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*Values listed are for moderate nonproximity agitation. CS = carbon steel.
*Values listed are for moderate nonproximity agitation. CS = carbon steel.
In Eqs. (1153a) and (1153&), NRe is based on particle diameter and superficial fluid velocity.
Zenz and Othmer (see "Introduction: General References") give an excellent summary of fluidized bedtowall heattransfer investigations.
Solidification involves heavy heat loads transferred essentially at a steady temperature difference. It also involves the varying values of liquid and solidphase thickness and thermal diffusivity. When these are substantial and/or in the case of a liquid flowing over a changing solid layer interface, Siegel and Savino (ASME Paper 67WA/Ht34, November 1967) offer equations and charts for prediction of the layergrowth time. For solidification (or melting) of a slab or a semiinfinite bar, initially at its transition temperature, the position of the interface is given by the onedimensional Newmann's solution given in Carslaw and Jaeger (Conduction of Heat in Solids, Clarendon Press, Oxford, 1959).
Later work by Hashem and Sliepcevich [Chem. Eng. Prog., 63, Symp. Ser. 79, 35, 42 (1967)] offers more accurate secondorder finitedifference equations.
The heattransfer rate is found to be substantially higher under conditions of agitation. The heat transfer is usually said to occur by com
TABLE 118 External Coils; Typical Overall Coefficients*
TABLE 118 External Coils; Typical Overall Coefficients*
Type of coil 
Coil spacing, in.T 
Fluid in coil 
range, °F. 
m without cement 
U with heattransfer cement 
r in. o.d. copper tubing attached 

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