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Show Table 1. Chemical analysis of Kentucky No. 9 coal Nominal Approximate range Proximate analysis (dry basis) % VM % Ash % Fixed carbon Gross heating value (Btu/lb, moisture free) Ultimate analysis (dry basis) % Carbon % Hydrogen % Nitrogen % Oxygen (by diff.) % Total sulfur 36.7 14.0 49.3 29-40 8-25 42-52 12,000' 11,000-13,500 67.8 4.8 1.9 7.3 4.2 63-75 4.3-5.2 1.0-2.5 3.0-10.0 3.6-4.5 a2.788 x 104 kJ/kg. b2.556 x 104 - 3.137 x 104 kJ/kg, DISCUSSION OF RESULTS The Mass-Transfer Correlation The results of the mass-transfer experiments with naphthalene are depicted in Fig. 5. The measured Sherwood numbers appear to agree quite well with the predictions of the correlation originally proposed by Frossling (13) for a single sphere suspended in a uniformly flowing fluid. This correlation is 1/2 1/3 Sh = 2.0 + 0.60 Re ' S ' P c The modified correlation developed by Ranz and Marshall (14) predicts slightly higher Sherwood numbers, as it uses a coefficient 1/2 1/3 of 0.69 instead of 0.60 for Re S . For this reason the Ranz- P c Marshall correlation does not fit the data quite as well as the Frossling correlation. In spite of the slight differences in the correlations, the entrance effects and flow disturbances in the tubular reactor appeared to have a minimal effect on mass transfer. Thus the Frossling correlation was used to estimate the external (ID 16 |