Cooling and Freezing of Cashew Apple Using Computational Fluid Dynamics: The Effect of the Moisture Content

2020 ◽  
Vol 399 ◽  
pp. 190-195
Author(s):  
Vanderson Alves Agra Brandão ◽  
Robson Araújo de Queiroz ◽  
Hallyson Gustavo Guedes de Morais Lima ◽  
Raimundo Pereira de Farias ◽  
Ana Raquel Carmo de Lima ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Moisture Content ◽  
Nutritional Value ◽  
Fruits And Vegetables ◽  
Initial Moisture Content ◽  
Freezing Process ◽  
Cooling Period ◽  
Cashew Apple ◽  
Freezing Period ◽  
Kinetics Of

Cashew is a fruit with high nutritional value and great economic importance in the Northeast region of Brazil, however, due to high moisture content, it is highly perishable. Freezing is one the most efficient methods for conservationof biological products, especially, fruits and vegetables. Then, the optimizationof the freezing process by numerical simulation is crucial. In this sense, the objective of this work was to investigate the influence of the moisture content on the cooling and freezing processes of cashew appleby using thecomputational fluid dynamics technique. Results of the cooling and freezing kinetics of the cashew apple and temperature distribution inside the fruitduring these processes are presented and analyzed. It was verified that the variation inthe initial moisture content had small effect in the total time of the process, however the samples with higher moisture content presented higher heat transfer rate during the cooling period and lesser during the freezing period.

Cooling and Freezing of Cashew Apple Using Computational Fluid Dynamics

2020 ◽  
Vol 25 ◽  
pp. 114-132 ◽  
Author(s):  
V.A. Agra Brandão ◽  
R. Araújo de Queiroz ◽  
R. Lima Dantas ◽  
G. Santos de Lima ◽  
N. Lima Tresena ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nutritional Value ◽  
Fruits And Vegetables ◽  
Numerical Study ◽  
Freezing Process ◽  
Ansys Cfx ◽  
Cashew Apple ◽  
Freezing Period ◽  
Kinetics Of

Freezing is one the most efficient methods for conservation, especially, fruits and vegetables. Cashew is a fruit with high nutritional value and great economic importance in the Northeast region of Brazil, however, due to high moisture content, it is highly perishable. The numerical study of the freezing process is of great importance for the optimization of the process. In this sense, the objective of this work was to study the cooling and freezing processes of cashew apple using computational fluid dynamics technique. Experiments of cooling and freezing of the fruit, with the aid of a refrigerator,data acquisition system and thermocouples, and simulation using Ansys CFX® software for obtain the cooling and freezing kinetics of the product were realized. Results of the cooling and freezing kinetics of the cashew apple and temperature distribution inside the cashew apple are presented, compared and analyzed. The model was able to predict temperaturetransient behavior with good accuracy, except in the post-freezing period.

scholarly journals Experimental Study on the Effect of Freezing and Thawing on the Shear Strength of the Frozen Soil in Qinghai-Tibet Railway Embankment

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
B. Wang ◽  
J. H. Gao ◽  
Y. Q. Wang ◽  
X. J. Quan ◽  
Y. W. Gong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Internal Friction ◽  
Moisture Content ◽  
Initial Moisture Content ◽  
Friction Angle ◽  
Frozen Soil ◽  
Internal Friction Angle ◽  
Freezing Process ◽  
Dry Density ◽  
Freezing And Thawing

The direct shear tests of different dry density and moisture content samples at different temperatures of the frozen soil in the Qinghai-Tibet Railway embankment between Tanggula South and Anduo section were carried out to analyze the influence rules of each experimental factor on the mechanical properties of frozen soil during the freeze-thaw process. The results show the following. (1) When the frozen soil temperature is below 0°C and continues to drop during the freezing and thawing process, each sample shows the law of a significant increase in cohesion and a slight decrease in the internal friction angle. In the meantime, the cohesion obtained during the thawing process of the sample at the same temperature point is higher than that obtained during the freezing process. In contrast, the internal friction angles exhibit an opposite law, where the internal friction angle during the melting process is lower than the internal friction angle during the freezing process. After freezing-thawing action, it deserves to be mentioned that the cohesion increases slightly while the internal friction angles present a slight decrease trend compared to the initial state. (2) With the decrease in temperature and the gradual increase in cohesion, the temperature curve can be divided into a fast-growing section from 0 to −2°C, a slow-growing section from −2 to −8°C, and a second fast-growing section from −8 to −10°C owing to the combined effect of the pressure-thawing action and ice-water phase change. In addition, the rate of decrease in the internal friction angle also shows a similar pattern. (3) The cohesion and the internal friction angle of samples both tend to increase first and then decrease with the rise of the initial moisture content, and the critical initial moisture content is near the optimal moisture content of 15%. (4) Both the cohesion and the internal friction angle of the samples increase with dry density growth. The growth rate of cohesion will gradually increase as the temperature decreases. Moreover, the growth rate of cohesion of low dry density samples is more susceptible to temperature, while the internal friction angle growth rate is not affected by temperature.

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.

Diffusion of Water in Chestnut Fruits during Drying and Rehydration Processes at Different Temperatures

2008 ◽  
Vol 273-276 ◽  
pp. 758-763
Author(s):  
Ramón Moreira ◽  
Francisco Chenlo ◽  
L. Chaguri ◽  
Christiana Fernandes
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Convective Drying ◽  
Transfer Processes ◽  
Hot Air ◽  
Mass Transfer Processes ◽  
Different Temperatures ◽  
Diffusional Model ◽  
Kinetics Of

Many food materials must be dried in order to decrease its water activity and to increase the shelf-life. Also, rehydration operation must be carried out as previous step before consumption. Both operations are commonly employed in some industrial chestnut processing. These processes can be carried out at different temperatures and in all cases the quality of the final product can be affected. In this work, convective drying with hot air is the employed method for water removal and rehydration is carried out by immersion of chestnut in water. In both cases, mass transfer processes are governed by water diffusion in the bulk of the solid. The aim of this work is to determine experimentally the drying and rehydration kinetics of chestnut samples at different conditions of temperature and moisture content. Obtained data are modeled with a diffusional model taking into account volume variations and the corresponding values of the coefficients of diffusion of water are obtained. Analysis of the results indicates that drying/rehydration rates increase with temperature and rehydration kinetics are also depending on the initial moisture content of chestnut. Finally, leaching flow during rehydration is only important at high temperature due to starch gelatinization processes.

Kinetics of forced convective air drying of potato and squash slabs / Cinética del secado de rodajas de patatas y calabacin con corriente de aire

1997 ◽  
Vol 3 (4) ◽  
pp. 251-261 ◽  
Author(s):  
C.O. Rovedo ◽  
C. Suárez ◽  
P.E. Viollaz
Keyword(s):  
Moisture Content ◽  
Surface Area ◽  
Initial Moisture Content ◽  
Three Dimensional ◽  
Sorp Tion ◽  
Air Drying ◽  
Solid Diffusion ◽  
Drying Behaviour ◽  
Drying Curves ◽  
Kinetics Of

Moisture content, temperature, and surface area variations of potato and squash slabs were measured during forced convective air drying; the effect of the initial moisture content on drying behaviour was also investigated. A mathematical model that numerically integrated the diffusion equation and the thermal balance for a three-dimensional shrinking slab was used to simulate the drying process. The parameters of the model (surface area, heat transfer coefficient and dry solid density) were experimentally determined. Fitting parameters (activation energy and pre- exponential coefficient in the Arrhenius equation) were found by comparing experimental and predicted drying curves. Good agreement was obtained down to a moisture level of 0.4 kg water/kg dry solid. Diffusion coefficients were independent of their moisture content within the range studied for both products. The activation energies for potato and squash were 2.09 x 104 kJ/kg mol and 3.76 x 10 4 kJ/kg mol, respectively. Changes in the rates of drying and heating curves for potato took place at moisture levels around 0.4 kg water/kg dry solid, but this was not the case for squash. The differences were mainly attributed to the different shapes of the sorp tion isotherms.

scholarly journals Kinetics of water sorption of damaged bean grains: Thermodynamic properties

2017 ◽  
Vol 21 (8) ◽  
pp. 556-561 ◽  
Author(s):  
Paulo C. Corrêa ◽  
Fernanda M. Baptestini ◽  
Jaime D. B. Vanegas ◽  
Rafael Leite ◽  
Fernando M. Botelho ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Moisture Content ◽  
Adsorption Process ◽  
Initial Moisture Content ◽  
Mechanical Damage ◽  
Climatic Chamber ◽  
Desorption Process ◽  
Adsorption Sites ◽  
Differential Enthalpy ◽  
Kinetics Of

ABSTRACT This study aims to determine the thermodynamic properties of damaged beans. Grains with initial moisture content of 53.85% (d.b.) were used. A part of the grains was used to obtain the desorption isotherms, while another part was subjected to drying until a moisture content of 5.26% (d.b.) was achieved; therefore, it was subjected to the adsorption process. To induce damage, a Stein breakage tester was used. To obtain the equilibrium moisture content, grains were placed in a climatic chamber whose temperatures were 20, 30, 40, and 50 ± 1 °C combined with a relative humidity of 30, 40, 50, 70, and 90 ± 3%. Although in the desorption process, damaged grains had a lower differential enthalpy compared with the control, the reverse behavior was observed in the adsorption process. Mechanical damage caused the formation of a greater number of available adsorption sites, resulting in higher differential entropy values in adsorption and lower values in desorption compared with the control. The mechanical damage had no effect on the Gibbs free energy.

Isotherm Adsorption Behavior and Drying Kinetics of Black Pepper

2012 ◽  
Vol 622-623 ◽  
pp. 1580-1585
Author(s):  
A. Sae-Khow ◽  
S. Tirawanichakul ◽  
Y. Tirawanichakul
Keyword(s):  
Energy Consumption ◽  
Relative Humidity ◽  
Moisture Content ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Initial Moisture Content ◽  
Black Pepper ◽  
Drying Kinetics ◽  
Drying Temperature ◽  
Kinetics Of

The objective of this research were to evaulate equilibrium moisture contents (EMC) of black pepper using the gravimetric-static method and to study the drying kinetics of pepper using 1-stage hot air (HA) drying, 1-stage infrared (IR) drying, 2-stages drying with microwave (MW) and IR and 2-stages drying with MW and HA including to the specific energy consumption determination. For the first objective, the five saturated salt solutions were used for providing equlibrate state between pepper and surrounding at temperature ranging of 40-65°C correlated to relative humidity ranging of 10-90%. The results showed that EMC value decreased with increasing temperature at constant relative humidity. To evaluate the EMC value, the experimental data was simulated by four conventional EMC models and the criteria of the best fiiting models were determined by the determination of coefficient (R2) and the root mean square error (RMSE) value. The results showed that the calculated value using the Modified Oswin model was the most suitable for describing the relationship among equilibrium moisture content, relative humidity and temperature. To study effect of drying condition on drying kinetics, the initial moisture content and final moisture content after drying of papper sample was in ranges of 300-400% dry-basis and 12-16% dry-basis, respectively. The experimetal data were simulsted using empirical drying models and the results showed that the drying temperature relatively affected to drying rate of pepper while the evolution of moisture transfer was in the drying falling ratefor all drying strategies. The 1-stage IR drying and 2-stages drying with MW and IR provided low specific energy consumption (SEC) (0.11-0.15 MJ/kg of water evaporated) compared to the other drying strategies (0.87-1.52 MJ/kg of water evaporated). Moreover, the SEC of pepper drying decreased with increasing of drying temperature.

scholarly journals Experimental Study on Moisture Migration of Unsaturated Loess during the Freezing Process

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hui Zhang ◽  
Tiehang Wang ◽  
Enlong Liu ◽  
Mengling Hu
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Freezing Process ◽  
Dry Density ◽  
Freezing Front ◽  
Slow Cooling ◽  
Moisture Migration ◽  
Cooling Stage ◽  
Large Size ◽  
Unsaturated Loess

To reveal the water-heat transfer mechanism of unsaturated loess, the effects of soil dry density (1.30 g/cm3, 1.50 g/cm3, and 1.65 g/cm3), moisture content (13.3%, 16.2%, and 19.4%), cold end temperature (−7°C, −10°C, and −13°C), and freezing mode on moisture migration in unsaturated loess in this paper are studied through indoor tests of moisture migration under the freezing action of large-size unsaturated loess. The results show that the temperature change in soil samples in the freezing process can be divided into three stages: rapid cooling stage, slow cooling stage, and stable stage. The higher the dry density, the closer the freezing front is to the cold end, with the initial moisture content having little effect on the freezing front, while the temperature at the cold end has a significant effect on the location of the freezing front. The total amount of moisture migration decreases with the increase of dry density, increases with the increase of moisture content, and increases with the decrease of cold end temperature. The freezing mode directly affects the distribution of moisture content and total amount of moisture migration in the frozen area.

Model of Phanerochaete chrysosporium Growth and Multisubstrate Degradation on the Biological Pretreatment of Water Hyacinth

2015 ◽  
Vol 1101 ◽  
pp. 280-285
Author(s):  
Eka Sari ◽  
Siti Syamsiah ◽  
Hary Sulistyo ◽  
Muslikhin Hidayat
Keyword(s):  
Moisture Content ◽  
Phanerochaete Chrysosporium ◽  
Water Hyacinth ◽  
Initial Moisture Content ◽  
Fungal Growth ◽  
Dry Weight ◽  
Batch Process ◽  
Oxygen Conditions ◽  
Kinetics Of ◽  
Limited Oxygen

A mathematical model was developed to predict the kinetics of Phanerochaete Chrysosporium growth and degradation of multisubstrate on a batch process with limited oxygen conditions, that of the effects the initial moisture content (IMC). The study was conducted on the pretreatment of water hyacinth (WH), to degrade the lignin in order to prepare the WH as a bioethanol feedstock. In this pretreatment, the fungus was inoculated on WH where it grew on the surface of the WH. The fungus consumed three different substrates contained in WH as carbon source, i.e. lignin, cellulose and hemicellulose. Experimental data are used to formulate multisubstrate degradation and fungal growth influenced by the IMC. The constant of fungal growth (μ) is influenced by the amount of the initial moisture content (IMC) following the equation with μmax value of 0.6887 day-1, KSL reached 0.7967 g.g dry weight-1, KsS is 0.7102 g.g dry weight-1, KsH is 0.1965 g.g dry weight-1, Yx/sL is 0.13 g.g dry weight of lignin-1, Yx/sS is 0.8560 g.g dry weight of cellulose-1, Yx/sH is 0.8999 g.g dry weight of hemicellulose-1 and the maximum of IMC (Wm) is 0.67 or 67%.

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