IDENTIFICATION OF THE CONVECTIVE PROCESS OF WOOD DRYING

P. V. Biley; I. A. Sokolovskyy; R. O. Rokun

doi:10.15421/40270914

Numerical Simulation of the Water Vapor Separation of a Moisture-Selective Hollow-Fiber Membrane for the Application in Wood Drying Processes

Membranes ◽

10.3390/membranes11080593 ◽

2021 ◽

Vol 11 (8) ◽

pp. 593

Author(s):

Nasim Alikhani ◽

Douglas W. Bousfield ◽

Jinwu Wang ◽

Ling Li ◽

Mehdi Tajvidi

Keyword(s):

Water Vapor ◽

Constant Temperature ◽

Hollow Fiber ◽

Hollow Fiber Membrane ◽

Vacuum Pressure ◽

Vapor Concentration ◽

Water Vapor Concentration ◽

Fiber Membrane ◽

Wood Drying ◽

Air Velocity

In this study, a simplified two-dimensional axisymmetric finite element analysis (FEA) model was developed, using COMSOL Multiphysics® software, to simulate the water vapor separation in a moisture-selective hollow-fiber membrane for the application of air dehumidification in wood drying processes. The membrane material was dense polydimethylsiloxane (PDMS). A single hollow fiber membrane was modelled. The mass and momentum transfer equations were simultaneously solved to compute the water vapor concentration profile in the single hollow fiber membrane. A water vapor removal experiment was conducted by using a lab-scale PDMS hollow fiber membrane module operated at constant temperature of 35 °C. Three operation parameters of air flow rate, vacuum pressure, and initial relative humidity (RH) were set at different levels. The final RH of dehydrated air was collected and converted to water vapor concentration to validate simulated results. The simulated results were fairly consistent with the experimental data. Both experimental and simulated results revealed that the water vapor removal efficiency of the membrane system was affected by air velocity and vacuum pressure. A high water vapor removal performance was achieved at a slow air velocity and high vacuum pressure. Subsequently, the correlation of Sherwood (Sh)–Reynolds (Re)–Schmidt (Sc) numbers of the PDMS membrane was established using the validated model, which is applicable at a constant temperature of 35 °C and vacuum pressure of 77.9 kPa. This study delivers an insight into the mass transport in the moisture-selective dense PDMS hollow fiber membrane-based air dehumidification process, with the aims of providing a useful reference to the scale-up design, process optimization and module development using hollow fiber membrane materials.

Download Full-text

Vortex Simulation of Rotor/Stator Interaction in Turbomachinery

Volume 1: Turbomachinery ◽

10.1115/98-gt-015 ◽

1998 ◽

Author(s):

Xian Hong Wu ◽

Mao Zhang Chen

Keyword(s):

Numerical Methods ◽

Flow Field ◽

Diffusion Process ◽

Numerical Method ◽

Outer Region ◽

Vortex Method ◽

Convective Process ◽

Rotor Stator Interaction ◽

Initial Description ◽

Lagrangian Frame

A new numerical method is presented in this paper to simulate rotor/stator interaction in turbomachinery by use of a vortex method based on a Lagrangian frame. The algorithm takes the result from steady solution as input, which can give an initial description of the unsteady disturbance flow field. To calculate the unsteady response to these disturbances, the Lagrangian vortex method is used to capture the convective process, and the deterministic vortex scheme to approximate the viscous diffusion process. The application of Baldwin-Lomax turbulence model in wakes is developed, so as to overcome the difficulties such as the much higher calculated viscosity in the outer region than that in the boundary regions, and the difficulty in continuously tracing moving wake centerlines encounted by other numerical methods. The agreement between the computational and experimental results is generally good. The sweeping characteristic of wakes, the influence of unsteadiness on incidence and the decaying features of unsteady velocities, pressure are included in the paper.

Download Full-text

Eucalyptus wood drying

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:2005123059 ◽

2005 ◽

Vol 123 ◽

pp. 327-330 ◽

Cited By ~ 2

Author(s):

A. Hakam ◽

A. Dikrallah ◽

B. Kabouchi ◽

A. Famiri ◽

M. Walia-Allah ◽

...

Keyword(s):

Wood Drying ◽

Eucalyptus Wood

Download Full-text

The Design of Temperature-Controlled of Wood Drying Remote Monitoring System Based on Fuzzy PID

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.391.347 ◽

2013 ◽

Vol 391 ◽

pp. 347-351

Author(s):

Yu Li Jun ◽

Shao Ying Liu ◽

Hui Wang ◽

Shu Qin

Keyword(s):

Monitoring System ◽

Remote Monitoring ◽

System Control ◽

Fuzzy Pid ◽

Monitoring And Control ◽

Wood Drying ◽

Fuzzy Pid Control ◽

Remote Communication ◽

Analysis And Design ◽

Remote Monitoring System

Effective temperature control plays a key role in remote monitoring of wood drying. This paper analysis and design a fuzzy PID control strategy under the monitoring and control system by establishing the mathematical model of wood drying system. It can realize the remote communication by using RS485 and achieve the actual operation of the monitoring system control. By experimental data and the experimental curve, the temperature of the system has good tracking effect which can be verified. It can achieve effective remote monitoring.

Download Full-text

System Identification of Wood Drying Process Based on ARMAX Model

Agricultural Sciences ◽

10.4236/as.2019.103020 ◽

2019 ◽

Vol 10 (03) ◽

pp. 241-248

Author(s):

Zheng Zhou ◽

Pinxiu Zhang ◽

Baofu Huai ◽

Liping Huang

Keyword(s):

System Identification ◽

Drying Process ◽

Wood Drying ◽

Armax Model

Download Full-text

How to use hand-held computers to evaluate wood drying.

10.2737/nc-rp-263 ◽

1985 ◽

Author(s):

Howard N. Rosen ◽

Darrell S. Martin

Keyword(s):

Wood Drying

Download Full-text

Numerical Study of Heat and Mass Transfer during the Thermal Drying of Tropical Woods

International Journal of Thermal and Environmental Engineering ◽

10.5383/ijtee.08.01.002 ◽

2014 ◽

Vol 08 (1) ◽

Keyword(s):

Water Content ◽

Thermophysical Properties ◽

Numerical Study ◽

Wood Quality ◽

Central Africa ◽

Industrial Process ◽

Self Control ◽

Heat Equations ◽

Wood Drying ◽

Tropical Woods

A sector of utilization and transformation of wood give much money at the countries of the central Africa region. If we want to increase these advantages, it is important to do locally the first and second transformations of wood. Self-control of the wood drying is necessary to ameliorate a wood quality and to preserve an art work doing in wood. In this article, we are modeling a drying of one piece of bete wood (Mansonia altissima) with dimensions are 1m of length and thickness is no more than 25cm. We have used a literature to obtain a mass and heat equations and the thermophysical properties of the present wood. We have considered some thermophysical properties that we are unkempt in the precedent work [1]. We have experimentally obtained a relationship between a density of this wood with a water content. The others thermophysical properties come from the literature [1,2]. We have simulated a wood drying in the constant conditions and in the conditions of the bete drying table established by CIRAD Organization. A sensibility study is doing to validate a modeling. Then, the present modeling explains temperature, mass fraction of the vapor in air and water content evolutions during the industrial process of drying. This modeling can to be used for to overhaul a drying table of bete wood and the others of tropical woods. This work uses a gaseous pressure can be used to explain the drying with the high temperatures conditions.

Download Full-text

Transient Free Convection from a Suddenly Heated Horizontal Wire

Journal of Heat Transfer ◽

10.1115/1.3450825 ◽

1978 ◽

Vol 100 (3) ◽

pp. 423-428 ◽

Cited By ~ 20

Author(s):

J. R. Parsons ◽

J. C. Mulligan

Keyword(s):

Heat Transfer ◽

Steady State ◽

Rayleigh Number ◽

Heat Rate ◽

Wheatstone Bridge ◽

Step Change ◽

Simultaneous Observation ◽

State Data ◽

Convective Process ◽

Horizontal Wire

Experimental data are presented for the transient free convective heat transfer from a horizontal wire in air subjected to a step change in heat rate. An unbalanced Wheatstone bridge is described which allows simultaneous observation of wire temperature and heat rate, under transient as well as steady-state conditions. An “overshoot” of the steady-state is shown to occur in the transient decay of the Nusselt number, and the occurrence, magnitude, and duration of this phenomenon is shown to depend upon the Rayleigh number. Simple stability theory is shown to explain the delay in the convective process which is associated with the overshoot in heat transfer. Steady-state data are also presented and are shown to agree well with proposed low Rayleigh number correlations.

Download Full-text