Non-Deterministic Description of Wood Radio Frequency Vacuum Drying

Holzforschung ◽  
2003 ◽  
Vol 57 (1) ◽  
pp. 88-94 ◽  
Author(s):  
D. Elustondo ◽  
A. Koumoutsakos ◽  
S. Avramidis
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Standard Deviation ◽  
Moisture Content ◽  
Radio Frequency ◽  
Western Hemlock ◽  
Vacuum Drying ◽  
Drying Process ◽  
Stochastic Parameters ◽  
Deterministic Description

Summary A numerical method is proposed to predict the stochastic dispersion of data that unavoidably occurs in a real drying process. The method is based on the use of discrete frequency distribution curves to predict a random variation on some parameters of the process and is applied to the case of radio frequency vacuum (RFV) drying of wood. Experimental data of RFV drying of western hemlock timbers were used to obtain the numeric values of the stochastic parameters and their standard deviation. A mathematical model was designed to simulate the final moisture content dispersion on hypothetical examples. Results were quantified using three indices: average, range and standard deviation.

scholarly journals A Mathematical Model for Predicting the Winnowing Efficiency of Bambara Groundnut Sheller

2020 ◽  
Vol 5 (2) ◽  
pp. 225-228
Author(s):  
Inimfon Samuel Ossom ◽  
Akindele Folarin Alonge ◽  
Kingsley Charles Umani ◽  
Edidiong J. Bassey
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Moisture Content ◽  
Model Equation ◽  
Model Simulation ◽  
Least Square Method ◽  
Bambara Groundnut ◽  
Least Square ◽  
Predicted Model ◽  
Experimental Values

A mathematical model for predicting the winnowing efficiency of bambara groundnut sheller was developed. The regression equation for model simulation was developed using Least Square Method. The model was verified and validated by fitting it into established experimental data from winnowing efficiency of already existed Bambara groundnut sheller. The result revealed that the fitted model correlated well with the experimental data with R-square value of 0.99. The winnowing efficiency obtained from the predicted model was approximately the same values with the experimental values. Therefore, the model equation was considered to be reasonably good for predicting the winnowing efficiency of bambara groundnut sheller for known values of moisture content and blower speed.

scholarly journals Mathematical Model for Solar Drying of Grains

2019 ◽  
pp. 1-18
Author(s):  
A. O. Fagunwa ◽  
O. A. Aregbesola ◽  
M. O. Faborode
Keyword(s):  
Mathematical Model ◽  
Thermal Properties ◽  
Moisture Content ◽  
Climatic Conditions ◽  
Drying Rate ◽  
Solar Drying ◽  
Drying Process ◽  
Complex Procedure ◽  
Unique Method ◽  
Complex Phenomena

Mathematical modeling of drying process is a complex procedure that should be carefully done. Moreso, model for solar drying, which is a unique method of drying due to constant fluctuation in the climatic conditions, requires complete integration of the complex phenomena that are involved for accurate prediction of moisture content and drying rate. A mathematical model was developed from heat and mass balance equation considering the physical and thermal properties of the grain, meteorological factors and convective heat transfer during solar drying of grains. The data obtained from the model was compared with experimental results obtained using a solar dryer to dry five selected grains – cowpea, soyabean, groundnut, maize and sorghum at airflow rates of 0.22 m/s, 0.76 m/s and 0.94 m/s. The results from statistical analysis and regression analyses used to compare the results showed that the model is adequate in predicting the moisture content and drying rate of the selected grains as well as other agricultural products with closer physical and thermal properties.

Drying of Industrial Hollow Ceramic Brick: A Numerical Analysis Using CFD

2019 ◽  
Vol 391 ◽  
pp. 48-53 ◽  
Author(s):  
Morgana Vasconcellos Araújo ◽  
R.S. Santos ◽  
R. Moura da Silva ◽  
J.B. Silva do Nascimento ◽  
W.R. Gomes dos Santos ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Moisture Content ◽  
Dynamics Analysis ◽  
Unit Operation ◽  
Drying Process ◽  
Ceramic Brick ◽  
Temperature Distributions ◽  
Computational Fluid Dynamics Analysis ◽  
Good Agreement

The drying process can be defined how unit operation for removing water of one moist solid to an unsaturated gaseous phase due to heat transfer. Numerical simulation emerges like a tool that allows the reproduction of drying experiments using computers and suitable softwares. In this sense, this works aims to predict drying process of an industrial hollow ceramic brick inside the kiln using computational fluid dynamics analysis. For one drying temperature of 60°C, results of the drying and heating kinetics, and moisture content, velocity and temperature distributions are shown and analyzed. A comparison between predicted and experimental data of the moisture content and temperature of the brick along the process was done and a good agreement was obtained.

scholarly journals Process optimisation of vacuum drying of onion slices

2011 ◽  
Vol 29 (No. 6) ◽  
pp. 586-594 ◽  
Author(s):  
J. Mitra ◽  
S.L. Shrivastava ◽  
P.S. Rao
Keyword(s):  
Moisture Content ◽  
Numerical Technique ◽  
Colour Change ◽  
Vacuum Drying ◽  
Slice Thickness ◽  
Drying Process ◽  
Rehydration Ratio ◽  
Drying Temperature ◽  
Treated Sample ◽  
Full Factorial

Dehydration of untreated and pre-treated onion slices under vacuum was optimised using the response surface methodology. The effects of the drying temperature (50&ndash;70&deg;C), slice thickness (1&ndash;5 mm), and treatment (5% NaCl and 0.2% K<sub>2</sub>S<sub>2</sub>O<sub>5</sub>) were observed on the responses, viz. final moisture content, colour change, flavour content, and rehydration ratio of the dehydrated onion slices. Full factorial design was employed for the analysis. Optimisation of the vacuum drying process was achieved based on the criteria of maximum flavour retention, 3&ndash;3.5% db moisture content, acceptable colour, and rehydration ratio using numerical technique. The optimum condition for the treated sample was found at 58.66&deg;C drying temperature and 4.95 mm slice thickness. Optimum values of the response parameters, namely the moisture content, colour, flavour content, and rehydration ratio were obtained as 3.5% d.b., 30.33 OI/g dried sample; 4.35 &mu;mol/g dried sample and 4.82, respectively.

RADIO FREQUENCY VACUUM DRYING OF WOOD. I. MATHEMATICAL MODEL

2001 ◽  
Vol 19 (1) ◽  
pp. 65-84 ◽  
Author(s):  
Anastasios Koumoutsakos ◽  
Stavros Avramidis ◽  
Savvas G. Hatzikiriakos
Keyword(s):  
Mathematical Model ◽  
Radio Frequency ◽  
Vacuum Drying

scholarly journals Determination of Temperature of Components of Cotton-Raw Material in a Drum Dryer with a Constant

2021 ◽  
Vol 939 (1) ◽  
pp. 012052
Author(s):  
A Z Mamatov ◽  
A K Usmankulov ◽  
I Z Abbazov ◽  
U A Norboyev ◽  
E T Mukhametshina
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Comparative Analysis ◽  
Boundary Value Problem ◽  
Parabolic Type ◽  
Raw Material ◽  
Drying Process ◽  
Moisture State ◽  
Type Boundary

Abstract This article solves one parabolic-type boundary value problem for determining the heat-moisture state of raw cotton in drum dryers at a constant air temperature. Numerical results are obtained by the Bubnov – Galerkin method of the problem under consideration, a comparative analysis is carried out with experimental data. It is shown that the proposed mathematical model and its numerical algorithm adequately describe the drying process of raw cotton.

scholarly journals Drying kinetics of jatropha seeds

Revista CERES ◽  
2012 ◽  
Vol 59 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Valdiney Cambuy Siqueira ◽  
Osvaldo Resende ◽  
Tarcísio Honório Chaves
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Mathematical Models ◽  
Dry Matter ◽  
Initial Moisture Content ◽  
Drying Process ◽  
Drying Time ◽  
Mean Error ◽  
Federal Institute ◽  
Jatropha Seeds

Given the necessity of developing jatropha cultivation equipment, this work adjusted different mathematical models to experimental data obtained from the drying of jatropha seeds submitted to different drying conditions and selected the best model to describe the drying process. The experiment was carried out at the Federal Institute of Goiás - Rio Verde Campus. Seeds with initial moisture content of approximately 0.50 (kg water/kg dry matter) were dried in a forced air-ventilated oven, at temperatures of 45, 60, 75, 90 and 105°C to moisture content of 0.10 ± 0.005 (kg water/kg dry matter). The experimental data were adjusted to 11 mathematical models to represent the drying process of agricultural products. The models were compared using the coefficient of determination, chi-square test, relative mean error, estimated mean error and residual distribution. It was found that the increase in the air temperature caused a reduction in the drying time of seeds. The models Midilli and Two Terms were suitable to represent the drying process of Jatropha seeds and between them the use of the Midili model is recommended due to its greater simplicity.

Modeling and Simulation of a Co-current Rotary Dryer

2016 ◽  
Vol 12 (2) ◽  
pp. 189-194 ◽  
Author(s):  
Zhi-gang Huang ◽  
Yun-xuan Weng ◽  
Nan Fu ◽  
Zong-qiang Fu ◽  
Dong Li ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Moisture Content ◽  
Mathematical Models ◽  
Modeling And Simulation ◽  
Air Temperature ◽  
Good Accuracy ◽  
Rotary Dryer ◽  
Simulation Results ◽  
The Mathematical Model

Abstract Mathematical models including mass and energy conservation were developed in order to predict the outlet particles temperature and moisture. As the inlet air temperature increased, the outlet particles temperature increased as well and the outlet particles moisture decreased quickly. The outlet particles temperature and moisture changed a little as a function of the speed of rotation at the low inlet air temperature, while the outlet particles temperature and moisture increased very apparently with the speed of rotation increased at the high inlet air temperature. The error of the simulation results compared to the experimental data showed good accuracy for particles temperature and moisture content. The mathematical model performs well to predict the outlet particles temperature and moisture content.

Impregnation and Drying Schedule of Eucalyptus Wood

2011 ◽  
Vol 71-78 ◽  
pp. 860-863
Author(s):  
Guo Feng Wu ◽  
Qian Lang ◽  
Shu Ping Song ◽  
Jun Wen Pu
Keyword(s):  
Standard Deviation ◽  
Moisture Content ◽  
Wood Fiber ◽  
Basic Density ◽  
Untreated Wood ◽  
Drying Rate ◽  
Hot Press ◽  
Drying Process ◽  
Eucalyptus Wood ◽  
Wood Composition

The aim of this research was to define a rapid and simple test that would indicate the probable performance of a pretreated wood species in a hot-press drying process and the kiln schedule. The drying rate (mass/time) and the remaining mass of water were measured at different moisture intervals. The moisture of timber decreased rapidly and the drying rate was 3.7% per day in the early five days. The timbers were B grade after drying used the hot-press drying kiln in 16 days. The moisture content of timber reached 9.20% after the drying process with the standard deviation of 0.92%. The gradient of the moisture content was 3.40%. The moisture content standard deviation in the thickness of timber was 2.70% and the residual stress was 1.38%. The mechanical properties of impregnation wood improve significantly compared to the untreated wood. The basic density of impregnation wood improved by 17.1%, the over-dried density increased to 0.55 g·cm-3 from 0.49 g·cm-3. The scanning electron microscopy explained the wood modifier has been permeated into the wood fiber which reacted with the wood composition.

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