Experimental study on the performance of an air-lift pump for artificial upwelling

Air-lift pumps for artificial upwelling of ocean water are finding increasing use as marine primary productivity could be enhanced by pumping nutrient-rich deep water to the surface to feed phytoplankton. This paper presents experiments and theoretical analysis to obtain the performance of an air-lift pump for artificial upwelling. Experiments are performed at one submerged depth, with four different air injection nozzle designs and various injected air volume flow rates. A theoretical model is proposed taking into account the flow characteristics of air-lift artificial upwelling. The performance of the model has been confirmed by the experimental findings. The present results show that the pump capacity and efficiency are functions of the geometrical parameters of the upwelling pipe, air volume flow rate, air injection method and vertical distribution of water density. It is found that the upwelling efficiency increases with the increase of the pipe diameter due to the reduction of the frictional loss, the kinetic energy and the power demand of the sea surface rise. Moreover, the air injector design has a considerable effect on the upwelling efficiency. Further work will have to determine the optimal design of the geometrical parameters of the upwelling pipe and the air injection nozzle.

[1]  Arne Fredheim,et al.  Controlled artificial upwelling in a fjord to stimulate non-toxic algae , 2010 .

[2]  M. Salcudean,et al.  Numerical modelling of deep sea air-lift , 2008 .

[3]  William B. Zimmerman,et al.  On the design and simulation of an airlift loop bioreactor with microbubble generation by fluidic oscillation , 2009 .

[4]  Sadek Z. Kassab,et al.  Effect of air injection method on the performance of an air lift pump , 1999 .

[5]  R. Clift,et al.  Bubbles, Drops, and Particles , 1978 .

[6]  Brian Kirke,et al.  Enhancing fish stocks with wave-powered artificial upwelling , 2003 .

[7]  Kern E. Kenyon,et al.  Upwelling by a wave pump , 2007 .

[8]  H. Gawrońska,et al.  Restoration Effectiveness of a Degraded Lake Using Multi-Year Artificial Aeration , 2004 .

[9]  P. Moin,et al.  Turbulence statistics in fully developed channel flow at low Reynolds number , 1987, Journal of Fluid Mechanics.

[10]  Fernando González-Laxe,et al.  Overfishing and the Common Fisheries Policy: (un)successful results from TAC regulation? , 2011 .

[11]  Gerald L. Wick,et al.  Utilization of the energy in ocean waves , 1976 .

[12]  Shigenao Maruyama,et al.  Continuous measurement of an artificial upwelling of deep sea water induced by the perpetual salt fountain , 2007 .

[13]  Nai Kuang Liang.  Concept Design Of Artificial Upwelling Induced By Natural Forces , 1991, OCEANS 91 Proceedings.

[14]  Ira Leifer,et al.  Engineered and Natural Marine Seep, Bubble-Driven Buoyancy Flows , 2009 .

[15]  S. Maruyama,et al.  Nutrient transport from an artificial upwelling of deep sea water , 2009 .

[16]  Qiao Jin,et al.  Artificial upwelling in regular and random waves , 1995 .

[17]  A. Di Gerlando,et al.  Torque and losses in the metallic shell of a dual mechanical port PM electrical machine, for dangerous fluid pumps , 2010, The XIX International Conference on Electrical Machines - ICEM 2010.

[18]  Nai-Kuang Liang,et al.  A study of air-lift artificial upwelling , 2005 .

[19]  C. Crowe,et al.  Engineering fluid mechanics , 1975 .

[20]  Keisuke Taira,et al.  Artificial Upwelling of Deep Seawater Using the Perpetual Salt Fountain for Cultivation of Ocean Desert , 2004 .

[21]  Alain Liné,et al.  Prediction of liquid velocity and gas hold-up in rectangular air-lift reactors of different scales , 2001 .

[22]  Victor A. Dorr,et al.  A submerged hypolimnion aerator , 1975 .

[23]  S. Socolofsky,et al.  Particle Image Velocimetry Measurements of the Mean Flow Characteristics in a Bubble Plume , 2007 .

[24]  Henry Stommel,et al.  An oceanographical curiosity: the perpetual salt fountain , 1956 .

[25]  H. Fischer.  Mixing in Inland and Coastal Waters , 1979 .

[26]  Ø. Strand,et al.  Primary production enhancement by artificial upwelling in a western Norwegian fjord , 2007 .

[27]  Shri Sant,et al.  An experimental analysis of two phase flow for air lift pump design , 2004 .