KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Subject: search.filters.subject.Drying kinetic

Search Results

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Drying kinetics and quality of cissus quadrangularis linn. Dried by convective hot air
    (2020-09-01)
    Thanimkarn, Setthawat
    ;
    Cheevitsopon, Ekkapong
    ;
    Jongyingcharoen, Jiraporn Sripinyowanich
    This research aimed to determine a suitable drying model of convective hot air drying of Cissus quadrangularis Linn. (CQ), determine the effective moisture diffusivity of the drying process and the activation energy of CQ, and investigate the effects of drying temperatures on energy consumption and quality of dried CQ. Experiments were performed at 40°C, 60°C, 80°C, and 100°C drying temperature and 1 m s<sup>-1</sup> air velocity to dry CQ from 10 g water/g dry matter to 0.1 g water/g dry matter. The generalized linear-plus-exponential-type model has been used to fit the drying kinetics of CQ and demonstrates, among others, the moisture data of hot air drying of CQ at the validation temperature of 50°C satisfactorily with an R<sup>2</sup> of 0.9977. The effective moisture diffusivity was in the range of 0.7302-9.1281 ×10<sup>-9</sup> m<sup>2</sup> s<sup>-1</sup>, a positive relationship was observed between this parameter and drying temperature. The activation energy of CQ was 39.78 kJ mol<sup>-1</sup>. The lowest energy consumption of 3.40 kWh was required when the highest drying temperature of 100°C was applied. The quality was well preserved when CQ was dried at a lower drying temperature. Drying at 60°C produced dried CQ with the lowest total color difference (16.76), shrinkage percentage (88.47%), and bulk density (0.1817 g cm<sup>-3</sup>) as well as the highest total phenolic (1062 mg GAE/100 g dry matter) and quercetin contents (0.955 mg/100 g dry matter).
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Drying characteristics of peppercorns in a rectangular fluidized-bed with triangular wavy walls
    (2011-11-01)
    Promvonge, Pongjet
    ;
    Boonloi, Amnart
    ;
    Pimsarn, Monsak
    ;
    Thianpong, Chinaruk
    An experimental study on drying kinetics of peppercorns has been conducted in two different drying fluidized-bed configurations: rectangular fluidized-bed (RFB) and rectangular fluidized-bed with wavy walls (RFBW). In the RFBW, two opposite triangular wavy walls with three blockage ratios (e/H) are formed to produce vortex/swirl flows leading to stronger turbulence and longer residence time of the flow in the bed. For each bed, three inlet hot airs (T<inf>in</inf>) at 60°C, 80°C and 100°C and two superficial air velocity, U* of 1.2 and 2.0 (U*=U/U<inf>mf</inf>) are introduced. The experimental results reveal that the air temperature and air velocity show significant effects on the drying rate of both beds, especially at T<inf>in</inf>=100°C and U*=2.0. The RFBW performs much better than the RFB due to shorter drying time. The average drying time of the RFBW with e/H=0.3125, 0.3750 and 0.4375 is, respectively, around 29%, 36% and 43% less than that of the RFB. In addition, three mathematical drying models are offered for both the beds and the effect of the air temperature and velocity on the drying model constants was determined by fitting the experimental data using regression analysis techniques. The three models satisfactorily described the drying characteristics of peppercorns especially for the Henderson and Pabis model. The RFBW with e/H=0.4375 is preferable in the study. © 2011 Elsevier Ltd.