scholarly journals The pressure of explosions.—Experiments on solid and gaseous explosives

1905 ◽  
Vol 76 (513) ◽  
pp. 492-494 ◽  
Keyword(s):  
High Pressures ◽  
Maximum Pressure ◽  
Gaseous Mixtures ◽  
Coal Gas ◽  
Gaseous Products ◽  
Solid Explosives ◽  
Rate Of Cooling

Although this subject has been dealt with by numerous investigators, certain branches of it still remain practically untouched. With regard to the solid explosives used in ballistic work, the maximum pressure developed is usually well known, but the conditions which govern the combustion of the charge and the rate of cooling of the gaseous products require further investigation. Explosive gaseous mixtures have only been studied at initial pressures but little above that of the atmosphere. Even in the case of coal-gas and air, which forms an exception to this rule, the work has not been extended to high pressures. The present research was undertaken with a view to filling in these gaps.

scholarly journals On radiation in a gaseous Explosion

1910 ◽  
Vol 84 (569) ◽  
pp. 155-172 ◽  
Keyword(s):  
Heat Loss ◽  
Radiant Energy ◽  
British Association ◽  
Maximum Pressure ◽  
Closed Vessel ◽  
Coal Gas ◽  
Hot Gas ◽  
Quantitative Results ◽  
Rate Of Cooling ◽  
The Difference

In the first report of the British Association Committee on Gaseous Explosions, attention was drawn to the probable importance of radiation in determining the rate of cooling of the mass of hot gas produced by igniting an inflammable mixture in a closed vessel. In the second report reference was made to some experiments which I had made on the effect of coating the walls of the explosion vessel with bright tin-foil. It was found that if a mixture of coal-gas and air of given composition were exploded in a vessel thus lined, the maximum pressure reached was nearly the same as that given by an identical mixture when the tin-foil lining was blackened, but the rate of cooling was decidedly less. Though the experiment established a substantial difference between the rates of heat-loss in the two cases, it was hardly sufficient to justify giving quantitative results, nor was it absolutely conclusive as to the cause of the difference, though it seemed highly probable that it was due to the difference in the power of the walls to absorb radiant energy.

The Bakerian Lecture. On the composition and analysis of the inflammable gaseous compounds resulting from the destructive distillation of coal and oil, with some remarks on their relative heating and illuminating powers

1833 ◽  
Vol 2 ◽  
pp. 119-121
Keyword(s):  
Specific Gravity ◽  
High Temperatures ◽  
Carbonic Acid ◽  
Gaseous Mixtures ◽  
Coal Gas ◽  
Gaseous Products ◽  
Secondary Formation ◽  
Artificial Illumination ◽  
Mutual Action ◽  
Sulphuretted Hydrogen

This paper is divided into two sections: in the first, the author’s object is to show that no other compound of carbon and hydrogen can be demonstrated to exist except that usually termed olefiant gas , consisting of one proportion of carbon and one of hydrogen; and that the supposed compound of one of carbon and two of hydrogen, generally called light hydrocarbonate , is in reality a mere mixture of hydrogen and olefiant gases. In proof of this opinion he details a series of analytical experiments upon the gases from coal, oil, acetate of potash, moist charcoal, &c., conducted chiefly by detonation with oxygen, by heat alone, and by the action of sulphur at high temperatures, and obtains results analogous to those afforded by mixtures of hydrogen and olefiant gas, of the same specific gravities. Of the gases above-mentioned, however, the specific gravity, combustibility, and intensity of light during combustion, are often much interfered with by the presence of carbonic oxide and carbonic acid. Of the products obtained by the destructive distillation of coal and oil, Mr. Brande thinks that some are of what may be termed secondary formation; that is, that they result from the mutual action of the first formed gaseous products at high temperatures. Thus a peculiar compound of hydrogen and carbon, volatile and odorous, resembling tar in appearance, but having the characters of resin, is formed by passing pure olefiant gas through a tube of red-hot charcoal; and sulphuret of carbon is formed by the mutual agency of carburetted and sulphuretted hydrogen gases at high temperatures. To the latter compound the author refers the production of sulphurous acid, by the combustion of coal gas in cases where, by the test of acetate of lead, it is shown to be free from sulphuretted hydrogen. In this section of the paper the author further details some processes for the analysis of complex gaseous mixtures, which he thinks afford more accurate results, and are easier of performance than those usually practised, and which are rendered important as elucidating the nature of the gaseous products, now in common use for artificial illumination.

scholarly journals Gaseous combustion at high pressures. Part XV.— The formation of nitric oxide in carbonic oxide-oxygen-nitrogen explosions

1933 ◽  
Vol 139 (837) ◽  
pp. 74-83 ◽  
Keyword(s):  
Nitric Oxide ◽  
High Pressures ◽  
Volume Ratio ◽  
Optimum Composition ◽  
Normal Rate ◽  
Secondary Formation ◽  
Spherical Explosion ◽  
Rate Of Cooling ◽  
Hot Products

In previous papers of this series it was shown that the secondary formation of nitric oxide in CO-O 2 -N 2 explosions, when oxygen is present in excess of that required to burn all the carbonic oxide, rapidly increases with the density of the medium, the optimum composition of the medium for the purpose being 2CO + 3O 2 + 2N 2 . The former experiments were carried out, in bombs Nos. 2 and 3, the 7·5 cm. diameter spherical explosion chambers of which were each of 240 c.c. capacity with a surface/volume ratio 0·78, under conditions permitting of no acceleration in the normal rate of cooling down of the hot products from the maximum explosion temperature.

scholarly journals Gaseous combustion at high pressures. Part IV.—The influence of varying initial pressures upon the rate of pressure development and the activation of nitrogen in carbon monoxide-air explosions

1924 ◽  
Vol 105 (732) ◽  
pp. 406-433
Keyword(s):  
Carbon Monoxide ◽  
High Pressures ◽  
Vibrational Energy ◽  
Initial Pressure ◽  
Maximum Pressure ◽  
Time Interval ◽  
Pressure Development ◽  
The One ◽  
Air Explosion ◽  
Energy Absorbing

In the previous paper of this series it was shown :— (1) that when nitrogen is added as a diluent to a mixture of 2CO+O 2 undergoing combustion in a bomb at an initial pressure of 50 atmospheres, it exerts a peculiar energy-absorbing influence upon the system, far beyond that of other diatomic gases, or of argon; (2) that by virtue of such influence, it retards the attainment of maximum pressure in a much greater degree than can be accounted for on the supposition of its acting merely as a diatomic diluent; (3) that the energy so absorbed by the nitrogen during the combustion period, which extends right up to the attainment of maximum pressure, is slowly liberated thereafter as the system cools down ; and that consequently the rate of cooling is greatly retarded for a considerable time interval after the attainment of maximum pressure; (4) that there is no such energy-absorbing effect ( i. e ., other than a purely "diluent" one) when nitrogen is present in a 2H 2 +O 2 mixture similarly undergoing combustion ; but that, on the contrary, the presence of hydrogen in a CO-air mixture undergoing combustion at such high pressures so strongly counteracts the said " energy-absorbing " influence of the nitrogen, that it must be excluded as far as possible from the system before any large nitrogen-effect can be observed. These facts were explained on the supposition that there is some constitutional correspondence between CO and N 2 molecules (whose densities are identical) whereby the vibrational energy (radiation) emitted when the one burns is of such a quality as can be readily absorbed by the other, the two thus acting in resonance. It was further supposed that, in consequence of such resonance, nitrogen becomes chemically " activated " when present during the combustion of carbon monoxide at such high pressures ; and in conformity with this supposition, it was shown that such "activated" nitrogen is able to combine with oxygen more readily than does nitrogen which has merely been raised to a correspondingly high temperature in a hydrogen-air explosion.

scholarly journals Investigation of droplet nucleation in CCS relevant systems – design and testing of the expansion chamber

2018 ◽  
Vol 180 ◽  
pp. 02015 ◽  
Author(s):  
Miroslav Čenský ◽  
Jan Hrubý ◽  
Václav Vinš ◽  
Jiří Hykl ◽  
Bohuslav Šmíd
Keyword(s):  
Acoustic Waves ◽  
High Pressures ◽  
Systems Design ◽  
Helmholtz Resonator ◽  
Rapid Expansion ◽  
Acoustic Oscillations ◽  
Expansion Chamber ◽  
Gaseous Mixtures ◽  
Experimental Apparatus ◽  
Design And Testing

A unique in-house designed experimental apparatus for investigation of nucleation of droplets in CCS relevant systems is being developed by the present team. The apparatus allows simulating various processes relevant to CCS technologies. Gaseous mixtures with CO2 are prepared in a Mixture Preparation Device (MPD) based on accurate adjustment of flow rates of individual components [EPJ Web of Conferences 143, 02140 (2017)]. The mixture then flows into an expansion chamber, where it undergoes a rapid adiabatic expansion. As a consequence of adiabatic cooling, the mixture becomes supersaturated and nucleation and simultaneous growth of droplets occurs. In this study, we describe the design and testing of the expansion part of the experimental setup. The rapid expansion was realized using two valve systems, one for low pressures (up to 0.7 MPa) and the other for high pressures (up to 10 MPa). A challenge for a proper design of the expansion system is avoiding acoustic oscillations. These can occur either in the mode of Helmholtz resonator, where the compressible gas in the chamber acts as a spring and the rapidly moving gas in the valve system as a mass, or in the “flute” mode, where acoustic waves are generated in a long outlet tubing.

scholarly journals A recording calorimeter for explosions

1907 ◽  
Vol 79 (528) ◽  
pp. 138-154 ◽  
Keyword(s):  
Specific Heat ◽  
Heat Loss ◽  
Practical Importance ◽  
Copper Strip ◽  
Gas Engine ◽  
Coal Gas ◽  
Engine Cylinder ◽  
Solid Explosives ◽  
The Mean

The determination of the rate of loss of heat to the walls of a vessel after an explosion within it is a matter of considerable scientific interest and of practical importance. Hitherto such determinations, if we except the recent work of Dugald Clerk on the loss of heat in the gas engine cylinder, have been based upon a study of the fall of pressure during the cooling of the gases after the explosion. From the pressure the mean temperature can be deduced, and thence, if the specific heat is known, can be found the rate of heat loss at any moment. Such a calculation is, however, obviously unsatisfactory, because the only available values of the specific heat of gases at temperatures above 1500° are based upon explosion experiments, and involve doubtful assumptions as to the amount of loss before combustion is complete. Some means of determining the loss of heat at any instant without any knowledge of specific heat is therefore essential, both for finding the law of cooling of hot gases confined in a closed vessel and for placing on a satisfactory basis the specific heat values obtained from explosion experiments. I have devised a simple means of doing this which appears to be capable of considerable accuracy. It consists essentially in lining the explosion vessel as completely as possible with a continuous piece of copper strip and recording the rise of resistance of the copper strip during the progress of the explosion and the subsequent cooling. Knowing the temperature of the copper and its capacity for heat, the heat that has flowed into it from the gas may be calculated from the resistance, certain corrections being applied for the heat which the copper has lost to the insulating backing. Up to the present I have only used the apparatus for the investigation of the loss of heat after an explosion of coal gas and air, but it might, I think, be applicable, with certain modifications, to finding the heat loss during and after the combustion of solid explosives.

scholarly journals Gaseous combustion at high pressures. Part II. — The explosion of hydrogen-air and carbon monoxide-air mixtures

1921 ◽  
Vol 100 (702) ◽  
pp. 67-84 ◽  
Keyword(s):  
Carbon Monoxide ◽  
High Pressures ◽  
Maximum Pressure ◽  
Chemical Affinity ◽  
Actual Rate ◽  
Sensible Heat ◽  
Direct Relation ◽  
Explosive Mixture ◽  
The Subject ◽  
Time Required

In a previous paper upon the subject, the question was propounded whether or no there is any direct relation between the actual rate at which the potential energy of an explosive mixture is transferred on explosion as sensible heat to its products and the magnitude of the chemical affinity between its combining constituents. As the result of an experimental enquiry into the matter, it was proved:– ( a ) that, whereas the affinity for oxygen of methane is at least twenty to thirty times greater than that of hydrogen, the time required for the attainment of maximum pressure in the case of the primary methane-air mixture (CH 4 + O 2 + 4N 2 ) is at least some five to eight times as long as that required in the case of the primary hydrogen-air mixture (2H 2 + O 2 + 4N 2 );

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