scholarly journals Drying kinetics and thermodynamic analysis of tomato in a tunnel dryer

2021 ◽  
Vol 34 (03) ◽  
pp. 31-45
Author(s):  
Apolinar Picado ◽  
Steve Alfaro ◽  
Rafael Gamero
Keyword(s):  
Thermodynamic Analysis ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Air Velocity ◽  
Available Energy ◽  
Tunnel Dryer ◽  
Maximum Value ◽  
Rate Period ◽  
Drying Curves ◽  
Kinetics And Thermodynamic

In this study, drying kinetics and thermodynamic analysis of tomato were conducted in a tunnel dryer. Drying experiments were performed at three temperatures (100, 115, and 130 °C) and an air velocity of 1.45 m/s. From the drying curves, only a falling rate period was observed. Under these conditions, a characteristic drying curve was determined. It is observed that at the 40 minutes of the drying process, the outlet gas enthalpy achieved a maximum value that is very close to the inlet value and remained constant until the end of the process. Entropy exhibited similar behaviour to enthalpy. The maximum value of the exergy efficiency curve corresponds to the maximum value observed within the drying rate curves. This maximum value represents the stage when the available energy is efficiently used in moisture removal. As the drying rate decreases the available energy is started to be less employed.

scholarly journals Determining of moisture diffusivity and activation energy in drying of apricots

2009 ◽  
Vol 55 (No. 3) ◽  
pp. 114-120 ◽  
Author(s):  
E. Mirzaee ◽  
S. Rafiee ◽  
A. Keyhani ◽  
Z. Emam-Djomeh
Keyword(s):  
Activation Energy ◽  
Moisture Diffusivity ◽  
Second Law ◽  
Drying Rate ◽  
Air Velocity ◽  
Air Temperatures ◽  
Rate Period ◽  
Drying Curves

In this study, Fick’s second law was used as a major equation to calculate the moisture diffusivity for apricot fruit with some simplification. Drying experiments were carried out at the air temperatures of 40, 50, 60, 70, and 80°C and the drying air velocity of 1, 1.5 and 2 m/s. The experimental drying curves showed only a falling drying rate period. The calculated value of the moisture diffusivity varied from 1.7 × 10<sup>–10</sup> to 1.15 × 10<sup>–9</sup> m<sup>2</sup>/s for apricot fruit, and the value of activation energy ranged from 29.35 to 33.78 kJ/mol at different velocities of air.

The Influence of Stainless Steel Mesh Porous Burner on Drying Kinetics of Nile Tilapia

2019 ◽  
Vol 805 ◽  
pp. 116-121
Author(s):  
Pathiwat Waramit ◽  
Apinunt Namkhat ◽  
Umphisak Teeboonma
Keyword(s):  
Stainless Steel ◽  
Heat Source ◽  
Nile Tilapia ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Air Velocity ◽  
Stainless Steel Mesh ◽  
Steel Mesh ◽  
Porous Burner ◽  
Kinetics Of

This paper studied the influence of porous burner effect on drying kinetics of Nile tilapia drying using stainless steel mesh porous burner as heat source. Drying kinetics was analyzed by determination of drying rate (DR), drying specific energy consumption (SEC) and dryer thermal efficiency (). In this study, the stainless steel mesh was used as porous media with porosity of 10, 20 and 50 pore per inch (PPI), drying air velocity of 0.5, 1.0 and 1.5 m/s, and drying temperature of 50, 60 and 70 °C, respectively. The results were found that the application of porous burner as heat source can improve the drying kinetics. It was found, at the porosity of 50 PPI, the drying temperature of 70 °C and the air velocity of 1.5 m/s, the moisture ratio of the drying was decreased rapidly, the highest drying rate was found to be 150 g (water evap.)/hr., the lowest drying energy consumption was found to be146.75 MJ/kg, and the thermal efficiency of the dryer was found to increase by 17.79% and the CO and NOx concentration in case of applying porous burner as heat source is lower than without porous burner.

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

2012 ◽  
Vol 8 (4) ◽  
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.

scholarly journals Drying kinetics of mango fruit using tray and oven dryer

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.

scholarly journals Convective air drying of brown seaweed Bifurcaria bifurcata in thin layer configuration

2018 ◽  
Author(s):  
Ramón Moreira ◽  
Santiago Arufe-Vilas ◽  
Jorge Sineiro ◽  
Francisco Chenlo
Keyword(s):  
Brown Seaweed ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Transfer Coefficients ◽  
Air Drying ◽  
Bifurcaria Bifurcata ◽  
Kinetics Modelling ◽  
Effective Coefficients ◽  
Rate Period ◽  
Critical Moisture

Air drying kinetics of Bifurcaria bifurcata brown seaweed at 35, 50, 60 and 75°C were determined. Experimental drying data were modelled using two-parameter Page model (n, k). Page parameter n was constant (1.28) at tested temperatures, but k increased significantly with drying temperature from 35 to 60ºC and was invariant at higher temperatures (up to 75ºC). Drying experiments allowed the determination of the critical moisture content of seaweed (1.6 ± 0.2 kg water (kg d.b.)−1). Mass transfer coefficients during constant drying rate period and effective coefficients of water diffusion during falling drying rate period were evaluated, assuming cyclindrical geometry and considering volumetric shrinkage. Keywords: algae, diffusivity, drying kinetics, modelling, shrinkage  

Study on the Drying Mechanism and Dynamics of Palygorskite

2011 ◽  
Vol 422 ◽  
pp. 501-504
Author(s):  
Jiang Quan Ma ◽  
Qing Ling Lu ◽  
Jun Hao Xia ◽  
Xiao Bin Gan ◽  
Chao Yao
Keyword(s):  
Activation Energy ◽  
Environmental Protection ◽  
Drying Kinetics ◽  
Diffusion Activation Energy ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Curves ◽  
Kinetics Of ◽  
Diffusion Activation

Palygorskite had large applications in chemical, environmental protection, medicine processes and so on. However, since the mineral limitations of natural palygorskite, both improving its quality and meeting the need of industry, palygorskite usually needs to be activated before using it. The influences of activation during the drying process were studied, as well as the drying kinetics of the non-activated of palygorskite. The results showed that the drying rate of palygorskite increased at first, and then came to a constant value, and kept that value for some time. After that, drying rate decreased with time going. Compared with drying curves of the non activated palygorskite, the samples made some changes after activation. The drying process of non activated palygorskite could be described as the equation of MR=exp(-ktn). The diffusion activation energy (E) of non activated palygorskite was equal to 17.14kJ•mol-1, former factors of Arrhenius was equal to 4.19×10-5 m2•s-1.

Study on the Drying Mechanism and Dynamics of Palygorskite

2013 ◽  
Vol 706-708 ◽  
pp. 456-459
Author(s):  
Shi Long Wang ◽  
Li Na Wang
Keyword(s):  
Activation Energy ◽  
Environmental Protection ◽  
Drying Kinetics ◽  
Diffusion Activation Energy ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Curves ◽  
Kinetics Of ◽  
Diffusion Activation

Palygorskite had large applications in chemical, environmental protection, medicine processes and so on. However, since the mineral limitations of natural palygorskite, both improving its quality and meeting the need of industry, palygorskite usually needs to be activated before using it. The influences of activation during the drying process were studied, as well as the drying kinetics of the non-activated of palygorskite. The results showed that the drying rate of palygorskite increased at first，and then came to a constant value, and kept that value for some time. After that, drying rate decreased with time going. Compared with drying curves of the non activated palygorskite, the samples made some changes after activation. The drying process of non activated palygorskite could be described as the equation of MR=exp(-ktn).The diffusion activation energy (E) of non activated palygorskite was equal to 17.14kJ.mol-1, former factors of Arrhenius was equal to 4.19×10-5 m2.s-1.

Drying Kinetics of Malaysian Paddy (Group D Particles) in Spouted Bed Dryer

2006 ◽  
Vol 2 (3) ◽  
Author(s):  
Pin Pin Ng ◽  
Chung Lim Law ◽  
Siti Masrinda Tasirin
Keyword(s):  
Draft Tube ◽  
Air Flow ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Spouted Bed ◽  
Bed Height ◽  
Internal Structures ◽  
Drying Curves ◽  
Group D ◽  
Kinetics Of

Spouted bed is suitable for drying of coarse particles which are Group D of Geldart’s particle classification. Malaysian grown paddy was used as a Group D sample in a lab-scale spouted bed dryer. Drying was carried out in two different internal structures of the dryer, namely with or without the installation of a draft tube, and at several drying temperatures, air flow rates as well as bed heights. Spouted bed drying kinetics of paddy presented in drying curves showed only induction and falling rate periods, without constant drying rate period. The highest drying rate was achieved when paddy was dried without draft tube at low bed height, high drying temperature and air flow rate.

scholarly journals Mathematical modeling of moisture evaporation in co-current foam spray drying

2018 ◽  
Author(s):  
Maciej Jaskulski ◽  
Artur Lewandowski ◽  
Ireneusz Zbiciński
Keyword(s):  
Spray Drying ◽  
Particle Morphology ◽  
Moisture Diffusion ◽  
Drying Rate ◽  
Rate Period ◽  
Perfect Mixing ◽  
Drying Models ◽  
Drying Curves ◽  
Foam Drying ◽  
Droplet Drying

Two models of foam drying are presented in the paper: single droplet drying and perfect mixing of phases spray drying models to describe mechanism of drying of droplet containing bubble. Analysis of drying curves shows that in constant drying rate period and in the falling drying rate period, evaporation rate decreases due to particle shrinkage and increasing of resistance of moisture diffusion inside the solid crust. Increase of gas pressure in the bubble might cause particle breakage. Slight differences between theoretical and experimental results caused by disregarding broken particles in the simulations proves accuracy of the developed model. Keywords: spray drying, modeling, foamed materials, particle morphology 

scholarly journals Monoammonium phosphate (MAP) fertilizer drying kinetics in tray dryer

2018 ◽  
Vol 24 (1) ◽  
pp. 77-83 ◽  
Author(s):  
André Covello ◽  
Marcello Nitz
Keyword(s):  
Phosphate Fertilizer ◽  
Drying Rate ◽  
Air Velocity ◽  
Temperature Dependent ◽  
Monoammonium Phosphate ◽  
Whole Process ◽  
Drying Kinetic ◽  
Drying Behaviour ◽  
Drying Curves ◽  
Ratio Reduction

The drying behaviour of monoammonium phosphate fertilizer was examined in a static tray dryer, establishing kinetic parameters that may be used to improve the design of dryers. Drying temperatures ranged from 80 to 95?C, and surface air velocity was 0.50 m/s. The material was previously separated into two particle sizes, between 1.40 and 2.38 mm mean diameter. Drying curves were analysed qualitatively and seven empirical kinetic thin-layer models were fitted. The drying kinetic showed to be temperature-dependent: a moisture ratio reduction of 90% was achieved twice as fast at 95?C than at 80?C. On the other hand, particle size did not exert significant influence on the drying rate. The results showed a decreasing drying rate throughout the whole process. All studied models adjusted well to the experimental data: R2 values were all above 0.999. The two-term model generated the lowest RMSE and ?2 values, between 0.00621 and 0.010743 and between 0.000044 and 0.000115, respectively.

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