Energy of activation, instantaneous energy consumption, and coupled heat and mass transfer modeling in drying of sorghum grains

2021 ◽  
Vol 210 ◽  
pp. 181-192
Author(s):  
Hugo Perazzini ◽  
Alice Leonel ◽  
Maisa T.B. Perazzini
2020 ◽  
Vol 6 (2) ◽  
pp. 81-87
Author(s):  
Zhanna Petrova ◽  
◽  
Kateryna Samoilenko ◽  
Vitaly Vishnevsky

Red beetroot is the main raw material which has a high content of betanine with antioxidant properties. An important emphasis in the processing of antioxidant raw materials by drying is to reduce energy consumption for the dehydration process, the maximum preservation of biologically active substances, and to reduce the cost of the final product. Drying is a complex and energy-intensive process. Therefore, to optimize energy consumption during drying and selection of rational modes of dehydration, it is necessary to apply the calculated analysis of heat and mass transfer on the basis of adequate mathematical models. Calculated and experimental results are compared. In general, the comparison of the results of numerical modeling of convection drying processes of the red beetroot sample with the experimental results showed their rather satisfactory qualitative agreement. The calculation model can be used to approximate the characteristics of the drying process of red beetroot, in particular the time required for drying. The obtained results of calorimetric studies allow stating that with correctly selected compositions, not only the components of native raw materials are stabilized, but also the drying process is intensified with the reduction of energy consumption to process.


2020 ◽  
Vol 20 (7) ◽  
pp. 2858-2874
Author(s):  
Mostafa Abd El-Rady Abu-Zeid ◽  
Xiaolong Lu ◽  
Shaozhe Zhang

Abstract The low flux and high energy consumption problems of the conventional three-stage air-gap membrane distillation (AG-AG-AG)MD system caused by the low temperature difference between hot and cold feed at both sides of the membrane and high boundary layer thickness were solved successfully by replacing one of the three stages of air gaps by a water gap. The novel three-stage air-gap–water-gap membrane distillation (AG-AG-WG)MD system reduced energy consumption and increased flux due to efficient internal heat recycling by virtue of a water-gap module. Heat and mass transfer in novel and conventional three-stage systems were analyzed theoretically. Under a feed temperature of 45 °C, flow rate of 20 l/h, cooling temperature of 20 °C, and concentration of 340 ppm, the (AG-AG-WG)MD promoted flux by 17.59% and 211.69%, and gained output ratio (GOR) by 60.57% and 204.33% compared with two-stage (AG-WG)MD and one-stage AGMD, respectively. This work demonstrated the important role of a water gap in changing the heat and mass transfer where convection heat transfer across the water gap is faster by 24.17 times than conduction heat transfer through the air gap. The increase in flux and GOR economized the heating energy and decreased waste heat input into the system. Additionally, the number of MD stages could increase the achieving of a high flux with operation stability.


2009 ◽  
Vol 27 (10) ◽  
pp. 1051-1059 ◽  
Author(s):  
Y. L. Lin ◽  
S. J. Li ◽  
Y. Zhu ◽  
G. Bingol ◽  
Z. Pan ◽  
...  

2016 ◽  
Vol 171 ◽  
pp. 1-13 ◽  
Author(s):  
L. Lecoq ◽  
D. Flick ◽  
E. Derens ◽  
H.M. Hoang ◽  
O. Laguerre

2018 ◽  
Vol 556 ◽  
pp. 248-262 ◽  
Author(s):  
Amin Engarnevis ◽  
Ryan Huizing ◽  
Sheldon Green ◽  
Steven Rogak

2013 ◽  
Vol 5 (2) ◽  
pp. 57-76 ◽  
Author(s):  
J. F. Cepeda ◽  
C. L. Weller ◽  
M. Negahban ◽  
J. Subbiah ◽  
H. Thippareddi

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