Chilton-Colburn relation

The temperature difference is thus directly proportional to the heat of reaction per mole of diffusing species and to the difference in concentration between the bulk fluid and the exterior surface of the solid. If we recognize that jD jH from the Chilton-Colburn relation, and that the ratio of Prandtl and Schmidt numbers is close to unity for many simple gas mixtures, the previous relation may be approximated as... 

For turbulent flow, we shall use the Chilton-Colburn analogy [12] to derive an expression for mass transfer to the spherical surface. This analogy is based on an investigation of heat and mass transfer to a flat plate situated in a uniform flow stream. At high Schmidt numbers, the local mass transfer rate is related to the local wall shear stress by... 

The Chilton-Colburn analogy can be also used to estimate the local mass transfer rate in laminar flow where the wall shear stress is related to the azimuthal velocity gradient by... 

The Chilton-Colburn analogy has been obserx ed to hold quite well in laminar or turbulent flow over plane surfaces. But this is not always the case for internal flow and flow over irregular geometries, and in such cases specific relations developed should be used. When dealing with flow over blunt bodies, it is important to note that/in these relations is the skin friction coefficient, not the total drag coefficient, which also includes tlie pressure drag. 

Each of the modified Re3molds analogy relations (5.237) and (5.238) includes an additional Sc and Pr dependency, respectively. These relationships are often referred to as the Chilton-Colburn analogies [20, 60] (p 364). 

The heat and mass transfer coefficients are related by the so-called Chilton-Colburn analogy (see, for example, [8]) ... 

For turbulent flow in pipes the mass transport coefficient and the friction coefficient are related by the Chilton-Colburn analogy ... 

Chilton-Colburn analogy A widely used analogy from heat momentum, and mass transfer analogies. Also known as -factors, they are used to determine an unknown transfer coefficient when one of the other coefficients is known. It applies to fully developed turbulent flow in pipes, and relates mass and heat transfer coefficients, and friction factors. It was proposed by and named after American chemical engineers Thomas H. Chilton (1899-1973) and Allan P. Colburn (1904-55). 

The proposals made for calculating transfer coefficients from physical data of the system and the liquid and vapour rates are all related to conditions existing in a simpler unit in the form of a wetted-wall column. In the wetted-wall column, discussed in Chapter 12, vapour rising from the boiler passes up the column which is lagged to prevent heat loss. The liquid flows down the walls, and it thus provides the simplest form of equipment giving countercurrent flow. The mass transfer in the unit may be expressed by means of the j-factor of Chilton and Colburn which is discussed in Volume 1, Chapter 10. Thus ... 

The Reynolds analogy is a very useful relation, and it is certainly desirable to extend it to a wider range of Pr and Sc numbers. Several attempts have been made in this regard, but the simplest and the best known is the one suggested by Chilton and Colburn in 1934 as... 

This relation is usually called after Chilton and Colburn. For smooth circular channels,... 

This conceptually simple and elegant approach to the design of continuous differential contacting mass transfer equipment was first developed by Chilton and Colburn in the early 1930s. It enables us to establish the height of a packed column by multiplying a number related to the mass transfer capability of the equipment, the HTU, by a dimensionless number, the NTU, which is closely related to the number of theoretical stages. The HTU or Ka values must be btained from literature tabulations, experimental data, or correlations. Partic-alar care must be exercised to assure that the dimensionless NTU used is compatible with the particular HTU. For example, in Perry s Handbook, fifth... 

A rapid graphical method, related to the McCabe-Thiele procedure, has been described by Chilton and Colburn [163]. It is applicable to all mixtures for which the equilibrium curve is known. The operating line should, however, not lie too close to the equilibrium curve in the range considered. The operating line is constructed in the usual way in the equilibrium diagram, and through the point Xb a vertical line is... 

Evaluation of the heat flux due to mass transfer can be simplified by using the mass diffusion coefficient K obtained from the Chilton and Colburn equation. However, not all the mass transfer predicted by the relation KgM X (P -P )... 

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