Evaporators employed in the distillation of sea water have scale form on their heat transfer surfaces as calcium carbonate, magnesium hydroxide, and calcium sulfate in 300 to 500 hours of operation. Although the measures directed to overcome the formation of scale in sea water evaporators have been varied, none of these measures have been as successful as desired, and the problem is, therefore, still a major one. In 1947, however, C. A. Hempel, Armour Research Foundation, Chicago, Ill., approached the scale problem of sea water evaporators rationally by saying that if the carbon dioxide content and the pH of sea water could be controlled by either physical or chemical means, that the scale deposition on the heat transfer surfaces would be reduced. By experimentation, Hampel developed a process whereby sea water is heated under pressure for a definite period of time, and then it is released to atmospheric pressure with aeration. This physical pretreatment process removes the carbon dioxide that is evolved from the decomposition and hydrolysis of the carbonate and bicarbonate content of sea water, and thus prevents the formation of insoluble calcium carbonate. The change in alkalinity does, however, cause insoluble magnesium hydroxide to form, but this insoluble material can be readily removed by filtration followed by acidification. Therefore, two of the scale forming salts, calcium carbonate and magnesium hydroxide, have been eliminated by this process. In 1948, both the U. S. Coast Guard and the Bureau of Ships, Navy Department, became interested in this development of Hampel's, and they agreed to design a pretreatment plant for a 4000-gallon per day evaporator in order to evaluate further this process on a large scale basis. Such a plant was designed and constructed at the Norfolk Naval Shipyard, Portsmouth, Va., with the Coast Guard providing the necessary materials and equipment for the pretreatment plant, and the Navy furnishing the materials and equipment for the distilling unit. The Army Engineer's building and sea water facilities that were available at Fort Story, Va., made it a highly desirable location for the testing of the decarbonation and distilling units. So, after all the equipment had been fabricated and hydrostatically tested, it was shipped to Distillation Test Station at Fort Story where it was erected and made operational by Naval Shipyard personnel. In September, 1949, a series of tests were started on this equipment at Fort Story to evaluate the design and construction of the pretreatment plant to decarbonate sea water es a means of reducing the scale in a 4000-gallon per day Grissom-Russell low pressure, double effect Soloshell evaporator. The first test of decarbonation calibration was made to determine the optimum operating conditions of the pretreatment plant which would give the maximum degree of carbon dioxide removal from sea water. The second test was a blank determination of evaporator scale, using untreated feed, by which a comparison could be made with all subsequent tests. The pretreatment plant involved the operation of two pieces of equipment, the feedwater holding tank and the aerator tank. The procedure that was followed in this calibration was essentially this: the sea water was heated to a definite temperature at a specific feed rate, pumped to the feedwater holding tank and retained in this tank for definite periods of time; then the sea water was released to the aerator tank, again held for definite periods of time while being aerated with air, and a sample of sea water analyzed to determine the degree of carbon dioxide that was removed by these conditions. The variables that had their effect on the degree of decarbonation were, therefore, feed temperature, feed rate, feedwater tank holding time, aerator tank holding time, and air rate. The effect of temperature on the degree of decarbonation was that the greater the temperature, the greater the carbon dioxide removal; 250 °F removed 47.5 to 50 per cent, 240 °F removed 38 to 42 per cent, and 228 °F removed 25.2 to 25.8 per cent. The effect of feed rate at 250 °F on the degree of decarbonation was that the smaller feed rate, the greater the carbon dioxide removal; a feed rate of 5.25 gallons per minute removed 42.1 to 52.4 per cent whereas a feed rate of 10.5 gallons per minute only removed 36.6 to 47 per cent. The effect of feedwater tank holding time on the degree of decarbonation et 250 °F and 5.25 gallons per minute feed was negligible since holding times of 25, 45, 66, 86, and 106 minutes removed 50.2 to 54 per cent of the carbon dioxide. In the determination of the effect of aerator holding time on the degree of decarbonation a 250 °F and 5.25 gallons per minute feed, the greater the holding time, at 14 and 28 minutes, the greater the carbon dioxide removal, i.e., 46 end 50 per cent, respectively. The effect of air on the degree of decarbonation at 250 °F, 5.25 gallons per minute feed, and 28 minutes aerator tank holding time, was that it gave the greater degree of carbon dioxide removal, but without air, the effect was that the greater the feedwater tank holding time, the less the carbon dioxide removal. The difference between the two air rates tried was negligible; 5 cubic feet per minute removed 51 to 54 per cent, whereas 20 cubic feet per minute only removed 44 to 52 per cent. With no air, however, a feedwater tank holding time of 25 minutes removed 50.8 per cent, 45 minutes removed 43.5 per cent, 66 minutes removed 39.5 per cent, and 106 minutes removed 38.5 per cent. Therefore, from the results of the calibration, it is concluded that the optimum operating conditions for the pretreatment plant are a feed temperature of 250 °F, a feed rate of 5.25 gallons per minute, a feedwater tank holding time of 25 minutes, an aerator tank holding time of 28 minutes, and an air rate of 5 cubic feet per minute which will remove 50.8 per cent of the carbon dioxide in the sea water. In the blank determination, the feed by-passed the pretreatment plant and went directly to the evaporator, which was operated at a feed rate of 5 gallons per minute, 150 °F, 2.5 pounds per square inch, gage of steam to the first effect, 97 pounds per square inch, gage of steam to the air ejector, 26.5 inches of vacuum, 70 gallons per minute of circulating water, and 1.5-thirty seconds overboard brine density. In 135 hours of operation, 19,400 gallons of fresh water were produced which had a salinity of less than 0.5 grain per gallon. Scale was formed at a rate of 0.23 pound per 1000 gallons of distillate produced, and whose composition wan 91.1 per cent calcium carbonate, 2.6 per cent magnesium hydroxide, 2.7 per cent calcium sulfate hemihydrate, 2.7 per cent silica dioxide, and 1.1 per cent ferric oxide. From the operation of these tests, it is concluded that both the pretreatment plant and the distilling unit operated satisfactorily within the limits of their design. / Master of Science

In 1947, while working on the aromatic cyclodehydration of ketones to their corresponding substituted anthracenes, Vingiello (1a) attempted to prepare 9-cyclohexylanthracene using this method. It was evident in the cyclization of o-benzylcyelohexyl-phenone (I) that the hydrol (II) postulated as an intermediate could lose water in two ways, yielding two different compounds 9,10-dihydro-9-cyclohexenylanthracene (IV) and 9-cyclohexyl-anthracene (III). This is shown in Chart I. Since a carbon, hydrogen analysis gives the same result for both compounds it is obvious that some other method of identification is necessary. It is the purpose of this part of the investigation to attempt to identify the existing structure by ultra-violet absorption analysis, and formation of derivatives and also to attempt to prepare 9-cyclohexylanthracene by an unequivocal method. / Master of Science

The problem of supplying fresh water to meet the requirements for normal operation of ocean-going vessels has been of major importance for centuries in maritime circles. An early solution of this problem was the storing of fresh water on the vessel while in port for use white at sea. This solution was not satisfactory because it meant added tonnage and lost storage space. The present approach in the production of fresh water from salt water by distillation. The distillation of sea water to produce fresh enter has been widely used in maritime circles throughout the world, but in spite of its wide adoption there are still matters existing that have not been settled. The most troublesome of these is the formation of scale on the heating surfaces of the distillation equipment. These scale deposits are caused by the precipitation of the solid matter in the sea water during the distillation process. As a result of the scale, the efficiency of the equipment is reduced and the production of fresh water is thereby diminished. Much attention has been given to the elimination of scale deposits in sea water distilling apparatus. Chemical pretreatments, which had been successful in preventing scale in evaporators using ground waters, were tried on sea water equipment but no completely satisfactory processing has been found. Mechanical and chemical methods of scale removal are now being used, but these methods offer no solution to the scale formation problem. A possible solution has been offered by the Armour Research Foundation of Chicago, Illinois. Basing their theory on the fact that the scale deposits formed are composed primarily of carbonates, the Armour Research Foundation has worked out, on a small laboratory scale, a heart-aeration process that eliminates the carbonates from the sea water before it enters the distilling plant. The process is divided into three separate steps. The first step, the removal of carbonates, is accomplished by heating the seat water to a temperature above 200 °F, holding the water at this condition for a period of time, and then aerating the water with compressed air. This step removes part of the carbonates present, but in the process magnesium hydroxide is precipitated. The second step, the removal of the precipitated magnesium hydroxide, is accomplished by filtering the decarbonated sea water. The third step, the neutralization of the high alkalinity resulting from decarbonation, is accomplished by injecting sulfuric acid into the sea water before it is fed to the evaporator. The sea water fed to the evaporator after this treatment is neutral and partially free of carbonates. The use of this treated sea water should greatly reduce the formation of scale in the evaporator. A treatment and distillation plant has been erected at the Distillation Test Station, Fort Story, Virginia. Evaluation of the Armour Research Foundation process for the prevention of scale was made with the use of this equipment. The specific purpose of this investigation is to evaluate the complete decarbonation-filtration-acidification process for scale prevention on sea water distillation equipment. / Master of Science

Master of Science

Before the method of moment and thrust distribution can be applied to trussed bents, certain constants must be determined. These constants can be obtained without too much difficulty as has been shown. Once these bent constants are known, the moment and thrust distribution may then be performed about an equivalent joint. For Fink type trussed bents the location of this equivalent joint is dependent upon either of two assumptions which make use of the Spagnuolo column and the Maugh equivalent column. The actual process of the distribution of the thrusts and moments follows the pattern developed by Professor Cross. Care must be taken however in carrying out the procedure to be certain of including all the effects that accompany the balancing process. / Master of Science

The usage of the coal is very extensive. For each particular process, there is always a better method to burn some kinds of coals than the others. Each application of the combustion of coal is an individual problem. This problem involves not only the single factor of burning of coal but also the factors of the economy, materials, and manufacture. An efficient burning process is not always the suitable one to be used. On some practical field of coal combustion the testing, or trial method serves very satisfactorily for finding the best firing method. The boiler and furnace testing method applied in the steam power plant is an excellent example. However, there is an important thing in common in all the coal firing processes which is the burning of coal. An understanding of the fundamental characteristics of the coal burning is obviously very helpful to the practical usages, especially to the design of a new process. / Master of Science

The failure of the Tacoma Narrows Bridge in November 1940 was a major course of the beginning of research on the Aerodynamic Stability of Suspension Bridges. Wind has wrecked suspension bridges for over a century but the underlying cause, an increasing harmonic amplitude due to wind, has been ignored until recently. For many years bridges have been designed to withstand horizontal wind pressure, but the lift force and the overturning moment due to wind have been overlooked. This investigation, in part, was conducted so that aerodynamic coefficients of certain bridge sections not heretofore investigated could be determined. With data from these tests engineers can determine beforehand whether the sections, if used, will be safe against uplifting, sliding, overturning, and of building up oscillations of catastrophic proportions. The second part of this thesis is devoted to the determination of the torsional oscillation effects in order to predict the dynamic wind characteristics of bridge sections. The dynamic tests are necessary to verify the analytical predictions obtained from the static tests and are valuable in obtaining the aerodynamic constants necessary for the complete solution of the bridge analysis. / Master of Science

The strength of 102 wood box columns of air-dry dense select southern pine was investigated in order to determine formulas for their design. Constructional variables such as column slenderness; plank thickness, fastening, and arrangement; and the use of spacers for individual plank stiffening were studied as to their effects on column strength. The analysis shows that those formulas currently used for the design of other column types are suitable for box column design if properly modified. Short box columns develop (1) a strength equal to that of solid columns of equal slenderness if of 2-in. Lumber and (20 85 percent of the solid column load if of 1-in. Lumber. The Euler formulas for long columns and the constant (K) in the fourth-power Forest Products Laboratory formula for intermediate columns must be revised to account for the load capacity of long box columns which is less than that of equivalent solid columns as a result of the lower stiffness of a nailed cross-section. The incorporation of box columns rather than solid columns in timber frameworks results in savings of material. Furthermore, with standard lumber sizes a wider variety of cross-sectional areas for box columns can be built than is possible with standard timber sizes for solid columns. / Master of Science

Master of Science

The use of distillation for converting sea water to non-saline water has a history dating back over 400 years. This problem has been especially troublesome in regard to the installation of evaporator units on shipboard, in which operation costs, steam consumption, and space requirements are critical. The major difficulty in the operation of the evaporators has been the deposition of an insulating scale composed of calcium sulfate, calcium carbonate, and magnesium hydroxide on the heat transfer surfaces of the evaporators. Various chemical and mechanical treatments have been successfully used by industry to prevent scale formation in fresh water distilling plants but these processes have not proved successfully used by industry to prevent scale formation in fresh water distilling plants but these processes have not proved successful when applied to salt water evaporators. A possible process for preventing scale formation in salt water evaporators has been proposed bt Armour Research Foundation whereby the carbon dioxide gas present in the sea water either as dissolved gas or combined in the form of carbonate and bicarbonate ions can be removed by heating the feed water to a temperature above 200°F, holding it at this temperature for at least 30 minutes and aerating the feed using compressed air. After about 50 percent of the carbon dioxide has been removed, the feed becomes saturated with magnesium hydroxide. The precipitate can be removed from the feed water by filtration, and the high alkalinity of the saturated solution can be reduced by injecting sufficient sulfuric acid into the feed water to the evaporator. Laboratory tests can indicate that feed water treated in this manner will not deposit calcium carbonate or magnesium hydroxide scale on the heat transfer surfaces of the evaporator. Full scale operational tests of this process are to be conducted at the Army Engineering Research and Development Laboratory, Distillation Test Station, Fort Story, Virginia. The purpose of this investigation is to determine the effect of decarbonation-filtration feed treatment of sea water in reducing scale formation in a 4,000-gallon per day, double effect, low pressure, Solo-shell evaporator. / Master of Science