Organic heat transfer coefficient

Heat-transfer coefficients in steam-tube dryers range from 30 to 85 J/(m s K). Coefficients will increasewith increasing steam temperature because of increased heat transfer by radiation. In units carrying saturated steam at 420 to 450 K, the heat flux UAT will range from 6300 J/(m s) for difficult-to-diy and organic solids and to 1890 to 3790 J/(m s) for finely divided inorganic materials. The effect of steam pressure on heat-transfer rates up to 8.6 X 10 Pa is illustrated in Fig. 12-71. 

Tube side Determine heat transfer coefficient from Figure 10-46 (using tube-side curve) at Reynold s number calculated for pressure drop evaluation. If the hj calculated exceeds 300 for organics (Figure 10-103), use a value of 300 and correct to outside coefficient, hj. ... 

An organic liquid is boiling at 340 K on the inside of a metal surface of thermal conductivity 42 W/m K and thickness 3 mm. The outside of the surface is heated by condensing steam. Assuming that the heat transfer coefficient from steam to the outer metal surface is constant at 11 kW/m2 K, irrespective of the steam temperature, find the value of the steam temperature to give a maximum rate of evaporation. 

The design of devices to promote cocurrent drop flows for heating or cooling a two-phase system, or for direct-contact heat transfer between two liquids, is difficult. The study by Wilke et al. (W7) is typical of the approach frequently used to analyze these processes. Wilke et al. described the direct-contact heat transfer between Aroclor (a heavy organic liquid) and seawater in a 3-in. pipe. No attempt was made to describe the flow pattern that existed in the system. The interfacial heat-transfer coefficient was defined by... 

Models and Correlations. A multitude of different models and correlations have been proposed for prediction of the heat transfer coefficient at vertical surfaces in fast fluidized beds. To organize the various models in some context, it is helpful to consider the total heat transfer coefficient as comprised of convective contributions from the lean-gas... 

Typical Agitator-Side Heat Transfer Coefficients of Organic Fluids... 

Figure 4 Typical agitator-side heat transfer coefficients of organic fluids.

Condensation of mixed vapors of immiscible liquids is not well understood. The conservative approach is to assume that two condensate films are present and all the heat must be transferred through both films in series. Another approach is to use a mass fraction average thermal conductivity and calculate the heat-transfer coefficient using the viscosity of the film-forming component (the organic component for water-organic mixtures). 

Mndhoo, A. and Mohee, R. 2007. Overall heat transfer coefficients in organic snbstrates composting. Journal of Environmental Informatics, 9 87-99. 

A large number of binary mixtures of organic liquids and of water with organic liquids were first investigated by Bonilla and Perry [4.100]. In Fig. 4.56 the heat transfer coefficients found from their measurements with an ethanol-water mixture are presented along with the results from Preufier [4.101]. Heat flux and pressure are indicated in the diagram. As we can see, the heat transfer coefficients a of the mixture are noticeably smaller than the values aid, which would be obtained, if we had interpolated linearly between the heat transfer coefficients of the pure... 

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