Method for measuring moisture content in wood drying process and wood drying method

Abstract

The invention discloses a moisture content measuring method for a wood drying process and a wood drying method. The moisture content measuring method for the wood drying process and the wood drying method include: measuring an initial moisture content and initial weight of to-be-dried wood, and stacking the to-be-dried wood in a drying kiln; measuring temperature and wind speed of media flowing through two sides of the stacked to-be-dried wood, acquiring saturated vapor pressure of moist air according to dry-bulb temperature, acquiring relative humidity of the moist air according to temperatures of wet and dry bulbs, and finally acquiring density and moisture content of the moist air so as to obtain moisture contents of the to-be-dried wood at different times; according to the moisture contents of the to-be-dried wood, drying the to-be-dried word according to wood drying standards so as to obtain high-quality dry wood. The moisture content measuring method is precise, simple, low in input, applicable to any wood moisture content measurement, less in measuring parameters, simple in calculation, systematically stable, capable of overcoming the defects of large measuring error and narrow range of an electric measuring method and improving quality of solid wood plates, high in efficiency and low in cost.

Description

technical field [0001] The invention relates to a wood drying method, in particular to an online detection method of moisture content in the drying process of solid wood boards, and belongs to the field of wood drying. Background technique [0002] Wood veneer and board drying is a very important process in the wood processing process, and at the same time it is an important way to improve wood utilization and save forest resources. The drying process of wood is the process of water evaporation in wood. Due to the different relationship between various water in wood and the structure of wood, the properties of water in wood at each stage are different, and the properties of wood corresponding to this are different. Therefore, in the drying process of wood, it is necessary to reasonably control the evaporation process of water in the wood, and to increase the drying speed as much as possible on the premise of ensuring the drying quality. [0003] In the drying process of woo...

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Problems solved by technology

[0005] However, in the existing wood drying control research, the accuracy of the moisture content measured by the electrical measurement method is poor, and the error is relatively large, just because for different woods, the electrical resistance not only changes with the moisture content, but also varies with the moisture content. Temperature, tree species, wood density and grain direction are related, so there are many correction coefficients in the measurement process, and the accuracy is not high, especially for those wood whose properties are not well understood, it is more difficult to measure, and when the moisture content of wood is higher than fiber saturation When the temperature is 30%, there is free water inside the wood, and its electrical properties are equivalent to those of water, so the relationship between resistance and moisture content is not great, so the measured moisture content is inaccurate, and when the moisture content of wood is lower than At 5%, due to the large resistance value of the wood at this moment, it can reach 25 gigaohms, which makes the result of the electrical measurement method inaccurate, and the moisture content of the wood measured by the electrical measurement method is not accurate, resulting in Deviations from the wood drying program determined by the method will eventually lead to a decline in the quality of the dried wood

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