Transfer coefficient data

Extrapolation of KgO data for absorption and stripping to conditions other than those for which the origin measurements were made can be extremely risky, especially in systems involving chemical reactions in the liquid phase. One therefore would be wise to restrict the use of overall volumetric mass-transfer-coefficient data to conditions not too far removed from those employed in the actual tests. The most reh-able data for this purpose would be those obtained from an operating commercial unit of similar design. 

Fig. 6.31 Comparison of R-134a heat transfer coefficient data with predictions based on Chen (1966), Shah (1982), Lazarek and Black (1982), Liu and Winterton (1991), Tran et al. (1996), Lee et al. (2001b), Yu et al. (2002) and Warrier et al. (2002). Reprinted from Lee and Mudawar (2005b) with permission...

Fig. 6.32 Comparison of heat transfer coefficient data for R-134s and water with predictions based on Lee and Mudawar correlation. Reprinted from Lee and Mudawar (2005b) with permission...

Figure 4. Effect ofmixed particle sizes, (a) Particle size distribution, (b) Circumferential-average heat transfer coefficients. (Data ofBiyikli and Chen, 1982).

Of the parameters making up the Hatta number, liquid diffusivity and mass-transfer coefficient data and measurement methods are well reviewed in the literature. 

The results shown in Fig. 7 indicate that kLaL increases with pressure. On the other hand, for aqueous systems, Albal et al. (1983) showed both kLaL and kL to be independent of pressure. These investigators also showed that kLaL decreases with an increase in viscosity and increases with a decrease in surface tension. The mass-transfer coefficient data for oxygen-CMC-water and oxygen-water-Triton CF-32 were correlated by the dimensionless equation... 

For gas-liquid-solid systems, studies on gas-liquid and liquid-solid mass transfer in basket reactors have been rather limited. For the rotating basket reactor, gas-liquid mass-transfer coefficient data are needed. Liquid-solid mass transfer has been studied by Teshima and Ohashi (1977), and their data are correlated by... 

Transfer coefficient data could be subsetted from a re-entry database based on the anticipated label-specified clothing, or the appropriate TC data for specific body areas could be adjusted by a generic clothing penetration factor (see... 

Cummings and West (Cll) extended the earlier work of Chilton et al. to a larger vessel and some different impellers. They obtained essentially the same correlations and also showed that their correlation for helical coil heat transfer was adequate to correlate the data of Rushton et al. (R15) for vertical baffle-coils. With a few scattered data, Cummings and West also indicate that changing the direction of rotation of their pitched-blade turbine had no significant effect on the heat-transfer coefficients. Data by Kraussold (K9), from a vessel in which a paddle with a very high ratio of blade width to diameter was used, also confirm the correlations of Chilton et al. 

Figure 7 presents the heat transfer coefficient data, which correspond to the center of the long side of the channel. The distance from the test section inlet equals 0.22 m. In these experiments the... 

Figure 8 presents the heat transfer coefficient data for the corner of the test section. The circles in Figs. 7, 8 correspond to the calculated heat transfer for non-uniform liquid film thickness, which agree well with the data both for large and small liquid Reynolds numbers. In these calculations the temperature of the outer wall and the heat transfer coefficients were defined in accordance with the experimental procedure. The calculations show that liquid suction occurs toward to the channel s corner and liquid is therefore non-uniformly distributed along the perimeter. 

A check on the column height may be carried out based on mass transfer rate. This requires the availability of mass transfer coefficient data. Depending on appropriate assumptions. Equation 15.22 or 15.24, or their equivalent counterparts may then be used to calculate the column height, as discussed in Section 15.3. 

For fully developed turbulent planar jets issuing from a parallel plate channel and impinging on an isoflux surface, Wolf et al. [103] correlated their local heat transfer coefficient data for water jets as... 

This program calculates the diameter of a packed column to satisfy a given pressure drop criterium,and estimates the volumetric mass-transfer coefficients. Data presented are from Example 4.4. 

Since the line cool-down model enabled us to predict cool-down times successfully for our test system, we concluded that heat transfer rates across the nitrogen film did not limit line cooling. However, we did obtain heat transfer coefficient data at several locations in the piping system. We estimated the coefficients from line wall and flowing fluid temperature data. Data from horizontal... 

FIGURE A5.1 Behavior of the mass transfer coefficient. [Data from Wakao, N., Recent Advances in the Engineering Analysis of Chemically Reacting Systems (Ed. L.K. Doraiswamy),Wiley Eastern, New Delhi, 1984.]... 

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