scholarly journals Hydrophobic VOC absorption in two-phase partitioning bioreactors; influence of silicone oil volume fraction on absorber diameter

2012 ◽  
Vol 71 ◽  
pp. 146-152 ◽  
Author(s):  
Eric Dumont ◽  
Guillaume Darracq ◽  
Annabelle Couvert ◽  
Catherine Couriol ◽  
Abdeltif Amrane ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Silicone Oil ◽  
Two Phase ◽  
Phase Partitioning ◽  
Hydrophobic Voc

Aerobic phenanthrene biodegradation in a two-phase partitioning bioreactor

2005 ◽  
Vol 52 (8) ◽  
pp. 265-271 ◽  
Author(s):  
R. Muñoz ◽  
C. Rolvering ◽  
B. Guieysse ◽  
B. Mattiasson
Keyword(s):  
Silicone Oil ◽  
Liquid Volume ◽  
Agitation Rate ◽  
Two Phase ◽  
Phase Partitioning ◽  
Partitioning Bioreactor ◽  
Photosynthetic Oxygenation ◽  
Mechanical Aeration ◽  
Phenanthrene Biodegradation ◽  
Two Phase Partitioning Bioreactor

The aerobic degradation of phenanthrene by a Pseudomonas migulae strain under classical mechanical aeration and under photosynthetic oxygenation (using a Chlorella sorokiniana strain) in a two-phase partitioning bioreactor (TPPB) constructed with silicone oil as organic phase was investigated. When traditional mechanical aeration was used, an increase in the aeration and/or in the agitation rate enhanced phenanthrene biodegradation. Thus, phenanthrene removal rates (based on the total liquid volume of cultivation) ranged from 22±1 to 36±2mg/lh at 100rpm and 1vvm and 400rpm and 3vvm, respectively. On the other hand, during phenanthrene biodegradation using the algal-bacterial microcosm a maximum rate of 8.1±1.2mg/lh at 200rpm and 8000 lux of illuminance was achieved.

scholarly journals Evaluation of Parallel-Series Configurations of Two-Phase Partitioning Biotrickling Filtration and Biotrickling Filtration for Treating Styrene Gas-Phase Emissions

2020 ◽  
Vol 12 (17) ◽  
pp. 6740 ◽  
Author(s):  
Pau San-Valero ◽  
Javier Álvarez-Hornos ◽  
Pablo Ferrero ◽  
Josep M. Penya-Roja ◽  
Paula Marzal ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Silicone Oil ◽  
Sharp Decrease ◽  
Complete Removal ◽  
Industrial Applications ◽  
Biotrickling Filter ◽  
Gaseous Emissions ◽  
Two Phase ◽  
Phase Partitioning ◽  
In Series

The removal of styrene from industrial representative gaseous emissions was studied using two reactors connected in series: a two-phase partitioning biotrickling filter (TPPB-BTF) and a conventional biotrickling filter (BTF). The system was operated under industrial conditions, which included steady and transient conditions and intermittent spraying. Silicone oil was used in the TPPB-BTF with a quantity as low as 25 mL L−1, promoting a faster start-up compared to the BTF. By working at a styrene loading of 30 g m−3 h−1, nearly complete removal efficiency (RE) was obtained. In addition, the removal was not adversely impacted by using non-steady emission patterns such as overnight shutdowns (97% RE) and oscillating concentrations (95% RE), demonstrating its viability for industrial applications. After 2 months from inoculation, two additional configurations (reverse series BTF + TPPB-BTF and parallel) were tested, showing the series configuration as the best approach to consistently achieve RE > 95%. After 51 days of operation, high throughput sequencing revealed a sharp decrease in the bacterial diversity. In both reactors, the microorganisms belonging to the Comamonadaceae family were predominant and other styrene degraders such as Pseudomonadaceae proliferated preferably in the first reactor.

scholarly journals Experimental Study of the Static and Dynamic Characteristics of a Long (L/D = 0.75) Labyrinth Annular Seal Operating Under Two-Phase (Liquid/Gas) Conditions

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Hari Shrestha ◽  
Dara W. Childs ◽  
Dung L. Tran ◽  
Min Zhang
Keyword(s):  
Volume Fraction ◽  
Silicone Oil ◽  
Dynamic Stiffness ◽  
Labyrinth Seal ◽  
Radial Clearance ◽  
Labyrinth Seals ◽  
Two Phase ◽  
Annular Seal ◽  
The Stability ◽  
Gas Volume

AbstractA two-phase annular-seal stand at the Turbomachinery Laboratory of Texas A&M University is utilized to experimentally investigate a labyrinth seal operating under two-phase flow conditions (a mixture of silicone oil and air). A long labyrinth seal (length-to-diameter ratio L/D = 0.75, diameter D = 114.729 mm, and radial clearance Cr = 0.213 mm) is tested at a supply pressure of 62 bars-g with inlet gas volume fraction GVFi ranging from 90 to 100%. Tests were conducted at three pressure ratios PR (0.3, 0.4, 0.5), three rotating speeds (5, 10, 15 krpm), six GVFi (90%, 92%, 94%, 96%, 98%, and 100%), and three inlet-preswirl inserts, namely, zero, medium, and high. Specifically, the ratio between the fluid's circumferential velocity and the shaft surface's velocity are in ranges of 0.0–0.2, 0.5–1.6, and 0.5–2.7 for the zero, medium, and high preswirls respectively. The direct dynamic stiffness KΩ is negative. As GVFi decreases (more liquid), KΩ becomes more negative for the zero preswirl. The effect of changing GVFi on KΩ for the medium and high preswirls is not as clear as for the zero preswirl. For the zero preswirl, as GVFi decreases, the cross-coupled dynamic stiffness kΩ and direct damping C damping increase. However, the effective damping Ceff values converge to almost the same positive value for higher frequencies. Hence, there is no significant effect of change in GVFi for the zero preswirl. For the high preswirl, as GVFi decreases, kΩ decreases and C increases. As GVFi decreases, Ceff becomes less negative and eventually becomes positive for frequencies higher than Ωc. This result indicates that at certain frequencies, the presence of liquid can make the labyrinth seals with high preswirl more stable. For the seal tested, a compressor running at 15 krpm and PR (ratio of seal exit pressure and seal inlet pressure) = 0.5 with the first critical speed of 7500 rpm (125 Hz) would experience an increase in stability with presence of liquid in the flow stream for the medium and high preswirls. However, for the range of GVFi considered here, if swirl brakes are used in a compressor application to reduce the preswirl, there would be no impact of liquid presence on the stability of the compressor. Concerning static measurements, leakage rate m˙ increases with decreases in GVFi but remains unchanged with increasing preswirl.

Modeling Study of Crude Oil Enhanced Removal in a Two-Liquid Phase Partitioning Bioreactor

2015 ◽  
Vol 13 (3) ◽  
pp. 381-388
Author(s):  
Zainab Z. Ismail ◽  
Ibtihaj A. Abdulrazzak
Keyword(s):  
Crude Oil ◽  
Silicone Oil ◽  
Complete Removal ◽  
Two Phase ◽  
Phase Partitioning ◽  
Proposed Model ◽  
Transfer Equations ◽  
Oil Concentration ◽  
Dynamic Growth ◽  
Suspended Cells

Abstract A combined process of solvent extraction and two-phase biodegradation was carried out to remove crude oil from water by mixed cultures, where silicone oil was selected as the organic solvent due to its biocompatibility and non-biodegradability. The crude oil removal and cell growth was experimentally studied. A simple model that combined steady mass transfer equations and dynamic growth kinetics of suspended cells was suggested to follow the entire process. Under the conditions studied, complete removal of crude oil from water was achieved at initial crude oil concentration of 5,000 mg/L. Results revealed that the proposed model satisfactorily described the process as long as crude oil level in the cell medium did not exceed the toxicity limit of suspended cells.

scholarly journals Experimental Study of the Static and Dynamic Characteristics of a Long (L/D=0.75) Labyrinth Annular Seal Operating Under Two-Phase (Liquid/Gas) Conditions

2019 ◽  
Author(s):  
Hari Shrestha ◽  
Dara W. Childs ◽  
Dung L. Tran ◽  
Min Zhang
Keyword(s):  
Volume Fraction ◽  
Silicone Oil ◽  
Dynamic Stiffness ◽  
Labyrinth Seal ◽  
Radial Clearance ◽  
Labyrinth Seals ◽  
Two Phase ◽  
Annular Seal ◽  
The Stability ◽  
Gas Volume

Abstract A 2-phase annular-seal stand (2PASS) at the Turbomachinery Laboratory of Texas A&M University is utilized to experimentally investigate a labyrinth seal operating under 2-phase flow conditions (a mixture of silicone oil and air). A long labyrinth seal (length-to-diameter ratio L/D = 0.75, diameter D = 114.729 mm, and radial clearance Cr = 0.213 mm) is tested at a supply pressure of 62 bars-g with inlet gas volume fraction GVFi ranging from 90–100%. Tests were conducted at three pressure ratios PR (0.3, 0.4, 0.5), three rotating speeds (5, 10, 15 krpm), six GVFi (90%, 92%, 94%, 96%, 98%, 100%), and three inlet-preswirl inserts, namely, zero, medium, and high. Specifically, the ratio between the fluid’s circumferential velocity and the shaft surface’s velocity, are in ranges of 0.0–0.2, 0.5–1.6, and 0.5–2.7 for the zero, medium, and high preswirls, respectively. The direct dynamic stiffness KΩ is negative. As GVFi decreases (more liquid), KΩ becomes more negative for the zero preswirl. The effect of changing GVFi on KΩ for the medium and high preswirls is not as clear as for the zero preswirl. For the zero preswirl, as GVFi decreases, the cross-coupled dynamic stiffness kΩ and direct damping C damping increases. However, the effective damping Ceff values converge to almost the same positive value for higher frequencies. Hence, there is no significant effect of change in GVFi for the zero preswirl. For the high preswirl, as GVFi decreases, kΩ decreases and C increases. As GVFi decreases, Ceff becomes less negative and eventually becomes positive for frequencies higher than Ωc. This result indicates that at certain frequencies, the presence of liquid can make the labyrinth seals with high preswirl more stable. For the seal tested, a compressor running at 15 krpm and PR (ratio of seal exit pressure and seal inlet pressure) = 0.5 with the first critical speed of 7500 rpm (125 Hz) would experience an increase in stability with presence of liquid in the flow stream for the medium and high preswirls. However, for the range of GVFi considered here, if swirl brakes are used in a compressor application to reduce the preswirl, there would be no impact of liquid presence on the stability of the compressor. Concerning static measurements, leakage rate ṁ increases with decreases in GVFi but remains unchanged with increasing preswirl.

Activated Sludge Acclimation for Hydrophobic VOC Removal in a Two-Phase Partitioning Reactor

2012 ◽  
Vol 223 (6) ◽  
pp. 3117-3124 ◽  
Author(s):  
Guillaume Darracq ◽  
Annabelle Couvert ◽  
Catherine Couriol ◽  
Eric Dumont ◽  
Abdeltif Amrane ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Two Phase ◽  
Voc Removal ◽  
Phase Partitioning ◽  
Hydrophobic Voc

A Study on the Leakage and Rotordynamic Coefficients of a Long-Smooth Seal With Laminar-Two-Phase, Mainly-Oil Mixtures

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Min Zhang ◽  
Dara W. Childs ◽  
Dung L. Tran ◽  
Hari Shrestha
Keyword(s):  
Laminar Flow ◽  
Volume Fraction ◽  
Silicone Oil ◽  
Dynamic Stiffness ◽  
Radial Clearance ◽  
Inlet Temperature ◽  
Virtual Mass ◽  
Flow Conditions ◽  
Two Phase ◽  
Rotordynamic Coefficients

Abstract This paper conducts a comprehensive study on the effects of the presence of air in the oil on the leakage and rotordynamic coefficients of a long-smooth seal (inner diameter D = 89.306 mm, radial clearance Cr = 0.140 mm, and length-diameter ratio L/D = 0.65) under laminar-two-phase flow conditions. The mixture consists of air and silicone oil with inlet gas volume fraction (GVF) up to 10%. Tests are performed at inlet temperature Ti = 39.4 °C, exit pressure Pe = 6.9 bars, pressure drop PD = 31, and 37.9 bars, and rotor speed ω = 5, 7.5, and 10 krpm. The test seal is always concentric with the rotor, and no intentional fluid prerotation is provided at the seal inlet. The complex dynamic stiffness coefficients Hij of the test seal are measured and fitted by the frequency-independent direct stiffness K, cross-coupled stiffness k, direct damping C, cross-coupled damping c, direct virtual-mass M, and cross-coupled virtual-mass mq coefficients. Under laminar flow conditions, increasing inlet GVF has negligible effects on K, k, C, and effective damping Ceff, while it decreases c and M. These trends are correctly predicted by San Andrés's bulk-flow model with laminar flow friction formula. As inlet GVF increases, measured leakage flow rate m˙ increases slightly. In general, the predictions of K, k, C, c, Ceff, and m˙ are reasonably close to measurements.

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