Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30184
Effect of Flowrate and Coolant Temperature on the Efficiency of Progressive Freeze Concentration on Simulated Wastewater

Authors: M. Jusoh, R. Mohd Yunus, M. A. Abu Hassan

Abstract:

Freeze concentration freezes or crystallises the water molecules out as ice crystals and leaves behind a highly concentrated solution. In conventional suspension freeze concentration where ice crystals formed as a suspension in the mother liquor, separation of ice is difficult. The size of the ice crystals is still very limited which will require usage of scraped surface heat exchangers, which is very expensive and accounted for approximately 30% of the capital cost. This research is conducted using a newer method of freeze concentration, which is progressive freeze concentration. Ice crystals were formed as a layer on the designed heat exchanger surface. In this particular research, a helical structured copper crystallisation chamber was designed and fabricated. The effect of two operating conditions on the performance of the newly designed crystallisation chamber was investigated, which are circulation flowrate and coolant temperature. The performance of the design was evaluated by the effective partition constant, K, calculated from the volume and concentration of the solid and liquid phase. The system was also monitored by a data acquisition tool in order to see the temperature profile throughout the process. On completing the experimental work, it was found that higher flowrate resulted in a lower K, which translated into high efficiency. The efficiency is the highest at 1000 ml/min. It was also found that the process gives the highest efficiency at a coolant temperature of -6 °C.

Keywords: Freeze concentration, progressive freeze concentration, freeze wastewater treatment, ice crystals.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1083913

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1750

References:


[1] Holt, S. (1999), The Role of Freeze Concentration in Waste Water Disposal, Filtration and Separation Journal, 34 - 35.
[2] Miyawaki O., Liu L., Shirai Y., Sakashita S. and Kagitani K. (2005). Tubular ice system for scale-up of progressive freeze-concentration. Journal of Food Engineering. Vol (69): 107-113
[3] Rogers, A., 1999, Freeze Concentration in Hazardous Wastewater Management, The Challenge: Establishing the Best Hazardous Wastewater Management Approach, Techapplication Bulletin, Ellectric Power Research Institute, USA.
[4] Halde, R. (1979). Concentration of impurities by progressive freezing. Water Research 14, 575-580.
[5] Muller, M., & Sekoulov, I. (1992). Waste water reuse by freeze concentration with a falling film reactor. Water Science and Technology, 26, 1475-1482.
[6] Ruemekorf, R (1994). Freeze concentration: its application in hazardous wastewater treatment. J. Environmental Science and Pollution Control Ser, 7, 513-524.
[7] Partyka, V. (1986) Freezing for wastewater recovery. Metal Finishing, 84(11), 55-57
[8] Shirai, Y. (1998). Conditions of producing an ice layer with high purity for freeze wastewater treatment. J. of Food Engineering 38, 297-308.
[9] Gu, X., Suzuki, T., and Miyawaki, O. (2005). Limiting Partition Coefficient in Progressive Freeze Concentration. Journal of Food Science. Vol (70): 546-51.
[10] Widehem P. and Cochet N. (2003). Pseudomonas syringae as an ice nucleator-application to freeze-concentration. Process Biochemistry. Vol (39): 405-410.
[11] Kagitani, K. and Hayakawa, K. (2006). Method of controlling pregressive freeze concentration, US Patent, US7017367B2.
[12] Vaz, D. and Castanheira, I. (2000), Uncertainty budgets and mpes in refractometry: A project Study, OIML bulletin Volume XLI Number 4, 8-11.
[13] Ramos, F. A., Delgado, J.L., Bautista, E., Morales, A. L. and Duque, C. (2005). Changes in volatiles with the application of progressive freeze concentration to Andes berry (Rubus glaucus Benth), Journal of Food Engineering 69, 291-297.
[14] Wakisaka, M., Shirai, Y. and Sakashita, S. (2001) Chemical Engineering and Processing 40, 201-208.
[15] Flesland, O. (1995). Freeze concentration by layer crystallization. Drying Technology, 13(8-9), 1713-1739.
[16] Chen, P., Chen X. D. And Free, K. W. (1998) Solute inclusion in ice formed from sucrose solutions on a sub-cooled surface - an experimental study, Journal of Food Engineering 38, 1-13.