JP3485447B2 - Wood drying method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pillar, a base, a spring,
The present invention relates to a method for drying wood used for building structural materials such as digits.

[0002]

2. Description of the Related Art Conventionally, it is necessary to use wood that has been used as a building structural material after it has been sufficiently dried after cutting, but in order to shorten the drying period, it is usually forcedly dried using a dryer. It takes about 600-700 hours (25
It takes about 30 days), and it takes a huge amount of money if the depreciation cost of the drying facility and other drying costs are combined.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The present inventor has studied the shortening of drying days of wood by using a dryer, and as a result, in the conventional dryer, hot air of 80 to 150 ° C. and wind speed of 1.5 to 3 m /
Since it is sprayed on the wood in sec, the side surface and both end surfaces (hereinafter referred to as small edges) of the wood are rapidly dried, and the water content of those surface layers is reduced. Therefore, the decrease in the water content deteriorates the heat conduction to the inside of the wood, and as a result, it takes time to dry the inside of the wood because the surface of the wood is hardened with moisture remaining inside. In the drying of wood, it was found that moisture easily moved along the grain of wood, and the divergence of water from the fore edge was larger than that on the side of the wood. It was clarified that the internal drying time can be greatly shortened by reducing the difference in thermal conductivity between the inside and the inside. Therefore, an object of the present invention is to provide an efficient method for drying wood, which can sufficiently dry the core part in a short period of time.

[0004]

In the method for drying wood according to the present invention, both ends of the wood are covered with a tubular body, and hot air of 80 to 150 ° C. is blown from the outlet of a duct provided in the upper part of the drying chamber to the wind speed.
Wood is spray-dried at 0.1-1 m / sec. wood
It is preferable that the cylindrical body covering both end portions of is made of a material that is water-absorbing and has a low thermal conductivity. The drying device is provided with a duct having a plurality of fans and outlets inside thereof in the upper part of the drying chamber, and these fans are alternately arranged in opposite directions,
It is preferable that a heating source is provided in the vicinity of the air outlet and a control means for adjusting the temperature and the wind speed of the hot air is provided.

In the method for drying wood according to the present invention, the wind speed is
With 0.1 to 1 m / sec of hot air and both ends covered with cylinders
By putting the material, the wood edge is directly exposed to the hot air.Exposed
, It stays moist during drying, and it dries quickly from the edge.
Surface hardening due to drying can be delayed. as a result,
The heat conduction to the inside of the wood is improved, and
The water in the core of the crab can be released through a small edge.
The drying time can be shortened and wood can be dried more evenly.
Wear.

The cylindrical body is formed in a square shape, a round shape or the like according to the cross-sectional shape of the wood so that the small edge of the wood can be covered. In addition, it is necessary to make a gap between the timber and the cylinder, and this gap depends on the size of the timber to be applied, but for example, in the case of a square timber with an end surface of 110 × 110 mm, it is 1
It is good to set it to ~ 10 mm, preferably 2 to 6 mm. Also,
The length of the cylinder is 150 to 250 mm, preferably around 200 mm, the cylinder covers the wood about 50 to 100 mm from its end, and the edge of the wood is about 100 to 100 mm from the open end of the cylinder. It is better to place it so that it is 150 mm deep. Further, the tubular body is preferably made of a material that absorbs water and has a low thermal conductivity, and wood such as cedar is particularly preferable.

The drying method of the present invention for covering the edge of both ends of the wood placed in the drying chamber is based on the established theory that hot air of 80 to 150 ° C. is applied to the wood at a wind speed of 1.5 to 3 m / sec in the dryer. Although it is also effective in the conventional method based on, hot air in the above range, the wind speed 0.1 ~ 1 m / sec, preferably 0.3 ~ 0.5 m / sec
Then, a further effect can be obtained by drying the wood placed in the drying chamber.

That is, when hot air with a wind speed of 1 m / sec or less is blown between the wood placed in the drying chamber, the wood moves gently from the core of the wood to the surface at a speed of about 10 mm per hour. To radiate water. For this reason, surface hardening due to rapid drying of the wood is prevented, and a high-quality and soft-dried wood that does not damage the wood and has no cracks or twists can be obtained.

As a drying device used in the above-described drying method of the present invention, for example, a duct is provided on the top surface of the drying chamber, a plurality of propeller fans are installed in the duct, and the propeller fans are arranged alternately in opposite directions. In addition to maintaining the wind speed in the duct at 20 to 30 m / sec, the air blown from the outlet with a diameter of 30 to 40 mm provided on the outer wall of the duct is heated as a hot air by the heater provided near the outlet. It is advisable to have a structure in which the air is blown out along with and is circulated in the drying chamber. Further, in the drying method of the present invention, the applicant of the present invention, as in the invention previously filed (Japanese Patent Application No. 09-176839), was subjected to dehydration treatment in advance by compressing all sides of the timber as a material to be dried. By using the square wood, the drying time can be further shortened.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The wood drying method and wood drying apparatus of the present invention will be described in detail below with reference to the accompanying drawings.
FIG. 1 (a) is a perspective view showing an example of a tubular body used in the method for drying wood according to the present invention, and FIG. 1 (b) is a perspective view showing a state in which the tubular body is covered on both ends of the timber. It is a figure. FIG. 2 is a schematic plan view showing an example of the wood drying apparatus of the present invention,
3 is a side view thereof, and FIG. 4 is a front view thereof. In addition, FIG.
It is a perspective view showing the state where wood was piled up on the truck which is carried in into the drying device of the present invention.

In the method for drying wood according to the present invention, hot air of 80 to 150 ° C. is blown out from the outlet of a duct provided in the upper part of the drying chamber, and hot air of 0.1 to 1 m / sec is placed in the drying chamber. The burned wood is dried. The cylinder 1 used in this drying method has a cross-sectional shape of the wood to be dried,
When used for a square bar, as shown in FIG. 1 (a), it is formed in a tubular shape having a quadrangular cross section.

When drying, as shown in FIG. 1 (b), both ends of the wooden piece 2 are covered with the cylindrical body 1 so that the small edge 3 is not exposed from the cylindrical body 1. mm inserted and placed in the drying chamber. An example of a drying apparatus that embodies the drying method of the present invention is shown in FIGS. As shown in FIG. 2, this drying device comprises a wood drying chamber 4 and a control chamber 5 for supplying / exhausting air to / from the drying chamber 4.

As shown in FIG. 3, the drying chamber 4 is provided with a duct 6 on the ceiling, and in the center of the inside of the duct 6,
A plurality of propeller fans 7 are provided on the left and right side walls 8, 9 of the duct 6.
Are alternately arranged in the opposite direction. Further, outlets (not shown) having a diameter of 35 mm are provided at predetermined intervals on the side walls 8 and 9 of the duct 6, and a heater 10 as a heating source is provided near the outlet on the outer wall of the duct 6. ing.

The inside of the duct 6 is maintained at a wind speed of 20 to 30 m / sec, and the inside of the drying chamber 4 is kept at a speed of 0.1 to 1 m / sec or less due to the amount of air blown from the outlets provided on the duct side walls 8 and 9. It is adjusted to maintain the desired wind speed. The air blown from the outlet becomes hot air by the heater 10 provided in the vicinity of the outlet of the duct, and the wind speed is zero on the wood in the drying chamber.
Sprayed at 1 to 1 m / sec.

A rail 11 is laid on the floor surface of the drying chamber 4, and a truck 12 on which timber is piled can be moved on the rail 11 as it is and carried into and out of the drying chamber 4. . Ventilation in the drying chamber 4 is performed by the air supply pipe 13 and the exhaust pipe 14 leading to the drying chamber, and the temperature and humidity in the drying chamber are controlled by the control panel 15, and the state at the time of setting is always maintained. As shown in FIG. 5, the wood is dried by stacking the wood 2 with the tubular body 1 on both ends thereof on the carriage 12, and
2 is loaded into the drying chamber 4, the drying chamber 4 is sealed, and then dried by the above procedure.

[0016]

[Example] Size 110 x 110 x 3600 mm, average water content 130
% Of cored lumber was dehydrated to an average water content of 100% in advance, and the square of the timber was covered with a cylinder so that a gap of 3 mm was formed between the timber and the timber.
When hot air of m / sec was blown onto the timber for drying, the water content could be dried up to 18% without cracking or twisting in 60 hours even if the time required for heating and cooling was added.

[0017]

According to the method of drying wood of the present invention, the drying of the wood from the edge becomes slow, the difference in the thermal conductivity between the surface layer part and the inside of the wood becomes small, and the core part of the wood is shortened in a short period of time. Can be fully dried. Further, by compressing the upper and lower surfaces and both side surfaces of the timber and drying the wood that has been dehydrated in advance by the method of the present invention, the effect of further shortening the drying time can be exhibited. In other words, according to the conventional method for drying wood using a dryer, it is difficult to dry the core timber of coniferous wood with a water content of 100% to a water content of 18%.
It took 00 hours (25-30 days), but only 40-70 hours (2-
It takes 3 days) and can be dried sufficiently in a very short time without cracking or twisting.

[Brief description of drawings]

FIG. 1A is a perspective view showing an example of a cylinder used in a method for drying wood according to the present invention, and FIG. 1B is a perspective view showing a state in which the cylinder is covered on both ends of wood. Is.

FIG. 2 is a schematic plan view showing an example of a drying device used in the drying method of the present invention.

FIG. 3 is a schematic side view showing an example of a drying device used in the drying method of the present invention.

FIG. 4 is a schematic front view showing an example of a drying device used in the drying method of the present invention.

FIG. 5 is a perspective view showing a state in which timbers are piled up on a carriage that is carried into a drying chamber.

[Explanation of symbols]

1 cylinder 2 wood 3 small pieces of wood 4 drying room 5 control room 6 ducts 7 Propeller fan 8,9 Side wall of duct 10 heater 11 rails 12 carts 13 Air supply pipe 14 Exhaust pipe 15 control panel

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F26B 9/06 F26B 3/04

Claims (3)

(57) [Claims] 1. An end surface of both ends of wood is covered with a tubular body, and the temperature is 80 to 150 ° C. from the outlet of a duct provided at the upper part of the drying chamber.
The method for drying wood, characterized in that the hot air is blown onto the wood at a wind speed of 0.1-1 m / sec to dry the wood. 2. The method for drying wood according to claim 1, wherein the duct has a plurality of fans and outlets therein, and the fans are arranged alternately in opposite directions. 3. The method for drying wood according to claim 1, wherein the tubular body is made of a material that is water-absorbing and has a low thermal conductivity.