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Combustion burner effects

In a catalytic burner, the combustion is ignited and stabilized under ultra-lean conditions, which results in adiabatic temperatures close to those allowed for delivering the hot compressed gas to the turbine. Hence the need for by-pass air is minimized and the formation of thermal NOj, is almost prevented due to the absence of a hot combustion zone. Reduction of N emission has been reported to be even larger than expected from the lower combustion temperature if a significant fraction of the fuel is oxidized on the catalyst surface [3]. This effect has been attributed either to the reduction in the formation of prompt NO in view of the... [Pg.364]

Basically, there are three methods of supplying a burner wifh combustion air, first by natural suction using natural draft (this supply may be enhanced by an ejection effect generated by fuel jefs). The second fype of air supply is induction air suction. This kind of air supply works... [Pg.412]

Tightening environmental regulations are requiring the deployment of cost-effective NOx control technologies and are providing opportunities for the development of new technologies. Promising research horizons include low-NOx burners, catalytic combustion, NO decomposition, hydrocarbon (or methane)-SCR and simultaneous NOx and SOx control. [Pg.11]

TTte most cost-effective methods of reducing emissions of NO are the use of low-NO burners and the use of low nitrogen fuels such as natural gas. Natural gas has the added advantage of emitting almost no particulate matter or sulfur dioxide when used as fuel. Other cost-effective approaches to emissions control include combustion modifications. These can reduce NO emissions by up to 50% at reasonable cost. Flue gas treatment systems can achieve greater emissions reductions, but at a much higher cost. [Pg.28]

Enclosed flares are composed of multiple gas burner heads placed at ground level in a staeklike enclosure that is usually refractory or ceramic lined. Many flares are equipped with automatic damper controls that regulate the supply of combustion air depending on temperature which is monitored upstream of the mixing, but inside the staek. This class of flare is becoming the standard in the industry due to its ability to more effectively eontrol emissions. Requirements on emissions includes carbon monoxide limits and minimal residence time and temperature. Exhaust gas temperatures may vary from 1,000 to 2,000 F. [Pg.487]

If the products of combustion can be diluted so that the carbon dioxide content is not greater than 1 per cent it is permissible to discharge them at ground level. This is the principle of the system shown in Figure 19.7, in which fresh air is drawn in to dilute the flue products which are discharged preferably on the same wall as the inlet to balance against wind effects. It is essential to interlock the airflow switch with the burner controls. [Pg.270]

The range of satisfactory operation for a gas burner, defined by light-back, blow-off and incomplete combustion is limited. The variation in gas analyses, particularly higher hydrocarbons and inerts, can influence the range of operation. This has led to the definition of different groups of natural gas. A practical effect is that burners designed for the European continent may not be suitable for the UK without adjustment. This does not apply to forced-draft burners. [Pg.275]

Open flares have a flare tip with no restriction to flow, the flare tip being the same diameter of the stack. Open flares are effectively a burner in a tube. Combustion and mixing of air and gas take place above the flare with the flame being fully combusted outside of the stack. [Pg.264]

The Presumed Probability Density Function method is developed and implemented to study turbulent flame stabilization and combustion control in subsonic combustors with flame holders. The method considers turbulence-chemistry interaction, multiple thermo-chemical variables, variable pressure, near-wall effects, and provides the efficient research tool for studying flame stabilization and blow-off in practical ramjet burners. Nonreflecting multidimensional boundary conditions at open boundaries are derived, and implemented into the current research. The boundary conditions provide transparency to acoustic waves generated in bluff-body stabilized combustion zones, thus avoiding numerically induced oscillations and instabilities. It is shown that predicted flow patterns in a combustor are essentially affected by the boundary conditions. The derived nonreflecting boundary conditions provide the solutions corresponding to experimental findings. [Pg.205]


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See also in sourсe #XX -- [ Pg.25 ]




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