The Iron Age 1939-07-27: Vol 144 Iss 4

FRITZ FRANK President VAN DEVENTER Editor ROWAN News Editor WINTERS Art Editor FINDLEY Editor Emeritus LIPPERT Metallurgical Editor Cc. E. WRIGHT Managing Editor MILLER Machinery Editor Associate Editors OLIVER Washington Editor Resident District Editors Pittsburgh Chicago Cleveland Detroit Editorial Correspondents London, England Cineinnatt FRAZAR FIDRMUC Boston Hamburg, Germany MEYER CHARLES Post Milwaukee San Francisco ASA ROUNTREE, JR. Birmingham Roy EDMONDS St. Louis SANDERSON Toronto, Ontario Leroy ALLISON Newark, N. J. TURNER, JR. Buffalo : Owned and Published by CHILTON COMPANY (Incorporated) Editorial and Executive Offices 239 West 39th Sr. New York, Publication Office ; Chestnut and 56th Sts., Philadelphia, Pa. OFFICERS AND DIRECTORS A. MUSSELMAN, President FRITZ FRANK, Executive Vice-President FREDERIC C. STEVENS, Vice-President JOSEPH 8S. HILDRETH, Vice-President GEORGE H. GRIFFITHS, Vice-President EVERIT B. TERHUNE, Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JOHN H. VAN DEVENTER, JULIAN CHASE, THOMAS L. KANE, CHARLES 8S. BAUR, CARROLL BUZBY, FAHRENDORF BAUR, General Advertising Manager DIX, Manager Reader Service Member, Audit Bureau of Circulations Member Associated Business Papers Indexed in the Industrial Arts Index. Published every Thursday. Subscrip- tion Price: United States and Pos- sessions, Mexico, Cuba, $6.00; Can- ada, $8.50; Foreign, $12.00 a year. Single copy, cents. Cable Address, ADVERTISING STAFF Emerson Findley, 621 Union Bidg., Cleveland B. L. Herman, Chilton Bldg., Phila. H. K. Hottenstein. 1012 Otis Bidg., Chicago H. E. Leonard, 239 W. 39th St., New York Peirce Lewis, 7310 Woodward Ave., Detroit C. H. Ober, 239 W. 39th St., New York D. C. Warren, P. O. Box 81, Hartford, Conn. Don F. Harner, 1595 Pacifie Avenue, Long Beach. Cal. Contents JULY 27. 1939 What Made the Dark Ages Dark? Spectrochemical Analysis Acme Laboratory Fuels for the and Steel Industry Role The Irvin Works Platen Fabricated Days New System for Fastening High Tensile Studs What's New Plant Service Apparatus the Assembly Line Washington News THE NEWS BRIEF Weekly Ingot Operating Rate Rate Activity Capital Goods Plant Expansion and Equipment Buying New Industrial Literature Products Advertised Index Advertisers Copyright 1939 Chilton Company 102 122 4 D. m al : : | id 18 d A n | > This Lewis Mill has all water lubricated bearings, three station water control rolls and bearings, special tables for han- dling special sheet bar, spindle carrier type top roll drive and balanced top roll. The mill shown the illustration special three high Lewis Mill which the custom- old two high stands were used basis for construction. operation now modification the standard Lewis Three High Mill providing important economies operation and production. Many operators can undoubtedly benefit such profitable reconstruction. consulta- tion with Lewis Engineers invited. E' 4 = JULY 27, 1939 Vol. 144, No. What Made the Dark Ages ITTLE Willie has inquiring mind and quite keen about filling his information tank. One day heard his teacher refer the period known the Dark Ages. raised his hand and popped question. asked, made the Dark Ages Little Jimmie, his classmate, was fond handing out information, right wrong, Willie was acquiring it. came his hand when teacher inquired any- one could answer the question. asked the teacher, made the Dark Ages And then this bit wisdom from Jimmie: "The Dark Ages were dark, because they didn't have any electric lights those not know what mark Jimmie got for his answer, but was not far from being the truth, you consider the electric light symbol mechanization and the fruit progress all branches applied science. course one might carry this thought extreme which would disprove the rule. But thoughts carried extremes usually get jumbled before they reach their destination anyway. One might say, for example, that electric light measure progress and culture, then Broadway, New York, between Times Square and Columbus Circle the most cultured and enlightened neighborhood the world. And there considerable argument needed before that statement would generally ac- cepted. However, those regions the earth which have the most electric lights, not merely concentrated areas but broadly spread—also have the highest standard living for their wage earners. For where you have electric light you also have power. And elec- trical mechanical power, measured horsepower, also seems measure the stand- ard living wage earners. Take the simple case the ability wage earners, various countries, obtain the world's most common luxury—cigarettes. the United States with 4.86 hp. per wage earner, the average hourly wage will buy cigarettes. Germany, with hp. per worker, will buy 30. Great Britain, with 2.56 hp., the hour's wage will buy 21. with 2.14 hp. per worker, hour's pay will buy only you see that the injunction there made the dawn creation, still And when anyone says: power indeed wishing you well. 3 3 | a ; BG Saving Weight and Fabrication Costs The many uses structural steel equipment well building construction offer numerous op- portunities for the services the Inland engineer prove real value. Weight often can reduced without sacrifice structural strength. Ease handling and appeal the buyer’s critical eye can often “stepped up.” The possibility saving tonnage fabrication cost leads sale price and net profit considerations, important competitive markets. Inland engineers offer broad experience such problems that will aid your staff securing the best possible results. Call your nearest Inland office for this service. Make use regularly connection with every use you may have for rolled steel any form. SHEETS STRIP TIN PLATE BARS PLATES STRUCTURALS PILING RAILS TRACK ACCESSORIES REINFORCING BARS ROBABLY there engineer- ing material use today that has closer limits its analytical specification than zinc-base die casting metal. Experience has proved that there are certain metallic impurities may present this metal such amounts cause intergran- ular corrosion take place. Especial- this true when castings made from this metal are subjected com- paratively high temperaturés and hu- midities. When the impurities this mate- rial are properly controlled, the cast- ings made from give excellent account themselves service. intergranular corrosion occurs and the castings are permanent their dimen- sions. unfortunate that experi- with the metal which was pro- duced some years ago left stigma which was hard overcome. Today, under careful manufacturing contro! and with the aid the spectrograph, tons this material are being cast castings are doing their part our “World Today” and will still doing good job the “World Tomorrow.” The elements which play havoc With die casting metal and TESTS all incoming zinc-base die castings for trace elements, such lead, tin, cadmium and magnesium. Much attention has been given increasing the reproducibility and accuracy such determinations, and lessen the time required for each test. The equipment used, the technique, and the results obtained are all described herein. ° MACKENZIE International Business Machines Corp., Endicott, the limiting amounts those elements are: Lead, 0.007 per cent; tin, 0.005 per cent; cadmium, 0.005 per and magnesium, between 0.02 and 0.10 per cent. few years ago would have been thought impossible control material such close limits, and the chemists would have had great difficulty mak- ing reliable analyses determine such small quantities impurities. When the demand arose for analytical meth- ods determine the impurities zinc and its alloys which would reliable, rapid and inexpensive, interest spec- trochemical analysis was given im- petus. Prediction regarding the use the spectroscope and its later form, the spectrograph, quantitative an- alytical instrument had been made. However, remained for the actual need for such methods arise before much real work was done. Great credit and Fuller for the very excel- lent pioneer work they did this field. Much owed them for the founda- tion the methods that are being used today the spectrochemical anal- ysis The purpose this article de- scribe the procedure employed the laboratories the International Busi- ness Machines Corp. increase the reproducibility and accuracy spec- trochemical determinations and les- sen the time required for such anal- yses. large Bausch Lomb Littrow quartz spectrograph used. The stand inclosed sheet metal hood which exhausted with fan, may THE IRON AGE, July 27, 5 4 The 5 | 9 Dig | No. RIGHT 2—Drili jig used for drilling spectographic electrodes. LEFT IS. An- other view the special fix- ture used drill elec- trodes. —* evenly spaced FULL VIEW seen Fig. The purpose the hood the are from the eyes the operator and prevent any possible pathological effect the operator from breathing air contami- nated the volatilized samples. danger probably quite remote, but the precaution well worth taking. sample taken from each ship- ment die castings received the IBM plant. Millings are taken from the castings, care being exercised not contaminate the sample. The mill- ings are thoroughly mixed insure representative sample and 6.66 grams are taken for analysis. After 3 \— 3 in ” hoo { >! CROSS SECTIONAL VIEW 4 tion 1-1 mixture hydrochloric and nitric acids, the sample made specially prepared graphite electrode. The matter selection the prop- sizes for electrodes important considerable wandering the caused when electrodes too large diameter are used. This overcome the IBM laboratories the use diameter electrode hold the sample and diam- eter upper electrode which sharp- ened ordinary pencil sharpener reserved for that purpose. The regu- lar grade spectrographic graphite electrodes used and they are not pre-burned before using. They are supplied 12-in. lengths and are cut lengths for use. The electrodes are drilled one end receive the sample, this being accom- plished the special fixture illustrated Early the work spectrochem- ical analysis the IBM Laboratories, was realized that reproducibility results was endangered the absorp- tion the sample the electrode. The porosity the spectrographic electrodes not uniform the depth which the sample absorbed varies. The writer believes that this will give non-uniform results and the labora- tory has overcome the trouble the impregnation the ends the elec- trodes used receive the samples with solution waxes. Many spectroscopists using solution methods have employed various ma- terials overcome the absorption the sample, among which are paraffin, mineral oil, collodion and others. has been found that none these worked well with the mixed acid solu- tion the comparatively high temper- ature which the samples are dried. was only after the trial many solutions that one was found which effectively prevents the absorption the zinc sample. The impregnant used the IBM laboratories solution grams Halowax No. 1014 and grams white beeswax c.c. C.P. carbon tetrachloride. Since this saturated solution room tem- perature must kept slightly elevated temperature while added the crater the electrodes. batch the electrodes impreg- nated set bakelite block and heated drying oven 103 deg. (217.4 deg. F.) until the electrodes are thoroughly heated. Immediately after the block and electrodes are re- moved from the oven two drops the 4 Cloth Ic. Is ‘countered. ae wax solutioa are added from glass stirring rod the crater each elec- trode. The drops are added one time, allowing the first drop soak before adding the second. The sec- ond drop requires minute soak and leaves film wax de- posited the walls the crater. The excess wax then removed and the walls the crater polished piece clean cloth wrapped around bake- lite rod such diameter that, with the cloth wrapped around it, can pushed into the crater with ease. This operation accomplished rapidly prevent this creeping and mush- rooming, ground graphite, prepared grinding the regular spectro- graphic graphite the pencil sharp- ener added the crater sufficient quantity that, when tamped down with glass stirring rod, just fills the crater. has been found best use those particles graphite which pass mesh screen, but not 100 mesh. The ground graphite absorbs the sample, holding the crater preventing the creeping. Electrodes which have the plates are processed and dried they are examined this type viewing box. mounting the electrode chuck the spindle small motor and press- ing the polishing cloth into the crater the electrode, shown Fig. Electrodes prepared this manner prevent the absorption the sample very effectively, but unless further pre- caution taken trouble may en- well known that zinc salts creep when precipitated out solution. was discovered that this characteristic was detrimental; for when the sample was confined the crater, the subsequent drying opera- tion the zinc salts precipitated out, they crept over the edge the crater and often down the side the electrode. They also would mushroom out the crater and, later, when the arc was struck part the sample would lost. 24—THE IRON AGE, July 27, 1939 pared this manner are then ready receive the sample. The sample introduced the electrode from the removable tip micro-pipette, shown Fig. confining the sample the center the electrode, the size the sample used has been reduced from 0.1 0.05 ¢.c. This represents 0.0166 gram the original metal. After the samples have been added the electrodes, which are placed the bakelite block, they are dried for least hr. the drying oven 103 deg. (217.4 deg. F.). has been found convenient, matter routine, set the samples late the afternoon and allow them dry overnight. this way they are ready burned the beginning the next day with lost time. Samples can dried less time matter check all samples are set duplicate. The drying oven located adjacent the spectrograph that one trode time can conveniently re- moved. Since zinc salts are highly hygroscopic, found that the loca- tion the oven important the samples rapidly absorb moisture from the air and would sputter the This causes loss sample and times will extinguish the arc left outside the oven too long. burning the sample, the electrode mounted the lower clamp the arc stand and upper trode centered directly over it. Since the graphite which has absorbed the sample more conductive rest the electrode, the are will cen- ter itself and will not start wander until the sample completely burned. Instead having burn for with sector disk interposed the path the light prevent the build- back ground and the attendant loss sensitivity, the sample com- pletely burned sec. using all the light. For the first sec. the burning period, amp. are Dur- ing this time the more volatile elements such tin, lead, and cadmium are completely volatilized. the end this period the current increased amp. The more refractory elements such magnesium, aluminum, copper and silicon are removed this tion. the sample consumed the current drops back amp. This sec., but all samples are burned sec. total time insure the complete removal all elements. When large number samples are burned daily, considerable saving time can accomplished burning only sec., compared with the min. burning re- quired older methods. The go” method quan- titative estimation used. Spectra standard samples containing the mini- mum and maximum magnesium con- tent with the maximum the impur- ities, lead, tin, cadmium and iron are photographed the same plate with routine samples. The middle range the spectrograph used which in- cludes that portion the spectrum from 2550 3550 Angstroms. The lines used for comparison for the vari- ous elements are follows: Magne- sium, the five magnesium lines from 2776.71 2782.99 inclusive; iron, 2823.28 and 2825.56; copper, 2824.38; lead, 2833.07 tin, 2839.99 and 3262.33; cadmium, 3261.05. this way all (CONCLUDED PAGE 66) | 4 q if on, o ACME LABORATORY metallurgical department the Acme Steel Co., Chicago, which not only furnishes tech- nical information regarding various types metals, but also coordinates the customer, the sales department, the planning department and the mill it- self, well quartered 6260 sq. ft. new laboratory space built January last year the Riverdale, plant, cost nearly $32,000. Aside from its physical and chem- ical testing functions which are car- ried out laboratories containing the best available equipment, Acme’s metallurgical staff under the supervi- sion Main, chief metallurgist since 1924, goes step further and actually acts intermediary, “go-between” for the mill and the cus- tomer, and the mill and its supplier. the first place, all slabs and billets are purchased the out- side. cooperation with its sources supply, therefore, specification sys- tems have been drawn up, that the metallurgical men all times know exactly the composition the steel that comes into the plant. Records are kept every heat and its analysis, and every slab billet each heat; thus, errors filling orders are un- likely and are easily checked when they occur. The employ views new air-condi- tioned metallurgical offices. upper left the general office where specifi- cation data sheets are filed. The phys- ical testing laboratory pictured the upper right, while the bottom the chemical section. cameras and their own dark room good advantage photographing sam- ples the various products for which the company supplying steel. this way record easily maintained the finished piece, while the original can cut and analyzed otherwise tested. Some these photographs file date back 1924 and still repre- sent items continuously supplied. Thus the proper type steel can recom- mended, the basis which speci- fication data sheet made out, con- taining laboratory observations and specifications instruc- tions. The laboratory then specifies these data sheets the type strip, the temper, edge, finish, steel specification, coating, tolerance promised furnished and any special mill prac- tices which may required. this manner the metallurgical of- fice records all data pertaining every single item ordered Acme’s many customers. means tele- type hook-up between the metallur- gical department, the hot mill and the main office the company Chicago, constant close check maintained all times. Every order received the main office starting through the hot mill checked against the files the laboratory. the specifications differ the order questioned and held un- til approval obtained. customer orders hot-rolled Acme Su- perstrip, in. 0.083 in. 103 in. When checked with the customer’s file, learned that this customer has been buying the same size steel for some time, but 108 in. long. Suspicion aroused because the similarity the two orders except the length. check immediately made, after hold- ing the order, and the sales department questions the buyer. discovered finally that the 103 in. length was error and that 108 in., filed the card, the correct length. Situated new air conditioned building, which also houses the plant offices, restaurant, and recreation facil- ities, metallurgical laboratory well equipped handle the ever increasing number duties that the metallurgists are being asked per- THE IRON AGE, July 27, 1939—25 nt A the iron and steel industry, con- sidered whole, fuel required for number purposes classi- fiable under two main heads, (a) for power production, and (b) source heat. many industries these poses must regarded absolutely distinct, but certain the larger iron and steel works the distinction less evident, such when waste heat, waste potential heat, available from metallurgical and allied opera- tions. smaller plants the distinction still remains and necessary, espe- cially part the whole the power requirements may purchased from outside. far the greater propor- tion the fuel, however, used supplying heat for metallurgical and allied operations. fact, unified works comprising .coke ovens, ore treatment plant, blast furnaces, melt- ing shop and mill, the whole the fuel requirements for power can supplied the surplus coke oven gas, blast furnace gas and waste heat from the melting shop. Fuel general may solid, liquid gaseous, and each type has its own particular sphere most efficient use- fulness. Each has its own advantages and disadvantages, but for many pur- poses gas often: the best and most convenient especially, because all fuels must gasified before they can burned with the production flame. Combustible gas, therefore, one step ahead the combustion process solid liquid fuels. Some processes plant, for reheating, heat-treatment, forge and similar furnaces, offer wide range for selection Others offer only limited range, for example the blast furnace which requires solid fuel. *Abstract lecture presented before the Staffordshire Iron and Steel Indus- try, Birmingham, England. 26—THE IRON AGE, July 27, 1939 For best results and economy fuel for the former furnaces should pos- sess the following desirable attributes (a) should easily distributable. (b) Its combustion should easily controllable from the points view atmosphere, temperature and flame length. (c) should free from constituents harmful the charge. (d) should capable high thermal efficiency and give flame tem- perature adequate for purpose. (e) should capable easy stor- age. view these attributes, the in- verse order suitability general fuels for this purpose is—coal, pul- verized fuel, fuel oils and gas. Coal Cheapest Selection, however, complicated such factors price, availability, etc., and must always remembered that when secondary fuels, that tar, tar oils and gas are prepared from coal, part the heat available from the original coal has ‘used di- rectly indirectly supplying the heat required for the conversion the coal the secondary fuel. far price per thermal unit the original fuel concerned, coal will always the cheapest fuel Great Britain, but possesses serious disad- vantages for ordinary metallurgical work. Among the disadvantages are: (a) not uniform fuel, chemi- physically. (b) possesses varying proportions non-volatile incombustible matter which seriously affect its burning properties, furnace, and after burning, the ash and posed of. (d) difficult control its com- bustion cope with rapid changes demand alter the condition and nature the flame. (e) The ash, some which finds its way into the burning gases, may harm the charge. (f) The smoke produced during periods incomplete combustion may constitute nuisance which may also aggravated the presence small particles ash. Many coals deteriorate storage. The advantages coal, however, are follow: (a) the cheapest form able fuel. (b) can easily stored without special provision expensive containers. (c) using primary fuel such coal the furnace not dependent upon the working ancillary plant the case, for example, producer gas. Some the disadvantages raw coal may overcome the use pulverized fuel. With the unit system pulverized fuel firing usually adopt- | | | | | | | | | 7 | | ° ° ed, where each furnace has its own pulverizer and the disadvan- tage bringing the fuel the furnace still holds, and many cases the ash problem still exists. Combustion, how- ever, more easily controlled. The development pulverized fuel firing for metallurgical furnaces probably the most interesting and important de- velopment during the last years this particular section the industry, giving rise flexible solid fuel, the flexibility being obtained expense grinding only and not gasifi- cation. Liquid fuels certain cases have several advantages over coal they are fairly easy handle. Great Britain, present, they are expensive. With certain mineral oils the ash present may have undesirable proper- ties and adventitious dirt may choke and burners. With tar, bad combustion may lead formation coke near the burners. The practice atomizing the oil with steam, while giving desirable combustion character- istics the oil-air mixture and also the flame, leads reduction American installations use pulverizer and distributing piping System. See Coal for Metal- lurgical Furnaces,” Herington, THe Jan. 19, Feb. 1939.— ° ° overall efficiency, and, course, re- quires supply cheap steam. Gaseous fuels for metallurgical fur- naces are ideal from the combustion point view and from other points view, especially convenience. Among the advantages gaseous fuels may (a) The fuel may prepared from coal central preparation plant and distributed each gas burning unit. (b) The gas can, necessary, puri- fied from constituents and give fuel unlikely damage the charge and with little distribution dif- ficulty. Gas burns without giving rise some the troubles experienced with oil, coal pulverized fuel, the ash prob- lem absent, burners are not likely clogged, etc. (d) The burning gas amenable easy control from the point view changes temperature, changes de- mand, nature the atmosphere and length flame. (e) Where high temperatures are re- quired, better thermal efficiencies can obtained than with solid liquid fuels the incoming gas can preheated regeneration recuperation much the heat the waste gases. (f) When properly prepared, gas much more uniform composition than the parent coal. The disadvantages gaseous fuels are, inter alia: (a) They are more expensive than coal, except where surplus fuel gas available such extent that can credited the producing plant only its coal-replacement value. (b) some cases where storage the fuel gas necessary, its storage becomes problem because the large volume occupied. Characteristics Rule Selection The selection fuel for use metallurgical furnace, controlled the first place the operation taking place within the furnace, involves knowledge the combustion charac- teristics the available fuel. Impor- tant properties this direction are: (a) ignition temperature, (b) limits inflammability, (c) rate flame propagation, and (d) flame tempera- ture, together with radiation from the flame and character the flame. TEMPERATURE: Whatever the fuel, whether solid, liquid gas, combustion cannot occur until the fuel has been heated certain mini- mum temperature, characteristic the fuel. other words, the temperature which heat generated burning faster than transferred the surroundings. Ignition temperatures air atmospheric pressures for gases commercial significance are follows: Hydrogen, 1075 1095 deg. Carbon monoxide, 1195 1210 deg. Methane, 1031 1290 deg. Moisture usually raises the ignition temperatures. Limits INFLAMMABILITY: For each fuel gas there are definite upper and lower limits composition the gas-air mixture beyond which the mixture will not ignite and continue burn. The limits vary with the gas, the temperature and pressure. For the gases involved ordinary industrial heating, ordinary temperatures and THE IRON AGE, July 27, 1939—27 ab : atmospheric pressure, the limits are follow Hydrogen, 6.2 71.2 per cent. Carbon monoxide, 16.3 71.4 per cent. Methane, 5.8 13.3 per cent. The gas-air mixture therefore, must within the limits inflammability and must heated certain mini- mum temperature before combustion can RATE FLAME PROPAGATION: This important, especially the design burners and furnaces, since the gas velocity entering the furnace must greater than the flame velocity, other- wise back-firing will occur. Flame speed varies with the gas-air propor- tions and with the diameter the tube vessel which the flame produced. FLAME TEMPERATURE: present there does not exist satisfactory method measuring the temperature flame. For comparison purposes the so-called theoretical flame temper- ature used. Flame temperatures gases industrial significance are, air, follow: Hydrogen, 3934 deg. Carbon monoxide, 3934 deg. Methane, 3722 deg. The theoretical flame temperature can increased preheating the in- coming air and/or gas. the air preheated 1112 deg. F., the value increased from 3934 deg. about 4712 deg. F., and both the air and the gas are preheated 1112 deg. the theoretical flame temperature in- creased 5072 deg. The flame temperature affected also excess air, moisture, content the air, etc. The burning raw coal takes place least three stages, namely dis- tillation volatile constituents from the green coal, burning the volatile matter, and burning the so-called fixed carbon. Except, therefore, furnaces fired mechanically with well- sized coal, there lack uniformity the fuel bed, the draught distri- bution the excess air, the flame condition and properties, etc. Where ‘additional expense warranted suitable gaseous fuel more conve- nient. Coke oven gas and town’s gas are obtained destructive distillation coal and are very similar most re- spects. When prepared, they represent only small proportion the original coal, the major yield being coke. cordingly, far their application furnace heating concerned, they are useful only when supply avail- able from, for example, coke works 28—THE IRON AGE, July 27, 1939 where coke being prepared for metallurgical purposes. Producer gas the most popular gaseous fuel the iron and steel in- being obtained the regulated par- tial combustion suitable coals cylindrical producer. Coke may used instead coal but the former gives gas lower calorific value than that obtained with mechanical coal producers. Water gas obtained the applica- tion steam red-hot coke not much used for furnace heating, al- though finds useful application for certain types welding. Blast furnace gas, when available, offers useful fuel for certain types work where very high flame tem- perature not required. The fuels greatest interest the iron and steel industry whole are, therefore, coal, coke, coke oven gas, producer gas and blast furnace gas. The selection fuel for particu- lar operation governed (a) the operation itself, and (b) the avail- ability the fuels. For convenience the fuel consuming units industry may divided into the following (a) Coke ovens for fuel, for (b) the blast furnace. (c) Melting furnaces requiring tem- peratures above 2912 deg. (d) Reheating and treatment furnaces where lower temperatures are required. Fuel for Coke Ovens coke ovens situated collieries the usual fuel neat coke oven gas distilled from the coal. such cases modern plant, less than per cent the total make gas re- quired for heating the ovens, leaving over per cent available for other purposes. The flue temperature re- quired coke oven work seldom ex- ceeds 2192 deg. F., and such tempera- tures can easily attained with gas lower calorific value and intensity than coke oven gas. Where use market exists for the higher calorific use heat the ovens. Accordingly, lower calorific value gas avail- able, often good policy have the oven heating system designed that either low high heating power gas can used efficiently. Blast furnace gas, calorific value around 100 B.t.u. per cu. ft., is, preheated addition preheating the air, suitable fuel for coke oven heat- ing and its use plants attached ironworks increasing. such cases the whole the make coke oven gas available for melting shop work, etc., where, mixed with blast furnace gas, forms useful substitute for coal producer gas. Producer gas made from breeze screened from the coke affords further low heating value for coke ovens. Such producer gas heating does not appear very popular Great Britain for coke ovens, although often applied gas works for heating the gas retort settings. The use low calorific value gas for coke oven heating has, course, certain disadvantages, due first all the low heating power the gas which, well the air, has preheated before combustion order give the necessary flue tem- perature, necessitates special design regenerators and flues; and, secondly, the large volume fuel gas and flue gas dealt with. Gas Mains Vary with the use low calorific power gas the size the gas mains em- ployed. Coke oven gas, for example, contains about four and one-half times many heat units equal volume blast furnace gas. gravity blast furnace gas about twice that coke oven gas. There- fore, the friction loss the flow equal volumes about two and one- half times much for blast furnace gas for coke oven gas. That is, for equal volumes blast furnace gas main must about per cent greater diameter than for coke oven gas, and for equal units heat the blast furnace gas main must have diameter about two and one-half times that the coke oven gas main. cordingly, blast furnace gas should used near the blast furnaces possible and handled little sible. The blast furnace plant, addition requiring fuel for the furnaces themselves, requires certain amount fuel the treatment and tion plant the in-going ore. The blast furnace plant proper greedy plant far fuel concerned. De- pending upon the burden, and certain extent upon the coke itself, the blast furnace requires anything from 1600 1800 3000 Ib. coke per ton iron made. The actual coke consumption depends upon many tors, some which are follow: (a) The coke itself, that its physical composition, chemical composition, (b) The composition the burden. (c) The grade iron being produced. (d) The type slag required. (e) The size the materials charged. 4 q ed. ed. q q (f) The size uniformity the mate- rials charged. (g) The size distribution the ma- terials within the furnace controlled (e) and (f). (h) Order charging the coke and ore. (i) Temperature, pressure and humid- ity the blast. (j) Furnace design. (k) Weather and wind direction. (1) Condition the furnace. (m) Personal factors, may mentioned the con- victions the best method han- dling the furnace, and the experience the furnacemen. Blast Furnace Combustion Poor Considered separate unit, the blast furnace has poor combustion that the waste gases are combustible. The better the furnace working the lower the proportion combustible gas the top gases. There limit, however, the ratio obtainable the top gases and the limit any given time gov- erned the dynamic chemical equi- libria obtainable within the stack under the running conditions. the other hand, the top gases, which should leave furnace which working well around 212 deg. F., can put good use properly coordinated works and are not wasted, and with the po- tential heat recovered from the gases using them fuel, the blast fur- nace becomes efficient unit from the combustion engineer’s point view. Melting furnaces require fuel high flame temperature. many works, probably most works, the fuel gas open hearth furnaces pro- ducer gas made from suitable coals, the gas being used hot and without There tendency, where convenient, replacing producer gas suitable mixture blast furnace gas and coke oven gas. The gas unified works may obtained from the coke ovens, may purchased certain districts from neighboring coke oven plants. changeover from coal producer gas coke oven-blast furnace gas mixture sometimes leads trouble, especially with burned roofs, due the different combustion char- acteristics the mixture ducer gas. Ordinary reheating and other simi- lar types metallurgical furnaces not require fuels with such high flame temperatures. Accordingly, practically any fuel may used suitably ap- plied. many mills, situated more less unified works, blast furnace used cheap and convenient fuel for soaking pits, reheating and annealing furnaces. mills and works not attached large works, coal, coke oven gas, producer gas, tar oils, fuel oils and pulverized fuel may used. Such fuels may, course, also used even unified works and there one works where, when coke ovens were closed down, some the metallurgical furnaces were heated means producer gas, some blast furnace gas, some fuel oil, and others pulverized fuel. some sections metallurgy elec- trically heated furnaces are used. the object all within the iron and steel industry produce the best product the lowest price, and every- one engaged the industry is, directly indirectly, striving reduce pro- duction costs. Fuel costs form very large item iron and steel metallurgy, and often toward fuel that atten- tion turned for reduction costs. The possible saving fuel has course been recognized almost since the inception the industry and has crystallized into fuel economy. Fuel economy the first place bound up, not much tracing small leakages heat, but intelligent se- lection and use fuel and burning appliances. Where selection fuel and burning appliances limited, then fuel economy becomes question the best use the available fuel under existing circumstances. industry such the iron and steel industry, fuel economy concerns not only each unit and each process but also coordination between the dif- ferent types plant and processes employed, even when they are not the same site. Most the coal used the iron and steel industry for the making coke for use blast furnaces. Fuel economy and conser- vation, therefore, effected the blast furnace will reflected all iron and steel products. The average coke consumption per ton iron made has decreased during the last years, but there still room for considerable improvement. Ash Removed But fuel economy the blast fur- nace does not begin home—it begins the coal mine and the ore mine. Not very long ago coke ovens formed sort convenient refuse de- structor where unwanted coking duff, screened from the much more easily saleable and valuable larger coal, could converted into saleable coke for blast furnace use. those days the duff was not washed before carboniza- tion and the resulting cokes contained high proportions ash. The practice washing such duff before coking now almost universally applied, but only comparatively recently that the practice has become general. Colliery slacks, before washing, may contain anything per cent ash and sometimes more. may washed and the size most suited coking may washed down around per cent ash lower, but seldom cleaned below per cent. The corresponding large coals from which the coking duff has been screen- often contain much less than per cent ash, and pity that the in- dustry cannot afford use the cleaner large coals. might worth the in- dustry’s consideration, however, produce still cleaner coking duff rewashing give two products—first super-clean duff for producing low ash coke and second, somewhat higher ash material suitable for use under boilers. Modern research coal cleaning gradually introducing more efficient washing, but must pointed out that the degree cleanliness freedom from mineral matter obtain- able function the ash distribu- tion within the coal itself, and some coals are much more difficult wash than others. Ash Cost High can shown that, with coke consumption around 2500 per ton pig, additional one per cent ash increases the coke consumption direct increase production costs around per ton. But extra ash the coke necessitates extra flux- ing materials, thus reducing the amount iron the burden, causing reduc- tion furnace capacity, reduction output increase slag formation and therefore greater volume slag handled, increased transport and han- dling costs for coke and, usually, low- ering the quality the iron. difficult assess the extra cost thus involved but will probably around 18c. per ton. One per cent extra ash the coke, therefore, involves in- crease cost iron production about 3lc. per ton. Conversely, re- duction one per cent the ash con- tent the coke would lead reduc- tion cost production amounting 3lc. per ton. coke quality varies much that the ash content varies from per cent over per cent, then using the dirtier coke, the cost iron produc- tion will least $1.50 per ton more than with cleaner coke. This does not take into account the effect the mois- ture the coke. The smooth running the blast THE IRON AGE, July 27, 1939—29 | ort rst ly, le, fic re- 1e- cal furnace not only determines large extent the overall fuel economy iron and steel production, but also influences the cost semi-finished and finished products. Smoothness running the furnace almost always reflected coke consumption. For best results, far the coke concerned, the washeries and the coke ovens should their combined efforts provide the blast furnace with the best possible coke. Unsized Ore Used The road fuel economy can often process plant from point view not directly associated with the fuel itself. The blast furnace provides useful example, but the general idea can applied all metallurgical operations. The ore charged into the furnace has very important effect the fuel consumption the furnace. many districts the ore charged wet—it may may not broken. Even works where the ore broken, unusual, Great Britain, for the whole the common sight see pieces ore weighing over 100 Ib. being charged into furnace. Where unsized ore and coke are used, segregation bound occur within the furnace. The amount segregation well the ultimate distribution will dependent certain extent upon the method handling the materials before they reach the bell. The ordinary bell, how- ever, seems exert the greatest in- fluence the ultimate distribution which would depend upon, among other things, the bell diameter, throat di- ameter, angle bell, bell-drop, dis- tance from bottom bell top stock, amount material the bell, order deposition coke and ore the bell and the shape the interior the furnace top. Ore Moisture Expensive Where there mal-distribution stock far size and also chemical composition concerned, gas-stock contact-times will vary across any given plane. This reflected gas compositions and temperatures. the gases any blast furnace stack are fully utilized there rea- son all why top gases with ratios below should not regularly obtained together with marked decrease coke consumption. This can only attained uniform distribution the materials within the stack, possibly very tall stack. 30—THE IRON AGE, July 27, 1939 smooth running the blast furnace not only but also influences the cost semi-finished and finished and possible some degree drying the ore prior But tall stacks have not been success- ful. the ores and coke are charged with wide size range, then atten- tion charging devices and design the furnace top might insure better size distribution within the furnace. Such step, however, would only palliative, the real cure break the ore, screen out the fines, and charge only sized material. Inciden- tally, the practice charging unduly large pieces scrap not likely improve furnace working. The question the moisture the ore charged does not appear have received due attention. Where the ores have conveyed rail long rye er distances, seems pointless carry with the ore, often occurs, large quantities water. From the point view transport alone, the actual ore capacity cars reduced and freight charges water are the same those ore, and literally thousands dollars are being spent annually carrying water entangled with ores from the mines the furnaces. ores cause trouble storage bins and hoppers, breakers and the furnace bell, etc. They lead the production wet top gases they are responsible for high gen-content the top gas with | 4 the overall fuel economy iron and steel production, charging England. arry arge and ame ores Wet and and dro- cor- tive this direction, breaking the stone may help, since the water reach- ing zones hot enough for the steam- carbon reaction occur must have been retained the larger lumps ore. such lumps burst hot zones, then there will local high concen- tration hydrogen. Breaking the stone, however, far from the com- plete answer, although would also help that size distribution would better, because with bad size dis- tribution lump descending the fur- nace might suddenly from zone 750 deg. F., zone 1500 deg. Sudden divergence very hot gas passing through zones consist- operation requires the best possible coke, sized ore, Photo shows furnace being tapped the plant Barrow ing mainly the larger pieces bur- den cooler zones where the smaller sizes preponderate would account for very rapid alterations temperature one point, and also, certain extent, the incidence the water- gas reaction. Partial Drying Suggested The cure dry the ores, partially any rate, before charging them into the furnace. Blast furnace gas could used for this purpose, possibly flue gases from the combustion low grade coal. For best working blast furnace, regularity and uniformity raw ma- terials would seem more than highly desirable, but few blast furnace operators are blessed with such uni- formity. Coal treatment now prac- ticed with benefit both supplier and user. Ore treatment practiced before metallurgical treatment minerals other than iron ores, but the lower value iron ores, especially the low grade ores found Great Britain, seems have deterred producers from spending much money their treat- ment. This mistake, for every penny spent ore treatment outside the blast furnace, 4c. would saved within the furnace, apart sequent savings other parts the works, because uniformity product from the blast furnace will reduce steel making costs and probably also rolling costs, especially from the point view defectives. For fuel economy any plant, necessary know exactly what hap- pening that losses heat and effi- ciency may checked soon they arise. This calls for the provision adequate recording instruments, for without their aid fuel and efficiency losses occur without detection. Pro- vision instruments always eventually leads reduction defective material they afford means process control well control process conditions. Coal mainstay the iron and steel industry. Nationally, well industrially, should used the best advantage all concerned, whether coal, coke gas. Managers the various units iron and steel works have much they can keep their respective units working satisfactorily—they have not the time they would like devote the problem fuel economy and fuel conservation their own particular unit. Accordingly time has seen the gradual introduction sepa- rate fuel departments whose job keep eye fuel consumption, suggest where savings can made, coordinate fuel usage between de- partments, etc. submitted that the industry would benefit consider- ably the introduction greater number people who have received first class training fuel technology, which includes the proper study not only the application coal, coke and the country’s industrial needs, but also training the funda- mentals use all solid, liquid and gaseous fuels. Fuel economy any works cannot efficiently attained without the aid properly trained men. THE IRON AGE, July 27, 4 q j q modern mill not con- glomeration isolated units slapped together and roof built over it. highly coordinated pre- cision machine. Its success depends upon the uninterrupted flow steel through it, and the utmost coordi- nation required between operating departments, mill builder, electrical manufacturer, building designers, con- structors, and the myriads contrac- tors supplying lesser parts the equipment, the result satis- factory. after completion today, more than ever before, are cost- ly. Everything must planned, from the location the largest mill hous- ing, that the smallest control switch. natural, therefore, that steel’s most modern hot strip mill, the new Irvin works the Steel Corp., should present inter- esting study. triumph mod- ern engineering and not “just another hot strip but presents many interesting features. First, unique that country- side hill was chiselled out and mill was built “from the ground Next, its gigantic size presented new and interesting problems, and the careful layout and perfection detail also bear consideration. Then, the degree which equipment was completely assembled the factory presents Last, but not least, safety men and equipment has been given the utmost attention. The main drive motors, totalling 42,250 hp., represent the greatest IRON AGE, July 27, 1939 this description the electrical equipment for the 80-in. Irvin continuous mill, the writer brings out three points: The vast amount intricate engineer- ing that preceded the first step construction, most the results which are invisible the casual observer; the unprecedented extent which factory assembly was used for the vital equipment above and below stairs; and the inspiring greatness this producing unit—a symphony power under iron- hand-in-velvet-glove control. power ever applied hot strip mill. total 15,250 hp. 6600 volt, cycle slip ring (wound-rotor) induc- tion motors drives the scale breaker and four roughing stands this 80-in. wide mill, and the accom- panying table shows the motor ratings, gear ratios, speeds, etc. The roughing stands are placed that the largest slab can only one stand time, making unnecessary synchronize these drives. The six finishing stands are set centers, and are driven 27,000 hp. adjustable speed 600 volt d.c. motors. For details, see accompanying table. Each motor designed for per cent speed regulation from no-load full load throughout its respective speed range, and has maximum load rating 200 per cent top speed, with the exception No. stand, which has maximum load rating 240 per cent top speed. The delivery speed from stand No. 1005 2010 ft. per min. Nominal annual production 600,000 tons. Power for the finishing stand drives furnished three 7000-kw., 600 volt motor generator sets, which are the largest ever supplied for hot strip mill. Each set, which consists two 3500-kw. generators, driven 9600- hp., 6600 volt synchronous motor 360 r.p.m., designed for 200 per cent maximum loads. The operators control the drives from two elevated pulpits, over- looking the operating side the mill —one the roughing end, and one the finishing end. Not only has great care been used the location and sign these pulpits that the ators have clear view the mill, but equal care has been used locating every control switch and instrument for the venience and natural motions the | f 0 0 a 0 1 ° ° ° 7 THE IRVIN WORKS... operator. The control bench boards desks are narrow possible, the operator does not have far move reach any switch read any instrument. The switches and instruments are arranged the same sequence the mill. Those used most frequenfly are the handiest positions. Every con-