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A detector with a wire mass transfer was modified for the analysis of thermally labile halogen derivatives of tetrahydrofurans. The wire and eluate enter a combustion oven directly and the combustion products are carried by a tream of air into a double-burner alkali flame ionization sensing element.

A formula is obtained for computing the evaporation constants for water and ethyl alcohol in high-temperature gaseous media. The computed evaporation constants are compared with experimental values.

ABS>An increase in coal production and consumption is necessary if the U. S. is to gain energy self-sufficiency. The clearing of an array of environmental, technical, social, and economic factors is necessary to improve production records. Oil and natural gas replaced coal following World War II and there was much speculation that nuclear power was the long-term energy source, so a great lag developed in coal research. Electric power is produced overwhelmingly from coal combustion, and with the passage of the Clean Air Act of 1970, it appeared that standards for sulfur emiasion control could not be met by the 1974 deadline. Stack scrubbers are expensive and considered to be unreliable. Synthetic; fuels production from coal is expensive. Labor relations in expanding coal production is discussed. (MCW)

An analysis of the limestone scrubbing process for SO/sub 2/ removal was carried out. It was found that low concentrations of SO/sub 2/ in power plart flue gas (

The author proposes a method for classifying the various factors influencing the life safety hazard posed during fires. Five fire hazard components are identified as oxygen deficiency, toxic combustion products, smoke particulates, hot gases, and flame exposure.

This note examines the validity of the mean beam length technique, which is an approximate engineering method for calculating radiative heat transfer in furnace gases. Exact and mean beam length results are compared for laminar flow of carbon monoxide between parallel black surfaces. The results show that the mean beam length calculations overestimate the heat transfer by 47 per cent. This approximation gives better results than other approximate techniques used such as the gray gas and optically thin approximations. Further work is needed to determine the validity of the mean beam length technique in more complicated geometries, and when gas mixtures are present.

A computer solution of chemical equilibrium composition is presented for high-temperature combustion reactions related to fireside corrosion and ash fouling. A simple calculation system, which models the injection of a sodium-potassium mixture through a flame, is solved for equilibrium compositions at temperatures from 1500 deg to 3000 deg F at varying oxygen levels from 0.1 percent to 17 percent in the gas stream and 1 atmosphere pressure. At equilibrium, principally alkali sulfates and hydroxides are produced in the model of a combustion product atmosphere resembling that in a coal-fired boiler. A total of 42 reactions involving 40 chemical species were treated in the reactant mixture and compositions for the entire system are included.

Buoyancy production rates for a pure heat source and for a fire heat source of burning woody fuels show that fire may be regarded as a pure source yielding heated air rather than heated combustion products.

The generation of a spherical detonation was verified experimentally by two coalescing deflagration waves. Numerical results of treating the three different types of deflagration of detonation transition with Hugoniot curves are in full agreement with our experimental observations.

A method is described for the microdetermination of carbon and hydrogen in fluoro and perfluoro compounds. Samples are burned in a rapid flow of oxygen (35 ml/min) using the rapid straight empty tube method. Carbon and hydrogen are determined by gravimetry. Before entering the soda asbestos tube, the combustion products are conducted through a silica gel-hydrochloric acid mixture and then either through acidified silver nitrate solution or through silica gel transfused with silver nitrate. The standard deviation ranges from ±0.03 to 0.38 for carbon and from ±0.04 to 0.25 for hydrogen.

Effect on protective coatings of launch pads of exhaust products, chamber pressure, nozzle diameter, etc, from aluminized solid propellant rocket motors

In 1967, Messrs, Wagoner and Duzy presented a paper at the Winter Annual Meeting of the ASME entitled “Burning Profiles for Solid Fuels”, in which they described a derivative thermogravimetric procedure for evaluating the burning characteristics of coal and similar materials. Since that time, others, including Esso Research and Engineering Company, have attempted to duplicate this test in their own laboratories with varying degrees of success. The present paper describes some of the precautions required in setting up the test in other laboratories and gives further information on details of the test procedure which must be followed to obtain comparable results. Burning profiles of three chars obtained from the U. S. Bureau of Mines and of several petroleum cokes are also included.

Refinements concerning dissociation effects and temperature dependence of specific heats have been introduced to improve the traditional theoretical analysis of homogeneous two-stage combustors in which the maximum heat release is limited by chemical kinetics. The use of the traditional ‘fuel availability factor’ was abandoned and attention was centred on improving the determination of the ‘fraction of a specie converted to combustion products’. These refinements lead to results which are different from those published previously. The improved analysis presented yields significant new findings. Among these are: (1) specific heat release can be increased by a factor of almost two over that of an equi-volume combustor by allotting the total available volume to the high temperature reaction, and adding excess air only as the products leave the reaction zone, and (2) secondary stage operating conditions are determined by the volume of the two stages and the total molar flow rate. Thus, the multiple operating points indicated by other authors do not, in fact, occur.

THE HISTORY of this subject may conveniently be divided into three phases: first, the early work which led to the discovery that ethylene had some influence on the rate of ripening of fruits and vegetables; second, the finding that plant tissue apparently gives off some gas or vapor which affects the ripening of fruits; and last, the identification of this active substance. Forced curing of citrus fruits was practiced in California, and the early use of a tent and a few kerosene stoves in the field was considered ample to provide the "heat" necessary for stimulation of the coloring of the fruit. After sad experience had shown that steam heat was not so effective as the " crude " earlier arrangement, Sievers and True (1912) demonstrated that the coloration in forced curing was brought about primarily by the gaseous combustion products of the kerosene stoves. Chace and Denny (1924) and Denny (1924) proved by a series of experiments that the effective constituent among these gases was readily absorbed by bromine and had a specific gravity approximately equal to that of air. These facts suggested that the active gas might be ethylene, and further work proved ethylene to be very effective in bringing about the desired change in the color of the fruit. Since then Denny (1924), Harvey (1925), Chace and Church (1927), Regeimbal and Harvey (1927), Mack (1927), Regeimbal, Vacha, and Harvey (1927), Hibbard (1932), Dufrenoy (1929), Kohman (1931), Wolfe (1931), Rosa (1928), Ramsay and Musso (1930), Fudge (1930), Davis and Church (1931), Marloth (1933), and Dustman (1934) have reported the effects of ethylene upon the ripening of various plant products. The experience of the United Fruit Company in the carrving of bananas from the tropics to this country may have parallels in commercial handling of fruits, though none has been published. Over a period of years prior to 1917, it was noticed that some bananas ripened faster than the bulk of the shipment during transportation. It was further noted that this ripening generally occurred in pockets. Moreover, there was a tendency for a "ripe pocket" to act as a focus of ripening for a whole bin of bananas. Evidence accumulated which pointed to the fact that this pocket ripening was not entirely caused by heat, and it seemed that some other factor helped to induce this phenomenon. The theory developed that the carbon dioxide evolved by the fruit during respiration was influential in the production of " ripes " in pockets. Though this was soon discredited, there seemed to be some correlation between the respiration rate and accelerated ripening.

Although methyl and ethyl hydroperoxides alone do not react with potassium permanganate in acid solution at room temperature, they can be oxidised by this reagent in the presence of hydrogen peroxide. The apparent equivalents (as compared with hydrogen peroxide) are much lower than usual but, in the presence of excess hydrogen peroxide, the titre due to the organic peroxide is proportional to its original concentration. This forms the basis of a simple titration method which, though empirical, is both rapid and accurate. Since t-butyl hydroperoxide does not react in this way, it may be possible to differentiate the higher peroxides from lower peroxides.

Several aspects of bluff body flame stabilization are discussed in terms of a theory which focuses attention on the initial mixing region between cool combustible and hot combustion products. Some experiments by Broman and Zukoski on flame stabilization in a “deflected jet” are correlated in terms of the theory. The “characteristic time” of Zukoski and Marble is shown to arise as a special case of the theory. The extinction of the propagating flame as the initial event in the blowoff process is discussed qualitatively in terms of the theory. Finally, the results of experiments reported in the literature on injection of gas into the recirculation zone are rationalized in terms of the theory.

Trace quantities of the polynuclear hydrocarbons have been identified in flue gases resulting from combustion or carbonaceous fuels. Some of these hydrocarbons, particularly benzo(a)pyrene, possess known carcinogenic properties and are of some concern in the overall assessment of the effects of atmospheric pollution. An investigation was carried out under a two-year grant received from the U. S. Public Health Service to determine the occurrence of polynuclear hydrocarbons in the flue gases from various coal-fired steam-generating installations. The paper describes the preliminary work leading to the development of satisfactory sampling and analytical procedures and gives the results obtained from sampling various field installations.

In the trucking section of South Philadelphia the air is often heavily loaded with combustion products from great industrial plants, railroad engines, and other sources. The soils of this region, consisting of Sassafras loam, are somewhat acid but not more so than another area of the same soil type at Monmouth Junction, New Jersey, where there is little smoke. Other sandy soils, of DeKalb areas, have shown approximately the same PH values. The geographical distribution of acidity in South Philadelphia apparently is not correlated with the location of the smoke producing plants. With better cultural methods, cultivated lands in another type of soil have been kept near neutrality

A small out-put industrial diesel engine was used and the conditions of its piston-rings were changed, for the study of phenomena on the piston-ring leakage. And the following conclusions were obtained mainly : (1) Leakage occurs at three passages which are the clearance spaces at the lower, outer side and gap of the ring. And the rates of leakage through each passage are nearly equal when these passages are of the similiar shape and size. (2) Angle and step joint cannot reduce the increase of the leakage as same as straight joint when the gap is enlarged. (3) When rings of the good and bad tightness are used together, the good ring only makes the gas-tight. (4) the greater part of the gas that leakes out is air, and it is believed that the harmfully incomplete combustion products are caused by combustion of the oils on the gas passages. (5) For reducing the specific fuel consumption, a smaller number of rings of good-tightness must be used.

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The conditions for the estimation of peroxides by three established, methods have been re-examined in detail. 1. It is shown that the reduction of organic hydroperoxides by stannous chloride (barnard and hargrave method) can be carried out quantitatively and rapidly in alkaline solution. The advantages of this modification are discussed. 2. The exact conditions are described for accurately measuring the concentrations of hydrogen peroxide and of the lower organic peroxides by the thiocyanate method. Amyl alcohol is recommended as a decolourizer for the reagent since the red colour produced by the action of the peroxides is stabilized, permitting accurate spectrophotometric measurements, Using this reagent, 0.03 micrograms of peroxide per ml can be estimated. 3. The limits of the titanous sulphate method of estimating hydrogen peroxide have been determined and a method suitable for the determination of 0.3 micrograms of hydrogen peroxide per ml is described.

A literature survey is presented on the effect of pressure on soot formation in flames For continuous flames the main effect is an increase in soot formed proportional to pn where 1 < n < 3. However the reverse is true for gaseous explosions, as the soot yield decreases with pressure, presumably because the combustion products have a greater chance to approach equilibrium. Diffusion flames show a low pressure limit below which soot does not occur, while for premixed flames the critical fuel/air ratio for soot formation is found to be essentially independent of pressure, although the proportion of tarry materials may vary.

The phenomenon of corrosion is so extensive that it is universally accepted as an inherent part of our present‐day commercial and industrial life. It is not surprising, therefore, to find corrosion problems associated with the most important of our chemical processes, the combustion of fuels. All our industrial fuels contain inorganic constituents, and during the combustion process certain of the more volatile constituents may be released in an active form to contaminate the combustion products.

Noise field from ground testing of nuclear rocket engines operated at various reactor power levels

A research problem on the control of the temperature, using pulverized coal as a fuel for intermittent kilns. The paper consists of a description of the operation and design of a fire box with a hot-spot combustion chamber for the ignition of the fuel during the water-smoking period, and first part of the oxidation period.

Droplets of clouds on a mountain and of fog in an urban area were captured and the form, nature and size of their nuclei were studied by means of an electron-microscope and by a chamber of constant humidity. These nuclei have similar form and nature to the hygroscopic particles in haze and to the artificially produced combustion particles. No sea-salt nuclei were found in our observations, therefore sea-spray appears to be an insignificant source of condensation nuclei. It was found that both the cloud and the fog nuclei originated in combustion products which were the mixture of hygroscopic and non-hygroscopic substances, and that the greater part of the nuclei did not contain pure sulfuric acid. DOI: 10.1111/j.2153-3490.1952.tb01008.x

The closed-flask combustion products of some nitrogen compounds were studied. The percentage of nitrogen oxides formed (expressed as nitrate-nitrogen) was determined. Combustion of these samples, after mixing with inorganic oxidants, in a stream of oxygen was also investigated. Trials for the application of the oxygen-flask method for the microdetermination and detection of nitrogen in many organic compounds are reported.

This paper is concerned with the determination of the spectral absorptivities Kω and emissivities ɛ of a thermodynamic-equilibrium mixture of combustion products consisting of CO2, H2O, CO, OH, HCl, HF, H2, and NO molecules on the temperature interval 2000–5000° K. The proposed calculation method, based on the use of a graph of the molecular absorptivities reduced to atmospheric pressure, enables Kω and ɛ to be calculated for any gas mixture composed of the above-mentioned molecules.

We examine the settling out of the additives K2CO3 and K2SO4 from a stream of combustion products onto a laterally streamlined tube. Experimental data are given and the unique features of the process are discussed.

Pressurization with nitrogen has been studied as a technique for suppressing fires in confined spaces. Liquid hydrocarbon-air fires of various sizes in a gastight experimental chamber were extinguished in approximately 30 seconds by increasing the total pressure of the enclosure from l atm. to 1.35 ± 0.03 atm. The post-fire atmospheres were found to contain sufficient oxygen for support of normal human activity, while the buildup of hazardous combustion products was well below established safety levels.

This paper describes original work on the reactions of sulfur with oxygen in flame systems of H2S-O2-Ar, where the stabilized thin flame was microprobed and the quenched products of reaction were examined with a mass spectrometer. Problems in identifying reaction products are described. Although the mass spectrometer was shown capable of checking wet analyses for mixtures of gases, the composition of combustion products was not determinable accurately by this method. Preliminary kinetic data are presented for both, homogeneously and heterogeneously (catalytically) produced SO2 and SO3.

Raw coal is still burnt as fuel in many developing countries. These also have a lot of waste biomass, which finds limited use or used inefficiently. Besides pollution from coal and biomass combustion, they always face problems during transportation and storage because they are susceptible to moisture. Biobriquettes are composite fuel prepared from a mixture of biomass and coal in a roller press briquetting machine. They consist of different proportions of biomass (up to 30%) and coal or lignite (up to 70%). Introduction of lime based desulfurizing agents (DSA) such as CaCO3 and Ca (OH)2 into the briquettes can reduce the SO2 emissions by 80-90%, thus minimizing the pollution coming from coal combustion. Some fuel and combustion properties of these briquettes were studied. The briquette fuels have better physico-mechanical properties and combustion properties in comparison to coal/lignite. The ignition temperatures of biobriquettes are lower than coal or lignite, whereas the calorific values are greater than biomass. Hence, the biobriquettes can be used as an alternative fuel to fuel wood, coal and lignite in the kilns, boilers, combustors and for cooking as well.Key words: Coal; Biomass; Biobriquettes; Desulfurizing agents; Ignition temperatureDOI: 10.3126/njst.v10i0.2944 Nepal Journal of Science and Technology Vol. 10, 2009 Page: 121-127

Combustion of coal by gasification-transformation of coal into gas prior to combustion in a furnace-is an advantageous method of combustion especially for smoke-removal in cities and for utilization of low-quality coal, and can be applied for boilers, gas turbines and industrial furnaces. Gas producers for this purpose must have improved efficiencies and high capacities. Construction and test results of a continuously operating gas producer, which was test-built to verify this method, are described and it is shown that this producer can be operated at a gasification efficiency (hot gas base) 94% for a long period by employing an improved injection method of air and steam. And, experimental results and technical problems about combustion of low-quality coal by gasification method are also discussed.

The local combustion efficiency and the local heat release rate in an upright cylindrical combustion chamber having a diameter of 100 mm and a length of about 1000 mm, were experimentally determined from the contents of combustion products. The burnt gases sampled from ten positions in the combustion chamber were analyzed with gaschromatograph. The experiments were carried out under the following conditions : Initial mean diameter of atomized fuel=40∼140 microns, air excess ratio=0.8∼1.6 Oil for a jet engine (JP-4) whose chemical compositions were known, was used as a fuel. In addition, the local combustion efficiency and the local temperature of burnt gas were determined theoretically and compared with experimental results. The theoretical results were in good agreement with experimental ones.

Analyses for porphyrins in the lunar samples were carried out by extracting the lunar soils as received by organic solvents followed by analytical demetallation using methanesulfonic acid after which free-base porphyrins, if present, were recovered and demonstrably recomplexed with divalent cations. Samples from Apollo 11 showed the presence of fluorescent substances attributed to exhaust from the descent engine. One sample from Apollo 12 showed pigments resembling porphyrins. The Apollo 14 results were negative.