JPH0139882B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a manufacturing method for increasing the moisture content of wood to produce high moisture content wood. Using this method, we can shorten the boiling time for wood that is difficult to slice.
It was developed for the purpose of obtaining advantages such as drying wood that tends to break easily during drying without cracking, and uniform staining of wood that is difficult to inject uniformly.

In the conventional method, the moisture content distribution of the wood is uneven and the wood is partially shrunken, so a long period of 1 to 4 weeks is required for the pre-boiling process to make the sliced veneer. Even when trying to dye, a situation has arisen in which only uneven injection is possible. Recently, there has been an increase in the amount of wood that has been sawn outside, and the water content has partially disappeared from the beginning, and many of the trees tend to crack when heated to dry them. Wood that shrinks and dries with uneven moisture content distribution undergoes various deformations during and after processing. In order to eliminate these drawbacks, it is necessary to first reduce the moisture content in the wood to a material with a high moisture content, and then take measures according to each purpose.

First, an embodiment of this method will be explained based on the attached drawings. A piece of wood 3 is placed in a water tank 1, and a floating prevention device 4 is installed to prevent it from floating even if water is poured into the tank.
Attach water tank 1 to pressure vessel 2 using a trolley etc.
After connecting the steam injection pipe 5, high temperature water inlet 6, cold water inlet 7, and drain port 8 attached to the water tank 1 to the pipe attached to the pressure vessel 2, the door of the pressure vessel 2 is closed and hermetically sealed.

Next, before entering the process of making a high moisture content material, it is easier to make a high moisture content material with even moisture content by performing the following pretreatment.

When using normal wood and free water exists in all the wood, when the valves of the high-temperature water inlet 6 and the cold water inlet 7 are closed and the injection of high-pressure steam is started from the steam injection pipe 5, the water in the water tank 1 Air is forced in and out from the water tank, and the air inside the pressure vessel 2 also sequentially flows out from the drain port 9, so that the water tank 1 and the pressure vessel 2 are filled with saturated steam. As the temperature of the wood 3 in the water tank 1 rises due to steam heating, condensed water accumulates in the water tank 1, but the condensed water is appropriately discharged to the outside from the drain 8 to prevent the wood 3 from being soaked in condensed water. prevent. When the temperature of the thermometer 15 attached to the pressure vessel 2 reaches a predetermined temperature, the steam injection from the steam injection pipe 5 is stopped, and if it continues as it is, the pressure in the water tank 1 and the pressure in the pressure vessel 2 will become the same. However, while the steam injection continues, the pressure in the water tank 1 increases and then the pressure in the pressure vessel 2 increases, so
The steam pressure in the water tank 1 is slightly higher than the steam pressure in the pressure vessel 2. Compound gauge 1 attached to pressure vessel 2
When the pressure at 6 reaches a predetermined pressure, the steam injection from the injection pipe 5 is stopped, and the steam is immediately discharged while controlling the drain ports 8 and 9. When the pressure in the compound gauge 16 falls to a predetermined pressure, the discharge of steam from the drain ports 8 and 9 is stopped, and steam injection from the injection pipe 5 is immediately started. In this way, when the steam injection from the injection pipe 5 and the steam discharge from the drain ports 8 and 9 are automatically repeated according to the instructions from the compound meter 16, the steam pressure fluctuates and Even if the time interval between pressure fluctuations is the same, if the lowest pressure during pressure fluctuations is kept constant, the range of pressure fluctuations will vary only when the pressure in the water tank becomes slightly higher than the pressure in the pressure vessel. Since the width is larger than the guideline of the compound meter, the ratio of the difference in pressure and depressurization under pressurized conditions will be larger than when no water tank is installed, and the high temperature condensation water that is generated on the wood surface will be increased. permeates into the interior of the wood when pressure is applied, and the low-temperature free water that originally exists inside the wood migrates to the surface layer when the pressure is reduced, accelerating the mixing of the water contained in old and new wood. The speed at which the temperature becomes uniform is accelerated. Since the wood is placed in a water tank with a large amount of steam inside the pressure vessel, the wood tends to become relatively soft compared to a case without a water tank. Thereafter, the valve of the injection pipe 5 is closed, steam heating is stopped, saturated steam is released and the pipe is sealed, and the vacuum pump 10 starts operating. When the gas in the pressure vessel 2 is discharged through the condenser to create a reduced pressure state, the water contained in the wood 3 becomes boiling steam and is released. Even if the pressure reduction level of the coupled gauge 16 attached to the pressure vessel 2 becomes larger or the pressure reduction speed becomes faster, since the wood 3 is still in the water tank 1, the residence period of this boiling steam will be limited within the pressure vessel. As it lasts longer, a phenomenon occurs in which the wood is covered with boiling steam of its own water and the water continues to boil, and even a sudden pressure drop seen from the pointer of the coupled meter 16 will not cause cracking or damage to the wood. Although it is rare, the difference between the boiling vapor pressure inside the wood and the pressure inside the pressure vessel becomes large. A phenomenon occurs in which the water is expanded due to the boiling pressure of the water. The resin adhering to the throttle hole is also removed at the same time. When high-temperature water is injected into the wood, the narrow apertures that obstruct injection into the cell cavities and the resin attached to the apertures are removed, making the wood easier to inject, allowing high-temperature water to be injected. A possible place for this to occur is the wood in the whole cell cavity, where about one-third of the water contained in the whole cell cavity emanates from.

Since the above pretreatment process utilizes boiling of free water within the wood, it cannot be used for wood that has been sawn for a long time and has almost no free water, even for normal wood. This type of wood, wood species that crack when exposed to high-temperature steam jets, such as cod wood, wood species with a high specific gravity that is difficult to dry, such as matoa, and wood species that are difficult to dry, such as black tongue, that crack when exposed to high-temperature steam jets. In the case of wood in which free water does not exist, a separate treatment is carried out that takes advantage of the double structure, in which a water tank is placed inside a pressure vessel, especially in the case of equipment using the method of the present invention. However, this will not be described in this application.

After completing the above pre-treatment, stop the vacuum pump, introduce high-pressure steam from the injection pipe 5 or 12 to eliminate the decompression state, and then pour hot water from the high-temperature water inlet 6 to the water tank 1.
The inside of the water tank is filled with hot water, high pressure steam is ejected from the injection pipe 5, and the temperature inside the water tank is raised. Prevents boiling of high temperature water,
When the temperature of the high temperature water in the water tank 1 reaches the boiling point temperature of the saturated steam pressure in the pressure vessel 1, the injection of steam from the injection pipe 5 is stopped, and the injection of steam from the injection pipe 12 is resumed.
When steam is released from the drain port 9 alternately and the saturated steam pressure inside the pressure vessel 2 is frequently fluctuated within a predetermined range, the high-temperature water in the water tank 1 is heated to a high temperature inside the wood due to the width of the fluctuation. Since water penetrates and the cause of the problem of inhalation of the contained water is removed first, the wood becomes a high moisture content material with an equal temperature and moisture content distribution throughout the wood.

As an application example of the method of making high moisture content material of the present invention, it is said that it is impossible to uniformly inject the staining solution to the entire wood when injecting dyeing liquid for most wood products, but the present invention Although it is possible to uniformly inject and uniformly dye the entire lumber product using the apparatus described above, this is not described in this application.

In recent years, the use of thickly peeled veneers has spread to the use of sliced veneers, and as a result, the number of days required for boiling the original veneer has increased, with many products boiling for a short period of one week and many requiring as long as 4 weeks. However, by using the method of the present invention, it has become possible to make thickly sliced veneers without boiling on the first day of processing. After achieving the above-mentioned uniform high temperature and high moisture content, the injection pipes 5 and 12 are closed, and water is injected from the cold water inlet 7 in order to prevent boiling of the high temperature water in the water tank and evaporation of the water contained in the wood. Gradually inject into aquarium 1 and raise the temperature in the aquarium to 100℃.
After the following conditions are met, the saturated steam in the pressure vessel 2 is discharged from the drain port 9, the hot water in the water tank 1 is discharged from the drain port 8, the door of the pressure vessel is opened, the water tank is taken out from the pressure vessel, and the high water content is removed. Take out the aged wood and run it through a slicing machine.

In addition, the number of imported materials that have been sawn outside has increased, and the distribution of water content in these materials is extremely uneven.All drying methods have come to treat all wood using the same method and at the same level. If there is an uneven distribution of water content at the beginning of drying, the wood will continue to dry with uneven moisture content until the end of drying, so defects are likely to appear in the treated wood during drying, and uneven moisture content will remain even after drying is complete. It has been plagued by drawbacks such as distortion in processed wood. In order to reduce these problems as much as possible, there is currently a preventive measure that requires approximately three times the normal drying period, even though the moisture content has decreased and the state is semi-dry. It was happening. In order to solve these problems, it is better to use the method of the present invention to make wood that can easily move the water contained in it, and to make the whole material into a material with a uniform high moisture content. However, the subsequent processing will not be described in this application.

Even with high specific gravity materials such as matoa and black sardines, the process of making high moisture content materials greatly enlarges the capillaries and pores even though the cell wall structure is thick.
It has become easier to inject high-temperature water, eliminating the need for long boiling days to make sliced veneers. Paradoxically, this means that it has become easier to release the water contained in By using the method of the present invention, a path to solving the problem of drying tree species that is difficult to dry has been opened for the first time.

As shown in the above embodiments, the present invention is based on a method of converting wood into high moisture content material. As a result, it has become possible to solve various problems that were impossible with conventional construction methods, which has greatly benefited the industry.

[Brief explanation of drawings]

The figure is a configuration diagram for carrying out the present invention. 1...Water tank, 2...Pressure vessel, 3...Wood, 4
...Floating prevention device, 5, 12... Injection pipe, 6...
High temperature water inlet, 7... Cold water inlet, 8, 9... Drain port, 10... Vacuum pump, 11... Condenser, 13... Air intake/exhaust port, 14... Safety valve, 15
...Thermometer, 16... Compound meter.

Claims (1)

[Claims] 1 The wood in the water tank built into the pressure vessel,
After processing using variable processing using saturated steam and depressurization, the outside of the water tank is filled with saturated steam above atmospheric pressure, and the inside of the water tank is filled with high temperature water corresponding to the boiling point of the saturated steam pressure, and the saturated steam pressure is varied. After turning the wood into a high-moisture content material, cold water is poured into the water tank to lower the temperature of the hot water, and then saturated steam and hot water are released to bring the wood to a boiling point above atmospheric pressure. A method for making wood into a high-moisture content material, which is characterized by making the wood into a high-moisture content material with water and taking out the high-moisture content material from a pressure vessel without boiling the injected high-temperature water.