NOx and CO emissions from a pulse combustor operating in a lean premixed mode

Keller, Jay O.; Bramlette, T.T.; Barr, P. K.; Alvarez, J.R.

doi:10.1016/0010-2180(94)90037-x

Cited by 43 publications

(10 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…60) Taking concentration values at steady conditions as a reference, the decreases were 52-100 % for NO and 53-90 % for CO depending on SPL (136 to 146 dB), frequency (80 to 240 Hz) and excess air (10 to 50 %). Another example is the work 62) the authors of which obtained emissions levels of a premixed methane-air flame below 5 ppm for NO x and CO.…”

Section: Reduction Of Combustion-related Pollutant Emis-mentioning

confidence: 99%

High Power Ultrasonics in Pyrometallurgy: Current Status and Recent Development

2005

View full text Add to dashboard Cite

In recent years, a large number of studies have been published on the use of high intensity ultrasonics in various high temperature technologies. This paper provides an overview of the recent achievements and ongoing works on the application of high intensity sound waves to pyrometallurgy and its related areas. The published results have strongly suggested that ultrasonics has the potential to play a more significant role in such areas as the dedusting of high-temperature exhaust gas, improvement of fuel-combustion efficiency, control of air-pollutant emissions, improvement of the quality of ingots, production of metal powders and ascast composite materials.At higher temperatures, special attractiveness of sound waves is associated with the fact that the waves can propagate through gas, liquids, and solids, and thus supply the acoustic energy from a cooled sonic generator to materials being processed under high temperature conditions. This provides a unique tool, for example, for controlling the rates of interfacial phenomena that is unachievable by any other methods under high temperatures.Industrial competitiveness of the ultrasonic-based technologies is reinforced by the relatively low cost of power-generating equipment and ultrasonic transducers. However, further research efforts are called for to develop new heat-resistant waveguide materials and to integrate the ultrasonic installations with existing industrial facilities in high temperature technologies.KEY WORDS: pyrometallurgy; high temperature; sonoprocessing; high power ultrasonics; non-linear phenomena; air pollutants; continuous casting; melt atomization; cast composites.applications have been summarized in a book by one of the authors of the present review. 4)The following two circumstances make ultrasonics especially applicable to high-temperature technologies: 1) There is a severely limited choice of techniques available for supplying energy under conditions involving higher temperatures. Among these techniques, sonic/ ultrasonic treatment or sonoprocessing should be competitive as regards both technique and cost, because it provides an effective transmission of acoustic energy from the ultrasonic generators to the materials being processed at a relatively low cost for ultrasonic equipment. 2) It is well-known that interfacial phenomena play an important role in governing many high-temperature processes. Examples are mass and heat transfer, crystal growth during the solidification of liquid metals, wetting, and emulsification. Sonic and ultrasonic waves propagate through homogeneous elastic mediums without significant losses. However, when the waves are incident upon an interface, the scattering or reflecting or of the waves from the interface is responsible for a number of nonlinear phenomena that occur at the interfaces. These provide a unique tool for controlling the rates of interfacial phenomena. Such a tool is unachievable by any other methods. Along with improvements in the earlier methods of sonoprocessing, a number of new ultrasonic appl...

show abstract

Section: Reduction Of Combustion-related Pollutant Emis-mentioning

confidence: 99%

High Power Ultrasonics in Pyrometallurgy: Current Status and Recent Development

2005

View full text Add to dashboard Cite

show abstract

“…NO x reduction level was found to be strongly dependent on the experimental conditions. The reported values are ranged from 100% ( Delabroy et al,1996) to 15% (Keller et al,1994) decrease in NO x emission rate as compared with that for steady flow conditions. The suppression mechanism has been well established.…”

Section: Reduction Of Combustion-related Pollutant Emissionmentioning

confidence: 99%

“…Taking concentration values at steady conditions as a reference, the decreases were 52 ~100% for NO and 53~90% for CO depending on SPL (136 to 146 dB), frequency(80 to 240 Hz) and excess air (10 to 50%). Another example is the work (Keller et al, 1994) the authors of which obtained emissions levels of a premixed methane-air flame below 5 ppm for NO x and CO. Few studies examined the effect of forced acoustics on soot emission from different types of flame: a spray ethanol flame of a Rijke tube combustor (Mcquay et al, 1998), acetylene (Saito et al,1998) and methane diffusion flames (Demare & Baillot, 2004;Hertzberg, 1997). The oscillation frequencies were also different: 200 Hz (Demare & Baillot, 2004 ) , 40~240 Hz (Mcquay et al, 1998), < 100 Hz (Saito et al, 1998) and 40~1000 Hz (Hertzberg, 1997).…”

Section: Reduction Of Combustion-related Pollutant Emissionmentioning

confidence: 99%

Application of Airborne Sound Waves to Mass Transfer Enhancement

Komarov¹

2011

Advanced Topics in Mass Transfer

View full text Add to dashboard Cite

“…In general, this combustion technique offers advantages like efficient combustion and low emissions of NO x and CO [2]. Distinctive features of the pulse combustors are the high wall heat transfer, which makes them valuable for thermal applications, and the high thrust/weight ratio when used as jet engines for aeronautic propulsion.…”

Section: Introductionmentioning

confidence: 99%

An Efficient Numerical Model of Pulsating Combustion and Its Experimental Validation

Casarsa

Giannattasio

Micheli

2009

Volume 3: Combustion Science and Engineering

View full text Add to dashboard Cite

A simple and efficient numerical model is presented for the simulation of pulse combustors. It is based on the numerical solution of the quasi-1D unsteady flow equations and on phenomenological sub-models of turbulence and combustion. The gas dynamics equations are solved by using the Flux Difference Splitting (FDS) technique, a finite-volume upwind numerical scheme, and ENO reconstructions to obtain secondorder accurate non-oscillatory solutions. The numerical fluxes computed at the cell interfaces are used to transport also the reacting species, their formation energy and the turbulent kinetic energy. The combustion progress in each cell is evaluated explicitly at the end of each time step according to a second-order overall reaction kinetics. In this way, the computations of gas dynamic evolution and heat release are decoupled, which makes the model particularly simple and efficient. A comprehensive set of measurements has been performed on a small Helmholtz type pulse-jet in order to validate the model. Air and fuel consumptions, wall temperatures, pressure cycles in both combustion chamber and tail-pipe, and instantaneous thrust have been recorded in different operating conditions of the device. The comparison between numerical and experimental results turns out to be satisfactory in all the working conditions of the pulse-jet. In particular, accurate predictions are obtained of the device operating frequency and of shape, amplitude and phase of the pressure waves in both combustion chamber and tail-pipe.

show abstract

NOx and CO emissions from a pulse combustor operating in a lean premixed mode

Cited by 43 publications

References 6 publications

High Power Ultrasonics in Pyrometallurgy: Current Status and Recent Development

High Power Ultrasonics in Pyrometallurgy: Current Status and Recent Development

Application of Airborne Sound Waves to Mass Transfer Enhancement

An Efficient Numerical Model of Pulsating Combustion and Its Experimental Validation

Contact Info

Product

Resources

About