scholarly journals Effect of the initial moisture content of the paddy drying operation for the small community

2020 ◽  
Vol 51 (3) ◽  
pp. 176-183
Author(s):  
Surachai Hemhirun ◽  
Pracha Bunyawanichakul
Keyword(s):  
Moisture Content ◽  
Specific Energy Consumption ◽  
Initial Moisture Content ◽  
Cross Flow ◽  
Value Added ◽  
Airflow Rate ◽  
Small Community ◽  
Rotary Valve ◽  
Grain Moisture ◽  
Speed Rotation

After the harvest, the paddy would contain high and unequal initial moisture content, depending on the season and harvest time. As a result, the dehydration was caused by using the dryer while feeding the paddy grain unequal moisture content, the dryer should be properly adjusted to retain the final moisture content as per the rice mill and storage requirements and low specific energy consumption (SEC) were used for the drying operation per one cycle product. The objective of this paper was to study the paddy drying operation by using a continuous cross-flow dryer at a different initial grain moisture content. The research was divided into two steps, the first step began with the drying operation with levels of the initial moisture content 20.0%wb that involved the adjustment of the parameters of an average hot-air temperature 150°C, the speed rotation of an eccentric set of 11.52 rad s–1, the airflow rate 0.016 m3 s–1, and speed rotation of rotary valve 0.21 rad s–1 (approximately feed rate 36 kg h–1), by the application of these parameters, from the obtained results, it was found that grain moisture content of paddy was reduced from 20.0%wb to 14.3%wb as desired, and SEC of 3.60 MJ kg–1 water was evaporated. Then the second step, these parameters were tested in terms of the drying operation that the initial grain moisture content decreased and increased 18.1%wb and 23.0%wb, respectively. The results showed that when the initial grain moisture content decreased, the paddy drying operation reduced the moisture of the paddy until the final grain moisture content became 12.9%wb which was lower than the desired expectation, On the contrary, when the initial moisture content increased, the final grain moisture content became 16.1%wb. This was not sufficient for storage or planting in the next crop year which required re-drying operation as well. Furthermore, the results can be used as reference data and a guideline for small communities in Thailand to appropriate decisions with the drying cost and the value-added tax.

Mathematical Modeling of the Process of Operation of the Drying Chamber of a Tower Grain Dryer With a Suction Air Flow

2020 ◽  
pp. 114-121
Author(s):  
Viktor Shvidia ◽  
◽  
Serhii Stepanenko ◽  
Keyword(s):  
Moisture Content ◽  
Air Flow ◽  
Initial Moisture Content ◽  
Material Balance ◽  
Operating Parameters ◽  
Conservation Of Energy ◽  
Grain Moisture ◽  
Optimal Mode ◽  
Drying Chamber ◽  
Main Operating

In the article, a drying scheme in a tower grain dryer has been developed, equations for the conservation of energy and material balance for grain, equations for mass transfer and heat transfer between the drying agent and grain have been drawn up. On their basis, analytical dependences of changes in the temperature and moisture content of grain, moisture content and temperature of the drying agent along and in the width of the drying channel were obtained, depending on the operating parameters (the value of rarefaction in the drying channel, the speed of grain movement along the drying channel, the speed of movement of the drying agent, the initial temperatures of the grain and drying agent, initial moisture content of grain, as well as initial moisture content of drying agent). Their analysis facilitates the work in choosing the optimal mode. The developed analytical dependences of changes in the main drying parameters (moisture and temperature of grain, moisture content and temperature of the drying agent) along the length and width of the drying channel in tower dryers with suction air flow make it possible to link the main operating parameters, which facilitate the choice of rational drying modes.

scholarly journals STUDY OF GRAIN DRYING IN THE AUTOMATED GRAIN DRYING UNIT

2018 ◽  
Vol 12 (4) ◽  
pp. 29-34
Author(s):  
S. A. Pavlov ◽  
T. F. Frolova
Keyword(s):  
Moisture Content ◽  
Coming Out ◽  
Transfer Functions ◽  
Heating Temperature ◽  
Initial Moisture Content ◽  
Experimental Studies ◽  
Research Purpose ◽  
Complex Object ◽  
Grain Moisture ◽  
Grain Drying

Mine and column grain dryers are a fairly complex object of control in the production line. The process of grain drying is characterized  by a large number of parameters, quantitatively and qualitatively characterizing the dryer operation. First of all, this includes the criteria of maximum performance and minimum deviations of the moisture content of the dried grain from the standard values. These criteria, as studies show, are interconnected with each other: an increase in the performance П of the dryer leads to an increase in the moisture content of the grain coming out of it, and, conversely, an attempt to reduce the moisture content of grain causes the need to reduce the performance П. (Research purpose) The research purpose is to develop the expression for the transfer functions of the of grain flow control depending on perturbations of the initial moisture content and the maximum grain temperature, as well as to conduct experimental studies. (Materials and methods) The authors have developed simplified mathematical models of moisture perturbation compensation of grain coming in for drying and its heating temperature in a drying chamber by changing the dryer performance on the basis of theoretical-and-experimental studies. (Results and discussion). The authors  have obtained  expressions to control the process performance when the current humidity and temperature change through the dryer performance parameters as a function of grain moisture flow and heat used to grain heating up to an acceptable temperature. Farm tests of developed transition management functions have been implemented for dryer SZT-16 controlled by PLC S7-1200 Siemens and operating in an automatic mode. Tests have been conducted on the “Babachev” farm, Karachev district of the Bryansk region in the process of drying food wheat grain. (Conclusion) It has been confirmed that the dryer performance is determined not only by the rated capacity but also by the deviation of the current moisture content of grain from the specified values and by the ratio of the amount of heat used for evaporating and heating. The dryer performance at constant initial humidity is determined by its rated performance, the maximum specified difference of grain temperatures, as well as the ratio of the amounts of heat used for evaporating and heating.

scholarly journals Forma e tamanho de grãos de soja para diversos teores de água

2018 ◽  
Vol 39 (6) ◽  
pp. 2821
Author(s):  
Wilker Alves Morais ◽  
Osvaldo Resende ◽  
Fernando Nobre Cunha ◽  
Vitor Marques Vidal ◽  
Nelmício Furtado da Silva ◽  
...  
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Surface Area ◽  
Initial Moisture Content ◽  
Correlation Coefficients ◽  
Volumetric Shrinkage ◽  
Linear Regression Models ◽  
Moisture Contents ◽  
Soybean Cultivars ◽  
Grain Moisture

Physical properties of soybean grains present differences as a function of cultivars and moisture content, with the correlation between physical properties. This study aimed to determine the characteristics related to the physical properties of grains with different moisture contents of three soybean cultivars. The experimental design was completely randomized design in a 3 × 6 factorial scheme with three replications, consisting of three soybean cultivars (6266 RSF IPRO, BMX Potência RR, and 14403Z6001) and six grain moisture contents (11, 13, 15, 17, 19, and 21% wb). Soybean grains presented an initial moisture content of 11.0, 11.0, and 10.8% wb, respectively for 6266 RSF IPRO, BMX Potência RR, and 14403Z6001. The other moisture contents were obtained by soaking in a BOD chamber maintained at 25 °C and 93% of relative humidity. We assessed volume, roundness, sphericity, surface area, volumetric shrinkage, and volumetric shrinkage rate. The data were submitted to the analysis of variance by the F-test (p < 0.05) and when significant, regression analysis was performed for grain moisture contents and the means of cultivars were compared by the Tukey’s test. Pearson’s correlation analysis was also carried out to represent the linearity between grain physical properties. The cultivar BMX Potência RR obtained the highest results for volume, roundness, sphericity, and surface area. Volume and surface area increased as the moisture content of soybean grains increased; the opposite was observed for roundness and sphericity. A linear increase in volumetric shrinkage was observed as moisture content increased. The values of the correlation coefficients of the linear regression models can be used to describe the relationships between physical properties.

Process optimization of paddy drying in cross-flow aerated drying cum storage bin

2020 ◽  
Vol 44 (03) ◽  
pp. 7-15
Author(s):  
Sruthi N. U. ◽  
U. C. Lohani ◽  
N. C. Shahi ◽  
J. P. Pandey
Keyword(s):  
Air Temperature ◽  
Specific Energy Consumption ◽  
Cross Flow ◽  
Moisture Diffusivity ◽  
Airflow Rate ◽  
Experimental Conditions ◽  
Heating Chamber ◽  
Drying Time ◽  
Drying Rates ◽  
Drying Conditions

A cross-flow aerated drying cum storage bin was developed and the drying conditions for paddy was optimised. The drying cum storage bin consisted of a cylindrical outer drum with two inner basins having perorated walls made of galvanised iron to hold paddy, and a central perforated vertical duct. A blower (1.5 kW) connected at the base supplies air to the heating chamber (with 1 kW heater coil) and moves vertically through the central duct. The hot air passes horizontally through the grain bulk taking the moisture and moves towards the perforated walls of the bin and exit through the space between the drum and the basins. Drying experiments were conducted with bed thickness of 15 cm to study the drying characteristics of paddy and evaluate the performance of the dryer. Paddy was dried from 18 to 12% (wb) moisture content with the independent parameters selected being drying air temperature (35, 40 and 45 °C) and airflow rate (15, 21 and 27 m3 /h). The drying time varied 1.5 to 4.75 hours over the entire experimental conditions. The analysis of drying rates for both top and bottom bins showed minimum variation indicating uniform drying throughout the depth of the bin. The estimated optimum conditions of drying were 45°C temperature and 27 m3 /h airflow rate. The predicted values of responses at optimised conditions were 1.51 hours of drying time, 6.05x10-7 m2 /s of effective moisture diffusivity, 0.078 W/m2 K of heat transfer coefficient, and 8.23x105 kJ/kg of specific energy consumption. Further, exergy analysis indicated that exergy loss increased with increase in drying air temperature and airflow rate.

scholarly journals Analysis on Photovoltaic Energy-Assisted Drying of Green Peas

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Onur Taşkın ◽  
Nazmi İzli ◽  
Ali Vardar
Keyword(s):  
Energy Consumption ◽  
Moisture Content ◽  
Air Temperature ◽  
Specific Energy Consumption ◽  
Initial Moisture Content ◽  
Air Velocity ◽  
Rehydration Ratio ◽  
Total Energy Consumption ◽  
Photovoltaic Energy ◽  
Green Peas

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.

scholarly journals Electrically enhanced drying of white champignons

2018 ◽  
Author(s):  
Alex Martynenko ◽  
Ivanna Bashkir ◽  
Tadeusz Kudra
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Cross Flow ◽  
Water Evaporation ◽  
Drying Rate ◽  
Residual Water ◽  
Ionic Wind ◽  
Air Stream ◽  
Wide Range ◽  
Forced Air

Effects of convective cross-flow of air in electrohydrodynamic (EHD) drying on drying rate of 5 mm slices of champignons have been investigated. Electro-convection issued from discharge electrode (42 needles arranged into 6×7 rows with 2×2 cm spacing, 18 kV DC voltage and 3.5 cm gap) provided average ionic wind velocity of 1.0 m/s flowing perpendicularly to the surface of champignons slices, while forced air stream at atmospheric pressure 1000 kPa, superficial velocity 1.0 m/s, temperature 22-24°C, and relative humidity 25-40%, was blown parallel to the surface of champignons slices. To study interactions between forced air cross-flow and electro-convection, the experimental protocol was designed, exploring three cases in various combinations: (1) Sole EHD, (2) air cross-flow, and (3) EHD with simultaneous air cross-flow. The case # 3 was found to be the most efficient, resulting in 10.2 g/h of water evaporation whereas drying rate was 6.6 g/h (# 1) and 3.6 g/h for (# 2). Such numbers imply that these effects are additive. In some combinations the effect of air cross-flow was the same (3.6 g/g), but electro-convection was significantly suppressed to 3.2 g/h likely because air stream removed surface water, which reduced charge transfer and electro-diffusion.In trials with different initial moisture content it was found that drying kinetics followed exponential decay in the wide range of initial moisture contents from 4.9 to 12.0 g/g (db). Drying rate due to forced air convection was found to be independent of moisture content, whereas drying rate due to electro-convection significantly depended on the moisture content. For example, the EHD drying rate of fresh-cut champignons slices with initial moisture content 10.74 g/g was 0.237 g/h, while the slices after two days in the cooler (initial moisture content dropped to 4.92 g/g) it was 0.418 g/h. Also, it was found that electro-convective drying could not remove all residual water. At the end of drying the equilibrium moisture content attained 0.2 - 0.3 g/g (aw~0.3).It appears that performance of EHD drying depends also on the product porosity as water can exist as free in open pores or be trapped in closed pores. In some experiments we observed rotation of champignon slices in the plane perpendicular to ionic wind. It happened at the end of drying when slices were light enough to be lifted by electrostatic force and dragged by the vortex. This phenomenon could be attributed either to the effect of DC electric field on polarized water molecules trapped in closed pores, or it could be electrostatic effect of ionic wind on charged porous body. Also, the hypothesis that EHD has both linear and rotational (vortex) components require further investigation.

scholarly journals Purwarupa dan Kinerja Pengering Gabah Hybrid Solar Heating dan Photovoltaic Heater dengan Sistem Monitoring Suhu

2020 ◽  
Vol 12 (1) ◽  
pp. 24-32
Author(s):  
Usman Usman ◽  
Akhyar Muchtar ◽  
Umar Muhammad ◽  
Nunik Lestari
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Electrical Energy ◽  
Temperature Monitoring ◽  
Solar Panels ◽  
Drying Process ◽  
Grain Moisture ◽  
Measurement Tools ◽  
Drying Efficiency ◽  
And Control

Grain drying is a process to reduce grain moisture content to certain conditions, so the grain can last longer in storage. The grain dryer model used in this research was Indirect Type Solar Dryer (ITSD). In order to make this dryer can work at night, heating element that used electrical energy from solar panels was added. This energy is a renewable and environmentally friendly energy. This dryer was equipped with a temperature monitoring system and control of the photovoltaic heater. The results of temperature monitoring and voltage sensors to controlling photovoltaic heaters based on validation are categorized as work measurement tools, because they have an error of 0.5% – 2%. Whereas the relay works when the battery voltage is 11 - 10.9 V. This dryer can dry grain to reach a moisture content of 14.90% from initial  moisture content of 48.46%. The drying process lasts for 11 hours, which is 7 hours using solar energy and 4 hours using photovoltaic heaters. The average temperature produced by dryer system during the drying process is 35.28 °C with a drying efficiency of 60.14%.

scholarly journals Pengaruh kecepatan udara dan massa gabah terhadap kecepatan pengeringan gabah menggunakan pengering terfluidisasi

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
S. Syahrul ◽  
M. Mirmanto ◽  
S. Romdani ◽  
S. Sukmawaty
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
National Standards ◽  
Drying Process ◽  
Air Velocity ◽  
Drying Time ◽  
Grain Processing ◽  
Grain Moisture ◽  
Time Required ◽  
Drying Chamber

Grain processing does not meet the actual grain harvests. This is due to the unsuitable drying process. Milling grain entrepreneurs and farmers in Indonesia are currently conducting a drying process under the sun. Based on the National Standards Body (BSN), grain moisture content must be at 14% to maintain the grain at high qualities. The purpose of this study is to determine the effect of velocity and grain mass variations on drying times. The grain used in this study contains an initial moisture content of 22% ± 0.5%. The grain is dried by inserting it into the drying chamber and varying the air velocities and grain mass. The air velocities used are 4 m/s, 5 m/s, 6 m/s and the variations of the grain mass are 1 kg 2 kg and 3 kg. The results show that increasing the air velocity decreases the drying time. On the other hand, when the grain mass is increased, the drying time elevates. The air velocity and mass of the grain that results in the fastest drying time are 6 m/s and 2 kg. The time required for achieving the water content of 13.6% is 30 menit. At the air velocity of 4 m/s, and the grain masses of 1 kg, 2 kg, and 3 kg, to achieve moisture contents of 13.4%, 13.5% and 13.4% the drying time needs 50 minutes.

Isotherm Adsorption Behavior and Drying Kinetics of Black Pepper

2012 ◽  
Vol 622-623 ◽  
pp. 1580-1585
Author(s):  
A. Sae-Khow ◽  
S. Tirawanichakul ◽  
Y. Tirawanichakul
Keyword(s):  
Energy Consumption ◽  
Relative Humidity ◽  
Moisture Content ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Initial Moisture Content ◽  
Black Pepper ◽  
Drying Kinetics ◽  
Drying Temperature ◽  
Kinetics Of

The objective of this research were to evaulate equilibrium moisture contents (EMC) of black pepper using the gravimetric-static method and to study the drying kinetics of pepper using 1-stage hot air (HA) drying, 1-stage infrared (IR) drying, 2-stages drying with microwave (MW) and IR and 2-stages drying with MW and HA including to the specific energy consumption determination. For the first objective, the five saturated salt solutions were used for providing equlibrate state between pepper and surrounding at temperature ranging of 40-65°C correlated to relative humidity ranging of 10-90%. The results showed that EMC value decreased with increasing temperature at constant relative humidity. To evaluate the EMC value, the experimental data was simulated by four conventional EMC models and the criteria of the best fiiting models were determined by the determination of coefficient (R2) and the root mean square error (RMSE) value. The results showed that the calculated value using the Modified Oswin model was the most suitable for describing the relationship among equilibrium moisture content, relative humidity and temperature. To study effect of drying condition on drying kinetics, the initial moisture content and final moisture content after drying of papper sample was in ranges of 300-400% dry-basis and 12-16% dry-basis, respectively. The experimetal data were simulsted using empirical drying models and the results showed that the drying temperature relatively affected to drying rate of pepper while the evolution of moisture transfer was in the drying falling ratefor all drying strategies. The 1-stage IR drying and 2-stages drying with MW and IR provided low specific energy consumption (SEC) (0.11-0.15 MJ/kg of water evaporated) compared to the other drying strategies (0.87-1.52 MJ/kg of water evaporated). Moreover, the SEC of pepper drying decreased with increasing of drying temperature.

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