Determination of the volumetric mass transfer coefficient (kLa) using the dynamic ?gas out-gas in? method: Analysis of errors caused by dissolved oxygen probes

1995 ◽  
Vol 46 (4) ◽  
pp. 388-392 ◽  
Author(s):  
L. A. Tribe ◽  
C. L. Briens ◽  
A. Margaritis
Keyword(s):  
Mass Transfer ◽  
Dissolved Oxygen ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Volumetric Mass Transfer Coefficient ◽  
Oxygen Probes ◽  
Method Analysis

scholarly journals Gas–liquid mass transfer characteristics of aviation fuel scrubbing in an aircraft fuel tank

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li Chaoyue ◽  
Feng Shiyu ◽  
Xu Lei ◽  
Peng Xiaotian ◽  
Yan Yan
Keyword(s):  
Mass Transfer ◽  
Dissolved Oxygen ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Oxygen Concentration ◽  
Gas Holdup ◽  
Aviation Fuel ◽  
Volumetric Mass Transfer Coefficient ◽  
Dissolved Oxygen Concentration ◽  
Liquid Mass Transfer

AbstractDissolved oxygen evolving from aviation fuel leads to an increase in the oxygen concentration in an inert aircraft fuel tank ullage that may increase the flammability of the tank. Aviation fuel scrubbing with nitrogen-enriched air (NEA) can largely reduce the amount of dissolved oxygen and counteract the adverse effect of oxygen evolution. The gas–liquid mass transfer characteristics of aviation fuel scrubbing are investigated using the computational fluid dynamics method, which is verified experimentally. The effects of the NEA bubble diameter, NEA superficial velocity and fuel load on oxygen transfer between NEA and aviation fuel are discussed. Findings from this work indicate that the descent rate of the average dissolved oxygen concentration, gas holdup distribution and volumetric mass transfer coefficient increase with increasing NEA superficial velocity but decrease with increasing bubble diameter and fuel load. When the bubble diameter varies from 1 to 4 mm, the maximum change of descent rate of dissolved oxygen concentration is 18.46%, the gas holdup is 8.73%, the oxygen volumetric mass transfer coefficient is 81.45%. When the NEA superficial velocities varies from 0.04 to 0.10 m/s, the maximum change of descent rate of dissolved oxygen concentration is 146.77%, the gas holdup is 77.14%, the oxygen volumetric mass transfer coefficient is 175.38%. When the fuel load varies from 35 to 80%, the maximum change of descent rate of dissolved oxygen concentration is 21.15%, the gas holdup is 49.54%, the oxygen volumetric mass transfer coefficient is 44.57%. These results provide a better understanding of the gas and liquid mass transfer characteristics of aviation fuel scrubbing in aircraft fuel tanks and can promote the optimal design of fuel scrubbing inerting systems.

scholarly journals Determination of the ozone volumetric mass transfer coefficient in bubble column with two-fluid nozzle gas distributor

2015 ◽  
Vol 69 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Milica Djekovic-Sevic ◽  
Nevenka Boskovic-Vragolovic ◽  
Ljiljana Takic ◽  
Radmila Garic-Grulovic ◽  
Srdjan Pejanovic
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Bubble Column ◽  
Operating Conditions ◽  
Volumetric Mass Transfer Coefficient ◽  
Gas Distributor ◽  
Liquid Mass Transfer ◽  
Two Fluid

Experimental investigation of gas-liquid mass transfer of ozone in water, in bubble column with two-fluid nozzle gas distributor (BKDM), under different operating conditions, are presented in this work. The main objective was to determine the ozone volumetric mass transfer coefficient, kL a, in calm uniform section of the column, under different values of gas and liquid flow rates. Obtained values of these coefficients were compared with the values in countercurrent bubble column. The critical liquid flowrate, when gas hold up reaches its maximum, was experimentally determined. It was shown that the maximum value of the ozone volumetric mass transfer coefficient is obtained just when liquid flowrate is at its critical value.

scholarly journals Sizes of the actively aerated zone and methods of the jet aerator calculation

2021 ◽  
Vol 264 ◽  
pp. 01020
Author(s):  
Malokhat Abdukodyrova ◽  
Maria Radkevich ◽  
Kamila Shipilova ◽  
Abdusamin Gapirov
Keyword(s):  
Mass Transfer ◽  
Wastewater Treatment ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Shallow Depth ◽  
Biological Wastewater Treatment ◽  
Relative Depth ◽  
Volumetric Mass Transfer Coefficient ◽  
Reservoir Volume

The possibilities of using jet aeration for biological wastewater treatment in small facilities were considered in the article. In shallow depth reservoirs, studies were carried out to change the sizes of the actively aerated zone with a decrease in the height of the liquid layer in the reservoir. The research was conducted for jet aerators with nozzles of the "keyway" type holes. It was established that a decrease in the relative depth of the reservoir makes it possible to increase the share of the beneficial use of the reservoir volume. This suggests that jet aeration will be most effective for reservoirs of relatively shallow depth. Based on the research results, a method for calculating a jet aerator was proposed, which makes it possible to evaluate the necessary parameters of the aerator based on the determination of the volumetric mass transfer coefficient.

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