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Showing papers on "Combustion published in 1972"


Journal ArticleDOI
TL;DR: In this article, a theoretical discussion of reaction kinetics in porous media is presented and applied to the in situ combustion processes and it is observed that there is some similarity between the kinetics of reverse and wet forward combustion processes.
Abstract: After general remarks on the oxidation reactions of hydrocarbons involved in in situ combustion, the heat releases are estimated and a formula is derived for computing the heat of combustion in the high temperature zone. Then a theoretical discussion of reaction kinetics in porous media is presented and applied to the in situ combustion processes. It is observed that there is some similarity between the kinetics of reverse and wet forward combustion processes. Furthermore, the influence of rock matrix properties on crude oil oxidation is illustrated by differential thermal analysis experiments. This observation is of great importance for practical applications. Some information concerning the use of low temperature oxidation data and the value of the reaction order with respect to oxygen partial pressure is derived from the interpretation of reverse combustion experiments using a numerical model. (16 refs.)

201 citations


Journal ArticleDOI
TL;DR: In this paper, the authors report on the study of auto-ignition of hydrocarbon-oxygen mixtures behind reflected shock waves, and the pressure-temperature limits between these regions of mild and strong ignition were determined.

176 citations


Journal ArticleDOI
TL;DR: In this paper, the burning rates of hexadecane droplets 0.5 to 1 mm in diameter, suspended on quartz fibers in room-temperature air, at pressures from 1 to 0.1 atm.

174 citations



Journal ArticleDOI
21 Apr 1972-Science
TL;DR: It is concluded that carbon monoxide is produced at a rate of 5x1015 grams per year, a value some 25 times greater than the rate ofcarbon monoxide production from combustion, and hydroxyl radicals are shown to account for both the production of this large amount of carbonmonoxide by methane oxidation and for its removal by carbon mon dioxide oxidation.
Abstract: Consideration of the steady-state equations for stable carbon monoxide and for radioactive carbon monoxide in the troposphere leads to the conclusion that carbon monoxide is produced at a rate of 5x10(15) grams per year, a value some 25 times greater than the rate of carbon monoxide production from combustion. The concomitant residence time for carbon monoxide is 0.1 year, in agreement with a previous estimate of Weinstock. Hydroxyl radicals are shown to account for both the production of this large amount of carbon monoxide by methane oxidation and for its removal by carbon monoxide oxidation. The average concentration of hydroxyl radicals in the troposphere required to achieve this effect is 2.3x10(6) molecules per cubic centimeter, with a daytime concentration of twice that. Levy and McConnell, McElroy, and Wofsy have deduced concentrations of hydroxyl radicals in the troposphere of the same magnitude from purely photochemical considerations, in support of this model.

151 citations


Journal ArticleDOI
25 Nov 1972-BMJ
TL;DR: Carbon monoxide is produced from technological and natural sources in an estimated global amount of at least 250 million tons a year and fuel combustion by motor vehicles is the major source.
Abstract: Carbon monoxide is produced from technological and natural sources in an estimated global amount of at least 250 million tons a year. Fuel combustion by motor vehicles is the major source. The gas is released to the air, and since the background level does not increase it is assumed that oxidation to carbon dioxide takes place in the upper atmosphere. /Author/

129 citations


Journal ArticleDOI
TL;DR: In this paper, the isotopic composition of atmospheric CO in the northern hemisphere has been studied and the most likely nature of these sources is discussed and the production rates estimated. But the isotope pattern is different from that for CO from automobile engine combustion, whether compared to combustion in the same region as the air sample or to an estimated world average.

122 citations


Book
01 Jun 1972
TL;DR: In this article, a standard text for the automotive industry explains in detail the fundamentals of emission formation and control for gasoline and diesel engines, which can be applied to other combustion systems, such as gas turbines and stationary power plants.
Abstract: This standard text for the automotive industry explains in detail the fundamentals of emission formation and control for gasoline and diesel engines. These concepts can be applied to other combustion systems, such as gas turbines and stationary power plants. Topics of discussion include: combustion in homogeneous mixtures; effect of design and operating variables on gasoline engine exhaust emissions; hydrocarbon evaporation emissions; diesel engine combustion emissions and controls; emission instrumentation; and automotive exhaust emission testing. 200 references, 197 figures.

121 citations


Journal ArticleDOI
TL;DR: In this article, it is shown that the far field sound pressure is directly proportional to the first Eulerian time derivative of the chemical reaction rate integrated over the reacting volume, and the characteristics of the correlation function for this reaction rate time derivative are investigated through elementary reasoning for several simple premixed turbulent flame models.

112 citations


Journal ArticleDOI
TL;DR: In this paper, the enthalpies of combustion were determined on two different samples of p-chlorobenzoic acid in three series of measurements under widely varied conditions.

105 citations


Patent
21 Apr 1972
TL;DR: In this paper, an initial honeycomb-type catalyst is used to purify exhaust gases from an internal combustion engine and an excess of extraneous fuel is fed to the initial catalyst to reduce nitrogen oxides to nitrogen.
Abstract: Exhaust gases from internal combustion engines are purified by catalytic treatment. The systems have an initial catalyst, preferably in a separate vessel near the engine, and a subsequently-in-line catalyst. Preferably, the catalysts are of the honeycomb-type. The exhaust gases and an excess of oxygen, with or without a supplemental fuel, are passed through the initial catalyst during the start-up of the engine to insure that the exhaust gases are purified more or less as soon as the engine begins operation. In order to reduce the amount of nitrogen oxides in the exhaust gas after start-up, an excess of extraneous fuel is fed to the initial catalyst to reduce nitrogen oxides to nitrogen. The subsequently-in-line catalyst serves to reduce the carbon monoxide and hydrocarbon contents of the exhaust gases.

Journal ArticleDOI
TL;DR: In this article, a two-wavelength radiation pyrometer was developed for the purpose of measuring the temperatures of pulverized fuel particles burning in suspension in the presence of carbon monoxide in the immediate vicinity of the particles.

Journal ArticleDOI
TL;DR: In this paper, it was shown that ignition of the boron particles, inhibited by the presence of a coating of oxide, is likely the controlling process, and the prediction of whether or not a given particle will ignite and, if it will, the time required for ignition.
Abstract: Results of experimental studies of the afterburning of the exhausts of highly boron-loaded, fuel-rich propellants with air and results of boron single particle combustion studies have been examined for definition of limiting processes causing incomplete combustion of boron in typical afterburners, particularly at low afterburner pressure. This examination indicates that ignition of the boron particles, inhibited by the presence of a coating of boron oxide, is likely the controlling process. Transient differential equations describing the generation and removal of oxide and the temperature history of a particle have been derived, converted to difference equation form and programmed for computer solution to permit prediction of whether or not a given particle will ignite and, if it will, the time required for ignition. Predicted ignition times for particles studied by Macek in a flat-flame burner have been compared with his experimental results—reasonably good agreement has been obtained. The progr...

Patent
24 Oct 1972
TL;DR: In this paper, a temperature sensing device senses the temperature of the reactors, and air is admitted to the exhaust system of the engine to control the temperature thereof; an oxygen signal is being sensed representative of oxygen component in the engine and the mass ratio of air to fuel of the mixture supplied to the engine is controlled to provide for proper air-fuel ratio with minimum noxious exhaust.
Abstract: A reactor to oxidize unburned hydrocarbons and carbon monoxide is connected to the exhaust system of the engine. A further reactor is connected to the exhaust system designed to reduce nitrogen-oxygen compounds (NOx). A temperature sensing device senses the temperature of the reactors, and air is admitted to the exhaust system of the engine to control the temperature thereof; an oxygen signal is being sensed representative of oxygen component in the exhaust system of the engine and the mass ratio of air to fuel of the mixture supplied to the engine is controlled to provide for proper air-fuel ratio with minimum noxious exhaust. The two control loops thus formed are interconnected by the internal combustion engine, the control effects of the two control loops being balanced with respect to each other.

Patent
Wahl J1, Zechnall R1, Schmidt P1
30 Mar 1972
TL;DR: In this paper, an oxygen analyzer responsive to oxygen partial pressure and comprising an oxygen ion conductive solid electrolyte is exposed to the exhaust gases of an internal combustion engine, and the sensed value is applied to a low pass filter which is interconnected in an electrical circuit to control the amount of fuel being admitted, relative to air, so that the air-fuel ratio of the air fuel mixture can be maintained at a predetermined level.
Abstract: An oxygen analyzer responsive to oxygen partial pressure and comprising an oxygen ion conductive solid electrolyte is exposed to the exhaust gases of an internal combustion engine. The sensed value is applied to a low pass filter which is interconnected in an electrical circuit to control the amount of fuel being admitted, relative to the amount of air, so that the air-fuel ratio of the air-fuel mixture can be maintained at a predetermined level. In one embodiment, the mixture is regulated to provide a minimum of unburnt hydrocarbon and carbon monoxide in the exhaust, the remaining noxious exhaust gases formed primarily of nitrogen compounds being neutralized by a catalytic converter, so that the catalytic converter need have only single bed neutralizing only one substantial noxious exhaust component. Control of the amount of fuel can be obtained either by controlling the amount of fuel injected in an injection system, or controlling an additional air path. Sensing of other parameters, such as CO, temperature, and the like, may also be provided.

Patent
Bethel G1
25 Sep 1972
TL;DR: A process for combustion comprising introducing materials for combustion and exposing them to an electrical charge which can be an electrostatic charge provided through a corona discharge means or any other suitable means to charge the respective materials that are to be combined in the combustion process is described in this paper.
Abstract: A process for combustion comprising introducing materials for combustion and exposing them to an electrical charge which can be an electrostatic charge provided through a corona discharge means or any other suitable means to charge the respective materials that are to be combined in the combustion process The materials for combustion can be specifically a hydrocarbon and air which can be respectively charged negatively or positively to effectuate a greater attraction and mixing of the respective portions of the combustion materials prior to combustion Furthermore, the portions of the combustion materials which can form radicals can be affected by electrostatic forces to increase or decrease the reactive electrons or formulate them in such a manner so that they will react in a more favorable manner For instance, hydrocarbon materials can be at least partially cracked in order to place them in a state closer to the actual products that reach a final state of combustion Apparatus is disclosed for practicing the foregoing process by means of different combustion configurations wherein positive and negative charges can be applied to the materials for combustion Specifically, a corona discharge means, as well as electrical charging means, can be employed to apply the foregoing charges to create radicals or more intimate mixing of the combustion materials to a state closer to the completed combustion process The apparatus incorporates means for introducing both primary and secondary materials of combustion so as to combine them in optimum conditions depending on the nature of the hydrocarbons to be reacted

Patent
01 May 1972
TL;DR: In this article, a device for controlling the air-fuel ratio lambda of the mixture supplied to a combustion engine, comprising a pick-up sensitive to the carbon monoxide content of a gas mixture and arranged in an exhaust gas duct of the engine and producing a voltage increasing with said content, was presented.
Abstract: Device for controlling the air-fuel ratio lambda of the mixture supplied to a combustion engine, comprising a pick-up sensitive to the carbon monoxide content of a gas mixture and arranged in an exhaust gas duct of the engine and producing a voltage increasing with said content, a member for controlling the air-fuel ratio lambda and a feedback mechanism acting upon said member so that the ratio lambda is increased when the voltage produced by the pick-up increases.


Patent
Koch Christian Dipl-Ing1
23 Jun 1972
TL;DR: In this article, a perforated sintered block is used for combustion of gaseous or vaporous fuel-air mixtures without using a catalyst in the mixing chamber.
Abstract: Flameless combustion of gaseous or vaporous fuel-air mixtures is accomplished without a catalyst in a perforated sintered block which forms one wall of a mixing chamber. The fuel air mixture is first passed through the perforated sintered block at a relatively low flow rate and burned at the entrance surface of the block until the latter has reached a temperature of approximately 950* C. At that point, the flow rate of the fuelair mixture is increased by approximately 10 to 50 times to cause the combustion to take place within the perforated sintered block and the temperature of the latter to be increased to approximately 1,000* to 2,000 * C.

Patent
Josef Dipl Ing Wahl1, P Schmidt1
23 Jun 1972
TL;DR: In this paper, the inlet manifold of an internal combustion engine over a first path, the amount of air being controlled in accordance with a command input, for example to control operation of the engine.
Abstract: Air and fuel are applied to the inlet manifold of an internal combustion engine over a first path, the amount of air being controlled in accordance with a command input, for example to control operation of the engine. The oxygen content in the exhaust gases is measured and additional air is applied to the inlet manifold of the engine over a second path, the amount of additional air being supplied over the second path being controlled in accordance with (a) the amount of air admitted through the first path and, additionally, (b) in accordance with the measured oxygen content of the exhaust gases.


Journal ArticleDOI
TL;DR: In this paper, the authors illustrate the propagation of combustion in vortex rings formed of premixed propane and air (or oxygen) and measure the mean flame propagation speed and the vortex strength indicate that over the range of strengths used in the equipment the relationship is approximately linear.

Patent
22 May 1972
TL;DR: In this paper, the authors proposed a method to control the production of nitrogen oxides by providing successive stages of combustion and by holding down the temperature of combustion. But this method requires the fuel in two streams of unequal volume and comprising respectively more and less than the stoichiometric percentage of air, igniting the streams in sequence.
Abstract: In the operation of a burner using gaseous fuel the production of nitrogen oxides is limited and controlled by providing successive stages of combustion and by holding down the temperature of combustion. This is accomplished by introducing the fuel in two streams of unequal volume and comprising respectively more and less than the stoichiometric percentage of air, igniting the streams in sequence, thus effecting first and second stages of combustion, and mixing and consuming the excess fuel and air of said streams respectively, thus effecting a third stage of combustion.

Patent
C Koch1
18 Jan 1972
TL;DR: In this article, the authors present a method and apparatus for the combustion of a fuel, free of detrimental substances, in a combustion engine, where the fuel, together with oxygen containing gas, is passed over a catalyst for conversion into a gas mixture of methane and carbon monoxide.
Abstract: Method and apparatus for the combustion of a fuel, free of detrimental substances, in a combustion engine. The fuel, together with oxygen containing gas, is passed over a catalyst for conversion into a gas mixture of methane and carbon monoxide. Passing the gas mixture together with additional oxygen containing gas to the combustion engine whereat the gas mixture is burned producing an exhaust gas. Feeding part of the exhaust gas to the fuel, prior to the conversion of the fuel.

Patent
C Douglas1, W Young1, J Phillips1
15 May 1972
TL;DR: In this article, the authors proposed a method for the discharge of products of combustion from the combustion chamber of a submerged burner into and through the body of a heat-sensitive solution, handled in such manner as to reduce air pollution resulting from the practice of the submerged combustion process with respect to the given solution, as well as improve the effectiveness of the burner, per se, and the submerged combustion process.
Abstract: Improvements in submerged combustion evaporators and heaters particularly adapted to the heating and evaporation of various heat sensitive solutions, including both methods and apparatus therefor; Improved apparatus and methods for the discharge of products of combustion from the combustion chamber of a submerged burner into and through the body of a heat-sensitive solution, said discharge handled in such manner as to reduce air pollution resulting from the practice of the submerged combustion process with respect to the given solution, as well as improve the effectiveness of the burner, per se, and the submerged combustion process.

Patent
G Moss1
06 Dec 1972
TL;DR: In this paper, a mixture of CaO and MgO is used for partial combustion and full combustion at 800*-950*C in a bed of caO and mgO which combines with the sulphur.
Abstract: Fuels containing sulphur are purified by (a) partial combustion or (b) full combustion, at 800*-950*C in a bed of CaO and/or MgO which combines with the sulphur. The sulphurized CaO or MgO is reactivated by contact with a regenerator gas at 1,000*-1,150*C with the evolution of SO2. Vanadium and sodium removal from the fuel is enhanced by the presence of iron and alumina, respectively.

Journal ArticleDOI
TL;DR: In this article, an analysis of the sound field in the combustion can is presented in which the axial temperature and density gradients are taken into account, and the analysis includes calculation of the acoustic transfer impedance at the burner plane.

Patent
02 Mar 1972
TL;DR: In this paper, a method is proposed for the reduction of NITROGEN OXIDES in EXHAUST GASES from INTERNAL COMBUSTION ENGINES.
Abstract: A METHOD IS PROPOSED FOR THE REDUCTION OF NITROGEN OXIDES IN EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES TO SELECTIVELY FORM NITROGEN AS SUBSTANTIALLY THE ONLY NITROGEN-CONTAINING PRODUCT. THE METHOD COMPRISES CONTACTING AN EXHAUST GAS FROM AN INTERNAL COMBUSTION ENGINE AT AN ELEVATED TEMPERATURE IN A REDUCING ATMOSPHERE WITH RHODIUM AND RUTHENIUM.

Patent
18 Jul 1972
TL;DR: In this article, it is proposed that combustion gases are bled off from a gas turbine engine and their composition adjusted by burning extra fuel in the bleed gases or adding extra substances.
Abstract: In a high powered laser system it is proposed that combustion gases be bled off from a gas turbine engine and their composition adjusted by burning extra fuel in the bleed gases or adding extra substances. Suitable aerodynamic expansion produces a population inversion resulting in laser action in the CO2 species. Alternatively, bleed gases may be taken from the high pressure compressor of the gas turbine engine and an appropriate fuel burnt therein. If required, other adjustments may also be made to the composition and the resulting gaseous mixture subjected to aerodynamic expansion to induce laser action as before.

Patent
25 Aug 1972
TL;DR: An improved process for pre-treating and melting glassmaking materials is proposed in this paper, in which the glass batch is compacted or agglomerated into distinct units, preheated and then conveyed into a glass furnace or melter.
Abstract: An improved process for pre-treating and melting glassmaking materials wherein, in a preferred embodiment, the glass batch is compacted or agglomerated into distinct units, preheated and then conveyed into a glass furnace or melter. The glass batch preferably is compacted into briquets using an improved process, and the glass batch is preheated with the combustion gases from the glass furnace in a fashion such that particular matter, particularly sodium sulfate, is removed from the combustion gases. Melting preferably is accomplished using a submerged combustion process.