JP3986609B2 - Wood drying equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, in order to dry the wood, the drying costs as well as significant savings relates dry 燥装 location of wood so as to prevent cracking during drying of the wood.
[0002]
[Prior art]
In general, wood is easy to process and has excellent electrical and thermal insulation properties, and is excellent as various materials. However, it is necessary to dry before use because it is distorted due to shrinkage and expansion due to moisture absorption and desorption.
[0003]
When wood is subjected to chemical processing / chemical modification treatment such as bleaching, coloring, antiseptic, insecticidal, ant-proofing, flame retardant, resin impregnation, etc., it is necessary to dry before treatment in order to improve the effect and efficiency of the treatment. .
[0004]
For drying wood, natural drying in which the wood is placed in a natural environment and drying, dehumidification drying in which the wood is placed in a drying room and dried using a dehumidifier, and reduced-pressure high-frequency heating drying using high-frequency heating under reduced pressure Etc. with artificial drying.
[0005]
[Problems to be solved by the invention]
However, the natural drying described above is relatively easy to dry to some extent, but further drying requires a very long time (several months). Artificial drying does not require as much time as natural drying, but it still requires a considerable amount of time (2 to 3 weeks), and during that time, dehumidifiers, high-frequency heating devices, etc. must continue to operate throughout the day and night. Running costs, labor costs, management costs, etc. increase and the drying cost is high, and since the inner core material part contains more water than the outer sapwood part, only the sapwood part suddenly At present, drying of the core part is delayed, and tensile stress is generated in the sap part and compressive stress is generated in the core part, resulting in many cracks and distortions.
[0006]
The present invention has been made in view of the above problems, and has been made to improve and remove the problem. The object of the present invention is to drastically shorten the drying time and prevent cracking and distortion during drying. There is.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention achieves the above-mentioned object by means of a draft tube whose cross-sectional area ratio gradually decreases from a carry-in entrance through which the heat-softened wood passes through to the carry-out exit, or a vertically opposed compression through which the wood passes. A draft device comprising a roller or a lattice conveyor, and a cross-sectional area which is arranged on the carry-out side of the draft device and which is larger than the cross-sectional area of the wood in the carry-out portion of the draft device and slightly smaller than the original cross-sectional area of the wood A cylindrical drying case having a mesh shape or a porous shape and good air permeability, and the wood is forcibly pushed into the draft tube or supplied between the compression roller or the lattice conveyor And a means for drying the wood .
[0008]
According to the present invention, the air permeability inside the wood is improved by the damaging action of the pits connecting the conduits inside the wood and the conduits that are generated when the moisture contained in the wood is squeezed out. Since the moisture content of timber is greatly reduced, the drying time can be greatly shortened and the drying cost can be greatly reduced. Also, growth strain is removed by heating with warm water or steam, etc., and the moisture content of each part is made uniform by compression, so that it can be dried in a short time, and a drying case with good ventilation It is possible to prevent cracking at the time of drying by housing in a slightly compressed state. Further, by heating with warm water, water vapor, high frequency or the like before drying, warping and madness can be prevented.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a wood drying method and apparatus according to the present invention will be described with reference to FIGS.
[0010]
In the method of the present invention, first, wood is heated and softened with warm water, steam, high frequency or the like. For example, as shown in FIG. 1, high temperature (about 80 to 90 ° C.) warm water or steam is supplied into the treatment tank (2) containing the wood (1), so that the wood (1) is warm water or steam. By heating for a predetermined time (about 30 to 120 minutes), the internal temperature of the wood (1) rises and softens.
[0011]
Next, as shown in FIG. 2, the heat-softened wood (1) is forcibly squeezed out with a draft device (3), and this is accommodated in a dry case (4) with good air permeability. .
[0012]
The draft device (3) shown in FIG. 2 has a cylindrical shape having a quadrangular, circular, hexagonal or other polygonal cross-sectional shape according to the cross-sectional shape of the wood (1). ) And the draft tube (5) formed so that the cross-sectional area ratio is gradually narrowed to about 1/2 to 1/3, and the draft tube (5) is disposed to face the outlet (5a), The piston rod (6a) comprises a pushing cylinder (6) such as a hydraulic cylinder in which a pushing plate (6b) is fixed to the tip of the piston rod (6a), and the heated and softened wood (1) is supplied with an appropriate supply means (not shown). ), The piston rod (6a) of the pushing cylinder (6) is extended to allow the pushing plate (6b) to be extended between the draft tube (5) and the pushing plate (6b) of the pushing cylinder (6). By moving forward, the wood (1) is brought into the carry-in port ( a) is forced into the draft tube (5), and the wood (1) is sequentially compressed so that the cross-sectional area ratio is about 1/2 to 1/3, and the water contained therein is squeezed out. The wood (1) is accommodated in the drying case (4) from the outlet (5b) of the draft tube (5).
[0013]
When the wood (1) is compressed by the draft device (3) so that the cross-sectional area ratio is about 1/2 to 1/3, the conduits inside the wood (1) are connected to each other. Since the pits are destroyed, the moisture of the wood (1) is almost squeezed out so that the moisture content of each part becomes uniform, and the ventilation of the wood (1) is improved.
[0014]
The draft device (3) is replaced with the draft tube (5), as shown in FIG. 5 (a), as shown in the compression rollers (8) (8) facing up and down, and as shown in FIG. 5 (b), It is also possible to use lattice conveyors (9) and (9) that face each other vertically.
[0015]
The drying case (4) has a cylindrical shape made of resin or metal having a square, circular, hexagonal or other polygonal cross-sectional shape according to the cross-sectional shape of the wood (1). For example, as shown in FIG. As shown in FIG. 3 (b), the water contained in the wood (1) is easy to evaporate. The dry case (4) is formed so that its cross-sectional area is slightly smaller than the original cross-sectional area of the wood (1), and the wood (1) is accommodated in a slightly compressed state. For example, when the wood (1) is 105 × 105 (mm), the drying case (3) is set to about 103 × 103 (mm).
[0016]
Next, the wood (1) housed in the drying case (4) is dried by squeezing out moisture with the draft device (3). For example, as shown in FIG. 4, in a state where one or several drying cases (4) containing wood (1) are sandwiched between a pair of hot plates (7) (7), the pair of hot plates (7) (7) is heated with an appropriate heating means to heat the wood (1) through the drying case (4), or a high frequency current is passed through the pair of hot plates (7) (7) The wood (1) is dried by high-frequency heating 1) to evaporate water remaining in the wood (1).
[0017]
As another drying method, the drying case (4) containing the wood (1) is carried into a normal pressure, high pressure or vacuum drying chamber, where the wood (1) is dehumidified, hot air or the like. Dry to dryness.
[0018]
When the wood (1) is dried in this way, the wood (1) is somewhat reduced, so that the wood (1) can be easily extracted from the drying case (3), and the drying of the wood (1) is completed.
[0019]
As in the present invention, first, the wood (1) is softened by heating with warm water or steam, high frequency, etc., and the wood (1) is squeezed out almost by the draft device (3), If the dry case (4) is stored in a dry case (4) with good air permeability, and the wood (1) is dried by subjecting the dry case (4) to drying by high-frequency heating or hot air heating, the moisture is squeezed out. The internal air permeability of the wood (1) is improved by the breaking action of the pits connecting the conduits inside the wood (1) generated at the same time, and the moisture content of the wood (1) in the initial drying stage is improved. Since it is greatly reduced, the wood (1) can be dried to a desired dry state within one day, and the drying time can be greatly shortened.
[0020]
Further, the wood (1) can be prevented from distortion during drying by removing growth distortion by heating with warm water or steam, and the moisture contained in the inside is almost squeezed out by compression, so that the moisture content of each part is made uniform. Thereby, there is no difference in the moisture content between the sapwood part and the core part, and cracking during drying can be prevented.
[0021]
In the above embodiment, the wood (1) is dried in the drying case (4) while squeezing the moisture contained in the wood (1) with the draft device (3). If necessary, the wood (1) accommodated in the drying case (4) is again heated for a predetermined time (several minutes to several hours) with hot water (about 80 to 180 ° C.), steam, high frequency, etc. before drying. A slightly compressed shape in the dry case (4) may be fixed. In this case, since the shape of the wood (1) is fixed before drying, the wood (1) is further effective in preventing cracking and distortion during drying, and is also effective in preventing warpage and distortion. There is.
[0022]
【The invention's effect】
As described above, according to the present invention, when a wood is dried to a desired dry state, the wood is heated and softened with warm water or steam and the like, and the water contained therein is forcibly squeezed out. By drying in a dry state, the drying time can be greatly shortened to drastically reduce the drying cost, and cracking and distortion during drying can be prevented to reduce defective drying.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a state in which wood is softened by heating in a treatment tank.
FIG. 2 is an explanatory diagram showing a state in which heat-softened wood is housed in a dry case while squeezing moisture.
FIGS. 3A and 3B are detailed views of a drying case for accommodating wood, in which FIG. 3A shows a drying case formed in a mesh shape, and FIG. 3B shows a drying case formed in a porous shape.
FIG. 4 is an explanatory diagram showing a state in which wood stored in a drying case is primarily dried.
FIG. 5 is a diagram of another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wood 2 Processing tank 3 Draft apparatus 4 Drying case 5 Draft tube 5a Carry-in port 5b Carry-out port 6 Push-in cylinder 6a Piston rod 6b Push-in plate 7 Hot plate 8 Compression roller 9 Lattice conveyor

Claims (1)

A draft tube consisting of a compression tube or a lattice conveyor facing up and down, through which a cross-sectional area ratio gradually narrows from the carry-in entrance through which the heat-softened wood passes to the carry-out exit , or the wood passes between ; It is arranged on the carry-out side of the draft device, and has a cross-sectional area that is larger than the cross-sectional area of the wood and slightly smaller than the original cross-sectional area of the wood, and is made mesh-like or porous. and breathable good cylindrical drying case Te, and characterized in that said timber, equipped with a means for supplying during forced push Dari I, or the compression roller or lattice conveyor in the draft tube apparatus for drying wood you.

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