JP3864083B2 - Apparatus and method for wet heat treatment of wood or wood products - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to wet heat treatment of wood or wood products.
[0002]
[Prior art]
Conventionally, in order to eliminate pests and harmful microorganisms contained in the materials of wood or wood products that cause damage to the material structure and surrounding environment, for example, when used as packing materials for export, due to quarantine problems, etc. It was necessary to disinfect.
[0003]
Such disinfection methods include fumigation treatment with a drug such as methyl bromide, dry temperature for a predetermined temperature at a normal pressure, dry heat for a predetermined time, and wet heat treatment.
[0004]
However, the fumigation treatment with the above-mentioned chemicals has a problem from the viewpoint of environmental conservation. In the treatment with dry heat or wet heat, the center temperature of the wood or the wooden product is raised to 56 ° C. or higher, and this 56 ° C. or higher is increased. Since it is necessary to continue for 30 minutes or more, even if the thickness of the member is about 30 mm, it takes 3 to 6 hours in the stacked state, the member is thick, and the stacked height and width are large. In some cases, it may take several tens of hours, and there is a problem that it takes too much time.
[0005]
In order to solve these problems, a method has been developed in which wood or wood products are cured in high-temperature and high-pressure steam and disinfected without requiring a long time.
[0006]
This method increases the osmotic pressure of steam, which is a heat source, to the inside of the wood by quickly increasing the temperature of the high-temperature steam, and quickly disinfects the inside of the wood. It can be achieved faster than the case. Furthermore, by depressurizing from the pressurized state with high-temperature steam, the wood at the time of pressurization is heated until it reaches a temperature equal to or higher than the boiling point at normal pressure by utilizing the fact that the boiling point drops at the time of depressurization. A method of boiling the moisture inside the wood and evaporating it as water vapor to dry it is also considered.
[0007]
[Problems to be solved by the invention]
By the above method, it was possible to heat and disinfect wood quickly and reliably, and further to dry wood, but when heat curing in the high temperature and high pressure steam, the liquid in the effluent from the woody (It is also referred to as an extract because it contains an active ingredient.) And the resin is mixed with the vapor condensation water and discharged.
[0008]
The extract discharged here contains acetic acid, lignic acid, etc., and is generally close to a liquid called wood vinegar, and its acidity also indicates pH 4 to 3 depending on the state of collection. is there. The resin is the same as that of pine ani, which is generally called, and exhibits fluidity at high temperatures, but is semisolid at room temperature and has a high viscosity.
[0009]
When heating wood or wood products by the above method, examples of the heating container include concrete secondary products and autoclaves used for curing cement-based boards. Since these autoclaves are cured with alkaline products, the inner surface is not acid-resistant, and the inner surface of the autoclave may corrode due to adhesion of the extract in the discharged matter to the inner surface of the autoclave.
[0010]
When overheating curing is performed with high-temperature and high-pressure steam using the autoclave or the like, condensed water, that is, surplus water is generated in the heating container, and therefore an openable / closable discharge valve is provided for draining the surplus water. However, when the resin contained in the discharged product falls and flows into the discharge valve, the outside of the discharge valve is at room temperature, so that it hardens at the position of the discharge valve and may hinder the function as the valve.
[0011]
Moreover, the extract and resin which are the discharge | emission discharged | emitted at the time of a heating will harm a can and its peripheral device by making it flow as it is at the time of a heating. However, an extract that shows acidity as its component is similar to a charcoal vinegar that is extracted when dry distillation of wood to produce charcoal and is used in preservatives, cosmetics, and the like. As for the resin, for example, pine sprout of resin from Akamatsu, Yonematsu, etc. can purify turpentine oil used as a solvent from this pine sprout, and can be fully utilized depending on its components.
[0012]
The present invention has been made in view of these problems. When wood or wood products are subjected to wet heat treatment, the waste discharged from the wood is discharged outside without touching the inside of the moist heat container, and the discharged matter. The secondary use of
[0013]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention has a surplus water discharge valve that discharges surplus water condensed with steam, and a mixed liquid discharge valve that discharges a mixed liquid extracted from wood and surplus water. The surplus water generated by condensation of the steam in the autoclave when the wood and the stage on which the wood is mounted is carried into the autoclave that is treated with the high-temperature and high-pressure steam, and the steam is condensed in the autoclave. The moisture of the wood or wood products discharged from the autoclave to the outside of the autoclave so that the extract and steam discharged from the wood inside the autoclave are not condensed inside the autoclave and contact with the inside of the autoclave. A heat treatment method was used.
[0014]
As a device for performing the treatment by the above method, a mixed liquid containing an extract that is held from inside and has an openable and closable surplus water discharge valve that retains high-temperature and high-pressure steam therein and discharges surplus water condensed by the steam. In a wet heat treatment apparatus comprising an autoclave having a mixed liquid discharge valve for discharging the gas and a table on which wood or wooden products that can be carried into the autoclave is placed, the table includes exhausts and wood discharged from the wood or wooden products It has a receiving plate that catches excess dripping water and is inclined in the direction of one side or both sides or the center of the table. Inside the autoclave below the lower end in the inclination direction of the receiving plate, a plurality of the tables are carried into the autoclave. And a heat sink that corresponds to the receiving plate of each table and discharges the mixed solution from the receiving plate to the mixed solution discharge valve. Using the physical device.
[0015]
In the autoclave, a receiving plate is provided on a table for carrying wood or a wooden product, and the receiving plate receives waste discharged from the wood and surplus water dripping from the wood. The receiving plate is inclined toward one side, both sides, or the central direction, and the autoclave located below the lower end in the inclined direction of the receiving plate is provided with a plate corresponding to a table provided with the receiving plate. Is installed. This is a device that receives the discharge from the receiving plate and flows it to the mixed solution discharge valve, and discharges the mixed solution from the autoclave through this discharge valve.
[0016]
Examples of the wet heat treatment apparatus include those used for concrete secondary products, cement-based boards, etc., but are not limited thereto. In short, curing with high-temperature and high-pressure steam is possible, and wood or wood products are contained inside. If it can be brought in, it will not be particular about the type.
[0017]
The receiving plate receives waste discharged from the wood or the wooden product on the upper surface thereof, and has a filter at a lower end portion in the inclination direction of the upper surface of the receiving plate.
[0018]
In addition, the bag has a discharge hole for discharging the discharged substance from a receiving plate provided at the upper side, and has a discharge hole for discharging the discharged substance, and the periphery of the discharge hole is covered with a filter.
[0019]
The waste discharged from the wood or wood product is composed of a liquid extract and a solid resin component. This solid resin component has a certain degree of fluidity in a wet heat state, but when cooled to the outside of the autoclave through a discharge valve or the like, it is cooled and becomes a highly viscous semi-solid. Therefore, in order to prevent the resin component having high viscosity from being discharged from the mixed liquid discharge valve and clogging the mixed liquid discharge valve, a filter that captures this resin component is provided on the receiving plate and the trough, and is provided in the mixed liquid discharge valve. Do not reach.
[0020]
A discharge hole provided in the basket is provided above the mixed solution discharge valve, and a storage tank is provided between the discharge hole and the mixed solution discharge valve so that the inner surface of the autoclave is not in contact with the liquid in the discharge.
[0021]
The liquid mixture discharge valve is not always open, but is opened based on predetermined conditions such as time, internal pressure change, temperature change, etc. A place to store to some extent when flowing to the valve is required. While the liquid generally has a pH of 4 or less, the autoclave does not have acid resistance, so the liquid cannot be directly in contact with the inner surface of the autoclave. Therefore, the storage tank which stores an extract liquid without contacting an autoclave inner surface is provided.
[0022]
Moreover, since the liquid in the discharged material is always discharged from the discharge valve by using the receiving plate and the basket, it is not necessary to provide a device for storing the discharged material inside the autoclave. Can be increased.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment)
Hereinafter, a wet heat treatment apparatus for wood or wood products according to the present invention will be described with reference to the drawings.
FIG. 1 shows a conceptual diagram of an embodiment of the present invention.
[0024]
The autoclave 4 used in the present embodiment has a cylindrical shape for curing concrete piles, cement boards, etc., which are secondary concrete products, and is cured using an autoclave device that can be filled with high-temperature and high-pressure steam. Device. The autoclave 4 used in such an autoclave apparatus is suitable for the purpose of the present invention because it has a large capacity and the inside atmosphere is kept uniform.
[0025]
The autoclave 4 has doors 8 serving as doorways at one end or both ends in the longitudinal direction, and is opened and closed by a hydraulic device (not shown). An object to be cured is carried into the autoclave 4 from the door 8 using the carriage 3.
[0026]
The autoclave 4 includes a pressure sensor 11 and temperature sensors 12 a and 12 b that detect pressure and temperature, and detection signals from these sensors are transmitted to the control device 10. The control device 10 controls the intake and exhaust devices 13 including a vacuum pump and intake and exhaust valves and a high-pressure steam injection device 14 connected to a boiler (not shown) to adjust the temperature and pressure inside the autoclave 4. Along with the above control, the control device 10 controls the mixed liquid discharge valve 7a for discharging the mixed liquid in the autoclave 4 and the driving devices 15a, b for driving the surplus water discharge valve 7b, and the accumulated liquid mixture and surplus water are stored in a predetermined amount. Discharge to the outside of the autoclave 4 at certain times.
[0027]
The pressure sensor 11 is generally known to those skilled in the art, such as a pressure gauge, and examples of the temperature sensors 12a and 12b include thermocouples. A plurality of temperature sensors 12a and 12b are provided at various locations so that the temperature inside the autoclave 4 can be grasped, and also provided at the center member of the wood 1 to measure the wood center temperature.
[0028]
The body of the autoclave 4 is made of steel so that it can withstand high pressures, and the nourishment that is carried into the inside is generally a cement-based or other alkaline product. . Since the size of the autoclave 4 is, for example, a utility pole as a concrete secondary product or a cement-based board, the diameter is usually 2.5 to 4 m and the length is 20 to 60 m. And is suitable for the wet heat treatment of the present invention in terms of capacity.
[0029]
The wood 1 as a processed material is carried into the autoclave 4. This wood 1 is a wood used for packing materials for export, and a plurality of 15 cm wide plates stacked in a thickness of about 40 cm and bound together as one unit. It is piled up to have. The wood 1 is installed on the receiving plate 2 so that the end of the wood 1 is located inside the receiving plate 2, and the receiving plate 2 can receive the discharge discharged from the wood 1. This backing plate 2 is installed on a carriage 3.
[0030]
The discharged matter received by the receiving plate 2 is composed of an extraction liquid composed of moisture in wood as a liquid, a product obtained by decomposing wood by heat, and a resin in wood as a solid. This extract has the same component as the pyroligneous acid produced when the wood is carbonized, and exhibits a pH of 4 to 3. Further, the resin is the same as the pine crab leached from wood such as red pine and rice pine.
[0031]
As shown in FIG. 2, the receiving plate 2 is attached to a position connecting the upper side of one side of the frame 2b and the lower side of the other side inside a frame 2b made of square material or the like. An inclined frame is formed by installing the frame 2 b including the carriage 2 on the carriage 3. Therefore, the extraction liquid, which is a liquid discharged on the receiving plate 2 that forms the slope, is discharged from the lower end direction of the receiving plate 2 to the bowl 5.
[0032]
Further, by making the inclination of the inclined surface of the receiving plate 2 gentle, and providing the filter 2a at the lower end in the inclined direction, it becomes possible to hold the resin in the discharged material on the receiving plate 2. Further, below the lower end of the receiving plate 2, a gutter 5 provided inside the autoclave 4 for receiving the extracted liquid discharged from the receiving plate 2 is installed.
[0033]
As described above, the basket 5 is provided in the autoclave 4 in parallel with the carriage 3. The discharge hole 5 b is formed above the mixed solution discharge valve 7 a provided in the autoclave 4. The liquid is discharged out of the autoclave 4 from the hole 5b using the mixed liquid discharge valve 7a. A filter 5a is provided around the discharge hole 5b for discharging the liquid so that the resin component does not flow out to the mixed liquid discharge valve 7a in the same manner as the filter 2a provided on the receiving plate 2. Moreover, this cage | basket 5 is provided in series from the door 8 position of the autoclave 4 to the innermost part. As a result, regardless of the number of the carriages 3, all the carriages 3 carried into the autoclave 4 can collect and discharge the discharge. It should be noted that the discharge hole 5b may be at the lowest position in the flange 5 and a slope may be provided toward both ends thereof to facilitate the flow of the extract.
[0034]
A storage tank 6 is provided between the basket 5 and the mixed solution discharge valve 7a. The storage tank 6 prevents the extraction liquid discharged from the receiving plate 2 and the trough 5 from being mixed with surplus water generated inside the autoclave 4 and also exhibits acidity on the inner surface of the autoclave 4 that has not been acid-resistant. It is for preventing that it adheres and corrodes. Therefore, the mixed solution discharge valve 7a in which the storage tank 6 is installed serves as a discharge valve dedicated to the extract, and a tank 9 is installed at the outlet to collect the discharged extract.
[0035]
Since the mixed solution discharge valve 7a needs to discharge the extract according to the situation, the drive device 15a is used so that the valve can be opened and closed arbitrarily. On the other hand, the surplus water discharge valve 7b that discharges surplus water in the can can be opened and closed using the driving device 15b, and only when surplus water is generated due to a decrease in the can water temperature and a decrease in saturated water vapor amount. Two bimetal devices that open the valve are used together.
[0036]
The wood 1 is sterilized and dried using the wet heat treatment apparatus configured as described above. The processing steps will be described below with reference to FIG.
[0037]
When the wood 1 is sterilized and sterilized, it is necessary that at least the central temperature 32 of the wood 1 is maintained at 56 ° C. or more for 30 minutes or more regardless of the internal temperature 31 of the autoclave 4. In addition, when the wood 1 is dried, it is necessary to boil and evaporate water contained in the wood 1 when the pressure is reduced to at least normal pressure. Therefore, the internal temperature 31 of the autoclave 4 is set to 130 ° C., and the wood 1 is heated to heat the center temperature 32 to a predetermined temperature of 56 ° C. or higher.
[0038]
In the wood 1 (150 mm × 400 mm) of the present embodiment, the time for which the center temperature 32 reaches 56 ° C. and is held for 30 minutes or more is approximately 231 minutes after the internal temperature 31 of the autoclave reaches 130 ° C. It is. The relationship between the internal temperature 31 of the autoclave 4 and the wood 1 center temperature 32, the internal pressure 33 of the autoclave 4 and the time at this time is as shown in FIG.
In the graph of FIG. 3, after the wet heat treatment is started, after the wet heat treatment is finished, until the internal pressure 33 is lowered and the room temperature is reached, the amount of the discharged matter from the wood is the liquid extract. The volume ratio of the wood 1 is about 10%, and the solid resin is about 1%.
[0039]
The extract discharged from the wood 1 in a large amount is discharged outside the autoclave 4. Since this discharged extract has the same components as the acidic liquid discharged when the wood, generally called wood vinegar, is distilled, this extract also uses the same method as wood vinegar, such as cosmetics and pharmaceuticals. Etc. Moreover, since the component of this extract changes depending on the wet heat press condition of the wood 1, it is separated and discharged in each situation. Hereinafter, a method of separating and collecting will be described with reference to FIG.
[0040]
First, it discharges at the time of t ₁ at least during the temperature raising process from the start of wet heat (t ₀ ) to the time (t ₁ ) when the internal temperature 31 of the autoclave 4 reaches 130 ° C. In addition, in order to reduce the capacity of the storage tank 6, it may be discharged once or more before this.
In this temperature raising step, a large amount of dew condensation water is generated on the surface of the wood as the temperature of the surface of the wood rises.
[0041]
Then, from the time when the internal temperature 31 of the autoclave 4 becomes 130 ℃ (t _1), reducing the temperature of the internal temperature 31 holds 231 minutes, the temperature holding step in to when to begin decompression (t ₃₎ At least at time t ₃ . In addition, in order to reduce the capacity of the storage tank 6, it may be discharged once or more before this.
In this temperature holding step, the temperature of the wood surface has finished rising in the previous temperature raising step, so the condensed water on the wood surface is reduced, mainly due to the temperature rise inside the wood, due to the expansion of moisture in the wood, A large amount of interstitial water in the wood is discharged outside the wood, and the amount of the extracted liquid is also increased. Also, during this period, the temperature of the inside of the wood is rising, so that the thermal decomposition of the wood gradually progresses, and substances that become components of the pyroligneous acid liquid produced by this thermal decomposition are also gradually formed. Therefore, the extracted liquid is about pH = 3-4, and is close to the component as a wood vinegar liquid.
[0042]
Next, it discharges at least once during the pressure reducing process until the time (t ₄ ) when the pressure reduction ends and the internal pressure 33 decreases to the normal pressure (0.1 MPa) after the time of starting the pressure reduction (t ₃ ).
In this decompression step, the wood 1 is not heated from the outside, so that it reacts only with residual heat, and new thermal decomposition does not proceed inside the wood. A difference is generated, and the extract contained in the wood in a high pressure state is discharged to the outside due to the pressure difference. The extract discharged during this period has a pH of about 3 to 4, and the acidity itself is almost the same as the extract discharged at t ₃ , but the process discharged from the wood 1 is different. The components are slightly different from each other, and therefore, they are discharged separately from the time before t ₃ .
[0043]
By the method of discharging the extract according to the above case classification, it is possible to prevent extraction solutions having different components from being mixed in each step and extract only effective components.
[0044]
Further, upon discharging the extraction fluid at a time (t ₄₎ is forcibly discharged using a gas supply and exhaust means 13 steam in the autoclave 4 simultaneously.
As a result, the amount of water vapor inside the wood 1 can be reduced as the pressure is reduced, and the moisture contained in the wood 1 can be easily moved to the outside of the wood so that it can be efficiently dried. In addition, the time for discharging the steam is preferably when at least the surface of the wood is at a temperature equal to or higher than the boiling point. If it is in this state, the water | moisture content inside a timber will evaporate easily and it will be in the state which the drying of the timber 1 progresses easily.
[0045]
From the above, the extract discharging device in the present embodiment requires some modification to the autoclave. However, the device added by this modification is added to a place other than the carry-in location occupied by the processed product carried into the autoclave. Therefore, the processing capacity of the autoclave is not substantially reduced by attaching this apparatus. In addition, by using this discharge device, there is no need for workers to enter the autoclave after carrying processed materials such as wood into the autoclave, so that workability is improved and work safety is improved. Can also be secured.
[0046]
In addition, by using this embodiment, even when processing long wood that cannot be accommodated in a single carriage, for example, it is only necessary to cover the connecting portion of the carriage with a plate or the like so that the receiving plate is continuous. This is particularly effective when processing long wood such as pillars and purlins because of wet heat treatment.
[0047]
In this embodiment, for example, as shown in FIG. 4, two drainage channels 40, 41 are installed at one place by providing a drainage channel 41 composed of a small-diameter inner pipe in the drainage channel 40 of one discharge valve. In addition, the mixed solution discharge valve 7a and the excess water discharge valve 7b may be provided at the ends of the drainage channels 40 and 41, respectively, to discharge the extract and the excess water.
[0048]
If it does in this way, the liquid mixture discharge valve 7a can be increased, without reducing the surplus water discharge valve 7b.
[0049]
【The invention's effect】
According to the present invention, it is possible to prevent the autoclave, which is an apparatus for performing the heat treatment, from being corroded by the acidic extract discharged when the wood is subjected to the heat treatment.
[0050]
In addition, by providing a device for discharging the liquid in the discharged material in advance in the autoclave, the processed material can be transferred to the inside of the autoclave only by carrying the processed material into the autoclave. Therefore, it is possible to easily increase the number of processing units, improve workability, and ensure safety. When installing the basket in the autoclave, it is possible to process a long member by installing from the entrance to the innermost part.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram according to the present embodiment.
FIG. 2 is a cross-sectional view of a receiving plate according to the same embodiment.
FIG. 3 is a graph showing a relationship between heating time and temperature according to the embodiment.
FIG. 4 is a sectional view of another form of the discharge valve according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wood 2 Receiving plate 2a Filter 2b Frame 3 Carriage 4 Autoclave 5 Trap 5a Filter 5b Discharge hole 6 Reservoir 7a Mixed liquid discharge valve 7b Excess water discharge valve 8 Door 9 Tank 10 Controller 11 Pressure sensor 12a, b Temperature sensor 13 Absorption Exhaust device 14 High-pressure steam injection device 15a, b Drive device 31 Internal temperature 32 Center temperature 32 Center temperature 33 Internal pressure 40 Drain channel 41 Drain channel

Claims (6)

Inside the autoclave, which has a surplus water discharge valve that discharges surplus water condensed by steam and a mixed liquid discharge valve that discharges the mixture of extract liquid and surplus water discharged from the wood, and processes with high-temperature high-pressure steam Excess water generated by condensation of the steam in the autoclave when the wood and the stage on which the wood is mounted is carried in and treated with high-temperature and high-pressure steam is discharged to the outside of the autoclave through the surplus water discharge valve and discharged from the interior of the wood. A wet heat treatment method for wood or wood products, in which excess water generated by condensation of the extracted liquid and steam from the wood is discharged outside the autoclave from the mixed solution discharge valve so as not to contact the inside of the autoclave. An autoclave having a high temperature and high pressure steam inside, an openable / closable surplus water discharge valve for discharging surplus water condensed by the steam, and a mixed liquid discharge valve for discharging a mixed liquid containing an extract discharged from wood When,
In a wet heat treatment apparatus consisting of a table on which wood or wood products that can be carried into the autoclave is loaded,
The stand has a receiving plate that receives waste discharged from wood or wood products and surplus water dripping from the wood and is inclined in the direction of one side or both sides or the center of the table,
In the autoclave below the lower end in the inclination direction of the receiving plate, when a plurality of the tables are carried into the autoclave, the corresponding plate corresponds to the receiving plate of each table and the mixed solution from the receiving plate is discharged to the mixed solution discharge valve. A wet heat treatment apparatus having a ridge. 3. The wet heat treatment apparatus according to claim 2, wherein the receiving plate receives waste discharged from wood or a wooden product on an upper surface thereof, and has a filter at a lower end portion in an inclination direction of the upper surface of the receiving plate. The said ridge receives the discharge | emission discharged | emitted from the receiving plate which has upwards, and has a discharge hole which discharges this discharge | emission, The circumference | surroundings of this discharge hole are covered with the filter, It is characterized by the above-mentioned. The wet heat treatment apparatus according to 2 or 3 The discharge hole in the tub is provided above the mixed solution discharge valve, and a storage tank is provided between the discharge hole and the mixed solution discharge valve so that the inner surface of the autoclave and the liquid in the discharge are not in contact with each other. The wet heat treatment apparatus according to any one of claims 2 to 4. When wood or wood products are loaded on a table with a receiving plate inclined in one direction, both sides, or in the center direction, the whole table is loaded into the autoclave and filled with high-temperature and high-pressure steam. The waste discharged from the receiving plate is received by a receiving plate, the liquid in the discharged material is collected in a bowl provided below the lower end in the inclination direction of the receiving plate, and the liquid mixture discharge valve provided in the autoclave from the discharge hole drilled in the bowl. A wet heat treatment method for wood or wood products discharged outside the autoclave.

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