Abstract:A new agitation system, called Turboxal, used for the oxygenation and the mixing of wastewater biological treatment tanks has been studied. The interactions between the shell and the three impellers which compose the Turboxal have been analyzed by single‐phase flow patterns. The pumping capacity and the power consumption have also been measured. In addition, the gas dispersion regimes have been analyzed in the tank and in the shell. Finally, the effect of the interaction and the effect of the position of the d… Show more
“…9 shows the flow fields inside the shell. The numerical results are compared with the experimental ones obtained by Laser Doppler Velocimetry [18]. Qualitatively, the same flow field is found.…”
Section: Simulation Of the Turboxal Tm By Cfd In Singlephase Flowsupporting
confidence: 58%
“…To make a more precise analysis, let us compare dimensionless axial and radial velocity profiles obtained experimentally [18] and numerically. A good agreement is found in Figs.…”
Section: Simulation Of the Turboxal Tm By Cfd In Singlephase Flowmentioning
A new device has been developed in order to achieve urban or industrial wastewater biological treatment. It has been designed specially for lagoon applications to oxygenate and mix with the same apparatus. The goal is both to achieve a high gas flooding rate and to reach a maximal depth with the bubble plume. Mass transfer measurements have allowed us to choose the most appropriate geometry. Considering the application of the device and the possible use of low-pressure O 2 produced on-site, the agitation system is located close to the liquid surface and is composed of a gas-inducing turbine. The role of propellers in addition to the gas-inducing turbine, as well as the use of baffles and a shell, have been experimentally studied. Numerical simulations (CFD) of the whole apparatus in single-phase flow have been used to study the influence of the stator part of the geometry.
“…9 shows the flow fields inside the shell. The numerical results are compared with the experimental ones obtained by Laser Doppler Velocimetry [18]. Qualitatively, the same flow field is found.…”
Section: Simulation Of the Turboxal Tm By Cfd In Singlephase Flowsupporting
confidence: 58%
“…To make a more precise analysis, let us compare dimensionless axial and radial velocity profiles obtained experimentally [18] and numerically. A good agreement is found in Figs.…”
Section: Simulation Of the Turboxal Tm By Cfd In Singlephase Flowmentioning
A new device has been developed in order to achieve urban or industrial wastewater biological treatment. It has been designed specially for lagoon applications to oxygenate and mix with the same apparatus. The goal is both to achieve a high gas flooding rate and to reach a maximal depth with the bubble plume. Mass transfer measurements have allowed us to choose the most appropriate geometry. Considering the application of the device and the possible use of low-pressure O 2 produced on-site, the agitation system is located close to the liquid surface and is composed of a gas-inducing turbine. The role of propellers in addition to the gas-inducing turbine, as well as the use of baffles and a shell, have been experimentally studied. Numerical simulations (CFD) of the whole apparatus in single-phase flow have been used to study the influence of the stator part of the geometry.
“…This impeller is the part that controls and generates the gas-liquid dispersion of the Turboxal system, which has been developed for wastewater treatment. [9][10][11] The induced gas flows through a jacket; therefore, the Turboxal is a type 22 gas-inducing impeller.…”
Section: In 1957mentioning
confidence: 99%
“…This turbine has the particularity of having an annular space opening in its upper disk. This impeller is the part that controls and generates the gas−liquid dispersion of the Turboxal system, which has been developed for wastewater treatment. − The induced gas flows through a jacket; therefore, the Turboxal is a type 22 gas-inducing impeller. 2 Milton Roy Mixing gas-inducing turbine.…”
To increase the gas-inducing capacity of a shrouded turbine and avoid using an additional impeller in the
stirred tank, geometrical modifications of the lower disk of this turbine have been considered. The performance
of several new, partially shrouded gas-inducing turbines has been investigated by computational fluid dynamics
for single-phase flow with the Fluent software. The new turbine designs are shown to have pressure coefficients
close to the totally-shrouded-turbine coefficient, corresponding to low critical agitation velocities for gas
inducement but with significantly higher pumping capacities and increased gas-inducing capacities.
Gas-liquid contacting is an important unit operation in chemical and biochemical processes, but the gas utilization efficiency is low in conventional gas-liquid contactors especially for sparingly soluble gases. The gas self-inducing impeller is able to recycle gas in the headspace of a reactor to the liquid without utilization of additional equipment such as a gas compressor, and thus, the gas utilization efficiency is significantly enhanced. Gas induction is caused by the low pressure or deep vortex at a sufficiently high impeller speed, and the speed at which gas induction starts is termed the critical speed. The critical impeller speed, gas-induction flow rate, power consumption, and gas-liquid mass transfer are determined by the impeller design and operation conditions. When the reactor is operated in a dead-end mode, all the introduced gas can be completely used, and this feature is especially favorable to flammable and/or toxic gases. In this article, the principles, designs, characteristics of self-inducing reactors, and applications to biotechnology are described.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
