Main entry under title: Gas fluidization technology. ‘A Wiley-Interscience publication.’ Includes index. 1. Fluidization. I. Geldart, D, TPF65G37 ISBN 0. permission of the publisher. Gas fluidization technology. ‘A Wiley-Interscience publication.’ Includes index. 1. Fluidization. I. Geldart, D, TPF65G37 Powder Technology The behaviour of solids fluidized by gases falls into four clearly recognizable groups, characterized by density difference (ϱs–ϱf) and mean D. Geldart. Powder Technol., 6 (), p. 2. R.H. Wilhelm, M. Kwauk .
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Provided that the diameter or width of the perforations is less than about ten particle diameters, littie ‘weeping’ of solids occurs.
Gas Fluidization Technology – Google Books
Share your thoughts with other customers. Interphase gas convectIve compo? Geldart, D, ,2′ TP Fundamentals of Fluidized-bed Chemical Processes, Butterworths. KeairnsCambridge University Press, p. When the gas enters the bed vertically, the jet penetration determines the lowest level at which surfaces such as heat exchange tubes should be located, and imposes a lower limit on operating bed depth.
It is conceivable that bed operating conditions exist under which it is possible to have effectively slow bubbling behaviour in the lower bed regions but fast bubbling higher within the bed with consequent implications for bed-to-surface heat transfer. In Fluidization Technology Ed.
Gas fluidization technology ( edition) | Open Library
Tracer and optical transit methods seem most appropriate, although the latter requires the use of electronic signal processing. Joint Meeting of Chern. Note that the Jones and Leung analysis resulted in a different ‘best’ correlation for USal1 than did the Arastoopour et al.
This is discussed further in Chapter 3. However, when there is no background gas flow – the case of common practical interest – a gas jet forms. Normally this requirement imposes no further restriction on ti. Umf can be calculated from the Wen-Yu equation which slightly over-estimates at temperatureEq. The gas flow condition through the bed is then turbulent or at least in the transitional flow regime.
From Merry’s correlation, Eq. The final technloogy between horizontal or vertical tube arrangements would seem to depend largely upon constructional convenience – how best to introduce the tubes into the bed, support them, and allow for thermal expansion.
Gas Fluidization Technology
A worked example of how to calculate the saltation velocity using the Zenz correlation is shown below. This is reasonable because there will be little change in the actual gas flow conditions through the continuous phase or adjacent to the transfer surface with group 0 bubbling beds and, indeed, the maximum bed-to-surface coefficient is relatively insensitive to further increase in fluidizing gas velocity, though some allowance should be made for direct heat transfer between the gas flowing through the bubbles and the transfer surface Catipovic et aI, This arrangement is also suitable if more than one gas stream is to be introduced to the bed without premixing.
For an initial estimate, Eq. E 0 Figure 9.
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Use of fluid beds for ethylene oxide production and ethanol dehydration does not appear to have progressed beyond the pilot plant stage, and although the Mobil methanol-to-gasoline process has recently been demonstrated to be a technological success Penick, Lee and Mazink,currently the economics are attractive in only a few countries. The use of a stirred bed Brekken, Lancaster, and Wheelock, achieves satisfactory mixing of strongly cohesive powders due to constant breakdown of any channels formed near the distributor.
Model and empirical equations for mixing, as developed above, enable the designer to estimate those operating conditions which yield the required particle circulation.
Paper presented at Soc. Air at K and 1. If operation with a range of gas rates is anticipated, the distributor should be designed to give sufficient pressure drop at the lowest gas rate technoloyy. Probes inevitably cause some local disturbance in fluidized beds.
Frame-by-frame analysis of bubble properties presents some special problems, especially when the flow due to translation of bubbles is measured Grace and Clift, There is a greater tendency for particles to salt out in a horizontal pipe which is preceded by a downflowing vertical-to horizontal technollgy than in any other configuration Patterson, Hence the lower and upper limits on b may be taken as: Gunn and AI-Doori found that proper signal processing and noise discrimination were of critical importance in obtaining accurate data from probes.
Caution is clearly required in the use of probe data.
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