Document ZJ65YjzbXdG9005OeK8DLrKmO

DESTE FIDELES"______ Come all ye faithful. Once again the singing of carols, the hurrying crowds, and an air of happy anticipation herald the Christmas Season. In this spirit, all of us at Elliott Company extend holiday greetings and test wishes for the New Year to you, the readers of Powerfax. WINTER, 1955 Volume 33 No. 4 Front Cover Our front covers this year have featured '. K' 'photographs of power and industrial ne? - For this winter issue, we pres ' * * . sional Christmas scene especially drawn Jon = ?-: Power]ax by the talented Pittsburgh artist Tom Miller. It is portrayed in the feel^ ing or style of the three previous covers^ plus, of course, the true Christmas spirit;' We hope you like the picture which, you will I'j note, carries over to our sincere greeting^- opposite. f *7District Offices , Elliott Company's office in Charlotte^ North Carolina, was recently moved fro -'>1916 to 1707 Liberty Life Building. The' . " 'v telephone remains the same: Edison 3-9172>%> The district manager remains W. J. L . Large Mill Motor Standards ^_ .At the .Association of Iron and Sfeefg % Engineers'' meeting, held in the Hotels Sherman, Chicago, the latter part r, C. R. Steen, chief dc engineCT^ ^Crocker-Wheeler Division, Elliott Com*^ 5Fpaay, discussed a paper by M. B. Antrim, of"* iLnkcns Steel Company, who is chairman of -the mill motor committee. The subject waffg - the AISE proposed standards for three higher-capacity mill motors--275 hp, 3755 gRr hp, and 500 hp. These new larger sizesja mill motors will use fabricated, instead 'efefccast, frames and they will be for coupledJ-j ^drives only. Crocker-Wheeler made the " ** l motor in 1904. CONTENTS AROUND ATI-ANTIC C(TY ELECTRIC COMPANY'S DEEPWaTER AND GREENWICH STATIONS ARKANSAS POWER AND L1CHT KEEPS AHEAD OF DEMAND FREEZINC BREAD TO KF.EP IT FRESH (Arnold Baker*) SKATf.VG EVERY WINTER DAY /.V NEW ENGLAND TEWS CITY REFINING'S HOUDRIFI.OW UNIT THE SAGA OF THE "WANDERER" NEOPRENF. LINING OVERCOMES SALT WATER CORROSION CONDENSER IN A PETROCHEMICAL PLANT IN THE CROMBY STATION OF PHILADELPHIA ELECTRIC COMPANY ELLIOTT MOTORS POWER NEW HYDRAULIC FORGING PRESS (Locuy Hydropre** Inc.) SHALLOW WATER DREDGE (Tuner DreJi{in< Co.. Inc.) A PILOT EXCITER WITHOUT A COMMUTATOR COAL BARCE UNLOADERS USE ADJUSTABLE-VOLTAGE SYSTEM `Ohio Valley Electric Corporation) 3! POWERCJtAX Potvrrjax, published by EUioit Company since 1923, is primarily a record of the development of Elliott products and their application in industry. Over 35.WQ copies are distributed quarterly to Eiiion cus tomers and friends. Address correspondence to C W. Kalbfus, Editor, Elliott Company, Jeannette, Pa. To schedule a showing in your plant, or to arrange to borrow the film for use in your training program, get in touch with vour Elliott representative. Ask for the movie describing the "INSTALLATION, OPERATION, AND CARE OF YOUR ELLIOTT MECHANICAL-DRIVE TURBINES." Copies of a leaflet describ ing the contents of the film (Bulletin H-24) are also available. Movie Seems lo be a Hit (Earlier this year, we announcedTu *Tatt*rJax the release of a new 26-mm s eon-film moving picture. The film describes in detail the prope ij procedure for the maintenance and repa f Elliott mechanical-drive turbines. It up ghtforward technical presentation nw^Ies pitch or product plugs. Itsi :>*to be helpful. _ tody the movie serves its pu ^brokings have been heavy and * several additional prmts I* l>cn shov% turbine operators, mainU '"atrainees in this country, in C Elliott mech Big Boring Mill Gets Sure Footing The installation of a 30-ft boring mill is quite a project. Such a machine was recently put into service in ourJeannette shops. One photograph shows the labyrinthine founda tion which was prepared. This measures 40 ft by 40 ft, and is 13 ft, 6 in. deep. It required 32 tons of reinforcing rods and 210 yards of concrete. The new mill has a 16-ft clearance under the crossrail, and is equipped with two 9-ft travel rams and a 19-ft, 6-in. table- Special features such as electronic feed control, electrically operated set-up clamps, individual ram counter weights and ram-swing saddles will enable Elliott engineers to fit the mill with profil ing equipment. The picture of the finished mill also includes, at the left, a 20-ft boring mill, which has been in service for many years. Shown on the new mill is a generator stator frame for a large hydro job. - The Greenwich station, at Gibbstown, houses a lQ,OOQ-kw noncondensing unit. Around Atlantic City Electric Company's Deepwater and Greenwich Stations Southern New Jersey entertains many thousands of visitors along its excellent beaches each summer. This territory is also known for its farms (New Jersey is j \ often referred to as the Carden State) and is growing industrially. The chemical ! ** industry, particularly, is showing large expansion. * , The Atlantic City Electric Company furnishes electric service in a 2700-sq mi Deepwater station. near P (.rave, on the Delaware R, Inn a co/ienilr nj J13,500 Hi5,000 kw of which is Jinsing, hnlanee hying .applied tiy baek-peessine area in southern New Jersey that comprises almost one-third of the state. It serves turbines. . over 300 communities, a population of 492,000, and its list of customers currently totals 200,250. Its generating capacity of 318,000 kw is obtained from three ( stations, two located on the Delaware River on the western edge of the territory. Outdoor weather-prolei : The Deepwater Station, near Penns Grove, has a capacity of 213,500 kw; the motors drier the draft Jar Greenwich Station, at Gibbstown, has a capacity of 10,000 kw, and the Missouri .4/ left, a 1500-hp, 720-rf Avenue Station in Atlantic City rates 94,500 kw. motor drives an i-dfan, a The Missouri Avenue Station was featured in an article in the Autumn 1947 at right is a 500-hp, Is rprn motor driving aforce issue of Powerjax. It uses Elliott deaerating heaters, turbines, and motors. Pictures draftJan. Deepwater Slat, here show some of the Elliott equipment installed in the Deepwater and Greenwich Stations. These two stations are an interesting contrast in the use of | steam-turbine-driven and electric-driven auxiliaries. Since the Greenwich Station operates a 10,000-kw, 175-psig back-pressure noncondensing unit, and furnishes 4 POWERFAX. WINTER 19SS steam supply for industrial use, it makes use of steam auxiliary drives. The Deepwater Station, however, houses alxntt 185,000 kw of capacity in condensing units in addition to back-pressure turbines for the supply of process steam for industrial use. This station uses the conventional electric motor drive for auxiliaries. Many of these motors are located outdoors. The Elliott motors at Deepwater were installed in connection with a new 75,000-kw turbine-generator which went into service at the end of 1954. There is an Elliott 700,000-lb-perhr deaerating feedwater heater in the Greenwich Station. Three Elliott 9CO-bp, 3600-rpm squirrelcage induction motors driving boiler- feed pumps in the Deepwater Station. lien Elliott !06-hp, 3550-rpm turbines driving boiler-feed pumps in the Greenwich Station. Turbines take steam at 775 psig, 570 F, and exhaust at 35-psig back pressure. Turbines are suitable for future 700 F operation. I A / At vr* /ii ///// Mt-Aft. 511- Tpm vertical nutdoor uratherprotected motors drive circulating pumps at Deepwater Station. There are also two Elliott I5Mp, JdtJO-rrnp motors driving the condensate pumps. Two Elliott 2U3-hp. geared turbines driving Jorced-draJt Jans at Greenwich Station. Turbines operate at 3570 rpm. which speed is reduced to 1250 rpn\ on the Jans. Steam conditions same as mentioned Jar boiler-jeed pump drives. One of tu^i Elliott J5()-hp, 3570-rpm turbines driv ing induced-draft Jans at Greenwich Station. Gears reduce speed to 850 rpm. Turbines exhaust at 55p ug. B Thisphotograph shows an Elliott 20-in. twin strainer, one of several installed at Greenwich. 7 hr strainer handles cooling water and is installed outdoors. POWERFAX. WINTER 1955 Arkansas Power and Light Co. operates four major steam-electric stations totaling 768,000 kw capa bility. The Cecil Lynch Station (capability 242,000 kw) is located near North Little Rock. The Harvey Couch Station, at Stamps, (written up in Winter 1944 Powerjax) has a capability of 169,000 kw. Both sta tions were expanded in 1954 by 135.000 kw each. It is interesting to note that each of these generating units is capable of producing more power than the company's entire territory required prior to World War II. Other plants of the company include the Lake Catherine Station located near Malvern, with a capa bility of211,000 kw, and theHamilton Moses Station at Forrest City, with a capability of 146,000 kw. The com pany also operates two hydroelectric plants, located on the Ouachita River at Hot Springs, which total 69.000 kw capability. The company is a part of the Middle South system, and this entire system is operated as an integrated unit, thus making available to each company the reserves of any of the other companies. Load forecasts are made at regular intervals, and addi tional generation is added from time to time as needed to take care of the Middle South area. The Arkansas Power and Light Co. serves 735 communities in 61 counties, including 14 rural co-op systems. At the end of 1954, its rural lines totaled 17,989 miles. The company serves approximately two-thirds of the geo graphic area of Arkansas. It supplies electric power to more than 239,000 domestic consumers in addition to industrial and commercial users. The company employs 2898 people and figures the investment per job to be 580,211. The new generating units at the One of the two Elliott 1500-hp, 900-rpm weather-protected {outdoor splashproof) motors driving forced-draftfans in the Harley Couch Station. vieiv of the three Elliott 2000-hp, 3600-rpm induction motors driving the boiler-feed pumpsfor the latest unit in the Harvey Couch Station. This Elhutl I5tl0-hp. fttfj-rpm weather-protected squirrel-cage induction motor is one oj lien driving Jnrred-droJlfans for the latest addition at Cecil Lynch. II Cooling tower Jorms background Jot these two Elliott 1250-kp, 450-rpm vertical squirrel-cage induction motors driving the condenser circulating water pumps at the Harvey Couch Station. Cecil Lynch and Harvey Cloud Stations have boilers equipped wit! burners which use either natural ga_ or fuel oil. Construction permit future addition of coal-handlins equipment. Modern in every respect the generating units were built at r cost comparable to 10 years ago which points up the economies o expert engineering design and de velopments. Outdoor-type construc tion eliminated high cost buildings with all major equipment operatint in the open. The Cecil Lynch Station went inti service with its first unit, 31,250 kw in May 1947. Its second unit 66,000 kw, went on the line in Jul) 1949; and its latest unit, 125,00( The three Elliott 350-hp, 1200-rpm vertical motors driiing the condensate pumpsJot the new unit at the Harvey Couch Station are shown at the left. I name-plate rating, went on the line in June 1954. Steam conditions for the first two units were 850 psig-- 000 F at the throttle. The No. 3 unit uses 1450 psig--1000 F. The two smaller units are located at main building roof level and are housed in a room whose roof may be removed for turbine maintenance work. The * large unit is installed outdoors. Out put of the station is fed into the Arkansas Power and Light Co. trans mission system through power trans formers at 110,000 and 161,000 volts. The boilers are of the semi-outdoor type. With the exception of firing aisles, all parts of the boilers are out side. The principal fuel is natural gas, but equipment is installed to burn fuel oil in an emergency, and space has been allowed for future coal burning equipment. Boilers on the two smaller units arc equipped with both forced- and induced-draft fans, while the large unit has only forced-draft fans. The station uses cooling towers, with water routed to and from them through underground concrete pipes. The condenser cooling water systems circulate 10,980,000 gph between condensers and cooling towers. -Vlake- / hoe are 111i two mull IJStt-hp, IHH-ijim reeticnl i atha-pioh i I'll molarwhich ill nr llu circulating water pumps a! Cecil Lynch They are unlatled iiutil'ni i alongside ike cooling hacer. 7 hree Elliott J000-hp, 3600-rpm meatliei-protected squirrel-cage induction motors drive the hr,tier-Jred pumps at the Cecil Lynch Station. 11 Three Elliott .iStt-hp, UtKErfm vertical weather-protected induction motors drive the condensate pumps installed at Cecil f.ynch Station. up to the system is about 1.7 percent, or 4,500,000 gpd. This make-up is pumped from 12 deep wells and is chemically treated for the removal of iron before entering the cooling- water cycle. Approximately 9000 lb of chemicals per day are required for this treatment. In addition, a rail road tank car of acid is used about every two months. Some of the larger Elliott motors driving auxiliaries for the new units in the Harvey Couch and Cecil Lynch Stations are illustrated. In addition to these, Elliott C-YV motors, in sizes from 1 hp to 100 hp, are driving cooling tower fans, com pressors, lube oil transfer, and fuel oil recirculating pumps. Engineers and constructors for these stations--Ebasco Services, Incorporated. **< This Elliott 250-hp, 1200-rpm weather-protected squirrel-cage induction motor drives the gas recirculating Jan at the Cecil Lynch Steam Electric Station. 12 POWERFAX, WINTER 195S I 7 hree Elliott motors drive the compressors jor the refrigeration units in the plant. The Elliott 10-hp motor in right foreground is driving a compressor for the refrigerated storage space. A'exl in line is the Elliott 30-hp motor driving a reciprocating rotary compressor and, third, is an Elliott 25-hp L motor driving another reciprocating multi cylinder compressor. The last two com pressors are part of the refrigeration equipmentfor the quick-freezing room. Freezing bread to keep it fresh It is possible that many Powerfax readers have discovered that by putting- a loaf of bread in the refrigerator it will retain its freshness over a long period of time. This simple household trick has now been put into full-scale commercial operation at the new bread freezing and storage plant of Arnold Bakers, Inc. in Port Chester, New York. The new plant covers nearly 9000 sq ft and is designed to provide 12,000 cu ft of refrigerated storage space in addition to a quick-freezing room, packing room, a truck bay, and compressor room. The entire "cold box" area, consisting of freezing, packing, and storage rooms, is entirely enclosed by insulated walls, ceiling, and floor. After the loaves of bread are removed from the oven and allowed a normal cooling period to prepare for slicing, they are individually wrapped and placed on racks which are then wheeled into the freezing room. There the bread is quickly frozen at minus 20 F. The racks are then moved to the adjacent pack ing room where the frozen loaves are put into cartons. From the packing room, the cartons arc taken to the storage room where the frozen bread is kept at zero F until ready for shipment. There are conveyors to handle the bread from the quick-freezing room to packing room, and the packed cartons from the packing room to storage. Freezing capacity of the quick-freezing room is 1000 lb per hr at minus 20 F. Two compressors are required for refrigerating this room. The first-stage compressor is a rotary unit with a 206-cfm displacement, V-belt driven by an Elliott 30-hp motor. The second stage, a multicylinder reciprocating unit with 73-cfm displacement is driven by an Elliott 25-hp motor. One compressor only is required for the storage room refrigeration system, and this is driven by an Elliott 10-hp motor. Arnold Bakers, Inc. pioneered the sale of quick-frozen bread on a commercial scale approximately two years ago, using public facilities in another city for storage of its frozen products. Now that Arnold has refrigerated storage space right at the bakery, bread can be frozen at the peak of its freshness and faster service can be given distributors, especially on those items where demand fluctuates widely. Frozen bread is shipped in refrigerated trucks to Arnold * distributors in cities beyond a 400-mile radius of Port Chester. Within the 400-mile radius, Arnold distributors generally do not sell frozen products. Information and photographs for this article were obtained from Industrial Refrigeration POWERFAX, WINTER 1955 i These racks of bread are being quickfrozen at 20 degrees below zero in the quick-freezing room of the new refrig eration and storage plant of Arnold Bakers, Inc., Port Chester, .V.T. 13 This photograph shores the bottom oj Jour uj the ten ejectors. These units act as steam jet compressors. compressing Jtue gas Jrorn the kiln and delivering malice gas at a constant rale to the lift system. The mixture offlue gas and steam from the thermocompressors lifts the catalyst to the top of the Humlrifkac unit. Ten large Elliott single-stage ejectors are used on the Houdriflow unit. They are installed about 100ft above ground in two banks offive ejectors each. This photograph shows tops offour ejectors. 1 the turbine jj turbine-driven \f u-mbustion air fit. up at right. **, inlet pressure tjpsia. Turbine V trd exhausting ,af backpressure. Neoprene lining overcomes salt water corrosion These detailed views of the water box of an Elliott 7000-sq ft surface condenser show how it was equipped for use in a plant along the sea coast. To offset corrosion troubles the interior of the water box was coated l{6 in. thick with seamless Neoprene rubber coating. The faces of the flanges were also coated so that it was not necessary to use gaskets. The coating was sprayed on, and after each application, .005 in. thick, the material was cured by infrared heat. Before applying, all the surfaces were sandblasted to remove loose scale and dirt. In view of the use of salt water for cooling, aluminum brass tubes and Naval brass tube plates and water-box stays were used in the condenser. Condenser in a petrochemical plant This good-looking Elliott condenser installation is in a southwest Gulf Coast petrochemical plant. The con denser serves a turbine driving a cen trifugal compressor, which is mount ed on the balcony above the con denser in outdoor location. It is one of a dozen divided water-box surface condensers ranging in size from 8800 to 11,000 sq ft furnished this large plant for similar service. At lower right may be made out a couple of Elliott mechanical-drive turbines driving condensate pumps. 19 In the Cxomby Stath rim- of ll,r river-writer pumps in Ike Cromby Slat,on serving Lnrtsl ana - humps, rated &W gpm, %>*, are driven by Elliott Crocker-H heeler J f rttO-rbrn JtXtO-voll vertical motors. Smaller units in center are fire frumps. -IZnnr ofi the nver-water pumps areJour Elliott 20-in. selj-cleaning steamer POWER?AX, WINTER : . element. Heaters for the six-stage re trol room which i\ completely en tin- two boilers tire televised to the generation cycle are located in the closed except for two small windows control room. turbine room. Final feedwater tem facing the boilers which allow a mir Both the mechanical and electrical j perature is 500 F. rored view of the furnace fire through installation were designed by the en The hydrogen-cooled generators ol.iservation doors on the boilers. gineering department of tin- Phila generate at 20 kv. Each generator These windows allow a line of sight delphia Electric Company. The gen feeds its power to a separate outdoor for the conventional water-level mir era! contractor was United Engineers substation through its own unit step- ror system. The water columns for & Constructors, Inc. up transformers. Excitation is from separate motor-driven exciters of the flywheel type, three being provided for the two generators. Since all boiler and turbine auxilia ries are motor driven, a sizable aux iliary power installation is required. Motors rated 200 hp and above are supplied from a 4-kv system, and smaller integral horsepower motors J! from a 440-volt system. Indoor motors are splashproof ex cept where near oil or inflammable materials. Outdoor motors above 200 bp operate at 4 kv and are of the weather-protected, air-cooled design, while smaller outdoor motors arc fed at 440 volts and arc totally-enclosed, fan-cooled. Boiler, turbine, generator, auxil iary power, and substation controls are concentrated in one central con i' j t j i 22 Thu is on* of hio Elliott ISffll-hp, 710-r/im. fltjG-K.lt motors .huing induced-draft juris serving L nils 7 and S in the Delaware Station. .1 close-up of one of thefour Elliott JO-tn. self-cleaning strainers which are located on the discharge side of the vertical river-water pumps. These strainers clean themselves constantly, the motor on lop slowly turning a rotating element, thus permitting backjlushing nj the straining ele ments. Dirt and debris are discharged through a drain at the hattom. Elliott motors power new hydraulic forging press A new 2000-ton forging press built by Loewy Hydropress. Inc., is now busy making smaller billets out of bigger ingots at the Universal Cyclops Steel Company plant at Titusville. Pennsylvania. This new press, which will deliver over 100 blows per min ute, is the only modern forging press in the United States designed pri marily for forging tool steel and high temperature alloys. It rests on steel pilings filled with concrete which were driven to a depth of 50 feet, its base requiring 400 cubic yards of concrete. The care and feeding of this huge mechanism requires four heating fur naces, an annealing furnace, a charg er, a manipulator, a 40-ton overhead crane with a seven and one-half ton auxiliary hook, high lifts and a unit for pumping water to a pressure of 4200 psi. All of this is inside a new building measuring 200 ft by 90 ft and 50 ft high, especially constructed to house the monster. However, for all the considerable amount of equip ment involved, a crew of only six men is required for the operation of the forging press. The water unit is housed in its own room next to the press, where the main pieces of equipment are two hydraulic pumps driven by Elliott 600-hp, 1200-rpm synchronous mo tors. Water is pumped at a pressure of 4200 psi into a "bottle" having steel walls eight inches thick. The cushioning air at the top of the bottle is supplied by a horizontal V-bcltdriven air compressor. The compres sor drive is an Elliott C-W 40-h[ motor. The press has enabled Universa Cyclops to handle larger-sized ingot and billets which it could not proces before. These ingots, cast at the com pane's Bridgcville, Pennsylvania divi sion and alloyed to the customers ex act specifications, arrive at Titusvili either by rail or truck. After the in guts are ground to remove scale, the are delivered to the building whicl houses the forging press. Here eacl ingot is placed in an automatical! controlled gas-fired furnace for abou 24 hours and heated to proper forg ing temperature. After the right temperature i reached, the charging machine re moves the ingot from the furnace an 24 POWERFAX, WINTER 19S A pilot exciter without a commutator One of the principal causes of turlx>- generator outages over the years has been the failure of pilot exciters. The usual compound-wound d-c pilot ex citer has been a machine of small physical size with a commutator prone to give poor performance and subject to excessive brush wear and commutator maintenance. This is because, first, the brushes used must, for mechanical reasons, be large in size. Secondly, at least two brushes per polarity must be used to permit brush-changing under load. Finally, since pilot exciter current output is low, the current density in the brushes is abo low. And especially at low current density, the numerous large brushes wear out quickly and groove the commutator rapidly. A perma nent magnet exciter by eliminating these problems, can improve overall unit reliability. Elliott Company is supplying with An Elliott permanent-magnet type pilot exciter, mounted on a common base with a conventional main exciter. Pilot exciter, of course, needs no commutator or brushes. its larger turbine-generators an ex citation system in which the con ventional pilot exciter has been re placed by a permanent-magnet type a-c generator. At 3600 rpm, it de livers 120-cycle, 3-phase current at approximately 110 volts. This volt age is rectified by a selenium rectifier assembly and introduced into the field of the main exciter. Voltage is controlled by a standard indirectacting, rheostatic-type regulator. The voltage characteristics of the permanent-magnet generator and rectifier approximate those of a com pound-wound, d-c pilot exciter as out lined in industry specifications (AIEE Numbers 601 and 602, page 55). Actually, the change in voltage with speed is better than required, since, at 90 percent rated speed, voltage drops only to 90 percent. From full load to no-load, voltage will in crease approximately 15 percent, but this has no effect on performance since a rheostat or voltage regulator controb current flow into the main exciter field. The rotor of this new pilot exciter consists of a steel hub, four Alnico permanent magnets, four steel pole shoes, and 24 nonmagnetic capscrews. (Magnetic cap screws would shortcircuit the permanent magnets.) The rotor is designed for overhung mount ing on an extension of the main ex citer shaft, hence requires no coup ling or bearing. All other parts of the pilot exciter are static. The stator frame contains a core and winding of conventional three-phase design. The rectifier 26 POWERF/OC, WINTER I9SS J H. Schneider, Section Engineer, Ridgway Division, Elliott Company The pilot exciter rotor consists oj Jour . llnico permanent magnets, no field windings being necessary. Schematic sketch o] circuit employing the permanent-magnet type a-c generator as a pilot exciter. Generated a-c is rectified by rectifier, Jed into main exciter field. assembly provides three-phase, fullwave rectification. For mechanical protection it is mounted in an en closure with a removable screened top. This cover gives easy access to the internal connections and permits adequate ventilation. In order to assure long rectifier life and to mini mize the increase in voltage with de creasing load, the rectifier is large and conservatively designed for this service. It need not be located near the exciter, although it is usually mounted in the excitation cubicle. Aside from its low maintenance cost, another feature of this a-c pilot is that it cannot be damaged by over loading or short-circuit. The stator windings are liberally designed to withstand overcurrents and, ofcourse, no field windings are required. The only result of overloading or shortcircuit is to partially demagnetize the rotor magnets. Magnetism is readily restored, at standstill, by "flashing" one phase of the stator winding from a storage battery', the rotor poles having been lined up with respect to a designated point on the stator. The first installation of the Elliott permanent-magnet pilot was made in 1953 as part of an excitation system in a municipal plant. Since then, four other units have been put into operation in connection with Elliott hydrogen-cooled turbine-generator installations. Excellent results have been reported in each instance. The pilot, with conventional main exciter, will give an ASA nominal exciter response of 0.5 or higher. Three-phase, Jull-wace selenium rectifier assembly concerts 120-cycle pilot exciter voltage to direct currentJor the main exciter field. POWERFAJC, -WINTER 1955 Coal barge unloaders use adjustable voltage system Sometime shortly after the New Year, the Ohio Valley Electric Corporation will complete construc tion of the two largest power plants ever built by private enterprise. These two stations, Clifty Creek plant at Madison, Indiana, and Kyger Creek plant at Cheshire, Ohio, actually started delivering power to the U. S. Atomic Energy Commission's gigantic new uranium diffusion plant near Portsmouth, Ohio, early in 1955. The first 215,000-kw generating unit at each plant was placed in operation last January--ahead of schedule--and subsequent units since have gone into service, also ahead of schedule. Upon com pletion, Clifty Creek will have six units totaling 1,290,000 kw, and Kyger Creek will have five units totaling 1,075,000 kw. The two power plants, which are 175 miles apart, as the crow flies, and the A.E.C. Project, which is located between the two plants, are interconnect ed by a double-circuit system of 330,000-volt trans mission lines--the highest voltage lines now in service in this country. OVEC was organized in 1952 by 15 private electric utility companies of the Ohio Valley region for the single, specific purpose of supplying the full and tremendous electric requirements of the thenproposed Portsmouth Project. Clifty Creek, Kyger Creek, the transmission system, and other OVEC facilities will cost approximately $400,000,000. The two completed plants together will burn an estimated 7JA million tons of coal a year, all of which is to be delivered via barges upon the Ohio River. Elliott Company is furnishing many motors for driving powerhouse auxiliaries, ten deaerating heaters, each rated 1,000,000 lb per hr, and self-cleaning strainers Tor use in these outstanding stations. This article will deal only with the coal barge unloadcrs--two for each station --which were designed, built, and erected by Hcvl & Patterson with Elliott Company furnishing the adjustablevoltage motors, generators, and control. This equipment insures high-speed precise operation of the coal unload ing and handling operation. These coal barge unloaders remove coal from river barges to a 200-ton capacity receiving hopper built in- One of the two coal barge unlaaders at Clifty Creek station. Designed, hull, and erected by Heyl <2? Patterson, Inc., Pittsburgh, it is rated 1J00 tons per hour and uses an 11-tan grab bucket. Motors, motor-generators, and control are in the house at lop. Operator's cab may be seen below and to the left of this, with a walkway extending off to the right. 28 This is the file-unit, adjustable-voltage, motor-generator set which consists of a 100-hp. /150-rpnt, 2.s!X)-volt squirrel-cage induction motor driving two 2tXTku\ sJo-volt d-c motors Jar the hold and close drives, one 75-ktc special variable-voltage auxiliary generatorfor trolley drive, and a 15-kic. 250-volt d-c exciter to supply power for the motor fields. Set is located adjacent to motors and control cabinets. t tegraily in the unloader. The coal stunt-potential exciter which provides brake to hold the loaded bucket if ` flows from the hopper by gravity to a the necessary excitation for the reg the other brake fails. * 54-in. belt feeder, then to a 48-in. ulators. motor fields, brakes, and The hold and close drives provide i belt conveyor which delivers it to the control circuits. five speed-control points in each power-plant bunkers. All driving motors are 600 series, direction with protection against The troliev in the stationarv tower heavy-duty mill motors, and the gen motor field loss, overload, overspeed, 4. ' * - is rope-operated and the 12-ton grab erators of the m-g set have special loss of power, and hoist overtravcl. ; bucket operates from two drums with characteristics suitable for regulator Regenerative braking is provided ; a counterweight on the hold drum, control and the peak capacity of for overhauling loads in the lowering i. The equipment is designed for a 37- these motors. direction. The master switch con second cycle for a free digging rate of The generator fields are controlled tacts directly control the pattern ex ? 1100 tons per hour with a trolley by rotating regulators. These control citation of the regulators, which in travel of 36 ft and a lift of 73 ft. the rate of acceleration and deceler turn control the generator fields to The barge unloader is operalec ation, limit the current peaks, and provide the functions previously out from an operating cab by means o regulate the generator voltage. The lined. Adjustments of speed can be master switches which actuate elec system provides smooth operation, readily made by adjusting small con trical equipment in the house on top o simplifies the control, and reduces trol resistors located with the master the tower. Elliott Company furnish maintenance. switches. The regulators arc adjusted ed the motors, generators, and ad D-c-operated, floor-mounted, for load division so that 50 percent of justable-voltage control equipment shunt-wound brakes are provided for the load is taken by the closing line In this system, the motor-gcncratoi all motions. The trolley travel motor motor and 50 percent is on the hold set might be called the heart of the has a continuously rated shunt brake, ing line motor. The same ratio of equipment. It is a five-unit set includ and the closing and holding line load division is maintained when ing individual generators for the close, brakes, which are duplicate, have lowering a loaded bucket, provided hold, and trolley drives, plus a con- sufficient capacity for the close line the master switches are on the same POWBtfAI. winter I9S5 29 This view inside llie house on /</ of the coal lunge unlmitlrr sltmcs the two Elliott 1H7V>-hp. farced-ventilated, separately-excited hold and close drive mill-ty/ie d-c motors. These motors are operatedat approximately 345 volts and OSS rpm. They drive the dram through gears. Urates are shown at lejt and a hoist-limit milch mar he seen on base plate between motor andgear. .1 little of the motor-gem tutor may he seen in the background. In /r/t foreground is the Elliott D-l-hp. '.sO-volt selfveniilaled, separately-excited mill-type d-c trolley motor, which is operated at approximately 317 volts and 710 rpm. Control cabinets in background (doors of one arc open). point, and the bucket remains closed. A loadsensitive relay insures that both the hold and close line drives operate at the same speed when lowering a light open bucket.' When lowering an empty bucket, it is possible to open or close the bucket by setting the hold and close master switches on different points. The trolley drive is controlled by regulators similar to those on the hoist drives and is arranged for normal stopping by regenerative braking. Automatic deceleration and stop circuits arc established at each end of the trolley travel when the trolley enters these zones at speeds above predetermined values. The hold line and the close line are each driven by a 187^-hp mill-type motor which receives its power from a separate 200-kw, 345-volt adjustable-voltage generator. Each generator's excitation is controlled by a rotating-type voltage regulator. These regulators receive reference voltage signals from fivepoint speed hold and close line masterswitches. The regulators compare these reference voltages with the actual voltages across the two power loop circuits and excite the fields of the generators so as to maintain the loop voltages at the desired value as dictated by the position of the master switches. Normal braking torque on the hoist drives is provided by regenerative action in the hold and close d-c motor-generator power loop circuits. Individual dynamic braking for each motor provides emergency stopping. Limit switches in the hoist controls are used for slowdown and final limit of upward travel of the bucket. Dynamic braking is applied to the hoist motors when the limit switches operate for final stop. Voltage relays protect each motor against overvoltage and con sequent overspeed. Motor field loss, over current, and undervokage protection are also provided. The trolley is powered by a 94-hp mill-type motor supported by a 75-kw, 320-volt gen erator. A rotating-type voltage regulator con trols the generator field circuit and operates in the same manner as described for the hoist generators. Normal braking torque is by regenerative action in the power loop. Dynamic braking with excitation of the trolley motor field from the trolley motor armature is provided for emergency braking. Overspeed, overcurrent, and undervoltage protection are provided. 30 powerfajc, winter iws The salrsclcrk tried to be helpful when the lady was looking for a suitable Christ mas gift for her grandfather; -How- about a tie, madam?" he asked. -No, he has a beard." -A pullover might be the thing." -No, it's a very long beard." ,-j sfCi madam," said the salesman wea- rilv. "Do you think a pair of spats would show?" A Russian named Rudolph looked out die window one morning and said, "It's raining." * No, it's sleeting," said his wife. "It's raining, doggone it," he answered, and Rudolph the Red knows rain, dear." Christmas Philosopher: "You know, there are bigger things in life than money." Cynic: "Oh, yeah, what?" Philosopher: "Bilb." It's the little things that bother And keep us on the rack; We can sit upon a mountain But not upon a tack. An Australian trying to impress a visiting Texan with the wonders of his country wasn't having much success until the Texan saw a kangaroo. "Ah'll grant you one thing, anyhow," said the impressed Texan, "your grass hoppers are a inite bigger than ours." 4 Real estate salesman: "Would you like to see a model home?" Prospect: "Glad to. What time docs she get off work?" Speaker: "Is there any man in the house who would let his wife be slandered and say nothing? If so, please stand up." A meek little man rose to his feet. Speaker: "Do you mean that you would let your wife be slandered and not do any thing about it?" Meek Little Man: "Oh, pardon me, I thought you said slaughtered." 4 The bride, white of hair, is stooped over her cane; Her footsteps, uncertain, need guiding, While down the church aisle, with a wan, toothless smile, The groom in a wheel chair comes riding. And who is this elderly couple just wed? \ ou'U find when you've closely explored it. That here is that fare, most conservative pair Who waited till they could afford it. When the lady who was making out the application came to the little square headed "Age" she didn't hesitate. She simply wrote "Atomic." 4 Wife: A woman who braves wintry blasts in nylons but who requires 85% of the bedclothes, 4 As one of our friends said: "If we hadn't expanded, we'd think we were really going to town with today's business." 4 The hardest job modern children face is learning good manners without seeing any. Passing a run-down store in a distant city, a well-known artist noticed a mangy little kitten lapping up milk from a saucer. The saucer, he realized with a start, was a rare and precious piece of pottery. He sauntered into the store and offered two dollars for the cat. "It's not for sale," said the proprietor. "Look," said the collector, "that cat is dirty and undersirable, but I'm eccentric. I like cats that way. I'll raise my offer to five dollars." "It's a deal," said the proprietor as he pocketed the five-spot. "For that sum I'm sure you won't mind throwing in the saucersaid the connois seur. "The kitten seems so happy drinking from it." "Nothing doing," said the proprietor firmly. "That's my lucky saucer. From that saucer, so far this week, I've sold thirtyfour cats." 4 First Boarder: "This cheese is so strong, it could walk over and say `Hello* to the colfee." Second Boarder: "Y'es, but the coffee is too weak to answer back." Life is like that. Y ou usually hear about the man who hits the jackpot, but the fellows who built up the pot are unknown. 4 A friend reports he learned all about relative humidity when he held his infant daughter on his lap. 4 "Hr says I don't know how to dress, huh? Tonight 1 11 wear my low-cut dress and show him a thing or two." 4 A young lady down our street slipped on the ice yesterday. It bruised her somewhat, and slightly injured her otherwise. The little man was pushing his cart through the crowded market. "Coming through," he called merrily. No one moved. "Gangway!" he shouted. A few men stepped aside. Ruefully he surveyed the situation and then smiled as a bright idea struck him. "Watch your nylons!" he warned. The women scattered like chaff in the wind. 4 Miami: A land flowing with silk and money. 4 A lot of brainy women earn their living, but the sensible ones let men do it for them. 4 The modern idea of roughing it is to sleep without an electric blanket. 4 A couple of young boys walked into the dentist's office and one faced boldly up to the demist and said, "Doc, I want a tooth took out and I don't want no gas 'cause I'm in a hurry." "My," said the doc, "I must say you're a brave boy. Which tooth is it?" The little boy turned to his silent friend and said, "Show him your tooth, Albert." POWERfAX, WINTER 1955 31 STEAM TURBINES - Turbine-Generator Units--Mechanical Drive Units--High-Speed Reduction Gears ELECTRICAL EQUIPMENT Motors (1 hp to largest)--induction, wound rotor, synchronous, d-c, brakemotors, geannotors--Generators (all tv a-c and d-c)--Motor-Generators--Synchronous Condensers--Electromagnetic Slip Couplings HEAT TRANSFER APPARATUS Condensers and Ejectors--Deaerators and Deaerating Feedwater Heaters INDUSTRIAL PROCESS EQUIPMENT Centrifugal Compressors--Steam Jet Ejectors--Condensing Equipment CENTRIFUGAL COMPRESSORS AND EXPANDERS Air Compressors--Gas Boosters and Exhausters--Compressors and Expanders for Process (Electric motor, steam, gas turbine driven) TURBOCHARGERS AND SCAVENGING COMPRESSORS FOR DIESEL ENGINES Turbochargers for Two-Stroke Cycle and Four-Stroke Cycle Engines--Scavenging Compressors for Two-Stn Cycle Engines STRAINERS--fllTBCS Strainers (Twin, Single, Oil, Self-Cleaning)--Filters and Grease Extractors TUBE CLEANERS AND TUBE ACCESSORIES Cleaners for Tubes in Boilers, Oil Stills, Condensers; for Pipe, etc.--Tube Expanders, Gages, Plugs, etc. COUPLINGS C-W Resilient Flexible ELLIOTT Descriptive bulletins of any of these product* will gladly be sent upon request. COMPANY JEANNETTE, PA. Turbinas, Heat Transfer Equipm !Headquarters, including Turbochargers, Accessories, Mof Crocker-Wheeler Division Generators, A Flexible Couplin' RIDGWAY, PA. RidgwayDivision l Machinery SPRINGFIELD, OHIO Lagonda Division {Tube Cleaners, Expanders, etc. NEWARK, N.J. Roto Division (Tube Cleaners DISTRICT OITICES Atlanta 3....................................310 Haas-Howell Building Bloomfield. N.J..............................400 Bloomfield Avenue Boston 35........... .......................... 1330 Soldiers Field Road Buffalo 2................................................807 Crosby Building Charlotte, N.C......................... 1707 Liberty Life Building Chicago 30.......................................... 6100 N. Pulaski Road Cincinnati 6.........................................2337 Victory Parkway Cleveland 14...............1319 National City Bank Building Dallas 5........................................ 5738 Central Expressway Denver 3.................... 306 Union National Bank Building Detroit 26............................................... 1820 Dime Building Duluth.................................... 617 North 10th Avenue, East Houston 3............................................ 1209 Hutchins Street Indianapolis 8......................................... 54 West 30th Street Kansas City 14..................................... 514 West 75th Street Los .Angeles 15............*%.................714 W. Olympic Blvd. Milwaukee 3...............................................744 N. 4th Street Minneapolis 3.................................540 Plymouth Building New Orleans 13........ -.................256 Lee Circle Building New York 13......................................... 271 Church Street Philadelphia 2........ 226 South Sixteenth Street Building Pittsburgh 19........................................... 718 Frick Building Rockford, 111............403 Central National Bank Building San Francisco 4............................ .. .1504 Russ Building St. Louis 3.................................................1221 Locust Street Seattle 1............................................... 1101 Vance Builc Syracuse 2.................................. 317 State Tower Builc Tulsa 3............................................ 910 Petroleum Builc Washington 1, D.C........Washington Gas Light Builc REPRESENTATIVES Montreal, Que.................... F. S. B. Heward & Co., 1 620 Cathcart Si Toronto 2, Ont. ... . ,F. S. B. Heward Si Co., 1 1835 Yonge St Havana, Cuba................. v..........Compania Importac Skilton, S.A., P. O. Box 2 . Mexico, D.F................................. Tecnica y Equipos, f Monterrey 101- San Juan, Porto Rico..................................................Abj Warehouses Corp., P. O. Box 2 Buenos Aires, Argentina.................. .. .Mechanical W Engineering Co., Avenida Julio A. Roca Rio de Janeiro, Brazil............ Casa Mayrink Ve:ga, : 17 Rua Mayrink Veig- Santiago, Chile, S.A...........................Compania Mine Commercial Saii Hochschild, S.A., Casilla - Athens, Greece. .Miltos P. Pesnikides, 20 Onurou Si Honolulu, T. H.. - Hawaiian Equipment Company% Manila, Philippines................ .Atkins, Kroll & Co., 124 Myers Building, 12th Street, Port i Export Branch.......`........... : .. New York C Approved service shop* and distributor* strategically located throughout the United States. Printed in. I