High-pressure Boilers Research Articles

Experience With Instruments and Control Equipment for 2000-Psi Boiler at Somerset Station of Montaup Electric Company

Abstract This paper presents comprehensive descriptions and operating experiences with the instruments and control equipment as applied to the high-pressure high-capacity boiler of the Somerset Station. Details are given not only of the completely automatic operating and control equipment but also of the indicating and recording instruments which enable the operators to follow constantly the operating conditions of the boiler and thus permit immediate manual adjustment when the need is indicated.

Special Studies of the Feedwater-Steam System of the 2000-Psi Boiler at Somerset Station of Montaup Electric Company

Abstract In conjunction with other studies on the high-pressure forced-circulation boiler at the Somerset Station of the Montaup Electric Company during the past 3 years, tests to determine, particularly, the extent of dissolution of iron throughout the system, and the formation of high-iron sludges were made. A summary of the findings of this investigation are given in this paper.

Water Conditioning for the 2000-Psi Boiler at the Somerset Station of Montaup Electric Company

Abstract Considerable interest has been aroused in the chemical treatment used for the high-pressure boiler at the Somerset Station of the Montaup Electric Company. The theoretical aspects of the present treatment, which has been in use since January 1, 1944, are given in a paper by Hall. Details of the results obtained with the different types of treatment used on this boiler have been given in a paper by Parks. It is largely the purpose of this paper to present the reasons for the various methods of chemical treatment which have been used, and for the changes made, which have resulted in stabilization of the boiler-water conditioning since January 1, 1944.

Expanded tube joints in boiler drums, with special reference to the battersea high-pressure boilers

Particulars are given of the major pressure parts of two high-pressure boilers installed at Battersea Power Station, each comprising four alloy steel drums and their interconnecting mild steel tubing. Their design and working conditions are described, and a historical review is presented of their erection and of problems which arose whilst rendering the expanded tube joints leakproof. The gradual resolution of these problems is then traced through several stages. It was realized that the leakage was fundamentally due to the elastic strain which occurs in the tube holes of highly stressed drums, which, at Battersea, amounts to about twice that pertaining to mild steel drums. The holding power of the joint is thus relaxed to an abnormal extent, sufficient to permit leakage. The elastic deflexions, or total “spring” of the joint, resulting from the expanding operation, must therefore be correspondingly increased to accommodate the increased drum strain.Various suggested methods of achieving this are reviewed...

The 1939 Callendar Steam Tables

THE successful design of improved steam power-cycles utilizing high pressures and temperatures depends entirely on an accurate knowledge of the properties of steam. An increase in the efficiency of the steam cycle by 1 per cent represents a large annual saving in the coal cost for a modern power station; but this degree of accuracy in the calculations can only be attained if the tabulated properties of steam at extended pressures and temperatures are reliable. Practical evidence was obtained of the inaccuracy at high pressures of the earlier steam tables when high-pressure boilers were first constructed, for the calculated heat transferred to steam plus the measured losses in the boiler was greater than the heat supplied by the fuel. Since the losses in a modern boiler are small, and can he measured with a high degree of accuracy, it was clear that the tabulated total heats of steam were greater than the true values. The 1939 Callendar Steam Tables Compiled and edited by G. S. Callendar A. C. Egerton. (Published for the British Electrical and Allied Industries Research Association.) Second edition, with New Appendix on Properties of Compressed Liquid Water. Pp. 70. (London: Edward Arnold and Co., 1944.) 12s. 6d. net.

Experience With Sodium and Potassium Chemicals for Boiler-Water Conditioning at Montaup Electric

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.

A New Approach to the Problem of Conditioning Water for Steam Generation

Abstract Modern boilers, because of their high operating pressures and ratings, and their high rates of heat adsorption, intensify the problems associated with the continuous operation which is of such critical importance in our vast productive program. For instance, actual consumption of the boiler tubes by the high-pressure boiler water must be continuously guarded against. Destructive boiler scale such as that composed of sodium silicate, sodium-aluminum and sodium-iron silicates, sodium sulphate and sodium phosphate, must not be permitted to form. The boilers must not fill up with sludge, and the turbines must be kept free of deposits on their intricate blading. Suspecting that sodium for a number of reasons is of destructive influence in the boiler water, the author has initiated building boiler waters on a potassium basis, with affirmative results that are set forth in this paper. Starting with substitution in the boiler water of potassium for the universal sodium equilibrium, the author has been led to give consideration to the problems of “hide-out” of boiler-water salts, corrosion by the bonded oxygen of the boiler water, silica in boiler and turbine, equilibria developed in the superheater in any carry-over of boiler water, and under certain conditions, protection from embrittlement. In systematizing the results which must ensue from the complex network of interrelations of temperature, pressure, and concentration, under these conditions, he makes use of the conceptions of the concentrating-film boiler water, generalizes the temperature-pressure-concentration relations in the form of a Δt function, and points out how the relationship of incongruent solubility between water and the silicates must be controlled.

Theory of the Expanding of Boiler and Condenser Tube Joints Through Rolling

Abstract Tubes in industrial water heaters, steam boilers, and condensers of turbines are fitted in the holes of adjoining drums or head plates by expanding the tube ends. These are slightly enlarged by means of small revolving rolls. In one large steam condenser many thousands of such tube joints have to be rolled, and in high-pressure boilers these joints must remain tight under several thousands of pounds pressure at high temperatures. The investigation reported in this paper, of the conditions under which tube joints are expanded and made pressure-tight, was undertaken at the suggestion of R. A. Bowman, manager of condenser engineering, of the South Philadelphia Works of the Westinghouse Electric and Manufacturing Company, early in 1942. The pressure of the revolving rolls creates a radial plastic distribution of stress in the tube wall and around the hole in the adjoining heavy steel plate. After the tube end has been rolled, a system of residual stresses remains locked up near the joints which is essential for its pressure tightness. These plastic states of stress have been investigated for various types of the stress-strain characteristics of the tube metal and steel of the head plates. Simple rules are used for computing the stresses in a moderately thick-walled tube under external and internal pressure, either in the elastic or in the plastic state of stress.

Silica Removal by an Improved Magnesia Process

Abstract Modern high-pressure boilers with high feedwater make-up requirements frequently demand reduction of dissolved silica. A new magnesia process for silica removal has been developed, combining flexibility, simplicity, and economy. It can be applied to any type of water at any temperature; it can be carried out in conjunction with the usual precipitation water-softening process; and the increase in operating cost is very small. These results are accomplished by a new method of combining a number of principles embodied in this process. Extensive investigations were conducted to determine the influence of each of various factors on the final result, and data are presented on the effects of the following: Form of magnesium used (whether precipitated ionic Mg or undissolved Mg compound), temperature, sludge-magnesium concentration, and agitation for sludge-water contact. The principles of increasing the Mg++ content, when required, by means of a novel sludge recycling process with a magnesium dissolver are described. A method of using cheap dolomitic lime as a low-cost source of magnesium is also presented. The process lends itself advantageously to a modified Spaulding precipitator type of construction at either low or high temperature, to be followed by suitable treatment with carbonaceous-ion exchangers, when required, for complete removal of residual hardness and reduction of alkalinity to any predetermined figure.

Silica in High-Pressure-Boiler Water

Abstract The advent of high steam pressure has resulted in many boiler-tube failures in which silica appears to have played a very significant part. Attention is called in this paper to the fact that silica trouble appears to be more prevalent in high-pressure boilers having high rates of heat input. Trouble has occurred irrespective of high or low silica content in the boiler water, although silica scale does not form in all boilers irrespective of the amount present. The author points out the need for more basic knowledge regarding the behavior of silica in boiler water at high pressures and temperatures, as well as the development of satisfactory methods for determining the form in which silica exists in the boiler water.

A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces

Abstract This paper is devoted to a discussion of the elements of boiler and furnace design dealing with the problem of obtaining adequate circulation for the higher pressures now demanded by current practice. After explaining the action within a simple evaporating circuit, the author indicates the procedure in analyzing waterwall circuits and calculating the circulation in boiler tubes.

Discussion: “A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces” (Van Brunt, John, 1941, Trans. ASME, 63, pp. 339–343)

Discussion: “A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces” (Van Brunt, John, 1941, Trans. ASME, 63, pp. 339–343)

Discussion: “A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces” (Van Brunt, John, 1941, Trans. ASME, 63, pp. 339–343)

Discussion: “A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces” (Van Brunt, John, 1941, Trans. ASME, 63, pp. 339–343)

Discussion: “A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces” (Van Brunt, John, 1941, Trans. ASME, 63, pp. 339–343)

Discussion: “A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces” (Van Brunt, John, 1941, Trans. ASME, 63, pp. 339–343)

Discussion: “A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces” (Van Brunt, John, 1941, Trans. ASME, 63, pp. 339–343)

Discussion: “A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces” (Van Brunt, John, 1941, Trans. ASME, 63, pp. 339–343)

Closure to “Discussions of ‘A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces’” (1941, Trans. ASME, 63, pp. 343–347)

Closure to “Discussions of ‘A Study of Circulation in High-Pressure Boilers and Water-Cooled Furnaces’” (1941, Trans. ASME, 63, pp. 343–347)

Superheat Control and Steam Purity in High-Pressure Boilers

Abstract The author discusses the problem of designing a high-pressure boiler to deliver steam at high temperatures. The problem becomes more difficult as the capacity increases since proper selection and maintenance of boiler materials, design of the separate boiler and furnace units, and maintenance of the latter becomes increasingly more difficult if superheat control and steam purity are to be maintained. The author analyzes these design features and points out the compromises necessary to meet varying operating conditions. He discusses superheater design, maintenance of heat-absorbing surfaces, boiler circulation, relation of furnace-exit temperatures to slagging and boiler performance, and safe metal temperatures in water-walls and superheaters.

Mechanical Purification of Steam Within the Boiler Drum

Abstract The paper is a report of tests run on new high-pressure high-temperature boiler installations to determine a baffle arrangement for the steam drums that would prevent objectionable carry-over during normal operation. The arrangements of three types of baffle are illustrated and the results are given in tables and graphs as conductivity measurements on condensed steam samples taken from eight different points in the drum. The cyclone-separator baffle finally developed will deliver steam containing solids approximating 0.5 ppm with boiler-water concentrations up to 1600 ppm, and will permit a large range of load change and water-level variation.

Discussion: “The Behavior of Sodium Sulphite in High-Pressure Steam Boilers” (Hitchens, R. M., and Purssell, Jr., J. W., 1938, Trans. ASME, 60, pp. 469–473)

Discussion: “The Behavior of Sodium Sulphite in High-Pressure Steam Boilers” (Hitchens, R. M., and Purssell, Jr., J. W., 1938, Trans. ASME, 60, pp. 469–473)

Closure to “Discussions of ‘The Behavior of Sodium Sulphite in High-Pressure Steam Boilers’” (1939, Trans. ASME, 61, p. 269)

Closure to “Discussions of ‘The Behavior of Sodium Sulphite in High-Pressure Steam Boilers’” (1939, Trans. ASME, 61, p. 269)