Rotary kiln incinerators, like the other types, are designed with
• A primary chamber, where the waste is heated and volatilized, and
• A secondary chamber, where combustion of the volatile fraction is completed.
The primary chamber consists of a slightly inclined, rotating kiln in which waste materials migrate from the feed end to the ash discharge end.
The waste throughput rate is controlled by adjusting the rate of kiln rotation and the angle of inclination.
Volatiles and combustion gases pass from the primary chamber to the secondary chamber.
The secondary chamber operates at excess air. Combustion of the volatiles is completed in the secondary chamber.
Due to the turbulent motion of the waste in the primary chamber, solids burnout rates and particulate entrainment in the flue gas are higher for rotary kiln incinerators than for other incinerator designs.
As a result, rotary kiln incinerators generally have add-on gas cleaning devices
References:
GOI 2009. TECHNICAL INSTRUCTIONS ON INCINERATOR; DTE OF WORKS ENGINEER-IN-CHIEF’S BRANCH INTEGRATED HQ OF MOD (ARMY)
US Environment Protection Agency website. Medical Waste Incineration: available at: https://www3.epa.gov/ttnchie1/ap42/ch02/final/c02s03.pdf accessed on 20th September 2017
Rotary Kiln: http://www.ihatepsm.com/blog/rotary-kiln-incinerator
Double Chamber Incinerator: http://www.ihatepsm.com/blog/double-chambered-incinerator