JPH0396302A - Method and device for impregnating liquid into lumber - Google Patents

Abstract

PURPOSE:To obtain a favorable liquid impregnation effect, by a method wherein after completion of decompression, the inside of a tank is pressurized by loading a liquid into the tank with a pressure pump, the liquid in the tank is released under atmospheric pressure and the liquid is impregnated into lumber to be treated while discharging outside residual air existing within the liquid in the tank or on the surface of the lumber to be treated. CONSTITUTION:A decompression nozzle 10 at the upper part of a pressure vessel 1 is closed and a compressed treatment liquid 20 is sent into the pressure vessel 1 with a pressurizing nozzle 11 at the upper side of the pressure vessel 1. Then, along with pressurization of the inside of the pressure vessel 1 a valve 7 is either opened a little with hand-worked operation or opened by actuating the same intermittently by making use of a solenoid valve. With this construction, the inside of the pressure vessel 1 is released under atmospheric pressure and air existing in a liquid in the vessel 1 or on the surface of lumber 2 to be treated is discharged outside of the pressure vessel 1. Then, when a truck 3 is pulled out by opening a lid 9 after restoration of pressure of the inside of the pressure vessel 1 to normal pressure by suspending operation of each device, the lumber to which liquid impregnation treatment is performed can be taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for injecting a treatment liquid such as resin into wood. [Prior Art] Various injection methods and devices of this type have been known in the past. Various treatment liquids are injected into wood to make it flame retardant, stabilize its dimensions, improve its strength, and provide corrosion protection. The product's value is increased by improving its properties and insect repellency, and by dyeing it to expand its uses. In these conventional methods and devices, the wood to be treated is stored in an empty tank in advance, and the air inside the tank is first vacuum-sucked to reduce the pressure inside the tank. After the depressurization process in the tank is completed, process liquid such as resin liquid is poured into the tank while maintaining the depressurized state. Finally, the tank is pressurized so that the treatment liquid is injected into the wood being treated. [Problem to be Solved by the Invention] By the way, in the conventional method, the reason why the treatment liquid is put into the tank after the wood to be treated is treated under reduced pressure is that the treatment liquid is put in the tank from the beginning. However, the air in the wood is difficult to escape (due to the long processing time, and depending on the treatment liquid, it may adhere to the wood surface such as the butt end of the treated wood during depressurization, blocking some of the openings necessary for the liquid to enter). This is because it may not be possible to obtain a uniform injection state of the processing liquid. However, this method requires more work steps compared to placing the wood and treatment solution in the tank from the beginning, since the treatment solution is added while maintaining the reduced pressure inside the tank. Of course, additional control devices and valves were required, and improvements were desired. [Means for Solving the Problems] The method of injecting liquid into wood according to the present invention is a method of injecting liquid such as resin liquid into wood in a tank whose interior can be depressurized and pressurized, and includes the following method. Consists of steps. In the first step, the treated wood to be injected is placed on a truck, the truck is placed in the tank, and the tank is then filled with the liquid. In the second step, the air in the tank is vacuum-sucked to reduce the pressure in the tank, and the air present in the wood to be treated is discharged together with the air in the tank to the outside of the wood. In the third and final step, after the decompression is completed, the liquid is put into the tank using a pressure pump to pressurize the tank, and the liquid in the tank is released to atmospheric pressure via a valve. , the liquid is injected into the wood to be treated while exhausting residual air present in the liquid in the tank or on the surface of the wood to be treated to the outside of the tank. In addition, instead of the step of releasing the liquid in the tank to atmospheric pressure via a valve, a vacuum suction line from inside the tank is provided separately from the vacuum suction line, and a vacuum suction line that is the same as or similar to the wood to be treated is provided along the way. The process may also include the step of interposing a monitor wood having a specific property, vacuuming the inside of the tank, and discharging air present in the liquid or on the surface of the treated wood to the outside of the tank. ．． The device for injecting liquid into wood according to the present invention mainly includes a tank whose interior can be freely depressurized and pressurized, a trolley for loading and storing the treated wood to be injected with the liquid, and the tank. Vacuum suction means for reducing the pressure inside the tank by vacuum suctioning the air inside the tank, discharging the air inside the tank to the outside of the tank, and discharging the air existing in the wood to be treated to the outside of the wood, the tank; The tank is equipped with a valve that opens the liquid inside the tank to atmospheric pressure and discharges air bubbles present in the liquid or attached to the surface of the wood to be treated to the outside of the tank. In addition, instead of the valve, a monitoring device is interposed in the middle of the vacuum suction line that sucks the inside of the tank, and the monitoring device is integrated with a filter section connected to the decompression line and below the filter section. and a monitor section provided with a monitor section, and the filter section is provided with a monitor wood having the same or similar properties as the wood connected to the decompression line,
The monitor unit may be provided with a monitoring window at a position where the liquid that has passed through the monitor member drips to visually check whether or not the liquid has passed through the monitor member. The wood to which this invention can be applied is not particularly limited, but for example, cedar, red pine, black pine, Japanese pine, Ezo pine, Todomatsu, toga, fir,
Coniferous trees such as cypress, sawara, spruce, ichii, and asunaro, makanba, beech, zelkova, oak, maple, shinanoki, elm, Japanese oak, sawtooth oak, nara, shinoki, cherry tree, horse chestnut, paulownia, katsura, lauan , mahogany apitone, agathis, teak, oak, rosewood,
Hardwoods such as ebony can be mentioned. Further, the shape of the material to be treated may be any shape as long as it can be loaded into a container, such as a log, veneer, square timber, or board. The materials to be treated include sawnwood as mentioned above, as well as
Processed wood such as plywood, glulam, particle board, and fiberboard may also be used. Examples of flame retardant treatment liquids include diammonium hydrogen phosphate, inorganic water-soluble salts such as boric acid, sulfamates, halogen compounds, compounds containing phosphorus and nitrogen, guanidine compounds, and metals such as antimony oxide. Materials containing flame retardants such as oxides can be used.

Examples of treatment liquids for dimensional stabilization include polyethers such as polyethylene glycol and polypropylene glycol, polyethylene glycol mono(meth)acrylate, saturated polyester resins, poly(meth)acrylates, or copolymers thereof. , urethane resin, polyvinyl alcohol, paraffin, vinyl acetate copolymer, polyamide resin, polyimino resin, aminoblast resin,
Fluororesin, silicone resin, vinyl copolymer resin, SB
Solutions or dispersions of R, NBR, etc. can be used. Treatment liquids for strengthening include, for example, styrene, (meth)acrylate, vinyl acetate, diallylphthalate,
Monomers represented by divinylbenzene, (meth)acrylic acid, acrylonitrile, vinylidene chloride, unsaturated polyester resins and styrene monomers, reactive polyurethane resins, phenolic resins, alkyd resins, urea resins, melamine resins, vinyl esters, epoxy resins, etc. solutions or dispersions can be used.

Examples of preservative treatment agents include copper compounds, chromium compounds, arsenic compounds, boron compounds, bentachlorphenol, naphthenic acid metal salts, organotin compounds, chlornaphthalenes, 8-quinolinol copper, cabtans, creonut oil, Examples include processing solutions containing preservatives such as Wolman's salt and chromated zinc chloride. Treatment liquids for insect repellent include, for example, Wolman salt, bolidene salt, organophosphorus, carbamate, organotin compounds, chlordane, heptachlor, deirdrin, aldrin, thiodane, γ-BHC (1,2,3,4,5 .6
-hexachlorocyclohexane), DDT [1,l
, 1-trichloro-2,2-bis(p-chlorophenyl)ethane], methoxychlor [1, 1 . 1-
Examples include treatment agents containing insect repellents such as trichloro-2,2-bis(p-methoxyphenyl)ethane], toxaphene, kebone, sulfonamides, thiophene oil, and organic thiocyanates. As a treatment solution for staining, for example, chrysophenin G
Direct tJ like X, Direct Brown M, etc.? 2 N,
Acidic dyes such as Suminol Fast Orange PO and Suminol First Brown R, basic dyes such as safranin and auramine, alcohol-soluble dyes, oil-soluble positive dyes, and dyeing aids and surfactants as necessary. Examples include solutions or dispersions containing the same. Examples of media for creating these treatment solutions include:
Water, alcohols, glycols, aromatic hydrocarbons,
Aliphatic hydrocarbons, alicyclic hydrocarbons, ketones, esters, halogen compounds, acids, dioxane, tetrahydrofuran, DMF, DMSO, etc. are used.

The viscosity of the treatment liquid used in the present invention is determined in relation to the properties of the wood to be treated, but generally a viscosity of 1,000 cps or less is preferred. The reduced pressure treatment in the method of the present invention is preferably performed at an absolute pressure of 160 Torr or less.

At higher absolute pressures, it may be difficult to efficiently remove gases present in the wood being treated. The pressure treatment in the method of the present invention includes a pressure of 1 to 50 Kg/crry',
In particular, it is desirable to carry out the process at a pressure of 8 to 50 kg/Crrf. The higher the degree of pressure, the better the ability to inject the treatment liquid into the wood to be treated. However, depending on the properties of the wood being treated, it may become deformed depending on the applied pressure, so care must be taken. The monitor wood is used to preferentially discharge air present in the treatment liquid or remaining on the surface of the treated wood to the outside of the system.
As mentioned above, this mechanism is provided to confirm that the treatment liquid has penetrated into the wood, but the mechanism behind this is not clear.
It is speculated that the conduit pores in the monitor wood pieces play the role of a filter that separates low-molecular substances such as air from high-molecular substances. Of course, it is preferable that the wood pieces are of the same species as the wood to be treated, but any wood pieces that are similar can be used.

[Effect]

First, the powder material to be injected is mounted on a truck, the truck is housed in the tank, and the tank is filled with liquid. Then, the air inside the tank is sucked by a vacuum suction means to reduce the pressure inside the tank. Then, the air present in the wood to be treated together with the air in the tank becomes L.
The recorded wood is discharged to the outside. Finally, when the inside of the tank is pressurized and the inside of the tank is opened to atmospheric pressure via a valve, the air present in the liquid in the tank or on the surface of the wood to be treated is discharged outside the tank. At the same time, the liquid is injected into the wood to be treated.

The same applies when using a monitor instead of a valve.
In this case, when most of the air in the tank is exhausted to the outside of the system, the injection liquid passes through the monitor powder and begins to drip into the monitor section of the monitor device. Since the monitor wood and the treated wood have the same or similar properties, if this dripping can be visually observed through the monitoring window of the monitor unit, it can be confirmed that the treatment liquid has sufficiently penetrated into the treated wood in the tank.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figures 1 to 4 show an embodiment of the present invention, and the apparatus for injecting liquid into wood according to this embodiment mainly consists of a pressure vessel 1 whose inside can be freely pressurized and depressurized, and a pressure vessel 1 to be treated. A trolley 3 for loading wood 2, a pressure reducing device 4 for reducing the pressure inside the pressure vessel 1, a pressurizing device 6 for supplying compressed air to the pressure reducing device Va4, and a pressure-feeding treatment liquid 20 into the pressure vessel 1. It consists of a pressurizing device 18 and a valve 7. The pressure vessel 1 consists of a hollow cylindrical body 8 and a lid 9 attached to one end of the body 8 so as to be openable and closable, and is fixed on a foundation with legs. A pressure reduction nozzle 10 and a pressure nozzle 11 are provided in the upper part of the shell 8. The pressure reduction nozzle 10 is connected to the pressure reduction device 4, and the pressure nozzle 11 is connected to the pressure device 18. Further, a processing liquid draw-out pipe 12 is provided at the bottom of the barrel 8 .

Note that a rail 15 for receiving the trolley 3 is provided inside the pressure vessel 1.

A rail 30 is laid on the M9 front side of the pressure vessel l. The truck 3 can be stored in the pressure vessel 1 and taken out from the pressure vessel 1 by a truck 31 running on the rails 30.

The trolley 3 carries the water material 2 to be treated.
It is designed to prevent the water material 2 to be treated from floating when placed in the container. Note that when the wood to be treated, especially the square timbers, are mounted on the trolley 3 in close contact with each other, for example, a small piece of wood is placed between each of the timbers to be treated 2 so that the air released from the timber 2 to be treated can easily escape to the upper part of the pressure vessel 1. It is best to sandwich the

However, in the case of logs, such processing is not necessary. Further, a processing liquid draw-out pipe 12 is provided at the bottom of the pressure vessel l. The pressure reducing devices 4 each vacuum-suction the air inside the pressure vessel 1 and discharge the air inside the pressure vessel 1 to the outside to reduce the pressure inside the pressure vessel 1, and also remove the air present inside the wood 2 to be treated. This is a vacuum suction means for discharging the treated wood 2 to the outside. ? The pressure device 4 is for vacuum suctioning the air inside the pressure vessel 1 to reduce the pressure inside the pressure vessel 1, and has a plurality of nozzle blocks 25 connected therein. As shown in FIG. 2, the nozzle block 25 is constructed by forming a throat 31 in a block body 26 and attaching a nozzle 33 to a front end opening 32 of the throat 31. The overall size is approximately 45 layers/■. The front end port 32 of the throat 31 expands toward the end, and the diameter D on the outer end side is set to the nozzle 3.
The daily diameter d of the nozzle hole 33a of No. 3 is set to D=1.5d, and the opening is separated from the tip of the nozzle nozzle 33 by a gap t (about 0.5 mm). Like the front end, the rear end of the throat 3l is flared toward the end and connected to the discharge hole 34. Nozzle 33
The base end of the block body 26 is screwed into a cavity 35 provided in the block body 26. A suction port 36 that opens inside this empty chamber 35
is connected to the intake hole 37. The nozzle 33 has a base end with a cylindrical portion 38 extending from the tip to a slight length (about 0.3+wm).
A conical part that spreads out from the base of 8 (length 2 in the axial direction)
■Extent).

In the nozzle block 25 shown in FIG. 2, a nozzle hole 33a is connected to an inflow hole 39 for compressed air. Compressed air inflow hole 3
9 is a discharge line 6 of the pressurizing device 6 (for example, a compressor)
1, and the intake hole 37 is connected to the pressure reduction nozzle 10 via a pressure reduction tank in the pressure reduction device. FIG. 3 shows test results of the pressure reduction effect of a pressure reduction device constructed using this nozzle block 25. Targets for decompression are 9
In the figure, a is a vacuum tank with 059 containers and 10 nozzle blocks are connected in parallel, b is 40 nozzle blocks, and C is 68 nozzle blocks in parallel. In addition, the straight line d-sentence shown as a comparative example is a one-hour line of decompression degree using a vacuum bomb manufactured by Sato Vacuum Machinery Co., Ltd. (address: 1036 Fujikubo, Miyoshi-cho, Iruma-gun, Saitama Prefecture). This straight line d-sentence was calculated from the performance graph shown in FIG. In the figure, the numbers in SW and ST indicate the exhaust speed (4/sin), and the numbers in KS indicate 1/100 of the exhaust speed (1/rain).

When 68 nozzle blocks 25 are connected (curve C),
It can be seen that compared to vacuum pumps of similar price (indicated by straight lines h and i in Fig. 3), it exerts a considerably stronger vacuum suction force. That is, by using this nozzle block 25, a vacuum suction force equivalent to that of an expensive vacuum pump can be obtained at a low cost, and the price of the entire system can be reduced. In addition, vacuum pumps generally require regular maintenance in order to maintain their performance, but if this nozzle block 25 is used, they can be made maintenance-free. Further, since the number of connections of the nozzle block 25 can be adjusted freely, a desired vacuum suction force can be easily obtained, and the system configuration can be easily varied.

The pressurizing device 6 is connected to the pressure reducing device 4 and supplies compressed air for vacuum suction to the pressure reducing device 4. The pressurizing device [18 is connected to the pressurizing nozzle 11 on one side and the reserve tank 19 for the processing liquid 20 on the other side, and the valve 7 is connected to the processing liquid draw-out pipe 12 provided at the lower part of the pressure vessel l. The treatment liquid 20 in the pressure vessel 1 is opened to the atmosphere, and air bubbles present in the treatment liquid 20 or attached to the surface of the wood 2 to be treated are discharged to the outside of the pressure vessel 1. This valve 7 is opened slightly by manual operation or by being operated intermittently using a solenoid valve. Further, a discharge pipe 71 is connected to the valve 7, and the other end of this discharge pipe 71 faces into a discharge tank 72. Note that the discharge tank 72 is connected to the reserve tank 19 so as to return the processing liquid 2o to the reserve tank 19. Next, the operation of this embodiment will be explained. First, an appropriate number of treated water materials 2 are mounted on the trolley 3, and the treated wood 2 is fixed. Then, the trolley 3 is moved to the trolley 31. Store it in the pressure vessel 1 using the rail 15 and close the lid 9. In this state, the processing liquid 20 is injected into the pressure vessel l. After injection, the treatment liquid 20 is poured until the wood 2 to be treated does not come out above the liquid level. Next, the pressurization device 6 is operated and the pressure reduction device 4 is operated to reduce the pressure inside the pressure vessel 1 to 160 Torr or less using the pressure reduction nozzle 10 at the upper part of the pressure vessel 1. From the time when the inside of the pressure vessel 1 exhibits the desired reduced pressure state, 10 to 12
Continue decompression for 0 minutes. As a result, the air inside the wood 2 to be treated is discharged to the outside.

Next, the pressure reduction nozzle 10 at the top of the pressure vessel 1 is closed, and the pressure is increased to 8 to 40 by the pressure nozzle 11 at the top of the pressure vessel 1.
A compressed processing liquid 20 of Kg/cm'' is sent into the pressure vessel l.The pressurization by this compressed processing liquid 20 is approximately 10-
Continue for 120 minutes. At the same time as the pressure inside the pressure vessel 1 is increased, the inside of the pressure vessel 1 is opened to atmospheric pressure by slightly opening the valve 7 manually or by opening it intermittently using a solenoid valve. Air existing in the liquid in the container 1 or on the surface of the wood 2 to be treated is discharged to the outside of the pressure container 1. In this case, the processing liquid 20 is discharged to such an extent that the pressure within the pressure vessel 1 does not drop suddenly. The discharged processing liquid 20 is led into a discharge tank 72 via a discharge pipe 71. Further, the processing liquid 20 in the discharge tank 72 returns to the reserve tank 19 and circulates therein. Thereafter, after stopping the operation of each device and returning the pressure inside the pressure vessel l to normal pressure, the lid 9 is opened and the cart 3 is pulled out, allowing the liquid-injected wood to be taken out. When liquid was injected into beech wood using the apparatus of this example, the injection rate of the treatment liquid was 115 to 129% by weight (average value 121% by weight). With conventional methods and equipment, the amount is at most 70 to 80% by weight. Figures 5 and 6 show other embodiments. In this embodiment, a pair of processing liquid conduits 13.14 are connected to the processing liquid withdrawal pipe 12 in place of the valve 7 connected to the processing liquid withdrawal pipe 12 in the above embodiment, and these pair of processing liquid conduits 13.1 are connected to the processing liquid withdrawal pipe 12.
4 are connected to the pressure reducing device 5 with monitor devices 170 and 170 interposed in between, respectively. The pressure reducing device 5 removes the processing liquid 20 in the pressure vessel l by vacuum suction.
is sucked into the treatment liquid 20 or the water material 2 to be treated.
This is a vacuum suction means for discharging air bubbles attached to the surface of the pressure vessel 1 to the outside of the pressure vessel 1. The monitor device 170 includes a filter section 171 connected to the processing liquid conduit 13 (14), and a monitor section 17 integrally attached below the filter section 171.
It consists of 2. FIG. 6 is a detailed view of the monitor device.

The filter section 171 is connected to the treatment liquid conduit 13 (14) and has monitor wood 173 having the same or similar properties as the wood 2 to be treated. The piping of the liquid to be treated conduit 13 (14) is connected to the filter section 171.
A decompression line is connected to a drain 174 attached to the side of the monitor section 172. The filter section 171 and the monitor section 172 are separated by a base plate 175, but are communicated with each other by a connecting pipe 177 passing through the base plate 175. A monitor lumber 173 is removably fixed to the upper end of the connecting pipe 177 by a pressing member 178, and closes the upper end opening of the connecting pipe 177.
Therefore, the air that has entered the filter section 171, the processing liquid 2
0, if it does not pass through this monitor member 173, the monitor section 17
I can't get out within 2. The monitor section 172 includes the monitor wood 1
A monitoring window 1 is installed at the position where the processing liquid 20 that has passed through the filter 73 drips.
76 so that it can be visually checked whether the treatment liquid 20 has passed through the monitor wood 173 or not. The monitor device 7 is also provided with a pressure gauge 180 and a drain hole 182. In the illustrated example, there is a pair of monitor devices, but of course only one monitor device is required.

Then, at the same time, the processing liquid 20 compressed by the pressure nozzle 11 of the pressure vessel 1 is sent into the pressure vessel 1, and at the same time, the pressure reducing device 5
The processing liquid 20 in the pressure vessel 1 is sucked through the processing liquid draw-out pipe 12 on the lower side of the pressure vessel 1 at a pressure lower than that in the pressure vessel 1 (approximately 60 Torr). As a result, air adhering to the treatment liquid 20 and the surface of the wood 2 to be treated is sucked into the monitor device 170 via the treatment liquid conduits 13 and 14. In this case, when the inside of the pressure vessel 1 is pressurized, the processing liquid 20 is under reduced pressure, so the monitor device 51 is on the low pressure side.
It flows towards 70. At this time, the accumulated air in the treatment liquid 20 and the residual air in the wood to be treated 2 are lighter and have better fluidity, so the monitor wood 17 is
3, passes through the monitor wood 173, and connects to the connecting pipe 177.
It escapes into the monitor section 172 through. As the pressurized injection further progresses, the processing liquid 2 flows into the monitor section 172.
0 is observed through the monitoring window 176. At this point, it can be confirmed that the treatment liquid 20 has completely penetrated into the wood 2 to be treated loaded in the container 3. [Effects of the Invention] According to the present invention, because of the above-mentioned precautions, a good liquid injection effect can be obtained even though the wood is immersed in the treatment liquid before the tank is depressurized, and moreover, the treatment process will decrease. In addition, since the liquid in the tank is sucked through a monitoring device, it is possible to extract the air in the liquid or the air attached to the wood surface, and the status of liquid injection into the wood can be monitored while the device is running. This has the effect of being able to be confirmed visually.

[Brief explanation of drawings]

FIG. 1 is an apparatus configuration diagram of an embodiment of the present invention, and FIG. 2 is a
FIG. 3 is a graph showing the capacity of the nozzle block of FIG. 2; FIG. 4 is a graph showing the vacuum pump pumping speed curve for calculating FIG. 3; FIG. 5 is a device configuration diagram showing another embodiment, and FIG. 6 is an enlarged sectional view of the monitor device. 1: Pressure vessel 2: Water material to be treated 3 containers 4, 5; Pressure reducing device 6: Pressurizing device
7: Valve 13, 14: Processing liquid conduit 20: Processing liquid 25: Nozzle block l70: Monitor device ii! i 171: Filter part l72: Monitor part 173: Monitor wood l76: Monitoring window

Claims (4)

[Claims] (1) A method of injecting a liquid such as resin liquid into wood in a tank whose interior can be depressurized or pressurized, and which consists of the following steps: a) Place the treated wood to be injected on a cart. Equipped with
a step of storing the cart in the tank and then filling the tank with the liquid; b) vacuum suctioning the air in the tank to reduce the pressure in the tank; and the wood to be treated together with the air in the tank; c) After the completion of the depressurization, the liquid is introduced into the tank using a pressure pump to pressurize the tank, and the liquid in the tank is released by a valve. injecting the liquid into the treated wood while releasing the tank to atmospheric pressure through the tank and discharging residual air present in the liquid in the tank or on the surface of the treated wood to the outside of the tank; (2) Instead of the step of releasing the liquid in the tank to atmospheric pressure via a valve, a vacuum suction line from inside the tank is provided separately from the vacuum suction line, and a vacuum suction line is provided from inside the tank that is the same as or similar to the wood to be treated. It is characterized by comprising the step of interposing a monitor wood having the following properties, sucking the inside of the tank by vacuum suction, and discharging air present in the liquid or on the surface of the wood to be treated to the outside of the tank. The method for injecting liquid into wood according to claim (1). (3) A device for injecting liquid such as resin liquid into wood,
Consisting of the following requirements: a) A tank whose interior can be depressurized or pressurized, b) A trolley for loading and storing the treated wood to be injected with the above-mentioned liquid, and c) Inside the above-mentioned tank. d) Vacuum suction means for reducing the pressure inside the tank by vacuum suctioning the air, discharging the air in the tank to the outside of the tank, and discharging the air present in the wood to be treated to the outside of the wood; d) A valve is provided to open the liquid in the tank to atmospheric pressure and discharge air bubbles present in the liquid or attached to the surface of the wood to be treated to the outside of the tank. (4) Instead of the valve, a monitoring device is interposed in the middle of the vacuum suction line that sucks the inside of the tank, and the monitoring device is connected to a filter section connected to the decompression line and below the filter section. and a monitor section provided integrally, and the filter section is provided with a monitor wood having the same or similar properties as the wood connected to the decompression line,
Claim 3: The monitor unit is provided with a monitoring window at a position where the liquid that has passed through the monitor member drips, for visually observing whether or not the liquid has passed through the monitor member.
) A device for injecting liquid into wood.