On the Occurrence of Transient Puffs in a Rotary Kiln Incinerator Simulator I. Prototype Solid Plastic Wastes

An Equilibrium Analysis of Some Chlorinated Hydrocarbons in Stoichiometric to Fuel-rich Post-flame Combustion Environments

“…One can imagine that the fraction of rich "pockets" or "plugs" need be only one in 10,000 on average to account for the levels of PICs and POHCs occasionally observed in incinerator testing. 24 Linak et al 25 have found that high temperatures can exacerbate the occurrence of transient "puffs" in kilns. Note that high temperature alone may not serve as a solution for the elimination of the CHCs as they must subsequently pass through a cooling zone where the thermodynamic tendency is for them to re-form.…”

“…Certain types of combustion devices such as rotary kilns, because of the manner of their operation or geometry, are inherently subject to nonstoichiometric "puffs" or "plugs." 25 In such systems, homogenization of the waste feed appears to be especially important. One can imagine a situation where a container of chlorinated solvent or highly chlorinated solids, e.g., PVC, were loaded into a rotary kiln, leading to chlorine-rich vapors that pass through the kiln.…”

Basic Research on the Emission of Polycyclic Aromatic Hydrocarbons caused by Waste Incineration

“…It was proved that the PAH were formed in plastics combustion. 12 ' 13 Also, there appears to be a trend of increased amounts of PAH at high temperatures because of incomplete combustion. 12 For that reason, these data indicate that substantial amounts of these compounds can be created between the feed inlet and the stack under the rather poor combustion conditions of these diagnostic experiments.…”

Research Areas for Improved Incineration System Performance

“…Facilities such as the EPA rotary kiln simulator located at Research Triangle Park, North Carolina 20 should be helpful in providing data on the thermal decomposition/evaporation behavior under flame conditions. The establishment of relationships between the TGA non-flame thermal behavior data and flame decomposition/evaporation* data would be very helpful.…”

“…If there is inadequate air/fuel mixing, increasing temperature alone can improve performance slightly. 20 However, the small improvement observed should be the result of improved air/fuel mixing due to increased diffusion mixing at higher temperatures rather than kinetics considerations. Turbulent mixing is a parameter which is very difficult to quantify and may be the main reason for the misconception that time and temperature are the most important factors.…”