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.

Effect of Drying on Physical Qualities and Sensory Evaluation of Herbal Germinated Brown Rice by Hot Air: Turmeric and Roselle

2013 ◽  
Vol 372 ◽  
pp. 420-423
Author(s):  
Khwanruedi Sangchum ◽  
Yutthana Tirawanichakul ◽  
Supawan Tirawanichakul
Keyword(s):  
Moisture Content ◽  
Sensory Evaluation ◽  
Initial Moisture Content ◽  
Brown Rice ◽  
Ambient Air ◽  
Drying Rate ◽  
Germinated Brown Rice ◽  
Rice Drying ◽  
Drying Conditions ◽  
Cie Lab

The object of this project was to study the effect of drying temperature on physical quality and sensory evaluation of germinated brown rice soaking with tumeric and roselle. The drying was run under the conditions of drying temperatures of 80-100°C and air velocity of 7.3 m/s. Initial moisture content of brown rice samples was of 54-55% dry-basis and was dried until the final moisture content reached to 20-25% dry-basis. After drying, the rice was tempered and then was ventilated by ambient air until its moisture content reached to 14-15% dry-basis. The experiment showed that highest drying rate is incident at 100°C. For physical qualities analysis, the results showed that the drying air temperature does not affect to head rice yield, fissured kernels, chalky grain and color (L*, a*, b* CIE-lab unit) of herbal germinated brown rice. In addition, herbal germinated brown rice drying can maintain low percentage of chalky grain compared to commercial brown rice. The soaking solution was not affect to drying rate. Finally, the sensory evaluation showed that the herbal germinated brown rice dried with all drying conditions was acceptable taste (>5).

Humidity Effects on Fluidic Temperature Devices

1974 ◽  
Vol 7 (12) ◽  
pp. 463-468
Author(s):  
John O. Geremia ◽  
Chih Wu
Keyword(s):  
Moisture Content ◽  
Ideal Gas ◽  
Humidity Effects ◽  
Dry Air ◽  
Moisture Contents ◽  
Air Stream ◽  
Wide Range ◽  
Vapour Mixture ◽  
Thermodynamic Equations ◽  
The Ideal

A fluidic temperature device, designed by and obtained from The Harry Diamond Laboratories, was tested for stability when subjected to a variation of moisture content in an air stream. The device proved highly stable over a wide range of moisture contents. Slight variations in frequency were consistent with the variation predicted by the ideal gas behaviour of an air-water vapour mixture. The device is stable enough to be calibrated with dry air and corrected to any other humidity condition by application of the thermodynamic equations governing ideal gas mixtures.

Analytic Study on On-Line Model of Moisture in Hot Air Drying Process of Grain

2017 ◽  
Vol 872 ◽  
pp. 360-372
Author(s):  
Zhi Wei Mai ◽  
Bi Ying Wang ◽  
Chang You Li
Keyword(s):  
Moisture Content ◽  
Cross Flow ◽  
Drying Rate ◽  
Drying Process ◽  
Counter Flow ◽  
Drying Characteristics ◽  
Concurrent Flow ◽  
Content Ratio ◽  
Real Time Tracking ◽  
Drying Technology

This study aims to review variation pattern of moisture content ratio of grains in deep-bed drying process, guide the drying technology design, realize real-time tracking and regulation in drying process, improve the quality of drying process and reduce energy consumption. Based on the moisture diffusion model in thin layer drying process, the principle of mass conservation of deep drying process, state function and irreversible thermodynamics analytic method, we have established and solved basic equations of deep-bed drying of grains, obtained the moisture content ratio of grains and analysis formula of drying velocity distribution in processes of concurrent flow drying, counter flow drying, cross-flow drying and standing drying and resolved the sustained decreasing drying process of grains in the concurrent flow drying and extreme point of drying rate in the counter-flow drying. Under the same conditions of temperature, humidity and air output, the drying velocity in counter-flow drying significantly higher than that in the concurrent flow drying. It means the energy utilization effects in counter-flow drying is better than that in the concurrent flow drying. Drying characteristics of grains in cross-flow drying and standing flow drying are the same, while drying rates in inlet-air side and outlet-air side vary widely. It means that when the layer thickness is 0.5m and the moisture content is over 20%, the drying rate in outlet-air side is nearly zero and the drying uniformity is bad. Tests on 5HP-3.5 recirculation drier shows that maximum deviation between analytic value and measured value in deep drying process is 0.69% and the range scope is -0.27%-0.69%. From the drying characteristics of grains, deviations mainly come from instrument detection deviations. The analytic method has important significance for realizing real-time tracking and regulation in drying process, guiding drying technology design, reducing energy consumption, increasing drying rate and drying machine capacity.

scholarly journals Physical properties of safflower grains. Part I: Geometric and gravimetric characteristics

2017 ◽  
Vol 21 (5) ◽  
pp. 344-349 ◽  
Author(s):  
Elton A. S. Martins ◽  
André L. D. Goneli ◽  
Cesar P. Hartmann Filho ◽  
Munir Mauad ◽  
Valdiney C. Siqueira ◽  
...  
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Bulk Density ◽  
Surface Area ◽  
Initial Moisture Content ◽  
Volume Ratio ◽  
True Density ◽  
Geometrical Characteristics ◽  
Forced Air ◽  
Air Circulation

ABSTRACT Safflower is an oil crop and its oil can be used for food and industrial purposes. However, there is little information about the physical properties of these grains, which is important for the planning and execution of post-harvest stages. Thus, this study was carried out with the aim of evaluating the effect of drying on the main physical properties of safflower grains. Safflower grains were harvested with an initial moisture content of approximately 0.445 decimal d.b. (dry basis) and subjected to drying in an oven with forced air circulation at 40 °C, until the grains reached a final moisture content of 0.073 ± 0.008 decimal d.b. During the drying, bulk density and true density, porosity, thousand-grain mass, circularity, sphericity, projected and surface area, and surface-volume ratio were measured. Based on these results, it is concluded that all gravimetric and geometrical characteristics of safflower grains were reduced due to the reduction of moisture content, except for the surface-volume ratio.

scholarly journals Effect of steam thermal treatment on the drying process of Eucalyptus dunnii variables

CERNE ◽  
2013 ◽  
Vol 19 (4) ◽  
pp. 637-645 ◽  
Author(s):  
Elias Taylor Durgante Severo ◽  
Ivan Tomaselli ◽  
Fred Willians Calonego ◽  
André Luiz Ferreira ◽  
Lourival Marin Mendes
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Moisture Gradient ◽  
Steam Treatment ◽  
Drying Rate ◽  
Drying Process ◽  
Intermediate Layers ◽  
Eucalyptus Dunnii ◽  
Electric Oven ◽  
Heating Up

The aim of this study was to evaluate the effect of steam treatment prior to drying on the initial moisture content, moisture gradient, and drying rate in Eucalyptus dunnii Maiden wood. Boards were steamed at 100ºC for 3 h after 1 h of heating-up. Part of these boards was dried in a drying electric oven at 50ºC, and part was dried at kiln. The results showed that the steaming prior to drying of wood: (1) significantly reduced by 9.2% the initial moisture content; (2) significantly increased by 6.2% the drying rate; (3) significantly decreased by 15.6 and 14.8% the moisture gradient between the outer layer and the center of boards and between the outer and intermediate layers of boards, respectively. Steamed boards when dried in an oven showed drying rate of 0.007065 whereas in kiln were 0.008200 and 0.034300 from green to 17 and 17 to 12% moisture content, respectively. It was demonstrated that the steaming prior to drying can be suitable for reduces the drying times of this kind of wood.

scholarly journals Convective Thin-Layer Drying Characteristics of Sesame Seed

2012 ◽  
Vol 7 ◽  
pp. 55-62 ◽  
Author(s):  
O.U. Dairo ◽  
T.M.A. Olayanju
Keyword(s):  
Moisture Content ◽  
Thin Layer ◽  
Initial Moisture Content ◽  
Sesame Seed ◽  
Effective Diffusivity ◽  
Coefficient Of Determination ◽  
Drying Rate ◽  
Fundamental Information ◽  
Thin Layer Drying ◽  
Page Equation

Fundamental Information on Drying and Re-Wetting Characteristics of Agricultural Seeds Is Required in the Design and Aeration Systems as Well as in the Prediction of Drying Rate Using Various Mathematical Models. Thin-Layer Drying Experiments Were Conducted Using Air-Ventilated Oven to Simulate the Artificial Drying at Various Moisture Contents of Sesame Seed (6.9 to 18.2 % W.b) at Three Drying Temperatures of 40, 50 and 60OC. Five Drying Models Were Evaluated for the Thin-Layer Data. the Page Equation Fitted the Data Best, where Selection of the Best Model Was Obtained by Comparing the Coefficient of Determination (R2), the Standard Error of Moisture Content (SEM) and Mean Relative Percent Error (e) between the Experimental and Estimated Values. the Drying Rate of Sesame Seed under Drying Conditions Increased with Increased Temperature of Drying( 40 to 60OC) and Initial Moisture Content of Seed( 6.9, 11.5 and 18.2 % W.b). the Parameters “K” of the Page Model Increased with Increase in Temperature, while, Parameter ”n” Decreased with Temperature Increase and Increased with Increase in Moisture Content of Seed. the Effective Diffusivity Was Found to Be 2.32 X 10-11 M2s-1.

Experimental Research on Deep-Bed Drying Characteristics of Maize

2011 ◽  
Vol 308-310 ◽  
pp. 1586-1589
Author(s):  
Xing Zao Ma ◽  
Chang You Li ◽  
Li Li Zhang ◽  
Wen Hao Shen
Keyword(s):  
Optimal Design ◽  
Moisture Content ◽  
Experimental Research ◽  
Initial Moisture Content ◽  
Drying Rate ◽  
Drying Characteristics ◽  
Air Temperatures ◽  
Drying Efficiency

In this paper, the deep-bed drying rate was analyzed under different bed depths and air temperatures. It was found that the bed depth had a greater impact on the drying efficiency, and if the initial moisture content of maize and the ventilation temperature are higher, the effect would be much more notable. The results will provide a basis for optimal design of the deep-bed drying devices.

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.

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