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Axial mixing in a 15 cm diameter reciprocating plate bubble column
Author(s) -
Baird Malcolm H. I.,
Rao Nadella V. Rama
Publication year - 1998
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450760305
Subject(s) - reciprocating motion , bubble , mechanics , perforation , amplitude , materials science , dispersion (optics) , countercurrent exchange , plate column , analytical chemistry (journal) , chemistry , physics , optics , composite material , thermodynamics , chromatography , punching , gas compressor
Axial dispersion coefficients ( E ) in the liquid phase have been measured by unsteady tracer response methods in a 15 cm internal diameter reciprocating plate bubble column, using air and water in countercurrent and cocurrent flow. The operating variables studied were amplitude (0.6–1.27 cm) and frequency (0–5 Hz) of reciprocation, and the superficial velocities of the liquid and gas phases and the spacing between plates. Three types of plate were studied; conventional Karr‐type plates with perforation diameters 1.43 cm, plates with smaller (0.635 cm) perforations, and single‐perforation (doughnut) plates with internal diameter 7 cm. Measured values of E ranged from about 1 cm 2 /s to a maximum of 116 cm 2 /s. In general, the plates with 0.635 cm perforations gave the smallest values of E while the largest values of E were obtained with the doughnut plates, due to vortex ring shedding. The single liquid phase data for the three types of plate were approximately consistent with the correlation of Stevens and Baird (1990). The gas‐liquid flow results were interpreted in terms of several different hydrodynamic effects.