Method for measuring thickness of heat-and-mass transmission thin layer on timber surface in drying process

Abstract

The invention discloses a method for measuring the thickness of a heat-and-mass transmission thin layer on a timber surface in drying process. The method comprises the steps that a temperature t medium and flow rate v medium of a drying medium are measured; a temperature t timber and pressure R timber of the medium above the timber surface are measured once at certain interval in the thickness direction starting from the timber surface, and a corresponding medium flow rate v timber is computed; the ratios of the temperature and flow rate of the medium above the timer surface and that of an indoor drying medium are compared until the n measured t timber n / t medium n>= 0.99 and v timber n / n medium>= 0.99, and the distance moving the in the timber thickness direction is the thickness ofthe heat-and-mass transmission thin layer on the timber surface in the drying process. The method has the advantages that the measuring of the thickness of the heat-and-mass transmission thin layer onthe timber surface is accurate, the precision is high, the heat-and-mass transmission thin layer is improved in the drying process of timbers, data support is provided for improving the drying quality of the timbers, and better theoretical supports are provided for the enhancement of the heat and moisture transmission on the surface of the timber and the acceleration of the drying rate of the timbers.

Description

technical field [0001] The invention relates to a method and a device for wood drying treatment, in particular to a method and a device for measuring the thickness of a thin layer of heat and mass transfer on a wood surface during the wood drying process, and belongs to the field of wood thermal processing. Background technique [0002] Wood drying is an important link in the wood product processing process, and its energy consumption accounts for 40-70% of the wood product processing process. Improving wood drying efficiency and reducing drying energy consumption have become urgent problems in the wood processing industry. [0003] At present, in order to improve the drying rate of wood, the invention patent 201410424968.7 provides a treatment device for improving the drying rate of wood and a method for drying wood by using the device. The present invention discloses a pretreatment device and a treatment method for improving the drying rate of wood. The device includes a w...

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Problems solved by technology

[0010] The purpose of the present invention is to improve only the wood structure itself in the existing wood drying process, while ignoring the hindrance effect of the wood surface heat and mass transfer thin layer on the heat and moisture transfer in the wood drying process, which affects the wood drying speed and quality The technical defect is to provide a method for measuring the thickness of the thin layer of heat and mass transfer on the surface of wood during the drying process. The thickness of the thin layer of heat and mass transfer on the surface of wood measured by the method of the present invention is accurate, and the accuracy of the thickness is high, which is for improving the heat and mass transfer during the drying process of wood. It provides data support for improving wood drying quality, and provides good theoretical guidance for accelerating wood drying rate and improving wood drying quality.

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