Abstract
The correlation between atomization quality and the destruction efficiency of hazardous organic compounds was studied in a turbulent spray flame. The atomization quality was varied by both changing spray nozzle parameters and by inducing disruptive droplet combustion (secondary atomization) within the flame. The primary atomization quality was characterized by laser diagnotic size distribution measurements. The secondary atomization quality was determined from observations of disruptive atomization intensity on a train of monodisperse droplets within a high-temperature laminar reactor. For the primary atomization work, No. 2 fuel oil was doped with four target hazardous organic compounds (acrylonitrile, chloroform, benzene, and monochlorobenzene). The destruction efficiency of these compounds was measured under correct atomizer operating parameters and under off-design conditions in which the spray quality was degraded. The degraded spray quality conditions resulted in decreased destruction efficiency of the waste, and increased combustion intermediate emissions (carbon monoxide and total hydrocarbons). Comparison of measured droplet size distributions with performance showed that destruction efficiency was more closely correlated with the large droplet wing of the dropsize distribution than with the mean droplet size. A droplet evaporation/ trajectory model showed that the appearance of the target compounds in the exhaust corresponded with the fraction of the droplets that passed through the primary reaction zone unevaporated. The distruptive droplet combustion results showed that hazardous waste compounds are capable of inducing secondary atomization. Testing of benzal chloride (which did not cause the turbulent flame reactor showed that the occurrence of disruptive combustion correlated with increased target compound destruction efficiency and reduced combustion intermediate emissions. Thus, the results suggest that the presence of certain compounds or additives in waste streams may assist in obtaining improved performance when primary atomization is poor, as it is for slurry or sludge waste streams.
Highlights
Incineration offers a final and complete means of disposing organic hazardous wastes
Understanding of the incineration process is complicated by the complex chemistry involved in the destruction of hazardous waste compounds, and by the strong coupling between transport rate processes and chemical rates that are evident in practical systems
The nozzles were operated at both the design points and under off-design conditions. These results were compared with the target compound destruction efficiency obtained using these nozzles in the turbulent flame reactor
Summary
Incineration offers a final and complete means of disposing organic hazardous wastes. We identified poor atomization quality as one mode by which an incinerator flame zone could fail to efficiently destroy waste.[4] The objective of the present work is to explore this "failure condition" and to develop an understanding of the mechanism and consequences associated with both a degradation in primary atomization and the promotion of secondary atomization by disruptive droplet combustion. In the second portion of the study, the influence of disruptive droplet combustion or "secondary atomization" on waste destruction efficiency was investigated.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
