Erosion rates and patterns of the hygas pilot plant's effluent cyclone

The high-pressure effluent gas cyclone in the HYGAS substitute natural gas process has removed about 1350 tons (1225 metric tons) of solids, predominantly spent char, ash and coal fines of less than .8 mm in size, from the raw product gas stream, to date. Various rates and patterns of erosion have been found in different regions of the cyclone. On the inlet wall a stellite 6B region is eroding at a rate of about 6 mils/100 tons (.15 mm/90.7 metric tons) of solids removed. A comparable region of 304 stainless steel (SS) is wearing at a rate three times that of the stellite. An Incoloy 800 liner in the solids discharge nozzle, whose inside radius is one-third that of the inlet wall, is eroding at a rate 2-1/2 times that of the 304 SS inlet wall and seven times that of the stellite. Previously, a 316 SS nozzle wore at a rate twice that of the 304 SS inlet wall. Gouging and longitudinal sawtooth wave erosion patterns found on the cyclone's 316 SS internal cone, as well as on the Incoloy 800 liner, are indicative of regular (possibly even resonant) solids movement.