| dc.description.abstract | Gas flow through different convergent-divergent nozzles has been studied. The aim of this research
consists on estimating the gas-liquid momentum transfer during the submerged injection. To account
for the momentum transfer, pressure along the nozzles was measured with pressure transducers, these
sensors were plugged to a data acquisition unit so pressure readings were continuously recorded in a
PC. Pressure drops were estimated at the different sections of each tested nozzle. It was found that
change in diameter ratios for the convergent-divergent nozzles have a definitive effect on the
performance of these tuyeres during gas injection to the liquid.
In addition to pressure measurements, CFD modeling of the gas flow within each nozzle and that of the
gas-liquid interaction were conducted. In every case, results showed numerical agreement with
experimental observations. Furthermore high speed video of gas injection confirms numerical results.
In terms of grading the tuyeres tested in this investigation, tuyere 5 is the one that can be mentioned as
the best one in terms of the amount of momentum transferred to the water. With this nozzle, the
maximum momentum was achieved at the lowest gas flow (30 L/min). Tuyeres 7 and 9 were equal in
dimensions, but the angle at the discharge point varied from 13 to 8°. Momentum analysis in these
nozzles reveals that air approaches sonic velocities but at gas flowrates higher than that needed for
tuyere 5.
Regarding to tuyeres 6 & 8, it was not possible to reach sonic flow, only tuyere 6 approached this flow
at excessively high gas flowrate. | |
