Yoshitada Kakuta*, Hiroyuki Adachi*, Nobutoshi Tanaka** and Toshihiko Matsuto**

* Environmental Engineering Department-1, Engineering Division, TAKUMA Co., Ltd.
** Department of Environmental and Sanitary Engineering, Faculty of Engineering, Hokkaido University

+ Correspondence should be addressed to Yoshitada Kakuta:
(2-2-33 Kinrakuji-cho, Amagasaki 660 Japan)

Abstract

The gas flow pattern is experimentally visualized in the combustion chamber of a municipal solid waste (MSW) incinerator. The Tracer method with soap bubbles is applied to the cold transparent model of the chamber and paths of many soap bubbles are recorded by a video recorder.

Path line diagrams, mixing index and velocity vector diagrams are produced by processing and analyzing video data. The path line diagram is useful to understand visually gas flow behavior in the chamber. The velocity vector diagram shows clearly the eddy area and gas flow change by overfire air jet. The mixing index, which is defined by overlap of path lines, evaluates the relative effects of the overfire air jet based on the number of nozzles, location of the nozzles and the air flow rate.

Experimental data of the path line and velocity vector make it possible to evaluate the effectiveness of computer simulation of the gas flow pattern in the chamber.

Key words: municipal solid waste incinerator, cold model, visualization, path line diagram, velocity vector