Drying kinetics of cotton based yarn bobbins in a pressurized hot-air convective dryer

2016 ◽  
Vol 231 (2) ◽  
pp. 294-308
Author(s):  
Dinçer Akal ◽  
Kamil Kahveci ◽  
Ugur Akyol ◽  
Ahmet Cihan
Keyword(s):  
Energy Consumption ◽  
Minimum Energy ◽  
Effective Diffusion ◽  
Volumetric Flow Rate ◽  
Drying Kinetics ◽  
Drying Time ◽  
Flow Rates ◽  
Minimum Energy Consumption ◽  
Hot Air ◽  
Kinetics Of

In this study, the drying kinetics of cotton bobbin drying process in a pressurized hot-air convective bobbin dryer was investigated, and a drying model was introduced for the simulation of drying. Tests were conducted for drying temperatures of 70℃, 80℃, and 90℃; effective drying air pressures of 1, 2, and 3 bars; three volumetric flow rates of 42.5, 55, and 67.5 m3/h; and for three different bobbin diameters of 10, 14, and 18 cm. Optimum drying conditions were specified in terms of drying time and energy consumption. Results indicate that the total drying time depends significantly on the drying temperature, pressure, and volumetric flow rate. Results show that the minimum energy consumption is obtained for low values of drying air temperatures and pressures, and for moderate and high values of drying air volumetric flow rates. It was also found that the Page model is suitable for simulating the drying behavior of cotton yarn bobbins. Finally, results show that effective diffusion coefficient values are between 1.132 × 10−7 m2/s and 3.453×10−7 m2/s depending on the values of drying parameters.

scholarly journals The Experimental Research of Drying Kinetics of Nagpur Orange Fruit (Citrus Sinesis- L) by Hot Air Electrical Dryer

2019 ◽  
Vol 8 (6S4) ◽  
pp. 1131-1134
Keyword(s):  
Thin Layer ◽  
Drying Kinetics ◽  
Drying Time ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Orange Fruit ◽  
Kinetics Of

The study is aimed experimentally and compared with the theoretical results of drying kinetics of Nagpur orange fruit dried in a hot air electrical dryer. Orange fruit is highly perishable and needs to be consumed or processed immediately after harvest. Drying or dehydration is one of the most practical methods of preserving food products. Therefore, thin layer drying characteristics of falling rate of Nagpur orange are determined experimentally under different conditions of drying air temperatures, relative humidity and air velocities for different moisture contents. Thin layer models like Wang and Singh, Page and Henderson have been compared with Experimental results. The knowledge of drying kinetics helps for identification of exact drying time and air flow velocity for different moisture content. Here drying operation is carried out at a velocity of 1m/sec and 1.25 m/sec for different temperature of 55°C, 65°C and 75°C. This analysis reveals that drying temperature has a more significant effect on moisture removal while velocity has the least effect. Drying rate is found to increase with the increase in drying temperature and reduce with drying time. Experimental data is statistically correlated by plotting the drying characteristics curve. The analysis reveals that Wang and Singh's model is a better model to explain the drying behavior of Nagpur Orange fruit (R2=0.9888).

The Drying Kinetics of Natural Rubber Sheets under Hot-Air Drying with Forced Convection: Experiments and Modeling

2013 ◽  
Vol 844 ◽  
pp. 154-157
Author(s):  
Warit Werapun ◽  
Yutthapong Pianroj ◽  
Pinpong Khongchana
Keyword(s):  
Natural Rubber ◽  
Linear Regression Analysis ◽  
Effective Diffusion ◽  
Drying Kinetics ◽  
Heat Sources ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Liquid Petroleum Gas ◽  
Kinetics Of

This study investigated the drying kinetics of the natural rubber sheets under hot air drying, with various heat sources, and included modeling of the kinetics. The heat was generated by combustion, either of charcoal briquettes from coconut shell (biomass) or of liquid petroleum gas (LPG). The hot air entering the drying chamber had its initial temperature controlled at 40, 50, or 60 Centigrade. Five rubber sheets within the chamber were observed during their drying. Howerver, in the case of biomass, the fuctuation of temperature due to charcoal adding. Therfore, the non-linear regression analysis was performed only LPG data with a Weibull distribution and a Modified Handerson and Pabis. They represented the drying kinetics with parametric fits; moreover, an effective diffusion coefficient was determined for each experimental condition.

scholarly journals Effect of Freeze-Thaw Cycles on Juice Properties, Volatile Compounds and Hot-Air Drying Kinetics of Blueberry

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2362
Author(s):  
Lin Zhu ◽  
Xianrui Liang ◽  
Yushuang Lu ◽  
Shiyi Tian ◽  
Jie Chen ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Drying Kinetics ◽  
Soluble Solids ◽  
Hot Air Drying ◽  
Fresh Sample ◽  
Drying Time ◽  
Air Drying ◽  
Freeze Thaw ◽  
Hot Air ◽  
Kinetics Of

This paper studied the effects of freeze-thaw (FT) cycles on the juice properties and aroma profiles, and the hot-air drying kinetics of frozen blueberry. After FT treatment, the juice yield increased while pH and total soluble solids of the juice keep unchanged. The total anthocyanins contents and DPPH antioxidant activities of the juice decreased by FT treatments. The electronic nose shows that FT treatments significantly change the aroma profiles of the juice. The four main volatile substances in the fresh juice are (E)-2-hexenal, α-terpineol, hexanal and linalyl formate, which account for 48.5 ± 0.1%, 17.6 ± 0.2%, 14.0 ± 1.5% and 7.8 ± 2.7% of relative proportions based on total ion chromatogram (TIC) peak areas. In the FT-treated samples, the amount of (E)-2-hexenal and hexanal decreased significantly while α-terpineol and linalyl formate remained almost unchanged. Repeated FT cycles increased the ethanol content and destroyed the original green leafy flavor. Finally, the drying kinetics of FT-treated blueberries was tested. One FT treatment can shorten the drying time by about 30% to achieve the same water content. The Deff values of the FT-treated sample are similar, which are about twice as large as the value of the fresh sample. The results will be beneficial for the processing of frozen blueberry into juice or dried fruits.

scholarly journals Drying kinetics and effective diffusion of buckwheat grains

2020 ◽  
Vol 44 ◽  
Author(s):  
Valdiney Cambuy Siqueira ◽  
Rafael Araújo Leite ◽  
Geraldo Acácio Mabasso ◽  
Elton Aparecido Siqueira Martins ◽  
Wellytton Darci Quequeto ◽  
...  
Keyword(s):  
Effective Diffusion ◽  
Information Criterion ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Linear Regression Method ◽  
Drying Process ◽  
Food Sector ◽  
Drying Time ◽  
Air Speed ◽  
Kinetics Of

ABSTRACT Buckwheat has become important in the food sector as its flour does not contain gluten. Since buckwheat is a relatively new crop in the agricultural environment, there is little information available regarding its processing. Drying is one of the most important post-harvest stages of buckwheat. The aim of the present study was to describe the drying process of buckwheat grains. Buckwheat grains with a moisture content of 0.41 ± 0.01 (dry basis, d.b.) were harvested, followed by drying in an experimental dryer at the temperatures of 40, 50, 60, 70, and 80 °C, at an air speed of 0.8 m s-1. The drying rate was determined, and the mathematical models generally employed to describe the drying process of several agricultural products were fitted to the experimentally obtained data. Model selection was based on the Gauss-Newton non-linear regression method and was complemented by Akaike Information Criterion and Schwarz’s Bayesian Information Criterion. It was concluded that the drying rate increased with an increase in temperature and decreased with an increase in drying time. It is recommended to use the Midilli model to represent the drying kinetics of buckwheat grains at the temperatures of 40, 60, and 70 °C, while the Approximation of diffusion model is recommended for the temperatures of 50 and 80 °C. The magnitudes of effective diffusion coefficients ranged from 1.8990 × 10-11 m2 s-1 to 17.8831 × 10-11 m2 s-1. The activation energy required to initiate the drying process was determined to be 49.75 kJ mol-1.

scholarly journals Drying kinetics of blackberry leaves

2018 ◽  
Vol 22 (8) ◽  
pp. 570-576 ◽  
Author(s):  
Elton A. S. Martins ◽  
André L. D. Goneli ◽  
Alexandre A. Goncalves ◽  
Cesar P. Hartmann Filho ◽  
Valdiney C. Siqueira ◽  
...  
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficient ◽  
Effective Diffusion Coefficient ◽  
Effective Diffusion ◽  
Fixed Bed ◽  
Drying Kinetics ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Air Speed ◽  
Kinetics Of

ABSTRACT Blackberry leaves have some pharmacological properties and one of the most widespread and studied uses is to relieve symptoms of the climacteric and other symptoms during the premenstrual period. Thus, drying becomes important for the conservation and storage of the product until its use or processing. The present study aimed to evaluate the drying kinetics of blackberry leaves, as well as to determine the effective diffusion coefficient and the activation energy during the drying process. Blackberry leaves were dried in an experimental fixed-bed dryer under four controlled temperature conditions (40, 50, 60 and 70 °C) and two drying air speeds (0.4 and 0.8 m s-1). With the experimental data of moisture ratio, eight mathematical models were fitted to represent the process of thin-layer drying of agricultural products. Based on the obtained results, it was found that the Midilli model represented best the phenomenon of drying of blackberry leaves. The increase in temperature and air speed reduced the drying time of blackberry leaves and increased the values of the effective diffusion coefficient. This relation can be described by the Arrhenius equation, which has an activation energy for the liquid diffusion during drying of 65.94 and 66.08 kJ mol-1, for drying air speeds of 0.4 and 0.8 m s-1, respectively.

scholarly journals Modelling the Thin-Layer Drying Kinetics of Marinated Beef during Infrared-Assisted Hot Air Processing of Biltong

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Francis C. Muga ◽  
Moses O. Marenya ◽  
Tilahun S. Workneh
Keyword(s):  
Drying Kinetics ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Emitter Temperature ◽  
The Core ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Rate Period ◽  
Kinetics Of

Biltong is a dried meat product that is widely consumed in South Africa. The marinated meat is traditionally dried under ambient winter conditions while commercial biltong producers use hot air driers. Hot air drying is time-consuming and energy-intensive. A combined infrared and hot air drying (IRHAD) is an alternative method of drying meat during biltong processing. The aim of this study was to establish the effect of the infrared (IR) power, the temperature, and velocity of the drying air on the drying kinetics of marinated beef and subsequently select the best thin-layer drying model for IRHAD during biltong processing. Marinated beef samples were dried at IR power levels of 500, 750, and 1000 W; drying air temperatures of 30, 35, and 40°C; and air velocity of 1.5 and 2.5 m∙s-1. Results indicate that increasing the IR power and the drying air temperature increased the IR emitter temperature and the core temperature of the marinated beef sample. Consequently, increasing the drying rate thus reduced drying time. The air velocity had an inverse relationship with the IR emitter temperature, the core temperature of the marinated beef sample, and the drying rate. The drying process was characterised by a rising rate period in the first half an hour, followed by a falling rate period which implies that moisture transport occurred partly by surface evaporation and predominantly by diffusion. The effective moisture diffusivity ranged from 4.560 × 10 − 10 to 13.7 × 10 − 10   m 2 ∙ s − 1 , while, the activation energy ranged between 40.97 and 59.16 kJ∙mol-1. The IRHAD of marinated beef during its processing to biltong was best described by the two-term model since it had the highest R 2 (0.9982-0.9993) and the lowest RMSE (0.0062-0.0099). The power level of the IR emitter of 1000 W combined with a drying air temperature and velocity of 40°C and 1.5 m∙s-1, respectively, showed the highest improvement in the drying kinetics and the lowest drying time of 5.61 ± 0.35 hours; hence, it is recommended as a possible drying alternative for the processing of biltong.

scholarly journals Influence of UV-B Pretreatments on Kinetics of Convective Hot Air Drying and Physical Parameters of Mushrooms (Agaricus bisporus)

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 371
Author(s):  
Arman Forouzanfar ◽  
Mohammad Hojjati ◽  
Mohammad Noshad ◽  
Antoni Jacek Szumny
Keyword(s):  
Control Sample ◽  
Moisture Diffusion ◽  
Drying Kinetics ◽  
Ultraviolet B ◽  
Physical Parameters ◽  
Chi Square ◽  
Drying Time ◽  
Color Changes ◽  
Hot Air ◽  
Kinetics Of

The present study aimed to investigate the effects of ultraviolet-B (UV-B) pretreatments on selected physical properties (shrinkage, rehydration, color, texture) and drying kinetics and to model the drying kinetics of hot air dried mushrooms using several mathematical models, such as the Henderson–Pabis, logarithmic, two-term, Verma, Wang and Singh, Midilli, and modified Henderson–Pabis models. Results showed that the use of UV-B pretreatment before mushroom drying reduced shrinkage, color changes, firmness, and drying time and increased rehydration and the effective moisture diffusion coefficient. The amount of activation energy increased from 16.55 ± 1.3 kJ/mol (control sample) to 18.27 ± 2.2 kJ/mol (UV-B treated samples for 30 min), 19.72 ± 1.4 kJ/mol (UV-B treated samples for 60 min), and 21.9 ± 1.9 kJ/mol (UV-B treated samples for 90 min). However, increasing the drying temperature increased the shrinkage and firmness of samples. The modified Henderson–Pabis model with the highest correlation coefficient (R2) and lowest root mean square error (RMSE) and chi-square (χ2) showed the best fit for every drying curve, proving to be an excellent tool for the prediction of drying time.

scholarly journals Drying kinetics of Hyola 430 hybrid canola (Brassica napus L.) seeds

2020 ◽  
pp. 1623-1629
Author(s):  
Lílian Moreira Costa ◽  
Osvaldo Resende ◽  
Daniel Emanoel Cabral de Oliveira ◽  
José Mauro Guimarães Carvalho ◽  
Sarah Gabrielle Sousa Bueno ◽  
...  
Keyword(s):  
Moisture Content ◽  
Mathematical Models ◽  
Effective Diffusion ◽  
Initial Moisture Content ◽  
Information Criteria ◽  
Drying Kinetics ◽  
Coefficient Of Determination ◽  
Statistical Parameters ◽  
Drying Time ◽  
Kinetics Of

This work aimed to study the drying kinetics of canola seeds, fit mathematical models and obtain the effective diffusion coefficient. Canola seeds with initial moisture content of 0.3653 (decimal, d.b.) were subjected to drying in a forced ventilation oven at temperatures of 40, 60, 80 and 100 °C and relative humidity of 37.15, 16.93, 8.35, 4.41 and 2.47%, respectively. The samples were dried on trays without perforations, containing approximately 77 g, in three replicates. A final moisture content of 0.080 ± 0.004 (decimal, d.b.) was established to determine the drying curves and fit the mathematical models. The mathematical models were selected considering the mean estimated error, chi-square, coefficient of determination, mean relative error, and Akaike (AIC) and Bayesian (BIC) information criteria. Drying time decreased with increasing temperature. Based on the best values of the statistical parameters and together with the Akaike and Bayesian information criteria, the Page model was selected to represent the drying kinetics of canola seeds. The effective diffusion coefficients showed magnitudes between 0.153x10-11 and 1.221x10-11 (m2 s-1), and their values increased with temperature increase, being described by the Arrhenius equation, with activation energy of 33.94 kJ mol-1, an important piece of information to consider when designing drying equipment

scholarly journals The Effect of Vacuum Impregnation Pretreatment on Air-Drying Kinetics of Pears

2020 ◽  
Vol 8 (11) ◽  
pp. 2248-2254
Author(s):  
Şeyma Uysal ◽  
Fikret Pazır
Keyword(s):  
Effective Diffusion ◽  
Solution Concentration ◽  
Drying Kinetics ◽  
Vacuum Impregnation ◽  
Drying Process ◽  
Drying Time ◽  
Air Drying ◽  
Pyrus Communis L ◽  
Experimental Values ◽  
Kinetics Of

The aim of this study was to examine the drying kinetics of pears (Pyrus communis L.) with and without vacuum impregnation and under the different temperature by using tray dryer. Vacuum impregnation were applied to the the pears (15 mm thickness, 65 mm outer and 20 mm inner dimensions respectively) with the conditions of 50⁰ Brix impregnation solution concentration, 225 mbar vacuum pressure and 45 min vacuum time. Drying process was carried out at temperatures of 55, 65 and 75°C. Drying time of non-vacuum impregnated pears was determined 640, 500 and 340 min and vacuum impregnated pears was determined 700, 540 and 560 min respectively. Page, Exponential, Henderson and Pabis, Diffusion Approach were examined for testing the drying kinetics. Experimental values are in accordance with the expected values resulted Page and Difussion models of with and without vacuum impregnated pears. Effective diffusion coefficient (Deff) was varying 2.74×10-11 to 7.31×10-11 m2/s. m2/s with respect to the drying temperatures. The activation energy for the non-vacuum impregnated and vacuum impregnated pears was 32.93 kJ / mol and 24.25 kJ / mol, respectively.

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