Evidence for a rich flammability limit is presented for pulverized Pittsburgh seam coal (36% volatiles, 56.1% fixed carbon, 50 μm mass mean particle diameter). Experiments were conducted in a large (0.3 m diam by 4.5 m long) horizontal tube that generated a vertical dust concentration gradient for the rich mixtures. Horizontally propagating steady state flames were observed only in regions where the concentration was below 1.5 kg/m3. When the location where the dust concentration exceeded 1.5 kg/m3 was varied, the edge of the visible flame front moved accordingly. This is interpreted as evidence for a rich limit of 1.5 kg/m3 for this coal.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Physics and Astronomy(all)