The influence of a spiral element on the longitudinal dispersion of liquid in thin layer evaporator

✍ Scribed by Adam Skoczylas; Andrzej Urbański

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 392 KB
• Volume: 62
• Category: Article
• ISSN: 0923-0467
• DOI: 10.1016/0923-0467(95)03057-3

✦ Synopsis

The application of a spiral element in a static thin layer evaporator (STLE) radically changes both the hydrodynamics and consequently the rate of heat transfer. The principal objective of our work was to establish a relationship between the longitudinal mixing of liquid in the thin layer evaporator (TLE) and conditions of flow down the evaporator surface.

A total of 221 measurements have been performed using the STLE and the TLE equipped with spiral elements of two different pitches. The quantitative measure of the longitudinal mixing is the coefficient (D) which in our work changed from (280 \times 10^{-5} \mathrm{~m}^{2} \mathrm{~s}^{-1}), for the TLE equipped with immovable spiral element 1 , to (3159 \times 10^{-5} \mathrm{~m}^{2} \mathrm{~s}^{-1}) for the STLE. The numerical values of the longitudinal dispersion coefficients (D), for all measurements, represent a logical integrity. The smaller the spiral pitch, the smaller is the coefficient (D), and more profitable conditions occur for heat and mass transfer.