Study of the drying kinetics of red chili (Capsicum annuum) in an indirect solar dryer tunnel type

The drying process is very intensive in energy consumption. Mexico is a major producer of food, especially of varieties of chilies, with quality culinary and medicinal properties. The 65% of the national market as a dry product, which gives a benefit. In the drying process, the convective technology was used, using a horizontal tunnel with direct solar heating air. The kinetics of the solar dryer with direct heating is possible, with an average drying time of 16 hours of solar irradiance. The tests were performed in Temixco, Morelos, Mexico, located at 18 º 51 'of LN and 99º 14' of LO, with average values of 850 W/m2 irradiance maximum. The chamber temperatures were in a range between 31 and 45 °C. The air velocity range was set between 1.3 and 2.4 m/s. Final moisture contents of the dried chili were obtained in a range between 8% and 6% h.b. with an average drying velocity of 4.7 humidity degree/h. The solar direct drying is a technology that allows recovering and trying different agricultural surpluses and could promote the establishment of agro-industries.

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Effect of Solar Radiation on the Drying Parameters of Mint (Mentha Spicata L.) Dried in Natural Convective Solar Dryer

10.21203/rs.3.rs-117400/v1 ◽

2020 ◽

Author(s):

SEBIHA REHMAN ◽

SEEMIN RUBAB

Keyword(s):

Weather Conditions ◽

Quality Parameter ◽

Drying Process ◽

Kashmir Valley ◽

Rehydration Ratio ◽

Drying Time ◽

Mentha Spicata ◽

Solar Dryer ◽

Pre Treatment ◽

Kinetics Of

Abstract The paper presents a kinetic study of solar dried mint (Mentha spicata L.) without any pre-treatment. Mint grows effortlessly in Kashmir valley but is not obtainable throughout the year because of inconsiderate weather conditions. The genus belongs to the Labiatae family and includes large varieties with different properties. A significant quality parameter is its colour. The drying kinetics of mint leaves dried in Domestic Solar Dryer in terms of colour attributes, moisture content, drying time, non enzymatic browning, water activity, rehydration ratio was studied. This study is very useful for household scale drying of mint leaves to optimize drying process and to achieve superior quality dried product at home maintaining its colour and aroma.

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Thin-Layer Mathematical Modeling of Turmeric in Indirect Natural Conventional Solar Dryer

Journal of Solar Energy Engineering ◽

10.1115/1.4045828 ◽

2020 ◽

Vol 142 (4) ◽

Cited By ~ 3

Author(s):

Masnaji R. Nukulwar ◽

Vinod B. Tungikar

Keyword(s):

Mathematical Modeling ◽

Moisture Content ◽

Thin Layer ◽

Air Velocity ◽

Drying Time ◽

Sun Drying ◽

Solar Dryer ◽

Air Temperatures ◽

Drying Efficiency ◽

Kinetics Of

Abstract The objective of this study is to find an optimized thin-layer mathematical model suitable for drying kinetics of turmeric. Turmeric has a high moisture content which necessitates effective drying. A 10 kg, sample batch, of turmeric was dried in a solar dryer. Drying air temperatures and air velocity were observed in the range of 55 °C–68 °C and 0.7 m/s–1.4 m/s, respectively, in the drying experiments. It is seen that the moisture content of the turmeric is reduced from 77% to 11.93% in 22 h when compared with open sun drying, which required 60 h for the same reduction in the moisture content. Scheffler dish was used to generate steam for the dryer. Seven thin-layer mathematical models, cited in the literature, had been used for the study. These models were applied for different trays placed in the dryer. The result of the research and experimentation showed that the Page model fits best for drying in the steam-based dryer and open sun drying. Experimental results showed 63.33% saving in drying time, and the drying efficiency was found as 29.85%. Uncertainty in the drying efficiency was observed as 0.67%. Experimental investigation and the findings from the mathematical modeling are presented in this paper.

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Drying kinetics of mango fruit using tray and oven dryer

Malaysian Journal of Chemical Engineering and Technology (MJCET) ◽

10.24191/mjcet.v3i2.10965 ◽

2020 ◽

Vol 3 (2) ◽

pp. 51

Author(s):

Nurhasmanina Norhadi ◽

Ammar Mohd Akhir ◽

Nor Roslina Rosli ◽

Farid Mulana

Keyword(s):

Moisture Content ◽

Drying Kinetics ◽

Drying Rate ◽

Airflow Rate ◽

Drying Process ◽

Air Velocity ◽

Mango Fruit ◽

Drying Time ◽

Different Temperatures ◽

Kinetics Of

Drying is generally used to increase the shelf life of food products. In this context, mango fruit is used as a sample for the drying process because of its high commercial value and particularly high moisture content. The mango was sliced into few batches of sample with a size of 20 mm × 30 mm × 5 mm each. The experiments were conducted using tray and oven dryer at different temperatures of 40, 50 and 60 °C with a steady airflow rate of 1.3 m/s. The objectives are to study the effect of drying time, temperature and air velocity towards drying of mango fruit, to compare the physical characteristics of mango sample after drying and to determine the best drying kinetics model fitted to each tray and oven dryer. The results showed that the increase in drying time, temperature and air velocity would reduce the moisture content while at the same time, drying rate increased significantly. Tray dryer was found to be more effective than oven dryer because of higher drying rate with better product quality and appearance at the end. Furthermore, the gathered data were fitted into few widely used drying mathematical models and it was found that Henderson and Pabis model at 60°C is best suited for tray dryer whereas Page model at 40 °C is the best for oven dryer.

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Effects of Osmotic Dehydration on the Hot Air Drying of Apricot Halves: Drying Kinetics, Mass Transfer, and Shrinkage

Processes ◽

10.3390/pr9020202 ◽

2021 ◽

Vol 9 (2) ◽

pp. 202

Author(s):

Ivan Pavkov ◽

Milivoj Radojčin ◽

Zoran Stamenković ◽

Krstan Kešelj ◽

Urszula Tylewicz ◽

...

Keyword(s):

Activation Energy ◽

Osmotic Dehydration ◽

Effective Diffusivity ◽

Drying Process ◽

Air Velocity ◽

Hot Air Drying ◽

Drying Time ◽

Air Drying ◽

Hot Air ◽

Kinetics Of

This study aimed to determine the effects of osmotic dehydration on the kinetics of hot air drying of apricot halves under conditions that were similar to the industrial ones. The osmotic process was performed in a sucrose solution at 40 and 60 °C and concentrations of 50% and 65%. As expected increased temperatures and concentrations of the solution resulted in increased water loss, solid gain and shrinkage. The kinetics of osmotic dehydration were well described by the Peleg model. The effective diffusivity of water 5.50–7.387 × 10−9 m2/s and solute 8.315 × 10−10–1.113 × 10−9 m2/s was calculated for osmotic dehydration. Hot air drying was carried out at 40, 50, and 60 °C with air flow velocities of 1.0 m/s and 1.5 m/s. The drying time shortened with higher temperature and air velocity. The calculated effective diffusion of water was from 3.002 × 10−10 m2/s to 1.970 × 10−9 m2/s. The activation energy was sensitive to selected air temperatures, so greater air velocity resulted in greater activation energy: 46.379–51.514 kJ/mol, and with the osmotic pretreatment, it decreased to 35.216–46.469 kJ/mol. Osmotic dehydration reduced the effective diffusivity of water during the hot air drying process. It also resulted in smaller shrinkage of apricot halves in the hot air drying process.

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CATFISH DRYING (Clarias Batraclus) USING ‘TEKO BERSAYAP’ SOLAR DRYER

Jurnal Agroindustri ◽

10.31186/j.agroind.2.1.14-20 ◽

2012 ◽

Vol 2 (1) ◽

pp. 14-20

Author(s):

Yuwana Yuwana

Keyword(s):

Relative Humidity ◽

Moisture Content ◽

Ambient Temperature ◽

Drying Rate ◽

Drying Process ◽

Drying Time ◽

Ambient Relative Humidity ◽

Solar Dryer

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.

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The kinetics of nutritional quality changes during winter jujube slices drying process

Quality Assurance and Safety of Crops & Foods ◽

10.15586/qas.v13i1.824 ◽

2021 ◽

Vol 13 (1) ◽

pp. 73-82

Author(s):

Yubao Niu ◽

Shiyu Wei ◽

Huan Liu ◽

Yongzhen Zang ◽

Yuxue Cao ◽

...

Keyword(s):

Degradation Kinetics ◽

Weibull Model ◽

Reducing Sugar ◽

Total Acidity ◽

Drying Process ◽

Drying Time ◽

Nutrient Quality ◽

Air Impingement ◽

Weibull Models ◽

Kinetics Of

The purpose of this research is to investigate the kinetics of nutrient quality (Vitamin C (Vc), reducing sugar and total acidity) change of winter jujube slices that under different drying temperatures (55, 60, 65 and 70?) and different air velocities (3, 6 and 9m/s) during the air-impingement drying process. Results showed that the content of Vc, reducing sugar and total acidity decreased with increasing drying time. Furthermore, analysis of variances indicated that the drying temperature, air velocity and time had a significant effect on the loss of Vc, reducing sugar and total acidity (p<0.05). Zero order, first order and Weibull models were used to fit the experimental data, Weibull model was considered as the most suitable one to the degradation kinetics of Vc, reducing sugar and total acidity in dried samples at different temperatures and air velocities. According to the Arrhenius formula, the activation energy of Vc, reducing sugar and total acidity degradation kinetics were 63.78 kJ/mol, 36.48 kJ/mol and 153.51 kJ/mol, respectively. This research can provide some references for enhancing dried products quality in the jujube drying industry.

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Experimental Evaluation and Kinetic Analysis of Direct-Contact Ultrasonic Fabric Drying Process

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4047566 ◽

2020 ◽

Vol 13 (2) ◽

Author(s):

Chang Peng ◽

Saeed Moghaddam

Keyword(s):

Direct Contact ◽

Ultrasonic Transducer ◽

Gaussian Model ◽

Weibull Model ◽

Drying Kinetics ◽

Energy Prices ◽

Drying Process ◽

Liquid Form ◽

Drying Time ◽

Kinetics Of

Abstract Over the past two decades, due to the rising energy prices and growing awareness about climate change, significant efforts have been devoted to reducing the energy consumption of various home appliances. However, the energy efficiency of clothes dryers has little improvement. Recent innovations in the direct-contact ultrasonic fabric drying technique offer new opportunities for energy saving. In this technique, high-frequency mechanical vibrations generated by the ultrasonic transducer are utilized to atomize water from a fabric in the liquid form, which demonstrates great potential for reducing energy use and drying time of the fabric drying process. Here, for the first time, fabric drying kinetics under different direct-contact ultrasonic drying conditions were investigated experimentally and analytically. The drying processes of four kinds of fabrics were experimentally tested under different ultrasonic transducer vibration frequency (115, 135, and 155 kHz) and input power (1.2, 2.5, and 4.4 W) conditions. According to the experimental data, five different kinds of models were applied to quantify the drying kinetics of fabrics during direct-contact ultrasonic drying. The models not only incorporated the transducer parameters but also the parameters related to the nature of fabric. Our evaluation results of model prediction performance demonstrated that the two empirical models, i.e., the Weibull model and the Gaussian model, were superior to the three semi-theoretical models for anticipating the drying kinetics of fabrics under direct-contact ultrasonic drying. Furthermore, the Weibull model is more suitable for practical energy-efficient direct-contact ultrasonic fabric drying applications compared with the Gaussian model.

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Influence of Different Hot Air Drying Temperatures on Drying Kinetics, Shrinkage, and Colour of Persimmon Slices

Foods ◽

10.3390/foods9010101 ◽

2020 ◽

Vol 9 (1) ◽

pp. 101 ◽

Cited By ~ 2

Author(s):

Senadeera ◽

Adiletta ◽

Önal ◽

Di Matteo ◽

Russo

Keyword(s):

Moisture Content ◽

Quadratic Model ◽

Drying Process ◽

Air Velocity ◽

Hot Air Drying ◽

Drying Time ◽

Air Drying ◽

Drying Characteristics ◽

Drying Temperature ◽

Hot Air

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.

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Effect of Air Velocity and Temperature on the Drying Kinetics of Drumstick Leaves (Moringa Oleifera)

International Journal of Food Engineering ◽

10.1515/1556-3758.1986 ◽

2012 ◽

Vol 8 (4) ◽

Cited By ~ 9

Author(s):

Monica Premi ◽

Harish Sharma ◽

Ashutosh Upadhyay

Keyword(s):

Experimental Data ◽

Activation Energy ◽

Moringa Oleifera ◽

Moisture Diffusivity ◽

Drying Kinetics ◽

Drying Rate ◽

Air Velocity ◽

Drying Time ◽

Effective Moisture ◽

Kinetics Of

Abstract The present study examines the effect of air velocity on drying kinetics of the drumstick leaves in a forced convective dryer. The drumstick leaves were dried in the temperature range of 50–800 C, at different air velocity (Dv) of 0.5 and 1.3 m/s. The results indicated that drying temperature and air velocity are the factors in controlling the drying rate. Experimental data obtained for the samples for color, drying rate and drying time proved that air velocity of 1.3 m/s yielded the product superior in terms of both quality and energy efficiency as compared to the samples at 0.5 m/s. Activation energy for drumstick leaves dried with air velocity, 0.5 and 1.3 m/s was 12.50 and 32.74 kJ/mol respectively. The activation energy relates similarly with the effective moisture diffusivity which also increased with increase in air velocity and temperature.

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Thermodynamic Evaluation of the Forced Convective Hybrid-Solar Dryer during Drying Process of Rosemary (Rosmarinus officinalis L.) Leaves

Energies ◽

10.3390/en14185835 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5835

Author(s):

Hamed Karami ◽

Mohammad Kaveh ◽

Iman Golpour ◽

Esmail Khalife ◽

Robert Rusinek ◽

...

Keyword(s):

Energy Utilization ◽

Exergy Loss ◽

Thermodynamic Evaluation ◽

Drying Process ◽

Operational Parameters ◽

Air Velocity ◽

Solar Dryer ◽

Energy And Exergy ◽

Four Levels ◽

Rosmarinus Officinalis L

This study aimed to examine the energy and exergy indices of the rosemary drying process in a hybrid-solar dryer (HSD) and the effects of air-drying parameters on these thermodynamic indices. Drying experiments were carried out at four levels of air temperature (40, 50, 60, and 70 ∘C) and three levels of air velocity (1, 1.5, and 2 m/s). Energy and exergy were calculated by application of the first and second laws of thermodynamics. Based on the principal laws, energy efficiency, exergy losses, and exergetic improvement potential rate, were evaluated. The results showed that the energy utilization ratio (EUR) ranged from 0.246 to 0.502, and energy utilization (EU) ranged from 0.017 to 0.060 (kJ/s). Exergy loss and efficiency varied from 0.009 to 0.028 (kJ/s) and from 35.08% to 78.5%, respectively, and increased with increased temperature and air velocity. It was found that the exergy loss rate was affected by temperature and air velocity because the overall heat transfer coefficient was different under these conditions. By comparison, with increasing temperature and air velocity, the exergy efficiency increased. Because most energy is used to evaporate moisture, this behavior may be explained by improved energy utilization. The drying chamber sustainability index ranged from 0.0129 to 0.0293. This study provides insights into the optimization process of drying operations and operational parameters in solar hybrid dryers that reduce energy losses and consumption.

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