阅读说明：本技术 一种连续式木材改性热处理工艺及系统 (Continuous wood modification heat treatment process and system ) 是由 周明武 王雄 于 2019-11-27 设计创作，主要内容包括：本发明提供了一种连续式木材改性热处理工艺,将初始木材胚料相互间隔堆放于台车上,顶部施加压力使初始木材胚料各处受力均衡保持平整,依次经过以下处理步骤：预热处理、升温处理、干燥处理、炭化处理、缓冷处理、快冷处理和回湿处理,每个处理步骤中包括多个窑炉,S2-S4步骤中窑炉之间等梯度升温设置,S5-S7步骤中窑炉之间等梯度降温设置；本发明提供了一种连续式木材改性热处理的系统,连续式木材热处理的系统包括多个窑炉、台车和驱动台车移动的传动装置；微波与其它热源加热装置。本发明的工艺及系统,提供了一种能耗低,生产周期短,木材的内部与表面炭化程度均匀一致,强度高,性能稳定的高品质木材,且生产成本低,适于大批量生产。(The invention provides a continuous wood modification heat treatment process, which is characterized in that initial wood blanks are stacked on a trolley at intervals, pressure is applied to the top of the trolley to enable the stress of each part of the initial wood blanks to be balanced and kept flat, and the continuous wood modification heat treatment process sequentially comprises the following processing steps: preheating treatment, heating treatment, drying treatment, carbonization treatment, slow cooling treatment, fast cooling treatment and rewetting treatment, wherein each treatment step comprises a plurality of kilns, the kilns in the steps S2-S4 are subjected to equal gradient heating setting, and the kilns in the steps S5-S7 are subjected to equal gradient cooling setting; the invention provides a continuous wood modification heat treatment system, which comprises a plurality of kilns, trolleys and a transmission device for driving the trolleys to move; microwave and other heat sources. The process and the system provided by the invention provide the high-quality wood which has the advantages of low energy consumption, short production period, uniform and consistent carbonization degree of the interior and the surface of the wood, high strength and stable performance, and is low in production cost and suitable for mass production.)

1. A continuous wood modification heat treatment process is characterized in that initial wood blanks are stacked on a trolley at intervals, pressure is applied to the top of the trolley to enable the blanks to be stressed evenly and kept flat, and the continuous wood modification heat treatment process sequentially comprises the following processing steps:

s1, preheating: moving the trolley loaded with the initial wood blank into a preheating kiln, wherein the preheating treatment temperature is 30-50 ℃;

s2, temperature rising treatment: transferring the initial wood blank processed by the S1 into a heating kiln, wherein the flow rate of water vapor is 2-5 cubic/hour, the temperature of heating treatment is 60-100 ℃, and the humidity range is 50-100%;

s3, drying: the drying treatment comprises two steps, wherein in the first step, the initial wood blank treated by S1 is moved into a shallow drying kiln, the drying treatment temperature is 100-120 ℃, in the second step, the initial wood blank treated in the first step is moved into a deep drying kiln, the drying treatment temperature is 120-120 ℃, the oxygen content range of the drying treatment is 1-10%, the water vapor flow is 1-10 cubic/hour, and microwave and hot air circulation combined heating is adopted;

s4, carbonization treatment: transferring the initial wood blank treated by the S3 into a carbonization kiln, wherein the carbonization treatment temperature is 120 ℃ and 180 ℃, the oxygen content range is 1-5%, and the initial wood blank is subjected to microwave and hot air circulation combined heating;

s5, slow cooling treatment: transferring the initial wood blank processed by the S4 to a slow cooling kiln, wherein the slow cooling processing temperature is 120 ℃ and 130 ℃, and the oxygen content range is 1-10%;

s6, quick cooling treatment: transferring the initial wood blank processed by the S5 to a quick cooling kiln, wherein the quick cooling processing temperature is 90-100 ℃;

s7, rewetting treatment: transferring the initial wood blank processed by the S6 to a moisture-returning kiln, wherein the humidity range is 50-100%, and the initial wood blank is taken out of the kiln when the temperature is 40-60 ℃ and the water content is 6-10%;

each processing step comprises a plurality of kilns, wherein the kilns in the steps S2-S4 are subjected to equal gradient temperature rise setting, and the kilns in the steps S5-S7 are subjected to equal gradient temperature reduction setting; the time for processing the initial wood blank by each kiln is more than 0 and less than 2 hours, and circulating air is introduced into the kilns; the moisture regaining kiln is internally provided with water vapor for providing wood moisture regaining.

2. The continuous wood modification heat treatment process according to claim 1, wherein in the same treatment step, the temperature difference between the kilns is less than or equal to 20 ℃; the initial wood blank is pre-dried to the water content of 10% -30% before entering a kiln; the steam flow rate in the working process of the S2, S3 and S4 is 1-10m³/h。

3. A continuous wood modification heat treatment system according to any one of claims 1-2, characterized in that the continuous wood heat treatment system comprises a plurality of kilns, trolleys (19.6) and transmission means for driving the trolleys (19.6) to move at the bottom of the kilns;

the upper part of the trolley (19.6) is provided with initial wood blanks which are stacked at intervals and a pressing device which enables the initial wood blanks to be stressed evenly;

the multiple kilns are sequentially connected in series along the advancing direction of the trolley (19.6), the end parts of the kilns are provided with furnace doors (20.5), and the multiple kilns comprise a preheating kiln (I), a heating kiln (II), a drying kiln (III), a carbonization kiln (IV), a slow cooling kiln (V), a fast cooling kiln (VI) and a rewetting kiln (VII);

a fan (2), a partition plate (6), a shunt cover (3) and an exhaust port (1) are arranged in the kiln;

the kiln wall is equipped with outside gas vent (1) of intercommunication, and baffle (6) divide into upper strata and lower floor workspace with kiln inside, and upper strata is located in reposition of redundant personnel cover (3), and fan (2) forms the return circuit with lower floor workspace, reposition of redundant personnel cover (3) intercommunication in proper order.

4. A continuous wood modification heat treatment system according to claim 3, characterized in that the lower working area of the kiln is further provided with a splitter plate (4), and the splitter plate (4) is arranged on the wall of the kiln parallel to the advancing direction of the trolley (19.6); sieve pores are arranged on the symmetrically arranged splitter plates (4), and the sieve pores on the air inlet side are distributed gradually and densely from top to bottom; the sieve pores on the gas receiving side are gradually distributed from top to bottom; one end of the splitter plate (4) is connected with the clapboard (6), and the other end is connected with the bottom of the kiln.

5. The continuous wood modification and heat treatment system according to claim 3, wherein the temperature rising kiln, the drying kiln and the carbonization kiln are provided with microwave sources, each microwave source comprises a microwave power supply (11), a microwave magnetron (10) and a microwave slot antenna (9), the microwave power supplies (11) are electrically connected with the microwave magnetrons (10), the microwave magnetrons (10) are connected with the microwave slot antennas (9) vertically arranged in the lower working area, the microwave slot antennas (9) are uniformly distributed and arranged on the inner sides of the two splitter plates (4) along the moving direction of the trolley, the microwave slot antennas (9) are provided with microwave radiation holes (9.1) facing the wood blank, and the microwave radiation holes (9.1) are staggered and arranged in the vertical direction.

6. A continuous wood modification heat treatment system according to claim 3, wherein the temperature-raising kiln, the drying kiln, the carbonization kiln and the rapid cooling kiln are provided with steam nozzles (7) communicated with a steam source; the temperature rising kiln, the drying kiln and the carbonization kiln are provided with heat exchangers (15), the quick cooling kiln is internally provided with a refrigerator, and the heat exchangers (15) and the refrigerator sequentially form a loop with the fan (2), the flow dividing cover (3) and the lower working area.

7. A continuous wood modification heat treatment system as claimed in claim 3, wherein the rewetting kiln is provided with a nozzle (17) communicating with a water source.

8. A continuous wood modification heat treatment system according to claim 3, wherein the transmission comprises a gear (16), a driving motor (5) and a rack (18) cooperating with the gear (16); the rack (18) is arranged at the bottom of the trolley (19.6), and the bottom of each kiln is provided with a gear (16) in transmission connection with an output shaft of a driving motor (5) outside the kiln.

9. A continuous wood modification heat treatment system according to claim 3, wherein the hold-down device comprises a batten (19.1), a cable (19.2), an elastic member (19.4), a rope puller (19.5); the initial wood blanks are stacked at intervals through parting strips (19.3), and the pressing strips (19.1) are arranged at the positions corresponding to the parting strips (19.3); the pressing devices are symmetrically arranged on two sides of the trolley (19.6) in the advancing direction of the trolley (19.6) at equal intervals, the rope pulling device (19.5) is arranged on the trolley, one end of the cable (19.2) is connected to the rope pulling device (19.5), the other end of the cable is connected to the pressing strip (19.1), and the elastic piece (19.4) is arranged in the cable (19.2).

10. The continuous wood modification heat treatment system according to claim 3, wherein a furnace door cavity is arranged between the furnace and the kiln, a winding drum mechanism is arranged at the upper part in the furnace door cavity, the winding drum mechanism comprises a winding drum (20.2) and a pull rope (20.3), a rotating shaft (20.1) connected with an output shaft of a motor is arranged in the winding drum, one end of the pull rope (20.3) is wound on the winding drum (20.2), and the other end is connected with the furnace door (20.5).

Technical Field

The invention relates to the technical field of wood processing, in particular to a continuous wood modification heat treatment process and system.

Background

The wood material is natural, and is deeply favored by people due to natural texture and beautiful color. Due to the biological properties and various characteristics of wood, the wood is easy to dry, shrink and swell under the change of external damp and hot conditions, is a material with unstable size, and the property has adverse effect on the utilization of the wood. The inside moisture content of timber from trees felling is great, if directly make it into panel, then in follow-up use easily because panel is heated the back can lead to the inside moisture evaporation of panel to lead to the condition of sunken or fracture to appear in the panel, or adopt the panel that fresh timber directly made can lead to the cell wall in the panel to absorb water behind the chance water thereby expand, will lead to the condition that panel appears protrusion or inflation like this, no matter sunken or protrusion can lead to the final normal use who influences panel of panel unevenness, consequently in order to overcome this problem, generally all can carry out heat treatment or carbomorphism to timber after timber is felled from trees at present.

However, the existing wood heat treatment technology is mainly to place the wood into a large-scale hot kiln, which belongs to intermittent operation, and the wood is heated unevenly and carbonized in the heat treatment process, so that local coking, bulging, deformation, cracking and the like are easily caused. In addition, the existing heat kiln treatment adopts a method of gradually increasing the temperature, so that the heat treatment energy consumption is high, the production period is long, the problem of wood bending strength loss caused by a wood-free heat treatment process is easily caused, and the subsequent use of the wood cannot meet the requirements.

Disclosure of Invention

The invention aims to provide a continuous wood modification heat treatment process and a continuous wood modification heat treatment system, which overcome the defects of the traditional heat treatment of wood, and provide high-quality wood with low energy consumption, short production period, uniform and consistent carbonization degree of the interior and the surface of the wood, good mechanical properties such as bending strength, impact toughness, nail holding force and the like, stable performance, low production cost and contribution to mass production.

In order to realize the purpose, the invention adopts the technical scheme that:

a continuous wood modification heat treatment process is characterized in that initial wood blanks are stacked on a trolley at intervals, pressure is applied to the top of the trolley to enable the blanks to be stressed evenly and kept flat, and the continuous wood modification heat treatment process sequentially comprises the following processing steps:

s1, preheating: moving the trolley loaded with the initial wood blank into a preheating kiln, wherein the preheating treatment temperature is 30-50 ℃;

s2, temperature rising treatment: transferring the initial wood blank processed by the S1 into a heating kiln, wherein the steam flow is 2-5 cubic/hour during working, and the heating processing temperature is 60-100 ℃;

s3, drying: the drying treatment comprises two steps, wherein in the first step, the initial wood blank treated by S1 is moved into a shallow drying kiln, the drying treatment temperature is 100-120 ℃, in the second step, the initial wood blank treated in the first step is moved into a deep drying kiln, the drying treatment temperature is 120-120 ℃, the oxygen content range of the drying treatment is 1-10%, the water vapor flow is 1-10 cubic/hour, and microwave and hot air circulation combined heating is adopted;

s4, carbonization treatment: transferring the initial wood blank treated by the S3 into a carbonization kiln, wherein the carbonization treatment temperature is 120 ℃ and 180 ℃, the oxygen content range is 1-5%, and the initial wood blank is subjected to microwave and hot air circulation combined heating;

s5, slow cooling treatment: transferring the initial wood blank processed by the S4 to a slow cooling kiln, wherein the slow cooling processing temperature is 120 ℃ and 130 ℃, and the oxygen content range is 1-10%;

s6, quick cooling treatment: transferring the initial wood blank processed by the S5 to a quick cooling kiln, wherein the quick cooling processing temperature is 90-100 ℃;

s7, rewetting treatment: transferring the initial wood blank processed by the S6 to a moisture-returning kiln, wherein the humidity range is 50-100%, and the initial wood blank is taken out of the kiln when the temperature is 40-60 ℃ and the water content is 6-10%;

each processing step comprises a plurality of kilns, wherein the kilns in the steps S2-S4 are subjected to equal gradient temperature rise setting, and the kilns in the steps S5-S7 are subjected to equal gradient temperature reduction setting; the time for processing the initial wood blank by each kiln is more than 0 and less than 2 hours, and circulating air is introduced into the kilns; the moisture for providing wood moisture regaining is arranged in the moisture regaining kiln.

Further, in the same treatment step, the temperature difference range between the kilns is less than or equal to 20 ℃; the initial wood blank is dried in advance before entering a kilnThe water content is 10-30%; the steam flow rate in the working process of the S2, S3 and S4 is 1-10m³/h。

A continuous wood modification heat treatment system comprises a plurality of kilns, trolleys and a transmission device for driving the trolleys to move at the bottoms of the kilns;

the upper part of the trolley is provided with initial wood blanks which are stacked at intervals and a pressing device which enables the initial wood blanks to be stressed evenly;

the multiple kilns are sequentially connected in series along the advancing direction of the trolley, the end parts of the kilns are provided with furnace doors, and the multiple kilns comprise a preheating kiln (I), a heating kiln (II), a drying kiln (III), a carbonization kiln (IV), a slow cooling kiln (V), a fast cooling kiln (VI) and a rewetting kiln (VII);

a fan, a partition plate, a flow dividing cover and an exhaust port are arranged in the kiln; the kiln wall is provided with an exhaust port communicated with the outside, the inside of the kiln is divided into an upper working area and a lower working area by a partition plate, a shunting cover is arranged on the upper layer, and a fan is sequentially communicated with the lower working area and the shunting cover to form a loop;

furthermore, a flow distribution plate is arranged in the lower working area of the kiln and is arranged on the kiln wall parallel to the advancing direction of the trolley; sieve pores are arranged on the symmetrically arranged splitter plates, and the sieve pores on the air inlet side are distributed gradually and densely from top to bottom; the sieve pores on the gas receiving side are gradually distributed from top to bottom; one end of the splitter plate is connected with the partition plate, and the other end of the splitter plate is connected with the bottom of the kiln;

furthermore, the heating kiln, the drying kiln and the carbonization kiln are provided with microwave sources, the microwave sources comprise microwave power supplies, magnetrons and microwave slot antennas, the microwave power supplies are electrically connected with the magnetrons, the magnetrons are connected with the microwave slot antennas vertically arranged in a lower working area, the microwave slot antennas are uniformly distributed and arranged on the inner sides of the two splitter plates along the moving direction of the trolley, the microwave slot antennas are provided with microwave radiation holes facing the wood blank, and the microwave radiation holes are staggered in the vertical direction.

Further, steam spray pipes communicated with a steam source are arranged in the heating kiln, the drying kiln, the carbonization kiln and the quick cooling kiln; the temperature rising kiln, the drying kiln and the carbonization kiln are provided with heat exchangers, the quick cooling kiln is internally provided with a refrigerator, and the heat exchangers and the refrigerator sequentially form a loop with the fan, the flow dividing cover and the lower working area.

Furthermore, a spray pipe communicated with a water source is arranged in the rewetting kiln.

Further, the transmission device comprises a gear, a driving motor and a rack matched with the gear; the rack is arranged at the bottom of the trolley, and a gear in transmission connection with an output shaft of a driving motor outside the kiln is arranged at the bottom of each kiln.

Furthermore, the pressing device comprises a pressing strip, a cable, an elastic piece and a rope pulling device; stacking the initial wood blanks at intervals through parting strips, wherein the parting strips are arranged at the positions corresponding to the parting strips; the pressing devices are symmetrically arranged on two sides of the trolley in the advancing direction of the trolley at equal intervals, the rope pulling device is arranged on the trolley, one end of the cable is connected to the rope pulling device, the other end of the cable is connected to the pressing strip, and the elastic piece is arranged in the cable.

Furthermore, the end part of the kiln is provided with a kiln door cavity, the upper part in the kiln door cavity is provided with a winding drum mechanism, the winding drum mechanism comprises a winding drum and a pull rope, an output shaft of the motor is connected with a rotating shaft in the winding drum, one end of the pull rope is wound on the winding drum, and the other end of the pull rope is connected with the kiln door.

The invention has the beneficial effects that:

1. the invention reduces the defects of cracking, deformation and the like of the initial wood blank due to internal stress and uneven water content by the early temperature treatment of airing, preheating and heating treatment of the initial wood blank, and improves the qualification rate of the initial wood blank.

2. When the initial wood blank is processed, after all kilns reach the set parameter conditions of temperature, humidity and the like, the initial wood blank continuously enters the adjacent kilns from the preheating kiln, the carbonization treatment in the kilns is more than 0 and less than 2H until the kiln leaves the rewetting kiln, the temperature in the kiln keeps constant at the preset temperature, the initial wood blank can be continuously processed in a large batch, and compared with the timed heating and cooling operation of each batch of materials in the traditional processing, the energy consumption is saved by more than half; the traditional conventional production period is 5 days, and the production period is 15-35 hours by adopting the multi-kiln continuous process, so that the production period is greatly shortened, and the economic benefit is improved.

3. When the initial wood blank is treated, the temperature in the kiln reaches a constant value, and then the initial wood blank to be treated is added, so that the wood is heated uniformly; in addition, microwave treatment is simultaneously used from two sides, so that the phenomena that the energy received by the initial wood blank on the left side and the right side is uneven and the energy received by the outer surface and the inner part of the wood is uneven in the traditional treatment from one side are solved; the microwave slot antennas are arranged at equal intervals in the advancing direction of the trolley, the microwave radiation holes are arranged in a staggered mode in the vertical direction, and the staggered arrangement meets the distribution of the radiation microwave energy intensity of the microwave radiation holes, so that the energy received by the initial wood blank at different positions, the interior of the initial wood blank and the surface of the initial wood blank are balanced; the sieve holes on the air inlet side in the flow distribution plate are distributed gradually and densely from top to bottom; the sieve pores on the splitter plate at the gas collecting side are gradually and sparsely distributed from top to bottom; the problem that the time intervals for maintaining the fixed temperatures of upper and lower initial wood blanks are the same is solved, and the traditional ventilation causes different time intervals for maintaining the fixed temperatures of the upper and lower initial wood blanks due to the fact that the temperature of upper sieve holes is high, the gas strength is high, the inflow speed is high, the temperature of lower sieve holes is low, the gas strength is low, and the inflow speed of the upper and lower initial wood blanks is low, so that the upper and lower initial wood blanks are heated unevenly at the same time interval, and cracks and bubbles do not occur; and the inner diameter of the sieve pore of the flow distribution plate is 1-5mm, which is beneficial to maintaining the effect of microwave radiation heating of the microwave radiation hole on the initial wood blank.

4. The movable door of the kiln is driven by the motor, so that the structure is simple, the working resistance is small, the service life is long, and by adopting the mode, a single person can easily open or close the kiln door, the labor cost is saved, and the trolley can conveniently go in and out and move; the pressing device of the invention ensures that the pressure of the wood is uniformly received in the carbonization process, the wood is not curled or expanded, and the whole stretching effect of the carbonized initial wood blank is good.

5. The heating kiln, the drying kiln and the carbonization kiln can effectively maintain the preset temperature under the action of water molecules in a saturated water vapor environment, shorten the time of heat treatment and reduce the energy consumption; the degradation of the nutrients in the initial wood blank is more thorough; the treated wood has more uniform color, can avoid the cracking of the wood in the heat treatment process, and effectively improves the quality of the heat-treated wood.

6. The modified heat treatment process takes oak wood as a processing object, and after the processing, the water content of the carbonized wood is 5-10%; the heat shrinkage resistance of wood is: the length direction is less than or equal to 0.2 percent, and the width direction is less than or equal to 1.5 percent; resistance to Wet swelling: the length direction is less than or equal to 0.2 percent, and the width direction is less than or equal to 0.8 percent; the surface has no cracks and no bubbling phenomenon; the conventional total process has the advantages that the strength is uniform, the static bending strength is more than or equal to 50MPa along the grain direction, the static bending strength transverse grain direction is more than or equal to 45MPa, the elastic modulus is more than or equal to 5000MPa along the grain direction, and the elastic modulus transverse grain direction is more than or equal to 4000 MPa.

Drawings

FIG. 1 is a schematic view of a system layout for continuous wood carbonization treatment according to the present invention;

FIG. 2 is a schematic view of a sectional structure A-A of the preheating kiln of the present invention;

FIG. 3 is a schematic structural view of a section B-B of the heating kiln, the drying kiln and the carbonization kiln of the present invention;

FIG. 4 is a schematic view of a slow cooling kiln of the present invention;

FIG. 5 is a schematic view of the cross-sectional structure of the fast cooling kiln C-C of the present invention;

FIG. 6 is a schematic view of a D-D cross-sectional structure of the rewetting kiln of the present invention;

FIG. 7 is a front view of an intake side manifold of the present invention;

FIG. 8 is a schematic diagram of a microwave slot antenna structure according to the present invention;

FIG. 9 is a side view of the trolley of the present invention;

FIG. 10 is a front view of the trolley of the present invention;

FIG. 11 is the first page of a detection report for a carbonized oak wood floor stock in example 1 of the present invention;

FIG. 12 is a second page of a detection report for the carbonized oak wood floor stock of example 1;

FIG. 13 is the third page of the detection report for the carbonized oak wood floor stock in example 1 of the present invention;

fig. 14 is the fourth page of the detection report of the oak wood floor blank after carbonization treatment in example 1 of the present invention.

The text labels in the figures are represented as: 1. an exhaust port; 2. a fan; 3. a flow dividing cover; 4. a flow distribution plate; 5. a drive motor; 6. a partition plate; 7. a steam nozzle; 8. a radiant tube; 9. a microwave slot antenna; 9.1, microwave radiation holes; 10. a microwave magnetron; 11. a microwave power supply; 12. a microwave source adapter; 13. the partition plate is opened; 14. a second separator; 15. a heat exchanger; 16. a gear; 17. a nozzle; 18. a rack; 19.1, pressing strips; 19.2, cables; 19.3, parting beads; 19.4, an elastic piece; 19.5, rope drawing device; 19.6, a trolley; 19.7, rolling wheels; 20.1, a rotating shaft; 20.2, winding drum; 20.3, pulling a rope; 20.4, a heat insulation plate; 20.5 and a furnace door.

Detailed Description

The present invention is described in detail below for the purpose of better understanding technical solutions of the present invention by those skilled in the art, and the description of the present invention is only exemplary and explanatory and should not be construed as limiting the scope of the present invention in any way.

A continuous wood modification heat treatment process is characterized in that initial wood blanks are stacked on a trolley at intervals, pressure is applied to the top of the trolley to enable the blanks to be stressed evenly and kept flat, and the continuous wood modification heat treatment process sequentially comprises the following processing steps:

s1, preheating: moving the trolley loaded with the initial wood blank into a preheating kiln, wherein the preheating treatment temperature is 30-50 ℃;

s2, temperature rising treatment: transferring the initial wood blank processed by the S1 into a heating kiln, wherein the flow rate of water vapor is 2-5 cubic/hour, the temperature of heating treatment is 60-100 ℃, and the humidity range is 50-100%;

s3, drying: the drying treatment comprises two steps, wherein in the first step, the initial wood blank treated by S1 is moved into a shallow drying kiln, the drying treatment temperature is 100-120 ℃, in the second step, the initial wood blank treated in the first step is moved into a deep drying kiln, the drying treatment temperature is 120-120 ℃, the oxygen content range of the drying treatment is 1-10%, the water vapor flow is 1-10 cubic/hour, and microwave and hot air circulation combined heating is adopted;

s4, carbonization treatment: transferring the initial wood blank treated by the S3 into a carbonization kiln, wherein the carbonization treatment temperature is 120 ℃ and 180 ℃, the oxygen content range is 1-5%, and the initial wood blank is subjected to microwave and hot air circulation combined heating;

s5, slow cooling treatment: transferring the initial wood blank processed by the S4 to a slow cooling kiln, wherein the slow cooling processing temperature is 120 ℃ and 130 ℃, and the oxygen content range is 1-10%;

s6, quick cooling treatment: transferring the initial wood blank processed by the S5 to a quick cooling kiln, wherein the quick cooling processing temperature is 90-100 ℃;

s7, rewetting treatment: transferring the initial wood blank processed by the S6 to a moisture-returning kiln, wherein the humidity range is 50-100%, and the initial wood blank is taken out of the kiln when the temperature is 40-60 ℃ and the water content is 6-10%;

each processing step comprises a plurality of kilns, wherein the kilns in the steps S2-S4 are subjected to equal gradient temperature rise setting, and the kilns in the steps S5-S7 are subjected to equal gradient temperature reduction setting; the time for processing the initial wood blank by each kiln is more than 0 and less than 2 hours, and circulating air is introduced into the kilns; the moisture for providing wood moisture regaining is arranged in the moisture regaining kiln.

Preferably, in the same treatment step, the temperature difference range between the kilns is less than or equal to 20 ℃; the initial wood blank is pre-dried to the water content of 10% -30% before entering a kiln; the steam flow rate in the working process of the S2, S3 and S4 is 1-10m 3/h.

When the kiln does not work, the water vapor flow of S2, S3 and S4 is 0-2m3/h, and the water vapor in the kiln is gradually stopped from being introduced.

As shown in fig. 1, a continuous wood modification heat treatment system comprises a plurality of kilns, a trolley 19.6 and a transmission device for driving the trolley 19.6 to move at the bottom of the kiln;

the upper part of the trolley 19.6 is provided with initial wood blanks which are stacked at intervals and a pressing device which enables the initial wood blanks to be stressed evenly; the multiple kilns are sequentially connected in series along the advancing direction of the trolley 19.6, the end parts of the kilns are provided with furnace doors 20.5, and the multiple kilns comprise a preheating kiln I, a heating kiln II, a drying kiln III, a carbonization kiln IV, a slow cooling kiln V, a fast cooling kiln VI and a rewetting kiln VII;

as shown in fig. 2-6, a fan 2, a partition plate 6, a flow dividing cover 3 and an exhaust port 1 are arranged in the kiln; the kiln wall is provided with an exhaust port 1 communicated with the outside, the inside of the kiln is divided into an upper working area and a lower working area by a partition plate 6, a shunting cover 3 is arranged on the upper layer, and a fan 2 is sequentially communicated with the lower working area and the shunting cover 3 to form a loop;

preferably, the trolley 19.6 comprises a trolley frame and rolling wheels 19.7, and at least 2 groups of rolling wheels 19.7 are arranged at the bottom of the trolley frame; the upper part of the trolley frame is provided with initial wood blanks which are arranged at intervals by using partition strips 19.3, and the top part of the trolley frame is provided with a pressing strip 19.1.

Preferably, the fan 2 is arranged at the top of the inner wall of the kiln, the partition plate 6 is arranged at an interval with the fan 2, the lower part of the fan 2 is provided with a flow distribution cover 3 matched with the fan 2, one end of the flow distribution cover 3 is connected with the end part of the fan 2, and the other end of the flow distribution cover is connected with the partition plate 6; the splitter plate 4 is arranged in parallel on the side wall of the kiln which is vertical to the advancing direction of the trolley 19.6.

As shown in fig. 7, the lower working area of the kiln is also provided with a splitter plate 4, and the splitter plate 4 is arranged on the wall of the kiln parallel to the advancing direction of the trolley 19.6; the symmetrically arranged splitter plates 4 are provided with sieve pores, and the sieve pores on the air inlet side are distributed gradually and densely from top to bottom; the sieve pores on the gas receiving side are gradually distributed from top to bottom; one end of the splitter plate 4 is connected with the clapboard 6, and the other end is connected with the bottom of the kiln.

Preferably, the spacer 6 has a horizontal area larger than the area of the initial wood blank on the trolley 19.6 and covers the horizontal surface of the initial wood blank from the vertical direction.

Preferably, the inside diameter of the sieve holes is in the range of 1 to 5 mm.

Preferably, the inside diameter of the sieve holes is 3 mm.

Preferably, the inside diameter of the sieve holes is 5 mm.

Preferably, the fan 2 is a circulating fan.

Preferably, the kiln consists of six insulating layers, the inner wall of the kiln sequentially forms an air inlet side with the flow dividing cover 3, the partition end wall and the flow dividing plate 4, and the side wall of the kiln sequentially forms an air receiving side with the flow dividing plate 4 and the partition end wall; the air outlet of the fan 2 is arranged on a channel communicated with the air inlet side, and the channel on the air inlet side is arranged on the initial wood blank and the trolley 19.6 through the sieve holes.

As shown in fig. 3 and 8, the temperature-rising kiln, the drying kiln and the carbonization kiln are provided with microwave sources, the microwave sources include microwave power supplies 11, microwave magnetrons 10 and microwave crack antennas 9, the microwave power supplies 11 are electrically connected with the microwave magnetrons 10, the microwave magnetrons 10 are connected with the microwave crack antennas 9 vertically arranged in the lower working area, the microwave crack antennas 9 are uniformly distributed and arranged on the inner sides of the two splitter plates 4 along the moving direction of the trolley, the microwave crack antennas 9 are provided with microwave radiation holes 9.1 facing the wood blank, and the microwave radiation holes 9.1 are arranged in a staggered manner in the vertical direction.

Preferably, a steam spray pipe 7 communicated with a steam source is arranged in the heating kiln, the drying kiln, the carbonization kiln and the quick cooling kiln; the heating kiln, the drying kiln and the carbonization kiln are provided with heat exchangers 15, the quick cooling kiln is internally provided with a refrigerator, and the heat exchangers 15 and the refrigerator sequentially form a loop with the fan 2, the flow dividing cover 3 and the lower working area.

Preferably, in a heating kiln, a drying kiln and a carbonization kiln, the heat exchanger 15 in the kiln is a radiant tube 8, and the radiant tube 8 is accommodated in an accommodating space formed by the fan 2, the flow dividing cover 3, the partition plate 6 and the kiln wall; the radiant tube 8 in the heating kiln, the drying kiln and the carbonization kiln is used for maintaining the temperature in the kiln.

Preferably, the heat exchanger 15 arranged in the fast cooling kiln is a water-cooling exchanger, and the water-cooling exchanger in the fast cooling kiln is used for fast heat dissipation of the kiln.

The steam source is a high pressure steam boiler.

Preferably, in the rapid cooling kiln, a water-cooling exchanger is arranged in a heat insulation space formed by the partition boards 6, two partition board openings 13 are arranged on one side of each partition board 6 close to the fan 2, one end of each second partition board 14 is connected with the partition board 6 in the middle of each opening, the other end of each second partition board is connected with the kiln wall on the air receiving side, an air suction opening and one partition board opening 13 of the fan 2 are opened in a space formed by the second partition board 14, the top of each partition board 6 and the flow dividing cover 3, an air outlet of the fan 2 is opened on the air inlet side, and the other partition board.

A spray pipe 17 communicated with a water source is arranged in the rewetting kiln.

And the spray pipe 17 in the moisture returning kiln is connected with an atomizer which is an atomizing nozzle.

Preferably, a microwave power supply 11 and a microwave magnetron 10 are arranged in the heat insulation space formed by the partition board 6, and a microwave source connecting pipe 12 is arranged at the end part of the microwave slot antenna 9 for receiving the microwave of the microwave source.

Preferably, the rated power of the microwave source is 915MHZ or 2450 HZ;

as shown in fig. 9-10, the transmission means comprises a gear 16, a driving motor 5 and a rack 18 cooperating with the gear 16; the rack 18 is arranged at the bottom of the trolley 19.6, and the bottom of each kiln is provided with a gear 16 which is in transmission connection with an output shaft of the driving motor 5 outside the kiln.

Preferably, the pressing device comprises a pressing strip 19.1, a cable 19.2, an elastic piece 19.4 and a rope pulling device 19.5; the initial wood blanks are stacked at intervals through parting strips 19.3, and the pressing strips 19.1 are arranged at the positions corresponding to the parting strips 19.3; the pressing devices are symmetrically arranged on two sides of the trolley 19.6 in the advancing direction of the trolley 19.6 at equal intervals, the rope pulling device 19.5 is arranged on the trolley, one end of the cable 19.2 is connected to the rope pulling device 19.5, the other end of the cable is connected to the pressing strip 19.1, and the elastic piece 19.4 is arranged in the cable 19.2.

Preferably, one end of the cable 19.2 is movably arranged on the rope pulling device 19.5, the other end of the cable forms a closed ring through a locking hoop, and one end of the elastic element 19.4 is connected with the closed ring; one end of a second cable is fixed on the pressing strip 19.1, the other end of the second cable forms a second closed ring through the locking hoop, and the other end of the elastic piece 19.4 is fixed on the second closed ring.

The cable 19.2 is a steel wire rope, and the elastic part 19.4 is a bidirectional hook spring.

Preferably, the end part of the kiln is provided with a kiln door cavity, the upper part in the kiln door cavity is provided with a winding drum mechanism, the winding drum mechanism comprises a winding drum 20.2 and a pull rope 20.3, a rotating shaft 20.1 connected with an output shaft of a motor is arranged in the winding drum, one end of the pull rope 20.3 is wound on the winding drum 20.2, and the other end of the pull rope is connected with the kiln door 20.5.

The furnace door cavity is composed of a heat insulation plate 20.4, the furnace door 20.5 is a furnace wall of the furnace along the advancing direction of the trolley 19.6 and is arranged at the lower part of the top wall, the top wall is provided with an opening, the furnace door 20.5 enters the furnace door cavity from the opening, and the top end of the furnace door 20.5 is fixedly provided with a limiting piece; when the movable door is closed, the limiting piece is tightly attached to the surface of the top wall of the kiln; a winding drum 20.2 is movably arranged at the upper part of the heat insulation plate 20.4, a rotating shaft 20.1 passes through a central through hole of the winding drum 20.2, and the rotating shaft 20.1 is connected with an output shaft of a motor; one end of the pull rope 20.3 is wound on the winding drum 20.2, and the other end is connected with the limiting piece.

Preferably, in the heating kiln, the drying kiln and the carbonization kiln, the kiln also comprises a thermometer which is a wet-dry bulb thermometer and is arranged on the top wall of the kiln and positioned on the air inlet side;

the furnace door 20.5 of the preferable heating furnace, the drying furnace, the carbonization furnace, the slow cooling furnace and the fast cooling furnace comprises at least one layer of heat-insulating layer; the interior of the oven door 20.5 of the preheating kiln and the moisture returning kiln is provided with a heat insulation layer, one side close to the adjacent oven door 20.5 is provided with a heat insulation layer, and the other side departing from the adjacent oven door 20.5 is provided with a microwave isolation layer. The heat insulating layer is made of heat insulating asbestos, the heat insulating layer is made of a silicon rubber sealing ring, and the microwave isolating layer is made of graphite.

Preferably, the continuous wood modification heat treatment system further comprises a trolley moving frame, the trolley moving frame is arranged at the door of a first kiln of the preheating kiln where the trolley 19.6 enters or the door of a last kiln where the trolley 19.6 leaves, and the height of the trolley 19.6 moving frame is consistent with the height of the bottom surface of the kiln; the trolley 19.6 moving frame comprises a frame and positioning blocks, the frame comprises two frames, the two frames are symmetrically arranged along the central axis of the trolley 19.6 moving frame along the advancing direction of the trolley 19.6, the positioning blocks are divided into two groups and are arranged in a mode of being tightly attached to the frame, one end of each positioning block is connected with the trolley 19.6 moving frame, and the other end of each positioning block is in contact with the ground.