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Show The kiln used for these tests was four feet in diameter and fifteen feet long. The kiln was set up to feed liquid, sludge, and solid waste on a continuous basis. Sludge was pumped into the kiln using an air operated diaphragm pump. Liquid waste was atomized through a burner, and packaged trash was ram fed into the kiln. Natural Gas was used as auxiliary fuel. Ash exited the kiln into a wet trough. Ash was removed from the trough by a mechaincal conveyor. Flue gas exited the kiln and was ducted to a secondary combustion chamber (See). The see had was approximately four feet inner diameter and ten feet long. The facility was equipped with a venturi type wet scrubbing system that removed particulate and acid gases. A schematic of the test facility is shown in Figure I. 2.0 Experimental The primary concern with rotary kiln destruction of biological sludge was process viabiltYi would the sludge disperse in the kiln, or would "sludge balls" be formed? "Sludge Balls" are spherical pieces of sludge that have been incinerated on the outside, but contain raw sludge on inside. The ash from the burnt sludge provides an insulating layer around the core of unprocessed sludge. These balls rollout of the kiln without being incinerated. Three operating scenarios were tested. Tests 1A and 1B were run on sludge using natural gas for fuel. No other waste was fed to the kiln. This test was performed to establish baseline emissions data. Tests 2A and 2B were run on sludge and liquid waste. The blended liquid waste was used to represent the variety of liquid waste produced by the elBA-GEIGY McIntosh plant. The ratio of liquid to sludge fired reflects the predicted ratio of liquid to sludge effluent to be produced by the McIntosh plant in 1991. The ultimate analysis of the liquid waste can be found in Table I. Test 3A was run on sludge, blended liquid, and packaged waste. The package waste was obtained from an operating unit at the McIntosh Plant. It consisted of a wet filter cake contaminated with ppm levels of solvents. The filter cake itself is a cellulosic material. The filter cake was placed inside clear plastic bags. Each bag contained between four and six pounds of filter cake. This waste was chosen to represent McIntosh packaged waste due to its availabilty, ultimate analysis, and past problems encountered with its disposal. This waste had a tendency to promote the formation of slag dams in a full scale kiln. An ultimate analysis for this waste can be found in Table I. 3 |