A series of high-pressure pneumatic dense-phase flow experiments were conducted using pulverized coal as the granular solids. This granular material was transported by nitrogen gas out of a conical feeder tank, through a length of stainless-steel tubing and into a pressurized receiver tank. Only the nitrogen gas trapped in the interstices of the coal particles inside the feeder tank was used to transport the coal. Six different transport stainlesssteel tube geometries were used.A detailed analysis of the system is performed. This analysis reasonably predicts the expected solids flow rate for a given set of operating conditions and the minimum pressure drop required to maintain flow. K. M. SPROUSE SCOPEPneumatic conveying of pulverized solids is an extremely interesting field of study. Many different types of transport systems have been developed for commercial use as described by Kraus (1980). Perhaps the most reliable technique for conveying bulk materials is the dilute-phase transport method which mechanically feeds granular solids into a high-velocity gas stream. This highly turbulent gas stream rapidly entrains the particles and prevents them from settling out as the solids are transported over a given distance.Dilute-phase transport is characterized to a great degree by extremely high gas to solids volume conveying ratios and low gas pressure drops. For many applications, these high volume ratios are not desirable due to restrictions on feed system size, gas compressor or blower power requirements, or the amount of carrier gas allowed for conveying. In response to these restrictions, commercial systems are now available which significantly reduce the gas to solids volume ratio. The trade-off that occurs by reducing the transport volume ratio is that the gas pressure drop across the feed line is significantly raised, and since the solid particles are in much closer contact with one another, the chances of plugging the feed line are greatly increased. Wen and O'Brien (1976) and Klinzing (1981) have reviewed the types of analyses and experimental studies which have been used in designing both dilutephase transport systems and those using lower gas to solids volume ratios. They have indicated that by lowering the volume ratio, a flow condition will be reached whereby the solids will begin to separate out from the main gas stream and flow in a nonuniform condition. This flow regime has been defined as dense-phase solids transport. However, once the volume ratio has been reduced to the point where the entire transport line is filled with granular material at or near its static bed void fraction, Wen and OBrien (1976) and Klinzing (1981) indicate that the pipe will plug, thus terminating flow.Experimental efforts by Burge et al. this is not necessarily true with proper feed system design. Reliable dense-phase feeding in uniform plug flow can be maintained by keeping inside pipe walls smooth with no sudden cross-sectional area contractions or expansions and by providing sufficient gas pressure drop through the f...

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A detailed description of pulverized coal conversion in one‐dimensional entrained flows has been formulated and correlated to hydrogasification data from the Rockwell International Flash Hydropyrolysis (FHP) reactor using bituminous coals. This analysis contains physical and chemical descriptions which have not been included in previous mathematical models. These descriptions provide further important insights into the nature of entrained flow coal gasification.

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C Cr ro os ss s-R Ro ol ll l F Fl lo ow w F Fo or rm mi in ng g o of f O OD DS S A Al ll lo oy y H He ea at t E Ex xc ch ha an ng ge er r T Tu ub be es s F Fo or r H Ho oo op p C Cr re ee ep p E En nh ha an nc ce em me en nt t Quarterly Technical Progress Report