scholarly journals Evaluate the drying of food waste using cabinet dryer

Author(s):  
Ahmad khaloahmadi ◽  
Ali Mohammad Borghei ◽  
Omid Reza roustpoor

Abstract Purpose In order to reduce leachate from food waste; a food waste dryer with a conventional tray was built, and drying of food waste was investigated. Methods Power of 2.7 kW was used as the heat source, and a centrifugal fan with an air volume of 1300 m3/h, 2800 rpm, and 110 pa was used. The experiments were performed at three temperatures of 50, 60, and 70°C and three air velocities of 1, 1.5, and 2 m/s with a thickness of 3 cm. A conventional tray was used for drying. The Drying kinetics, effective moisture diffusivity, activation energy, and dryer energy consumption during drying of food waste were obtained. Result The minimum drying process was occurred in temperature of 70°C and air velocity of 2 m/s at the 120 min, and the maximum drying process was happened in temperature of 50°C and air velocity of 1 m/s at the 890 min. The energy consumption of drying process had the lowest value at 70°C of temperature and 2 m/s of inlet air velocity. The highest energy consumption value was related to temperature of 50°C and velocity of 1m/s. Effective moisture diffusivity of waste food during the drying process was in the range of 2.74×10− 9-3.65×10− 8 m2/s. The values of energy of activation were determined between 21.596 and 64 KJ/mol. Conclusion Cabinet dryer with a conventional tray can be used for drying food waste in the shortest time with low energy consumption.

Author(s):  
J. Isa ◽  
O. I. Majasan ◽  
K. A. Jimoh

During milling of cereal grains, bran which is separated from the starchy endosperm of the grain is a major by-product. In this study, milled sorghum residue was dried in a cabinet dryer under different conditions (temperature and air velocity). The obtained drying data were fitted into ten existing mathematical models and obtained the best model while, the effective moisture diffusivity and activation energy of the drying process was determined using Arrhenius type approach. The result shows that the initial moisture content obtained for the sorghum residue using standard oven drying method were 41.28 ± 0.33%, 49.52 ± 0.63 % and 47.06 ± 0.42 % on wet basis for the wet residue of variety A, B and C, respectively, at equilibrium point, the final moisture content of about 12.93 ± 0.14 – 14.31± 0.07 as temperature ranges from 40 oC to 70 oC and air velocity ranges from 0.8 m/s to 1.2 m/s. During the drying process, the drying rate falls more rapidly as it was initially high as a result of more moisture in the sorghum residue and the drying rate decreases slowly until reaching the reduced moisture content. The obtained values of effective moisture diffusivity (Deff) ranges between 9.89 x 10-10 and 22.21 x 10-10 m2/s, 9.45 x 10-10 and 20.62 x 10-10 m2/s and 8.56 x 10-10 and 20.76 x 10-10 m2/s for variety A, B and C, respectively. However, the result of the modelling shows that the drying characteristics of variety A and B of the sorghum residue can be predicted using Midilli et al. model while the drying behaviour of Variety C can be predicted using Hii et al. model.


2020 ◽  
Vol 399 ◽  
pp. 173-182
Author(s):  
Raí M. de Oliveira ◽  
Keyse S. Andrade ◽  
Manoel Marcelo Prado ◽  
L.G. Marques

Drying characteristics of watermelon seeds using infrared (IR) heating combined to non-heated air flow were determined varying the IR source temperature and air velocity. The effects of the process variables on the effective moisture diffusivity (Deff) and specific energy consumption (SEC) were also evaluated. Experiments in the hybrid dryer were conducted with seeds arranged in a single layer and exposed to three IR temperatures levels (45, 65 and 85 W/m2) and three air velocities levels (0.4, 0.8 and 1.2 m/s) at 25°C. The effective moisture diffusivity was estimated using Fick’s diffusion model assuming negligible shrinkage and surface moisture in equilibrium with the surrounding air. Deff-values ranged from 0.62 x 10-10 to 1.83 x 10-10 m2/s, while SEC-valued varied from 29.91 to 73.16 kWh/g. Statistical analysis carried out on the experimental data indicated that the effective moisture diffusivity and specific energy consumption were significantly influenced only by the IR source temperature, which had a positive linear effect on Deff and a negative linear effect on SEC. Maximum effective diffusivity and minimum energy consumption values in hybrid drying of watermelon seeds were obtained with the use of the highest IR temperature and lowest air velocity.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 284
Author(s):  
Ebrahim Taghinezhad ◽  
Mohammad Kaveh ◽  
Antoni Szumny

Drying can prolong the shelf life of a product by reducing microbial activities while facilitating its transportation and storage by decreasing the product weight and volume. The quality factors of the drying process are among the important issues in the drying of food and agricultural products. In this study, the effects of several independent variables such as the temperature of the drying air (50, 60, and 70 °C) and the thickness of the samples (2, 4, and 6 mm) were studied on the response variables including the quality indices (color difference and shrinkage) and drying factors (drying time, effective moisture diffusivity coefficient, specific energy consumption (SEC), energy efficiency and dryer efficiency) of the turnip slices dried by a hybrid convective-infrared (HCIR) dryer. Before drying, the samples were treated by three pretreatments: microwave (360 W for 2.5 min), ultrasonic (at 30 °C for 10 min) and blanching (at 90 °C for 2 min). The statistical analyses of the data and optimization of the drying process were achieved by the response surface method (RSM) and the response variables were predicted by the adaptive neuro-fuzzy inference system (ANFIS) model. The results indicated that an increase in the dryer temperature and a decline in the thickness of the sample can enhance the evaporation rate of the samples which will decrease the drying time (40–20 min), SEC (from 168.98 to 21.57 MJ/kg), color difference (from 50.59 to 15.38) and shrinkage (from 67.84% to 24.28%) while increasing the effective moisture diffusivity coefficient (from 1.007 × 10−9 to 8.11 × 10−9 m2/s), energy efficiency (from 0.89% to 15.23%) and dryer efficiency (from 2.11% to 21.2%). Compared to ultrasonic and blanching, microwave pretreatment increased the energy and drying efficiency; while the variations in the color and shrinkage were the lowest in the ultrasonic pretreatment. The optimal condition involved the temperature of 70 °C and sample thickness of 2 mm with the desirability above 0.89. The ANFIS model also managed to predict the response variables with R2 > 0.96.


Author(s):  
Magesh Ganesh Pillai ◽  
Iyyasamy Regupathi ◽  
Lima Rose Miranda ◽  
Thanapalan Murugesan

The drying characteristics of plaster of paris (POP) under microwave conditions at different microwave power input, initial moisture content, sample thickness and drying time were studied. Further the experimental data on moisture ratio of POP for different operating conditions were obtained and calculations were made using nine basic drying model equations. The appropriate model with modified constants and coefficients to represent the drying kinetics of POP was found through the analysis of the statistical analysis. The effective moisture diffusivity of the drying process was also computed for different experimental conditions and a relationship between the drying rate constant and the effective moisture diffusivity was obtained. The energy consumption for microwave drying of plaster of paris at different experimental conditions were also computed.


DYNA ◽  
2017 ◽  
Vol 84 (202) ◽  
pp. 112-119 ◽  
Author(s):  
Diana Carolina Potosí-Calvache ◽  
Pedro Vanegas-Mahecha ◽  
Hugo Alexander Martinez Correa

Se estudia la influencia de la temperatura y la velocidad del aire en el secado convectivo de zapallo (Cucúrbita moschata- UNAPAL Abanico 75), por medio de la cinética de secado y los cambios en el contenido de compuestos fenólicos y carotenos totales. Se empleó la metodología de superficie de respuesta para optimizar las condiciones de operación en el secado de pulpa de zapallo. Los factores estudiados fueron, temperatura de secado (45 – 65 °C) y velocidad de aire (4 y 7 m.s-1). Las condiciones óptimas de secado de pulpa de zapallo fueron; 55 °C y 7m. s-1, para la temperatura y velocidad de aire respectivamente. El tiempo de secado fue 390 min aproximadamente. La harina obtenida presento humedad 6.34 ± 0.10 % (bh), carotenoides totales; 141.5 ± 1.32 mg/100 g de muestra, fenoles totales; 72.9 ± 2.2 mg /100 g de muestra.


2016 ◽  
Vol 62 (No. 1) ◽  
pp. 15-23 ◽  
Author(s):  
H. Samimi Akhijani ◽  
A. Arabhosseini ◽  
M.H. Kianmehr

Mathematical modelling and effective moisture diffusivity of tomato (Lycopersicon esculentum) was studied during hot air solar drying. An experimental solar dryer with a swivel collector was used for experiments. The collector followed the solar radiation using a precious sensor. Drying experiments were performed in a thin layer hot air drying at slice thicknesses of 3, 5 and 7 mm and air velocities of 0.5, 1 and 2 m/s. The experimental data were fitted to different mathematical moisture ratio models and the Page model was selected as the best model according to correlation coefficient R<sup>2</sup>, chi-square &chi;<sup>2</sup> and root mean square error (RMSE) parameters. The maximum values of moisture diffusivity was&nbsp;6.98 &times; 10<sup>&ndash;9</sup> m<sup>2</sup>/s at air velocity of 2 m/s and slice thickness of 7 mm while the minimum value of the moisture diffusivity was 1.58 &times; 10<sup>&ndash;9</sup> m<sup>2</sup>/s at air velocity of 0.5 m/s and slice thickness of 3 mm.


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