Calculating With the Theoretical Approach of The Settling Velocity of Fish Feed Pellets

Abstract

This study, settling velocity of fish feed pellets was investigated using the formula given by Isaacs and Thodos [1]. This formula is accurate for large pellets (larger the 3.5-4 mm diameter). The settling velocity data in the literature was compared to the predictions of this formula and good agreement was found. The formula also has implications on how settling velocity depends on various parameters such as water temperature, salinity, pellet diameter, length, density of pellet etc.  Settling velocity was found to be extremely sensitive to errors in density measurements of pellets according to the Isaacs and Thodos [1] formula. A few percent errors in particle density found to cause large deviations in settling velocity. Settling velocity is independent of viscosity according to Isaacs and Thodos formula. The settling velocity was also found to be largely independent of temperature for large pellets. The settling velocity is proportional to square root of diameter according to Isaacs and Thodos formula.  This dependence on square root of diameter was demonstrated using the data from Sutherland et al. [2]  paper. Salinity was also found to be important parameter. Salinity affects settling velocity by increasing density of water and tends to decrease settling velocity.

Keywords

• Balık yemi, batma hızı, sürtünme kuvveti, sürtünme katsayısı

References

1. Isaacs, J. L. and Thodos, G., The Free settling of cylindrical particles in the turbulent regime. Canadian Journal of Chemical Engineering, 45 (1967) 150-155.
2. Sutherland, T. F. Amos, C. L. Droppo, I. G. and Petersen, S. A., The settling behaviour and benthic transport of fish feed pellets under steady flows. Estuaries and Coasts, 29 (2006) 810-819.
3. Cromey, C.J. Nickell, T. D. And Black, K. D., DEPOMOD-modeling the deposition and biological effects of waste solids from marine cage farms. Aquaculture, 214 (2002) 211-239.
4. Doglioli, A. M. Magaldi, M. G. Vezzulli, V. and Tucci, S., Development of numerical model to study the dispersion of wastes coming from a marine fish farm in the Ligurian Sea (Western Mediterranean). Aquaculture, 231 (2004) 215-235.
5. Piedecausa, M. A. Aguado–Gimenez, F. Valverde, J. C. Llorente, M. D. H. and Garcia-Garcia, B., Influence of fish food and faecal pellets on short-term oxygen uptake, ammonium flux and acid volatile sulphide accumulation in sediments impacted by fish farming and non-impacted sediments. Aquaculture Research, 20, 43 (2012) 66–74.
6. Pérez, Ó. Almansa, E. Riera, R. Rodriguez, M. Ramos, E. Costa, J. and Monterroso, Ó., Food and faeces settling velocities of meagre (Argyrosomus regius) and its application for modelling waste dispersion from sea cage aquaculture. Aquaculture, 420–421 (2014) 171–179
7. Findlay, R. H. and Wattling, L., Towards a process level model to predict the effect of salmon net-pen aquaculture on the benthos. In: Modeling Benthic Impacts of Organic Enrichment from Marine Agriculture, Canadian Technical Report of Fish. and Aquatic Society 1949 (ed. By B. T. Hargrave), (1994) pp. 47-77. Canadian Technical Report of Fisheries and Aquatic Society 1949, Dartmouth, Novia Scotia, Canada.
8. Elberizon, I. R. and Kelly, L. A., Empirical measurements of parameters critical to modeling benthic impacts of freshwater salmonid cage aquaculture. Aquaculture Research, 29 (1998) 183-195.

9. Chen, Yrong-Song, Beveridge, M. C. M. and Telfer, T. C., Physical Characteristics of Commercial Pelleted Atlantic Salmon Feeds and Consideration of Implications for Modeling of Waste Dispersion Through Sedimentation. Aquaculture International, 7 (1999) 89-100.
10. Vassalo, P. Doglioli, A.M. Rinaldi, F. and Beiso, H., Determination of physical behaviour of feed pellets in Mediterranean water. Aquaculture Research, 37 (2006) 119-126.
11. Piedecausa, M. A. Aguado–Gimenez, F. and Garcia-Garcia, B., Settling velocity and total ammonia nitrogen leaching from commercial feed and faecal pellets of gilthead sea bream (Sparus aurata L. 1758) and sea bass (Dicentrarchus labrax L. 1758). Aquaculture Research, 40 (2009) 1703-1714.
12. Chhabra, R.P. Agarwal, L. And Sinha, N. K., Drag on non-spherical particles: an evaluation of available methods. Powder Technology, 101 (1999) 288-295.
13. Gabitto, J. and Tsouris, C., Drag coefficient and settling velocity for particles of cylindrical shape. Powder Technology, 183 (2008) 314-322.
14. Loth, E., Drag of non-spherical solid particles of regular and irregular shape. Powder Technology, 182 (2008) 342-353.
15. Clift, R. Grace, J. R. and Weber, M. E., Bubbles, drops and particles. Academic Press, (1978) New York. (ISBN 0-12-176950-X)
16. Siedler, G. and Peters, H., Physical properties (General) of seawater. In:LANDOLT-BÖRNSTEIN. Numerical data and functional relationship in science and technology V/3a, Springer, Berlin, (1986) 233-264.