KR101664373B1 - Method for drying domestically produced wood using check of water content - Google Patents

Abstract

The present invention minimizes drying defects caused by deformation of wood and prevents sudden changes in the water content inside and outside of the wood and sudden changes in the surrounding environment to prevent the wood from being heated or twisted smoothly during the early and late stages of drying, The present invention relates to a domestic wood drying apparatus using a water content rate check that smoothly performs disinfection and disinfection. The wood drying apparatus includes a door on the front surface thereof, a bogie having a plurality of through holes in the center thereof, A drying chamber for enclosing the wood in a sealed state; A heater installed in the drying chamber and generating heat to dry the wood; An air circulation fan installed inside the drying chamber and circulating the air inside the drying chamber; A vacuum pump installed outside the drying chamber through a connection pipe communicating with the drying chamber and discharging air inside the drying chamber to the outside to form a vacuum inside the drying chamber; The steam generator is installed outside the drying chamber through a steam injection pipe connected to the drying chamber. The steam is injected into the drying chamber through the steam injection pipe to steam and preheat the wood. A steam generator; A magnetron disposed at a lower portion of the drying chamber in correspondence with the through holes and connected to the power supply to generate microwaves while being supplied with power; A microwave generator having a waveguide connected at the other end to the lower portion of the through-hole through the drying chamber; And a controller for controlling the operation of the heater and the microwave generating unit so that the moisture is dried at a set moisture content, and the humidity sensor is connected to the humidity sensor installed in the drying chamber to receive humidity information of the inside of the drying chamber through the hygrometer, Controller to control; .

Description

[0001] METHOD FOR DRYING DOMESTICALLY PRODUCED WOOD USING CHECK OF WATER CONTENT [0002]

The present invention relates to a domestic wood drying method and apparatus for drying wood, and more particularly, to a wood drying method and apparatus for drying wood by minimizing drying defects caused by deformation of wood during drying of the wood, The present invention relates to a domestic wood drying method and apparatus using a moisture content check to smoothly prevent wood from being twisted or twisted due to rapid changes in the environment surrounding China and to ensure sterilization and disinfection of wood inside during drying.

In general, wood has a relatively high moisture content at logging. If you make a product using the same timber as the timber, the product will be deformed over time. Thus, timber that has been cut requires an appropriate drying process.

Drying methods of wood include natural drying and hot air drying. Natural drying is a method in which wood is piled up in a drying area and drying is carried out using atmospheric temperature, humidity and wind. There is a drawback that drying time is long and a wide drying area is needed and drying is not possible below the Ki-Gun moisture content. On the other hand, the hot-air drying is a method of drying by adjusting the drying conditions such as the temperature, humidity and wind speed of the drying chamber artificially, the drying time is relatively short,

When wood is subjected to a drying process, water content decreases drastically and water absorption becomes low, and hemicellulose, which is food for bacteria among the constituents of wood, is decomposed, making it difficult for colostrum to live. Thus, drying of the wood can greatly improve the durability of the wood. Recently, timber has been dried and used for various purposes.

As a conventional apparatus for drying wood, for example, an apparatus in which an electric heater is directly installed in a drying chamber to heat internal air, or air heated through a hot air blower that generates heat from a combustion apparatus is introduced into a drying chamber A device for injecting the superheated steam into the drying chamber, an apparatus for injecting the superheated steam into the drying chamber, an apparatus for injecting the heated medium into the drying chamber by indirectly heating the air in the drying chamber after heating the heating medium in the combustion chamber, And a device for heating by high frequency.

On the other hand, the pine tree reeducation which is recently invented in the domestic wood is a parasitic nematode propagated by the pine tree beetle, which is currently a suitable parasite nematode, and there is no nematode for the pineapple. Once infected, 99.9% . Pine wilt disease was first discovered in Japan in 1905, but only in 1972, the pest was found to be a pine creeper, and it is now known that most of the pine forests in Japan are dead. Since then, the international trade has been spreading throughout Asia and the world.

In China, it has been spreading since the epidemic was confirmed in 1982 in Nanjing, and it was reported that in Taiwan, the epidemic occurred in 1985. In Korea, it was first reported at Geumjeongsan in Busan in 1988 and spread to Gyeongbuk area for more than 10 years. In order to prevent eradication and spread of pine tree disease, the Korean Forest Service has been putting huge budget and manpower every year, but the number of damaged areas and dead wood is increasing every year.

It has a size of less than 1 ㎜, and at 25 ℃, the first generation and the required days are only 4 ~ 5 days. One pair will grow to 200,000 after 20 days to block the water rise by obstructing the host plant, and secrete the toxin, Cellulase, to destroy the tissue and destroy the host plant. The reedbill of the pine tree is transmitted to the pine tree through the pupa through the larva of the pine tree. This is the special symbiotic relationship that gives the rehabilitation without the ability to move the magnet to the host plant and the rehabilitation of the rehabilitation of the pine tree to provide the spawning ground of the pine tree.

For almost 30 years, many studies have been carried out with the aim of controlling the pine wilt disease as a main target, but the development of a direct inhibitor against the pine re-growth using the biological approach is very insufficient.

Presently proposed methods for the control of pine nutcracker disease include methods of control by felling and fumigation, control by felling and crushing, and control by felling and incineration. Among them, the control method by the felling and fumigation is a method of controlling the fungus by fumigation such as metamsodium after cutting the damaged tree by the pine wilt disease bottle.

However, the above-described conventional techniques have the following problems.

The wood which is dried by the conventional wood drying apparatus has a problem that the surface of the wood is severely broken due to the difference in water content between the inside and the outside of the wood and the difference in the ambient temperature,

In addition, the wood which is dried by the conventional wood drying apparatus can not be dried in the same or the same moisture content as the inside and the outside of the wood. Especially, the inside of the wood can not be dried smoothly, Or twisted or warped.

In addition, the conventional wood drying apparatus has problems such as insufficient drying of the interior of the wood, insect pests and bacteria remaining in the interior of the wood, and infection of other wood at the time of use.

In other words, methosodium, a recombinant insecticide, is expensive and harmful to humans and livestock. The control method by cutting and crushing is a method of cutting dead wood by pine tree re-infestation bottle and crushing it to a thickness of 6 mm or less so that the larvae of the bees can not live. The control method by cutting and incineration is a method It is a way to build up a tree and then burn it. In order to control by the above method, it is necessary to transport the fallen tree to the place where the machine for crushing is installed or the place where the incinerator is installed, because the damaged tree or dead wood is infested with larvae of rehabilitation and infestation. During the process, there is a risk that the larvae and re-insects of the insects will spread to other trees.

In addition, in case of incineration, the control period is very limited due to forest fires. In case of burning in forest land, there is a problem of generating heat loss and killing the surrounding pine trees. Above all, the above-mentioned control methods are post-treatment methods aiming at preventing further spread of pine tree rehabilitation by fumigation, crushing or incineration of damaged trees caused by pine tree rehabilitation bottles, There is a fundamental problem that it is not a method to prevent reinfection or to treat and revive infected pine trees.

Direct control of pine tree reforestation is the only way to inject preventive medicine into living pine trees.

Open Patent No. 1996-0024197 "Wood drying method and drying apparatus" (July, 20, 1996)

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art,

It is an object of the present invention to minimize the drying defects caused by the deformation of the wood caused by the drying of the wood and to smoothly cause the wood to be twisted or twisted due to the difference in water content between the inside and the outside of the wood and the sudden change in the surrounding environment The present invention also provides a domestic wood drying method and apparatus using water content check that smoothly sterilizes and disinfects the inside of the wood during drying.

It is another object of the present invention to provide a domestic wood drying apparatus using a moisture content check to seal a magnetron through a closed case so that equipment can be smoothly protected.

It is another object of the present invention to provide a domestic wood drying apparatus using a moisture content check to cool the magnetron to prevent shortening of the service life of the magnetron due to the heat of the drying chamber and the magnetron itself.

In order to achieve the above object, a domestic wood drying apparatus using a moisture content check according to the present invention comprises a door having a front surface, a bogie having a plurality of through holes at the center thereof, A drying chamber for enclosing the loaded wood in a sealed state; A heater installed in the drying chamber and generating heat to dry the wood; An air circulation fan installed inside the drying chamber and circulating the air inside the drying chamber; A vacuum pump installed outside the drying chamber through a connection pipe communicating with the drying chamber and discharging air inside the drying chamber to the outside to form a vacuum inside the drying chamber; The steam generator is installed outside the drying chamber through a steam injection pipe connected to the drying chamber. The steam is injected into the drying chamber through the steam injection pipe to steam and preheat the wood. A steam generator; A magnetron disposed at a lower portion of the drying chamber in correspondence with the through holes and connected to the power supply to generate microwaves while being supplied with power; A microwave generator having a waveguide connected at the other end to the lower portion of the through-hole through the drying chamber; And a controller for controlling the operation of the heater and the microwave generating unit so that the moisture is dried at a set moisture content, and the humidity sensor is connected to the humidity sensor installed in the drying chamber to receive humidity information of the inside of the drying chamber through the hygrometer, Controller to control; .

The microwave generating unit of the domestic wood drying apparatus using moisture content check according to the present invention further includes a closed case installed on a lower surface of the drying chamber to enclose and enclose the magnetron and the wave guide, The drying chamber is characterized in that a reflective material for reflecting microwaves is applied to the inner surface thereof.

The microwave generating unit of the domestic wood drying apparatus using the moisture content check according to the present invention may further include a cooling pipe stacked on the enclosure, one end of the cooling pipe connected to the other end of the cooling pipe, And a water pump installed on the pipe of the cooling pipe outside the closed case and for flowing the cooling water.

In order to achieve the above object, a "domestic wood drying method using water content check" according to the present invention is a method of drying domestic wood in a state where wood is mounted in a drying chamber, closing the drying chamber, Boiling and preheating the wood by injecting steam into the chamber to preheat the wood; A steam discharging and vacuum forming step of stopping the operation of the steam generator and discharging steam and air inside the drying chamber to the outside while vacuuming the inside of the drying chamber, ; Drying the outer surface of the wood by heating the inside of the drying chamber by operating the heater and the air circulation fan inside the drying chamber when the formation of vacuum is completed inside the drying chamber; Drying the interior of the wood by stopping the operation of the heater and activating the microwave generator to irradiate microwave to the interior of the drying chamber from the lower part of the drying chamber toward the wood; The humidity of the wood before drying is measured in advance in the drying chamber through a hygrometer installed in the drying chamber, the humidity of the interior of the drying chamber is measured, and the humidity before drying of the wood and the humidity of the drying chamber A moisture content calculating step of calculating a present moisture content of the wood by performing a comparative analysis; The drying of the outer surface of the wood, the drying of the interior of the wood, and the calculation of the water content are repeatedly performed in a state in which the air circulation fan is continuously operated to dry the outer surface of the wood and the interior thereof Alternately repeating the steps of: .

As described above, the present invention minimizes drying defects caused by deformation of wood during drying of wood, and prevents the wood from being heated or twisted due to a difference in water content between the inside and outside of the wood and a sudden change in the surrounding environment And the sterilization and disinfection of the interior of the wood can be smoothly performed at the time of drying, and thus the defective rate of the dried wood is minimized, so that the safety of the wood from the insect infection is remarkably improved.

Further, according to the present invention, the magnetron is hermetically sealed through the closed case, so that the equipment can be smoothly protected.

Further, the present invention has the effect that the magnetron is cooled to shorten the service life of the magnetron due to the heat of the drying chamber and the magnetron itself, and to prevent breakdown smoothly.

1 is a schematic front sectional view of a domestic wood drying apparatus according to the present invention,
Fig. 2 is an enlarged view of the main part of Fig. 1,
3 is a schematic side cross-sectional view of a domestic wood drying apparatus according to the present invention,
4 is an enlarged view of the main part of Fig. 3,
5 is a view showing a domestic wood drying method according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

FIG. 1 is a schematic cross-sectional view of a domestic wood drying apparatus according to the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, FIG. 3 is a schematic side cross-sectional view of a domestic wood drying apparatus according to the present invention, 3 is an enlarged view of the main part of Fig.

As shown in the drawings, the domestic wood drying apparatus according to the present invention includes a hollow cylindrical drying chamber 10, a heater 20 installed inside the drying chamber 10, A vacuum pump 40 connected to the drying chamber 10, a steam generator 50 installed in the drying chamber 10, and an air circulation fan 30 installed in the drying chamber 10, A microwave generating unit 60 provided at a lower portion thereof, and a controller 70 for controlling all the devices.

The drying chamber 10 is provided in the shape of a hollow cylindrical pressure vessel and has a door 12 on the front side and a bogie 12 having a plurality of through holes 12a at the center. In a state in which the wood is stacked in a closed state.

The door 11 opens and closes the front surface of the drying chamber 10. The door 11 opens the door 11 after entering the drying chamber 10, ) To close the drying chamber (10).

The bogie 12 is horizontally moved along the rails provided on the bottom surface of the drying chamber 10 so that the bogie 12 can move from the outside to the inside of the drying chamber 10 or from the inside to the outside of the drying chamber 10, (W) can be easily transferred.

The through hole 12a is formed such that the microwave generated from the microwave generating part 60 is transmitted to the bogie 12 through the through hole 12a, To be irradiated onto the wood (W) loaded on the truck (12).

It is preferable that the drying chamber 10 is coated with a reflective material for reflecting microwaves on the inner surface of the drying chamber 10. This is because microwaves irradiated by the microwave generation unit 60 from the inner lower side to the upper side of the drying chamber 10 Is reflected by the inner surface of the drying chamber (10) and can be injected back into the wood (W). Here, the reflective material may be, for example, aluminum powder or aluminum foil, and the aluminum powder is applied in combination with the heat resistant adhesive and the aluminum foil is adhered to the inner surface of the drying chamber 10 with a heat resistant adhesive.

The heater 20 is installed inside the drying chamber 10 and generates heat for drying the wood W. The heater (20) can be used with various heaters including electric heaters. Here, the heater 20 heats the outer surface of the wood W to dry the outer surface of the wood.

The air circulating fan 30 is installed inside the drying chamber 10 and circulates the air inside the drying chamber 10 so that heat generated by the heater 20 smoothly flows to the wood So that they can be uniformly transmitted. The plurality of air circulation fans 30 are installed in the drying chamber 10.

The vacuum pump 40 is installed outside the drying chamber 10 through a connection pipe 41 communicating with the drying chamber 10 and is connected to the drying chamber 10 through the connection pipe 41. [ 10, and discharges the air to the outside, thereby forming a vacuum inside the drying chamber 10.

That is, the vacuum pump 40 functions to discharge the unnecessary gas inside the drying chamber 10 to the outside, and to make the inside of the drying chamber 10 to a vacuum state as necessary. When the interior of the drying chamber 10 is evacuated as described above, when the wood W is heated by the heater 20, the moisture inside the wood W is discharged relatively quickly and easily to the outside .

The steam generator 50 is installed outside the drying chamber 10 through a steam injection pipe 51 connected to the drying chamber 10 and is used for steam cooking and preheating of the wood W And injects steam into the drying chamber 10 through the steam injection pipe 51.

When steam is injected into the drying chamber 10 by the steam generator 50, the wood W is steamed by the steam, so that the wood itself is preheated and dried at a relatively high temperature When the wood is dried by the temperature, it is prevented smoothly at the early stage of the drying of the wood due to the sudden pressure or temperature change.

The microwave generating unit 60 includes a power supply 61 installed at a lower portion of the drying chamber 10 and a plurality of microwave generating units 60 at a lower portion of the drying chamber 10 corresponding to the through holes 12a, A magnetron 62 connected to the feeder 61 and generating power by being supplied with power and a magnetron 62 having one end connected to the magnetron 62 and the other end passing through the drying chamber 10, And a waveguide 63 corresponding to the waveguide 63.

The microwave generating unit 60 generates a microwave by the magnetron 62 by the supply of power through the power supply 61 and the generated microwave is transmitted through the wave guide 63 to the through hole 12a And irradiates the lower part of the wood loaded on the carriage 12 to heat the inside of the wood W by microwaves to dry the inside of the wood.

In addition, the micro-generator 60 heats the moisture in the wood through microwaves, thereby removing insects and germs remaining in the wood, thereby easily sterilizing the wood as a whole.

The power supply 61 is a known power distributor capable of simultaneously supplying a constant power to the plurality of magnetrons 62. The magnetron 62 is a well-known electronic component that generates microwaves by supplying power. The waveguide 63 is a known means for moving the microwave generated by the magnetron 62.

 The wood drying apparatus dries the outer surface of the wood W by the heater 20 and dries the inside of the wood W by the microwave generating unit 60, It is possible to prevent dryness and warping during drying due to a difference in water content between the inside and the inside, and to produce dry wood with excellent quality.

The microwave generating unit 60 further includes a sealing case 64 installed on a bottom surface of the drying chamber 10 to hermetically surround and enclose the lower ends of the magnetron 62 and the wave guide 63. The sealing case 64 surrounds the magnetron 62 and the waveguide 63 to protect the magnetron 62 and the waveguide 63 and forms a closed space around the magnetron 62 and the waveguide 63.

The microwave generating unit 60 includes a cooling pipe 65 stacked inside the enclosure 64 and spaced apart from the magnetron 62 and a cooling pipe 65 disposed outside the enclosure 64, A cooler 66 connected to one end of the cooling pipe 65 so as to allow water to flow therein and to cool the water contained in the cooling pipe 65; And a water pump (67) for flowing the cooling water.

The cooling pipe 65 is a cooling water circulation pipe through which the water cooled by the cooler 66 is circulated by the operation of the water pump 67. The cooling pipe 65 cools the inside of the enclosure 64 with cooling water, The heat generated in the magnetron 62 itself or the generated heat generated by the heater 20 is transmitted to the magnetron 62 through the waveguide 63 in the drying chamber 10 Thereby cooling the heat and remarkably extending the service life of the magnetron 62.

Although the cooling pipe 65 is illustrated as being disposed inside the enclosure 64, the present invention is not limited thereto and may be disposed on the outer surface of the enclosure 64.

The controller 70 is connected to a hygrometer 71 installed in the drying chamber 10 and receives humidity information of the inside of the drying chamber 10 through the hygrometer 71 to calculate the moisture content of the dried wood And controls the operation of the heater (20) and the microwave generating unit (60) so that the wood is dried at a predetermined moisture content.

That is, the controller 70 measures the humidity of the inside of the drying chamber 10 before the wood is dried, and then when the wood 20 is being dried by the operation of the heater 20 and the microwave generating unit 60 The humidity of the interior of the drying chamber 10 is measured to compare the humidity before drying of the wood with the humidity during drying to calculate the present moisture content of the wood.

At this time, the change in the humidity inside the drying chamber 10 due to the change of the water content due to the drying of the wood is measured and measured through experiments such as moisture content per unit weight and moisture of the wood beforehand, The controller 70 calculates and calculates the water content of the wood through the current humidity.

1 is a thermometer for measuring the temperature of the inside of the drying chamber 10.

Hereinafter, the operation of the present wood drying apparatus will be described. The door 11 is opened and the wood W in a luminescent state is mounted on the carriage 12 and mounted in the drying chamber 10 and then the door 11 is closed to close the drying chamber 10 .

In this state, the steam generator (50) is operated to inject steam into the drying chamber (10) to preheat the wood (W) while mixing. The operation of the steam generator 50 is stopped and the vacuum pump 40 is operated to discharge the steam in the drying chamber 10 to the outside while simultaneously discharging the steam in the drying chamber 10, Thereby forming a vacuum in the interior of the chamber.

The humidity in the drying chamber 10 is measured through the hygrometer 71 when the vacuum inside the drying chamber 10 is completed and the measured humidity is humidity information before drying of the wood, 70).

When the humidity is measured through the hygrometer 71, the controller 70 controls the heater 20 and the air circulation fan 30 to operate them, and accordingly, the heat generated by the heater 20 Is circulated in the drying chamber (10) by the air circulation fan (30), thereby drying the outer surface of the wood (W).

When the heater 20 is operated for a predetermined time and the outer surface of the wood is dried to some extent, the heater 20 is stopped and the magnetron 62 is driven through the power supply 61 to generate microwaves The generated microwaves are injected into the drying chamber 10 through the waveguide 63 and irradiated to the lower surface of the wood through the through holes 12a so that the moisture inside the wood is transferred to the microwave And the inside of the wood W is dried.

When the inside of the wood is dried for a predetermined time, the controller 70 measures the current humidity inside the drying chamber 10 through the hygrometer 71. At this time, the controller 70 compares and analyzes the moisture measured before drying of the wood with the humidity measured before and after drying the interior of the wood to calculate the current water content of the wood.

When the current water content of the wood reaches the preset moisture content, the drying operation is stopped. On the contrary, if the current water content of the wood does not reach the predetermined moisture content, the heater 20 and the magnetron 62 alternate So that the outer surface and the inside of the wood are dried again.

The controller 70 operates the heater 20 and the magnetron 62 to dry the wood until the wood reaches a preset moisture content in the order of outer surface, interior, and humidity of the wood, do.

The wood W is dried to a predetermined water content in a state that the outer surface and the interior of the wood W have a substantially similar water content and the wood is dried after the drying of the wood due to the water content difference between the inside and outside of the wood, And warpage and deformation are completely prevented, resulting in a very high quality dry neck.

5 is a view showing a domestic wood drying method according to the present invention.

As shown in the figure, the domestic wood drying method according to the present invention includes a step of ramming and preheating wood (S10) which boils and preheats the wood with steam, and a step of discharging the steam to the inside of the drying chamber, (S30) drying the outer surface of the wood through the heater, drying the inside of the wood through the microwave generating unit (S40), drying the inside of the wood through the microwave generating unit (S50) of calculating a moisture content, and an iterative execution step (S60) of alternately repeating the drying and moisture content calculation of the outside and inside of the wood.

In the step of ramming and preheating the wood (S10), the drying chamber is closed while the wood is mounted in the drying chamber, and the steam generator is operated to inject steam into the drying chamber. In this step, steam is injected into the drying chamber to pre-heat the wood by steaming with steam.

When the wood is matured and preheated by the steam, the wood can withstand the sudden change in temperature or pressure during the initial drying of the wood by the heater, so that the wood can be smoothly prevented from being twisted or twisted.

The steam discharging and vacuum forming step S20 is a step of stopping the operation of the steam generator when steam of the wood is completed and discharging the steam and air inside the drying chamber to the outside through a vacuum pump, To form a vacuum. This step is intended to allow subsequent drying of the wood to be carried out more smoothly through the discharge of the steam inside the drying chamber and the formation of a vacuum.

The step S30 of drying the outer side of the wood is a step of heating the inside of the drying chamber by moving the heater and the air circulation fan inside the drying chamber when vacuum formation is completed inside the drying chamber, Heat is applied to the outer surface of the wood to dry the outer surface of the wood.

The step of drying the inside of the wood (S40) is a step of stopping the operation of the heater and activating the microwave generator to irradiate the microwave toward the inside of the drying chamber from the lower part of the drying chamber. The inside of the wood is dried by heating the moisture inside the wood.

The water content calculating step S50 is a step of previously measuring the humidity of the wood before drying in the drying chamber through a hygrometer installed in the drying chamber and measuring the current humidity inside the drying chamber, And the current humidity of the drying chamber is compared and analyzed to calculate the present water content of the wood.

Thus, by calculating the present water content of the wood, it is possible to recognize whether the wood is dried at a predetermined water content set in advance.

The repeating step S60 may be repeatedly performed in a state where the air circulation fan is continuously operated to perform the drying step S30, the drying step S40 and the water content calculation step S50, Is carried out alternately to dry the outer surface and the inner surface of the wood until the desired moisture content is reached.

The drying of the outer surface and the drying of the inside of the wood are alternately performed continuously so that the moisture on the outer surface of the wood is removed so that the moisture inside the wood can smoothly flow to the outer surface of the wood. The wood is heated and dried, and this series of processes is repeated to evaporate moisture away from the inside of the wood. Accordingly, through the repetition process, the wood is dried in a state that the inside and the outside of the wood have almost the same moisture content, and the moisture inside the wood is heated to remove insects and bacteria remaining in the inside of the wood, It is easily disinfected as a whole.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is clear that the present invention can be suitably modified and applied in the same manner. Therefore, the above description does not limit the scope of the present invention, which is defined by the limitations of the following claims.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention.

10: Drying chamber
11: Door
12: Truck 12a: Through hole
20: Heater
30: Air circulation fan
40: Vacuum pump
41: Connector
50: Steam generator
51: steam injection pipe
60: Microwave generator
61: Power supply 62: Magnetron
63: waveguide 64: sealed case
65: Cooling tube 66: Cooler
67: Water pump
70: controller
71: Hygrometer

Claims (4)

delete delete delete A wood smelting and preheating step of closing the drying chamber while the wood is mounted inside the drying chamber and activating the steam generator to inject steam into the drying chamber so as to preheat the wood;
A steam discharging and vacuum forming step of stopping the operation of the steam generator and discharging steam and air inside the drying chamber to the outside while vacuuming the inside of the drying chamber, ;
Drying the outer surface of the wood by heating the inside of the drying chamber by operating the heater and the air circulation fan inside the drying chamber when the formation of vacuum is completed inside the drying chamber;
Drying the interior of the wood by stopping the operation of the heater and activating the microwave generator to irradiate microwave to the interior of the drying chamber from the lower part of the drying chamber toward the wood;
The humidity of the wood before drying is measured in advance in the drying chamber through a hygrometer installed in the drying chamber, the humidity of the interior of the drying chamber is measured, and the humidity before drying of the wood and the humidity of the drying chamber A moisture content calculating step of calculating a present moisture content of the wood by performing a comparative analysis;
The drying of the outer surface of the wood, the drying of the interior of the wood, and the calculation of the water content are repeatedly performed in a state in which the air circulation fan is continuously operated to dry the outer surface of the wood and the interior thereof Alternately repeating the steps of:
And drying the dried wood.

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