Energy Use and Efficiency of Rice-Drying Systems II. Commercial, Cross-Flow Dryer Measurements

This study investigates the drying mechanisms of corn when it is exposed to air at elevated temperature and velocity within a cross-flow packed bed dryer. A highly-instrumented laboratory-scale experimental test dryer was constructed to batch-dry samples of 0.03 m3 (1 ft3) of high moisture corn. This is achieved using a perforated wall drying chamber with forced air at temperatures ranging from 180–240°F. The high temperature, high velocity air entering the column is supplied by a variable speed fan and a variable Wattage electric heating coil through a 0.09 m2 (1 ft2) square air duct. This device is able to precisely control the drying air temperate and flow rate, while also measuring the temperature and humidity of the air exiting the dryer. In creating and instrumenting this apparatus, tests were performed to analyze both energy use and drying rate to determine the operating conditions that find a balance between energy and time requirements for moisture removal. This study used a variety of supply air temperatures and air flow rates in drying samples of corn at two initial moisture contents (19%MC and 24%MC) to 15%MC. This is done to determine if there are notable differences in energy requirements (Btu/pound water removed) between different operating conditions. This study determined that corn undergoes a significant pre-heating process before peak drying efficiency is achieved. Current grain dryer designs should focus the most energy just after that pre-heating process for highest overall efficiencies. Additionally, this study found an inverse relationship between dry time and energy efficiency, which showed that an optimum balance between those two factors should be identified.

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On-Farm Rice Drying Energy Use

Applied Engineering in Agriculture ◽

10.13031/2013.26650 ◽

1987 ◽

Vol 3 (1) ◽

pp. 79-86

Author(s):

Lalit R. Verma ◽

Lyle Jacobsen

Keyword(s):

Energy Use ◽

Rice Drying ◽

On Farm

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Two-dimensional simulation model for dynamic cross-flow rice drying

Chemical Engineering and Processing - Process Intensification ◽

10.1016/s0255-2701(01)00117-9 ◽

2001 ◽

Vol 40 (4) ◽

pp. 355-362 ◽

Cited By ~ 10

Author(s):

T.R. Rumsey ◽

C.O. Rovedo

Keyword(s):

Simulation Model ◽

Cross Flow ◽

Two Dimensional ◽

Dimensional Simulation ◽

Rice Drying

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ANALISIS ENERGI PENGERINGAN PADI MENGGUNAKAN VERTICAL DRYER TYPE VRD60 DI DESA BIGO SELATAN KABUPATEN BOLAANG MONGONDOW UTARA

Jurnal Teknologi Pertanian (Agricultural Technology Journal ◽

10.35791/jteta.11.1.2020.29988 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Giovanni Lengkey

Keyword(s):

Total Energy ◽

Diesel Fuel ◽

Energy Use ◽

Survey Methods ◽

Rice Variety ◽

Calorific Value ◽

Drying Process ◽

Grain Moisture ◽

Materials Used ◽

Rice Drying

The purpose of this study is calculating the total energy needed during the rice drying process by using a vertical dryer VRD60 type in Bigo Selatan Village, Kaidipang Subdistrict, North Bolaang Mongondow District, and determining the efficiency of energy use during the rice drying process. The tools used were: AGRINDO dryer VRD60 type, Danoplus infrared thermometer THE-223, Sima brand weighing scale with the capacity of 500 kg, and CROWN digital grain moisture meter. Materials used were: 5,202 kg (5.2 tons) of Sultan rice variety, diesel fuel, and rice husks. The study was conducted with experimental and survey methods. Data was analyzed descriptively. The results showed that the total energy used by the dryer is 1,531,560 kcal consist of 6,300 kcal labor (humans) energy, 683,760 kcal of diesel fuel and 841,500 kcal of energy from husk usage. The biggest energy is obtained from the husk used as much as 255 kg with a calorific value of 841,500 kcal and the biggest use is to evaporate water from materials that is 450,293.1 kcal. The energy efficiency of drying from a vertical dryer VRD60 type is found to be 38.29%.

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Mathematical Modeling of a Cross-Flow Rice Dryer

Transactions of the ASABE ◽

10.13031/trans.12155 ◽

2017 ◽

Vol 60 (3) ◽

pp. 999-1009 ◽

Cited By ~ 1

Author(s):

Bhagwati Prakash ◽

Sangeeta Mukhopadhyay ◽

Terry J. Siebenmorgen

Keyword(s):

Mathematical Model ◽

Glass Transition ◽

Transition States ◽

Cross Flow ◽

Milling Quality ◽

Percentage Points ◽

Model Predictions ◽

Rice Drying ◽

The Impact ◽

The U.S

Abstract. Cross-flow dryers are the most popular industrial-scale rice dryers used in the U.S., yet few mathematical models have been developed and rigorously validated for such dryers. In addition, the glass transition states of rice kernels have never been predicted using a deep-bed drying model. In this study, a mathematical model was developed that describes the distribution of grain and air properties throughout a cross-flow dryer column. The model was validated by performing experiments in a lab dryer that was fabricated to simulate cross-flow drying. The model predictions of grain and air properties were observed to be very close to the measured values in the drying experiments; the root mean square error between the predicted and measured values of rice MC, air temperature, and air RH were less than one percentage point, 5°C, and ten percentage points, respectively. The model was then used to predict the glass transition state of starch present in rice kernels throughout the dryer column. The impact of initial MC on the glass transition states of rice kernels during cross-flow drying was also illustrated. Such predictions of rice kernel material states allow the model to be used for rice fissuring research. Additionally, the model could be applied to optimize drying operation parameters as well as improve dryer design, so as to achieve greater drying capacity, milling quality, and energy efficiency in a commercial drying operation. Keywords: Cross-flow drying, Glass transition, Mathematical model, Rice drying.

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