Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B3/00—Drying solid materials or objects by processes involving the application of heat
  • F26B3/02—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air
  • F26B3/04—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air the gas or vapour circulating over or surrounding the materials or objects to be dried
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B3/00—Drying solid materials or objects by processes involving the application of heat
  • F26B3/18—Drying solid materials or objects by processes involving the application of heat by conduction, i.e. the heat is conveyed from the heat source, e.g. gas flame, to the materials or objects to be dried by direct contact
  • F26B3/20—Drying solid materials or objects by processes involving the application of heat by conduction, i.e. the heat is conveyed from the heat source, e.g. gas flame, to the materials or objects to be dried by direct contact the heat source being a heated surface, e.g. a moving belt or conveyor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B9/00—Machines or apparatus for drying solid materials or objects at rest or with only local agitation; Domestic airing cupboards
  • F26B9/06—Machines or apparatus for drying solid materials or objects at rest or with only local agitation; Domestic airing cupboards in stationary drums or chambers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B2210/00—Drying processes and machines for solid objects characterised by the specific requirements of the drying good
  • F26B2210/16—Wood, e.g. lumber, timber

Definitions

• the present invention relates to a method and an apparatus for drying wood, and more particularly to a technique suitable for high-speed drying of raw wood logs at high temperatures.
• a conventional wood drying method for drying wood in an artificial heating environment is to cut a raw wood into a size larger than a desired product wood size and to saw the lumber, and to expose the sawn wood as it is.
• the so-called “medium temperature drying method” is the mainstream, in which the material is placed in a drying room and dried over a relatively long time of about several weeks under a medium temperature heating environment of about 80 degrees Celsius.
• the reason for heating at a medium temperature of about 80 degrees Celsius is that in a heating environment exceeding about 90 degrees Celsius, the wood to be dried cracks and cannot be used as a product. With such medium-temperature heating, drying took several weeks (for example, two weeks), and high-speed drying could not be performed.
• the reason for drying the lumber in a state where the lumber is larger than the desired product wood size is that the wood always undergoes deformation such as warpage or bending as a result of drying. This is to cut the surrounding area and re-saw the lumber to the desired product wood size (draw twice). Therefore, there is a disadvantage that the yield of product wood is very poor.
• due to such re-milling if the timber diameter of the raw wood is relatively small, it is necessary to apply this ⁇ medium temperature drying method '' to obtain the appropriate size of product wood that can be used. This "medium-temperature drying method" could not be applied because it was impossible. Larch is a typical example of such a relatively small-sized log.
• Larch in particular, had a problem of so-called "abare” in that when dried, large twists, warpage, cracks, etc. occur. Larch has not been able to be artificially dried for a reason, so it has not been possible to distribute larch as industrial lumber and use it widely.
• the present invention has been made in view of the above points, and enables high-speed drying of wood at a high temperature without causing (or minimizing) deformation such as cracking, warping, or bending of the wood to be dried. It is an object of the present invention to provide a method and an apparatus for drying wood that can be used. Another object of the present invention is to provide a method and an apparatus for drying wood, which is suitable for high-speed drying of raw wood logs at high temperatures.
• the method for drying wood according to the present invention is characterized in that wood coated with a material having good heat conductivity and heat resistance is placed in a high-temperature environment not exceeding the ignition point, and the wood is dried. is there.
• the material having good heat conductivity and heat resistance is a metal foil.
• the metal foil is an aluminum foil.
• the wood to be dried is covered with a material having good heat conductivity and heat resistance (preferably, metal foil or aluminum foil). Even if exposed, the wood surface will not be scorched and the like, and the wood surface will be prevented from drying out.
• a material having good heat conductivity and heat resistance preferably metal foil or aluminum foil
• the drying process proceeds in a high-temperature steamed state. It will dry almost evenly, no cracking from the wood surface will occur, and no deformation such as warpage or bending will occur.
• drying can be performed in a considerably high temperature environment, which is not so far at about 200 degrees Celsius, for example, the period required for drying can be considerably reduced.
• FIG. 1 is a schematic diagram for explaining an embodiment of a method and an apparatus for drying wood according to the present invention.
• the first step of the drying method according to the present invention comprises, as shown in FIG. 1 (a), an operation of coating a long piece of wood 1 to be dried with aluminum foil 2.
• This coating work may be performed manually, but may of course be mechanized if necessary.
• the aluminum foil 2 is selected as a material having good heat conductivity and heat resistance, and easily transmits high-temperature heat heated from the outside to the coated wood 1 (good heat conductivity). It cannot burn itself (heat resistance). Therefore, the material (2) covering the wood 1 is not limited to the aluminum foil 2 as long as it is a material having good heat conductivity and heat resistance, but may be other metal foils or any other metal foil. It may be something.
• the vertical length of the wood 1 is considerably long, so that the aluminum foil 2 is spirally wrapped around the wood 1 as shown in the illustrated example. It is sufficient to cover the entire periphery of the wood 1 by winding it in a shape.
• the wood tip la portion of the wood 1 is not covered with the aluminum foil 2, but the entire circumference of the cylindrical side surface of the wood 1 is covered with the aluminum foil 2.
• the present invention is not limited to this, and the entire periphery of the wood 1 including the mouth la may be covered with the aluminum foil 2.
• the thickness of the aluminum foil 2, that is, the thickness of the coating material may be appropriate.
• Wood 1 to be dried (aluminum foil 2, that is, wood covering the covering material) may be a raw log (a log with the raw wood skin peeled off). However, if the log is too large and it is difficult to handle it, the wood that has been cut to an appropriate size can be used as the wood to be dried 1 (aluminum foil 2, that is, the wood that covers the coating material). No problem. If necessary, the log may be split in advance and the periphery of the split log 1 may be covered with aluminum foil 2, that is, a coating material.
• the wood 1 covered with the aluminum foil 2 is carried into a drying kiln (drying device) 3, and the ignition point is determined. It consists of drying the wood by placing it in a high-temperature environment that does not exceed it and exposing it to the high-temperature environment for an appropriate period.
• the drying kiln 3 has, for example, a furnace chamber which is appropriately inclined in an ascending kiln form, has a door 3a for taking in and out of the wood 1 at a lower part of the inclination, a smoke outlet 3b at an upper part of the inclination, and A heating furnace 4 is provided at the bottom near the lower part of the slope.
• an appropriate combustible substance mainly composed of skin (waste skin material) peeled from the surface of the raw wood may be burned.
• the heat source of the heating furnace 4 is not limited to this, and may be any other type such as electric heat.
• high frequency drying means and the like may be appropriately included.
• a plurality of temperature measuring devices 5 are arranged at appropriate places in the drying kiln 3 to monitor the temperature in the kiln. The calorific value of the heating furnace 4 is controlled based on the monitored temperature inside the kiln, and the inside of the drying kiln 3 is maintained at an appropriate high temperature environment not exceeding the ignition point.
• the control of the combustion amount (heat generation amount) of the heating furnace 4 in consideration of the measured temperature may be performed by an automatic method or may be performed manually by an operator. Good.
• manual control or automatic control
• An alarm device that emits a sound or a light-emitting Z display may be added.
• the pressure in the drying furnace 3 may be the same as the outside pressure. However, if necessary, the drying under reduced pressure may be appropriately combined.
• the ignition point temperature of wood is about 237 degrees Celsius. Therefore, in the present invention, the wood 1 can be dried in a high temperature environment of about 200 degrees Celsius, which is a high temperature not exceeding the ignition point. In this case, even if the log is about 30 cm in diameter, it can be dried to a moisture content of about 10% by drying it for about 3 to 4 days using the method of the present invention. Experiments have shown that this can be done. Considering that the conventional artificial drying for several weeks was limited to a water content of about 18%, it can be seen that the efficiency is considerably high. The water squeezed out of the wood 1 during the drying process mainly drips out from the lapel.
• the wood 1 to be dried is covered (wrapped) with a material having good heat conductivity and heat resistance such as the aluminum foil 2, so that the temperature does not exceed the ignition point, but the Near! Even when exposed to a high-temperature environment of about 200 degrees Celsius, the surface of the wood does not scorch or change color, and the quality of the wood 1 is not impaired.
• the coating can prevent a phenomenon that the wood 1 dries from the surface.
• the drying process proceeds in a high-temperature steamed state, and both the surface and the inside of the wood 1 are substantially The wood will dry evenly, and no or almost no cracking will occur on the surface of the wood, and no deformation such as warpage or bending will occur.
• drying can be performed in a considerably high temperature environment, which is not possible in the past, for example, at about 200 degrees Celsius, the time required for drying can be reduced to about 3 to 4 days.
• the logs can be dried as they are, and the necessary lumber treatment can be performed after drying. The yield is very good.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Microbiology (AREA)
• Chemical And Physical Treatments For Wood And The Like (AREA)
• Drying Of Solid Materials (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (7)

Families Citing this family (5)

Citations (3)

Family Cites Families (5)

• 2003
  • 2003-10-08 JP JP2003349421A patent/JP3886952B2/ja not_active Expired - Fee Related
• 2004
  • 2004-10-07 WO PCT/JP2004/014849 patent/WO2005035211A1/ja not_active Ceased
  • 2004-10-07 EP EP04792146A patent/EP1681144A4/en not_active Withdrawn
  • 2004-10-07 CA CA002542000A patent/CA2542000A1/en not_active Abandoned
  • 2004-10-07 CN CNA2004800293295A patent/CN1863652A/zh active Pending
  • 2004-10-07 US US10/574,754 patent/US20070130788A1/en not_active Abandoned
• 2006
  • 2006-04-21 FI FI20060385A patent/FI20060385A7/fi unknown

Patent Citations (3)

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