Structural Engineering and Mechanics

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Experimental investigation of the effect of baffles on the efficiency improvement of irrigation sedimentation tank structures

  • Received : 2017.04.11
  • Accepted : 2017.07.19
  • Published : 2017.08.25
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Abstract

Sedimentation tanks are essential structures to filter the suspended sediments in the inlet flow which are constructed at the inlet of the basins forked from rivers and irrigation canals. The larger the constructed tank, the better the sedimentation process is conducted. However, the construction and dredging costs increase. In this regard, improving the performance and sedimentation efficiency seem necessary by alternative methods. One of these effective methods is using baffle plates. Most of the studies carried out in this field are on the use of these baffles in the primary and secondary sedimentation tanks. Hence, this study is carrier out with the objective of increasing the retention efficiency in the irrigation sedimentation tanks using baffles. To reach this goal, the experiments were carried out in a flume with length 8 meters, width 0.3 meters, and height 0.5 meters, considering a sedimentation tanks with a length of 3 meters, in three different inlet concentration, three flow rates and three Froude numbers. The baffles were mounted at the bottom of the tank and the effects of the angle, height and position in the tanks were investigated. The results showed that on average, employing the baffles increased the sedimentation efficiency 5 to 6% and the highest value was obtained for angle 60 with respect to the flow direction. According to the results of this study, the most favorable height and position of these baffles were obtained to be in 40% of the depth of the flow and 50% of the length of the sedimentation tank, respectively. Also, by increasing the number of baffles, the sedimentation efficiency decreased. Regarding the sedimentation regions in this case, more than 80% of the settled sediments were observed in the middle of the tank measured from the inlet.

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References

  1. Ahmed, F.H., Kamel, A. and Abdel Jawad, S. (1996), "Experimental determination of the optimal location and contraction of sedimentation tank baffles", Water, Air Soil Pollut., 92, 251-271.
  2. Bretscher, U., Krebs, P. and Hager, W.H. (1992), "Improvement of flow in final settling tanks", J. Environ. Eng., 118(3), 307-321. https://doi.org/10.1061/(ASCE)0733-9372(1992)118:3(307)
  3. Goula, A.M., Kostoglou, M., Karapantsios, T.D. and Zouboulis, A.I. (2007), "A CFD methodology for the design of sedimentation tanks in potable water treatment case study: the influence of a feed flow control baffle", Chem. Eng. J., 140, 110-121.
  4. He, C., Scott, E. and Rochfort, Q. (2015), "Enhancing sedimentation by improving flow conditions using parallel retrofit baffles", J. Environ. Manag., 160, 1-6. https://doi.org/10.1016/j.jenvman.2015.06.013
  5. Huggins, D.L., Piedrahita, R.H. and Rumsey, T. (2005), "Analysis of sediment transport modeling using computational fluid", Aquacultur. Eng., 31, 277-293.
  6. Jamshidnia, H. and Firoozabadi, B. (2010), "Experimental investigation of baffle effect on the flow in a rectangular primary sedimentation tank", Tran. B: Mech. Eng., 17, 241-252.
  7. Khademi, M., Omid, M.H. and Hourfar, A. (2008), "Experimental and numerical investigation of the effect of submerged baffle on the trap efficiency of settling basin", J. Hydraulics., 2, 11-24.
  8. Kolaei, A., Rakheja, S. and Richard, M.J. (2017), "Coupled multimodal fluid-vehicle model for analysis of anti-slosh effectiveness of longitudinal baffles in a partially-filled tank vehicle", J. Fluid Struct., 70, 519-536. https://doi.org/10.1016/j.jfluidstructs.2017.02.012
  9. Lee, S.Y., Cho, J.R., Park, T.H. and Lee, W.Y. (2002), "baffled fuel-storage container: parametric study on transient dynamic characteristics", Struct. Eng. Mech., 13, 653-670. https://doi.org/10.12989/sem.2002.13.6.653
  10. Razmi, A.M., Bakhtyar, R., Firoozabadi, B. and Barry, D.A. (2013), "Experiments and numerical modeling of baffle configuration effects on the performance of sedimentation tanks", Can. J. Civil Eng., 40, 140-150. https://doi.org/10.1139/cjce-2012-0176
  11. Razmi, A.M., Firoozabadi, B. and Ahmadi, G. (2009), "Experimental and Numerical Approach to Enlargement of Performance of Primary Settling Tanks", J. Appl. Fluid Mech., 2, 1-13.
  12. Shad, H., Adnan, A., Pesaran Behbahani, H. and Vafaei, M. (2016), "Efficiency of TLDs with bottom-mounted baffles in suppression of structural responses when subjected to harmonic excitations", Struct. Eng. Mech., 60, 131-148. https://doi.org/10.12989/sem.2016.60.1.131
  13. Shahrokhi, M., Rostami, F., Md Said, M.A. and Syafalni, S. (2011b), "Numerical modeling of the effect of the baffle location on the flow field, sediment concentration and efficiency of the rectangular primary sedimentation tanks", World Appl. Sci. J., 15 (9), 1296-1309.
  14. Shahrokhi, M., Rostami, F., Md Said, M.A. and Syafalni, S. (2011c), "Numerical simulation of influence of inlet configuration on flow pattern in primary rectangular sedimentation tanks", World Appl. Sci. J., 15(7), 1024-1031.
  15. Shahrokhi, M., Rostami, F., Md Said, M.A. and Syafalni, S. (2013), "Numerical modeling of baffle location effects on the flow pattern of primary sedimentation tanks", Appl. Math. Model., 37, 4486-4496. https://doi.org/10.1016/j.apm.2012.09.060
  16. Shahrokhi, M., Rostami, F., Md Said, M.A., Sabbagh Yazdi, S.R. and Syafalni, S. (2012), "The effect of number of baffles on the improvement efficiency of primary sedimentation tanks", Appl. Math. Model., 36, 3725-3735. https://doi.org/10.1016/j.apm.2011.11.001
  17. Shetab-Boushehri, S.N., Mousavi, S.F. and Shetab-Boushehri, S.B. (2010), "Design of settling basins in irrigation network using simulation and mathematical programming", J. Irrigat. Drain. Eng., ASCE, 136, 2.99-106. https://doi.org/10.1061/(ASCE)IR.1943-4774.0000148
  18. Swamee, P.K. and Tyagi, A. (1996), "Design of class-I sedimentation tanks", J. Environ. Eng., 120, 71-73.
  19. Tamayol, A. and Firoozabadi, B. (2006), "Effects of turbulent models and baffle position on hydrodynamics of settling tanks", J. Scientia Iranica, 13, 255-260.
  20. Tamayol, A., Firoozabadi, B. and Ahmadi, G. (2008), "Determination of settling tanks performance using a eulerianlagrangian method", J. Appl. Fluid Mech., 1, 43-54.
  21. Tamayol, A., Firoozabadi, B. and Ashjari, A. (2010), "Hydrodynamics of secondary settling tanks and increasing their performance using baffles", Environ. Eng., ASCE, 136, 32-39. https://doi.org/10.1061/(ASCE)EE.1943-7870.0000126
  22. Wang, W., Peng, Y., Zhou, Y. and Zhang, Q. (2016), "Liquid sloshing in partly-filled laterally-excited cylindrical tanks equipped with multi baffles", Appl. Ocean Res., 59, 543-563. https://doi.org/10.1016/j.apor.2016.07.009