Modelagem matemática para descrição da cinética de secagem do caldo de cana in natura

The aim of this work was to determine the drying kinetics in the foam layer of fresh cane broth with the addition of 2,0% Emustab®, 2,0% Super Neutral® and 1,0% phosphate At temperatures of 50, 60 and 70ºC and a total of 0,5 cm of thickness in the foam layer, which will be homogenized in the domestic mixer at the maximum speed for 30 min for foaming formation with approximately 0,500 g/cm3 of density . During the drying process in the foam layer, we monitored the drying kinetics by weighing the trays at regular intervals until we had constant weight. The drying data enabled the calculation of the values of the water content ratio and the construction of drying kinetics curves. Then we constructed the drying curves and adjusted the two-term models Henderson & Pabis, Henderson, Logarithmic, Page and Exponential to the experimental data of the drying kinetics. It was found that the drying temperatures influenced the drying time, in other words the shortest drying time was observed at the highest temperature. Drying times were 665, 545 and 485 minutes at temperatures of 50, 60 and 70°C whilst the thicknesses were 0,5 cm respectively. The drying time has been reduced more rapidly with the increase of the drying air temperature. The Henderson model was the one that described the most satisfactory data of the foam drying, presenting the highest coefficient of determination (0,9935) and the lowest square deviation (0,0007) at the temperature of 50 and thicknesses of 0,5 cm.

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Thin Layer Mathematical Modelling of Cob Maize in a Natural Convection Solar Drier

Energy and Environment Research ◽

10.5539/eer.v7n2p37 ◽

2017 ◽

Vol 7 (2) ◽

pp. 37

Author(s):

M Mukwangole ◽

I. N. Simate

Keyword(s):

Natural Convection ◽

Relative Humidity ◽

Moisture Content ◽

Coefficient Of Determination ◽

Drying Time ◽

Ambient Relative Humidity ◽

Safe Level ◽

Content Ratio ◽

Drying Curves ◽

Maize Cobs

A semi- cylindrical natural convection solar tunnel drier (STD) was used for experiments to dry maize cobs that were partially field- dried. The air temperature recorded in the collector unit was higher than ambient temperature by 15.8oC to 20.8oC and this was effective in reducing the moisture content of maize cobs from 30 % wet basis to safe level storage moisture content of 12.5 % wet basis. Averages of solar radiation recorded during the experiments ranged from 585.6 W/m2 to 759.8 W/m2. The averages of relative humidity that prevailed in the drying unit ranged from 6.8 % to 18.2 % whereas the ambient relative humidity averaged from 27.3 % to 43.7 %. Drying time was examined with moisture content ratio as exponential and polynomial correlations. Fourteen different drying mathematical models available in literature were compared using their coefficients of determination to estimate solar drying curves. Based on statistical analysis of the results, Midilli drying model had the best fit to the experimental drying data of maize with a coefficient of determination R2= 0.99912 as compared to other models.

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FOAM-MAT DRYING KINETICS OF KEITT MANGO PULP

Revista Caatinga ◽

10.1590/1983-21252017v30n119rc ◽

2017 ◽

Vol 30 (1) ◽

pp. 172-180 ◽

Cited By ~ 3

Author(s):

MARY KARLLA ARAÚJO GUIMARÃES ◽

◽

ROSSANA MARIA FEITOSA DE FIGUEIRÊDO ◽

ALEXANDRE JOSÉ DE MELO QUEIROZ ◽

Keyword(s):

Drying Kinetics ◽

Foam Layer ◽

Drying Time ◽

Convection Oven ◽

Drying Kinetic ◽

Different Temperatures ◽

Forced Air ◽

Drying Curves ◽

Mango Pulp ◽

Kinetics Of

ABSTRACT This study aimed to assess the foam-mat drying kinetics of mango pulp (cv. Keitt) adding 1% Emustab® and 1% Super Liga Neutra®, for a whipping time of 20 minutes, dried in a forced -air convection oven at different temperatures (50, 60 and 70oC) and foam layer thicknesses (0.5, 1.0 and 1.5 cm). Drying kinetic data were used to build drying curves and then fit to Page, Henderson, Henderson and Pabis, Logarithmic and two-term Exponential models. Both temperature and foam layer thickness influenced drying time, which reached the shortest value at the highest temperature and smallest thickness. The Page model provided the best fit to the experimental drying curve data.

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Kinetics of drying of basil leaves (Ocimum basilicum L.) in the infrared

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/s1415-43662012001200012 ◽

2012 ◽

Vol 16 (12) ◽

pp. 1346-1352 ◽

Cited By ~ 2

Author(s):

Renata C. dos Reis ◽

Ivano A. Devilla ◽

Diego P. R. Ascheri ◽

Ana C. O. Servulo ◽

Athina B. M. Souza

Keyword(s):

Experimental Data ◽

Ocimum Basilicum ◽

Coefficient Of Determination ◽

Chisquare Test ◽

The Mean ◽

Drying Curves ◽

The One ◽

Increasing Temperature ◽

Air Circulation ◽

Kinetics Of

The objective of this paper was to model the drying curves of the leaves of basil (Ocimum basilicum L.) in the infrared at temperatures of 50, 60, 70 and 80 ºC and to evaluate the influence of drying temperature on the color of dried leaves. Drying was conducted in infrared dryer with temperature and greenhouse air circulation. Experimental data were fitted to eight mathematical models. The magnitude of the coefficient of determination (R²), the mean relative error (P), the estimated mean error (SE) and chisquare test (χ2) were used to verify the degree of fitness of the models. From the study it was concluded that: a) the behavior of the drying curves of basil leaves was similar to most agricultural products, the drying times in the infrared were less than the drying times in an oven with air circulation, b) the mathematical drying model proposed by Midilli et al. (2002) was the one which best adjusted to the experimental data, c) the diffusion coefficient ranged from 9.10 x 10-12 to 2.92 x 10-11 m² s-1 and d) the color of the samples was highly influenced by drying, becoming darker due to loss of chlorophyll with increasing temperature.

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Mathematical modeling of pequi pulp drying and effective diffusivity determination

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n7p493-498 ◽

2017 ◽

Vol 21 (7) ◽

pp. 493-498 ◽

Cited By ~ 3

Author(s):

Elisabete P. de Sousa ◽

Rossana M. F. de Figueirêdo ◽

Josivanda P. Gomes ◽

Alexandre J. de M. Queiroz ◽

Deise S. de Castro ◽

...

Keyword(s):

Experimental Data ◽

Effective Diffusivity ◽

Drying Kinetics ◽

Convective Drying ◽

Drying Time ◽

Air Speed ◽

Drying Curves ◽

Increasing Temperature ◽

Kinetics Of ◽

Best Fit

ABSTRACT The aim of this work was to study the drying kinetics of pequi pulp by convective drying at different conditions of temperature (50, 60, 70 and 80 °C) and thickness (0.5, 1.0 and 1.5 cm) at the air speed of 1.0 m s-1, with no addition of adjuvant. The experimental data of pequi pulp drying kinetics were used to plot drying curves and fitted to the models: Midilli, Page, Henderson & Pabis and Newton. Effective diffusivity was calculated using the Fick’s diffusion model for a flat plate. It was found that, with increasing thickness, the drying time increased and, with increasing temperature, the drying time was reduced. The Midilli model showed the best fit to the experimental data of pequi pulp drying at all temperatures and thicknesses, presenting higher coefficients of determination (R2), indicating that this model satisfactorily represents the pequi pulp drying phenomenon. There was a trend of increase in the effective diffusivity with the increase in pulp layer thickness and temperature.

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THE EFFECT OF THE FILLING RATIO ON THE OPERATING CHARACTERISTICS OF AN INDIRECT DRUM DRYER

Acta Polytechnica ◽

10.14311/ap.2020.60.0049 ◽

2020 ◽

Vol 60 (1) ◽

pp. 49-55

Author(s):

Jan Havlík ◽

Tomáš Dlouhý ◽

Michel Sabatini

Keyword(s):

Specific Energy Consumption ◽

Filling Ratio ◽

Operating Characteristics ◽

Drying Time ◽

Green Wood ◽

Operational Characteristics ◽

Rotary Drum ◽

Drying Curves ◽

The One ◽

Drying Conditions

This article investigates the effect of the filling ratio of the indirect rotary dryers on their operating characteristics. For moist biomass drying before combustion, the use of indirect drum dryers heated by a low pressure steam has proven to be highly suitable. Regarding the design of new dryers, it is necessary to experimentally verify the operating characteristics for specific materials and drying conditions. For this purpose, a set of experiments on a steam heated rotary drum dryer were carried out with green wood chips containing 60 to 66 wt% of moisture. The following operational characteristics of the dryer were experimentally determined: drying curves describing the process, square and volumetric evaporation capacities and drying heat consumptions. Based on the experimental results, the effect of various drum filling by dried material on the mentioned operating characteristics was analysed. On the one hand, higher drum filling ratio increases the drying time, on the other hand, the evaporation capacity also increases, while the specific energy consumption does not significantly alter. The maximum value of the evaporation capacity was reached when the drum was filled to 20 wt%. When the filling ratio was increased to 25 wt%, the evaporation capacity experienced almost no change.

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The thin-layer drying characteristics of sewage sludge by the appropriate foaming pretreatment

Water Science & Technology ◽

10.2166/wst.2014.093 ◽

2014 ◽

Vol 69 (9) ◽

pp. 1859-1866 ◽

Cited By ~ 4

Author(s):

Hui-Ling Wang ◽

Zhao-Hui Yang ◽

Jing Huang ◽

Li-Ke Wang ◽

Cheng-Liu Gou ◽

...

Keyword(s):

Sample Thickness ◽

Coefficient Of Determination ◽

Drying Rate ◽

Drying Time ◽

Drying Characteristics ◽

Thin Layer Drying ◽

Dewatered Sludge ◽

Drying Curves ◽

Sludge Drying ◽

The Impact

As dewatered sludge is highly viscous and sticky, the combination of foaming pretreatment and drying process seems to be an alternative method to improve the drying performance of dewatered sludge. In this study, CaO addition followed by mechanical whipping was employed for foaming the dewatered sludge. It was found that the foams were stable and the diameters of bubbles mainly ranged from 0.1 to 0.3 mm. The drying experiments were carried out in a drying oven in the convective mode. The results indicated that foamed sludge at 0.70 g/cm3 had the best drying performance at each level of temperature, which could save 35–45% drying time to reach 20% moisture content compared with the non-foamed sludge. The drying rate of foamed sludge at 0.70 g/cm3 was improved with the increasing of drying temperature. The impact of sample thickness on drying rate was not obvious when the sample thickness increased from 2 to 8 mm. Different mathematical models were used for the simulation of foamed sludge drying curves. The Wang and Singh model represented the drying characteristics better than other models with coefficient of determination values over 0.99.

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Effects of Infrared-Assisted Refractance Window™ Drying on the Drying Kinetics, Microstructure, and Color of Physalis Fruit Purée

Foods ◽

10.3390/foods9030343 ◽

2020 ◽

Vol 9 (3) ◽

pp. 343

Author(s):

Luis Puente-Díaz ◽

Oliver Spolmann ◽

Diego Nocetti ◽

Liliana Zura-Bravo ◽

Roberto Lemus-Mondaca

Keyword(s):

Statistical Tests ◽

Coefficient Of Determination ◽

Drying Process ◽

Chi Square ◽

Ir Radiation ◽

Drying Time ◽

Drying Curves ◽

Effective Diffusivities ◽

Drying Conditions ◽

Fruit Purée

The objective of this work was to study the influence of the drying temperature, infrared (IR) radiation assistance, and the Mylar™ film thickness during Physalis fruit purée drying by the Refractance Window™ (RW™) method. For this, a RW™ dryer layout with a regulated bath at working temperatures of 60, 75, and 90 °C, Mylar™ thicknesses of 0.19, 0.25, 0.30 mm and IR radiation of 250 W for assisting RW™ drying process was used. Experimental curves data were expressed in moisture ratio (MR) in order to obtain moisture effective diffusivities (non-assisted RW™: Deff = 2.7–10.1 × 10−10 m2/s and IR-assisted RW™: Deff = 4.2–13.4 × 10−10 m2/s) and further drying curves modeling (Page, Henderson–Pabis, Modified Henderson–Pabis, Two-Term, and Midilli–Kucuk models). The Midilli–Kucuk model obtained the best-fit quality on experimental curves regarding statistical tests applied (Coefficient of Determination (R2), Chi-Square (χ2) and Root Mean Square Error (RMSE). Microscopical observations were carried out to study the RW™ drying conditions effect on microstructural changes of Physalis fruit purée. The main findings of this work indicated that the use of IR-assisted RW™ drying effectively accelerates the drying process, which achieved a decrease drying time around 60%. Thus, this combined RW™ process is strongly influenced by the working temperature and IR-power applied, and slightly by Mylar™ thickness.

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Modelling the Drying Characteristics and Kinetics of Hot Air-Drying of Unblanched Whole Red Pepper and Blanched Bitter Leaf Slices

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v5i1.24-32.775 ◽

2017 ◽

Vol 5 (1) ◽

pp. 24

Author(s):

Samuel Enahoro Agarry

Keyword(s):

Moisture Diffusivity ◽

Effective Moisture Diffusivity ◽

Red Pepper ◽

Coefficient Of Determination ◽

Drying Time ◽

Drying Characteristics ◽

Hot Air ◽

Effective Moisture ◽

Drying Curves ◽

Kinetics Of

The objective of this study was to investigate the drying characteristics and kinetics of red pepper and bitter leaf under the influence of different drying temperatures. The drying experiments were carried out at dry bulb temperature of 35, 45, 55 and 75oC, respectively in an oven dryer. The results showed that as drying temperature increased, drying rate also increased and the drying time decreased. It was observed that un-sliced red pepper and sliced bitter leaf would dry within 2.5-12 h and 1.67-7 h, respectively at temperature ranging from 75 to 35oC. The drying of red pepper and bitter leaf was both in the constant and falling rate period. Four semi-empirical mathematical drying models (Newton, Page, Henderson and Pabis, and Logarithmic models) were fitted to the experimental drying curves. The models were compared using the coefficient of determination (R^2) and the root mean square error (RMSE). The Page model has shown a better fit to the experimental drying data of red pepper and bitter leaf, respectively as relatively compared to other tested models. Moisture transport during drying was described by the application of Fick’s diffusion model and the effective moisture diffusivity was estimated. The value ranges from 15.69 to 84.79 × 10-9 m2/s and 0.294 to 1.263 × 10-9 m2/s for red pepper and bitter leaf, respectively. The Arrhenius-type relationship describes the temperature dependence of effective moisture diffusivity and was determined to be 37.11 kJ/mol and 32.86 kJ/mol for red pepper and bitter leaf, respectively. A correlation between the drying time and the heat transfer area was also developed.

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MATHEMATICAL MODELING OF THE DRYING CURVES OF FOXTAIL MILLET SEEDS IN SPOUTED BED

Revista de Engenharia Térmica ◽

10.5380/reterm.v14i2.62127 ◽

2015 ◽

Vol 14 (2) ◽

pp. 18

Author(s):

L. D. Do Nascimento ◽

L. G. Corumbá ◽

S. C. S. Rocha ◽

O. P. Taranto ◽

C. M. L. Costa ◽

...

Keyword(s):

Statistical Tests ◽

Diffusion Mechanism ◽

Foxtail Millet ◽

Drying Kinetics ◽

Coefficient Of Determination ◽

Spouted Bed ◽

Drying Kinetic ◽

Different Temperatures ◽

Drying Curves ◽

Quasi Newton

In order to provide a contribution to future studies of foxtail millet (Setaria italica), the drying kinetics of the seeds was investigated at three different temperatures: 44, 65 and 86°C. The seeds of S. italica with a moisture equal to 30% in dry basis were dried in a conical-cylindrical spouted bed during an interval of 132 min. Some empirical mathematical models were selected to describe the experimental drying kinetics data (Lewis, Henderson and Pabis, Page, Diffusion approach, Midilli and Wang and Singh) and the best models were chosen according to the statistical tests results (coefficient of determination, mean relative percent deviation, mean square root error and residue distribution), using the software Statistica® 7.0 and applying the Quasi-Newton method. Only the decreasing rate period was observed in the drying kinetic curves, indicating that the removal of moisture content was preferably by the diffusion mechanism, which is a characteristic behavior of fibrous products, like the agricultural products. The models of Diffusion Aproach, Page and Midilli were the most suitable to describe the experimental drying curves.

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Modelagem matemática para a descrição da cinética de secagem do fruto da palma (Opuntia fícus indica)

Revista Verde de Agroecologia e Desenvolvimento Sustentável ◽

10.18378/rvads.v11i1.3897 ◽

2016 ◽

Vol 11 (1) ◽

pp. 01

Author(s):

A. E. Santos ◽

G. M. V. Martins ◽

M. F. C. S. Canuto ◽

J. E. D. Vieira Segundo ◽

R. D. Almeida

Keyword(s):

Thin Layer ◽

Drying Kinetics ◽

Coefficient Of Determination ◽

Font Size ◽

Drying Time ◽

Palm Fruit ◽

Opuntia Ficus Indica ◽

Thin Layer Drying ◽

Kinetics Of ◽

Background Image

O presente trabalho teve como objetivo estudar a secagem em camada fina do fruto da palma (Opuntia fícus indica) nas temperaturas de 50, 60 e 70 °C em estufa com circulação forçada de ar. Foram empregados os modelos matemáticos de Aproximação da difusão, Logaritmico, Midilli e Page. Como critério de avaliação utilizou-se o coeficiente de determinação e o desvio quadrático médio (). Mediante os resultados obtidos observou-se que o aumento da temperatura diminuiu o tempo de secagem do fruto. Dentre os modelos aplicados o Logarítmico apresentou os maiores valores de coeficiente de determinação R² e os menores valores de DQM para a faixa de temperatura e espessura estudadas.<span style="font-size: 14pt; font-family: 'Times New Roman', serif; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;" lang="EN-US">Mathematical modeling for description of the pulp drying kinetics of palm fruit (Opuntia fícus indica)<span style="font-size: 9pt; font-family: 'Times New Roman', serif; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;" lang="EN-US"> <span style="font-size: 10pt; font-family: 'Times New Roman', serif; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;" lang="EN-US">Abstract<span style="font-size: 10pt; font-family: 'Times New Roman', serif; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;" lang="EN-US">: This work was developed with the aimed of to study ing the thin layer drying of palm fruit pulp oiti at temperatures of 122, 140 and 158 °Fahrenheit in an oven with forced air circulation. For the representation of the drying kinetics of thin-layer were used mathematical models of the diffusion approximation, logarithmic, and Midilli Kucuk and Page, and as a criterion for evaluating these we used the coefficient of determination and the deviation quadratic mean (DQM). From tThe results obtained showed that the increase in temperature decreases the drying time of the palm fruit. Among the models applied to Logarithmic the had the highest R2 values and lower values of DQM for the temperature and layer thickness range studied.

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