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Articles

Vol. 6 (2019)

Design and Evaluation of a Concentrated Solar-Powered Thermal-Pasteurization System

DOI
https://doi.org/10.31875/2410-2199.2019.06.4
Submitted
January 17, 2019
Published
2019-01-17

Abstract

A device has been designed, constructed, and tested for heating fluids using solar energy. The device heats water to levels to kill pathogens by a parabolic reflecting surface that concentrates solar energy along an axis. Among the components that increase the thermal performance of the system is a thermally actuated valve, which controls the temperature and the thermal exposure duration of the fluid to cause deactivation of targeted pathogens. Also, a novel fluid-to-fluid heat exchanger arranged in counter flow is used.
Experiments were performed with a water solution containing non-pathogenic Escherichia coli K-12 MG1655 (E. coli) bacteria. The results showed that the system is capable of pasteurization to levels where no living pathogens were detected in the heated fluid. The experiments were carried out over a wide range of temperatures and exposure durations to test the device and the underlying mathematical model. E. coli log reductions greater than 1 were achieved in all cases and it is shown that arbitrary values of reduction can be achieved with appropriate temperature/time settings.

References

  1. World Health Organization, Progress on Drinking Water and Sanitation, Joint Monitoring Programme Update 2012, World Health Organization: UNICEF, (2012).
  2. JD. Burch and KE. Thomas, An overview of water disinfection in developing countries and the potential for solar thermal water pasteurization, National Renewable Energy Laboratory, NREL/TP-550-23110, (1998).
  3. JD. Burch and K.E. Thomas, Water disinfection for developing countries and potential for solar thermal pasteurization, Solar Energy, 1998; 64: 87-97. https://doi.org/10.1016/S0038-092X(98)00036-X
  4. L. Liu, HL. Johnson, S. Cousens, et al., Child health epidemiology reference group of WHO and UNICEF, Lancet, 2012; 379: 2151-2161. https://doi.org/10.1016/S0140-6736(12)60560-1
  5. A. Gadgil, Drinking water in developing countries, Annual Reviews of Energy and the Environment, 1998; 23: 253-286. https://doi.org/10.1146/annurev.energy.23.1.253
  6. R. Feachem, DJ. Bradley, and DD. Mara, Sanitation and disease: Health aspects of excreta and wastewater management, John Wiley and Sons, New York, NY (1983).
  7. L. Huisman and WE. Wood, Slow sand filtration, World Health Organization, Geneva, (1974).
  8. C. Svrek and DW. Smith, Cyanobacteria toxins and the current state of knowledge on water treatment options: a review, Journal of Environmental Engineering and Science, 2004; 3: 155-185. https://doi.org/10.1139/s04-010
  9. JL. Zimmer and RM. Slawson, Potential repair of Escherichia coli DNA following exposure to UV radiation from both medium- and low-pressure UV sources used in drinking water treatment, Applied Environmental Microbiology, 2002; 68: 3293-3299. https://doi.org/10.1128/AEM.68.7.3293-3299.2002
  10. DC. Walker, SV. Len, and B. Sheehan, Development and evaluation of a reflective solar disinfection pouch for treatment of drinking water, Applied Environmental Microbiology, 2004; 70: 2545-2550. https://doi.org/10.1128/AEM.70.4.2545-2550.2004
  11. DA. Ciochetti and RH. Metcalf, Pasteurization of naturally contaminated water with solar energy, Applied Environmental Microbiology, 1984; 47: 223-228.
  12. TS. Saitoh and HH. El-Ghetany, Solar water-sterilization system with thermally controlled flow, Applied Energy, 1999; 64: 387-399. https://doi.org/10.1016/S0306-2619(99)00086-0
  13. LF. Caslake, et al., Disinfection of contaminated water by using solar irradiation, Applied and Environmental Microbiology 2004; 70: 1145-1150. https://doi.org/10.1128/AEM.70.2.1145-1150.2004
  14. BD. Plourde, J.P.Abraham, and W.J. Minkowycz, Continuous flow solar thermal pasteurization of drinking water: Methods, devices, microbiology, and analysis, Renewable Energy, 2015; 81: 795-803. https://doi.org/10.1016/j.renene.2015.03.086
  15. BD. Plourde, JP. Abraham, DR. Plourde, A. Gikling, and R. Pakonen, 2018, Dual-Axis Tracking Device, U.S. Patent # 10168412 (2018).
  16. AT. Spinks, RH. Dunstan, T. Harrison, P. Coombes, and G. Kuczera, Thermal inactivation of water-borne pathogenic and indicator bacteria at sub-boiling temperatures, Water Research, 2006; 40: 1326-1332. https://doi.org/10.1016/j.watres.2006.01.032
  17. US. Food and Drug Administration, Kinetics of microbial inactivation for alternative for processing technologies – overarching principles: Kinetics and pathogens of concern for all technologies, http://www.fda.gov/Food/FoodScienceResearch/SafePractice sforFoodProcesses/ucm100198.htm
  18. GK. Rijal and RS. Fujioka, Synergistic effect of solar radiation and solar heating to disinfect drinking water sources, Water Science and Technology, 2001; 43: 155-162. https://doi.org/10.2166/wst.2001.0728
  19. WS. Duff and DA. Hodgson, A simple high efficiency solar water purification system, Solar Energy, 2005; 79: 25-32. https://doi.org/10.1016/j.solener.2004.10.005
  20. AM. Abdel Dayem, HH El-Ghetany, GE. El-Taweet, and MM. Kamel, Thermal performance and biological evaluation of solar water disinfection systems using parabolic trough collectors, Desalination and Water Treatment, 2011; 36:119-128. https://doi.org/10.5004/dwt.2011.2227
  21. N. Safapour and R.H. Metcalf, Enhancement of solar water pasteurization with reflectors, Applied and Environmental Microbiology, 1999; 65: 859-861.
  22. N. Fraidenraich, C. Tiba, BB. Brandao, and OB. Vilela, Analytic solutions for the geometric and optical properties of stationary compound parabolic concentrators with fully inverted V receiver, Solar Energy, 2008; 82: 132-143. https://doi.org/10.1016/j.solener.2007.06.012
  23. T. Tao, Z. Hongfei, H. Kaiyan, and A. Mayere, 2011 A new trough solar concentrator and its performance analysis, Solar Energy, 2011; 85: 198-207. https://doi.org/10.1016/j.solener.2010.08.017
  24. TL. Bergman, A. Lavine, FP. Incropera, and DP. DeWitt, Introduction to Heat and Mass Transfer, 6th edition, John Wiley and Sons, New Jersey (2011).
  25. EM. Sparrow, JP. Abraham, and JCK. Tong, Archival correlations for average heat transfer coefficients for noncircular and circular cylinders and for spheres in crossflow, International Journal of Heat and Mass Transfer, 2004; 47: 5285-5296. https://doi.org/10.1016/j.ijheatmasstransfer.2004.06.024
  26. AV. Hollands and K.G.T Hassani, On natural convection heat transfer from three-dimensional bodies of arbitrary shape, Journal of Heat Transfer, 1989; 111: 363-371. https://doi.org/10.1115/1.3250686
  27. JP. Abraham and EM. Sparrow, Three dimensional laminar and turbulent natural convection in a continuously/discretely wall-heated enclosure containing a thermal load, Numerical Heat Transfer A, 2003; 44: 105-125. https://doi.org/10.1080/713838194
  28. JM. Gorman, E.M. Sparrow, and J.P. Abraham, Differences between measured pipe wall surface temperatures and internal fluid temperatures, Case Studies in Thermal Engineering, 2013; 1: 13-16. https://doi.org/10.1016/j.csite.2013.08.002
  29. JCK. Tong, JP. Abraham, JMY. Tse, WJ. Minkowycz, and EM. Sparrow, New archive of heat transfer coefficients from square and chamfered cylinders in crossflow, International Journal of Thermal Sciences, 2016; 105: 218-223. https://doi.org/10.1016/j.ijthermalsci.2016.03.008
  30. M. Li, Y. Jiang and CFM. Coimbra, on the determination of atmospheric longwave irradiance under all-sky conditions, Solar Engineering, 2017; 144: 40-48. https://doi.org/10.1016/j.solener.2017.01.006