The Iron Age 1921-03-31: Vol 107 Iss 13

STABLISHED 1855 VOL. 107: No. 13 ee Flexibility of Output Assured In Seullin Mills New Type of Adjustable Speed Drive for Mer- chant Mill and Combination Structural and Blooming Mill Aids to Diversity in Production BY GILBERT L. LACHER CONOMICAL production in any plant implies a maximum use ,of manufacturing facilities and hence a minimum overhead. Intermittent periods of idleness are expensive because fixed costs continue to accrue whether a works be inactive or running. It or this reason that plant managers try to balance their business and diversify their products in such a manner as to insure continuous operation. Efforts in this direction have been hampered, in the case of manufacturers serving the railroads, by irregularity of buying. It has been feast or famine. Either the carriers are vying with each other in their efforts to secure new equipment, or they are all in the market for practically nothing. It is not surprising, therefore, that one of the larg- est producers of steel castings for railroad rolling stock should expand the scope of its business to ir lude products for which there are other markets. Th: nills completed and put into operation by the Scull Stee! Co., St. Louis, late in the fall of 1920, supple nent the foundries which previously were the sole yutlet for the steel produced in the company’s open hearth furnaces. Steel from the furnaces may now be poured into ingots for rolling or into steel cast- ngs, as required. If at any time the joint consump- tion of the foundries and the mills should exceed the capacity of the furnaces, extensions to the open-hearth plant have been arranged for. The flexibility of this arrangement commands atten- No less impressive is the degree in which the ew mills are equipped for a diversity of products and a maximum use of rolling capacity. The smaller of the company’s two mill buildings contains a 16-in. oughing mill and a five-stand 12-in. finishing mill. The latter is operated by an adjustable speed motor set which permits of the rolling of light sections of merchant bars at a higher rate of speed, thereby in- suring a tonnage production which will compare favor- ably with the output of the heavier sections for a like period. The adjustable speed drive, operating on alter- nating current, differs from previous types in that it has a speed range extending from below and through synchronism to a point above, and the torque varies in- versely with the speed. To increase further the adapt- ability of the merchant department, the company pro- poses to add a 16-in. finishing stand in which material nay be f shed direct from the 16-in. roughing stand. The i} equally interesting from the \ ! k s | lé 22-i1 Mill I Uncoupled Other Stands, It Ma te Used as a Billet Mill ng middie roll, operated hydraulically ee Se ee em 830 THE IRON AGE An Ingot Passing from the Delivery End of the Reheating n the roller table At right standpoint of flexibility of output, as it may be em- ployed either for the production of finished shapes or billets. The first of the four three-high stands is equipped with a floating middle roll so that it may be used as a separate billet mill when desired. Throughout the plant are evidences of close atten- tion to details which make for economical production. The layout with reference to the receipt of materials and the shipment of finished products is such as to eliminate handling. In the roll shop, equipment has been provided to insure a maximum unnecessary output of work per man. The water circulation sys tem is noteworthy because of the utilization as a cool- ing tank of the valley in the roof of the bay connecting the mill buildings. The electric sub-station is a model of up-to-date construction, complete equipment and proper insulation of apparatus. For the convenience and protection of the mill hands the company has pro- March 31, 19 Furnace. The ingot turner, just behind the ingot, is locate: is an up-cut hvdraulic.shear vided a “first aid’ room and the best of toilet, wash room and locker facilities. An unusual feature of the 22-in. mill of the Scullin plant lies in the fact that it may be used either for the rolling of billets or finished material. It consists of four three-high stands served by two pairs of traveling tilting tables. The roughing stand, which contains an hydraulically-operated floating middle roll, such as is used in three-high plate mills, may be uncoupled from the other stands in 15 min. time and, operating sepa- rately as a billet mill, roll billets for use in the 12-in. mill. The stand may be used as a bloomer when rolls are being changed in the other stands, or at any other time when the finishing end of the mill is idle. All four stands, together with the electrically operated tilting tables, were built by the United Engineering & Foun- dry Co., Pittsburgh. The mill is operated by an 1800-hp. Westinghouse Connected with the 22-In. Mill by Flexible Coupling and Herringbone Gears, the 1800-Hp. Three-Phase Induction Mot of Heavy Steel Mill Type, Maintains Constant Speed a oes ch 31, 1921 int speed induction motor of heavy steel mill type, ¢ three-phase 25-cycle current at 2200 volts. The r, which is connected with the mill through a flex- oupling and herringbone gear unit, operates at m. By gear reduction the mill speed is brought to 68.6 r.p.m., corresponding with a rolling speed per min. The pinion shaft is mounted with ; fly-wheels, nine feet in diameter and weighing lb. each, one being overhung on either end of ; haft. mill rolls billets, channels, angles, beams, es, rounds, flats, or light rails direct from 12 x 2350-lb. ingots. These are poured from 12. oil- 35-ton open-hearth furnaces, located in the foun- init of the Scullin works, two-thirds of a mile y. The combined capacity of the furnaces is 15,000 : 18,000 tons per month, as compared with a rolling ty in the mills of 10,000 tons. rom the open-hearth plant the ingots are conveyed ympany rails into an open bay between the two lildings. Here they are transferred by overhead ng cranes to a charging table, from which they ided one at a time onto a roller table, operated ‘0-hp. Westinghouse motor. The rollers delive rot to position at the end of a flat arch, water- continuous, oil-fired reheating furnace. A ram, i by rack and pinion from a 20-hp. Westing- notor, charges the ingot into the furnace, and ing pushes another out at the delivery end. ts are charged in a double row and are pushed the furnace on water-cooled skid pipes. The the furnace hearth is 46 ft. 3 in. and the 15 ft. Heat is supplied by eight oil burners. ‘urnace patterns and castings were made in the foundry and construction work was handled by the company’s own force. A feature of the construction is the fact that its bottom has 4 *n eevated above the level of the pull-over table on n side of the mill, thus permitting long pieces THE IRON AGE 8: we _ in the process of rolling to run under the furnace and beyond the end of the building. Ingots are charged into the furnace practically cold. When the mill is operating, as many as 25 ingots an hour, or about 25 gross tons, are reheated. From the reheating furnace, the ingots are deliv- ered to a roller table which carries them to an ingot manipulator, where every other ingot is turned so that all are fed to the roughing stand with the small end first. When billets are rolled on the first stand, they are delivered directly by roller table to an hydrauli- cally-operated up-cut shear equipped with a motor driven gage for cutting lengths desired; thence they are transferred by an hydraulic kickoff down a skid chute to a billet conveyor which deposits them in a cradle located in the open bay between the two mill buildings. The cradle is lifted by an overhead travel- ing crane and its contents are dumped in a section of the bay used for billet storage On either side of the 22-in. mill is a pair of travel- ts Rolled on the First Stand of the 22-In. Mill Are Delivered Directly to an Up-cut Hydraulic Shear with Motor- Driven Gage for Cutting Lengths Desired ing electrically-operated tilting tables, each equipped with three Westinghouse motors of 30, 60 and 80 hp. respectively. Opposite the second stand on the furnace side of the mill is a roller table equipped with an hydraulically-operated up-cut shear. Pull-overs, one on each side of the mill, carry the finished material to a delivery roller table, whence they are conveyed to a motor-driven hot saw and then to a hot bed. All chan- nels, angles and beams are passed through a series of four two-high straightening rolls after leaving the hot bed. The straightener, which rests on shoes and is pulled into or out of alinement with the roller table at the end of the hot bed by means of a cable operated by overhead traveling crane, was constructed by the United Engineering & Foundry Co. It is equipped to take channels and beams, 4 to 8 in. wide, and angles up to 6 in. After finished material is straightened, it passes to transfer tables and thence to one of two motor-driven oe nee » eet ies je Charged into the Reheating (onveyor to the Receiving End, Where Pushers vertical United Engineering shears, by which it is cut to length. It is then dropped by motor-driven kickoffs to cradles and inspected. All bars are straightened in gag presses or roller straighteners if required. After inspection the product is transferred by overhead crane to a Fairbanks 20-ton scale, and is made ready for ship- ment. Inside the building and adjacent to the scale, is a shipping track with a capacity of five cars, facili- tating the loading of material direct to freight cars. Space in the open bay between the 22-in. mill build- ing and the merchant mill is utilized for roll and billet storage. The billets—ordinarily 3 x 3 in. or 4 x 4 in— after weighing on a Fairbanks 5-ton scale, are con- veyed by overhead traveling crane to a chain roller- type belt conveyor operated by a 20-hp. Westinghouse motor, which carries them to the receiving end of the continuous reheating furnace serving the 12-in. mer- chant mill. By adjusting stops on the conveyor the billets are brought to position at desired points oppo- site the end of the furnace, so that three rows, two row of billets may be run through the rows or one After Shearing, in Open Bay Between the Buildings THE IRON Furnace Serving the 12-In Operated Billets Are Kicked Off Down the Skid Chute at Right to Billet Conveyor Which Carries Them 2 | Hot bed is beyond conveyor; delivery roller table and hot saw at le AGE March 31, 1921 Merchant Mill Are Carried by a Chain Roller-Ty) by Rack and Pinion from a 30-Hp. Motor Charge T} furnace, as the billet length may dictate. Pushers operated by rack and pinion from a 30-hp. Westing house motor charge the billets into the furnace, at the same time forcing out billets at the delivery end. The reheating furnace, heated by four oil burners, is sim ilar in design to the furnace serving the 22-in. mil having a hearth 10 ft. wide and 38 ft. long. The fm nace was constructed in its entirety by the Scullin con pany. A single stack serves both of the reheating furnaces, 5 The merchant mill building contains a three-high 16-in. roughing mill and a 12-in. merchant mill con sisting of one two-high and four three-high stands Later the 16-in. roughing mill will be supplemented with a finishing stand. The 16-in. mill is driven through a gear set by a 600-hp. Westinghouse constant speed induction motor of heavy steel mill type, taking three- phase 25-cycle current at 2200 volts. The motor speed of 487 r.p.m. is reduced by gears to a mill speed of 87.4 r.p.m., the rolling speed being 366 ft. per min. The motor is connected with the mill by a flexible larch 31, 1921 ng on the Three-High 16-In. Roughing Mill. At right the 12-in. mill “lywheel and gear R ipling and herringbone gear unit with two fly wheels the pinion shaft, 6% ft. in diameter and weighing 1000 Ib. each. From the 16-in. rougher, material sses through an electrically operated shear and to pony roughing stand of the 12-in. mill. » A New Type of Adjustable Speed Drive The drive of the 12-in. mill is the first of its kind be installed. Heretofore adjustable speed a.c. motor sets have been either of the Scherbius or Kraemer type. Both have certain disadvantages which, it is believed, have been successfully overcome in the new Westing- house set at the Scullin plant. The principal criticism of the Scherbius type set is that the torque is constant at all speeds, although heavier material rolled at s owe} speed calls for a greater torque than light material rolled at higher speed. The Kraemer set is of two types, one of which operates at constant torque and the other at constant horse power. With the latter type, the objection to the Scherbius type set is over- ‘ome, but the Kraemer type sets present certain diffi- ilties in speed adjustment. There are really two the Two Mill Buildings Is an Open Bay Used for Roll and Billet Storage. The false roof serving as cooli tank for water is in the valley between mill roof at left and furnace charging building at far end THE IRON AGE 833 is the electric shear preceding the pony roughing stand of casing are at left, beyond foot-bridge separate speed ranges, one above and the other below synchronism, but the transition from one to the other cannot be made under load. The motor may also be operated as a constant speed machine practically at synchronism, but to change from that speed to either of the upper or lower speed ranges, the motor must be stopped. The new Westinghouse installation at the Sculli plant was designed to permit the adjustment of speed, without interruption and without removal of load, throughout a range extending from below and through synchronism to a point above. At the same time, the torque varies inversely with the speed. The set in- cludes an 800-hp., 2200-volt, three-phase, 25-cycle heavy steel mill type induction motor, a synchronous moto: on the same shaft, and a frequency changing unit. The induction motor is started with an auto-controller set at close to synchronous speed, 187% r.p.m. The syn chronous machine operating on the same shaft is just floating on the line, having no current passing through its fields. If the speed of the induction motor is in creased up to the maximum, 225 r.p.m., or decreased ng tes: ee apy ore ; f ; : ' rt Shee agente el ett «atin In aa Ss a all i Bee a 8! AR a eS ee a 7 r 1 t a >>. eI ut Re e #4 til ae i THE IRON AGE March 31, 192 t 1 1 naot Manipulator Jable Sarvtarn on || Toke I r I t t Pump Pit Stack ' ' ' 0 0 40 o o « @ ,? 4 i / ay J ' S ih < e rf wo y Zand /6"MILLs zavout o§f the Mills, Showing and to the Shipping Rolling Mills ug the to the minimum, 150 r.p.m., a 10-hp. motor connected by shaft with the frequency changer must be started. As the driving mill motor is slackened in speed, its loss in horse power is made up by the synchronous machine operating on the same shaft, so that when the speed is decreased to the minimum, a decrease of 20 per cent, the corresponding loss by the induction motor of 160 hp. is made up by the sychronous motor. On the other hand, when the induction motor is running at a speed above synchronism, the synchronous machine operates as a generator. The driving mill motor is a standard induction ma- chine with six-phase secondary winding, and the other unit on the same shaft is a standard synchronous ma- chine wound for the same speed and frequency as the main unit. The synchronous machine, as previously indicated, operates as a motor at speeds below syn. chronism and as a generator at speeds above synchron- ism. The auxiliary frequency changing unit com- prises a small synchronous motor connected to the fre- quency changer, which is a special apparatus similar The a.c. end of stator of the syn- shaft, while the other end is connected with the slip rings of the in- duction motor. in appearance to a rotary converter. connected with the the changer is cl motor on the main 1ronous motor Speed adjustment is obtained by intro- ducing a counter voltage in the winding of the rotor of the main motor through the changer. When operating below synchronism the slip energy of the main motor through the chronous motor. passes frequency changer into the syn- When operating above synchronism, the synchronous machine is driven as a generator and transmits energy the changer to the Speed through rotor of the _ induction motor. adjustment is obtained by moving a field rheostat controlling the field of the rotor of the synchronous machine. The driving mill motor is con- nected direct to the mill through a flexible coupling and a 9-ft., 19,500-lb. fly wheel, mounted on its own bear- The motor speed range of 150 to 225 ings. r.p.m. is accompanied by a rolling speed range of 470 to 700 ft. per min. Complete control of the 12-in. mill drive is concen- trated at one point. A magnetic controller is operated master switch which has been is most convenient for the operator. mounted where it The speed adjust- mounted near the The the 22-in. mill mag- netic controllers operated by master switches arranged for floor mounting. The flexibility of the 12-in. mill from a production standpoint has been materially enhanced the wide speed range at constant horse power. DY a ing rheostat is switch. 16-in. mill master and motors also have because of Small sections may be rolled at greater speed than heavier material, and thus the tonnage output of the mill main- Travel of Department at the Left Progressive Material from the Heating Furnaces at the The rolls are shown solid black mill ha On one day in December th output was 110 tons in ten hours, and for several hours during that period, over 12 tons an hour. On another day 957 billets passed through the mill in 540 min an average of nearly two a minute. The highest hour); rate was 167 billets and the total output for the period was 70 tons. thus far achieved on the been highly sati:factory. tained. Records From the finishing stand of the 12-in. mill, mat roller table to a flat hot bed, which was constructed by the United Engineering & Foundry Co. Shuffle and rachet movements progress the product across the bed to roller table, by which it is carried to a United Engineering vertical motor-driven shear and cut to length. Straightening rolls have been provided for straightening small angles and channels and other irregular shapes, while a gag press is used for straightening rounds, flats, squares, hexagons, etc. rial is passed by bar This Adjustable Speed Drive Is the First of Its Kind t Be Installed At right is the rheosta® and at left the frequency changing unit Material is weighed on a 20-ton Fairbanks scale before being loaded into switched into the building. cars which are The rolls in the stranding and finishing stands the 12-in. mill are of east iron, but the rolls in roughing stand of the 12-in. Mill and in the 16-in. and 22-in. mills are of steel, cast in the Scullin company * own foundry. Although roll making represents a new undertaking for the steel castings department of the plant, excellent results have been obtained with the rolls cast for use in the new mills. The fact that ™ roll breakage has been encountered with these ro!'s commands attention, as it is unusual for a mill to st up with a green crew and escape difficulties og tna character. From a tonnage standpoint the perform: ance of the rolls has been exceptionally good, wher considered in the light that no dressing has proves necessary. To take care of its own future needs, “ tne well as to supply outside demand, the Scullin company March 31, 192} llent Light Is Supplied the Catchers of the 12-In. Mer Monitors in the Roof. There are one ts to set aside a part of its foundry for roll cing. or machining rolls a shop has been provided which oins the shipping end of the 12-in. mill building and jects into the open bay between the two mill struc- \ narrow gage track down the center of the roll is connected by turn-table with a track which runs the merchant mill building. As an auxiliary to e trucks which operate on this track. a five-ton Cur- Pneumatic Machinery Co. overhead traveling hand- power crane has been provided. The shop is excep- mally well lighted, both by side sash and overhead nonitors. The feature of the shop is the heavy roll athe equipment, furnished by the United Engineering & Foundry Co., which includes an 18-in., a 26-in. and 1-in. machine, all with double beds, each being equiv- ilent to two ordinary lathes. At least two rolls may e machined simultaneously on each lathe, and often is many as three and four rolls at a time, depending n the size of the rolls. The roll lathes are operated Westinghouse motors. Other tools in the shop in- rolls may be machined simultaneously THE IRON AGE 835 hent Mill by Continuou Sasl n the Wall is Well as two-high and four three-high stand clude a Lodge & Shipley 18-in. x 10-ft. geared-in-head lathe, a Gould & Eberhardt 24-in Baker Brothers heavy duty drill, an Atkins power hack engine shaper, a saw and a United States Grinder Co. double tool grin der with 3% x 24-in. wheels. All of these latter ma chine tools are operated by General Electric Co. motors Valley in Roof Used for Cooling Tank The water circulation system which cools the rolls in the mills and the furnace skid pipes presents some Water is pump from a cold well with a cen- novel features. drawn by a Dayton-Dowd 2000-gal. per min trifugal pump head, located under the ingot feed table platform at the charging end of the 22-in. mill reheat- From the cold well it is driven through a 10-in. main to the mills and furnace skid pipes, ing furnace whence it drains back to a hot well located near the motor house. From here it is pumped by a_ second Dayton-Dowd Co: 2000-gal. per min. pump, operated by a 75-hp. General Electric motor, to cooling sprays situated in the valley of the roofs connecting the 22-in- kest of the Three Heavy Double-Bed Lathes in the Roll Shop Is the One Shown—a 34-In. Machine. Two or more on each lathe, depending on their size pees ; : : a ee eer mere a ’ i eea pcan oF: nl tee &36 mill building with the furnace charging building. Here a 150-ft., false wood-sheathed roof, covered with “Cer- tainteed” roofing to make it waterproof, serves as a receptacle for the water discharged by the sprays. The utilization of the roof as a cooling tank was decided upon because it serves the purpose just as satisfactorily as a concrete well and was considerably cheaper to ‘construct. The spray header has about ten branches with approximately sixty cooling sprays. From the spray roof the water passes by gravity to the cold well, First Aid Station, with Perma ent Attendant, Is Completely with Operating Table Needed (Right) Equipped nd Other Appliances \ Model in Insulation of Equip nent, the Sub-station Has a 500 Kw. Rotary Converter for 230 Volts it Right Back of it is a 550-kva é ransforme! Behind the or t right end of switch oard are the main oil switches for (Above) le nes ifter which it is used again. The spray system was furnished by the Cooling Tower Co., New York. The high-pressure hydraulic system operating up- it shears, the blooming stand roll balance, the ingot nanipulator, etc., is composed of two 300-gal. per min. Aldrich triplex vertical pumps, operating at 550 lb. per These driven by two 150-hp. General Electric Co. motors. A 17-in. Aldrich fixed cylinder-type accumulator, hooxed into the line, sq. in. pressure. pumps are mechanically operates an unloading device control for the pumps, in addition to electrical safeties. Concrete allast weights are used to build up pressure. Oil for use in the steel mills is drawn from a 1,000,- 00 gal. oil storage located at the older Scullin plant, to a THE IRON AGE March 31, 192) 20,000-gal. underground storage tank near the 22-in. mill building. The tank is of concrete treated with various densifiers to make it impervious to oil. Pump- ing equipment includes two Goulds twinplex pumps, which maintain a pressure of 100 lb. per sq. in. Niagara meters indicate the oil consumption of each reheating furnace. 7 The power sub-station serving the steel mills is a model from the standpoint of construction and equip- brick ment. It is built of reinforced concrete and Six Hundred Lockers, Together with Shower Baths, Lavatories and Other Toilet Facilities, Are Provided for the Men (Below) Cur- throughout and all apparatus is well insulated. rent of three phase, 25 cycle, 13,200 volts, is bought from the Union Electric Light & Power Co., St. Louis, and is transformed to 2200 volts for mill drives and 220 volts for mill auxiliaries. Equipment in the station includes a Westinghouse three-phase 550-kva. trans three single-bank 1000-kva, transformers high tension loads, three 100-kva. transformers 220-volt alternating current mill Westinghouse 500-kw. rotary converter for direct current. There are 16 panels in the switchboard, all furnish by the General Electric Co. All of the oil swite The board is also equipped wit" Y former, auxiliaries and 230-Vi are solenoid operated. March 31, 1921 iphic watt meters which indicate the power consump- n of the mill motors at all times. All wiring and itches are inclosed in concrete and the foundation is neycombed with tunnels, which make it possible to g in a line or take one out without tearing out any the walls. Space has been provided for the installa- of another rotary converter when the need for it ses. Arrangements also have been made so that wer can be thrown in from the foundry unit of the scullin plant if necessary. [he company has provided up-to-date facilities for comfort and convenience of its employees. In the flice building a first aid room has been fitted up where en may be given initial treatment after injuries. A ermanent attendant is on duty in this room at all mes. If serious cases should arise, the company has ; own ambulance to transport the injured to its hos- ‘ital at the older plant. The building containing the offices also houses the washrooms and lockers for the men. There are 600 lockers furnished by the Fred Medart Mfg. Co., St. Louis, with three double shower baths, four large vatories and other toilet facilities on each floor. The ntire building, of reinforced concrete and brick, em- odies every precaution to insure cleanliness and add the comfort of employees. A sanitary station of onerete and brick is located in the open bay between he two mill buildings, a most convenient point from the standpoint of the mill hands. All plumbing was furnished by the J. Sheehan Plumbing Co., St. Louis. The motor houses, the roll shop, the sub-station, the BUYERS IN CONTROL Conditions in Canadian Markets Resemble Those in the United States forRONTO, March 28.—The buyer is still in control of the iron, steel and machine tool markets at all points in Canada, and in a good many cases he has taken ad- antage of the fact to batter down schedules to a point where he feels it is to his interest to come along and lace his business. Canadian manufacturers are releasing a fair ton- nage that had been held up on suspended shipping or- lers from the American mills. But many of them are irawing from the warehousing interests entirely. The warehouses for weeks past have been buying very little n fact, the word buying is not the right one to use, as has been a case of releasing shipments. The steel merchants have been busy liquidating their stocks, nany of them still having a tonnage taken from the remium mills when prices were all in favor of the It has now turned out that some of the lines getting low, with the result that yards having n are able to sell now at their regular prices, mak- i profit instead of simply turning that much stock ‘ash. Of course, this refers to only a few lines, it it is an interesting development, and shows the Ww margin on which some of the merchants are ng on business at the moment. mill material is moving slowly. Canadian for some time were asking 3.75c., but are lower that figure now. Warehouses for a long time held rr 4.50c. and that is the present warehouse figure jut it is nominal, and lower than that is being | right along. Tubes Moving Slowly ilar goods are moving slowly, and the size of siness that has come in from lake fleets has been ointingly small, The small tubes, principally ire moving out now, as many contracting firms ‘ting their field equipment in shape for the sea- vork. Competition from Buffalo warehouses is this district, and even more so in the Niagara where the power development work is being on under Government assistance. That busi- { ERR te A ENS NIM he DIL ee wT THE IRON AGE 837 office building and the comfort station are heated by a hot blast indirect system using steam pipes from the main power house in the older unit of the Scullin works. Air required in the mills is also supplied from that source. There are six overhead traveling cranes in the plant, of Whiting, Alliance and Scullin design. In the mer- chant mill building are two 10-ton cranes and in the storage yard two five-ton cranes. The large mill build- ing is equipped with a 15-ton and a 50-ton crane. The large mill building is 76 x 487% ft. and is ad- joined by a motor house, 35 x 60 ft. The merchant mill structure is 75 x 500 ft., and adjacent to it are a motor house, 20 x 80 ft., the roll shop, 35 x 100 ft., and a carpenter shop, 12 x 80 ft. The office and service build- ing is 50 x 82 ft., and the sub-station, 52 x 54 ft. The buildings were erected and the machinery foundations constructed by the Fruin-Colnon Construction Co., St. Louis. All machinery and equipment, including elec- trical and pipe work, were installed by the Scullin or- ganization. Perin & Marshall, New York, were consulting engi- neers on the construction and equipment of the mills, co-operating with the management of the Scullin com- pany. Active on behalf of the company were F. B Menner, manager mill department, George H. Raab, mill superintendent, William J. Davis, electrical super- intendent, and John Johnson in charge of brick work. H. W. Eales, chief electrical, engineer, Union Electric Light & Power Co., St. Louis, assisted in the design of the power station. ness_is highly desirable on account of the ready pay, and very little business gets by now without pretty keen competition. Sheets have been in demand recently by interests connected with the pulp and paper indus- try, and some of the mining concerns in the north country have also been purchasing supplies. The automobile shops are getting under way again, the best of them doing about 50 per cent now. They are not buying heavily yet, but have released some con- tracts with outside shops for parts that were held up some months ago. Railroads Not Buying Freely The railroads are not buying heavily. The past winter has been an easy one for this country, snow storms and blockades being almost unknown. The re- sult has been an easy season on equipment, both on the roads and in the shops. The National Railways, show- ing a deficit of over $100,000,000 for the past year, are not buying freely. There are a large number of legitimate inquiries being made, and these are coming from a very wide range of industries. Representatives of British ma- chine tool firms in this country report that they look for decreases in the prices of machine tools from their firms in the very near future. Some of the makers in England have very large reserve stocks piled up, and it is necessary for them to move some of these out. Small tools are being bought sparingly, and prices are cut pretty close in order to get the business that is passing. Some of the dealers state that they know of jobbers doing business on a 5 per cent profit. Little on the Books The steel mills in Canada have little business on their books. They had expected that the railroads would keep their rail mills busy, but this has not turned out according to expectations. Scotia furnaces are pretty much all banked in the East, and they are getting their billets now from the Dominion Corpora- tion, which is running on a much reduced schedule. The Ontario plants are faring a little better, but their orders are getting pretty thin. One stack is starting to pile pig iron, believing that the demand will be stronger a little later on. The price quoted is still around $39, but reports are current of sales being made fairly well under that figure. ‘eb & + 7 j f 7 ‘ : »)O Sod Pneumatic Hammer for Breaking Pigs The accompanying illustration shows the pneumatic which the Sloss-Sheffield Steel & Iron Co., Birmingham, is manufacturing for breaking pigs and sows. In THE IRON AGE of Feb. 17 the hammer was The following additional information has been obtained from J. P. Dovel, superintendent of blast furnaces for the company: The equipment consists essentially of a strong pneu- hammer with valves and ports so arranged and the hammer and piston of such a size that a blow nammer de scribed. math may be struck of sufficient force to break a pig into halves and sever it from the sow at the one stroke. It is used also for breaking the sows into pieces of desired length. cylinder is 8 in. As noted in the article mentioned, the in diameter and the stroke 14 in. The Pneumatic into the Broken by the have been arranged so that no damage will result the hammer misses its object and strikes its full force into the atmosphere. The hammer is suspended flexibly from an electric traveling crane. The bed of pigs is placed on a heavy cast iron frame, which in turn is mounted on a plat- form above open-top railroad cars. When the pigs are broken they fall through the openings in the frame directly into the cars. The hammer is carried over the pigs by means of a crane and is operated by a hand lever valve at a speed of about 15 strokes per minute, making an average of about one ton of pig iron per minute. Five men are required for the work, which covers all the operations from the casting beds to the railroad cars. The equipment has been used for two years and it is regarded as an unqualified success and a money-saver. ports in case Disposing of Steel Plates at Seattle SEATTLE, March The feature of the week in the steel trade was the general cleaning up of desirable sizes of plates held in the dismantled shipyard stocks, and which have been a deterrent factor in getting the jobbing trade on a healthy basis. It is the opinion of wholesalers that there are not enough of these plates now left to affect the regular demand. Sheet stocks are heavy, and there is reported to be an inclination 26.- THE IRON Hammer They Railroad Cars AGE March 31, 19 on the part of the mills to take losses on old « ) The jobbing trade here can get price concessions outside mills on desirable orders. . A few specia of plates are selling for the account of the shi: at Tacoma, but there is no great volume of t) . First shipments of structural steel for th bridge over Hurricane Gulch, in Alaska, on th under construction by the Alaska mission, have left Gary for this loaded here for Anchorage, Alaska. The ton) this job is 1500. The main arch is to be 384 The height from the center of the gulch will be The first lot to arrive will be 500 tons. At th time 50,000 tie plates will be shipped. The co sion is operating three caterpillar tractors and pillar trailers beyond the end ef the steel in hay supplies to the construction camps, this being the ade Fe RR Engineering port and w Fall Through the Openings of the Cast-Iron An use of caterpillar machinery in Alaska. The stean ship LaTouche, which has just sailed from this po for Alaska, had three large boilers for delivery to commission in the North. The boilers came out of junked shipyard holdover. The suit brought against the United ping Board asking $3,220,000 damages for the seizu of the Sloan shipyards in December, 1917, was missed in the Federal court at Seattle, which rut that the board was a Government corporation a subject to suit. State Sh “If one should roll off——?” is the captio! photograph in poster form being distributed National Safety Council, Chicago. The captio! tinues: “Ingot molds should not project beyond of car. Stand ’em up straight.” The photograp! picts two parallel trains of cars loaded with ing molds, on one the molds being upright and other, horizontal and projecting over the car edgt The Western Purchasing Co., Mills Building, 2aso, Texas, has an inquiry from one of its Mex clients for 20 55,000-gal., 10 11,000-gal and two - gal. steel tanks, to be delivered at any Atlantic or ° seaport. A large quantity of line pipe and well « is also needed. ) i) 4 industrial Application of Powdered Fuel’ Method of Transfer of Heat Energy—Temperature Cycles Involved — Design of Combustion Chambers oper —Some Processes Peculiarly Suited to Powdered Fuel 7 BY JOSEPH F. SHADGEN oN verized solid fuels are developing every day, an independent analysis of the future possibilities ms very timely, not only to survey the progress made S the applications of the combustion of finely pul- A \ ing the last decade, but also to discount over- thusiastic statements. Special emphasis must be on the point that pulverization of solid fuels is from being a cure-all of all combustion troubles; ne grinding permits merely a method of burning coal ficiently, and experience has shown numerous fields applications where the practical conditions are most vorable for good economic results. \ll uses of heating and combustion problems are governed by the phenomena of heat absorption, as the ilories released by the chemical oxidation of the fuels have to be efficiently transmitted for the industrial pur- pose in view. Efficient generation of the heat units useless unless their absorption is controlled with skill, without waste, to guarantee maximum overall efficiency. Importance and Complexity of Study it follows that the prablem of heat absorption is second to none in its immediate bearing on practical results; this fundamental truth should be realized by all users. To burn the coal correctly is only the first halv of the combustion problem, as all the calories that are not absorbed by the material to be heated are sim- ply wasted, no matter how efficient the generation may ind regardless of all refinements in burners. The logic is obvious, but nevertheless it needs emphasis be- ause it is forgotten every day and is often pushed in the background. Heat is transmitted from one material to another three ways: by radiation, by convection and by con- ction; and the study of these three phenomena, com- ed with the physical changes and chemical reactions iived in each industrial application, form the basis the solution. The complexity of the problem con- ists sharply with the relative simplicity of laws and rs controlling the generation’ of heat by combus- nm of the carbon and the hydrogen of any fuel. The nglement and coexistence of the different phe- na, the varying relative importance of each, de- ling on ever-changing conditions, the invisibility of medium of heat, making losses difficult to locate waste hard to avoid, are only some of the reasons the problem is so difficult to solve correctly, and onstant attention and permanent efforts are re- d to maintain efficiency. The complexity of the em does not permit in a short investigation of ature a thorough analysis of all phases; therefore, the main features and the recent progress will be sed in a summarized way. A great deal of ex- nce gained in the last years of rapid development obvious reasons, not yet available for publica- nd this applies in particular to powdered fuels. eral our knowledge on the subject is most chaotic. reflected by the thousand and one practical and rr less equivalent solutions of the same problem. ¢ iler field illustrates best this statement. Backed ’ ght, 1921, by Joseph F. Shadgen, consulting engi- York The author discussed “The Status of the Fuel Problem” in THe IRON AGE of Jan. 1, 1920 r of Pulverizing Coal,” issue of Feb. 5; “Pulverized tributing Systems.” issue of May 20, and “Science ed Fuel Combustion,” issue of Aug. 19. by nearly a century of experience and world-wide de- velopment, favored by thousands of theoretical investi- gations and scientific researches, the laws of nature involved in the steam boilers are not yet uniformly interpreted, as the numerous systems that dispute the favor of the buying public prove. Parenthetically, it may be opportune, at this place, to point out that the greatest handicap of all heat problems is our inability to measure the energy directly. This impossibility of determining by direct reading of instruments the efficiency as well as the losses of any heat cycle, be it a furnace, boiler or steam motor, neces- sitates complicated tests that usually lack the wanted accuracy, and the data secured always require inter- pretations that often lead to controversy. That unfortunate condition, the main reason of the confusion in the art of all heat appliances, is the cause of the lack of reliable foundations for designers and builders as well as operators. In recent years, with the help of electricity and recording instruments of all kinds (temperature, COs and flow gas indica- tors), great strides toward more accurate knowledge have been made, but considerable progress remains the task of the future. Heat Radiation The transmission of heat by radiation is usually explained by the theory of transverse vibrations of the hypothetical medium called ether. It is presumed that heat radiation produces a rectilinear periodic disturb- ance of the ether, and that the phenomena are inde- pendent in every way of the presence of matter between the emanating and absorbent body. The velocity of propagation of these waves is the same as the velocity of the light. It is explained also that light and heat > waves differ only by the pitch and frequency of their vibrations. Radiant heat is transmitted in the vacuum just as much as in atmospheric conditions and follows always the straight line. The most important factors are the temperature and the nature of the surfaces. The law of Stefan-Boltzman, which is accepted as practically accurate, indicates that the amount of heat radiated by any body is proportionate to the fourth power of its absolute temperature. This shows the enormous influence of the flame temperature and its effect on the efficiency of heat transmission. The nature of the emanating and receptive surfaces is the second factor of importance. Most of the text book and refer- ence volumes relate experimental figures applying to dark surfaces:(lamp black), but no real information for practical conditions can be found. As most of the industrial furnaces are built of refractory material that becomes white hot in the combustion chambers, those figures have to be discounted considerably. A scientific investigation duplicating practical conditions would certainly mean a great step forward, and unify many divergent opinions. : The absorption of heat energy by radiation is of great importance when burning solid fuels in finely pulverized form, because, first, as explained in a pre- vious chapter, the highest flame temperatures can be obtained by the easiest means without preheating the air; second, the uncombined carbon gives a high radi- ating flame, and, third, the ash particles that soil the combustible matter become small incandescent floating 839 " ; 4 Be Pb Me ts omapiset eee 840 masses that are carried in the stream of waste gases. This highly radiant ash dust increases the radiant active area, which in some fields is reflected by higher efficiencies. Designers should take advantage of this fact and develop constructions that take care of this peculiarity. It that the ash problem has its redeeining feature that counterbalances partly the dis- agreeable and complicating deposits in the flues. seems Heat Conduction The transmission of heat by conduction is the slow process of permeating gradually any solid material, layer by layer, by increasing the temperature of all intermediate strata until equilibrium is attained. This process can be easily visualized by sticking one end ot a bar into a forge fire, and all its laws are familiar to every high school student in the elementary course of physics. The heat has to overcome, by contact, the natural resistance of the material to any change of its equilibrium, and this is explained that any change in the vibrating produces a resetting of molecular according to a temperature structures certain motion. This resistance as characteristic to each body is called specific heat, and values for each metal or materia! are found in all hand or text books dealing with the subject. Two features of the conduction phenomena are most important in the practical applications. First, the transfer of heat varies considerably with the tempera- tures, and there are real specific heat factors and mean or average specific heat factors between temperature limits. This has to be taken into consideration in figur- ing out data, and remarkable confusion exists because the results of the various experimenters are mixed. The author intends to deal with this subject in a special chapter. Second, the transmission of heat by contact is linked to the factor time; it is impossible to hurry this method of propagating heat energy, and that is why the practical saying, “Let it soak in the furnace.” has a theoretical reason. Reheating a big bloom, annealing a heavy casting or equalizing the temperature of an ingot in a pit furnace are operations familiar to all steel men, where the time factor is of the greatest importance, where hurry is least recom- mendable, for an even temperature within the material Consequently it is unwise to push these op- often is wanted. erations, and that is why furnace capacity has to be carefully determined beforehand. Conduction of heat is independent of the fuel used to generate the heat, and therefore the method of burn- ing solid fuels in finely pulverized form does not intro- duce a new feature in that phase of the problem. Heat Convection Fluid bodies, besides the phenomena of conduction, transmit heat in a third way called convection, which means that the heat energy is carried from place to place and propagated by ‘the currents of the medium itself: this method is characteristic to liquid fluid ma- terial, such as water and oils, and to gaseous fluid bodies like air, carbonic acid, or the products of com- bustion, a mixture of CO., water vapors and N,. The great mobility of the molecules inside of any fluid mass causes-these phenomena, as it makes changes of the relative position, currents and eddies very easy and subjects those materials to movements due to changes in densities subsequent to variations in temperature. As explained in the previous chapter of these studies dealing with the generation of heat (THE IRON AGe, Aug. 19, 1920), in every furnace where fuels are burned the gaseous products of the combustion become the carrying medium of the heat energy liberated by the chemical reactions involved. The production of these gases is continuous and the function of this flow of hot gases is to give up the heat efficiently while trav- eling through the furnace. To reach that aim the ab- THE IRON AGE March 31, 192 sorbing body must be swept by a maximum amour hot gases; in other words, the material must be «, pletely submerged in the currents of the heat-gi\ medium. Complete submergence is very important the convection phenomena are dependent on the a) of contact. If parts of the body to be heated are « side of the currents, the results will be lessened in portion. The résistance of any solid to the penetration of ¢ heat from the outside is expressed by a factor cal), thermal conductivity, and their values for each bou have been determined experimentally per area per tin unit. For metals this factor is high and for insulat i very low. ) i , Further studies of transmission of heat by conv: tion have led the experimenter to suppose that on ea surface to be heated by a fluid current, a tiny film e) ists that creates an additional resistance to the prop: gation of heat. This film varies with the nature of th. fluid medium, and its influence depends mostly on th: characteristics of the motion of the fluid. That hot a; creates a different film from hot water or oil can easi): be conceived, and that great violence in the currents duces the thickness of that imaginary film and ofte: tears it or at least diminishes its resistance to hea‘ transmission seems logical to imagine and is confirme by all technical experiments. Burning pulverized fuels does not bring any new factor into the convection problem except through th presence of the ash particles floating in the hot gas currents. This dust may deposit in the flues or on th: material to be heated, and thus create additional ré sistance by acting as an insulator. The presence of th ash is also annoying in so far as it affects the life ot the brick work and sometimes reduces the area of th« flues, thus causing shutdown for cleaning or repairs Research Possibilities The above considerations amply prove the impor tance of the flow of gases in any furnace, its influenc: on the efficiency of the heat transmission and its prac tical value for the designer. The study of this flow of hot gases inside of the furnace walls has comfortabl) been completely neglected, and very little attention ha been paid to its obvious practical value. The first at tempt to put the problem on a scientific basis is the r markable investigations of the esteemed Russian pr fessor, W. E. Groume-Grimailo, of which fragments were presented to the English speaking public last year. Mr. Groume-Grimailo’s efforts resulted in a new % theory called the application of the law of hydrauli ’ to design of furnaces, which presents enormous oppo! tunities and opens new aspects to this complicate: problem. Several examples of details that are unknow in the ar