bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Exhaust Energy in Reciprocating Engines
Authors: Stumpf J. , Trump C. C.
Published: January 2024

There are a surprising number of cases where oil, gas or steam engines will show better economy than purchased power and electric motors, and this may be emphasized where the exhaust from steam engines is valuable for heating or process work. Any development which will improve the efficiency of reciprocating engines, and at the same time simplify their construction should be of interest.

Up to now, reciprocating engines have suffered from losses due to incomplete expansion. There has been a compromise between such losses and mechanical ones connected with the use of very large cylinders. Oil engines, multiple-expansion and uniflow steam engines are coming to use high ratios of expansion, and these are doing much to reduce exhaust losses. Many advantages may be gained, however, if the energy remaining in the exhaust at release can be converted into kinetic energy, and from that into partial vacuum in the cylinder. In double-acting uniflow steam engines, for instance, pistons and cylinders may be made smaller and shorter for a given load, the number of exhaust ports reduced, and a greater range of back pressures may be negotiated without extra clearance or exhaust valves. By attention to design of exhaust pipes and nozzles the performance and efficiency of such engines may be a good deal improved.

The theoretical problems are presented in this paper for discussion, and practical applications to either single-cylinder or multi-cylinder engines are suggested and illustrated.
Heat Losses From Bare and Covered Wrought-Iron Pipe at Temperatures Up to 800 Deg. Fahr.
Authors: Heilman R. H.
Published: January 2024

High-temperature superheated steam running up to 800 deg. Fahr. and high-temperature chemical processes are being more and more widely used, and accordingly the question of heat losses from pipes under such temperature conditions is one of importance to the engineering profession.

This paper presents the findings of an experimental investigation conducted in the Mellon Institute of Industrial Research of the University of Pittsburgh. The losses from bare wrought-iron pipes have been measured for temperatures up to and including 800 deg. fahr. They have been studied carefully for pipes of various diameters, and empirical formulas are presented whereby the loss from pipes of any diameter may be readily calculated.
Report Upon Efficiency Tests of a 60,000-Kw. Cross-Compound Triple-Cylinder Steam Turbine
Authors: Reynolds Herbert B. , Hovey Walter F.
Published: January 2024

The present paper contains the results of tests on the 60,000-kw. Westinghouse turbine installed at the 74th Street power station of the Interborough Rapid Transit Company, New York City.

This turbine is of the cross-compound, triple-cylinder type, consisting of one high-pressure element and two low-pressure elements, each element driving a separate generator. The normal steam pressure at the throttle is 220 lb. abs. with a superheat of 150 deg. fahr. exhausting into a vacuum of 29 in. Hg. The speed of all three elements is 1,500 r.p.m.

The primary steam inlet takes care of all loads up to 40,000-kw. A secondary inlet which bypasses the first six stages cares for all loads up to 50,000-kw., after which a tertiary inlet which bypasses the first ten stages opens and increases the capacity to 60,000-kw. The generators are able to carry a maximum load of 70,000-kw. for two hours, this being effected through a hand-operated quaternary valve which bypasses four additional stages of the high-pressure turbine.

The lowest water rate obtained while operating the complete unit under normal conditions was 11.00 lb. per kw-hr., while the highest Rankine and thermal efficiencies obtained were 76.0 per cent and 25.1 per cent., respectively. With the high-pressure and one low-pressure turbine in service the lowest water rate was 11.25 lb. per kw-hr.

Results of tests of 30,000-kw. Westinghouse cross-compound turbines at the same station were presented before the Society in 1916 in a paper by H. G. Stott and W. S. Finlay, Jr., and of 30,000-kw. General Electric turbines of the straight Curtis impulse type in a paper read at the Spring Meeting, Chicago, May, 1921, by the senior author of the present paper.
The Development and Use of the Modern Chain Grate
Authors: Marsh T. A.
Published: January 2024

After discussing the need of progressive combustion of the several constituents in coal, and the variations in grate design to handle different coals, the author takes up the improvement of chain-grate practice as regards air-tightness, cooling, size of combustion space, etc. He shows how greater boiler capacity can be obtained by increasing grate size or by more intense natural or forced draft (0.50 to 0.60 in. for a combustion rate of 40 to 45 lb. per sq. ft. of grate per hour), but states that high and sudden overloads are best met by forced-draft chain grates burning 55 to 60 lb. bituminous coal per sq. ft. per hour, with air at 2 in. pressure distributed through compartments between the runs of chain. He describes such equipment, and states that 200 per cent of rating can be reached in 8 min., from a short-banked fire, or in 52 min. from a cold grate. The paper concludes with a table of results obtained in a number of stations equipped with chain grates.
Effect of Pulsations on Flow of Gases
Authors: Judd Horace , Pheley Donal B.
Published: January 2024

The movement of gases and liquids when calculated by the existing hydraulic formulas presupposes a steady or continuous flow of the fluid. Anything which causes this flow to proceed in puffs, waves, or pulsations will result, by the action of metering devices, in errors often of great magnitude which generally do not admit of any adjustment, or of any definite knowledge of the amount of the error.

The present paper discusses work undertaken under the joint direction of the Engineering Experiment Station of the Ohio State University and the Research Sub-Committee on Fluid Meters of The American Society of Mechanical Engineers, which had for its object (a) the study of the nature of the pulsation and (b) the discovery of some practical means of reducing or eliminating the pulsation or of compensating for its effects on the devices used for measuring fluid flow. The investigation was confined to the venturi meter, the orifice meter, the flange nozzle meter, and the pitot meter, using air flow from a small compressor discharging into a 3-in. line. It is believed, however, that the basic principles established by the experiments are fundamental for pulsating-flow conditions for gas, steam, and water as well as for air, and also for other sizes and kinds of installations.
The Degasification of Boiler Feedwater
Authors: McDermet J. R.
Published: January 2024

The paper deals with the fundamental laws governing the operation of a method of degasifying water fed to boilers and economizers by heating the water to a temperature of some 25 deg. fahr. above the temperature at which it is to be deaërated and then suddenly introducing this water into a chamber in which a vacuum is maintained by a condenser and an air exhauster in series. The successful operation of the process depends upon (a) the inevitable reduction of solubility of dissolved gases in the water with increase of temperature (b) the explosive boiling caused by the rapid injection of heated water into a zone of lower boiling temperature and (c) a method of control and agitation of the water subsequent to the explosive boiling in a reduced air tension. The paper discusses the problem of eliminating air from feedwater in different types of heaters.
Hydroelectric Possibilities of Quebec
Authors: Smith Julian C.
Published: January 2024

The three watersheds of the province of Quebec have an available water-power of 5,250,000 kw. of continuous power, of which at present about 800,000 kw. have been developed and utilized, leaving available as commercial power about 4,500,000 kw. of continuous power, or 12,000,000 hp. at 50 per cent load factor. The load factor of the industries of the province range about as follows: paper mills, 65 to 75 per cent; carbide and electrochemical plants, 85 to 90 per cent; cement mills, 80 to 90 per cent; asbestos and mining industries, 45 per cent. At the present rate of increase in the use of electric power, the total available hydroelectric power in the province will be completely utilized within thirty years.
Recent Developments in Balancing Machines
Authors: Söderberg Carl Richard
Published: January 2024

In this paper the author describes a machine for balancing quickly and at low cost light rotating masses such as the rotors of small electric motors. The problems involved are discussed and the solution presented and illustrated. Four appendices are devoted to the discussion of (a) the correction of a general state of unbalance by two masses, (b) the requirements for constant period of a balancing machine with a movable fulcrum, (c) the analysis of the vibrating motion, and (d) the sensitiveness of the balancing machine.
A Steam–Loss Prevention Plan Operating in a Textile–Finishing Plant
Authors: Burke Henry Morgan
Published: January 2024

The author gives details of simple and elastic methods installed in the power department of a large textile-finishing concern, which made it possible to diagnose daily plant operation, introduce new operating practices, enthuse the personnel with the importance of their tasks, keep accurate records, and effect important economies in the generation, distribution, and utilization of steam and power.
Reheating in Central Stations
Authors: Wohlenberg W. J.
Published: January 2024

In this paper the author discusses the influence of amounts of energy added in reheating, number of reheating stages, and points in expansion at which reheating should begin. A comparison is made of reheating, regenerative, and combination cycles combining both reheating and bleeding stages, and it is shown that, because of the influence on the internal machine efficiency thereby, reheating properly applied may lead to higher efficiencies than bleeding. It is furthermore shown that the combination cycles give promise of realization in practice of appreciably higher efficiencies than would be the case for the other cycles investigated. The analysis also indicates that for a limiting steam temperature of 750 deg. fahr., the maximum efficiency is attained at initial pressures varying between 600 and 900 lb., the exact optimum depending upon cycle, fuel, and steam generator used; and that if pressures are increased beyond these points there will result an actual reduction in overall efficiency.
Measurement of Management
Authors: Roe Joseph W.
Published: January 2024

In this paper the author discusses the need of measurement and the characteristics necessary in any method of measuring management, and outlines a method for comparing managerial performance in different plants or variations thereof in a single plant.
The Protection of Steam-Turbine Disk Wheels From Axial Vibration
Authors: Campbell Wilfred
Published: January 2024

One of the most important features in the design and manufacture of a steam turbine is the elimination of the possibility of vibration occurring at the various natural frequencies of its disk wheels and buckets. This paper describes an investigation by the General Electric Company of various forms of vibrations and waves which may exist in steam-turbine disk wheels. The dangerous critical speeds that must be guarded against are discussed, together with other minor resonant conditions that it is advisable to avoid. The testing machines used for verification of predicted frequencies and critical speeds are described in detail as well as the different types of tests made. The conclusion gives the procedure, necessary in all cases, for the definite protection of steam-turbine bucket wheels from axial vibration, as justified by several years of successful manufacture.
Available Data on the Properties of Irons and Steels at Various Temperatures
Authors: French H. J. , Tucker W. A.
Published: January 2024

The authors point out that while a vast amount of test work has been carried out on the properties of ferrous metals at high and low temperatures, the information available is incomplete and unsatisfactory. They summarize effectively the information available for temperature effects on such mechanical properties as tensile strength, elongation, hardness, strength in torsion and crushing for cast irons, steels, cast steels, and malleable iron. There is invariably a loss in mechanical properties with increase in temperature, but this varies for each metal and alloy. The importance of the time factor in all tests is emphasized and short-time tests are considered as worthless by some investigators in indicating true behaviors under service conditions.

A brief note is given regarding the thermal expansion of some metals, some alloys, such as invar and the related nickel steels, departing completely from the usual laws of thermal expansion. “Growth” in cast iron with repeated heating is considered, and “semi-steel” is recommended for use in annealing ovens, rolls, fire bars and other cases where repeated heating occurs.

Chemical inertness is shown to be an important factor in the selection of metals for use at high temperatures, some alloys being more resistant to chemical change than others. Oxidation of steels is briefly studied. While it is evident that all steels weaken with considerable rise in temperature, the composition and treatment of steels may be varied to meet specific requirements, and emphasis is laid on the fact that heat-resisting alloys which are now being produced commercially have very desirable properties at very high temperatures. Many of these alloys cannot be called steels or even ferrous alloys, and in some cases are practically free from iron, but they are extremely valuable, nevertheless. Nickel-chrome-iron base alloys and copper-nickel and other non-ferrous alloys are among those shown to be promising for heat-resisting purposes. There is also a possibility of the development of coated metals for high-temperature service. Aluminum and chromium coatings are particularly promising in this regard.
A Review of Recent Applications of Powdered Coal to Steam Boilers
Authors: Kreisinger Henry
Published: January 2024

This paper gives a brief statement of the trend of the development for the past two years of the application of powdered coal as a fuel for making steam. It includes treatment of developments in furnaces, driers, and mills. Test results are given from boilers and mills in six central stations using pulverized coal as fuel. The author also discusses mill capacities for various grades of coal.
Recent Developments in the Burning of Anthracite
Authors: Shoudy W. A. , Denny R. C.
Published: January 2024

The anthracite referred to is that of which at least 95 per cent will pass through a 3/16-in. round-mesh screen and less than 20 per cent through a 3/32-in. round-mesh screen. The coal was burned on Coxe stokers.

The paper describes successive furnace designs made at the Amsterdam (N. Y.) steam station of the Adirondack Power and Light Corporation. The boilers are of Babcock & Wilcox design and of 1345 hp. Each boiler has two Coxe stokers. Attempts were made to improve on the customary furnace design to which the following objections are made: (a) tendency to stratification of gases, (b) high carbon content of ash, (c) loss of fines to ashpit and stack, and (d) lack of flexibility.

The first experimental furnace had, in addition to the ignition arch, a very short arch over the rear of the grate. With this arrangement improvement, if any, was slight. A three-arch furnace was then built, with better results but with defects due to slagging. A third furnace of two-arch design was finally constructed. Tests reported in the paper show that with the final design stratification can be practically eliminated, as well as ignition troubles, even with low-grade coal. A decided improvement has also been made in the burning of undersizes. Greater capacity was obtained with low-grade coal (60 per cent undersize and 33 per cent ash) in the multiple-arch furnace, where 300 per cent of rating was easily reached, than in the single-arch furnace where 190 per cent was about the limit. The boilers and furnaces are described and illustrated, and a description of the tests with the principal data and results are given in the form of curves.
Design, Manufacture and Production Control of a Standard Machine
Authors: Flanders Ralph E.
Published: January 2024

The paper describes the methods by which difficulties in manufacture and production control were avoided by the Jones and Lamson Machine Company. The company having passed through a period of increasing speeds and feeds, improvements in methods of doing work and controlling it, with satisfactory results as to total machinery time and direct labor cost, directed its attention to overhead which had suffered a considerable increase due to foremen, clerical work, cost and production offices necessary for the methods which had been adopted.

Reorganization commenced with a segregation of the products in manufacture so that separate manufacturing organizations and equipments were provided for each product, i. e., the Hartness flat turret lathe, the Fay automatic lathe, and the Hartness opening die; while a fourth organization was established for repair and special work. A redesign of the product was then undertaken to eliminate as many parts as possible and to standardize parts to fit several types of machines. The shop was arranged on a basis of departments by products. The author describes the turret-lathe shop and the chief manufacturing processes involved.

The routing and stock-room control are described by the author. Each order is nominally for two months’ production. Rough- and finished-parts stock rooms are kept supplied with half-lots in reserve to prevent hold up in production, but there is no stock-keeper assigned to them. Standard routing is made up from previous experience reckoning on 80 per cent theoretical machine capacity. With bi-monthly starting dates, both rough and finished stock get a complete count six times a year, and adjustments of volume of production are easily made.

Under the present system the foreman has full power within his territory and can measure the efficiency of his department by the schedule of hours for a given rate of output. There is little need for cost accounting, cost of machines being determined on overall operation of the shop, costs of material, labor, overhead and fixed charges being divided by output. An hourly rate basis is used for wage payment.

In a recapitulation, the author points out the following principles: Standardization of product; a separate manufacturing equipment and organization for the product; departmentalization by product rather than by process; a recurrent production schedule; concentration of plant; minimized transportation; disturbing and difficult factors confined to purchasing; visual control of work itself instead of remote control by records; control by orders instead of by records; automatic control of inventories; cost figuring by analyzing total rather than by totaling innumerable details; a plain job for every man and full responsibility with it.
An Investigation of the Critical Bearing Pressures Causing Rupture in Lubricating-Oil Films
Authors: Linsley Leonard Noel
Published: January 2024

The problem involved in the paper is to determine the critical or breakdown pressure in the oil films formed in a bearing, using straight mineral oils and also to determine the influence on this critical pressure of the admixture of definite amounts of oleic acid. The author first presents a résumé of the work of other investigators. He describes the apparatus with which his own experiments were conducted and the characteristics of the oils used in his tests. Tests were run with cast-iron and with babbitt bearings, and the results of the final trials, which were run with two of the oils, first untreated and later treated with oleic acid, are given in tabular and graphic form. Efforts to determine the breakdown pressure electrically and the method of measuring film thickness are described. The paper concludes with suggestions for the extension of the experimental work and the redesign of the test apparatus.

In discussing his conclusions the author remarks that the actual breakdown pressures of oils are several hundred times greater than have hitherto been accepted as possible. Although not definitely established, a relationship between breakdown pressure, speed, and viscosity was shown to exist. The actual breakdown pressures at which the film is completely dislodged and the bearing seizes the journal should not be considered as the critical pressure but rather the point at which metallic contact first makes itself manifest. With reference to oils treated with oleic acid the inference cannot be avoided that oils having the same absolute viscosity but differing in chemical consistency do not have the same resistance to rupture and hence, from this point, differ in lubricating value.
The Value of Efficiency in Transforming and Distributing Energy
Authors: Lucke Charles E.
Published: January 2024

Realizing that cheaper heat and cheaper power are closely related national problems requiring engineering methods for their solution, the author in this paper gives valuable data to serve as a guide for the efficient transformation and distribution of energy. Costs of primary energy at the source, transportation or transmission costs, and costs at point of use are presented in tables and charts. Methods and costs for the preparation of a suitable working fluid for the generation of water and steam power are given, and the transformation of working-fluid energy into brake-horsepower energy is shown by means of numerous tables. Other tables give hydroelectric, steam-turbine, and Diesel oil-engine power costs. The paper concludes with an interesting summation of total costs and a comparison of economies of small and large stations.
A Code of Design for Mechanical Springs
Authors: Wood Joseph Kaye
Published: January 2024

This paper first gives an entirely new derivation of the general spring formulas developed by the author from the numerous scattered orthodox spring formulas and presented in his paper on Mechanical Springs at the A.S.M.E. Annual Meeting in December, 1924. The two sets of formulas, although derived independently, are identical in fabrication of terms, and since the new derivation is based upon the direct application of the individual terms, this agreement establishes the general formulas on a more logical and practical basis. There are some differences, however, in the specific values of the stress-method and form-of-section constants, which in the case of springs of the uniform-flexure type account exactly for differences which have been found between calculated and actual test results. Complete research is urged to confirm this finding definitely, and until such work is done the author will employ the constants that agree with the orthodox formulas. In view of the remarkable manner in which the new derivation establishes the logical arrangement of the generalized formulas, the author has drawn up and included in the paper a brief code of design for mechanical springs, which he hopes will serve as a nucleus for a more complete and final code in the future.
Steel-Foundry Management
Authors: Bull R. A.
Published: January 2024

The author discusses those steel-foundry problems that in his opinion have the greatest general significance in this highly specialized branch of manufacture. He presents a brief analysis of the industry, explaining its technical and commercial divisions, and the significance of each from the standpoint of output, for the purpose of more clearly indicating the nature of the industry under consideration.

Many occupations in the steel foundry are listed in order to explain the complex nature of the operations for which a manager is responsible. The branches of a company organization are assigned to staff and line departments. Reasons are given for certain classifications, regarding which procedures occasionally vary. Policies governing staff departments are discussed separately, not for the purpose of enumerating all duties ordinarily performed, but with the intention of provoking discussion regarding certain factors considered by the author to be of fundamental importance, about which there are differences of opinion.

The subject of compensation both for workmen and for foremen is emphasized because the author believes this is a detail of management which is of very great significance.
Lake Waters for Condensers
Authors: Christie A. G.
Published: January 2024

The paper points out the persistence of stratification of warm- and cold-water layers in our northern lakes and other deep waters. The cold bottom layers make excellent cooling-water supplies for condensers and would permit operation at high vacuum throughout the whole year. The savings from increased vacuum are such that engineers should give this factor careful consideration, both in the selection of plant site and in the design of intakes, particularly for large power stations. Temperature-depth studies of the particular lake should be made to furnish exact data upon which a rational decision can be based.
The Rational Design of Covering for Pipes Carrying Steam up to 800 Deg. Fahr.
Authors: Carter W. A. , Cope E. T.
Published: January 2024

The authors present an analysis of the problem of determining the most economical thickness of pipe covering for steam pipes carrying steam of a total temperature of 500 deg. fahr. and at higher temperatures up to 800 deg. fahr. based on the work of Heilman, Eberle, and others. Two cases are considered, first, in which the total steam temperature is 500 deg. fahr. and a single covering material is used; second, in which the total steam temperature is 700 deg. fahr. and a compound covering, made up of a layer of higher temperature-resisting material next to the pipe and a layer of lower heat-resisting material over it. Curves showing the method of determining the most economical thickness of covering for a 6-in. pipe carrying steam at 500 deg. fahr. and 700 deg. fahr. are included. Equations for the calculations involved are included and the procedure of making the calculations is explained. Three appendices deal with some of the assumptions made in the analysis.
Basis for Determining the Proportions of Standard T-Slots and Bolts
Authors: Burlingame Luther D.
Published: January 2024

For many years forward-looking engineers have urged the standardization of the holding elements of machine tools, such as T-bolts and slots. The importance of such standardization, has been generally recognized, not only by individual manufacturers but by the National Machine Tool Builders’ Association, the technical societies, and the American Engineering Standards Committee. This has resulted in the appointment of a sub-committee which for several years has been at work on the problem of providing an acceptable standard for T-slots such as are used in the tables of machine tools. A standard has now been formulated by the committee and is the subject matter of a report presented at this meeting.

A great amount of material has been collected showing past and existing practice. Tests have been conducted to ascertain the comparative strength of bolts and slots, in order that the proportions submitted might be suited to practical needs. That the report of the committee may not be loaded with the records of this investigation but instead may be concentrated on the actual proportions to be adopted that report is supplemented by this record of the underlying investigations on which it is based.
The Development of Tap-Drill Sizes
Authors: Danekind A. C.
Published: January 2024

Charts for tap-drill sizes as a rule are made up from the opinions of operators, without basic knowledge of the factors governing the selection of the proper tap drill. Different groups of operators in the same plant will develop different charts for the same set of conditions. The author has studied various existing charts and has devised one that takes into consideration the character of material being tapped, the bearing of thread desired, the thickness of the tapped section, and other essential factors.
The Termination of Charcoal Tests for Gasoline
Authors: Kallam F. L.
Published: January 2024

One of the most important features of testing natural gas for gasoline content by means of activated charcoal is the knowledge of when to terminate the test. This paper deals with a method by which the maximum gasoline content may be determined without danger of under- or over-saturating the charcoal when even the approximate content of the gas is unknown. It points out that the correct termination point is determined from the temperature rises and falls in the charcoal due to the adsorption and displacements of the various hydrocarbons. The modifying effect of the condensing phase of the problem is also discussed and conclusions drawn.
A Short Method of Calculating the Periodic Displacement and Oscillations in Synchronous Machines
Authors: Cutler C. W.
Published: January 2024

The paper forms a basis for the design of flywheels for engine-driven generators operating in parallel. The present rules, simple enough for commercial design, apply only in the case of operation against an infinite system. The present paper therefore develops a method whereby the power exchange, torque variations, and other phenomena can be accurately obtained with practically no greater effort than with the present approximate rule. The general solution for two engine-driven generators by means of a nomographic chart is given in an appendix which also explains the method of constructing the chart.
Tests and Theory of Curved Beams
Authors: Winslow A. M. , Edmonds R. H. G.
Published: January 2024

Despite the fact that curved beams comprise such important machine elements as crane hooks and punch frames, previous laboratory tests have been, in general, of meager scope and uncertain interpretation. The laws of stress distribution, therefore, are subject to diverse opinions among prominent engineers. The present tests consist of strain-gage observations at several points throughout the cross-sections of large steel specimens, determining complete strain curves. Radial strains, apparently not previously investigated, are definitely measured and a simple working theory of radial stress is developed. Stress in a radial direction is shown to be a vital factor in the design of curved beams of certain proportions. Finally, different theories of circumferential stress are investigated, both by comparison with tests and by analysis; prominent fallacies are pointed out and a more logical fundamental hypothesis advanced in support of the theory adopted.
Heat Transmission From Condensing Steam to Water in Surface Condensers and Feedwater Heaters
Authors: McAdams W. H. , Sherwood T. K. , Turner R. L.
Published: January 2024

New experimental data are presented for single-tube water heaters supplied with exhaust steam. These, together with various data from the literature, are analyzed by the graphical method of E. E. Wilson, by means of which the overall resistance to heat transfer, 1/U, may be successfully resolved into its component parts. Furthermore, by employing a coefficient of 2000 for the steam side, and by using the equation of McAdams and Frost for the water-side coefficient, it is possible to predict the value of U for various water velocities and temperatures. These predicted values compare closely with published test data, both for vacuum condensers and feedwater heaters operated with exhaust steam, covering a range of sizes from 80 to 50,000 sq. ft. For abnormal amounts of air or scale, proper allowances should be made by applying the resistance concept.

The equation previously published for the heat transfer on the water side is found to be satisfactory for vacuum condensers and exhaust heaters. However, in analyzing laboratory data for single-tube apparatus heated by steam materially above atmospheric pressure, it was found that this equation gave unduly conservative results, the discrepancy increasing with increase in steam pressure. This may be due to the boiling of the water on the inner wall of the pipe, to the evolution of dissolved air, etc. Fortunately, since commercial tubular apparatus are usually operated either under vacuum or with exhaust steam, this complication is of minor importance in plant practice.
An Introduction to the Problem of Wing Flutter
Authors: Greene Carl F.
Published: January 2024

After defining wing flutter and analyzing the evidence accumulated as to the conditions under which it occurs, the author gives particulars of a study of the torsional oscillations of an airfoil, and of the position of the elastic axis and location of the center of mass of an airplane wing. He then discusses the aerodynamic considerations involved in the problem and the present status of the latter, and concludes with a brief discussion of the field of future investigation. The purpose of the paper is not to present any general solution for the problem, but to promote discussion as to rational methods of employing such data as are now or may be on hand with a view to formulating a sound basis for future design procedure.
The Design of Commercial Airplanes
Authors: Short Mac
Published: January 2024

Commercial airplane design, according to the author, had its inception in the three-place OX-engined plane. From a crude beginning in 1919 and with but little encouragement it has developed to a point where large production is demanded as well as many refinements, and along with this has come a universal awakening to the importance of commercial aviation in the nation’s business. Intensive production methods are not as yet entirely applicable to the machines at present manufactured in quantity, but nevertheless have possibilities. Permissible expenditures to save a pound in weight amount to from one to two dollars. There is a constantly increasing demand for better performance, greater useful load, artistry of appointment, and comfort in the evolution from the open-cockpit to the enclosed airplane.
Some Economic Features Affecting Commercial Aviation
Authors: Trube Carl E.
Published: January 2024

This paper is a discussion of the value of speed in saving transportation time, the ideal and most desired range of airplanes, the earning abilities of different airplanes operating at different airport-to-airport scheduled speeds, and the influence of power, size, and scheduled speed of airplanes on the profit-making possibilities of a passenger-transport enterprise.
The Range and Severity of Torsional Vibration in Diesel Engines
Authors: Porter Frederic P.
Published: January 2024

This paper gives a general treatment of the subject of the torsional vibration of irregular shafts. It is illustrated by examples of computations for the shafting of certain Diesel-engine installations that have been investigated.

The material presented is the result of a study to determine accurately the range of vibrations and the speeds at which they occur. The data also give the results of a study on the effect of elastic hysteresis and other damping forces in determining the maximum vibration at the various critical speeds.
Investigation of Insulated Walls: Thermal Properties of Different Materials and Built-Up Wall Sections Discussed as Applied to Cold-Storage Work and Houses in Severe Climates
Authors: Rowley Frank B.
Published: January 2024

This paper gives some of the research work at the University of Minnesota on the thermal properties of insulating materials and built-up wall sections for the type of construction used for houses in cold climates and for cold-storage work. A description of the types of test apparatus used is followed by a discussion of the results. A method is shown for converting from one set of results to another. The effect of moisture and temperature on the thermal conductivity of the materials is shown by test results. A group of walls tested by the hot-box method is given, showing in detail their construction and insulating value.
Factors Governing the Purchase of Coal
Authors: Smith Morgan B.
Published: January 2024

In this paper it is pointed out that plant efficiency can be raised only by coordinating coal selection, better plant operation, betterment and proper maintenance of plant, adequate records of plant performance, and installation of instruments for the guidance of plant operators and for obtaining comparative operating data. Coal selection is probably the most important single factor because only through proper selection can coal best suited to existing plant equipment be bought. Entering into the problem of coal selection are details of the boiler plant, the coal available, the coal mine, the vendor of the coal, a method of checking the quality of the coal delivered, method of delivery, the purchase order or contract, price arrangements, specifications, and contracts. Several contract forms appear in the paper, and suggestions for the study of coalmining districts and individual mines are given.
High-Pressure Steam Boilers: A Study of the Principles Underlying Their Design and Construction
Authors: Orrok Geo. A.
Published: January 2024

After briefly referring to the work of Münzinger, Hartmann, and Mellanby and Kerr, the author proceeds to discuss the lines of further investigation which to him seem to offer the most promise. In so doing he discusses the effect of tube inclination; the circulation problem; releasing surface and steam space; safety in operation; increase in capacity; boiler materials; temperature margins; and stresses in superheater tubes, riveted drums, and headers. Among other things, it is brought out by this discussion that (1) a high-pressure boiler must consist largely of banks of tubes; (2) that headers in great variety are available up to at least 1400 lb. pressure; (3) that drums must be of small diameter and should not contain over 10 per cent of the water content of the boiler; (4) that below 1000 lb. there is no need of employing alloy steels, but above that pressure such steels are available and should be used if the temperature margins so require; (5) that for superheats higher than 800 deg., alloy steels are indicated; (6) that 20 or more different designs of boilers are successfully operating at pressures of 500 lb. and over, six at 1000 lb., and one at 2000 and over; and (7) that enough work has been done to show that their efficiencies are comparable to those obtained with boilers of lower pressure. In closing, the author states his conclusions as to the type of high-pressure boiler best suited to present limitations.
Modernization of the Industrial Power Plant
Authors: Spencer C. G.
Published: January 2024

In this paper the author discusses modern practice as applied to the industrial power plant. He compares the progress in this branch of the power-generation field with that in central-station practice, and also shows how the engineer may by studying his plant improve conditions with a reasonable expenditure of money and produce results comparable with those to be expected from service purchased from a modern central station. The various steps to be taken in this program of modernization are touched upon and some of the lately rebuilt plants embodying the suggested improvements are described and illustrated.
Stresses and Reactions in Expansion Pipe Bends
Authors: Wahl A. M.
Published: January 2024

In this paper methods are outlined for the determination of stresses and reactions in pipe bends, in accordance with exact theory which takes into account pipe cross-section distortion. Formulas for various types of bends are given. The computation of maximum transverse and shearing stresses in accordance with the exact theory is facilitated by means of curves which are given. The theoretical results for deflection and distortion of the pipe cross-section are verified by tests made on small pipe bends at the Westinghouse Research Laboratory. Application of the theory to practical cases is illustrated, while the effect of steam pressure on the amount of flattening is shown to be small.
Fineness of Pulverized Fuel as Affected by Mill Types
Authors: Work Lincoln T.
Published: January 2024

Fineness of pulverized coal is increasingly important for small combustion space, as with Scotch marine, high-pressure, or small industrial boilers. The amounts of sieve size affect the completeness of combustion with correspondingly higher boiler efficiency and less smoke, while the amounts of superfine material affect the ease of combustion and the rate of radiation.

This investigation shows that the various principles of mill action make fuels of different fineness. The hammer mills produce relatively coarse coal with but little superfines, the roller mills produce widely differing fineness depending upon specific mill action and upon plant conditions, and the tube mills normally produce coal low in sieve mesh and high in superfines.

Air-classifying schemes are shown to vary greatly, there being room for much development with most mills. The author’s turbidimetric method for measuring superfines is described.
Boiler-Furnace Refractories: This Group of Materials Includes Brick and Tile, and Also the Wall Mortars, Plastic Compounds and So-Called High-Temperature Cements
Authors: Hirshfeld C. F. , Carter W. A.
Published: January 2024

A field survey of the conditions to which refractories were subjected in different kinds of service was made along with laboratory investigation such as analyses of fuel and petrographic study of new and used refractories. The work had as its object the determination of the chemical and physical phenomena occurring in boiler-furnace refractories to work out data to aid in choice of firebrick for specific purposes. Each type of furnace construction, each method of firing, each variety of fuel, and each set of operating conditions calls for an unique solution.
The Economic Status of Oil as a Fuel for Marine Service: It Is the Ideal Combustible, but Is Not Capable of Universal Adoption, Especially Where Net Operating Costs Are a First Consideration
Authors: Richardson George Atwell
Published: January 2024

There have been no developments in oil-burning equipment for two or three years. Reasonable furnace efficiencies have been reached, and no great incentive exists for improving equipment. What has been accomplished has been in furnace design. Despite its advantages, oil is not capable of universal adoption from an economic standpoint.
Progress in Central-Station Use of Pulverized Coal: Summary of Experiences at Cahokia and Analysis of Their Meaning From the Standpoints of Performance and of Dollar Value
Authors: Tenney E. H.
Published: January 2024

Operating records of five pulverized-fuel-firing arrangements and furnace designs show what value lies in each, these depending upon the grade and price of coal used, the plant load factor, and the rate for fixed charges. The design best adapted shows a saving of $0.40 per ton of coal in operating costs and a saving of $2.44 in fixed charges, having been brought about by reduction in coal-preparation costs, general improvement in boiler economy, reduction in furnace maintenance by the use of water walls, elimination of hard slag in furnace by horizontal firing, and increase in ratings by the use of water walls, turbulent firing, and draft equipment. The nature of further improvements will be difficult to forecast. Improvement of mills will probably depend upon development of new types and on present designs, in maintaining the fineness of grind, and greater facility for repairs. The problem of higher rates of heat liberation in the furnace is receiving attention. Water walls have about reached their limit with practically the entire furnace enclosed. The use of radiant superheaters as a part of furnace walls offers possibilities in obtaining a higher and more even superheat. Means for reducing the quantity of fly ash in the flue gases will be important where pollution of air is a severe local disadvantage. All these problems can be discussed to the greatest advantage if considered from a completely economical viewpoint.
Present Status of Furnace and Burner Design for the Use of Pulverized Fuel: Both Are Being Intensively Improved, and Now That Water-Cooled Furnaces Are Being Well Designed, Their Shape and Size and Wall Construction Can Be Made to Suit the Burning Equipment
Authors: Bailey E. G.
Published: January 2024

The ideal burner is one by which combustion of fuel can be accomplished in a furnace of minimum volume and with reasonably low excess air. The differences between the problems of burning oil and gas and pulverized coal are of relative magnitude rather than of principle, and hence the improvements in pulverized-fuel burners are following the lead of the gas and oil burners by having all the air for combustion enter with and adjacent to the fuel at the burner with active turbulence and mixing. Pulverized coal is still more difficult to burn than oil.
Friction in Dredge Pipes
Authors: Polhemus James H. , DuPriest John R.
Published: January 2024

This paper presents some information on pipe friction for dredge pipe 29 in. inside diameter and with velocities up to about 20 ft. per sec. The data were obtained during some recent tests of large hydraulic dredge pumps, and on account of the large size of the pipe and the high velocities encountered it was thought worth while to present the information for the benefit of others engaged in dredge work.

An analysis is also given of the data showing how the equation for loss of head in pipe lines can be modified so as to give a constant friction factor as velocity varies instead of having both velocity and friction factor vary in the equation.
Physical Properties of Alloy Steels Under Various Heat Treatments and at Elevated Temperatures
Authors: Callomon C. B.
Published: January 2024

The author confines his treatment to two of the newer and less well-known ferrous alloys: (1) so-called “stainless” iron, a steel containing from 12 to 16 per cent of chromium and less than 0.12 per cent carbon; and a “super” stainless iron containing from 12 to 20 per cent of chromium and 7 to 10 per cent of nickel. The former not only resists corrosion but is readily machinable; it is susceptible to heat treatment, under which it attains remarkable physical properties fitting it for a wide range of engineering applications. The second alloy, the strength of which is increased by hot or cold wording rather than by heat treatment, resists corrosion much better than the first one, but is more difficult to form and machine. Further, it is from 7 to 15 per cent lighter than other corrosion-resisting metals and alloys. Both alloys have high tensile strength at elevated temperatures; the latter being the better in this respect, however, having an ultimate tensile strength of 25,500 lb. at 1650 deg. fahr.
Recent Developments in the Use of Nickel Steels
Authors: McKnight Charles
Published: January 2024

After recounting the early uses of nickel steel for armor plate, guns, and projectiles, the author deals at some length with the development of its use in locomotive construction for heavy forgings and later for the shell plates of high-pressure locomotive boilers. He then touches briefly on three recently developed iron-nickel alloys—Invar, Permalloy, and Nickeloy—the latter two being employed extensively in electrical work, and with the substitution of nickelchrome-steel castings for those of manganese steel in trackwork.. He concludes with a statement of the advantageous properties conferred on cast iron by the addition of nickel.