Design of Industrial Falling Film Evaporators DOI: http://dx.doi.org/10.5772/intechopen.84230

The heat transfer correlations available in the literature are based on different parameters and they have some limitations. Table 2 showed most famous and widely accepted heat transfer coefficient correlations and their limitations.

The most commonly used correlation is proposed by Han and Fletcher for horizontal tube falling film evaporators. They developed this correlation for pure water at saturation temperature ranges from 322 to 393 K. It can be noticed that there are two major gaps in available literature; firstly, no data is available for evaporation heat transfer for below 322 K and secondly, there is lack of data for salt solution as boiling point elevation changes with salt concentration. These two factors are important for processes industries falling film evaporators design as most of processes are performed below 322 K such as in food and desalination industries [30–42]. This was the main motivation of this study, to provide detailed parameters for falling film evaporators design for process industries. We developed falling film heat transfer coefficient (FFHTC) correlation for saline water evaporation from 280 to 305 K saturation temperatures. We also demonstrated the effect of salt concentration on heat transfer and LMTD. This will help to design efficient falling film evaporators for processes industries.
