Modeling of moisture diffusivity, activation energy and specific energy consumption of high moisture corn in a fixed and fluidized bed convective dryer

Pengering Agitated Fluidized Bed (AFB) telah dirancang untuk pengeringan pati sagu. Untuk mengetahui kinerja pengering AFB tersebut, maka dilakukan analisis nilai indeks kinerja Heat Utilization Factor (HUF), Coefficient Of Performance (COP), Effective Heat Efficiency (EHE), dan Specific Energy Consumption (SEC) berdasarkan perlakuan suhu (50oC, 60oC, dan 70oC) dan massa input bahan (3 kg, 6 kg, dan 12 kg). Nilai indeks kinerja HUF, COP, EHE dan SEC ditentukan dengan analisis matematis. Hasil penelitian ini menunjukkan bahwa indeks kinerja pengering AFB terbaik dari semua perlakuan suhu dan massa input bahan adalah pada suhu 60oC dengan massa input bahan 12 kg, dimana nilai HUF lebih besar dari nilai COP. Nilai HUF, COP, dan EHE masing-masing adalah 53,1%, 46,9%, 70,3% dan nilai SEC 559,9 kJ/s. Nilai rata-rata HUF, COP, EHE, dan SEC dari semua perlakuan pada pengering AFB adalah 37,23%, 62,7%, 58,5%, dan 337,6 kJ/s. Kinerja pengering AFB cukup rendah, dimana nilai HUF rata-rata lebih kecil dari nilai COP rata-rata, dan energi yang digunakan cukup tinggi. Namun demikian, pengering AFB mampu mengeringkan pati sagu dengan kadar air akhir 14,4% basis basah mendekati standar mutu pati sagu kering 13%, pada suhu 70oC dengan massa bahan sebanyak 3 kg selama 5 menit (300 detik).

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Optimization of Pistachio Nut Drying in a Fluidized Bed Dryer with Microwave Pretreatment Applying Response Surface Methodology

Chemical Product and Process Modeling ◽

10.1515/cppm-2016-0048 ◽

2017 ◽

Vol 12 (3) ◽

Cited By ~ 2

Author(s):

Reza Amiri Chayjan ◽

Mohammad Kaveh ◽

Nesa Dibagar ◽

Moein Zarrin Nejad

Keyword(s):

Response Surface Methodology ◽

Energy Consumption ◽

Fluidized Bed ◽

Air Temperature ◽

Specific Energy ◽

Color Change ◽

Specific Energy Consumption ◽

Air Velocity ◽

Fluidized Bed Dryer ◽

Total Color Change

Abstract Thin-layer drying kinetics of pistachio nuts were examined experimentally as a function of drying conditions in a fluidized bed dryer with microwave pretreatment. Four drying specifications of diffusivity, shrinkage, specific energy consumption and total color change were calculated and the effects of parameters were studied. Numerous experimentations were conducted at three levels of air temperature (40, 55, 70 °C), air velocity (1.2, 2.93, 4.01 m/s), and microwave power (270, 450, 630 W). The variation ranges of diffusivity, shrinkage, energy consumption and color change were recorded from 5.01×10–10 to 5.07×10–9 m2/s, from 26.95 % to 13.13 %, from 1.04 to 9.23 kWh and from 10.44 to 17.17, respectively. According to response surface methodology, optimum condition of drying process occurred at microwave power of 630, air temperature of 70 ˚C, and air velocity of 1.2 m/s. In this optimum point, the values of diffusivity, shrinkage, specific energy consumption and total color change were 4.865×10–9, 14.22 %, 2.164 kWh and 12.312, respectively.

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Characteristics of sunflower seed drying and microwave energy consumption

International Agrophysics ◽

10.2478/v10247-012-0077-8 ◽

2013 ◽

Vol 27 (2) ◽

pp. 127-132 ◽

Cited By ~ 5

Author(s):

H. Darvishi ◽

M. Hadi Khoshtaghaza ◽

G. Najafi ◽

M. Zarein

Keyword(s):

Energy Efficiency ◽

Energy Consumption ◽

Specific Energy ◽

Microwave Power ◽

Specific Energy Consumption ◽

Moisture Diffusivity ◽

Effective Moisture Diffusivity ◽

Convective Drying ◽

Drying Time ◽

Effective Moisture

Abstract The effect of the microwave-convective drying technique on the moisture ratio, drying rate, drying time, effective moisture diffusivity, microwave specific energy consumption, and energy efficiency of sunflower seedswere investigated.Drying took place in the falling rate period. Increasing the microwave power caused a significant decrease in the drying time. The drying data were fitted to four thin-layer drying models. The performance of these models was compared using the coefficient of determination, reduced chi-square and root mean square error between the observed and predicted moisture ratios. The results showed that the Page model was found to satisfactorily describe themicrowave-convective drying curves of sunflower seeds. The effective moisture diffusivity values were estimated from Fick diffusion model and varied from 1.73 10-7 to 4.76 10-7m2s-1. Increasing the microwave power resulted in a considerable increase in drying efficiency and a significant decrease in microwave specific energy consumption. The highest energy efficiency and the lowestmicrowave specific energy consumption were obtained at the microwave power of 300 W.

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