scholarly journals Drying characteristics and kinetics of fluidized bed dried potato

2008 ◽  
Vol 19 (2) ◽  
pp. 127 ◽  
Author(s):  
S.B. BAKAL ◽  
K.H. GEDAM ◽  
G.P. SHARMA

In developed countries, more than 50% potatoes are consumed as processed products. As drying is the vital phenomenon in processing, it is necessary to investigate the drying characteristics and its kinetics. In this experimental study, drying kinetics of Potato in two different shape of cuboidal & cylindrical with three aspect ratio was investigated as a function of drying conditions. Experiments were conducted using air temperatures of 50, 60 and 70 ºC, at velocity of 7 ms-1. The experimental moisture data were fitted to Page and simple models available in the literature, and a good agreement was observed. The Page model gave better fit than simple model. In the ranges covered, the values of the effective moisture diffusivity, Deff were obtained between 2.278 × 10-9 to 3.314 × 10-8 m2s-1 from the Fick's diffusion model. Using Deff, the value of activation energy (Ea) was determined assuming the Arrhenius-type temperature relationship.

2022 ◽  
Vol 52 (1) ◽  
pp. 43-48
Author(s):  
Ibrahim Doymaz

The effect of different infrared (IR) powers on drying of orange slices was investigated in infrared dryer. The orange slices dried at 62, 74 and 88 W infrared powers and constant slice thickness of 6 mm. Results showed that drying, colour and rehydration characteristics of orange slices were greatly influenced by infrared power. The drying data were fitted with five mathematical models available in the literature. Based on the statistical tests applied to make an assessment, the model of Midilli and Kucuk was found to satisfactorily explain drying kinetics of orange slices for all drying conditions. The Fick’s diffusion model was used to calculate the effective moisture diffusivity (Deff) of orange slices. The value of Deff varied from 1.59×10-10 to 2.49×10-10 m2/s. It was found that the effective moisture diffusivities increased with increasing IR power. Activation energy was estimated by a modified Arrhenius type equation as 2.11 kW/kg. As the infrared power increased, the rehydration ratio was found to be reduced. Furthermore, with increase of infrared power, the values of a and DE increased, whereas the values of L, b and C decreased.


Author(s):  
Monica Premi ◽  
Harish Sharma ◽  
Ashutosh Upadhyay

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.


2015 ◽  
Vol 11 (6) ◽  
pp. 851-860 ◽  
Author(s):  
Man Zhou ◽  
Zhouyi Xiong ◽  
Jie Cai ◽  
Hanguo Xiong

Abstract Convective air drying characteristics and qualities of non-fried instant noodles at five temperatures from 80 to 120°C and velocities of 1.0, 2.0 and 3.0 m/s were investigated. Different mathematical models were fitted to study the drying behaviors and the Logarithmic model was the most adequate in describing the drying tests. Results showed that the drying process occurred in a falling rate periods and the effective moisture diffusivity increased with temperature and velocity, ranging from 4.41×10−8 to 1.75×10−7 m2/s with an activation energy of 16.73 kJ/mol. The rehydration attributes changed with both velocity and temperature. Increasing temperature and velocity decreased hardness, increased cohesiveness and resilience generally while had no impact on springiness. Drying temperature greatly influenced the color of noodles, whereas velocity displayed no significant effect. Microstructural analysis indicated that noodle presented hollow and porous structure with numerous and small voids, which might partly explain their distinct behaviors.


Author(s):  
Samuel Enahoro Agarry

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.


2019 ◽  
Vol 65 (No. 4) ◽  
pp. 137-144
Author(s):  
Annisa Kusumaningrum ◽  
Dwi Joko Prasetyo ◽  
Ervika Rahayu Novita Herawati ◽  
Asep Nurhikmat

An oven drying method was used to dry traditional Indonesian crackers, popularly known as kerupuk, applying drying temperatures of 50, 60 and 70°C and three different flavours, i.e., garlic, chili and seaweed. Newton, Page, Two terms, Midilli, Logarithmic and Henderson &amp; Pabis mathematical models were used to fit the best model while the standard error of estimate (SSE), root mean square error (RMSE) and coefficient of correlation (r) were chosen as the criteria to determine the equation of the best fit drying model. The Midilli model was the best fit for all the kerupuk flavours. The effective moisture diffusivity was in the range of 1.0413 × 10<sup>–10</sup>–1.6363 × 10<sup>–10</sup> m<sup>2</sup>·s<sup>–1</sup> for the garlic flavour, 1.0007 × 10<sup>–10</sup>–1.5619 × 10<sup>–10</sup> m<sup>2</sup>·s<sup>–1</sup> for the chili flavour and from 1.0000 × 10<sup>–10</sup> to <br /> 1.6228 × 10<sup>–10</sup> m<sup>2</sup>·s<sup>–1</sup> for the seaweed flavour. The activation energy of the garlic flavour, chili flavour and seaweed flavour kerupuk are 20.64, 20.64 and 22.57 kJ·mol<sup>–1</sup>, respectively. Furthermore, in the present study, the physical properties, i.e., the colour and hardness of the kerupuk crackers after the drying process was investigated.


2016 ◽  
Vol 369 ◽  
pp. 119-124
Author(s):  
E.M.A. Pereira ◽  
J.V. Silva ◽  
J.P.S. Santos ◽  
T.H.F. Andrade ◽  
A.G. Barbosa de Lima

This work aims to conduct an experimental study of the drying kinetics of castor bean fruits (Ricinuscommunis L., “BRS Energia” variety). Experiments were conducted using an oven at air temperatures 50 and 70°C and air relative humidity values 16.34 and 6.24%, respectively. The castor bean fruits were considered as a triaxial spheroid. The experimental moisture content data as a function of time were fitted to different lumped models (namely Henderson and Pabis, Page, Midilli and two-term exponential models) available in the literature.The values of the effective moisture diffusivity were obtained from the Fick's diffusion model. Results shows that the two-term drying model could adequately describe the thin layer drying behavior of castor bean fruit, and that the effective moisture diffusivity increases with increasing drying air temperature.


Author(s):  
Smail Meziane ◽  
Naima Mesbahi

Abstract The thin layer drying of olive pomace was experimentally studied in a laboratory convective dryer. Drying experiments were performed under five air temperatures of 60, 70, 80 and 90ºC, two air velocities of 1.0 and 1.8 m s-1 and three thickness of thin layer of 6, 9 and 12 mm. The results show that the drying time decreased with increased in drying temperature and air velocity but increased with the decreasing of thin layer thickness of olive pomace. Over the experimental range studied, the values of effective moisture diffusivity and activation energy ranged from 1.25 • 10-9 to 6.30 • 10-9 m2 s-1 and 26.30 to 37.63 kJ mol-1, respectively. The dependence of these parameters on thickness of thin layer, and temperature and velocity of drying air has been investigated.


2019 ◽  
Vol 49 (4) ◽  
pp. 213-218
Author(s):  
Seda Kayran ◽  
Íbrahim Doymaz

Effect of infrared powers (62, 74, 88, 104 and 125 W) on drying kinetics of apricot pomace was investigated. It is observed that drying characteristics of apricot pomace were greatly influenced by infrared power. Henderson and Pabis model was investigated for describing thin-layer drying of apricot pomace. The model because of the high coefficient of determination (R2) as well as the lowest reduced chi-square (c2) and root mean square error (RMSE) values adequately described the experimental data of apple pomace drying. Effective moisture diffusivity (Deff) values were increased by increasing infrared power and changed between 1.67×10-9 and 6.03×10-9 m2/s. Activation energy was estimated by a modified Arrhenius type equation and found to be 2.32 kW/kg. The colour results were affected by drying conditions.


2016 ◽  
Vol 22 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Monika Lutovska ◽  
Vangelce Mitrevski ◽  
Ivan Pavkov ◽  
Vladimir Mijakovski ◽  
Milivoj Radojcin

In this study, a thin - layer drying of pear slices as a function of drying conditions were examined. The experimental data set of thin - layer drying kinetics at five drying air temperatures 30, 40, 50, 60 and 70?C, and three drying air velocities 1, 1.5 and 2 m s-1 were obtained on the experimental setup, designed to imitate industrial convective dryer. Five well known thin - layer drying models from scientific literature were used to approximate the experimental data in terms of moisture ratio. In order to find which model gives the best results, numerical experiments were made. For each model and data set, the statistical performance index, (?), and chi-squared, (?2), value were calculated and models were ranked afterwards. The performed statistical analysis shows that the model of Midilli gives the best statistical results. Because the effect of drying air temperature and drying air velocity on the empirical parameters was not included in the base Midilli model, in this study the generalized form of this model was developed. With this model, the drying kinetic data of pear slices can be approximated with high accuracy. The effective moisture diffusivity was determined by using Fick?s second laws. The obtained values of the effective moisture diffusivity, (Deff), during drying ranged between 6.49 x 10-9 and 3.29 x 10-8 m2 s-1, while the values of activation energy (E0) varied between 28.15 to 30.51 kJ mol-1.


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