bluuebunny/crossref_metadata_2025_split huggingface dataset:
External Corrosion of Furnace-Wall Tubes—II Significance of Sulphate Deposits and Sulphur Trioxide in Corrosion Mechanism
Authors: Corey R. C. , Cross B. J. , Reid W. T. 
Published: December 2022

Abstract
The external corrosion of furnace-wall tubes of slag-tap furnaces became a problem to operators and manufacturers in 1942. Since that time, in order to determine the mechanism of corrosion so that rational protective measures could be developed, an extensive laboratory study has been in progress on the sulphate, or “enamel,” deposits found on the tubes in areas where external corrosion occurs. These deposits are greenish-white to reddish-brown in color and are soluble in water, in which they produce an acid reaction. X-ray diffraction studies show them to consist primarily of a solid solution of sodium and potassium sulphates and alkali-metal ferric trisulphates, such as K3Fe(SO4)3. Experiments under controlled laboratory conditions with actual and synthetic “enamels” have shown that, at temperatures of 1000 F, sodium and potassium sulphates will react readily with iron oxide in an atmosphere containing a low concentration of sulphur trioxide to form the same alkali-metal ferric trisulphates that occur in “enamels.” However, under the same conditions of temperature and concentration of SO3 neither iron oxide nor the alkali-metal sulphates alone will react with SO3. These reactions suggest the mechanism of corrosion to involve the removal of the normally protective oxide on the furnace tubes by (a) the condensation on the relatively cool tubes of alkali-metal oxides which are converted to the corresponding sulphates by the SO3 in the furnace, and (b) the subsequent reaction of the iron oxide on the tubes and the alkali-metal sulphates with the SO3 evolved as the result of the slagging reactions in the coal ash deposited mechanically on the “enamel.” Thus conditions are afforded for the removal of the iron oxide on the tube with the formation of alkali-metal ferric trisulphates. Deslagging causes thermal decomposition of these compounds, and the cycle is repeated. It is suggested that prevention of corrosion by this process can be achieved by ventilating the surface of the tubes with air so as to decrease the concentration of SO3 below that necessary for the formation of the complex iron sulphates. Also, because the alkali metals required for the reaction are believed to originate principally from the flame, the addition of such air decreases the rate of deposition of alkalies. These findings are in agreement with field observations in which the maintenance of oxidizing conditions prevented further corrosion.
Helical Taper Reamers Milled With Constant Helix Angle
Authors: Githens Thomas F. 
Published: December 2022

Abstract
The author explains the process of milling helical flutes on a taper reamer so that the flute will have a constant helix angle of 45 deg at every point along the length of the reamer. The problem is solved by the development of a former or master cam cylindrical in shape and bearing upon its lateral surface a helical groove such that, as the cylinder turns on its axis with constant angular velocity, the whole former advances in the direction of its own axis at a controlled but variable feed. The milling cutter is mounted so that its plane forms a constant angle with an element of the taper blank being machined to form the reamer. The advantage of the method described is its adaptability to a quick practical solution either mathematically or by graphical means.
Experience With Sodium and Potassium Chemicals for Boiler-Water Conditioning at Montaup Electric
Authors: Parks G. U. 
Published: December 2022

Abstract
Since its installation in June, 1942, the high-pressure forced-circulation boiler at Somerset Station of the Montaup Electric Company, which is designed to produce 650,000 lb of steam per hr at 1950 psi, has been of considerable general interest, because of certain unique features in power-plant practice. Operation for the first 9 months, using standard sodium chemical treatment for water conditioning, was unsatisfactory. A potassium treatment was evolved, which corrected the adverse conditions. Today the Somerset Stations’ high pressure boiler is in every respect an excellent commercial steam generator.
Water-Hammer Problems in Connection With the Design of Hydroelectric Plants
Authors: Strowger E. B. 
Published: December 2022

Abstract
A review is given of the subject, based upon previously published papers, and in addition Allievi charts, which have been extended to include practically all problems an engineer may consider, are presented. The review covers, among other things, a simple statement of the fundamentals of the problem as usually encountered in hydroelectric plants, an explanation of the arithmetic-integration and graphical methods, and the solution of the surge-tank problem. Other aspects of the subject, such as the influence of gate motion, pressure conditions along the pipe, etc., are discussed. Emphasis is placed upon presenting to the designing engineer definite and useful procedures for the solution of some of the more common and simpler water-hammer problems in connection with hydroelectric plants. The arithmetic-integration method is set forth because it is a useful method per se and is a prerequisite to a ready understanding of the graphical method. The solution of the surge-tank problem is given by reference to the Calame and Gaden approximate formulas. These formulas, as published in English at the present time, contain several typographical errors and, consequently, may be misapplied. For this reason, the author has included them herein after checking them against the original French version. Several typical examples of various problems are used as illustrations in order to make the methods of computation clear.
An Instrument for Indicating the Amount of Gas in Gas-Liquid Mixtures
Authors: Walsh B. R. , Peterson G. S. 
Published: December 2022

Abstract
The instrument described in this paper was developed by the authors’ company at the instigation of the Wright Aeronautical Corporation, which early foresaw the need for clarifying the entire problem of satisfactory operation of an airplane-power-plant lubrication system if the increased demands of military-airplane performance were to be met. One of the major objectives was the development of an instrument which would make possible a quantitative measurement of the amount of entrained air in lubricating oil, because air present in the oil reduces the delivery of oil from the pump; the reduction of delivery is greater the higher the altitude for the same percentage of air at the intake to the pump. This reduction of delivery may be so great as to limit the safe ceiling of the plane, from failure to lubricate the engine. All such pumps, being the positive-displacement type, can deliver only displacement minus slip; as volume of air in the pump increases, obviously, the oil delivery must decrease since the sum of air and oil handled is substantially a constant.
Elastic Properties of Plastic Materials
Authors: Delmonte John 
Published: December 2022

Abstract
Unlike most metals, the average plastic material does not have a sharp break in the stress-strain curve to denote the yield strength or elastic limit. Usually experience or even conjecture is the guide to determining working stresses. An advance toward the solution of this problem is made by the author, who describes beam-deflection methods of obtaining elastic-limit stress data which have special significance in practical applications. A curve-deviation method is also suggested by means of which elastic limits are more accurately determined than by conventional stress-strain technique.
Irreversibility in the Theoretical Regenerative Steam Cycle
Authors: Hansen R. E. 
Published: December 2022

Abstract
An irreversible process takes place in the theoretical regenerative steam cycle for power generation when superheat in the steam bled from the turbine is transferred to feedwater. Increase in entropy occurs, as in any irreversible process; this increase can be determined by a simple method of graphic integration, and used in computing additional heat rejection to the condenser. Heat rate of the cycle can then be found with a high degree of accuracy by a simple formula.
Heat Transfer From a Baffled-Finned Cylinder to Air
Authors: Lemmon A. W. , Colburn A. P. , Nottage H. B. 
Published: December 2022

Abstract
Air-cooled aircraft-engine cylinders utilize extensive finned surface to permit maintenance of proper metal temperatures with high rates of heat transfer occurring at high engine power outputs. The process of heat transfer to the flowing air stream differs from that of usual finned tubes not only in size of the cylinder but also because baffles are utilized which force all the air to pass through the fin spaces. Because of this latter difference, data on finned tubes in general do not apply. Therefore, special tests have been carried out to establish the mechanism of heat transfer in this case and to provide a generalization of the data useful for design. The work was carried out at the University of Delaware in conjunction with a Pratt & Whitney Aircraft heat-transfer research program. The experiments were conducted on a typical section of an aluminum finned cylinder barrel. The cylinder was heated by an internal electrical heater. Temperatures were measured not only of the entrance and exit air stream but also at eight points, equally spaced circumferentially, in the base metal. The results were interpreted by comparison with heat-transfer relations for flow inside conduits. The maximum heat-transfer rates were in close agreement with these relations although the average rates were lower owing to the decreased cooling-air velocities over the front and rear fin surfaces outside of the baffled portion of the cylinder. The over-all pressure drop is shown to be about double the estimated frictional resistance; the inlet and exit losses provide an explanation.
Local Coefficients of Heat Transfer for Air Flowing Around a Finned Cylinder
Authors: McAdams W. H. , Drexel R. E. , Goldey R. H. 
Published: December 2022

Abstract
This paper describes an apparatus for measuring local coefficients of heat transfer, hitherto never obtained for a jacketed or baffled-finned cylinder. The inner surface of the vertical cylinder was divided into narrow vertical segments to collect steam condensate, a measure of the local flux. Since the over-all heat balances agreed within a few per cent, local heat balances were used to calculate local air temperatures. Wall temperatures of the base of each segment were measured by calibrated thermocouples, and local coefficients of heat transfer were determined at 11 stations around one half of the cylinder. The results were easily duplicated and the condensate from the undivided side agreed closely with that from the divided side. Average surface coefficients from fins to air agreed satisfactorily with published data. For a given Reynolds number, temperature difference had no effect on the Stanton number.
Air-Cooled Steam Condensers
Authors: Bowman R. A. 
Published: December 2022

Abstract
In connection with the rehabilitation of the war-torn areas of the world, there is a great need for power plants which can be moved from one location to another without difficulty, and which can be put into operation in a short period of time. In some of the locations where these power plants must operate, cooling water will be unavailable, or obtainable only at a great premium. To take care of such cases, a number of power trains have been built to use air as a cooling medium rather than water. The trains in general have been widely described. The present paper is devoted to a more complete description of the condensers and to a report on their operation.
Heat Transfer and Pressure Loss in Small Commercial Shell-and-Finned-Tube Heat Exchangers
Authors: Armstrong R. M. 
Published: December 2022

Abstract
Preliminary results are submitted covering heat transfer and pressure loss for fluids flowing through the shells of small shell and finned-tube heat exchangers in crossflow. These results are compared to the calculated performance of similar exchangers with bare tubes, and the comparisons noted. It is brought out that this type of exchanger can now be applied to duties where finned tubes heretofore have not been used, namely, where over-all heat-transfer rates for bare-tube service would be from about 25 to 250 Btu/(hr)(sq ft)(deg F). It is also pointed out that this type unit is not suitable for many services. Actual field experiences are related.
An Electrical Geometrical Analogue for Complex Heat Flow
Authors: Kayan C. F. 
Published: December 2022

Abstract
Through the medium of the resistance concept, the general similarity of “contour maps” for heat flow and electrical flow may be visualized. The electrical analogy permits ready study of simple and complex heat-flow conditions which, because of distorted temperature conditions, would defy orthodox mathematical or graphical analysis. Internal-temperature lines (isotherms) obtained by relatively simple equipment with a geometrical type of analyzer are shown for one complex case of flow conditions.
Heat Transfer in the Locomotive Boiler
Authors: Fry Lawford H. 
Published: December 2022

Abstract
It is shown that the total heat absorption in a locomotive boiler for any assumed rate of heat release and weight of gases of combustion can be predicted with all of the accuracy practically necessary. The over-all heat transfer is considered as taking place in two separate operations which can be represented by two formulas, a fourth-power equation of the usual type for the radiation in the firebox, and a double logarithmic equation for the convection in the flues. This form of equation was suggested by Fessenden (1), and its usefulness has been extended by the coefficients developed by the present author. It may not represent the exact physical reactions of the process of heat transfer, but it has the pragmatic sanction of giving practically accurate results under many different conditions. Actually that is all that can be claimed for any other heat-transfer formula even if it uses the Reynolds number. Fessenden pointed out, “It should be noted that the apparently rational idea that the rate of heat transfer is directly proportional to the temperature difference is, after all, only an assumption that has been accepted for so long that it has come to be regarded as an axiomatic statement of fact.”
Logographs
Authors: Tour R. S. 
Published: December 2022

Abstract
A different type of chart is presented for graphical solution of equations of the form TpUqVrWs = K. The charts are called “logographs” as distinct from nomographs and depend basically on the addition of logarithms. Logograph charts develop from the fact that a straight line drawn on semilog paper represents a function of the form: log y = a + bx, or x = c + n log y. The construction of logographs is explained and exemplified in the development of a chart for the calculation of heat-transfer coefficients in turbulent flow. As examples of more elaborate logographs, charts are also offered for the turbulent flow of fluids in pipes and for the flow of fluids through sharp-edged orifices. The equations underlying the last two charts represent new forms of the standard expressions and are briefly discussed and their limitations indicated.
Circular Bulging of Aluminum-Alloy Sheet at Room and Elevated Temperatures
Authors: Sachs George , Espey George , Kasik G. B. 
Published: December 2022

Abstract
In this paper preliminary results are reported on the strength characteristics and forming limits of various aluminum-alloy sheet, when subjected to hydraulic pressure over a circular area at temperatures up to 500 F. The strain distributions were analyzed by means of a photo-grid, after these bulges failed. The bulges exhibited a practically balanced biaxial strain state over most of the contour with the exception of a very narrow range of local deformation in the vicinity of the fractures. The maximum meridional strain outside the necked area observed at the pole of a bulge, in spite of its biaxial nature, generally exceeded the uniform elongation known from tensile tests. The forming limits for all annealed conditions increased considerably with increasing temperature if the temperature exceeded a certain critical value, between 250 and 400 F, depending upon the alloy. The heat-treated conditions of the alloys 24S and 61S were only slightly affected by the testing temperature, while the forming limits (uniform stretch) of 75S-T, R301W, and R301T were materially increased at elevated temperatures. The reduction of thickness, which is a measure of the ductility of an alloy, followed approximately the same trend as the forming limit.
Coaster Gate and Handling Equipment for River Outlet Conduits in Shasta Dam
Authors: Warnock J. E. , Pound H. J. 
Published: December 2022

Abstract
At Shasta Dam, a coaster gate is used to close the intake of any one of the eighteen 102-in. conduits in the spillway section of the dam. Each conduit is provided with a control valve. The coaster gate is used to close the intake of each conduit whenever required for inspection and servicing of the control valve and conduit. It may also be used for emergency closure in the event of failure of a control valve. Since the gate design is predicated on emergency conditions of maximum head, when it is subjected to large unbalanced pressures, hydraulic model studies were conducted to determine the best shape of gate to minimize the downpull force to which it might be subjected in an emergency closing. The procedure followed in conducting the studies and the final installations are treated in this paper.
Physical Properties of Resin-Impregnated Plaster
Authors: Delmonte John 
Published: December 2022

Abstract
While development work on impregnated plaster bodies has been in progress for many years, it was not until 1945 that the process was finally commercialized with low-viscosity furane resins, and extensive applications undertaken in the tooling field, and in general improvements of plaster-of-Paris patterns and forms. The impregnation of plaster of Paris with liquid thermosetting resins and the subsequent conversion of the product with heat, result in the formation of a material which has been called “Plas-preg.” In this paper the methods of producing this material, its physical properties, and applications are discussed.
Failure of Ductile Metals in Tension
Authors: Sachs G. , Lubahn J. D. 
Published: December 2022

Abstract
The extensive fabrication of aluminum-alloy sheet in the aircraft industries has revealed the lack of fundamental knowledge regarding the phenomena which explain the performance of metals under various stress and strain states. Previous investigations appear to have neglected entirely both the effects of the part geometry and the fact that the strength of the metal and limit of forming are frequently determined by a process of instability, or “necking,” rather than by the process of fracturing. In this paper a theory of necking is developed in order to predict the forming limits for various stress or strain states based upon an analysis of the true stress-strain curve in pure tension. A criterion for necking is advanced, based upon the maximum-load (or pressure) conception of instability, and is applied to different geometrical shapes formed at room temperature. Future publications will present, in support of the criterion advanced, experimental analyses of the forming of different geometrical shapes under various loading conditions and stress and strain states.
The Necking of Tensile-Test Specimens
Authors: Lubahn J. D. 
Published: December 2022

Abstract
The conventional tensile test is the basis of acceptance tests, and its results are extensively used to evaluate the structural metals regarding their relative performance the forming and their strength in service. However, it appears that the significance of the phenomena encountered in a tensile test are little understood, in spite of a large number of investigations. In this paper, the strains encountered in long rectangular tensile-test bars of the aluminum alloys 24S-O and 24S-T have been investigated in detail. The theoretical conceptions previously advanced, regarding the necking of tensile-test bars, have been confirmed experimentally.
The Elbow Combustion Chamber
Authors: Mayers M. A. , Carter W. W. 
Published: December 2022

Abstract
A description is given of the “elbow” combustion chamber, developed for use in the gas-turbine power plant designed and built for the United States Navy by the Elliott Company. This type provides extremely high heat-release rates which is an essential characteristic for gas-turbine applications. The fuel-oil-burning system which utilizes standard Diesel fuel-injection equipment has been developed to a high point of efficiency, and may be varied over a range from full load to 1/10 full load without material change in quality of atomization. The paper discusses in detail the air-flow characteristics, fuel supply, ignition and control devices, and analyzes the combustion-chamber performance-test data.
Analysis of Special Electronic-Tube Tests
Authors: Campbell J. H. , Donsbach C. G. 
Published: December 2022

Abstract
The complexity of manufacturing electronic tubes is such that professional groups normally associated with design and laboratory activities are called upon to work in the factory. These groups contribute considerably to the control of material assembly, test, and the outgoing quality of the product. In this industry many variables exist and because none of the tube parts can be tested electrically until the tube is completed, a system of “statistical quality control” is in order. This paper illustrates improvements which may be accomplished through special tests on tubes in the course of production, followed by statistical analysis of the results.
Further Observation of Graphitization in Aluminum-Killed Carbon-Molybdenum-Steel Steam Piping
Authors: Emerson R. W. , Morrow Mathew 
Published: December 2022

Abstract
Among graphitization of steel pipe studies being carried on, the present one deals with what the authors have termed “slip-plane” graphitization, which describes a condition of graphite segregation along slip planes where local “yielding” or localized plastic deformation had previously occurred. Such graphitization has been found to vary widely from the outside to inside of a pipe and from quadrant to quadrant around the pipe periphery. It has been determined that “nodular” graphite segregation whether of the “isotherm” or slip-plane type is as effective as “chain” graphite in reducing the ductility of low-carbon or low-carbon-molybdenum steel.
The Effect of Measurement Dead Time in the Control of Certain Processes
Authors: Eckman D. P. 
Published: December 2022

Abstract
The purpose of this paper is to report on a series of automatic-control tests which demonstrate the importance of instantaneous controller-mechanism response in self-balancing potentiometer controllers. The automatic-control tests were made with both two-position and proportional-reset control. Other tests, dealing with the importance of measurement dead zone of the controller, are included, noting the relation between dead zone of measurement and dead time of controller response.