Location:Home > Engineering science > Forest Engineering > Wood Science and Technology > The Research on Water Content of Wood During High Temperature Treatment Process
Details
Name

The Research on Water Content of Wood During High Temperature Treatment Process

Downloads: []
Author
Tutor: WeiXiang
School: Central South University of Forestry Science and Technology
Course: Wood Science and Technology
Keywords: Timber,Moisture adsorption,Equilibrium moisture content,Mathematical model,Inter
CLC: S781
Type: Master's thesis
Year:  2008
Facebook Google+ Email Gmail Evernote LinkedIn Twitter Addthis

not access Image Error Other errors

Abstract:
In recent years, with more and more timber in the widespread use of high-temperature drying and high temperature and high humidity condition in the various fields of application, to investigate the condition of the moisture content of the wood in the high-temperature region, and its moisture adsorption mechanism is very necessary, which reveals the high temperature and humid The physical properties of the timber in the state, especially in the wood drying process rheological properties and humidity treatment has important practical significance. This study uses self-developed device, using the method of direct readings were done Masson pine, cryptomeria camaldulensis three wood moisture adsorption experiments in high temperature, the temperature range of 100 ”ę to 140 ”ć C and a relative humidity range of 10% to 100%. The results mainly includes the following five sections: (1) the appropriate bath system can constitute the working space of a high temperature under the condition of constant temperature and humidity, and the vacuum system can eliminate the interference of other gases include nitrogen, including the accurate measurement of the timber on the adsorption of moisture. (2) The timber 100 ”ę above and 100 ”ć C or less, the adsorption isotherm to render the same trends, and the equilibrium moisture content is reduced as the temperature increases, the increase of relative humidity increases. However, when the relative humidity is greater than 95%, the equilibrium moisture content at a high temperature significantly increases, and increases as the temperature increases. 100 ”ć C or more type of adsorption isotherm does not belong to the second category, \their chemical composition (cellulose, hemicellulose and lignin, etc.), cellulose crystallinity, and the density of the cell wall is caused. (3) use of the experimental results of the the BET models and Haillwood-Horrobin model test, the two models predictive value the monolayer adsorption when measured value is very consistent, and multilayer adsorption and capillary condensation deviate from great, especially with the significantly elevated temperature, deviation is more serious. Relatively speaking Haillwood-Horrobin model than the BET model is slightly better, but both models are no longer suitable as a high temperature wood moisture adsorption model. (4) based on the relationship between the wood equilibrium moisture content, temperature and relative humidity, and the use of Matlab software were established masson pine, cryptomeria and the camaldulensis mathematical model, the temperature range of 100 ”ę to 140 ”ć C, a relative humidity range of 10-95%. Learned the test of three models: the model predicted and measured values ??fit better than the the BET models and Haillwood-Horrobin model is good, and the model is the most appropriate of Cryptomeria, followed by camaldulensis and Pinus massoniana somewhat less. Inspection Cryptomeria model temperature of 105 ”ć C, 115 ”ć C, 125 ”ć C and 135 ”ę of the predicted values ??and the measured values ??of the equilibrium moisture content is relatively good anastomosis. It can be obtained by experimental equilibrium moisture content of each tree species under certain temperature and relative humidity, and then build mathematical models for each species based on the experimental data, and the use of mathematical models can get the balance of each species in the corresponding temperature and relative humidity moisture content. (5) using MATLAB software can interpolate the experimental data processing, learned by examining the correlation between the predicted and measured values ??of the interpolation process, so this line of thinking is correct. It can be obtained by experimental equilibrium moisture content of each species under certain temperature and relative humidity, then interpolation processing using MATLAB software on these experimental data, and finally set up a database, the database can be any species at any temperature and relative humidity of the equilibrium moisture content.
Related Dissertations
Last updated
Sponsored Links
Home |About Us| Contact Us| Feedback| Privacy | copyright | Back to top