Abstract

The drag reduction efficiency of Polyacrylamide has been tested in this study with different parameters using rotating disc apparatus. The polymer is tested at various concentrations (500, 700, 1000, 1500 and 2000) ppm and under turbulent conditions at different rotation speed up to 3000 rpm. The results show that maximum percent of drag reduction is (28, 30, 33, 35 and 36) % for the above concentrations respectively. The mechanical degradation of the polymer with time is also investigated and analyzed using empirical exponential decay function. The fractional exponential decay equation was found to fit the experimental data of low polymer concentration, while better fitting of single exponential decay model is found for experimental data of higher polymer concentration. The drag reduction decrease with increasing polymer concentration.

Keywords:

Degradation, drag reduction, polyacrylamide, polymer, RDA,

References

1. Bello, J.B., A.J. Müller and A.E. Sáez, 1996. Effect of intermolecular cross links on drag reduction by polymer solutions. Polym Bull., 36(1): 111-118.
   CrossRef    
2. Brostow, W., 1983. Drag reduction and mechanical degradation in polymer solutions in flow. Polymer, 24(5): 631-638.
   CrossRef' target='_blank'>CrossRef    
3. Brostow, W., H. Ertepinar and R.P. Singh, 1990. Flow of dilute polymer solutions: Chain conformations and degradation of drag reducers. Macromolecules, 23: 5109-5118.
   CrossRef    
4. Choi, H.J. and M.S. Jhon, 1996. Polymer-induced turbulent drag reduction. Ind. Eng. Chem. Res., 35(9): 2993-2998.
   CrossRef    
5. Choi, H.J., C.A. Kim and M.S. Jhon, 1999. Universal drag reduction characteristics of polyisobutylene in a rotating disk apparatus. Polymer, 40(16): 4527-4530.
   CrossRef    
6. Choi, H.J., C.A. Kim, J.I. Sohn and M.S. Jhon, 2000. An exponential decay function for polymer degradation in turbulent drag reduction. Polym. Degrad. Stabil., 69(3): 341-346.
   CrossRef    
7. Dschagarowa, E. and G. Menning, 1977. Rheol. Acta, 16: 309.
   CrossRef    
8. Horn, A.F. and E.W. Merrill, 1984. Midpoint scission of macromolecules in dilute solution in turbulent flow. Nature, 312: 140-141.
   CrossRef    
9. Hunston, D.L. and J.L. Zakin, 1980. Flow-assisted degradation in dilute polystyrene solutions. Polym. Eng. Sci., 20(7): 517-523.
   CrossRef    
10. Kim, C.A., K. Lee, H.J. Choi, C.B. Kim, K.Y. Kim and M.S. Jhon, 1997. Universal characteristics of drag reducing polyisobutylene in kerosene. J. Macromol. Sci. A, 34(4): 705-711.
    CrossRef    
11. Kim, C.A., J.T. Kim, K. Lee, H.J. Choi and M.S. Jhon, 2000. Mechanical degradation of dilute polymer solutions under turbulent flow. Polymer, 41(21): 7611-7615.
    CrossRef    
12. Kim, O.K., T. Long and F. Brown, 1986. An unusual coil deformation of polyacrylicacid induced by high shear flow. Polym. Commun., 27: 71-73.
    
13. Little, R.C., 1971. Drag reduction in capillary tubes as a function of polymer concentration and molecular weight. J. Coll. Interf. Sci., 37(4): 811-818.
    CrossRef    
14. Moussa, T. and C. Tiu, 1994. Factors affecting polymer degradation in turbulent pipe flow. Chem. Eng. Sci., 49(10): 1681-1692.
    CrossRef    
15. Nakano, A. and Y. Minoura, 1975. Effects of solvent and concentration on scission of polymers with high-speed stirring. J. Appl. Polym. Sci., 19(8): 2119-2130.
    CrossRef    
16. Sohn, J.I., C.A. Kim, H.J. Choi and M.S. Jhon, 2001. Drag-reduction effectiveness of xanthan gum in a rotating disk apparatus. Carbohyd. Polym., 45(1): 61-68.
    CrossRef    
17. Sung, J.H., S.T. Lim, C.A. Kim, H.J. Chung and H.J. Choi, 2004. Mechanical degradation kinetics of poly(ethylene oxide) in a turbulent flow. Korea-Aust. Rheol. J., 16(2): 57-62.
    
18. Virk, P.S., E.W. Merrill, H.S. Mickley, K.A. Smith and E.L. Mollo-Christensen, 1967. The Toms phenomenon: Turbulent pipe flow of dilute polymer solutions. J. Fluid Mech., 30(2): 305-328.
    CrossRef    

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