scholarly journals A comparison of the kinetics of mango drying in open-air, solar, and forced-air dryers

2012 ◽  
Vol 12 (55) ◽  
pp. 6835-6852
Author(s):  
DG Mercer ◽  
Keyword(s):  
Air Temperature ◽  
Operating Conditions ◽  
Wire Mesh ◽  
Solar Drying ◽  
Drying Method ◽  
Air Drying ◽  
Sub Saharan ◽  
Forced Air ◽  
Air Dryer ◽  
Kinetics Of

Mangoes are under-utilized fruits that grow naturally in many sub-Saharan African countries. At the present time most mangoes are sold fresh in local markets. There is little done to preserve them for use during the off-season. Drying is one way in which the economic potential of mangoes could be exploited. This study was undertaken to investigate and compare the kinetics of mango drying using three basic drying methods: open-air drying on wire mesh racks; solar drying in a prototype dryer equipped with solar-powered exhaust fans; and forced-air drying in an Armfield Model UOP8 laboratory-scale tray dryer. Results could then be used to determine appropriate drying techniques for mango processing in sub-Saharan Africa on both local and commercial scales. Of these methods, forced air drying was found to provide the best overall results, based on water removal rates and general control over the drying process. Solar drying, while viewed as a promising technology for application in developing countries, was considerably slower than forced- air drying and is severely restricted by climatic conditions. A similar situation was observed for open-air drying, which was the slowest drying method of the three. Based upon mathematical models developed for each drying method, 11.6 hours was predicted as being required for mangoes in the forced-air dryer to a final moisture content of 10% (wet basis). Sixteen (16) hours and 24 hours of exposure to appropriate drying conditions were predicted as being required for solar drying and open-air drying, respectively. This could take three or four days to achieve under actual operating conditions. These times were supported by experimentally determined values. The impact of air temperature and linear air velocity on the drying kinetics of sliced mangoes were also investigated using the forced-air dryer. A linear velocity of 0.5 m/s was found to be sufficient for satisfactory drying of the mango slices when combined with an air temperature in the range of 50ΕC to 60ΕC. It is recommended that forced-air drying be utilized whenever possible for the drying of mango slices for both food safety and food quality reasons.

Effect of Pre-Treatment on the Drying Characteristics and Kinetics of Okra (Abelmoschus esculetus (L.) Moench) Slices

2009 ◽  
Vol 5 (2) ◽  
Author(s):  
Olajide Sobukola
Keyword(s):  
Air Temperature ◽  
Sample Thickness ◽  
Hot Water ◽  
Drying Rate ◽  
Diffusivity Coefficient ◽  
Drying Characteristics ◽  
Rate Period ◽  
Pretreatment Conditions ◽  
Air Dryer ◽  
Kinetics Of

The effects of air temperature (50, 60 and 70°C), sample thickness (2, 4 and 6mm) and pretreatment conditions (hot water blanching, 1 and 3% sodium metabisulphite solutions) on the drying characteristics and kinetics of okra were investigated using a convective hot air dryer at a flow rate of 1.5m/s. It was observed that pretreatment conditions, sample thickness and drying air temperature significantly (P<0.05) affected drying rate. Drying rate increases as temperature of drying air increases from 50 to 70°C. The drying curve for all experiments occurred in the falling rate period with no constant rate period. Three thin layer drying models (Page, modified Page I and Wang and Singh) were evaluated using coefficient of determination (R2), root mean square error (RMSE) and the reduced chi square (?2). The three models can appropriately describe the drying kinetics of okra slices considering the different experimental conditions. The effective diffusivity was determined using the Fick’s model and was observed to vary between 1.125x10-8 – 9.93x10-9m2/s and 1.165x10-8 – 7.131x10-9 m2/s for treated and untreated samples. The Arrhenius-type relationship describes the temperature dependence of diffusivity coefficient and was determined to be 16.749kJ/mol and 22.437kJ/mol for treated and untreated samples respectively.

scholarly journals Modelado matemático de secado solar de orégano (Plectranthus amboinicus) con tecnologías directas e indirectas

2020 ◽  
pp. 27-36
Author(s):  
Beatriz Castillo-Téllez ◽  
Margarita Castillo-Téllez ◽  
Erick César López-Vidaña ◽  
Gerardo Alberto Mejía-Pérez
Keyword(s):  
Moisture Content ◽  
Temperature Effects ◽  
Initial Moisture Content ◽  
Operating Conditions ◽  
Solar Drying ◽  
Drying Behavior ◽  
Medicinal Properties ◽  
Plectranthus Amboinicus ◽  
Time Required ◽  
Kinetics Of

Oregano is a plant with many nutritional and medicinal properties; there are also other applications in the chemical industry. In this work, the drying kinetics of oregano leaves are studied using a cabinet-type dryer with and without a forced convention, open sun drying, and indirect solar drying. The samples had an initial moisture content of 80 % and the final content of 9 %. The results indicate that indirect solar drying provides better control of operating conditions and greater protection against temperature effects, producing better quality in the dry product. The time required to reach the equilibrium moisture content in all experiments ranged from 375 to 600 min. The data were also adjusted to various mathematical models, resulting In Weibull, Logarithmic, and Page, which best represent the drying behavior of oregano leaves. The statistics used for indirect solar dryer are R2 of 0.9969, 0.9968, and 0.9945, X2 of 0.0363, 0.0363 and 0.0599 respectively.

scholarly journals RESEARCH OF PLUM DRYING PROCESS

2015 ◽  
Vol 3 ◽  
pp. 494-5 ◽  
Author(s):  
Nurlan Kurmanov ◽  
Azret Shingissov ◽  
Gulzhan Kantureyeva ◽  
Zeinep Nurseitova ◽  
Baurzhan Tolysbaev ◽  
...  
Keyword(s):  
Acid Content ◽  
Ascorbic Acid Content ◽  
Drying Method ◽  
Drying Process ◽  
Air Velocity ◽  
Hot Air ◽  
Sensory Parameters ◽  
Air Dryer ◽  
Kinetics Of

In this study, the drying kinetics of a domestic plum cultivar were examined in a laboratory scale hot-air dryer, SHS-80, at an air velocity of 0.65m s-1 and within the air temperature range of 45 – 75 0С. It was found that the whole fruit dried the best. Also, the study  assessed the influence of the drying method on the quality of the domestic plum cultivar. Dried fruits were assessed for sensory parameters and ascorbic acid content. Studies have shown thatthe proposed method of drying, yields a higher absorbic acid content for the dried product  than the conventional approach.

scholarly journals Controlled Release Fertilizer Encapsulated by Glutaraldehyde-Crosslinked Chitosan Using Freeze-Drying Method

2020 ◽  
Vol 20 (6) ◽  
pp. 1414
Author(s):  
Adhitasari Suratman ◽  
Dwi Ratih Purwaningsih ◽  
Eko Sri Kunarti ◽  
Agus Kuncaka
Keyword(s):  
Controlled Release ◽  
Environmental Pollution ◽  
Freeze Drying ◽  
Release Kinetics ◽  
Drying Method ◽  
Air Drying ◽  
Controlled Release Fertilizer ◽  
Npk Fertilizer ◽  
Crosslinked Chitosan ◽  
Kinetics Of

A new encapsulation of NPK fertilizer hydrogel granules made from glutaraldehyde crosslinked chitosan has been successfully fabricated. This designed fertilizer was aimed to maximize the fertilizing process in the soil, as the environmental pollution affected by the excess release of the nutrients can be prevented. The granule was prepared from biodegradable chitosan crosslinked with glutaraldehyde by applying a method of air and freeze-drying. The release test proved that this designed fertilizer showed a good performance as a Controlled Release Fertilizer (CRF) in which the hydrogel granules could absorb and deposit large amounts of NPK. Later on, they could also release large amounts of NPK as well, unlike several types of CRFs. The release percentage of NPK out of the granules tended to decrease with an increase of pH at a range close to the average pH of the soil, which is neutral to base. Comparing two methods, the freeze-drying technique, which yields a bigger pore size, showed a higher release percentage than air-drying. The release kinetics of the granules followed the Korsmeyer-Peppas model.

scholarly journals Drying kinetics of atemoya pulp

2016 ◽  
Vol 20 (7) ◽  
pp. 672-677 ◽  
Author(s):  
Plúvia O. Galdino ◽  
Rossana M. F. de Figueirêdo ◽  
Alexandre J. de M. Queiroz ◽  
Pablícia O. Galdino
Keyword(s):  
Mixing Time ◽  
Theoretical Models ◽  
Coefficient Of Determination ◽  
Drying Method ◽  
Content Ratio ◽  
Different Temperatures ◽  
Forced Air ◽  
Drying Curves ◽  
Kinetics Of ◽  
Best Fit

ABSTRACT This study was conducted in order to obtain drying curves of whole atemoya pulp through the foam-mat drying method. The suspension was prepared with whole atemoya pulp mixed with 2% of Emustab® and 2% of Super Liga Neutra® with mixing time of 20 min, and dried in a forced-air oven at different temperatures (60; 70 and 80 °C) and thicknesses of the foam layer (0.5, 1.0 and 1.5 cm). The drying rate curves were plotted against the water content ratio and the semi-theoretical models of Henderson & Pabis, Page and Midilli were used. All tested models showed coefficient of determination (R2) above 0.993, and the Midilli model showed the best fit for all conditions. Drying curves were affected by temperature and layer thickness.

Forced-air drying of ginseng root: 1. Effects of air temperature on quality

2004 ◽  
Vol 63 (4) ◽  
pp. 361-367 ◽  
Author(s):  
Valerie J. Davidson ◽  
Xiang Li ◽  
Ralph B. Brown
Keyword(s):  
Air Temperature ◽  
Ginseng Root ◽  
Air Drying ◽  
Forced Air

Influence of the spray drying operating conditions on the estimated drying kinetics of emulsion single droplets and the properties of microencapsulated chia oil

2021 ◽  
Vol 383 ◽  
pp. 302-317
Author(s):  
M. Gabriela Bordón ◽  
Noelia P.X. Alasino ◽  
Vanina Martínez ◽  
Regina Gauna Peter ◽  
Ramiro Iturralde ◽  
...  
Keyword(s):  
Spray Drying ◽  
Drying Kinetics ◽  
Operating Conditions ◽  
Single Droplets ◽  
Kinetics Of ◽  
Chia Oil

Effects of Air Temperature on Combustion Characteristics of LPG Diffusion Flame

2020 ◽  
Vol 1008 ◽  
pp. 128-138
Author(s):  
Ahmed M. Salman ◽  
Ibrahim A. Ibrahim ◽  
Hamada M. Gad ◽  
Tharwat M. Farag
Keyword(s):  
Air Temperature ◽  
Diffusion Flame ◽  
Nitrogen Addition ◽  
Flame Length ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Low Oxygen ◽  
Air Temperatures ◽  
Air Stream ◽  
Wide Range

In the present study, the combustion characteristics of LPG gaseous fuel diffusion flame at elevated air temperatures were experimentally investigated. An experimental test rig was manufactured to examine a wide range of operating conditions. The investigated parameters are the air temperatures of 300, 350, 400, 450, and 500 K with constant percentage of nitrogen addition in combustion air stream of 5 % to give low oxygen concentration of 18.3 % by mass at constant air swirl number, air to fuel mass ratio, and thermal load of 1.5, 30, and 23 kW, respectively. The gaseous combustion characteristics were represented as axial and radial temperatures distributions, temperatures gradient, visible flame length and species concentrations. The results indicated that as the air temperature increased, the chemical reaction rate increased and flame volume decreased, the combustion time reduced leading to a reduction in flame length. The NO concentration reaches its maximum values near the location of the maximum centerline axial temperature. Increasing the combustion air temperature by 200 K, the NO consequently O2 concentrations are increased by about % 355 and 20 % respectively, while CO2 and CO concentrations are decreased by about % 21 and 99 % respectively, at the combustor end.

Sign in / Sign up

Export Citation Format

Share Document