ESTIMATION OF METHODOLOGY AND VALIDATION OF PARTICULATE ENTRAINMENT IN A PILOT-SCALE ROTARY KILN-BASED HAZARDOUS-WASTE INCINERATOR

Combustion gas particulate entrainment from rotary kiln hazardous wast e incinerators (HWI) is a necessary design data requirement because of its impact on the design and operation of the downstream process equi pment. The particulate leaving the rotary kiln off-gases may slag in t he secondary combustion chamber (SCC). The potential to slag and the p roblems slagging can cause are dependent upon the SCC burner design, t he mineralogical composition of the praticulate, and the SCC operating temperature. Some entrained particulate may adhere to the walls or fa ll out in the SCC as a dust/slag; the remainder of the particulates wi ll be conveyed by the flue gas to the downstream air pollution control (APC) system. If a wet APC system is used, the particulates would be discharged to a wastewater treatment system (WTS) or publicly operated treatment works (POTW). A literature search was conducted to determin e the knowledge base for particulate carry-over from a countercurrent rotary kiln processing sedimentary solids. No data existed for this ty pe soil. A pilot test was, therefore, conducted to experimentally meas ure the potential entrainment rate of this material. A detailed discus sion of the entrainment mechanisms, pilot test equipment, sampling pro cedure, test conditions simulating the commercial operation, particle size distribution (PSD) of the ash sample, percent carry-over rate, an d measured PSD of the kiln particulate carry-over are presented in thi s article. A mathematical model was developed by the authors to predic t the pilot test results. The PSD of incinerator ash was used to calcu late percent carry-over rate and PSD of the entrained solids. A compar ison of experimental versus estimated results for estimating entrainme nt are presented in this article.