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| Barrut, Bertrand. |
| The aim of this work was to study the three functions of a vacuum airlift, which are water pumping, mass transfer and foam fractionation. The investigations mainly focused on the treatment of fish culture water and on phytoplancton harvesting_ Each function was studied separately, in order to assess the performance of the vacuum airlift with specific operating conditions. By studying the airlift pump, the effects of water and diffuser types, air injection conditions and depression level were shown. In fresh water, bubble coalescence was observed, which reduced gas holdup compared to sea water. Consequently, the water flow of the vacuum airlift appeared higher in fresh water than in sea water (30 to 35 m3.h-1 against 10 to 20 m3.h-l) for the same air flow... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00050/16091/13979.pdf |
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| Barrut, Bertrand; Blancheton, Jean-paul; Callier, Myriam; Champagne, Jean-yves; Grasmick, Alain. |
| The accumulation of particulate organic matter (POM) in recirculating aquaculture systems (RAS) has become an important issue with the intensification of finfish production. The objective of this study was to assess the foam fractionation efficiency of a vacuum airlift in different conditions (POM concentrations, airflow rates, bubble sizes, water renewal rates and feed addition). In sea water, the vacuum airlift allowed removing 20% of the initial POM concentration per hour (foam fractionation efficiency), corresponding to a 20.7-fold concentration factor between the tank and the foam. In rearing conditions, efficiency increased with decreasing water renewal rate or increasing POM concentration. An increase in airflow rate from 10 to 80 L min−1 in the... |
| Tipo: Text |
Palavras-chave: POM; Vacuum airlift; Foam fractionation efficiency; RAS; Aquaculture. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00138/24910/23576.pdf |
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| Barrut, Bertrand; Blancheton, Jean-paul; Champagne, Jean-yves; Grasmick, Alain. |
| In aquaculture, oxygen transfer and carbon dioxide stripping are the first limiting factors to fish rearing intensification. In this study we measured the O-2 and CO2 mass transfer coefficient (K(L)a) for a vacuum airlift in fresh (<1% salinity) and sea water (35 parts per thousand salinity) recirculating aquaculture systems (RAS). The airlift was composed of two concentric tubes: an inner riser tube and an external downcomer tube and can be adjusted at three different heights: 2,4 or 6 m. Several types of air injectors were tested, delivering different sizes of bubble swarms depending on their porosity and functioning conditions (low or high injection pressure), with air flows varying from 0 to 80 L min(-1). Experiments were also carried out at... |
| Tipo: Text |
Palavras-chave: Mass transfer; Airlift; Vacuum; Aquaculture; RAS; Aeration; Degasification; Salinity. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00072/18324/16001.pdf |
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| Barrut, Bertrand; Blancheton, Jean-paul; Champagne, Jean-yves; Grasmick, Alain. |
| A study was undertaken to measure the water flow (Qw) delivered by a vacuum airlift designed for recirculating aquaculture systems (RAS) in fresh (<1‰ of salinity) and sea water (35‰ of salinity). The vacuum airlift consists of two concentric tubes connected at their top to a depression chamber. The water rises in the inner tube as a result of air being injected in its lower section and flows back through the external downcomer tube. The vacuum airlift was adjusted at three different lengths: 2, 4 or 6 m and water discharge could be lifted from 0 to 30 cm. Air flow rate (Qg) varied from 0 to 80 L min−1. Different types of air injectors were tested, delivering different bubble sizes (0.1–5 mm) depending on porosity and functioning at low or high... |
| Tipo: Text |
Palavras-chave: Water circulation; Airlift; Vacuum; Aquaculture; RAS; Salinity. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00073/18457/16005.pdf |
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