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

2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Reza Amiri Chayjan ◽  
Mohammad Kaveh ◽  
Nesa Dibagar ◽  
Moein Zarrin Nejad

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.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hany S. EL-Mesery ◽  
Mona A. Elabd

Abstract Okra pods were dried using the following drying regimes; microwave (MWD), infrared (IRD) and convective hot-air drying (CHD). The objective of this investigate was to report the influences of drying methods on okra quality under different drying conditions. Data analysis showed that rehydration ratio and colour change increased with increase in drying air temperature and air velocity while specific energy consumption and shrinkage ratio decreased with increase in drying air temperature under (CHD). The rehydration ratio and colour of dried okra increased with increase in both infrared intensity but it also increased with a decrease in air velocity under (IRD). In the MWD method, drying time, specific energy consumption and shrinkage ratio decreased with increases in microwave power while the rehydration ratio and colour increased. Optimum drying period, specific energy consumption, colour, shrinkage and rehydration ratio were obtained for microwave drying. The model of Midilli et al. is the greatest for describing the drying curves of okra under all the drying processing conditions.


Author(s):  
Thatchapol Chungcharoen ◽  
Warunee Limmun ◽  
Sansanee Sansiribhan

The fluidized bed technique was applied to use with the Robusta coffee in this research. fluidization behavior and specific energy consumption were investigated under various coffee forms and distributor hole angles. Moreover, the minimum fluidization velocity (Vmf) was also determined. Experiments are carried out in a sample bed height of 5 cm with ambience air. In this study, two coffee forms (Ripe coffee cherries; RCC and parchment coffee; PC) and three distributor hole angles (45º, 60º and 90º) are examined. The experimental result shown that the fluidization behavior is influenced by coffee form and distributor hole angle. The RCC and distributor hole angle of 60º provided the low pressure drop throughout the superficial air velocity. The low values of Vmf and SEC were also achieved in the RCC and distributor hole angle of 60º.


2021 ◽  
Vol 39 (3) ◽  
pp. 810-816
Author(s):  
Wan Nurlaila Mat Desa ◽  
Ahmad Fudholi ◽  
Henny Sudibyo ◽  
Ghalya Pikra ◽  
Nugrahaning Sani Dewi ◽  
...  

In this study, a greenhouse solar dryer with double-pass multi-hollow collector for leaf drying was design, constructed, and evaluated. From the result, the double pass solar air collector with multi-hollow tube is capable of increasing air temperature by 5.5℃-10.8℃ compared to ambient air temperature. Thermal efficiency of the dryer was evaluated for passive and active modes, where 47.2% and 50% are recorded respectively. The moisture reduction on mass basis in passive and active dryer recorded was 44% and 74%, respectively. The specific moisture extraction rate (SMER) and specific energy consumption (SEC) of passive dryer was determined to be 0.198 kg per kWh and 5.047 kWh per kg, and active dryer at 0.210 kg per kWh and 4.769 kWh per kg, respectively.


Author(s):  
M Yahya ◽  
Hendriwan Fahmi ◽  
Syafrul Hadi ◽  
Edison Edison

The performance of a fluidized bed dryer integrated biomass furnace with air preheater (FBD with APH) and a fluidized bed dryer integrated biomass furnace without air preheater (FBD without APH) for drying of paddy  have been evaluated. The  FBD with APH and FBD without APH decreased the moisture of paddy from 24% (wet basis) to 14% (wet basis) within 43 and 47 minutes with average temperatures and relative humidities of 59.58 <sup>o</sup>C and 59.14<sup>o</sup>C, and 18.81% and 18.68%, respectively. The drying rate of paddy varied in the range of 0.11 kg/min-0.32 kg/min and 0.10 kg/min- 0.30 kg/min for FBD with APH and FBD without APH, with average values of 0.18kg/min and 0.17kg/min, respectively. The minimum, maximum, and average value specific moisture evaporation rate (SMER) was  0.20 kg/kWh, 0.57 kg/kWh, and 0.31 kg/kWh, respectively for FBD with APH, as well as 0.149 kg/kWh, 0.448 kg/kWh, and 0.252  kg/kWh, respectively, for FBD without APH.  The specific energy consumption (SEC), the specific electrical energy consumption (SEEC), and the specific thermal energy consumption (STEC) were varied from 1.749 kWh/kg to 5.076 kWh/kg, 0.090 kWh/kg to 2.872 kWh/kg, and 0.760 kWh/kg to 2.204 kWh/kg, with average values of 3.528 kWh/kg, 1.96 kWh/kg, and 1.532 kWh/kg, respectively for FBD with APH, as well as from 2.234 kWh/kg to 6.702 kWh/kg, 1.056 kWh/kg to 3.167 kWh/kg, and 1.179 kWh/kg to 3.536 kWh/kg, with average values of 4.391 kWh/kg, 2.075 kWh/kg, and 2.316 kWh/kg, respectively, for FBD without APH. The thermal efficiencies of the FBD with APH and  FBD without APH were varied between 12.4% and 37.93%, and 9.78% and 29.82%, resvectively, with average values of 20.78% and 16.61%. The thermal efficiency of FBD with APH was higher compared to FBD without APH.


2007 ◽  
Vol 25 (4) ◽  
pp. 261-271
Author(s):  
Huseyin Gunerhan

In this study, an investigation on olive cake as on alternative fuel and effect of drying air temperature and drying air velocity is conducted. In many developing countries olive cake is considered as a biomass and can be used in very large amounts at very low cost. The effect of drying air temperature and air velocity at constant humidity conditions was studied. A process for drying of olive cake in a fluidized bed dryer is proposed. Results of these experiments of the olive cake indicated that olive cake has an excellent potential to be a renewable source of energy and suitable material for these types of dryers.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Onur Taşkın ◽  
Nazmi İzli ◽  
Ali Vardar

A photovoltaic energy-assisted industrial dryer has been analyzed. The dryer has been tested in various weather and working conditions with 3 kg of green peas from 75.6% initial moisture content to 20% final moisture content (w.b.). The effect of various drying air temperatures at three levels (40, 50, and 60°C) and two distinct air velocities (3 m/s and 4 m/s) was examined. Drying performance was assessed with regard to criteria including drying kinetics, specific and total energy consumption, and color and rehydration ratio. The results have proved that total drying duration reduces as air velocity rate and drying air temperature raise. Relying upon the drying durations, the generation performances of photovoltaic panels were between 5.261 and 3.953 W. On the other part, energy consumptions of dryer were between 37.417 and 28.111 W. The best specific energy consumption was detected in 50°C at 3 m/s for 600 minutes with 7.616 kWh/kg. All drying conditions caused darkening as color parameters. Rehydration assays have showed that rehydrated green peas attained higher capacity with raised air temperature and air velocity.


2020 ◽  
Vol 2 (2) ◽  
pp. 53
Author(s):  
Abadi Jading ◽  
Paulus Payung ◽  
Eduard Fransisco Tethool

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).


2021 ◽  
Vol 21 (2) ◽  
pp. 74-80
Author(s):  
Juli Mrihardjono ◽  
Didik Ariwibowo ◽  
Sutrisno Sutrisno ◽  
Dista Yoel Tadeus

Atmosphere Water Harvester (AWH) was investigated to get water collected from air in elevated performance. Improvement was performed by introducing a series-arrangement of two evaporators. Air flew through the evaporators in cross-flow. This arrangement would influence performance of the AWH system in title of COP, MHI, and specific energy consumption. The AWH was designed using vapor compression refrigeration system. Parameter measured to the system were refrigerant temperature in suction and discharge line, inlet and outlet pipe wall temperatures at evaporator and condenser, air velocity enter into evaporator, and electrical energy consumption. Instrument used in this research were refrigerant pressure-temperature gauge, K-type digital thermometer, digital fan anemometer, thermo-hygro meter, and kWh meter. Air temperature and RH data were 36,5 oC, 40%, and 19 oC, 42 %  for inlet and outlet air stram at evaporator, subsequently. With air velocity 1.5 m/s, the COP of the system was 3.7. Water collected  from AWH was 1.1 litres/hour with energy consumption of 1.24 kWh. The AWH could be considered as a water harvester with value of specific energy of 1.13 kWh/litre and MHI of 0,2.


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