J. Fischer et al., ON THE LOCAL GAS HOLDUP AND FLOW PATTERN IN STANDARD-TYPE BUBBLE-COLUMNS, Chemical engineering and processing, 33(1), 1994, pp. 7-21
Local gas holdups and bubble size distributions have been measured sim
ultaneously in a standard-type bubble column equipped with a perforate
d plate as a gas disperser. High values in the time series of the loca
l gas holdup which appear on a periodic basis could be detected and an
alyzed. The phenomenon of the bubble hose, defined as a zone of high b
ubble number density moving helically in a bubble column, has been rec
ognized visually using photographs and by means of the recorded data.
A formation mechanism for the bubble hose dependent on the gas dispers
er geometry capable of explaining the observed asymmetric liquid and g
as flow pattern is suggested. The existence of a relationship between
the bubble hose, the average bubble diameter and the superficial gas v
elocity has been demonstrated.