extensive Use of Screw Bushings—Drill Jigs for Holding Large Castings—Production Increased Three to Four Times Over Old Methods Threading Machine Carriages are Held Set Screw Through One screw bushing (upper left). of pump chamber pump body lever (lower Threading in a cradle swing on the cradle, which is held in position by 1021 serves to hold speed change A removable plate permits counterboring (upper right) (lower right) a pinion and gear segment tilts a locking pin . Renee Mae oy 3 is . “ne 7 * & eae 2 me mtn meme lag 2 .. 1022 Several uses of the screw bushing are shown. One operation is the drilling of holes in all sides of the threading machine carriage. The casting is first milled on the main ways and tee slide before proceeding to the drilling operation. In the drill jig it registers from the milled through a_ straddle leaf which With only a set screw casting is held. The second example of the use of the partly engages the tee surfaces, slide. and a screw bushing the securely bush- this screw ing is in the drilling of speed change levers. In the large hub end of the having been first faced on the of a bell mouthed screw bushing bearing on the turned handle end. A block holds the lever from side play. This block slips between the two small finished bosses in the parallel arms of the lever. case leve r, bosses is forced into a vee block by means guide Geared pump housings are drilled completely in one jig. First the bottom and wings of the casting are surfaces the hardened machined; from these casting is registered in the drill jig; it rests on pins and is THE IRON AGE April 12, When the casting is central horizontally, screw ings are adjusted to hold it in place vertically. are drilled from three sides. A large type of swivelling fixture is employ: holding threading machine columns for drilling fixture consists of a cradle with trunnions having ings in a base or frame. On one trunnion is with teeth cut around part of the periphery, n with a hand operated pinion. This permits th ing to be swung around to different angles f drilling of the required holes. A locking pin casting engages with holes in -the cradl holding it firmly in the desired position while d is performed. A toggle lever is used for clamp casting in the cradle. An interesting operation in gang milling ployed in this shop. In this job three carriag« jaw slides are clamped on the table of the ma Five flat surfaces and a half round groove are at one setting. The castings having first been fi) by milling on the main ways are registered fron base Six Surfaces Milled at (once clamped in place by a removable plate permits counterboring of ing of drive shaft Screw bushing. A ' the chamber and pinion stud holes. bushings are likewise used in the jig for drilling circular yoke levers. This fixture is made with vee jaws, one of which is adjusted with a thumb screw. screw and ream- Coke Market Softens—Protest Car Service Against Poor UNIONTOWN, PaA., Connellsville region week just closed, April 9.—The coke market in the softened considerably during the quotations ranging around $7, with some spot sales reported as low as $6.50. This situa- tion, it is believed, is brought about by the embargoes to Greenwich piers on the Pennsylvania Railroad and curtailment of export shipments. Coke production for the week ending March 381 hit a new high record for the year with 297,350 tons, an in- crease of 7140 tons, of which increase 6400 tons was merchant output. One hundred and sixty-two ovens were added to the active list. Merchant production, it is believed, has now been brought very closely to the current demand. The softening of prices in spot coke is believed tem- porary and a firmer market is expected when the em- bargoes are lifted. Some furnace coke was sold on the spot market during the week at $6.50, although the spot market generally is around $ Steam coal hovers around $2, with by-product coal ranging around $2.50. Car placements for commercial loading on the Baltimore & Ohio F. M. and P. branch in a Gang Set-up Greatly Increases Production of Chuck Jaw Slides finished portions with adjustable stops for lining uy the work. The use of fixtures above outlined has considerably reduced the cost on these operations, having increased production three to four times, and accuracy and inte! changeability have been maintained. are around 20 per cent; on the Pennsylvania around 10 per cent, and on the Monongahela Railroad around 1 per cent. Sharp protests have been lodged with th railroads over this condition and with the Pennsylva for its policy of providing an 80 per cent or better placement for coke loading, operators contending that considerable number of coal cars are being diverted ' coke loading. nit a ° ° ° 99 Lead Production and Consumption in 1922 The production of refined primary lead in the United States in 1922, according to C. E. Siebenthal and A. Stoll, of the U. S. Geological Survey, was 532,662 net tons. This compares with 448,589 tons in 1921 and with 529,657 tons in 1920. The apparent consump- tion of refined primary lead in 1922 is reported 4 492.705 tons; in 1921 and in 1920 this consumption was 444,872 tons and 538,020 tons respectively. Walter Moore, president of the Empire Coa! © Birmingham, Ala., says one bid to build a 50-ove! by- product plant for his company at Empire coal mines has been received and others are expected this week. ~ ost | Feed Heating Reduces Steel Power ; Significant Reduction in Fuel Consumption Using Multiple- ; Stage Condenser Heaters and Bleeding the Main Turbine BY LINN HELANDER” : ¢ |GNIFICANT reduction in fuel consumption, rela- ely greater than is obtainable in isolated cen- » al stations, can be made in steel plant power s by the use of multiple stage heating of the edwater. This involves replacing the common of heating the feedwater in an open heater : ries of closed heaters. Steam for heating the r then may be taken from the main turbine penings provided for this purpose in the tur- ng. In this way latent heat which otherwise wasted in the exhaust steam may be con Ale ‘i & p rs ‘ im When three heaters are used in series, com- ’ ree stages, the savings obtainable may range » 25 per cent of the fuel consumed in the yf power. ivings are large, as the quantity of steam a steel plant to heat the total feedwate1 % lable for use in stage heaters is large, relative a required by the power station alone. The re- Be of the blowing room and mill engines, as ose of the power station, must be met. This recovery of a larger proportion of the ; f the steam used in the generation of ce would be possible in an isolated power b [These savings may be gained with small 3 ense, provided the turbines in the power sta- be titable for bleeding. The use of closed heat- pe ivoids wasting steam and water, common with y heaters, and permits more ready de-aeration, a sary. The amount of feedwater treated or ee in consequence, will be reduced, with resulting e n operating charges and improvement in Rs eration. tion of Improved Economy from Stage Heating nonstrate the merits of various methods of e feedwater and of driving the auxiliaries, ‘es have been established for an assumed engineer Westir irgn rhouse Electric & Mfg. Ce 1s 1025 steel plant having steam-driven turbo-blowers, steam turbine completely electrified mill drives. balances were based on using, I, steam-driven auxiliaries and steam-driven river pumps, the exhaust steam in excess of that required to heat the feedwater to 210 deg. Fahr. being returned to the low pressure stages of the main turbine; II, steam- driven and motor-driven auxiliaries, with the steam- driven units loaded to supply sufficient exhaust steam to heat the feedwater to 210 deg.; II, motor-driven auxiliaries, with a house turbine loaded to supply suffi- generators and ; These heat we Heat C imption per Kwhr. for Various Methods of Heat- ing tl Feedwater and Driving the Auxiliaries The desig- n a) ilong the base indicate the method used to obtain heat balance 1 indicates single-stage heating and steam- driven auxiliaries, the excess exhaust steam above that re- quired to heat feedwater to 210 deg. Fahr. being re turned to the low pressure stages of the main unit B, steam-driven and motor-driven auxiliaries, with the steam driven auxiliaries loaded to give a feedwater temperature of 210 deg ind ¢ ngle-stage heating using a house turbine ind heating the feedwater to 210 deg., all auxiliaries being motor driver The numbers 1 2 and 3 indicate one, two ind three-stage eating to feedwater temperatures of 210 270 and 325 deg., respectively, bleeding the main unit and using all motor driven auxiliaries When bleeding the main init, dual drives are used on the condenser circulating pumps, river pumps and exciters, to assure continuity of service (Below) Reductior ir Fuel Consumption per Kwhr. by sing Stage Heating to give a Feedwater Temperature of 25 Deg. Fal \gainst Steam-Driven Auxiliaries Loaded give a Feedwate Temperature of 210 Deg The benefit from stage heating proportional to the quantity of water utes hat percentage reduction in heat consumed ! wl v na the gain from stage heating is credited } we ra s, will be directly proportional to the t wa 1 » that required for power uses alon This Irve based on ! assumption that when team rive 1x iris e used, load may be transferred t and to the te m-driven auxXiilary . E a4h < & A + A F 4 A ; - 4 A 4 i a J 7 x >» 7 Cc A \~ Y } ~ cient exhaust steam to heat the feedwater to 210 deg.; IV, motor-driven auxiliaries and bleeding the main unit to obtain sufficient steam to heat the feedwater to 210 deg. with single-stage heating; V, motor-driven auxiliaries, bleeding the main unit for two-stage heat- ing and a feedwater temperature of 270 deg.; VI, motor-driven auxiliaries bleeding the main unit for three-stage heating and a feedwater temperature of 325 deg. Summarized results of these heat-balance studies are given in the table. These data are based on a plant having a single-unit turbine generator which carries an average load of 15,000 kw. and turbo-blowers which require 120,000 lb. of steam per hr. The miscellaneous steam requirements are given in the table. Trans- former and line losses for motor-driven auxiliaries were 1024 THE IRON AGE April 12, 192: taken as 15 per cent of the power supplied to these in steel plants, probably will not meet wit auxiliaries. Steam of 325 lb. per sq. in. pressure and For emergencies or for starting up, inter 200 deg. superheat at the turbine throttle was used. of the auxiliary power supply with the main b Of the various methods of driving auxiliaries and probably will be necessary if auxiliary house g heating the feedwater, that which uses completely are used. Otherwise, heavy reactances to co steam-driven auxiliaries and provides for inducing the for phase shifts between the auxiliary genera excess exhaust steam to the low pressure stages of the oversized generators will be required. Intere turbine is the poorest from the viewpoint of fuel econ- with the main bus, however, is a recognize omy. It provides, however, the simplest and most’ which, particularly for steel mill service, s satisfactory method of controlling the heat balance avoided. when steam-driven auxiliaries are used. Compared Dual drives, that is, a motor and turbine mo with this method, the use of three-stage heating with a common shaft, for the essential auxiliari: a feedwater temperature of 325 deg. shows a reduc- motor drives for other auxiliaries, is probably ‘ tion in fuel consumption charged against power of satisfactory arrangement for steel mill servi 13% per cent, or a total saving of 40,700,000 B.t.u. per arrangement permits taking full advantage of hour when the boiler efficiency is 75 per cent. the main unit with adequate safeguard against With coal at $6 a ton, the money value of this’ tion of the essential auxiliary service. The du saving, assuming a combined load and use factor of permits normally driving the river and conde: 75 per cent, is $59,000 a year. With fixed charges culating pumps and the exciter by motors, so t against the capital investment of 15 per cent, this station under normal operation has the advant warrants an expenditure of $393,000. On the same economy of completely motor-driven au basis of comparison, two-stage heating, bleeding the Should disruption of the electrical service o HVUUCEDONNEEDURELUELAAOUEDEOORELINUEDUGGANUEEEREEDEEAEEOUEDUOOURDEEAEEUAROREAEEEHEEEE Comparative Fuel Consumption and Power Data For Various Methods of Driving Ausziliaries and Heating Boiler Feedwater of a Steel Plant Using Steam Turbine Generators and Steam Turbine-Driven Turbo Blo Initial steam pressure 325 lb. gage; superheat 200 deg, Fahr.; temperature of water entering first stage heater 75 deg. II III IV V Net station load in kw . 15,000 15,000 15,000 15,000 15,000 l Auxiliary load including river pumps, kw 1,400 1,465 1,650 1,650 1,650 1,¢ Gross station load, kw.... . 16,400 16,465 16,650 16,650 16,650 16, Load on main unit, kw a , 15,000 15,420 14,890 16,650 16,650 lt load on house turbine or steam auxiliaries, kw mr 1,045 LctO 02860 wees lg ees Condensate from main unit, lb. per hr 171,900 168,780 163,920 155,938 147,475 142 Condensate from turbo blower, Ib. per hr 115,000 115,000 .15,000 115,000 115,000 11 Steam for mud guns and incidental uses, Ib per hi LC WR Se eke ARO RS : ni 15,000 15,000 15,000 15,000 15,000 15, | Leakage, blow-off, etc., Ib. per hr.. : . 15,000 15,000 5,000 15,000 15,000 ) Total water heated, lb. per hr.. a 316,900 313,780 308,920 300,938 292,475 Total steam required for heating, lb. per hi $2,300 41,800 42,300 42,800 62,800 B.t.u. in exhaust or bled steam above feed temperatures 5 rr 1,011 985 950 95 950 Exhaust or bled steam available, lb. per hr 5 41,800 42,300 42,800 62,800 82,310 Kxhaust steam returned to main unit, lb. per hr oor ~ pees Jaen + eee!’ pie * Total steam per hr.......... bn tea D OR 359,2 355,580 351,220 343,738 355,275 369,400 Total B.t.u per hr supplied by boilers (thousands) ... ‘ Ne TP eT ee 411,284 407,139 402,147 393,580 385,473 380,48 Thousands B.t.u. from boilers charged against other uses than power..... bean a ba ace ko ee 184,700 184,700 184,700 184,700 184,700 Thousands B.t.u. charged against power per hr, 226,584 222,439 217,447 208,880 200,773 195,78 B.t.u. per kw. hr. at 75 per cent boiler efficiency 20,141 19,772 19,328 18,567 17,846 17,4( Per cent reduction in fuel charges compared to all steam driven auxiliaries, returning the excess exhaust steam to the low pressure stage of the main unit... .ccccsccasesecic 0% 1.8% 4.0% 7.8% 11.4% 13.¢ Note: I—AlIl auxiliaries steam driven: excess exhaust steam returned to main unit; feedwater temperatu 210 deg ¥F hr l1iI—Steam-driven auxiliaries loaded to heat feedwater to 210 deg Il1I—All auxiliaries n driven, house turbine loaded to give 210 deg. feedwater temperature. IV—Single-stage heating bleeding nm unit to give 10 deg. feedwater temperature V—two-stage heating, all auxiliaries motor driven, bleeding n init to give 270 deg. feedwater temperature. VI—Three-stage heating, all auxiliaries motor driven, bleeding ma un give >. deg feedwater temperature main unit, shows a saving of $50,000 a year; single- should other faults cause outage of the motors, stage heating, bleeding the main unit, $34,000 a year; turbines will automatically pick up the load. 5S! and single-stage heating with the house turbine $17,500 the turbines are used only for emergency service, th' a year. can be designed to have a simple and rugged const! Of the arrangements studied, that involving the tion, with low no-load losses. As these units aré house turbine would probably require the highest designed, no steam need be passed through them W initial investment, though in considering costs of this they do not carry load. nature, credit should be given to the house turbine for the equivalent main-unit value of its power generat- ing capacity. To compensate for the cost of heater Consideration of the improvement in economy, equipment required when bleeding, the size of the tained by efficiently heating the feedwater in multip* main-unit condenser may be reduced, with a consequent stage condenser heaters, is particularly importa”! lesser initial cost. If this is not done, the improved when comparing the operating costs of a steam economy obtainable because of better operating vacua bine driven power station and a gas-engine stat when bleeding than when not bleeding should be taken Heretofore, such comparisons have been based on 5!" into consideration. With not more than three or four gle-stage open-type feedwater heaters operating ineffi stages of feedwater heating, the piping complications ciently and heating the feedwater insufficiently to pe! with stage heating are not considerable. mit taking full advantage of bleeding the main un" As indicated by the tables, the fuel consumption tained with inefficient methods of heating the feedwa" Present-day tendency appears to be toward modify- and driving the auxiliaries may be reduced 15 ing the house-turbine method of providing assurance cent or more by using motor driven auxiliar! against disruption of auxiliary power, or the complete three-stage feedwater heating. elimination of this turbine. In place of it may be Future developments, now appearing likely 1 substituted house generators, coupled directly to the power plant practice, also should be borne in mi! turbine shafts of the main units, or dual drives on the is evident from Mr. Orrok’s paper given bef essential auxiliaries, such as the circulating pump of American Society of Mechanical Engineers, at 1's ue the main-unit condenser, the river pump and the ex- cember meeting, we are now in a position to evalue™’ citer. The boiler feed pump may safely be made motor- some of the future possibilities of steam power-P'®! driven. The use of auxiliary house generators coupled practice as indicating considerably higher efficiencie directly to the main unit, in stations of the sizecommon than are now obtained. These developments, when ‘"" Comparing Gas and Steam Plants Assurance Against Disruption of the Auxiliary Service ; no doubt will be of such a nature that THE IRON AGE existing ‘ 1 stations will be able to take full advantage of On the other hand, so far as is now discernible, 1ivalent evaluation of probable improvements in At ant practice can be made. present higher il efficiencies may be obtained in gas-engine sta- than in steam power stations. lowever, efficient bleeding of the turbines for feed- heating, and the use of higher steam pressures, materially reduce the advantages of the gas en- in this regard. Comparisons between the com- al economies, including capital charges, of gas- 1025 and steam-turbine stations should be based on steam stations deriving to the fullest extent practicable the advantages of high steam pressures and of efficiently bleeding the main unit to heat the feedwater. The steam pressures of the near future no doubt will approach 1000 lb. per sq. in., while four stages of feedwater heating is altogether practicable at the present time. These considerations make obso- lete such comparisons between steam stations and gas stations as heretofore have been published, unless they are accord with modern steam power-plant practice. engine stations rev ised to |l‘undamentals of Transmission of Power by Belting Pulley Grip and Elasticity Essential to Efficiency in a Belt Large Influence of Are of Contact ideal belt drive, in which driving at an angle, as much as 4 a favorable illustration of belt. isual ” ; ft tension of about 288 lb., with tl the belt BY runs hor | tally, pulling on the bottom, and in its modifica- ‘j- 5 deg., and ps more, the belt still pulling on the bottom, we ne belt in the value of elasticity Where the belt is put on the pulleys under a f rest, the tension is fairly divided between the trands of the belt (as illustrated in Fig. 1), pro- either shaft is free to revolve. f ordinary size, put on with belt occasioned by the clamps usually either of the shafts th ng an equilibrium between the one to o t revolve tension etween on the belt is divided them. the case of a very large belt, say a +} is might not be exactly true, bec: In the case clamps, of t] a 1e is sufficient + neavy + 1use It Yn ( le extent two stré yf main ° , over an engine and a long and heavy counter- mé 1\ possible to supply sufficient strain by the clamps slip the belt or to turn either shaft, so that strain of the clamps is not communicated to ier strand of the belt, and the tensions may differ. on the two strands in a state of re the same, W motion is applied, if he load on the is applied, that ly, though, in the case of smaller belts, the st is practi- bottom Si the belt be of leather, sions probably will be slightly changed, even } ie g slightly, and that on the top side decreasing But when a sufficient load is applied there occurs a complete change, the bottom side ng more taut, and the top side j increasing d becoming loose and dropping considerably in traight line drawn across the faces of the two \pparently, as in Fig. 2 2. the tension which this top strand in a state of rest has disap- nearly so, and its total s not more than that occasioned The tension on the bottom DY 1ts remaining tension own strand, however, increased by the application of the load, and the load may be is carried by this bottom ipon the adhesion of the there tension on t no longer is a he sit ng this load by the bottom strand depends, belt to the pulley, top le he belt in place. The belt is appreciably longer : t was when standing, and without this quality of y tary Leather Belting Exchange, Phila¢ lelphia, LOUIS W. ARNY adhesion, or pulley grip, simply would slide around the pulleys, and the tension on the bottom ply would be lost. With a good leather belt this tension, however, is not lost, because the pulley grip is of such intensity that the belt does not slide around the pulleys. It is obvious, then, that pulley grip is a dominant factor of And this particular pulley grip, that is, the ability of the belt to hold firmly, or transmission. to stick tightly, to the pulley, is a feature of fhe leather elt only, which other types of belting do not possess intrinsically. In belts without a natural pulley grip it becon necessary to supply a substitute, at least nt, and hence the use of sticky belt dressings, eh tension on the top side. PP $ it \ ind Re P 1 S for {hesion may be supplied for a é e appli m of “dope,” but any advantage fron ich application is only temporary. Those belts whi lo not possess the elasticity of the leather belt, and hence will not pull out, or elongate, on the top side a load, cannot rid themselves of their back pressure on that side. tension or Power transmitted by any belt is measured by the difference between the tensions of the top and bottom strands. From the total tension of the bottom side must be subtracted the total tension of the top side. If, to prevent the belt from slipping, it be necessary that the original slow running tension on the top side maintained, this must be deducted from the tension on the bottom side to secure the effective pull. This top side tension becomes a back pressure which the bottom side tension must overcome, and the mainte- nance of this tension, then, becomes a part of the cost of transmitting the load by this belt. If the same load transmitted by another belt without maintaining this tension on the top side, it is evident that it will transmit a larger load, or will transmit the same load at a less expense. Therefore the belt whose pulley sufficient to carry its load without slipping ex- shall be can be grip is cessively, and which has sufficient elasticity to elongate on the top side to an extent to cancel the tension of that side, will operate more favorably and more effi- ciently than the belt whose adhesion to the pulley must be maintained by a continuance of the tension on the top side. The factors of economical and efficient power trans- and must This, then, becomes a Those belts which possess mission by belting, therefore, are pulley grip elasticity, and any belt to operate efficiently possess both these qualities. measure of belt efficiency. « 233 “S oe — | on 1026 THE IRON AGE both of these qualities are efficient belts, and those which do not possess them both are inefficient. These points constitute the fundamental difference between leather and substitute belts. The grain or hair side of leather, properly prepared, makes a nat- ural suction contact with the pulley, which cannot be duplicated artificially in other materials. All substi- tute belts fundamentally are fabric, and fabric in any form is incapable of making this suction contact with the pulley, and is notably deficient in elasticity as com- pared with leather. The advantages of elasticity in the belt as above described are entirely separate and distinct from that other advantage of the increased pulley contact which TOP-ROLL BALANCING GEAR Electrical Instead of Hydraulic Operation in a German Design Though the screw-down mechanism of rolling mills yw commonly operated by electric motors, the bal ancing of the top rolls is in most cases actuated hy April 12, is a result of the elongation of the top side of th Pulley contact is one of the important factors of | transmission, and hence the more of the are < pulley that is covered by the belt the more will power transmission; and the longer and looser th strand of the belt may be the more of the arc pulley will be covered. The value of pulley conta a factor is in proportion to the degrees of are of tact. Some good authorities claim that it is greater, but this is a subject yet to be investig But it is evident that the belt which will run so ] on its top side as to cover more of the arc of the will operate more efficiently than the belt which less and roll is transmitted through the tubular worm-gear hub, and ball bearing to the mill casin housing, so that the main screw is carrying n whatever except the pressure of the rolls. A springs always press the breakers against the all slack is taken out and hammering is avoids remarkably quiet working of the mill even at his speeds is claimed. Large blooming mills are generally provided two motors to operate the gear. are coupled together and mounted hs —* { I> =| platform on top of the housing and 1) Spey od = . trolled by one controller. For bai } in ‘| 1 ae structural mills one motor is rega | | ~ a as sufficient. In order to stop the m } i ii) 7a panes quickly and positively and to secur: f "7 lt Motor | im curacy in adjusting the rolls, the m ' } is fitted with a powerful shoe-type bra (blast 3 st | be) | ie with gravity set and solenoid relea sie Hit | I¢ Ca Ie The operator is thus enabled to adjust — wr the rolls minutely and easily. The exact position of the rolls is indicated by a J | —| linear indicator and by a large dial grad bx +} =| ‘| — 8 uated in sixty-fourths of an inch. | | NN i = ad \y S&S = =) Se 1, = ‘~ The World’s Production of Tin | ! = The world’s production of tin in 19 =} was only 109,704 metric tons, the | | annual output since about 1908, 1 } decrease of about 16,000 tons from r r ; t in 1920, according to informatio - — available in the Department of t! 4 Fe terior. Of this amount the U! a, _ States, the largest user of tin ir \ S \ Ro hig eb aes world, consuming in 1921 more thar position, third of all the tin produced in that y Li d it down as Obtained from its own deposit only f u tons of tin, about three one-thousar of 1 per cent of the world’s output draulically. To eliminate the hydraulic device a bal- primary tin in that year, or about one one-hundr ancing gear has been developed in Germany and was of 1 per cent of the new tin needed in this cou recently described in Iron and Coal Trades Review, of In 1921 nearly all (98.50 per cent) of the wor London, by E. Krahnen, Duisburg, Germany. The screw-down mechanism is of the worm-gear type, acting on the square shank of the down screw, the sliding fit permitting of a free movement of the spindle axially. Around the protruding end of this square shank fits a tube having an external thread of the same pitch as the main screw, which, owing to the sliding fit, can move freely in the axial direction. The nut of this tubular screw takes the form of a cross- beam, to the ends of which are attached two rods form- ing the top-roll suspension. By means of conical spiral springs an even tension of these rods is assured suffi- cient to press the bearing against the breaker, elim- inating backlash. The cut shows the whole gear assembled with the top roll in its highest and lowest position respectively. As the pitches of the main screw and tube threads are equal, the movement of the down screw, suspension rods and top roll correspond, so that balancing of the roll is assured. For raising the rolls the motor is reversed. The tubular screw nut is raised, pulling up the connection rods and the attached roll. The entire weight of gear production came from the British Empire, the Du East Indies, Bolivia, Siam and China. The outstanding feature of the world’s production of tin is the | proportion of it that is produced within the British E pire—44 per cent in 1921. The Dutch East Indies duced 25 per cent, a notable increase in the fa adverse world conditions, and Bolivia only 18 per « nearly 10,000 tons less than in 1920. Siam and ‘ each produced between 5 and 6 per cent. The Nueva Montana iron furnaces, which ar leading industry in the city of Santander, closed several weeks ago. Since then the price of pis has dropped 15 pesetas a ton, leaving small | the furnaces being started up again in the near says Consul Maurice L. Stafford, Santander, Spa Current mechanical stoker sales are now re} by the Bureau of the Census. Reports were r* from fifteen establishments. In February 129 were sold for a total of 66,619 hp., while in Januar) the number was 145 and the horse power 83,270 [ Convention of Wisconsin Foundrvmen Cupola Practice, Use of Steel Serap and the Electric Furnace for the Steel Foundry Discussed at Madison. SNHE first annual convention of the Wisconsin Foun- irymen’s Association was held at the University f Wisconsin, Madison, April 4 and 5. The jance was 115 and 41 separate foundries were rep- d. This issaid to be the largest number of foun- which have ever been represented at a conven- ! n that State. An address of welcome was deliv- . by Governor J. J. Blaine. The program included \ tensive list of papers on subjects pertinent to the iry industry as well as trips to plants in the city, q iding the foundry and shops of the Gisholt Machine manufacturer of turret lathes and boring mills; French Battery & Carbon Co. plant; the United States Forest Products Laboratory and the Engineer- ollege Laboratories. The technical sessions were n the auditorium of the College of Engineering. resolution was adopted expressing the apprecia- of the association for the work done by the uni- y in connection with the convention and its offer e use of its laboratories and the assistance of its ical staff to the foundries of the State. A second ution urged cooperation to the fullest extent pos 4 e with all national associations having kindred in ts in the foundry industry. Officers of the association are: President, William Grede, Liberty Foundry Co., Wauwatosa, Wis.; first president, Scott Mackay, Stowell Co., South Mil- waukee, Wis.; second vice-president, Charles E. Schwab, R. J. Schwab & Sons Co., Milwaukee; third vice-presi- ent, E. M. Hanley, Chain Belt Co., Milwaukee; finan secretary, Joseph L. Wurm, R. J. Schwab & Sons Co., Milwaukee. Abstracts of the papers delivered follow: ery Selecting the Cupola Cupola practice was the subject of a paper read by \. W. Gregg, Whiting Corporation, Harvey, Ill. He ted out that there is a wide divergence of opinion » the best methods of obtaining good results in the 5 foundry. All practices followed, however, are for the Ee purpose of achieving the same end, that is, good iron. ce He defined good iron as follows: ; (1) Hot iron—hot enough for the work in question. 5 (2) Iron which will come from the cupola at a rate adapted to the handling facilities of the shop. fc (3) Iron which will insure castings free from slag shrinks and soft enough to be machinable at a ;: peed satisfactory to customers. a (4) Iron of the above characteristics, which can be luced with a minimum of expenditure for labor, r e and melting stock. - [he importance of cupola operation, Mr. Gregg 4 Was apparent from the fact that the average hot cost is not less than 40 per cent of the total cast b ( the finished product. Cupolas are built in sizes E nging from 12 to 120 in. in diameter inside the lin- although the smallest practical size is 37 in. in le diameter. A properly operated cupola will melt of iron per sq. in. of area per hr. The average f cupolas in use is the No. 6 with a 48-in. lining ter. This size will melt 8 to 10 tons an hr. e selection of the size of a cupola is determined daily melt desired and the length of time allowed The average small to medium foundry takes at a day and has the cupola in blast two to four In large production shops and continuous op- foundries engaged in automotive work iron is continuously. In those plants cupola operation be systematized to a nicety, and the output of ting department must be accurately balanced the production of finished molds. In probably e Last Week the largest automobile foundry, 30 No. 8 cupolas are in use, pairs of two of which are in blast while the other pairs of two each are being repaired ready to go in blast. This shop finds 12 hr. the most economical length of time to operate, although cupolas there have been in succesful operation for 24 hr. Correct Bed for Cupola Charge Melting takes place above the tuyeres and with proper operation, the bed of coke, the size of the iron charges, and the size of the intermediate coke charges should be so proportioned that melting takes place at the hottest point in the cupola. The location of this point varies somewhat with the volume and pressure of the blast and the kind of fuel used, but can be ac- curately determined by observation of the cupola lin ing after dropping bottom by noting where the greatest cutting and melting of the brick has occurred. In most cupolas this is 20 to 30 in. above the top of the upper tuyeres. To this point plus 2 or 3 in., the coke bed should be built. It is well to have a stick which will reach from charging door to the top of the bed and this should be used daily. Measurement should be made after the bed is lighted and all the wood burned away. Other points discussed by Mr. Gregg were the size and composition of the metal charge, proper charging, the amount of air necessary for combustion, the melt- ing ratio, single versus double-row tuyeres, height of charging door and slagging. On the subject of the composition of the charge, he asserted that silicon re- ceived the most attention, whereas carbon is more im portant. The total carbon should be determined in every gray iron analysis, for it is only when one knows the total carbon that one can predict the effects of silicon, sulphur and manganese in regulating the com- bined carbon, upon which the machinability of a cast- ing depends. Proportioning Steel Scrap in Charge The chemistry of semi-steel was discussed by J. E. Bock, Vilter Mfg. Co., Milwaukee. Gray iron of high quality having a tensile strength of at least 30,000 Ib. and transverse strength of at least 3200 lb., is made from mixtures containing from 10 to 40 per cent of steel, he said. Such a product is uniformly obtainable only when both raw materials and the finished castings are under continuous control. The most important factor in deciding upon the percentage of steel to be used in making a mixture is the thickness of the metal in the finished castings. The lightest sections ordinarily require 10 to 20 per cent of steel and the percentage is increased with increase in section, 40 per cent being the highest percentage feasi- ble under ordinary melting conditions. Almost any mild low carbon steel is suitable for use as steel scrap, provided it is available in pieces roughly of the same dimensions as pig iron. All steel scrap should be ana- lyzed in the laboratory for carbon, sulphur, phosphorus and manganese, which are relatively important in the order named. Pig iron, which makes up upward of 50 per cent of the ordinary semi-steel mixture, is analyzed in the same manner. The remaining raw ma- terial is usually scrap gray iron. Many foundries use any scrap which may be avail- able and do not hesitate to use as much as 50 per cent. For high grade work, however, when close adherence to analysis is required, not more than 25 per cent of gray iron scrap is used and some foundries limit themselves to the use of their own so-called semi-steel scrap. Proper use and control of alloys, coke, limestone, fire- 1027 - 1028 clay, fire brick, sands, as well as careful regulation of cupola practice are other subjects which were covered by Mr. Bock. The effect of various silicon, sulphur, phosphorus, manganese and total car- bon on the finished castings was also explained. Brass Castings Discussed Prof. E. D. Fahlberg, Department of Chemical En- gineering, University of Wisconsin, had as his subject the effect of metallic and other additions to brass. He that the behavior of brass when third metals are added is a matter of great practical importance to the brass foundryman; yet it is a subject which has not received the attention that it deserves from metal- lographists with the consequence that very little is known except a few empirical facts which are based almost entirely upon qualitative results. Professor Fahlberg briefly summarized the effect of both inten- tional and unintentional additions to brass, including tin, lead and iron in the first class, and aluminum, anti- mony, manganese, bismuth, arsenic, cadmium, silicon, phosphorus, copper oxide, zine oxide, aluminum oxide The lat- ter class of elements and oxides are considered injuri- ous to brass and to keep them below a necessary mini- mum the founder sort his scrap very carefully. stated and silica among the unintentional inclusions. brass must Giving Steel Castings Toughness of Forgings How to make steel castings as tough as forgings was discussed by L. R. Mann, Sivyer Steel Castings Co., Milwaukee. Although it is the common belief of steel consumers that mechanical treatment of the metal is essential to give it strength and toughness, it is pos- sible, through proper heat treatment, to give cast steel properties which are comparable to those found in the best forged steel. A preliminary requirement is the pouring into the molds of “dead” or thoroughly deoxi- For this reason the steel should be made, Such steel dized steel. or at least finished, in the electric furnace. has approximately the same specific gravity as forged steel; so any superior qualities that may be found in the latter must be due to more suitable internal structure. How the internal structure of cast steel may be altered through heat treatment so that it ap- proximates that of forgings was explained at length by the speaker. Arthur Hungelmann, consulting metallurgist, Chi- cago, delivered an address illustrated by lantern slides of micrographs, in which he emphasized the necessity of impact tests for cast steel. Frequently an improp- erly annealed casting will show well under a test for tensile strength. The only sure way of distinguishing between a properly and an improperly annealed steel is through an impact test under which a test bar is subjected to repeated blows. He showed on the screen a simple device used for this test. Basic Versus Acid Electric Steel Castings A. T. Baumer, Milwaukee Steel Foundry Co., Mil- waukee, Wis., compared basic and acid furnaces in electric steel foundries. At the outset he pointed out that it is far cheaper to operate an acid electric fur- nace than a furnace. The inside of the acid furnace is built up of silica brick and lined with ganis- ter, which may be readily patched. A _ basic lining consists of magnesite brick with a bottom of burned magnesite tamped with tar and is more expensive. The choice between the two depends upon whether quality or quantity production is desired. There is no question that basic steel is superior to acid. In the acid furnace there is an oxidizing condition at all times and it is impossible to make alloy steel with guaranteed results because the alloys themselves oxidize very quickly. In adding alloys in the ladles it is impossible to obtain uniform results. In basic practice, the alloys may be mixed in the furnace. In some respects the basic elec- tric furnace is like the basic open hearth. It is superior to the open-hearth furnace, however, because of the uncertainty of sulphur elimination in the latter. One difficulty in basic electric furnace practice is the ten- basic THE IRON percentages of AGE April 12, This can be by bottom pouring. dency of slag to get into the ladles. overcome, however, Material for Patterns Charles Jurack, Charles Jurack Co., Milw: manufacturer of patterns, spoke on the subject terns and pattern-making. Proper pattern equ he said, is exceedingly important and largely the production of foundries. Patterns may be into four classes: 1. One-casting patterns: 2. sionally used patterns; 3. Semi-production pat 4. Continuous-run patterns. The first class should be made as cheaply sible and should be destroyed after they hav used. The second class is the commonest and in patterns made from pine, cherry, mahogany or These require the greatest care because patter: subjected to greater strain in stores than in use. V patterns must not be allowed to dry out, as the) then warp when they get in contact with damp He cited an instance where $3,000 worth of ca were spoiled because the patterns had shrunk wood patterns will stand great heat, as they lo their sap at high temperatures. Patterns of the class are preferably made from pine because absorb and eject moisture and at the same tim the faculty of resuming its original shape after dented. Cherry is used for large flat surfaces, but the resiliency of pine. Mahogany will not di under different atmospheric conditions and also ha power of recovering its shape after denting. H wood or metal are generally used for patterns of last two classes, because of their durability. Class 4 patterns in the best practice are used in conjunct with molding machines. Unsatisfactory Bond Test for Sand Prof. J. F. Oesterle, Department of Mining and Metallurgy, University of Wisconsin, presented tables showing the results of tests of Wisconsin molding sands. The Parmalee method was used in the fineness test, while permeability was gaged by the time required for gas to pass through a column of sand. For bond the procedure was to ram up a bar 1x1x12 in. and push it over the edge of a plate, measuring the portion of the bar remaining after the end had broken off This test he regarded as unsatisfactory both because experiments with bars of different dimensions did not show like results and also because the personal factor was too variable. It is impossible to ram bars exact!) the same, and frequently hardness pockets in the bars cause fractures which give little indication of the true strength of the sands. F. J. Thibault, Ackermite Co., Chicago, addresse the meeting on the casting of lead-copper alloys. H stated that through violent agitation of mechar mixtures within a certain range of heats, his compan) successfully produced “ackermite” castings containing from 30 to 40 per cent of lead and 60 to 70 per cent copper up to weights of 1000 lb. each. The more violent the agitation at certain temperatures, the mor metal is broken up in the other. Others on the program were Dr. O. P. Watts, partment of Chemical Engineering, University of W's consin, who discussed electric furnaces for melting brass; C. E. McCampbell, Gisholt Machine Co., Madis whose subject was welfare; A. E. Hageboeck, Frat Foundries Corporation, Moline, IIll., whose paper W®> entitled “Advantages of Local Foundrymen’s Associa- tions,” and L. L. Smith, Kohler Co., Kohler, Wis., w” subject was foundry welfare and social work. / De Exhibition of Foundry Equipment and Supplies up An exhibition of foundry equipment and supp!les was held in the stock pavilion of the university. Phe exhibitors were as follows: Arcade Mfg. Co., moins machines, Freeport, Ill.; Carpenter Brothers, M waukee, dealers in foundry clays, sands and fire Dr Donald Sales & Mfg. Co., Milwaukee; Federal I‘ unary Supply Co., Cleveland; Fredman Bag Co., Milwauket American Foundry Equipment Co., New York; Herma" 12, 1923 — tic Machine Co., Pittsburgh; Industrial Core _ Milwaukee; International Molding Machine Co., Pangborn Corporation, Hagerstown, Md.; Jurack Co., patterns, Milwaukee; L. J. Pierson Co., blended and fluffed molding sands, Mil- George M. Pendergast & Co., foundry sands, ee: Whiting Corporation, Harvey, Ill., foundry John Mertes, dealer in foundry equipment hine tools, Milwaukee; Milwaukee Foundry t Co., Milwaukee; W. H. Pipkorn Co., fire clay and foundry supplies, Milwaukee; Brown & Co., pig iron and coke, Cincinnati; Wheelbarrow Co., flasks and wheelbarrows, Trucson Steel Co., flasks, Youngstown, esville Sand Co., molding sands, Zanesville, State Appropriations to Fight “Pittsburgh Plus” innesota legislature has appropriated $10,000 te the campaign against the “Pittsburgh plus” This action was taken by both houses with- ssenting vote. The house of representatives he measure April 3, while the senate acted on The bill places the appropriation in the a committee consisting of the governor and ney general, who will take such steps as they essary to bring about an abatement of the eh plus practice. The measure was vigorously d by the Minnesota Farm Bureau Federation, ith Commercial Club, the Minnesota Farmer Dealers’ Association, the Twin Cities Purchas- \gents’ Association and other agricultural and cial organizations in Minnesota. Minnesota is t State to appropriate money to fight “Pitts- plus.” April 7, the senate of the Iowa legislature uusly passed a bill appropriating $10,000 for impaign against the Pittsburgh basing point prac- c The bill will now go to the house for a vote. Increased Production of Magnesite in 1922 roduction of crude magnesite in the United 1922 was 32 per cent greater than that in It amounted to 63,487 net tons, valued at $650,- ording to figures compiled by James M. Hill, . 8. Geological Survey. Practically all the mag- ined in 1922 was obtained from deposits in a, though a little was mined in Washington he later part of the year, and some calcined was shipped from stock piles at Valley, q ligures showing the imports of magnesite since fF act of 1922 went into effect (Sept. 22, 1922) yet been published. The imports during the the year prior to that date amounted to 112,- as compared with 42,486 tons in the whole 21 No crude or calcined magnesite was ex- 1 in 1922, More than 90 per cent of the domestic magnesite i iced in 1922 was sold in the calcined form and P t from $30 to $50 a ton. The assurance of ces upon the passage of the new tariff act timulated the domestic industry. Many de- California are being reopened, and ad- equipment is being installed at calcining There is also renewed activity in the Stevens field, Wash. Aluminum Alloy Foundry Sands minary report to the joint molding sand ommittee on the conservation and reclama- ands in aluminum-alloy foundry practice has mitted by R. J. Anderson, metallurgist, De- of the Interior, Bureau of Mines. It has d that no attempts are made to reclaim used practice. A report on data submitted by foundries in reply to a questionnaire is in f preparation. THE IRON AGE 1029 IMPROVEMENT IN BRIDGEPORT Sustained Full Employment in Manufacturing Plants—Notable Feature BRIDGEPORT, CONN., April 7.—Manufacturing condi- tions in Bridgeport have been steadily improving for the last year, with very marked stability in the six months just passed. Figures handed to the Manufacturers’ Association compare the man hours with average factory hours. Thirty-one manufacturers have contributed data from their own factories. Based on an estimated normal of 25,318 employees, the employment in the week ended March 31 is 18,365 or 72.5 per cent. It is probable that the estimated normal is really higher than it should be, owing to the tendency to let war conditions of employment creep into and influence the establish- ment of such a so-called normal figure. This would in- dicate that present employment really bears a higher percentage of normal than would be indicated by the 72.5 per cent. Based on 18,365 employees the man hours are 791,- 642, or 63.8 per cent of the normal man hours of 1,240,- 582, which is based on normal employment of 25,318. Considerable improvement shows in the average factory hours put in, which indicates less time lost for various causes. For several months the average fac- tory hours have ranged from 48.9 to 50.1 per week on a base of 50 hr. Several exceptions were due to holi- days. For instance, the Good Friday holiday cut the week ended March 31 to 43.9, or 89.6 per cent. The week ended March 24 showed 50.1 hr., or a percentage of 100.2. This generally satisfactory condition of 100 per cent or better on average factory hours ha