Initial Moisture Content and Density and Drying Rate of Three Pine Species Growing in the Natal Midlands

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).

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

CERNE ◽

10.1590/s0104-77602013000400014 ◽

2013 ◽

Vol 19 (4) ◽

pp. 637-645 ◽

Cited By ~ 8

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.

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Convective Thin-Layer Drying Characteristics of Sesame Seed

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.7.55 ◽

2012 ◽

Vol 7 ◽

pp. 55-62 ◽

Cited By ~ 1

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.

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Experimental Research on Deep-Bed Drying Characteristics of Maize

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.308-310.1586 ◽

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.

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Electrically enhanced drying of white champignons

Proceedings of 21th International Drying Symposium ◽

10.4995/ids2018.2018.7318 ◽

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.

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Evaluation of the Performance of a Custom-Made Fluidized Bed Drying System

Applied Engineering in Agriculture ◽

10.13031/aea.12909 ◽

2018 ◽

Vol 34 (6) ◽

pp. 1027-1037 ◽

Cited By ~ 1

Author(s):

Sammy S. Sadaka ◽

Kaushik Luthra ◽

Griffiths G. Atungulu

Keyword(s):

Aspect Ratio ◽

Moisture Content ◽

Fluidized Bed ◽

Initial Moisture Content ◽

Small Scale ◽

Drying Rate ◽

Furnace Temperature ◽

Fluidized Bed Dryer ◽

Custom Made ◽

Drying System

Abstract. Laboratory and farm-scale fluidized bed dryers are not available to purchase. Additionally, a deliberation is presently continuing regarding the beneficial and damaging effects of drying grain in a fluidized bed. Therefore, the goal of this research was to develop and test a custom-made small-scale fluidized bed dryer, suitable for moderate farms and capable of drying small and large size grains from high moisture content to a safe storage moisture content. The customary fluidized bed dryer was developed and constructed in the Rice Research and Extension Center, Stuttgart, Arkansas. The fluidized bed dryer was used to dry wheat from an initial moisture content of 23.3% db. The effects of the aspect ratio (bed height to bed diameter ratio) of 2, 3, and 4 m/m, the furnace temperature of no heat, 100°C, 150°C, and 200°C and drying duration of 10, 20, 30, 40, 50, and 60 min on the wheat moisture content, drying rate, and dryer efficiency were investigated. The lowest wheat moisture content of 16.3% db was observed at the lowest aspect ratio of 2 m/m, the highest furnace temperature of 200°C, and the longest drying duration of 60 min. Conversely, the highest wheat moisture content of 19.0% db was observed at the highest aspect ratio of 4 m/m, and the no heat condition. The drying rate of 0.47%/min was observed at the lowest aspect ratio of 2 m/m and the furnace temperature of 200°C after 10 min. The maximum dryer efficiency of 63.2% was achieved at the aspect ratio of 4 m/m, the furnace temperature of 200°C. Two empirical models were developed to predict the moisture content of wheat and the dryer efficiency as affected by the aspect ratio, the furnace temperature and the drying duration with the adjusted coefficient of determination of 0.91 and 0.88, respectively. Although, the developed fluidized bed dryer is a lab-scale system, the experimental results provided an exceptional indication to scale up the drying system to dry grains. Keywords: Dryer efficiency, Drying rate, Fluidized bed, Moisture content, Wheat-drying.

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Drying Rate of Grain Maize

Acta Technologica Agriculturae ◽

10.2478/ata-2013-0008 ◽

2013 ◽

Vol 16 (2) ◽

pp. 31-34

Author(s):

Ivan Vitázek ◽

Peter Vereš

Keyword(s):

Energy Consumption ◽

Moisture Content ◽

Initial Moisture Content ◽

Preventive Measure ◽

Moisture Loss ◽

Graphical Form ◽

Drying Rate ◽

Atmospheric Conditions ◽

Drying Time ◽

Thermal Drying

Abstract Maize is harvested after reaching maturity when its moisture content generally ranges from 30 % to 34 %, while the optimum moisture for storage is around 14-15 %. This moisture is usually achieved by thermal drying. Apart from initial moisture, the total drying time is affected by the temperature of the drying environment, atmospheric conditions and properties of the dried material. The present paper provides a description of the process of moisture loss and subsequent drying rate of grain maize from various growers. Obtained results are processed in a tabular and graphical form. After 30 minutes of drying, all the maize samples (10 samples two times in total) reached a moisture of 14 % and less, whereas 6 samples already after 20 minutes of drying. The rate of moisture loss was proportional to the initial moisture content. The drying of grain maize is considered one stage of the technological procedure in post-harvest treatment. Moreover, it is an essential preventive measure for wet harvest. Contemporary technologies of maize drying in modern dryers favourably influence the energy consumption in the process while maintaining the qualitative parameters of the dried material.

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Application of basic drying theory to determine drying mass constants of selected seafoods

Global Journal of Engineering and Technology Advances ◽

10.30574/gjeta.2021.7.1.0062 ◽

2021 ◽

Vol 7 (1) ◽

pp. 137-143

Author(s):

Orua Okon Antia ◽

William Adebisi Olosunde ◽

Emem Orua Antia

Keyword(s):

Food Security ◽

Moisture Content ◽

Model Equation ◽

Initial Moisture Content ◽

Data Bank ◽

Drying Rate ◽

Storage Space ◽

Drying Time ◽

Experimental Values ◽

Drying Curve

The drying of seafood could ensure increase in life span, minimization of storage space, ease of transportation, etc of the product. It is therefore, necessary to dry and know when to stop drying at an appropriate moisture content that would minimize associated challenges in promoting food security. In this study, selected sea foods, such as prawn and oyster were obtained and then dried to determine their drying mass constants using model equation developed based on basic drying principle. The value of the constants obtained would provide data bank to facilitates prediction of mass of the drying material at given time that would correspond to any desired moisture content, provided the initial moisture content of the material is known. The plots of moisture content against drying time, drying rate against drying time and moisture content versus were carried out. It was observed that increase in size of the drying material increased the drying time. Moreover, the drying rate curve resembles a typical drying curve. Hence, the experimental values obtained are reliable. Technical analysis showed that the drying mass constants for prawn and oyster are 0.2950 ± 0.0119 and 0.2453 ± 0.0476, respectively.

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