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Show flame stabilization as shown in Fig. 4. A propane feed line was installed to allow preheating the refractory in a non-pulse mode, to reduce noise problems. The first tests were carried out with a low density refractory liner in the can, but it did not survive well in the pulsing environment, so the liner was recast with a high density refractory, which showed no signs of fatigue in subsequent runs. 2.4 Instrumentation Pressure oscillations were measured using Kistler piezoelectric pressure transducers mounted on water cooled legs off the pulse combustor and tailpipe. The voltage outputs from the pressure transducers were also used to trigger the flash unit for the photographic studies. 2.5 Photographic System Photos were taken with a 35 mm camera with macro lens using 400 ASA black and white film. The flash was an EG&G Electro-optics Microflash system, modified to provide delays of up to 7 ms after the trigger pulse. The shutter was held open just before a flash was to occur and closed immediately afterward. The flash duration was 0.5 microseconds, essentially freezing the atomization and flow processes. 3. RESULTS 3.1 Combustion Tests Initial combustion tests were aimed at demonstrating proof of concept. Provision has been made for sampling the coal aerosol following the initial tests, but the current investigation sought to demonstrate a reliable slurry flame could be attached downstream of the pulse combustor. The unknown effects of pulsating flow on flame stability prompted some concern that a steady CWS flame could be attached in a reasonable combustor volume. The |