Pressure Drop in Flow of Dense Coal-Air Mixtures

Albright, C. W.; Holden, J.H.; Simons, H. P.; Schmidt, L.D.

doi:10.1021/ie50500a044

Cited by 14 publications

(5 citation statements)

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“…The relationship between k,/ki and fractional void c is shown is shown in Figure 10. Wyllie (16) mentioned that the following equations can be used: Archie's equation (1) F = e-1 (10) Slawinski's equation ( I S ) F = (1.3219 -0.3219~))'" (11) where F equals I/c. Khen the fractional void is small, Equation (10) can be applied.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Effective diffusivity of packed bed

1959

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= pipe diameter ( L ) .# 9 = gravitational acceleration (LO-$) G , = gas mass velocity in pipes G . = solid mass velocity in pipes X = constant for a given particle size L = length of the transport line (L) R = solids to gas mtio (no dimension) C, = average linear velocity of gas = average linear velocity of solid particles (LO-1) = total volume of solid and gas collected in the receiver (L3) = weight of gas (111) = weight of solid (-11) = cross-sectional area, of agglomerated mass of flow in pipe (D) = drag coefficient (no dimension) = average particle diameter (L) = friction factor (no dimension) (m-Ze-1) ( m -2 e -i ) (Le-1) L- If- Greek LettersAPas = pressure drop due to avceleration of gas (FL-2) APa8 = pressure drop due to acceleration of solid particles AP, = pressure-drop due to body drag IFL-2)AP, = pressure drop due to friction Apt = total pressure drop (FL-2) A U = slip velocity between gas and solid particles (LO-1) p-. = density of gas (ML-3) pdo = dispersed gas density (ML-3) pds = dispersed solid density (ML-3) p1 = solid particle density (ML-3) (FL-2) From time to time, A.1.Ch.E. Journal presents translations of certain technical articles written by our Japanese colleagues in their own language. These translations are made by Kenzi Etani, who received his B.S. in chemical engineering in 1953 at the Tokyo Institute of Technology and his M.S. in 1955 at M.I.T. He is associated with Stone & Webster and is an associate member of American Institute of Chemical Engineers. He is also a member of the Society of Chemical Engineers, Japan, and the Japan Oil Chemists' Society. His offer to help break down the language barrier is acknowledged. appear in English in the original paper. No figures will be reproduced in these translations. (1957). 2 between the concentration radient at the liquid surface and time would be Abstracts, notation, literature cited, tables, and figure captions not published here The foBlowing article was published in Chemical Engineering (Japan), 21, pages 17-25 3-0 = _ _ 2 [ e -( r / 2 ) * r + e-9\*/3)'r (3)The purpose of this experiment was to obtain the relation between effective diffusiyity and fractional voids under nonflowing conditions. The results were compared with electric conductivity. APPARATUS AND EXPERIMENTThe apparatus used in this experiment is shown in Figure 1. The diameters of the tubes were 3.50 and 3.05 cm. The height of the packed bed was changed from 5 to 15 cm. All apparatus was kept at the constant temperature of 40 =t 0.2"C. in a constant-temperature bath. Air having the same temperature was introduced a t the top of the packed bed a t the constant velocity of 55 cc./sec. Packing materials used were lead shot, ordinary sand, and crushed calcite. Diffusing materials used were bennene and water.Bfter the equipment had been immersed for 30 to 60 min. in We constant-temperatiwe bath, air was introduced. Prior to the introduction of air, water or benzene diffuses upward and reaches the saturated state. This diffusion is expres3ed by the following basic equation: !...

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Section: Resultsmentioning

confidence: 99%

“…The use of the relaxation method for numerical solutions of engineering problems was pioneered by Southwell (1). (See also references 4 to 7.)…”

Section: John S Thomsen Rho Johns Hopkins University Baltimore Marmentioning

confidence: 99%

Effective diffusivity of packed bed

1959

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“…Although there may be other ways of classifying both groups of variables, a convenient method of classifying them from a practical operating standpoint is as follows: I. Independent process variables (operating variables) 1. Shape and dimensions of gasifier (design) 2.…”

Section: Heat Effects and Reaction Ratesmentioning

confidence: 99%

Pilot Plants-POWDERED-COAL GASIFICATION. Effect of Variables

Sebastian¹

1952

Ind. Eng. Chem.

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P ment in oxygen and superheated steam are being developed in small and large pilot plants a t the Morgantown, W. Va., Station of the Bureau of Mines, U. S. Department of the Interior, under a cooperative agreement with West Virginia University.The initial work of development and operating results obtained as progressive improvements advanced the project toward the solution of many hitherto unknown problems have been d e scribed from time to time in the literature (1,3,(8)(9)(10)(11).From the start it was realized that, since there are enormous differences in chemical and petrographic composition as well as chemical and physical properties of the many varieties, ranks, and grades of coals in the United States, there would be strong necessity for a practical laboratory scale method to test various fuels for their utility in synthesis-gas production. Accordingly, a laboratory scale method was developed for the continuous production of synthesis-gas (essentially CO + Hz) by entrainment of powdered coals in oxygen and superheated steam. The laboratory scale pilot plant, which gasifies various types of fuels a t rates up to 55 pounds per hour, has been in operation for about 4 years (IO) and has furnished design data for building considerably larger pilot plants. Principally, however, the information obtained in testing various types and grades of coals served as a guide to operating conditions for other, larger scale gasifiers at the Morgantown Station. The suitability of the coal for synthesisgas production on commercial basis was thus determined.It soon became evident that all coals do not gasify alike in a generator of given design but differ vastly in their behavior, and coals that appear to give the worst results are frequently available in given localities at the lowest price. It was desirable, therefore, that an investigation of the effects of process variables should determine under what conditions a given coal can be gasified with maximum efficiency, lowest oxygen and steam requirement, and, hence, lowest cost. In the work described, an attempt was made to approach this objective by analyzing the independent and dependent process variables and to determine the effects of the former on the latter. The respective significance of each is discussed.EQUIPMENT AND PROCEDURE Figure 1 shows that the apparatus consists of ( a ) pneumatic feeding system, ( b ) gasifier, ( c ) residual dust-removal system, and ( d ) auxiliaries (condensers, exhauster meter, storage tank, vent pipe, and instrument-control system). Pictures of the labore tory scale pilot plant are shown in Figures 2 and 3, representing the upper and lower floors, with the gasifier, next to the control board on the upper floor, extending to the floor below. Details ~ of construction of various parts of the unit, including the gasifier, have been given in two Bureau of Mines' reports, one of which has already been ublished (IO).Pulverized coa]Pis fed continuously, at rates up to 55 pounds per hour, int.0 the top of the gasifier from the continuous feeder c...

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“…Flow data and pressure drops accompanying the transport of dense coal-air mixtures through pipes were reported by Albright el al. (4). A preliminary correlation in terms of modified friction factors was proposed.…”

Section: Flow Through Apparatusmentioning

confidence: 99%