Glass for modeling the deposition of coal ash in hot cyclones

Tests have been conducted in a laboratory hot cyclone to obtain an estimate of the temperature below which spherical glass particles do not form a firmly attached deposit. A temperature of 800/sup 0/ to 850/sup 0/C, corresponding to a viscosity between 6.3 x 10/sup 5/ and 2.9 x 10/sup 6/ poises, as calculated from the composition of the glass, was found. We take this viscosity to be approximately that of coal ash above which particles will not deposit in cyclones of fluidized-bed coal gasifiers. 6 references, 2 figures.