Skip to main content

Advertisement

SpringerLink
Log in

Experimental investigation and mathematical modeling of drying of green tea leaves in a multi-tray cabinet dryer

  • Original
  • Published:
Heat and Mass Transfer Aims and scope Submit manuscript

Abstract

Although many experimental investigations have been carried out on the drying of foodstuffs in the tray dryers, little detailed analysis is available in the literature on the mathematical modeling of simultaneous heat and mass transfer in these types of dryers. In this work, drying behavior of green tea leaves was investigated in a multi-tray cabinet dryer. A mathematical model was developed for prediction of the moisture content and temperature of green tea leaves and also the humidity and temperature of the drying air, in the trays of the dryer. Each tray was considered as a fixed bed of tea leaves. The proposed model was solved, after dividing the bed into a series of thin layers, using a finite difference method and a trial and error technique. Equilibrium moisture contents and moisture diffusivity values, used in the mathematical model, were estimated and correlated for the green tea, used in this study. The predictions of the model showed a good agreement (MRE lower than 5%) with the experimental data, obtained from drying of green tea leaves in a domestic three-tray dryer at 60 and 70 °C. The effect of drying air velocity, temperature and the number of the green tea leaves in each tray was investigated on the drying behavior of green tea in the dryer.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

Abbreviations

A :

Area (m2)

C :

specific heat (\( \frac{j}{kg{.}^oC\kern0.5em } \))

D :

Effective diffusivity (m2/s)

hc :

Convective heat transfer coefficient (\( \frac{w}{m^2{.}^oC\kern0.5em } \))

H :

Height of the bed of the tea in a tray (m)

K :

Thermal conductivity (\( \frac{w}{m{.}^oC\kern0.5em } \))

L:

Characteristic length (m)

\( \dot{m} \) :

Mass flow rate (m3/s)

m :

Mass (m3)

N:

Number of the particles in a tray

NR :

Number of the layers inside half of a tea leaf

Nt :

Number of time increments

Nz :

Number of the layers in a tray

Nu:

Nusselt number

P :

Pressure (N/m2)

p sat :

Saturated pressure of water (N/m2)

\( {\dot{q}}_{conv} \) :

Rate of convective heat transfer (w)

\( {\dot{q}}_{evap} \) :

Rate of heat transfer in form of Latent heat of evaporation(w)

\( {\dot{q}}_{Temp} \) :

Rate of accumulation of energy(w)

R:

Half thickness of a tea leaf (m)

Re:

Reynolds Number

Rh:

Relative humidity

t :

Time (s)

T:

Temperature (°C)

\( {\overline{T}}_g \) :

the average temperature of the drying air in the layer j (°C)

U:

Apparent Velocity (m/s)

V:

Volume (m3)

X:

Moisture content in a particle based on dry basis (kgmoisture/kgDry_particle)

\( \overline{X} \) :

The average moisture content of the tea leaves (kgmoisture/kgDry_particle)

Y:

Fraction of vapor in drying gas based on dry basis (kgvapor/kgDry_gas)

Z:

Height of any point in the bed of tea particle from the bottom of that bed (m)

0:

At the beginning

amb:

The ambient condition.

bs :

Bone-dried Solid

eq :

Equilibrium

g :

Gas, drying air

in :

Into a tray dryer

i :

Finite deference index in r direction inside a typical particle

j :

Finite difference index in z-direction of the bed of tea particles on a desired tray

p :

Particle

k :

Index of the tray

n :

Finite difference index of time

Δz:

Height of an element in layer of tea leaves in a tray(m)

Δr:

Length of a layer inside a tea leaf (m)

Δt:

Time increment (s)

λ:

Latent heat of evaporation (j/kg)

μ :

Dynamics viscosity (kg.m/s)

ρ :

Density (Kg/m3)

References

  1. Ghodake HM, Goswami TK, Chakraverty A (2007) Moisture sorption isotherms, heat of sorption and vaporization of withered leaves, black and green tea. J Food Eng 78:827–835. https://doi.org/10.1016/j.jfoodeng.2005.11.023

    Article  Google Scholar 

  2. He X-Y, Liu J-F, Huang Z-H (2011) Preparation of cold brew tea by explosion puffing drying at variable temperature and pressure. Dry Technol 29:888–895. https://doi.org/10.1080/07373937.2010.547969

    Article  Google Scholar 

  3. Tang W-Q, Li D-C, Lv Y-X, Jiang J-G (2011) Concentration and drying of tea polyphenols extracted from green tea using molecular distillation and spray drying. Dry Technol 29:584–590. https://doi.org/10.1080/07373937.2010.516851

    Article  Google Scholar 

  4. Kiranoudis CT, Maroulis ZB, Marinos-Kouris D, Tsamparlis M (1997) Design of tray dryers for food dehydration. J Food Eng 32:269–291. https://doi.org/10.1016/S0260-8774(97)00010-1

    Article  Google Scholar 

  5. Benmakhlouf N, Azzouz S, El Cafsi A (2018) Experimental and mathematical investigation of parameters drying of leather by hot air. Heat Mass Transf 54:3695–3705. https://doi.org/10.1007/s00231-018-2392-5

    Article  Google Scholar 

  6. Sami S, Etesami N, Rahimi A (2011) Energy and exergy analysis of an indirect solar cabinet dryer based on mathematical modeling results. Energy 36:2847–2855. https://doi.org/10.1016/j.energy.2011.02.027

    Article  Google Scholar 

  7. Amanlou Y, Zomorodian A (2010) Applying CFD for designing a new fruit cabinet dryer. J Food Eng 101:8–15. https://doi.org/10.1016/j.jfoodeng.2010.06.001

    Article  Google Scholar 

  8. Dhanushkodi S, Wilson VH, Sudhakar K (2017) Mathematical modeling of drying behavior of cashew in a solar biomass hybrid dryer. Resour Technol 3:359–364. https://doi.org/10.1016/j.reffit.2016.12.002

    Article  Google Scholar 

  9. Pusat S, Akkoyunlu MT, Erdem HH, Dağdaş A (2015) Drying kinetics of coarse lignite particles in a fixed bed. Fuel Process Technol 130:208–213. https://doi.org/10.1016/j.fuproc.2014.10.023

    Article  Google Scholar 

  10. Bains MS, Ramaswamy HS, Lo KV (1989) Tray drying of apple puree. J Food Eng 9:195–201. https://doi.org/10.1016/0260-8774(89)90040-X

    Article  Google Scholar 

  11. Cronin K, Kearney S (1998) Monte Carlo modelling of a vegetable tray dryer. J Food Eng 35:233–250. https://doi.org/10.1016/S0260-8774(98)00011-9

    Article  Google Scholar 

  12. Vijayan S, Thottipalayam Vellingiri A, Kumar A (2017) Thin layer drying characteristics of curry leaves (Murraya koenigii) in an indirect solar dryer. Therm Sci. https://doi.org/10.2298/TSCI17S2359V

    Article  Google Scholar 

  13. Colak N, Hepbasli A (2007) Performance analysis of drying of green olive in a tray dryer. J Food Eng 80:1188–1193. https://doi.org/10.1016/j.jfoodeng.2006.09.017

    Article  Google Scholar 

  14. Rabha DK, Muthukumar P (2017) Performance studies on a forced convection solar dryer integrated with a paraffin wax–based latent heat storage system. Sol Energy 149:214–226. https://doi.org/10.1016/j.solener.2017.04.012

    Article  Google Scholar 

  15. Kumar A, Ranjan S, Prakash O, Shukla A (2017) Exergy Analysis of Solar Dryers. In: Green Energy and Technology. pp 239–262

    Chapter  Google Scholar 

  16. Yildirim N, Genc S (2017) Energy and exergy analysis of a milk powder production system. Energy Convers Manag 149:698–705. https://doi.org/10.1016/j.enconman.2017.01.064

    Article  Google Scholar 

  17. Huttunen M, Holmberg A, Stenström S (2017) Modeling fixed-bed drying of bark. Dry Technol 35:97–107. https://doi.org/10.1080/07373937.2016.1161645

    Article  Google Scholar 

  18. Zare D, Minaei S, Mohamad Zadeh M, Khoshtaghaza MH (2006) Computer simulation of rough rice drying in a batch dryer. Energy Convers Manag 47:3241–3254. https://doi.org/10.1016/j.enconman.2006.02.021

    Article  Google Scholar 

  19. Dalpasquale VA, Sperandio D, Monken e Silva LH, Kolling E (2008) Fixed-bed drying simulation of agricultural products using a new backward finite difference scheme. Appl Math Comput 200:590–595. https://doi.org/10.1016/j.amc.2007.11.029

    Article  MathSciNet  MATH  Google Scholar 

  20. Herman E, Rodriguez GC, Garcia MA (2001) Mathematical modeling for fixed-bed drying considering heat and mass transfer and interfacial phenomena (vol 19, pg 137, 2001). Dry Technol 19:2343–2362. https://doi.org/10.1081/Drt-100107503

    Article  Google Scholar 

  21. Esmailie F, Ghadamian H, Aminy M (2018) Transport phenomena study in a solar spouted bed dryer within a draft tube. Environ Prog Sustain Energy 37:488–497. https://doi.org/10.1002/ep.12670

    Article  Google Scholar 

  22. Baldino N, Gabriele D, Gentile L et al (2017) Drying of sausages made from the meat of black and white pigs: numerical modeling and structural investigation. Dry Technol 35:724–735. https://doi.org/10.1080/07373937.2016.1209681

    Article  Google Scholar 

  23. Sinija VR, Mishra HN (2008) Moisture sorption isotherms and heat of sorption of instant (soluble) green tea powder and green tea granules. J Food Eng 86:494–500. https://doi.org/10.1016/j.jfoodeng.2007.10.026

    Article  Google Scholar 

  24. Botheju WS, Amarathunge KSP, Mohamed MTZ (2008) Modeling moisture desorption isotherms and thermodynamic properties of fermented tea Dhool ( Camellia sinensis var. assamica ). Dry Technol 26:1294–1299. https://doi.org/10.1080/07373930802307324

    Article  Google Scholar 

  25. Marinos-Kouris D, Maroulis Z (2006) Transport properties in the drying of solids. In: Handbook of industrial drying, Third edn. CRC Press, pp 82–108

  26. Chungu AS, Jindal VK (1993) MODELING OF ROUGH RICE DRYING IN THIN VERTICAL COLUMNS. Dry Technol 11:1337–1351. https://doi.org/10.1080/07373939308916902

    Article  Google Scholar 

  27. Arslan N, Togˇrul H (2006) The fitting of various models to water sorption isotherms of tea stored in a chamber under controlled temperature and humidity. J Stored Prod Res 42:112–135. https://doi.org/10.1016/j.jspr.2005.01.001

    Article  Google Scholar 

  28. Anwar SI, Tiwari GN (2001) Convective heat transfer coefficient of crops in forced convection drying – an experimental study. Energy Convers Manag 42:1687–1698. https://doi.org/10.1016/S0196-8904(00)00160-6

    Article  Google Scholar 

  29. Earle RL (1983) Thermal data for some food products. In: Unit Operations in Food Processing, Second. Elsevier, Amsterdam, pp 187–188

  30. Nadi F, Tzempelikos D (2018) Vacuum drying of apples (cv. Golden delicious): drying characteristics, thermodynamic properties, and mass transfer parameters. Heat Mass Transf 54:1853–1866. https://doi.org/10.1007/s00231-018-2279-5

    Article  Google Scholar 

  31. Horuz E, Bozkurt H, Karataş H, Maskan M (2018) Simultaneous application of microwave energy and hot air to whole drying process of apple slices: drying kinetics, modeling, temperature profile and energy aspect. Heat Mass Transf 54:425–436. https://doi.org/10.1007/s00231-017-2152-y

    Article  Google Scholar 

  32. Dehghannya J, Bozorghi S, Heshmati MK (2018) Low temperature hot air drying of potato cubes subjected to osmotic dehydration and intermittent microwave: drying kinetics, energy consumption and product quality indexes. Heat Mass Transf 54:929–954. https://doi.org/10.1007/s00231-017-2202-5

    Article  Google Scholar 

  33. Crank J (1975) Diffusion in a plane sheet. In: The Mathematics of Diffusion, 2nd ed. Oxford University Press, Oxford

Download references

Author information

Authors and Affiliations

  1. Chemical Engineering Department, Faculty of Engineering, University of Guilan, Rasht, Iran

    Abbas Shomali & Behrooz Abbasi Souraki

Authors
  1. Abbas Shomali
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Behrooz Abbasi Souraki
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to Abbas Shomali or Behrooz Abbasi Souraki.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Shomali, A., Abbasi Souraki, B. Experimental investigation and mathematical modeling of drying of green tea leaves in a multi-tray cabinet dryer. Heat Mass Transfer 55, 3645–3659 (2019). https://doi.org/10.1007/s00231-019-02662-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00231-019-02662-6

Search

Navigation