A device and method for hard wood cracking for a friction wood product

Abstract

A device and method for preventing cracking of hardwood in solid wood products are disclosed, relating to the apparatus and method used in the post-forming process of hardwood. It features a sealed chamber with walls forming a double-layered space, connected to a boiling water tank, a vacuum pump, etc. The cracking of hardwood is prevented using an "intermittent heating-vacuum (negative pressure)" method. The beneficial effects of this invention are: during the post-forming process of hardwood, this device and method significantly increases the rate of moisture movement from the core to the surface of the hardwood, substantially reducing the "higher inside, lower outside" moisture content gradient between the surface and core, thus eliminating quality problems such as surface hardening (internal cracking) during post-forming. Solid wood products manufactured using hardwood post-formed using this invention have a near-zero probability of cracking, warping, or other product quality problems in a "dry indoor environment."

Description

Technical Field

[0001] A device and method for preventing cracking of hardwood in solid wood products, which relates to a method for preventing quality problems such as surface hardening (internal cracking of wood) that easily occur in hardwood during post-forming treatment (hardwood material stability optimization treatment).

[0002] Hardwood refers to wood with an air-dry density typically around 0.65 g / cm³. 3 Purchased hardwood boards and squares are made from mature forest logs harvested at or above the mature forest level. The logs are sawn and dried (e.g., using steam drying kiln drying to control the moisture content of the sawn timber within the range of 6.0% to 11.0%). Alternatively, the boards and squares are further processed into finger-jointed hardwood boards (size range: length 2770mm x width 1240mm x thickness 9 to 25mm) through planing, splicing (transverse) and finger-jointing (longitudinal) processes. Background Technology

[0003] Solid wood furniture, solid wood wall panels, solid wood doors, and other solid wood products made directly from hardwood dried in a steam kiln with a moisture content mostly between 6.0% and 11.0% are prone to deformation (warping and corner curling) and cracking in the "dry indoor environment" (where the relative humidity of the indoor space is generally between 28% and 3%, and the equilibrium moisture content of the wood is 6.0% and 1%) during winter and spring when underfloor heating is used in the north or air conditioning is used in the south.

[0004] The air-dry density of woods such as cedar and pine is typically in the range of 0.28 g / cm³. 3 ~0.45g / cm 3 The timber used in artificially grown sapling lumber (also known as softwood, including finger-jointed boards made from small-diameter coniferous and broadleaf logs of equal or unequal width) is generally only about 15 years old, and the log diameter is relatively small (usually ≤300mm). The moisture content of lumber made from artificially grown sapling timber through processes such as steam kiln drying (including finger-jointed boards made from purchased timber and finger-jointed boards made from purchased small-diameter timber) is mostly between 6.0% and 11.0%. Using a post-forming treatment system (wood material stability optimization treatment system) that does not have the conditions for steaming (humidification), the moisture content of the wood in the above-mentioned artificial sapling wood boards can be optimized to 6.0% to 8.5%. This allows solid wood products made from artificial sapling wood boards to maintain a high degree of stability in their geometric shape and board surface quality, even in the "dry indoor environment" where underfloor heating is used in the north or heating and air conditioning are used in the south during winter and spring. Furthermore, during the post-forming treatment process (the process of further optimizing the wood material stability), because the wood density of artificial sapling wood is low, the water absorbed in the wood core is more easily moved (overflowed) and evaporated. At this time, artificial sapling wood boards generally do not have surface hardening quality defects.

[0005] However, due to its high density, hardwoods have significant challenges in the movement (overflow) and evaporation of water absorbed in the core. If the aforementioned wood stability optimization treatment system, which lacks humidification capabilities, is used to treat hardwoods, the large moisture content gradient between the system space and the hardwood will cause the surface water to evaporate (overflow) quickly into the system space. Meanwhile, the water in the core region, due to its high density and limited molecule movement (overflow) pathways, will move much more slowly towards the surface. This results in a large moisture content gradient between the surface and core, characterized by a "higher internal moisture content (higher water content in the core) and a "lower external moisture content (lower water content in the surface)" gradient, leading to high stress between the surface and core. This stress can easily cause surface hardening defects, primarily honeycomb-like internal cracks, during post-processing (hardwood stability optimization treatment). Honeycomb-like internal cracks typically run along the wood rays in the core of the wood, and are often difficult to detect by simply observing the surface of hardwood (hardwood planks, hardwood finger-jointed boards). Surface hardening defects not only jeopardize the entire reprocessing process of hardwood in the workshop, but this hidden danger also makes hardwood products with PVC veneer (impregnated film paper veneer, paint veneer) on the market show wood ray cracks to varying degrees. Especially in a dry indoor environment, the width and depth of wood ray cracks (wood surface hardening defects) in hardwood products may further increase.

[0006] To eradicate the quality problems of surface hardening (such as internal cracking) that easily occur in hardwoods during post-forming treatments (hardwood material stability optimization processes), it is necessary to significantly increase the rate of moisture movement from the hardwood core to the surface while simultaneously allowing water absorbed from the wood surface to evaporate (overflow) into the system space. This also requires substantially reducing the moisture content gradient between the hardwood surface and core, characterized by "higher moisture content in the core and lower moisture content in the surface," and significantly reducing the stress between the two regions. However, among the many factors affecting the rate of moisture movement from the wood core, the surrounding pressure is the most significant. Under constant temperature and humidity, the rate of moisture movement from the wood core increases sharply as the surrounding air pressure decreases. Heating the hardwood at a relatively low temperature under vacuum conditions can accelerate the movement of moisture from the hardwood core to the surface. Summary of the Invention

[0007] The technical problem this invention aims to solve is to provide a device and method that effectively prevents hardwood used in solid wood products from cracking during post-forming processes (hardwood material stability optimization treatments), addressing the above-mentioned shortcomings. The technical solution is as follows:

[0008] A device for preventing cracking of hardwood in solid wood products includes a sealed chamber. The key technology involves a sandwiched space formed by an outer steel plate and an inner steel plate in the walls of the sealed chamber. A water tank is installed on one side of the top of the sealed chamber, and an electric heater is installed at the bottom of the water tank. The outlet of the water tank is located within the sandwiched space of the sealed chamber. A water pipe is installed at the top of the water tank, with the other end connected to a hot water pump. A steam extraction pipe is installed on the other side of the top of the sealed chamber, with one end inserted into the interior space of the sealed chamber and the other end connected to a steam-water separator. The steam-water separator is connected to a vacuum pump via an outlet pipe. An air inlet steel pipe is installed near the steam extraction pipe at the top of the sealed chamber, with one end of the air inlet steel pipe located inside the sealed chamber. An electric heating device is mounted on the outer wall of the air inlet steel pipe.

[0009] Install a hot water pump at the other end of the water pipe.

[0010] Install a water tank control valve at the outlet of the water tank.

[0011] A drain valve is installed below the steam-water separator.

[0012] Install a second check valve on the intake steel pipe.

[0013] Install a fan on the ceiling inside the enclosed room.

[0014] Install the controller outdoors in a sealed environment.

[0015] The outer wall of the outer steel plate is covered with a first ceramic fiber cotton insulation layer, and the outer wall of the water tank is covered with a second ceramic fiber cotton insulation layer.

[0016] The key technology of the above-mentioned method for preventing hardwood products from cracking is as follows:

[0017] 1) Push the hardwood pile into the sealed room, then close the steel door tightly;

[0018] 2) The controller sets the operating time of the temperature and humidity instruments and the fan;

[0019] 3) The controller starts the electric heater to heat the tap water in the water tank;

[0020] 4) The controller opens the water tank control valve, and boiling water flows into the interlayer space. When the water temperature in the interlayer space drops to 65℃±2℃, the controller starts the hot water pump and makes the vacuum pump run. When the hot water pump is running, it draws all the hot water stored in the interlayer space back into the water tank through the water pipe to continue heating it into boiling water.

[0021] 5) The fan operates to transfer and balance the heat in the sealed room;

[0022] 6) When the vacuum pump is running, it extracts the hot and humid air from the sealed chamber through the steam extraction pipe, and the steam-water separation device condenses the water vapor in the hot and humid air into liquid water and discharges it.

[0023] 7) The controller opens the second check valve and the electric heating device. The hot and humid external air under normal pressure is heated and dehumidified when it passes through the intake steel pipe and becomes dry air before entering the sealed chamber space under negative pressure.

[0024] 8) The controller opens the water tank control valve to allow boiling water to flow back into the interlayer space, starting the next cycle;

[0025] 9) After several cycles, when the average moisture content of the wood in the sealed chamber has remained stable within the range of 30%±2%, the entire system operation ends and the hardwood pile is removed from the sealed chamber.

[0026] The core of the steel gate is a third ceramic fiber cotton insulation layer.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. Optimized processing results in high quality, fast speed, high efficiency, and low operating costs.

[0029] The "intermittent heating-vacuum (negative pressure)" technology device of this invention, in the post-forming treatment of hardwood (during the hardwood material stability optimization treatment process), significantly increases the movement speed of moisture from the hardwood core to the surface and substantially reduces the "high inside, low outside" moisture content gradient between the hardwood surface and core (substantially reducing the stress between the hardwood surface and core). This not only eliminates the quality problem of surface hardening (internal cracking, etc.) in hardwood during the post-forming treatment (hardwood material stability optimization treatment process), but also ensures that the moisture content of purchased hardwood with a moisture content range of 6.0% to 11.0% can be uniformly distributed within the range of 6.0% ± 1% after being optimized by this invention for 3 or 4 days and placed in a sealed chamber at 21.1°C. Moreover, the operating (energy consumption) cost of each piece of hardwood (size = 2770mm long x 1240mm wide x 18.0mm thick purchased hardwood finger-jointed board) is less than 0.75 yuan.

[0030] 2. Without using various metal stretching devices (straighteners), the probability of solid wood products (including wardrobe flat wooden doors with a height dimension of ≈2750mm) made from hardwood customized using the forming treatment (hardwood material stability optimization treatment) of this invention is close to zero in the market, especially in "dry indoor environments". The probability of wood cracking (such as honeycomb-like internal cracks in wood), deformation and warping, or "surface ribs (uneven defects on the product surface caused by slight shrinkage of wood cell volume)" is close to zero.

[0031] 3. In the process of "intermittent heating-vacuum (negative pressure)" shaping treatment (hardwood material stability optimization treatment) of hardwood, this invention can also improve the stability of some hardwood logs (such as those with a wood density ≥ 0.68 g / cm³). 3 When rubberwood (a type of timber) undergoes chemical preservative treatment at logging sites using methods such as soaking with boric acid or other chemical preservatives, harmful chemical solvents (liquid molecules) remaining in the hardwood fiber tissue, along with water molecules (absorbed water) in the hardwood, are forced to move and evaporate into the sealed chamber under the influence of temperature (heat), pressure (negative pressure), and wood moisture content gradients. This evaporates (overflows) and is then condensed into liquid water by the vapor-water separation device of this invention, before being discharged into an external ground drain through a drain valve. This significantly reduces the amount of harmful chemicals such as boric acid remaining in the hardwood fiber tissue treated with chemical preservatives and reduces the odor of acidity. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention;

[0033] Figure 2 ,yes Figure 1 Schematic diagram of AA structure. Detailed Implementation

[0034] See Figure 1 , Figure 2 A device for preventing cracking of hardwood in solid wood products is disclosed, comprising a sealed chamber 21.1. The key technology is that the walls of the sealed chamber 21.1 are formed by an outer steel plate 23 and an inner steel plate 21, creating a sandwich space 22 (wherein, the outer wall of the outer steel plate 23 is covered with a first ceramic fiber cotton insulation layer 23.1, providing excellent insulation). A water tank 12 is installed on one side of the top of the sealed chamber (wherein, the outer wall of the water tank is covered with a second ceramic fiber cotton insulation layer 12.1). An electric heater 15 is installed at the bottom of the water tank 12, and the outlet 17 at the bottom of the water tank 12 is located in the sandwich space 22 of the sealed chamber. Inside the water tank 12, a water pipe 13 is installed at the top, and the other end of the water pipe 13 is connected to a hot water pump 18. A steam extraction pipe 6 (which is also the steam inlet pipe of the steam-water separator 3) is installed on the other side of the top of the sealed chamber 21.1. One end of the steam extraction pipe 6 is inserted into the internal space of the sealed chamber 21.1, and the other end of the steam extraction pipe 6 is connected to the first check valve 4. The first check valve 4 is connected to the humid and hot air inlet 6.1 of the steam-water separator 3. A vacuum gauge 5 is inserted into the steam extraction pipe 6 located in the area near the first check valve 4 (the vacuum gauge 5 displays the vacuum level of the sealed chamber 21.1).

[0035] Vacuum pump 1 is located on the ground. Vacuum pump 1 is connected to the air discharge port 2.1 of the steam-water separator 3 via flange 1.1 and the air outlet pipe 2 (which is also the air inlet pipe of vacuum pump 1) of the steam-water separator 3.

[0036] An air intake steel pipe 9 is installed at the top of the sealed chamber 21.1 near the steam extraction pipe 6. One end of the air intake steel pipe 9 is located inside the sealed chamber 21.1. An electric heating device 10 is installed on the outer wall of the air intake steel pipe 9.

[0037] Install a hot water pump 18 at the other end of water pipe 13.

[0038] Install a water tank control valve 16 at the outlet of water tank 12.

[0039] A drain valve 25 is installed below the steam-water separator 3.

[0040] A second check valve 8 is installed at the air inlet end of the air inlet steel pipe 9.

[0041] A fan 11 is installed on the ceiling inside the sealed chamber 21.1.

[0042] Install controller 24 outside the sealed chamber 21.1.

[0043] The key technology of the above-mentioned method for preventing hardwood products from cracking is as follows:

[0044] 1) Push the steel wheel frame 20, which is loaded with a hardwood pile 19 consisting of about 1200 sheets of hardwood (purchased hardwood finger-jointed boards) (with equal thickness partitions placed between adjacent hardwood boards in the pile), into the sealed chamber 21.1, and then close the steel door 27 tightly (wherein, the core of the steel door is the third ceramic fiber cotton insulation layer 27.1).

[0045] 2) The controller 24 sets the temperature and humidity instruments, fan running time, etc. as follows: the relative humidity of the sealed chamber 21.1 is set to 30% (that is, the average moisture content of the wood in the sealed chamber 21.1 is set to about 6%), so that there is a large wood moisture content gradient between the hardwood in the sealed chamber 21.1 with a moisture content distribution of 6.0% to 11.0% and the average moisture content of the wood in the sealed chamber 21.1; the temperature of the interlayer space 22 is set to 65℃; the fan 11 running (stopping) time is set as follows: the fan 11 starts running when the water tank control valve 16 is opened, and stops running when the hot water pump 18 and vacuum pump 1 are started.

[0046] 3) The controller 24 starts the electric heater 15 to heat the tap water 14 in the water tank 12; when the water temperature is heated to 99℃±1℃, the electric heater 15 stops heating, and when the water temperature is lower than 99℃±1℃, the electric heater 15 starts automatically.

[0047] 4) Controller 24 opens water tank control valve 16, and boiling water at 99℃±1℃ flows into the interlayer space 22. The volume of the interlayer space 22 is slightly larger than the volume of water tank 12. When the boiling water in water tank 12 is emptied, water tank control valve 16 closes automatically.

[0048] 5) During the operation of the fan 11 in the sealed chamber 21.1, the airflow generated transfers the heat of the boiling water stored in the interlayer space 22 to the entire sealed chamber 21.1, and makes the heat and flow rate of the humid air on the surface of each piece of hardwood (purchased hardwood finger-jointed board) in the middle, sides, top, and bottom of the heated sealed chamber space tend to be uniform. At this time, under the simultaneous action of the temperature (heat) gradient and the wood moisture content gradient in the sealed chamber 21.1, the heat-absorbing surface layer and the hardwood core both increase the movement power of water molecules (absorbed water) to varying degrees. In particular, during the process of gas molecules in the humid air in the sealed chamber 21.1 accelerating and effectively colliding with the water molecules on the hardwood surface, the surface layer of the hardwood that has absorbed more heat significantly increases the evaporation (overflow) rate of the hardwood surface moisture (absorbed water) into the sealed chamber 21.1 due to the increased temperature. At this time, the water absorbed by the wood in the hardwood core has a higher wood density, fewer water molecule movement (overflow) paths, and absorbs less heat. The movement of water molecules from the core to the surface of the hardwood is relatively slow. As the heat absorption process continues in both the hardwood core and surface, the temperature of the sealed chamber 21.1 will gradually decrease (the hot water temperature in the interlayer space 22 will also decrease). This change also slows down the evaporation (overflow) of surface moisture (absorbed water) into the sealed chamber 21.1 due to the gradually decreasing temperature, causing the moisture content gradient between the surface and core of the hardwood to decrease. Furthermore, this also hinders the surface hardening (internal cracking, etc.) of the hardwood.

[0049] When the temperature sensor 7.1 detects that the water temperature in the interlayer space 22 has dropped to 65℃±2℃, the controller 24 starts the hot water pump 18 and simultaneously opens the first check valve 4 to run the vacuum pump 1.

[0050] When the hot water pump 18 is running, it pumps all the hot water stored in the interlayer space 22 back to the water tank 12 through the water pipe 13 to continue heating to 99℃±1℃;

[0051] 6) During the operation of vacuum pump 1, vacuum pump 1 extracts the humid and hot air from the sealed chamber 21.1 through the extraction pipe 6, the first check valve 4, the steam-water separator 3, and the outlet pipe 2 of the steam-water separator 3 (which is also the inlet pipe of vacuum pump 1), and puts the sealed chamber 21.1 into a vacuum (negative pressure) state (the vacuum degree is kept stable at 0.04MPa for 60 minutes); the exhaust end of vacuum pump 1 discharges the air extracted from the sealed chamber 21.1 through the extraction pipe 6, the first check valve 4, the steam-water separator 3, and the outlet pipe 2 of the steam-water separator 3 (which is also the inlet pipe of vacuum pump 1) to the outdoor space;

[0052] The vapor-water separator 3 condenses water vapor from the humid and hot air in the sealed chamber 21.1 into liquid water through its internal vapor condensation system (the water vapor mainly comes from evaporation into the sealed chamber 21.1, water adsorbed in the hardwood fiber tissue, and harmful compound solvents remaining in the hardwood fiber tissue); when the vacuum pump runs for 60 minutes, the controller 24 shuts off the vacuum pump 1 and the first check valve 4, and opens the drain valve 25 to drain the liquid water in the vapor-water separator 3 into the ground ditch 26;

[0053] During the operation of the vacuum pump, the hot water stored in the interlayer space 22 is completely extracted, causing the temperature of the entire sealed chamber 21.1 to be in a vacuum (negative pressure) state, which further decreases (further changes towards the outdoor normal temperature). This further change makes the process of the surface moisture (absorbed water) of the hardwood evaporating (overflowing) into the sealed chamber 21.1 more slow due to the further decrease in the indoor temperature (further reduction in the heat absorbed by the hardwood).

[0054] The vacuum (negative pressure) state, on the one hand, causes the core moisture (absorbed water) and harmful compound solvents remaining in the hardwood fiber tissue of the hardwood placed in the sealed 21.1 space to move rapidly to the surface of the hardwood due to the decrease in the air pressure around the hardwood. On the other hand, it also significantly reduces the probability of water molecules on the surface of the hardwood colliding effectively with the humid and hot gas molecules in the sealed 21.1 space due to the thin air in the sealed 21.1 space, thereby further slowing down the evaporation (overflow) process of the surface moisture (absorbed water) of the hardwood into the sealed 21.1 space.

[0055] In summary, the slowing down of the evaporation (overflow) process of surface moisture (absorbed water) in the hardwood to the sealed 21.1 space, and the rapid acceleration of the movement of moisture (absorbed water) in the hardwood core and harmful compound solvents remaining in the hardwood fiber tissue to the hardwood surface, significantly reduce the moisture content gradient between the surface and core of the hardwood during the post-forming process (hardwood material stability optimization process), and significantly reduce the stress between the surface and core of the hardwood. This effectively prevents the occurrence of surface hardening (internal cracking, etc.) quality problems in hardwood during the post-forming process in the "intermittent heating-vacuum (negative pressure)" technology system of this invention.

[0056] 7) Controller 24 opens the second check valve 8 and the electric heating device 10. The electric heating device 10 heats and dehumidifies the external humid air at normal pressure as it passes through the intake steel pipe 9, turning it into dry air that enters the sealed chamber 21.1, which is under negative pressure (vacuum degree = 0.04MPa). (After the dry air enters, the sealed chamber 21.1 returns to normal pressure). When the vacuum gauge 5 reading reaches the outdoor normal pressure (≈1.0Kg / cm³), 2(That is, when the sealed chamber 21.1 reaches the outdoor atmospheric pressure state) the controller closes the second check valve 8 and the electric heating device 10;

[0057] 8) The controller 24 opens the water tank control valve 16 to allow boiling water at 99℃±1℃ to flow back into the interlayer space 22), and starts the running fan 11, thus entering the next cycle;

[0058] Boiling water at 99℃±1℃ flows into the interlayer space 22 (the sealed interior space 21.1 is under heating and atmospheric pressure). When the water temperature in the interlayer space 22 drops to 65℃±2℃, the controller 24 starts the hot water pump 18 and simultaneously opens the first check valve 4 and runs the vacuum pump 1 (the entire sealed interior space 21.1 is under cooling and negative pressure). The vacuum pump stops running when the set time limit of 60 minutes is reached. The controller 24 opens the second check valve 8 and the electric heating device 10. The electric heating device 10 heats and dehumidifies the external humid air under atmospheric pressure as it passes through the air inlet steel pipe 9, turning it into dry air that enters the sealed interior space 21.1 under negative pressure (vacuum degree = 0.04MPa) (the dry air restores the sealed interior space 21.1 to atmospheric pressure). The water tank control valve 16 is opened, allowing the boiling water at 99℃±1℃ to flow back into the interlayer space 22 (the entire sealed interior space 21.1 is again under heating and atmospheric pressure).

[0059] The above process constitutes the "intermittent heating-vacuum (negative pressure)" operation state of the sealed chamber 21.1;

[0060] 9) In summary, after several cycles of "intermittent heating-vacuum (negative pressure)" operation (the entire process lasts 3-4 days), when the controller 24 receives data (signals) from the four probes 7 located on the roof of the sealed chamber 21.1, all showing that the average moisture content of the wood in the sealed chamber 21.1 has been consistently stable within the range of 30% ± 2% (at this time, the moisture content of the hardwood in the sealed chamber 21.1 has been stable within the range of 6.0% ± 1.0%), the entire system of this invention will end operation. The system power will be turned off, the steel door 27 will be opened, and the steel wheeled vehicle 20 carrying the hardwood stack 19 will be moved out of the sealed chamber 21.1.

Claims

1. A device for hard wood cracking of a frictional solid wood product, having a closed chamber (21.1), characterized in that The walls of the sealed chamber (21.1) are formed by an outer steel plate (23) and an inner steel plate (21) creating a mezzanine space (22). A water tank (12) is installed on one side of the top of the sealed chamber. An electric heater (15) is installed at the bottom of the water tank (12). The outlet (17) of the water tank (12) is located within the mezzanine space (22) of the sealed chamber. A water pipe (13) is installed at the top of the water tank (12), and the other end of the water pipe (13) is connected to a hot water pump (18). On the other side, a steam extraction pipe (6) is installed. One end of the steam extraction pipe (6) is inserted into the internal space of the sealed chamber (21.1), and the other end is connected to the steam-water separation device (3). The steam-water separation device (3) is connected to the vacuum pump (1) through the exhaust pipe (2). An air inlet steel pipe (9) is installed at the top of the sealed chamber (21.1) near the steam extraction pipe (6). One end of the air inlet steel pipe (9) is located inside the sealed chamber (21.1), and an electric heating device (10) is installed on the outer wall of the air inlet steel pipe (9).

2. The device for hard wood cracking of the hysteresis solid wood product according to claim 1, characterized in that Install a hot water pump (18) at the other end of the water pipe (13).

3. The device for hard wood cracking of the lagging solid wood product according to claim 1, characterized in that Install a water tank control valve (16) at the outlet of the water tank (12).

4. The device for preventing hardwood cracking in solid wood products according to claim 1, characterized in that: A drain valve (25) is installed below the steam-water separator (3).

5. The device for preventing hardwood cracking in solid wood products according to claim 1, characterized in that: Install a second check valve (8) on the intake steel pipe (9).

6. The device for preventing hardwood cracking in solid wood products according to claim 1, characterized in that: A fan (11) is installed on the ceiling inside the sealed chamber (21.1).

7. The device for preventing hardwood cracking in solid wood products according to claim 1, characterized in that: A controller (24) is installed outside the sealed chamber (21.1).

8. The device for preventing hardwood cracking in solid wood products according to claim 1, characterized in that: The outer wall of the outer steel plate (23) is covered with a first ceramic fiber cotton insulation layer (23.1), and the outer wall of the water tank (12) is covered with a second ceramic fiber cotton insulation layer (12.1).

9. The method for preventing hardwood cracking in solid wood products as described in claim 1, characterized in that... The method is as follows: 1) Push the hardwood pile (19) into the sealed chamber (21.1) and then close the steel door (27). 2) The controller (24) sets the operating time of the temperature and humidity instruments and the fan; 3) The controller (24) starts the electric heater (15) to heat the tap water (14) in the water tank (12); 4) The controller (24) opens the water tank control valve (16), and boiling water flows into the interlayer space (22); when the water temperature in the interlayer space (22) drops to 65℃±2℃, the controller (24) starts the hot water pump (18) and makes the vacuum pump (1) run; when the hot water pump (18) runs, it draws all the hot water stored in the interlayer space (22) back to the water tank (12) through the water pipe (13) to continue heating it into boiling water; 5) The fan (11) operates to transfer and balance the heat in the sealed chamber (21.1); 6) When the vacuum pump (1) is running, it extracts the hot and humid air in the sealed chamber (21.1) through the steam extraction pipe (6), and the steam-water separation device (3) condenses the water vapor in the hot and humid air into liquid water and discharges it. 7) The controller (24) opens the second check valve (8) and the electric heating device (10). When the external humid and hot air under normal pressure passes through the air inlet steel pipe (9), it is heated and dehumidified and becomes dry air, which enters the sealed chamber (21.1) space under negative pressure. 8) The controller (24) opens the water tank control valve (16) to allow boiling water to flow back into the interlayer space (22) and enter the next cycle; 9) After several cycles, when the average moisture content of the wood in the sealed chamber (21.1) has been consistently stable within the range of 30%±2%, the entire system operation ends and the hardwood pile (19) is removed from the sealed chamber (21.1).

10. The method for preventing hardwood cracking in solid wood products according to claim 9, characterized in that steel... The core of the door (27) is a third ceramic fiber cotton insulation layer (27.1).

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