Behaviour of Ice Crystal Growth in a Vertical Finned Cylindrical Freeze Concentrator

2014 ◽  
Vol 695 ◽  
pp. 451-454 ◽  
Author(s):  
Amran Nurul Aini ◽  
Samsuri Shafirah ◽  
Norzita Ngadi ◽  
Zaki Yamani Zakaria ◽  
Jusoh Mazura
Keyword(s):  
Crystal Growth ◽  
Production Rate ◽  
Glucose Solution ◽  
Circulation Time ◽  
Coolant Temperature ◽  
Operating Parameters ◽  
Water Recovery ◽  
Ice Crystal ◽  
Freeze Concentration ◽  
Ice Production

Behaviours of ice crystal growth at two different operating parameters namely coolant temperature and circulation time were investigated for progressive freeze concentration (PFC) of glucose solution through a vertical finned crystallizer (VFC). Two determinant parameters which are ice production rate (mu), and water recovery (WR) were used to illustrate the behaviours of ice crystal growth in this study. From the result, higher ice production rate (mu) and water recovery (WR) were achieved at lower coolant temperature. On the other hand, longer circulation time resulted in lower ice production rate (mu), but at the same time increased the water recovery (WR). The maximum ice production rate (mu) and water recovery (WR) attained through this study were 1.522 gm-2s-1 and 51.131 %, respectively.

Effect of Coolant Temperature on Desalination Process via Progressive Freeze Concentration

2014 ◽  
Vol 695 ◽  
pp. 443-446 ◽  
Author(s):  
Ab. Hamid Farah Hanim ◽  
A.Rahim Norfatiha ◽  
Norzita Ngadi ◽  
Zaki Yamani Zakaria ◽  
Jusoh Mazura
Keyword(s):  
System Performance ◽  
New Technologies ◽  
Pure Water ◽  
Coolant Temperature ◽  
Clean Water ◽  
Ice Crystal ◽  
Freeze Concentration ◽  
Salinity Reduction ◽  
The World ◽  
Crystal Block

The world is still suffering from a shortage of clean water supply and the problem is expected to become more serious in the future. Consequently, researchers have been trying to find the best solution to address this problem by introducing new desalination technologies that are able to accommodate the demand for clean water which is increasing from time to time. One of the new technologies introduced is the desalination of seawater through freeze concentration. In this study, progressive freeze concentration (PFC) is implemented to produce pure water in the form of ice crystal block and leave behind a higher concentration solution. The effect of coolant temperature was investigated and the efficiency of the system was reviewed based on the value of effective partition constant, K which is defined by the ratio of solute in ice and liquid phase. The low value of K leads to the best efficiency for the system. Apart from that, the efficiency, E% and salinity reduction were also calculated in order to determine the system performance.

Progressive Freeze Concentration of Coconut Water: Effect of Coolant Temperature on Process Efficiency and Heat Transfer

2014 ◽  
Vol 695 ◽  
pp. 447-450
Author(s):  
Safiei Nor Zanariah ◽  
Mohamed Nor Noor Naimah ◽  
Norzita Ngadi ◽  
Zaki Yamani Zakaria ◽  
Jusoh Mazura
Keyword(s):  
Heat Transfer ◽  
Operation Time ◽  
Coconut Water ◽  
Process Efficiency ◽  
Coolant Temperature ◽  
Ice Crystal ◽  
Water Effect ◽  
Freeze Concentration ◽  
Overall Heat Transfer Coefficient ◽  
Heat Transfer Efficiency

In this research, coconut water was concentrated by applying progressive freeze concentration (PFC) using coil crystallizer. Overall heat transfer coefficient (U) was analyzed from the process by varying different coolant temperature values since both of them are closely related. In this case, heat transfer efficiency depends strongly on ice crystal formed on the inner cooled surface and is explained theoretically from that angle. At optimum flowrate, operation time and initial concentration best results were observed at-10oC of coolant temperature where the concentration efficiency and effective partition constant (K) obtained were 48% and 0.2 respectively. Meanwhile, U obtained at the first and second stages were 183.0046 W/m2oC but dropped at lower value at later stage at 154.9625 W/m2oC due to ice fouling.

Progressive Freeze Concentration for Wastewater Treatment from Food Industry

2019 ◽  
Vol 797 ◽  
pp. 55-64 ◽  
Author(s):  
Farah Hanim Ab Hamid ◽  
Siti Nurajjar Jami
Keyword(s):  
Wastewater Treatment ◽  
Food Industry ◽  
Pure Water ◽  
Coolant Temperature ◽  
Wastewater Sample ◽  
Ice Crystal ◽  
K Value ◽  
Freeze Concentration ◽  
Simulated Wastewater ◽  
Crystal Block

Crystallization technique is one of the potential techniques to deal with wastewater treatment. In this work, progressive freeze concentration (PFC) technique was studied for its effectiveness in wastewater treatment from food industry. In PFC, pure water is produced in the form of ice crystal block and leave behind a higher concentration solution. The effect of coolant temperature and stirring speed on the effective partition constant (K) and solute recovery (Y) were investigated. Glucose solution was used as simulated wastewater sample. The best conditions were found at the moderate coolant temperature of -10°C and maximum stirring speed of 500 rpm, resulted in the lowest K value and highest Y, lead to the highest efficiency on the wastewater treatment.

scholarly journals Effect of Operating Parameters and Foreign Ions on the Crystal Growth of Calcium Carbonate during Scale Formation: An Overview

2020 ◽  
Author(s):  
Atef Korchef
Keyword(s):  
Drinking Water ◽  
Crystal Growth ◽  
Calcium Carbonate ◽  
Large Scale ◽  
Natural Waters ◽  
Scale Formation ◽  
Operating Parameters ◽  
Water Recovery ◽  
Water And Wastewater Treatment ◽  
Foreign Ions

Due to the insufficiency of freshwater resources and to supply the drinking water populations, many desalination processes such as reverse osmosis, electrodialysis and distillation are widely used. However, these processes are of large-scale consumers of energy and confronted with various problems such as corrosion and scale formation. In most cases, scales are made of calcium carbonate CaCO3. In the present chapter, an overview on the effect of operating parameters such as temperature, pH and supersaturation on the precipitation kinetics, microstructure, and polymorphism of CaCO3 is given. Additionally, I put special emphasis on the effect of foreign ions such as magnesium, sulphate, and iron ions on CaCO3 precipitation since they are present at significant concentrations in natural waters. Also, the mechanisms by which these ions affect the crystal growth of CaCO3 were pointed out. Knowledge about these operating parameters as well as the effects of foreign ions allow elucidating the polymorphs growth during water treatment. The control of these operating parameters allows reducing scale formation during drinking water and wastewater treatment. The economic impact is of greatest importance since this favorably affects the treatment costs, increases the equipment life, and allows enhanced product water recovery.

Desalination of seawater through progressive freeze concentration using a coil crystallizer

2015 ◽  
Vol 15 (3) ◽  
pp. 625-631 ◽  
Author(s):  
Farah Hanim Ab. Hamid ◽  
Norfatiha A. Rahim ◽  
Anwar Johari ◽  
Norzita Ngadi ◽  
Zaki Yamani Zakaria ◽  
...  
Keyword(s):  
Heat Transfer ◽  
New Technologies ◽  
Pure Water ◽  
Coolant Temperature ◽  
Clean Water ◽  
Ice Crystal ◽  
Freeze Concentration ◽  
Overall Heat Transfer Coefficient ◽  
Increasing Demand ◽  
Crystal Block

In this century, the shortage of clean water supply is an issue of concern and the problem is expected to become more serious in the future. Consequently, researchers are trying to find the best solution to address this problem by introducing new desalination technologies that are able to accommodate the increasing demand for clean water. One of the new technologies introduced is desalination of seawater through freeze concentration. In this study, progressive freeze concentration (PFC) was implemented to produce pure water in the form of an ice crystal block, leaving behind higher concentration seawater using a coil crystallizer. The effect of operating parameters such as initial concentration and coolant temperature were investigated. Meanwhile, the efficiency of the system was reviewed based on the value of the effective partition constant K which is defined by the ratio of solute in ice and liquid phase. A low value of K indicates when the system is most efficient. In addition, the results for the overall heat transfer coefficient are also presented to observe the heat transfer involved in the system.

scholarly journals Synthetic insect antifreeze peptides modify ice crystal growth habit

CrystEngComm ◽  
2017 ◽  
Vol 19 (16) ◽  
pp. 2163-2167 ◽  
Author(s):  
Charles H. Z. Kong ◽  
Ivanhoe K. H. Leung ◽  
Vijayalekshmi Sarojini
Keyword(s):  
Crystal Growth ◽  
Small Molecule ◽  
Growth Habit ◽  
Antifreeze Protein ◽  
Ice Crystals ◽  
Ice Crystal ◽  
Antifreeze Peptides ◽  
Antifreeze Activity

Synthetic antifreeze peptides based on the hyperactive antifreeze protein modify the shape of ice crystals and show enhanced antifreeze activity with the addition of a small molecule.

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