System and method for drying green woods

Abstract

A system for drying a large quantity of wood efficiently, which includes: a wood drying room capable of being sealed; a combustion-gas generator provided with an air-inlet conduit for introducing fresh air for combustion use into a combustion chamber provided in a lower area of the combustion-gas generator; a combustion-gas supplying passage extending from an upper area of the combustion-gas generator to an upper area of the wood drying room; an exhaust-gas discharging conduit extending from a bottom area of the wood drying room to a chimney; a combustion-gas recovery conduit extending from the bottom area of the wood drying room to the combustion-gas generator, and a gas flow-rate control unit provided in at least one of the exhaust-gas discharging conduit and the combustion-gas recovery conduit.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a system for drying wood, and more particularly to a thermal dry stem for drying green wood, green bamboo and other green plants (which have been harvested) to produce, in short periods of time, dried wood, dried bamboo and other dried plants which have been stabilized in their water content.2. Description of the Prior ArtAfter harvest, green wood (and the like) are rich in water content, and usually carry many insects and their eggs. Consequently, in producing lumbers for building use and / or furniture use, it is usual to dry the green wood and chemically treat the same to kill the insects and theireggs.In drying process, the green wood is hitherto subjected to natural seasoning in which it is necessary to leave the green wood as it is for a long period of time, for example, three to five years in a wood yard. During this long period of time, it is necessary for workers of the wood yard to frequentl...

AI Technical Summary

Benefits of technology

In an efficient drying operation of the green woods in the wood drying system of the present invention, it is necessary for the system to produce a combustion gas with substantially no oxygen content. In addition, it is not desirable for a temperature of the combustion gas to excessively increase. Therefore, the circulation of the combustion gas in part is desirable in the system of the present invention. By circulating a part of the combustion gas through the system of the present invention, it is possible for the system to recover vapor and volatile materials from the combustion gas before the gas is discharged from the system through the chimney. The thus recovered volatile materials are subjected to combustion again and burned in the system before they are discharged to the atmosphere through the chimney, which combustion contributes towards the solution of air pollution (caused by the volatile materials contained in the combustion gas) and also contributes to cost saving since the volatile materials may be utilized as fuels in the system of the present invention.

Problems solved by technology

However, leaving the wood for such long period of time in the wood yard results in a poor investment, and is further disadvantageous in preventing the woods from being attached by insect.

However, dried wood produced by conventional quick drying processes suffer disadvantages in that the wood is not prevented from cracking; and absorbing moisture which causes distortion of the woods, as in the case of dried wood produced by natural seasoning.

These Japanese Patent Laid-Open documents also disclose a system for carrying out a process which is; however, poor in treatment efficiency of the woods.

In this process, when large quantity of green wood is housed in the treatment chamber in order to improve the treatment efficiency, the dried wood obtained through the process tend to vary in water content, which makes it impossible to stabilize the products (or dried wood) in quality.

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