A heat transfer model for the steady-state simulation of climbing-falling-film plate evaporators

As an economical alternative for the concentration of heat sensitive materials, the climbing-falling-film plate evaporator was used for the first time in 1958. Nevertheless, there seems to be little information in the literature about such equipment. In this paper, an algorithm for the steady-state simulation of this evaporator is presented, which takes into account a general unit with n sets of four plates, whose feed can be at a temperature equal, inferior or superior to its saturation value for the operating pressure. The heating fluid, steam, can be fed either in a saturated or superheated state, with the possibility of condensate subcooling within the equipment channels. Initially, the algorithm was tested for simulating a sample unit at different operating conditions, and the physical consistency of the obtained results was analysed. The efficiency of the developed model was then demonstrated by the successful simulation of six industrial units used for concentrating milk in a Brazilian milk powder plant. [ABSTRACT FROM AUTHOR]