Kunii

D. Kunii and O. Levenspiel, Fluidicyation Engineering Krieger Publishing, New York, 1977, p. 18. 

Glaser and Thodos [Am. Jn.st. Chem. Eng. J., 4, 63 (1958)] give a correlation involving individual particle shape and bed porosity. Kunii and Suzuki [Jnt. ]. Heat Mass Tran.sfer, 10, 845 (1967)] discuss heat and mass transfer in packed beds of fine particles. 

In the irreversible limit R < 0.1), the adsorption front within the particle approaches a shock transition separating an inner core into which the adsorbate has not yet penetrated from an outer layer in which the adsorbed phase concentration is uniform at the saturation value. The dynamics of this process is described approximately by the shrinldng-core model [Yagi and Kunii, Chem. Eng. (Japan), 19, 500 (1955)]. For an infinite fluid volume, the solution is ... 

For details beyond the scope of this subsection, reference should be made to Kunii and Levenspiel, Fluidization Engineering, 2d ed., But-terworth Heinemann, Boston, 1991 Pell, Gas Fluidization, Elsevier, New York, 1990 D. Geldart (ed.). Gas Fluidization Technology, Whey, New York, 1986 and the vast number of papers published in periodicals, transcripts of symposia, and the American Institute of Chemical Engineers symposium series. 

The bubble model (Kunii and Levenspiel, Fluidization Engineering, Wiley, New York, 1969 Fig. 17-14) assumes constant-sized bubbles (effective bubble size d ) rising through the suspension phase. Gas is transferred from the bubble void to the mantle and wake at... 

FIG. 17-14 Biihhling-hed model of Kunii and Levenspiel. dy = effective hiih-ble diameter, = concentration of A in hiihhle, = concentration of A in cloud, = concentration of A in emulsion, y = volumetric gas flow into or out of hiihhle, ky,- = mass-transfer coefficient between bubble and cloud, and k,. = mass-transfer coefficient between cloud and emulsion. (From Kunii and Leoen-spiel, Fluidization Engineering, Wiley, New York, 1.96.9, and Ktieger, Malahar, Fla., 1977.)... 

Yagi, S. and D. Kunii, 1963, Proc. Heat Transfer Conference, University of Colorado 1959 and London 1962, p. 750. 

A wide range of particle terminal velocities for various Reynolds numbers have been investigated by Kunii and Levenspiel.43 They suggested that if the particles were assumed to be spherical and operated at low particle Reynolds number (Rep < 0.4), the Stokes equation was found to be acceptable (see Figure 17.4). Therefore, the terminal velocity Ut can be expressed as ... 

Kunii, D. and Levenspiel, O., Fluidisation Engineering . John Wiley and Sons, New York, 1969. 

Daizo Kunii, Octave Levenspiel, Fluidization Engineering second edition, (1991). 

In spite of the drawbacks enumerated above, fluidized bed reactors have a number of compelling advantages, as we have noted previously. By proper design it is possible to overcome their deficiencies so that their advantages predominate. This book does not discuss in detail the manner in which this problem can be solved, although the design considerations outlined in subsequent sections of this chapter are quite pertinent. For detailed treatments of fluidized bed reactor design, consult the excellent reference works by Kunii and Levenspiel (3) and by Davidson and Harrison (4). 

Heat transfer in packed beds. Effective thermal conductivity as a function of Reynolds number. Curve 1 Coberly and Marshall. Curve 2 Campbell and Huntington. Curve 3 Calderbank and Pogorski. Curve 4 Kwong and Smith. Curve 5 Kunii and Smith. (From G. F. Froment, Chemical Reaction Engineering, Adv. Chem. Ser., 109, 1970.)... 

Basic two-phase model of fluidized bed. Open arrows indicate movement of solids. (Adapted from Fluidization Engineering by D. Kunii and O. Levenspiel. Copyright 1969. Reprinted by permission of John Wiley and Sons, Inc.)... 

Morimoto K, Kawabata K, Kunii S, Hamano K, Saito T, Tonomura B (2009) Characterization of type I collagen fibril formation using thioflavin T fluorescent dye. J Biochem 145(5) 677... 

Figure 5. Effect of system pressure on heat transfer in bubbling fluidized bed. Data of Bock and Schweinzer, 1986, as adapted by Kunii and Levenspiel, 1991.)...

Figure 6. Effect of bed temperature on heat transfer coefficient for bubbling bed of ceramic particles. (Data of Yoshida, Ueno and Kunii, 1974.)...

Figure 10. Fluidization regimes, adapted from Grace (1986) by Kunii and Levenspiel (1991) particles labeled by Geldart Classifications A, B, D.

Yagi, S., and Kunii, K., Studies on Effective Thermal Conductivities in Packed Beds, AIChE J., 3 373 (1957)... 

Downcomer Pressure Drop. When the downcomer is less than minimally fluidized, the pressure drop can be estimated with a modified Ergun equation substituting gas-solid slip velocities for gas velocities (Yoon and Kunii, 1970), as shown in Eq. (9). 

Judd, M. R., Masson, H., and Meihack, W., Solid Circulation and Gasification Experiments in a Fluidized Bed with a Draft Tube, Fluidization, (D. Kunii, and R. Toei, eds.), Engineering Foundation, New York, pp. 663 (1984)... 

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