Advances and recent developments in thermal drying for bio-origin and agricultural products

Stewart Postharvest Review

Volumn 4, Issue 1, 2008, Pages

  Chung, Lim Law ^a   Waje, Sunil Shivram ^b   Thorat, Bhaskar Narayan ^b   Mujumdar, Arun Sadashiv ^c  

^a UNIVERSITY OF NOTTINGHAM MALAYSIA CAMPUS   (Malaysia)

^b UNIVERSITY OF MUMBAI   (India)

^c NATIONAL UNIVERSITY OF SINGAPORE   (Singapore)

Author keywords

Agitated fluidised bed drying; Freeze drying; Heat pump drying; Intermittent drying; Microwave vacuum drying; Solar drying; Spray drying; Superheated steam drying

Indexed keywords

EID: 41949136524     PISSN: None     EISSN: 17459656     Source Type: Journal    
DOI: 10.2212/spr.2008.1.1     Document Type: Review

References (179)

1. Mujumdar AS. Classification and selection of industrial dryers. In: Guide To Industrial Drying: Principles, Equipment and New Developments. Edited by A.S. Mujumdar (Editor). Mumbai: Colour Publication Pvt. Ltd.; 2004 pp. 23-36. ** This is one of the important references on classification and selection of industrial dryers. The author classified the dryers according to various criteria, parameters and operating modes. Guide and tips also given in this book chapter on selection of dryers.
2. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 137-150. ** An overview on indirect dryers that includes classification and selection, descriptions on various types of indirect dryer as well as design and modelling.
3. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 151-172. * Types of rotary dryer, model and design are given in this handbook chapter as well as case studies
4. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 173-202. ** A comprehensive overview of fluidised bed dryers that covers a wide range of topics. The topics include heat transfer, mathematical models, classification and selection, descriptions of various modified fluidised bed dryers and design.
5. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 203-214. * This handbook chapter covers types of drum dryer and their operating principles.
6. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 215-256. ** An extensive overview on operating principles of spray drying systems, components, design considerations, modelling and new developments.
7. Master K. Spray Drying Handbook. New York: John Wiley & sons Inc.; 1991. ** A good source for those who wish to master spray drying.
8. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 257-284. ** This handbook chapter covers a wide range of topics that are related to freeze drying, namely, operating stages, various types of freeze drying, description of industrial freeze dryers, costs and modelling.
9. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 307-362. ** A comprehensive overview on various topics that are related to solar drying. This handbook chapter covers various types of solar dryer, operating principles, components, simulations, and controls.
10. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 363-384. * This chapter covers findings obtained from spouted bed drying of various agricultural products and chemicals
11. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 385-396. * This chapter covers the design of impingement dryers, nozzles, and effect of various parameters.
12. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 397-410. * An overview on the design and modelling of pneumatic and flash dryers.
13. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 411-422. * A chapter that covers dryer configurations, components, selection and sizing as well as controls.
14. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 423-438.
15. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 439-452. * An overview that describes the processing of various materials using superheated steam as the drying medium.
16. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 453-520. ** An extensive overview that covers many special drying techniques and novel dryers that have been developed in recent years. A must read handbook chapter for those who wish to investigate, use and try new ideas in thermal drying.
17. th International Drying Conference 2002: 1-18. ** This paper is an important source for learning the recent trends in thermal drying and future R&D directions.
18. Mujumdar AS. Global R&D needs and opportunities. Guide to Industrial drying: Principles, Equipment and New Developments, 2004: 271-292. ** This paper is an important source for learning the recent trends in thermal drying and future R&D directions.
19. Mujumdar AS. An overview of innovation in industrial drying: current status and R&D needs. Transport Porous Media 2007: 66: 3-18. ** This paper is an important source for learning the recent trends in thermal drying and future R&D directions.
20. Arun S. Mujumdar and Wu Zhonghua. Thermal Drying Technologies - Cost-Effective Innovation Aided by Mathematical Modeling Approach. Drying Technology 2008: 26: 1-9. ** This paper is an important source for learning the recent trends in thermal drying and future R&D directions
21. Nguyen CN and Kunze OR. Fissures related to post-drying treatments in rough rice. Cereal Chemistry 1984: 61: 63-68.
22. Li YB, Cao CW, Yu QL and Zhong QX. Study on rough rice fissuring during intermittent drying. Drying Technology 1999: 17: 1779-1793.
23. Iguaz A, Rodriguez M and Virseda P. Influence of handling and processing of rough rice on fissures and head rice yields. Journal of Food Engineering 2006: 77: 803-809.
24. Cihan A and Ece MC. Liquid diffusion model for intermittent drying of rough rice. Journal of Food Engineering 2001: 49: 327-331.
25. Pan YK, Zhao LJ, Dong X, Mujumdar AS and Kudra T. Intermittent drying of carrot in a vibrated fluid bed: effect on product quality. Drying Technology 1999: 17: 2323-2340. * Drying of diced carrot was studied experimentally in a laboratory batch vibrated fluidised bed dryer. A mathematical model of the reaction kinetic of degradation of β-carotene was developed and it fitted well the experimental data. It was found that intermittent drying can reduce degradation of β-carotene and shorten the effective drying time and yet did not affect the rehydration capacity.
26. Thomkapanich O, Suvarnakuta P and Devahastin S. Study of intermittent low-pressure superheated steam and vacuum drying of a heat-sensitive material. Drying Technology 2007: 25: 205-223. ** The authors of this paper investigated the effects of intermittency and onperiod setting drying temperature on the drying kinetics and quality of banana chips. The banana chips underwent intermittent low pressure superheated steam drying and vacuum drying. The results obtained in this investigation were compared with the results obtained from continuous drying. It was found that intermittency shortened the drying time thus reducing the energy consumption. Intermittency did not give much difference in the product quality (in terms of colour, shrinkage) as compared with conventional continuous drying. However it was found that intermittent temperature drying reduced the product lightness but preserved the ascorbic acid content. Whereas intermittent pressure drying gave deteriorating colour, more shrinkage and degraded ascorbic acid content.
27. Xing H, Takhar PS, Helms G and He B. NMR imaging of continuous and intermittent drying of pasta. Journal of Food Engineering 2007: 78: 61-68. * The authors adapted nuclear magnetic resonance imaging technique and used it to measure moisture distribution within samples. It was found that a wet layer near the surface of pasta was observed during intermittent drying but the surface layer remained dry during continuous drying. The wet layer near the surface caused greater amount of moisture loss during intermittent drying than continuous drying. It was concluded that the time step size and drying air conditions affected the performance of intermittent drying.
28. Jumah R, Al-Kteimat E, Al-Hamad A and Telfah E. Constant and Intermittent Drying Characteristics of Olive Cake. Drying Technology 2007: 25: 1421-1426 .
29. Bon J and Kudra T. Enthalpy-driven optimization of intermittent drying. Drying Technology 2007: 25: 523-532. * The authors developed a tool to optimise the intermittent drying of biological materials in a batch rotating jet spouted bed dryer. Average enthalpy gain of the drying product was considered as the objective function and it has to be minimised. A diffusion model was used to estimate the objective function. The results show that the optimisation of intermittent drying improved the energy performance and offered better product quality due to lower enthalpy gain.
30. Jumah R. Flow and drying characteristics of a rotating jet spouted bed dryer. PhD thesis, McGill University, Montreal, 1995.
31. Jumah R, Mujumdar AS and Raghavan GSV. A mathematical model for constant and intermittent batch drying of grains in a novel rotating jet spouted bed. In: Mathematical Modelling and Numerical Techniques in Drying Technology. Edited by I. Turner and A.S. Mujumdar (Editors). New York: Marcel Dekker; 1996 pp. 339-380
32. Madamba PS and Yabes RP. Determination of the optimum intermittent drying conditions for rough rice (Oryza sativa, L.). Lebensm.-Wiss. u.-Technology 2005: 38: 157-165. * The authors tested intermittent drying of rough at temperature range 35-55°C. It was found that intermittent at 45°C for 2 h gave high milling recovery, high head rice ratio, short drying time, high grain hardness, high germination ratio, high degree of whiteness and low cracked grains ratio.
33. Aquerreta J, Iguaz A, ArroquiC and Vírseda P. Effect of high temperature intermittent drying and tempering on rough rice quality. Journal of Food Engineering 2007: 80:611-618.
34. Chua KJ, Mujumdar AS, Hawlader MNA, Chou SK and Ho JC. Batch drying of banana pieces - effect of stepwise change in drying air temperature on drying kinetics and product colour. Food Research International 2001: 34: 721-731. * Two-stage heat pump drying and stepwise change drying tempering were used to dehydrate banana slices in this study. It was found that the strategy used in this study enhanced the drying kinetics as well as the colour of the dried banana.
35. Sun L, Islam MR, Ho JC and Mujumdar AS. A diffusion model for drying of a heat sensitive solid under multiple heat input modes. Bioresource Technology 2005: 96: 1551-1560. * Four combinations of heat input on the drying kinetics and energy consumption were simulated. It was found that radiation-coupled convection gave the best performance.
36. Chua KJ, Chou SK, Mujumdar AS, Ho JC and Hon CK. Radiant-convective drying of osmotic treated agro-products: effect on drying kinetics and product quality. Food Control 2004: 15: 145-158. * A combination of intermittent infrared and continuous convection heating was used to dry various osmotically pretreated potato, carrot and banana samples. It was found that the infrared intermittences and heat flux intensity regulation as well as osmotic pretreatment were able to produce premium quality agro-products while maintaining high drying rates.
37. Chua KJ, Mujumdar AS and Chou SK. Intermittent drying of bioproducts - an overview. Bioresource Technology 2003: 90: 285-295. ** This paper provides an overview on intermittent drying that includes the advantages, basic process, classification, research findings from selected results obtained from experiments and mathematical modelling of a variety of biomaterials.
38. Mujumdar AS. Handbook of industrial drying. Ed. AS Mujumdar. New York: CRC Press; Boca Raton, Fl. USA, 2007. 1460 pp ** A bible on thermal drying that covers almost all types of dryers, conventional and novel, fundamentals and drying of various products which include agricultural, herbal, bio-materials, chemical, etc. A must-have drying reference.
39. Prachayawarakorn S, Prachayawasin P and Soponronnarit S. Effective diffusivity and kinetics of urease inactivation and color change during processing of soybeans with superheated-steam fluidized bed. Drying Technology 2004: 22: 2095-2118. ** Influences of temperature and moisture content on diffusional transport property and kinetics of both urease inactivation and colour change during soybean treatment with superheated steam in the temperatures of 120-150°C were investigated. The authors found that increasing temperature as well as moisture content lead to higher diffusion, urease inactivation, and brown pigment formation. The authors also gave suggestions on how to inactivate the urease enzyme while maintaining soybean qualities in terms of protein solubility, lysine and colour. It was suggested to apply two stage drying strategy with superheated steam at temperatures within 120-135°C followed by second stage low temperature heated air drying.
40. Pronyk C, Cenkowski S and Muir WE. Drying foodstuffs with superheated steam. Drying Technology 2004: 22: 899-916. * Drying rates of superheated steam drying of sugar beet pulp was found greater than that obtained from heated air drying under the same operating conditions. The authors observed that superheated steam drying of Asian noodles exhibited better product quality in terms of recovery, adhesiveness, and gumminess but gave deleterious effect on the cutting stress, resistance to compression, and surface firmness. Higher levels of starch gelatinisation and retention of fibre content of spent grains was observed in superheated steam drying too.
41. Jamradloedluk J, Nathakaranakule A, Soponronnarit S and Prachayawarakorn S. Influences of drying medium and temperature on drying kinetics and quality attributes of durian chip. Journal of Food Engineering 2007: 78: 198-205. * Quality of low-fat durian chips dehydrated by hot air drying and superheated steam drying was evaluated. It was found that the drying rate of superheated steam drying was lower. The authors attributed it to the consequence of steam condensation which occurred during an early stage of drying and the formation of thicker dense layer during the superheated steam drying. The authors concluded that superheated steam drying provided products with greater values of redness, yellowness, as well as rehydration capacity but lower values in lightness.
42. Cenkowski S, Pronyk C, Zmidzinska D and Muir WE. Decontamination of food products with superheated steam. Journal of Food Engineering 2007: 83: 68-75. * The effects of superheated steam on grains contaminated with the Fusarium mycotoxin deoxynivalenol and with Geobacillus stearothermophilus spores were investigated. Reductions in deoxynivalenol concentration were achieved at 185°C and 6 min of processing time. This was attributed to thermal degradation. The authors concluded that the use of superheated steam drying is beneficial in reducing the contamination of foods.
43. Barbieri S, Elustondo M and Urbicain M. Retention of aroma compounds in basil dried with low pressure superheated steam. Journal of Food Engineering 2004: 65: 109-115. * Experimental work on the retention of aromatic compounds in fresh vegetables was conducted by the authors, and showed that low pressure superheated steam drying was able to keep the original aroma profile. Air dried products showed a significant deterioration in the content of the aromatic compounds.
44. Shibata H and Ide M. Combined superheated steam and microwave drying of sintered glass beads: drying rate curves. Drying Technology 2001: 19: 2063-2079.
45. Tatemoto Y, Yanoa S, Mawatarib Y, Nodaa K and Komatsuc N. Drying characteristics of porous material immersed in a bed of glass beads fluidized by superheated steam under reduced pressure. Chemical Engineering Science 2007: 62: 471-480. * Drying characteristics and kinetics of porous materials dehydrated using superheated steam with and without fluidisation were studied. It was found that fluidisation reduced the drying time of superheated heated steam drying. Likewise the drying time was also shortened at reduced pressure due to lower boiling point.
46. Devahastin S, Suvarnakuta P, Soponronnarit S and Mujumdar AS. A comparative study of low-pressure superheated steam and vacuum drying of a heat-sensitive material. Drying Technology 2004: 22: 1845-1867. * Product quality of carrot cubes dried in vacuum drying and reduced pressure superheated steam drying was compared. It was found that low-pressure superheated steam drying gave better quality (rehydration ratio and colour) compared with vacuum drying, despite lower drying rates due to poorer convective heat transfer under reduced pressures and longer drying time.
47. Suvarnakuta P, Devahastin S and Mujumdar AS. A mathematical model for low-pressure superheated steam drying of a biomaterial. Chemical Engineering and Processing 2007: 46: 675-683.
48. Kiang CS and Jon CK. Heat pump drying systems. In: Handbook of Industrial Drying. 3rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC Press; 2007 pp.1103-1131. ** The authors provided a detailed classification, working principles, advantages and limitations of HPDs.
49. Alves-Filho O and Strommen I. Performance and improvements in heat pump dryers. Proceedings IDS'96 1996: 405-415.
50. Strommen I, Eikevik TM and Alves-Filho O. Optimum design and enhanced performance of heat pump dryers. Proceedings of the ADC'99 1999: 66-80.
51. Ogura H, Yamamoto T, Kage H, Matsuno Y and Mujumdar AS. Effect of heat Exchange conditions on hot air production by a chemical heat pump dryer using CaO/Ca(OH)2 reaction. Chemical Engineering Journal 2002: 86: 3-10.
52. Ogura H, Ishida H, Kage H and Mujumdar AS. Enhancement of energy efficiency of a chemical heat pump-assisted convective dryer. Drying Technology 2003: 21: 279-292. * In this paper the authors present experimental results to demonstrate the potential for improved heat-recovery/storage and the heat-release/production of hot dry air for batch drying applications using the heat enhancement mode of the CHP. A new laboratory scale experimental CHP dryer system was built utilising the calcium oxide/calcium hydroxide hydration/dehydration reversible reaction.
53. Cardona TD, Driscoll RH, Peterson JL, Srzednicki GS and Kim WS. Optimizing conditions for heat pump dehydration of lactic acid bacteria. Drying Technology 2002: 20: 1611-1632.
54. Waje SS, Phadake J, Pandey R, Malshe VC and Thorat BN. Absorbable gelatine foam: Synthesis and quality analysis. Proceedings of the ADC' 07 2007: 1058-1063. * The authors have compared the economical feasibility and product quality parameters of absorbable gelatin sponge (Surgifoam™) dried using heat pump drying and freeze drying.
55. Stapley A and Rielly C. Advances in unconventional freeze drying technology, Chemical Engineer (London). 2007: 790: 33-35. * The application of a heat pump-assisted sub-atmospheric spray-freeze dryer for drying of pharmaceuticals, biological and food products is reported.
56. Hawlader MNA, Perera CO and Tian M. Comparison of the retention of 6-gingerol in drying of ginger under modified atmospheric heat pump drying and other drying methods. Drying Technology 2006: 24: 51-56. * A HPD using normal air, nitrogen and carbon dioxide was selected to dry sliced West Indian ginger (Zingiber officinale Roscoe) rhizome (3 mm in thickness). Drying characteristics were compared.
57. Hawlader MNA, Perera CO, Tian M and Yeo KL. Drying of guava and papaya: Impact of different drying methods. Drying Technology 2006: 77-87.
58. Alves-Filho O. Combined innovation heat pump drying technologies and new cold extrusion techniques for production of instant foods. Drying Technology 2002: 20: 1541-1557. ** This work describes new technologies and processing line for the production of instant foods as well as the measurements on the properties and quality attributes for raw, intermediate and final instant products.
59. Saensabai P and Prasertsan S. Condensor coil optimization and component matching of heat pump dryer. Drying Technology 2007: 25: 1571-1580.
60. Sarkar J, Bhattacharya S and Ram Gopal M. Transcritical CO2 heat pump dryer: Part 1. Mathematical model and simulation. Drying Technology 2006: 24: 1583-1591.
61. Zhang B, Zhou Y, Ning W and Xie D. Experimental study on energy consumption of combined conventional and dehumidification drying. Drying Technology 2007: 25: 471-474. ** Conventional drying, dehumidification drying, and combined conventional-dehumidification drying of wood were experimentally studied in this article. The advantages of the combined conventional and dehumidification drying are discussed from the experiments results.
62. Mujumdar AS. Drying technologies of the future. Drying Technology 1991: 9: 325-347. ** This paper reviews the recent advances and general trends in drying technologies of industrial interest. Numerous emerging technologies are listed with emphasis on the following five areas: Carver-Greenfield Process for drying of sludges, superheated steam drying, pulse combustion drying, high intensity drying techniques for paper and the novel impinging steam dryers. Potential application areas for the new technologies are identified.
63. Mujumdar AS. Some Recent Developments in Drying Technologies Appropriate for Post-harvest Processing. International Journal of Postharvest Technology and Innovation 2006: 1: 76-92. ** The objective of this paper address is to summarise some of the new developments in drying and examine their potential for application in post-harvest processing at farm or large scale.
64. Chua KJ, Chou SK, Hawlader MNA, Ho JC and Mujumdar AS. On the study of time-varying temperature drying - Effect on drying kinetics and product quality. Drying Technology 2002: 20: 1579-1610.
65. Chua KJ, Mujumdar AS, Chou SK, Hawlader MNA and Ho JC. Heat pump drying of banana, guava and potato pieces: effect of cyclic variations of air temperature on convective drying kinetics and color change. Drying Technology 2000: 18: 1583-1616.
66. Chen G, Banister P, Carrington CG, Velde PT and Burger FC. Design and application of dehumidifier dryer for drying pine cones and pollen catkins. Drying Technology 2002: 20: 1633-1643.
67. Chua KJ, Chou SK, Mujumdar AS, Ho JC and Hawlader MNA. Heat pump drying: Recent developments and future trends. Drying Technology 2002: 20: 1559-1577. ** This review paper focuses on the recent progress made in heat pump drying. An introduction is given on the operating and working principle of the heat pump drying system. Advantages and limitations of heat pump drying are outlined. Two industrial applications in heat pump drying, food and timber, are discussed. New developments in heat pump drying are presented. A section discussing the potential of incorporating advanced heat pump cycles for drying application is also presented.
68. Klocker K, Schmidt EL and Steimle F. A drying heat pump using carbon dioxide as working fluid. Drying Technology 2002: 20: 1659-1671. * The design and construction of a commercial drying heat pump system (batch type cabinet dryer with 12 kW heating capacity and closed air circuit) using the natural working fluid carbon dioxide is shown and experimental results of investigations carried out are presented. Possible energy savings calculated theoretically are given for comparison.
69. Carrington CG and Bannister P. An empirical model for heat pump dehumidifier drier. International Journal Energy Research 1996: 20: 853-869. *The model is used to demonstrate how the performance for the dehumidifier relates to that for the coupled kiln-dehumidifier system.
70. Law CL and Mujumdar AS. Fluidized bed drying. In: Guide to Industrial Drying: Principles, Equipment and New developments. Edited by AS Mujumdar (Editor). India: Colour Publications Pvt. Ltd.; pp. 75-141. ** The authors outlined the various problems in the fluidisation of fine and ultra-fine particles (Group C particles) and suggested the assistance of external means such as vibration, agitation, rotation and centrifugation for enhancing the fluidisation quality of fine particles.
71. Adamiec J. Drying of waste sludges in a fluidized bed dryer with a stirrer. Drying Technology 2002: 20: 839-853. * In this paper some problems of drying of two types of sludge wastes of different form and origin are presented. The laboratory experiments of sludge drying in the fluidised bed dryer with a mixer, fluidised bed hydrodynamics, and the effects and advantages of sludge drying are shown.
72. Reyes A, Eckholt M and Alvarez PI. Drying and heat transfer characteristics for a novel fluidized bed dryer. Drying Technology 2004: 22: 1869-1895. * The authors investigated the use of a fluidised bed dryer with a lateral air flow and mechanical agitation to the drying of sludge from a wastewater treatment plant. Experimental curves of moisture content vs. drying time, as well as heat transfer coefficients and the size characteristics of the products, were determined
73. Kim J and Han GY. Effect of agitation on fluidization characteristics of fine particles in a fluidized bed. Powder Technology 2006: 166: 113-122. * The effect of agitation on the fluidisation characteristics of fine particles was investigated in a fluidised bed with an I.D. of 6 cm and a height of 70 cm. The agitator used was of the pitched-blade turbine type and phosphor particles were employed as the bed material.
74. Moreno RM, Antolín G and Reyes A. Thermal behaviour of forest biomass drying in a mechanically agitated fluidized bed. Latin American Applied Research 2007: 37: 105-113. * The results obtained in the analysis of the thermal behaviour of a forest biomass fluidised bed dryer with mechanical agitation, are reported. The study is carried out in pilot size experimental equipment in batch operation.
75. Reyes A, Diaz G and Marquardt F-H. Analysis of mechanically agitated fluid-particle contact dryers. Drying Technology 2001: 19: 2235-2259. * The physical phenomena occurring in fluidised bed dryer with several liquid substrates was analysed and the residence time distributions were obtained by the use of dye tracers.
76. Huang L and Mujumdar AS. Spray drying technology - Principles and Practice'. In: Guide to Industrial Drying: Principles, Equipment and New developments. Edited by A.S. Mujumdar (Editor). 2004. Colour Publications Pvt. Ltd., Mumbai, India, pp.143-173. * The authors gave a classification and selection criteria of different spray dryers based on required product specifications. Design considerations and the computational fluid dynamics simulations are also reported for vertical spray drying systems. The schematics of novel one-stage and two-stage horizontal spray dryers are given.
77. Kwamya M. Eng. Thesis, Department of Chemical Engineering. 1984. McGill University, Montreal, Canada. (Advisor: Prof. AS Mujumdar) * This thesis developed the first simple mathematical model to evaluate horizontal spray dryer.
78. C.E. Rogers Company, USA, http://www.cerogers.com/html/horizontal_dryer. html
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80. S.S. Techno Services Pvt. Ltd., India, http://sstechno.com
81. Cakaloz T, Akbaba H, Yesugey ET and Periz A. Drying model for a-amylase in a horizontal spray dryer. Journal of Food Engineering 1997: 31: 499-510. ** A model for a horizontal spray dryer for the drying of a-amylase is presented.
82. Huang L and Mujumdar AS. Development of a new innovative conceptual design for horizontal spray dryer via mathematical modeling. Drying Technology 2005: 23: 1169-1187. ** This article presents an illustration of horizontal spray drying process to arrive at a new conceptual design for the traditional spray-drying process. Several stages in the evolution of the horizontal spray dryer design concept are presented and discussed. This article presents simulation results for several spray chamber designs and points out the importance of the design of the air inlet and outlet arrangement for optimal efficiency and effectiveness.
83. Huang L and Mujumdar AS. Numerical study of two-stage horizontal spray dryers using computational fluid dynamics. Drying Technology 2006: 24: 727-733. ** This article presents the findings of a numerical simulation model of the spray-drying process in a two-stage horizontal chamber design with the aid of a computational fluid dynamic model. In this study, a new two-dimensional horizontal spray dryer geometry is considered as a pilot study into the spray-drying process.
84. Van Drooge DJ, Hinrichs WLJ, Visser MR and Frijlink HW. Characterization of the molecular distribution of drugs in glassy solid dispersions at the nano-meter scale, using differential scanning calorimetry and gravimetric water vapour sorption techniques. International Journal of Pharmaceutics 2006: 310: 220-229. ** The molecular distribution in fully amorphous solid dispersions consisting of poly(vinylpyrrolidone) (PVP)-diazepam and inulin-diazepam was studied. The solid dispersions were prepared by freeze drying and SFD.
85. Elia AM and Barresi AA. Intensification of transfer fluxes and control of product properties in freeze-drying. Chemical Engineering and Processing 1998: 37: 347-358.
86. Broadhead J, Edmond-Rouan SK and Rhodes CT. The spray-drying of pharmaceuticals. Drug Development and Industrial Pharmacy. 1996: 22: 813-822.
87. Burke PA, Klumb LA, Herberger JD, Nguyen XC, Harrell RA and Zordich M. Poly(Lactide-Co-Glycolide) microsphere formulations of Darbepoetin Alfa: spray drying is an alternative to encapsulation by spray-freeze drying. Pharmaceutical Research 2004: 21: 500-506. ** The purpose of this work was to evaluate SFD and spray drying processes for encapsulation of darbepoetin alfa. Darbepoetin alfa was encapsulated in poly(lactide-co-glycolide) by SFD and by spray drying.
88. Nguyen XC, Herberger JD and Burke1 PA. Protein powders for encapsulation: a comparison of spray-freeze drying and spray drying of Darbepoetin Alfa. Pharmaceutical Research 2004: 21: 507-514. ** The author's evaluated SFD and spray drying processes for fabricating micron-sized particles of darbepoetin alfa with uniform size distribution and retention of protein integrity. Darbepoetin alfa was spray-freeze dried using ultrasonic atomisation and spray dried at bench-top and pilot scales.
89. Winters MA, Knutson BL, Debenedetti PG, Sparks G, Przybycien TM, Stevenson CL and Prestrelski SJ. Precipitation of proteins in supercritical carbon dioxide. Journal of Pharmaceutical Sciences 1996: 85: 586-594.
90. Bałdyga J and Henczka M. Particle elaboration using supercritical media for drug delivery into the human lungs. In: Optimization of Aerosol Drug Delivery. Edited by Marijnissen, J.C.M. and Gradón, L. (Editors). 2003.
91. Henczka M, Bałdyga J and Shekunov BY. Modelling of spray-freezing with compressed carbon dioxide. Chemical Engineering Science 2006L: 61: 2880-2887.
92. Maa YF, Nguyen PA, Sweeney T, Shire SJ and Hsu CC. Protein inhalation powders: spray drying vs spray freeze drying. Pharmaceutical Research 1999: 16: 249-254. ** A new technique, SFD, for preparing protein aerosol powders is developed. Comparison of spray freeze-dried powders with spray-dried powders is made in terms of physical properties and aerosol performance.
93. Shekunov B, Chattopadhyay P, Seitzinger J, Bałdyga J and Henczka M. Optimization of spray-freezing for production of respirable particles. The AAPS Journal. 2004: 6: Abstract M1145.
94. Chow AHL, Tong HHY, Chattopadhyay P and Shekunov BY. Particle engineering for pulmonary drug delivery. Pharmaceutical Research 2007: 24: 411-437. ** A critical account of the current goals and technologies of particle engineering for the development of pulmonary drug delivery systems is provided. These technologies cover traditional micronisation and powder blending, controlled solvent crystallisation, spray drying, SFD, particle formation from liquid dispersion systems, supercritical fluid processing and particle coating. The merits and limitations of these technologies are discussed with reference to their applications to specific drug and/or excipient materials. The regulatory requirements applicable to particulate inhalation products are also reviewed briefly.
95. Abdul-Fattah AM, Kalonia DS and Pikal MJ. The challenge of drying method selection for protein pharmaceuticals: product quality implications. Journal of Pharmaceutical Sciences 2007: 96: 1886-1916. ** The authors reviewed and compared some important physico-chemical properties of the dried powder that result from using different drying methods such as specific surface area, molecular dynamics, secondary structure (for protein molecules), and composition heterogeneity. They also briefly introduced and compared the unit operations involved in the drying methods to give an insight on thermal history, and the different stresses that a drying method can present to an active ingredient, particularly for protein molecules.
96. Anandharamakrishnan C, Khwanpruk K, Rielly C and Stapley A. Spray-freeze-drying at sub-atmospheric pressures. Proceedings of the IDS'06 2006: 636-642.
97. 9- tetrahydrocannabinol (THC) is stabilised. Solutions of THC and inulin in a mixture of tertiary butanol (TBA) and water were spray freeze dried. Stability of THC was determined and compared with freeze dried material.
98. Yu Z, Johnston KP and Williams III RO. Spray freezing into liquid versus spray-freeze drying: Influence of atomization on protein aggregation and biological activity. European Journal of Pharmaceutical Sciences 2006: 27: 9-18. ** Protein aggregation and enzyme activity were compared for reconstituted lysozyme particles produced by two cryogenic technologies, spray freezing into liquid and SFD.
99. Yokota T, Takahata Y, Katsuyama T and Matsuda Y. A new technique for preparing ceramics for catalyst support exhibiting high porosity and high heat resistance. Catalysis Today 2001: 69: 11-15.
100. Cleland JL, Johnson OL, Putney S and Jones AJS. Recombinant human growth hormone poly(lactic-co-glycolic acid) microsphere formulation development', Advanced Drug Delivery Reviews 1997: 28: 71-84.
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103. Sonner C. Protein-loaded powders by spray freeze drying. PhD thesis. 2002. Department of Pharmaceutics, Friedrich-Alexander University, Erlangen, Germany.
104. Sweeney LG, Wang Z, Loebenberg R, Wong JP, Lange CF and Finlay WH. Spray-freeze-dried liposomal ciprofloxacin powder for inhaled aerosol drug delivery. International Journal of Pharmaceutics 2005: 305: 180-185. ** SFD was utilised to manufacture a liposomal powder formulation containing ciprofloxacin as a model active component. Aerosol properties of this formulation were assessed using a new passive inhaler, in which the powder was entrained.
105. Weers JG, Tarara TE and Clark AR. Design of fine particles for pulmonary drug delivery. Expert Opinion on Drug Delivery 2007: 4: 1-17.
106. Mumenthaler M and Leuenberger H. Atmospheric spray-freeze drying: a suitable alternative in freeze-drying technology. International Journal of Pharmaceutics 1991: 72: 97-110. * As an alternative to the classical freeze-drying process in a vacuum, the feasibility of dehydrating frozen pharmaceutical solutions and liquid foods at atmospheric pressure was investigated. An apparatus and a technique for sprayfreezing aqueous solutions in situ at very low temperatures and for subsequent dehydration of the resulting frozen particles in a stream of cold, desiccated air was developed.
107. Leuenberger H. Spray-freeze-drying - the process of choice for low water soluble drugs?. Journal of Nanoparticle Research 2002: 4: 111-119. ** The use of the vacuum-fluidised-bed technique for the spray-drying of a low water soluble drug cosolubilised with a hydrophilic excipient in a polar organic solvent is discussed. In order to avoid the use of organic solvents, a special spray-freeze-drying technique working at atmospheric pressure is presented.
108. Leuenberger H, Plitzko M and Puchkov M. Spray freeze drying in a fluidized bed at normal and low pressure. Drying Technology 2006: 24: 711-719. ** The aim of this study was to develop the SFD process and its hardware and to investigate its capabilities to dry thermosensitive substances such as pharmaproteins at normal and low pressures. As a result, a spray freeze fluidised-bed dryer was constructed.
109. Wang ZL, Finlay WH, Peppler MS and Sweeney LG. Powder formation by atmospheric spray-freeze drying. Powder Technology 2006: 170: 15-52. * Compared with other published atmospheric spray-freeze-drying technologies, the new technology combines the spray-freezing step and fluidisation conveying of frozen powder using co-current flow to convey the frozen powder to the exit filter. This overcomes the difficulty of fluidising and elutriating cohesive frozen powder from a substrate.
110. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC Press; 2007 pp.879-885.
111. Waje SS, Thorat BN and Mujumdar AS. An experimental study of the thermal performance of a screw conveyor dryer. Drying Technology. 2006: 24: 293-301. ** Drying of fine crystalline solid was carried out in a non-insulated jacketed screw conveyor dryer. Dryer performance was evaluated in terms of the final moisture content, heat-transfer coefficient, thermal efficiency and power consumption.
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113. th Edition. Edited by Kroschwitz, J.I. (Editor). New York: John Wiley & Sons; 1993: pp.475-519.
114. th Edition. Edited by W. Gerhartz (Editor). Germany: VCH Publishers; 1988 Vol. B2.
115. Waje SS, Thorat BN and Mujumdar AS. Screw conveyor dryer: Process and Equipment design. Drying Technology 2007: 25: 241-247. ** The effects of various process variables and equipment components (geometry) on the performance of a screw conveyor dryer were studied in terms of the material throughput and its uniformity, dryer load, specific consumption of mechanical energy, and heat transfer rate.
116. Toel R, Ohmori T, Furuta T and Okazaki M. Heat transfer in an indirectheat agitated dryer. Chemical Engineering and Processing 1984: 18: 149-155.
117. Kim H, Shin M, Jang D and Na E. A Study for the thermal treatment of dehydrated sewage sludge with gas-agitated double screw type dryer. Journal of Environmental Science and Health, Part A. 2005: 40: 203-213. * A specially designed dryer has been developed for the thermal treatment of dehydrated, highly viscous sewage sludge with moisture content more than 80 wt.% by an gas-agitated, double-screw type dryer system. The treatment capacity of sludge dryer was about 100 kg/h.
118. th Edition. Edited by Perry, R.H.; Chilton, C.H., (Editors). Tokyo: McGraw-Hill, Inc.; Section 11, 1973 pp.42-48.
119. Tsai W and Lin C. On the mixing of granular materials in a screw feeder. Powder Technology 1994: 80: 119-126.
120. Waje SS, Patel AK, Thorat BN and Mujumdar AS. Study of residence time distribution in a pilot scale screw conveyor dryer. Drying Technology 2007: 25: 249-259. ** The effects of feed rate and screw speed on the residence time distribution were studied for the conveying of sand in a pilot-scale screw conveyor dryer using pulse input of a tracer. Two new parameters defining the relative stagnancy and screw effectiveness were introduced to study the flow performance of screw conveyor dryer.
121. Waje SS, Thorat BN and Mujumdar AS. Hydrodynamic characteristics of a pilot scale screw conveyor dryer. Drying Technology 2007: 25: 609-616. ** The effects of granular solids flow rate and screw speed on the residence time distribution were studied using sand as the model material. The residence time distribution was measured using a dynamic step change in the solids flow rate. Parameters such as solids holdup, degree of fullness, mean residence time, and uniformity of the discharge flow were studied.
122. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC Press; 2007 pp.1019-1040.
123. Roberts AW. The influence of granular vortex motion on the volumetric performance of enclosed screw conveyors. Powder Technology 1999: 104: 56-67.
124. Shu-de Q, Fang-Zhen G and Dong-li Z. The Study on Performance of Twin Screw Conveyor. Drying Technology 1996: 14: 1859-1870.
125. Benali M and Kudra T. Thermal Dewatering of Diluted Organic Suspensions: Process Mechanism and Drying Kinetics. Drying Technology 2002: 20: 935-951. ** Drying of raw hog manure, a highly diluted suspension of organic and inorganic matter was studied experimentally in the multistage screw-in-trough dryer. Laboratory tests included material characteristics, boiling pattern, and kinetics of convective drying.
126. Al-Kassir A, Ganan J and Tinaut FV. Theoretical and experimental study of a direct contact thermal screw dryer for biomass residues. Applied Thermal Engineering 2005: 25: 2816-2826. ** A one-dimensional model has been developed for the calculation and design of a direct contact thermal screw dryer for biomass residues. An experimental facility has been developed in order to measure the temperature inside the dryer along time.
127. Sabarez HT and Noomhorm A. Performance testing of an experimental screw conveyor dryer for roasting cashew nuts. Postharvest Biology and Technology 1993: 2: 171-178. * An experimental screw conveyor dryer using rice husk-fired furnace as heat source was developed for safe roasting of cashew nuts. The performance of the system was evaluated in terms of the kernel quality. The effect of varying the operating conditions was investigated to determine the optimum operating conditions of the unit and these were compared with hot-oil bath method.
128. Noomhorm A, Premakumar K and Sabarez HT. Design and Development of a Conduction Drier for Accelerated Drying of Peanuts. Journal of Food Engineering 1994: 21: 411-419. * A rotary conduction drier using sand as the heating medium was designed and developed for accelerated drying of high moisture peanuts. The performance characteristics of the drier were evaluated in terms of peanut quality and drying time.
129. Erle U. Drying using microwave processing. In: The Microwave Processing of Foods. Edited by Schubert H. and Regier, M. (Editors). New York; CRC press; 2005 pp.142-152. ** Applications of microwave in various industrial applications have been mentioned along with its impact on product quality and drying kinetics as compared with conventional drying techniques.
130. Zhang M, Tang J, Mujumdar AS and Wang S. Trends in microwave-related drying of fruits and vegetable. Trends in Food Science and Technology 2006: 17: 524-534. ** This paper presents a comprehensive review of recent progresses in MW-related combined drying research and recommendations for future research to bridge the gap between laboratory research and industrial applications.
131. Kelen A, Ress S, Nagy T, Pallai E and Pintye-Hodi K. Mapping of temperature distribution in pharmaceutical microwave vacuum drying. Powder Technology 2006: 162: 133-137.
132. rd Edition. Edited by A.S. Mujumdar (Editor). New York: CRC press; 2007 pp. 285-305. ** This book reviewed various industrial applications, advantages, limitations and the working principles of microwave and dielectric heating and drying.
133. Gunasekaran S. Pulsed microwave-vacuum drying of food materials. Drying Technology 1999: 17: 395-412.
134. Puschner P. Improved microwave process control. In: The Microwave Processing of Foods. Edited by Schubert H. and Regier, M. (Editors). New York: CRC press; 2005 pp.264-291.
135. Stanisławski J. Drying of diced carrot in a combined microwave-fluidized bed dryer. Drying Technology 2005: 23: 1711-1721. ** Drying of diced carrot was carried out in a laboratory microwave fluidisedbed dryer and in a standard fluidised-bed dryer. The performance of both the processes was compared in terms of drying efficiency.
136. Goksu EI, Sumnu G and Esin A. Effect of microwave on fluidized bed drying of macaroni beads. Journal of Food Engineering 2005: 66: 463-468.
137. Wang W, Thorat BN, Chen G and Mujumdar AS. Simulation of fluidized-bed drying of carrot with microwave heating. Drying Technology 2002: 20: 1855-1867. * A mathematical model of coupled heat and mass transfer was applied to batch fluidised-bed drying with microwave heating of a heat sensitive material-carrot. Four kinds of microwave heating with intermittent variation were examined.
138. Jumah RY and Raghavan GSV. Analysis of heat and mass transfer during combined microwave-convective spouted-bed drying. Drying Technology 2001: 19: 485-506.
139. Feng H, Tang J, Cavalieri RP and Plumb OA. Heat and mass transport in microwave drying of porous materials in a spouted bed. AIChE Journal 2001: 47: 1499-1512.
140. Ben Souda K, Akyel C and Bilgen E. Freeze dehydration of milk using microwave energy. Journal of Microwave Power and Electromagnetic Energy 1989: 24: 195-202.
141. Wang W and Chen G. Heat and mass transfer model of dielectricmaterial- assisted microwave freeze drying of skim milk with hygroscopic effect. Chemical Engineering Science 2005: 60: 6542-6550.
142. Wang W and Chen G. Theoretical study on microwave freeze drying of an aqueous pharmaceutical excipient with the aid of dielectric material. Drying Technology 2005: 23: 2147-2168.
143. Wang W and Chen G. Numerical investigation on dielectric material assisted microwave freeze drying of aqueous mannitol solution. Drying Technology 2003: 21: 995-1017.
144. Wang W, Chen G and Gao F. Effect of dielectric material on microwave freeze drying of skim milk. Drying Technology 2005: 23: 317-340. * A simultaneous heat and mass transfer model of the dielectric material-assisted microwave freeze drying was derived in this study considering the vapour sublimation-desublimation in the frozen region.
145. Wang ZH and Shi MH. Microwave freeze drying characteristics of beef. Drying Technology 1999: 17: 433-447. * Microwave freeze drying characteristics of unsaturated raw beef were studied experimentally for various levels of electric field strength, vacuum pressure, sample thickness and initial saturation.
146. Duan X, Zhang M and Mujumdar AS. Studies on the microwave freeze drying technique and sterilization characteristics of cabbage. Drying Technology 2007: 25: 1725-1731.
147. Yonsawatdigul J and Gunasekaran S. Microwave-vacuum drying of cranberries: Part II. Quality evaluation. Journal of Food Processing and Preservation 1996: 20: 145-156.
148. Qing-Guo H, Min Z, Mujumdar AS, Wei-Hua D and Jin-Cai S. Effects of different drying methods on the quality changes of granular edamame. Drying Technology 2006: 24: 1025-1032.
149. Cui ZW, Sun LJ, Chen W and Sun DW. Preparation of dry honey by microwave-vacuum drying. Journal of Food Engineering 2008: 84: 582-590.
150. Sundaram J and Durance TD. Influence of processing methods on mechanical and structural characteristics of vacuum microwave dried biopolymer foams. Food and Bioproducts Processing 2007: 85: 264-272. * Different types of dried cellular biopolymer foams were produced using different food hydrocolloids at various proportions by gel processing methods. Drying was carried out using vacuum microwave dryer.
151. Giri SK and Prasad S. Modeling shrinkage and density changes during microwave-vacuum drying of button mushroom. International Journal of Food Properties 2006: 9: 409-419.
152. Giri SK and Prasad S. Drying kinetics and rehydration characteristics of microwave-vacuum and convective hot-air dried mushrooms. Journal of Food Engineering 2007: 78: 512-521. ** Microwave-vacuum dehydration characteristics of button mushroom were evaluated in a commercially available microwave oven modified to a drying system by incorporating a vacuum chamber in the cavity. The effect of drying parameters, namely microwave power, system pressure and product thickness on the drying kinetics and rehydration characteristics were investigated.
153. Giri SK and Prasad S. Optimization of microwave-vacuum drying of button mushrooms using response-surface methodology. Drying Technology 2007: 25: 901-911.
154. Khraisheh MAM, McMinn WAM and Magee TRA. Quality and structural changes in starchy foods during microwave and convective drying. Food Research International 2004: 37: 497-503.
155. Raghavan GSV, Rennie TJ, Sunjka PS, Orsat V, Phaphuangwittayakul W and Terdtoon P. Overview of new techniques for drying biological materials with emphasis on energy aspects. Brazilian Journal of Chemical Engineering 2005: 22: 195-201.
156. Orsat V, Yang W, Changrue V and Raghavan GSV. Microwave-assisted drying of biomaterials. Food and Bioproducts Processing 2007: 85: 255-263. **A review of recent microwave assisted drying applications is presented here along with research results on drying of carrots under varying microwave power modes and the comparative drying of mushrooms by microwave/ convection and microwave/vacuum.
157. Sutar PP and Prasad S. Modeling microwave vacuum drying kinetics and moisture diffusivity of carrot slices. Drying Technology 2007: 25: 1695-1702.
158. Setiady D, Clary C, Younce F and Rasco BA. Optimizing drying conditions for microwave-vacuum (MIVAC® ) drying of russet potatoes (Solanum tuberosum). Drying Technology 2007: 25: 1479-1485.
159. Li Y, Xu SY and Sun DW. Preparation of garlic powder with high allicin content by using combined microwave-vacuum and vacuum drying as well as micro-encapsulation. Journal of Food Engineering 2007: 83: 76-83.
160. Böhm V, Kühnert S, Rohm H and Scholze G. Improving the nutritional quality of microwave-vacuum dried strawberries: A preliminary study. Food Science and Technology International 2006: 12: 67-75.
161. Tsuruta T and Hayashi T. Internal resistance to water mobility in seafood during warm air drying and microwave-vacuum drying. Drying Technology 2007: 25: 1393-1399.
162. Berteli MN, Marsaioli Jr. A and Rodier E. Study of a microwave assisted vacuum drying process applied to the granulated pharmaceutical drug hydrochlorthiazide (HCT). Journal of Microwave Power and Electromagnetic Energy 2007: 40: 241-250. ** The objective of the present work is to study and evaluate the process of drying a granulated product that is the basis of the drug hydrochlorthiazide. This study monitored the drying kinetics, product temperature and power absorbed by the sample using a bench scale vacuum microwave dryer.
163. McMinn WAM, Farrell G and Magee TRA. Prediction of microwave drying behavior of pharmaceutical powders using thin-layer models. Drying Technology 2007: 25: 1547-1565.
164. Farrel G, McMinn WAM. and Magee TRA. Microwave-vacuum drying kinetics of pharmaceutical powders. Drying Technology 2005; 23: 2131-2146.
165. Yaghmaee P and Durance T. Efficacy of vacuum microwave drying in microbial decontamination of dried vegetables. Drying Technology 2007: 25: 1099-1104. * The efficacy of vacuum microwave drying and a combination of microwave processing at atmospheric pressure + vacuum microwave drying on decontamination of freshly grated carrots and parsley leaves from naturally occurring microorganisms was studied.
166. Wolff E and Gilbert H. Atmospheric freeze-drying part 1: Design, Experimental investigation and energy saving advantages. Drying Technology 1990: 8: 385-404. ** This paper describes the experimental study of a new process for freeze-drying based on a fluidised bed of dry absorbent working at atmospheric pressure. Process feasibility has been demonstrated. The kinetics of dehydration has been established systematically for thin-sliced potatoes. A comparison has been carried out with vacuum freeze-drying.
167. Wolff E and Gibert H. Atmospheric freeze-drying part 2: Modelling drying kinetics using adsorption isotherms. Drying Technology 1990: 8: 405-428.
168. Carn RM and King CJ. Modification of conventional freeze dryers to accomplish limited freeze drying. AIChE Symposium Series 1975: 73: 103-112.
169. Goldblith SA, Rey L and Rothmayr WW. Freeze drying and advanced food technology (pp. 345-348). NY: Academic Press.
170. King CJ. Freeze-drying of foodstuffs. CRC Critical Review Food Technology 1975: 1-379.
171. Di Matteo P, Donsi G and Ferrari G. The role of heat and mass transfer phenomena in atmospheric freeze-drying of foods in a fluidised bed. Journal of Food Engineering 2003: 59: 267-275.
172. Ekechukwua OV and Norton B. Review of solar-energy drying systems II: an overview of solar drying technology. Energy Conversion & Management 1999: 40: 615-655. * The paper presents a comprehensive review of the various designs, details of construction and operational principles of the wide variety of solar drying systems. The classification of these dryers was given as well.
173. Othman MYH, Sopian K, Yatim B and Daud WRW. Development of advanced solar assisted drying systems. Renewable Energy 2006: 31: 703-709. * The authors presented four types of solar assisted air heating system, viz. v-groove type solar collector, double-pass solar collector with porous media, photovoltaic thermal solar collector and water based solar collector dehumidification system. The proposed solar assisted air heating systems were attached to a cabinet dryer. It was claimed that the dryer is suitable to dry agricultural product such as chilies, green tea and fruits.
174. Sharma SD, Buddhi D and Sawhney RL. Accelerated thermal cycle test of latent heat-storage materials. Solar Energy 1999: 66: 483-490.
175. Abhat A. Low-temperature latent heat thermal energy storage: heat storage materials, Solar Energy 1983: 30: 313-332.
176. Hawlader MNA, Uddin MS and Khin MM. Microencapsulated PCM thermal-energy storage system. Applied Energy 2003: 74: 195-202. * This paper describes the preparation of and characterisation of encapsulated paraffin wax which is used as latent heat storage agent. Two methods were used in this study, namely coacervation and spray-drying. Microcapsules produced by both methods were found to have a thermal energy storage/release capacity of about 145-240 J/g. The authors claimed that the microcapsule can be used as a latent heat storage agent.
177. Devahastin S and Pitaksuriyarat S. Use of latent heat storage to conserve energy during drying and its effect on drying kinetics of a food product. Applied Thermal Engineering 2006: 26: 1705-1713. * This paper reports the usage of paraffin wax as a latent heat storage agent in a drying system. It was found that the drying rate of sweet potato increased with a decrease of the inlet ambient air velocity. The amount of the energy extracted using this technique was 1,920 and 1,386 kJ min/kg and the energy savings was 40% and 34% at inlet ambient air velocity of 1 and 2 m/s.
178. Enibe SO. Performance of a natural circulation solar air heating system with phase change material energy storage. Renewable Energy 2002: 27: 69-86. * This paper reports the design, construction and performance evaluation of a passive solar powered air heating system that used phase change material as an energy storage agent. The author claimed that the system is suitable for crop drying.
179. Gong ZX. www.simprotech.com for details about new software for flow-sheeting calculations involving dryers and evaporators as well as other ancillary unit operations; 2007.