Depart ent of a1emical Engineeri ng Universit y of Thessalon iki , GreeceThe us e of slurry-so lids fluid beds plays an important role in the developme nt of synthetic fuels and the hydrogen processin g of petroleum resids. In the H-Coa l process in particula r , coal oil slurries are processed over extrudate s of hydrodes ulfurizati on catalyst . The ob j ective of this note is to present a model uhich describes the volume frac~ion occupied by the slurry phase . The accurate predictio n of the liquid holdup is important not only for the calculati on of the bed height in liquid solid fluidized beds, but also is required for the developme nt of a model predictin g the holdu p i n three-pha se flui di zed beds.Although several correlatio ns have been considere d in the literatur e ( Richardso n and Zaki , Ramamurth y and Sabbaraju ) for pure liquids, ver y l itt le ha s been publis hed for slurry systems. The bjective of this paper i s to extend the work of previous investiga tors for systems of particula r interest to the H-Coal proce ss . A summary of correlati ons describin g liquid-so lid fluidi zed bed s has been presented elsewhere (Vasalos , et al ., 1979(Vasalos , et al ., , 1980. In the present publicati on , the applicati on of t wo correlati ons is considere d: 1) the Richardso n nd Z ki; nd 2) Ramnmurth y and Sabbaraju . The first relates the liquid volume fraction ( £1) due to bed expansion to the rati o of t he superfic i al velocity ( Ut) to the terminal veloc ity of a single particle

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DISCLAIMERPortions of this document may be illegible in electronic image products. Images are produced from the best available original document. ~~~w m p r r p e m d~a a~t o f a r o r L l r p o n r o t c d b y a n~~a f~U a i t c d S t a t mGmmucnt. Neither tW UM-&t*s G c m m d ilhr my e y thorod, aor any of cntplopm, &a any warranty, qmss or implied, or assumes any l& hbany or -1-bility far the auxuacyt compbtcaoaq or P u a W of m y infomdiao, a-taa, product, or p r o c e a s d i s d o s e d , a r~t s W i t a u w w o n l d n o t i a f~~~t e l y c r w n e d~R e f e r~~t o a n y~c a n n m e r o i s l p r O a u c t . p p g~g q~~b y t r a d c 8 s n r c ,~a r k , maad-,or or doel not ncca&ly nceora~rllytitutltate or imply i e a t , feum- mendation, or favoring by the United States Gimmmmt or any agency t h u d . The views a w l o p i a i o m o f a~m c x p r r ; r a s d h c r t i n d o w t~y s 4 a t c o r n R c c t t h o e c o f t h e United Statas Govemmtrtt ot any agancy t h M .This report has been reproduced directly from the best availabk copy. 252 STUDY OF EBULLATED BED FLUID DYNAMICSFINAL PROGRESS REPORT . SEPTEMBER, 1980, TO JULY, 1983 The fluid dynamics occurring in HRI's H-coal process development unit (PDU) coal liquefaction reactor during Run PDU-10 were measured and compared with Amoco Oil cold-flow fluidization results. It was found that catalyst bed expansions and gas holdups are higher in the PDU than those ob.served in the cold-flow tests for slurries having the same nominal viscosity. Comparison of PDU results with cold-flow results shows that the bulk of the operating reactor gas flow lies in the ideal bubbly regime. It also appears that the gas bubbles in these PDU tests are .rising quite slowly. Only two of the operating points in our test program on the PDU were found to lie in the churn turbulent regime. Existence of churn turbulent behavior during these two experiments is consistent with trends observed in earlier cold-flow experiments.Two-and three-phase fluidization experiments were carried out in Amoco's cold-f low fluid dynamics .unit. The data base now includes fluidization results for coal charlkerosene slurry concentrations of 4.0, 9.8, and 20.7 vol% in addition to the 15.5 and 17.8 vol% data from our earlier work. Both HDS-2A and Amocat-1A catalysts were used in the tests. Bed expansion is primarily a function of slurry velocity, with gas velocity having on1y.a weak effect. Bed contractions have been observed in some cases at sufficiently high gas velocity. Gas and liquid holdups were found to be uniform across'the cross-section of the Amoco cold-flow fluid dynamics pilot plant.A viscometer was adapted for measurement of the viscosity of coal slurries at high temperature and pressure. Three techniques were developed for the study of the bubble dynamics occurring in three-phase fluidized beds: 1) A laser light beam probe for measuring the behavior of bubbles greater than 120 microns; 2) A laser holographic technique for determining the size, shape, and position of bubbles in the bed;...

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