阅读说明：本技术 一种真空式蒸汽热处理木材设备及其处理方法 (Vacuum type steam heat treatment wood equipment and treatment method thereof ) 是由 曹永建 李兴伟 符韵林 赖敏婷 马红霞 高婕 于 2021-01-19 设计创作，主要内容包括：本发明公开了一种真空式蒸汽热处理木材设备及其处理方法,设备包括处理箱、蒸汽发生器、真空泵、控制面板以及电源；所述处理箱的箱壁上设有蒸汽入口、真空入口,所述蒸汽发生器与蒸汽入口连接,真空泵与真空入口连接；处理箱内壁面上设有多根热电偶；蒸汽发生器、真空泵、热电偶、电源分别与控制面板电连接。本发明采用真空式蒸汽热处理木材,真空及蒸气环境可以避免木材在高温状态下自燃。同时蒸汽不仅可作为传热介质又可作为保护介质,而且还可减少干燥过程中木材细胞皱缩现象的发生,提高木材的干燥质量。本发明涉及木材加工技术领域。(The invention discloses vacuum type steam heat treatment wood equipment and a treatment method thereof, wherein the equipment comprises a treatment box, a steam generator, a vacuum pump, a control panel and a power supply; a steam inlet and a vacuum inlet are formed in the wall of the treatment box, the steam generator is connected with the steam inlet, and the vacuum pump is connected with the vacuum inlet; a plurality of thermocouples are arranged on the inner wall surface of the treatment box; the steam generator, the vacuum pump, the thermocouple and the power supply are respectively and electrically connected with the control panel. The invention adopts vacuum steam heat treatment to the wood, and the vacuum and steam environment can avoid the spontaneous combustion of the wood in a high temperature state. Meanwhile, the steam not only can be used as a heat transfer medium but also can be used as a protection medium, and the occurrence of the shrinkage phenomenon of wood cells in the drying process can be reduced, so that the drying quality of the wood is improved. The invention relates to the technical field of wood processing.)

1. A vacuum type steam heat treatment wood device is characterized by comprising a treatment box, a steam generator, a vacuum pump, a control panel and a power supply; a steam inlet and a vacuum inlet are formed in the wall of the treatment box, the steam generator is connected with the steam inlet, and the vacuum pump is connected with the vacuum inlet; a plurality of thermocouples are arranged on the inner wall surface of the treatment box; the steam generator, the vacuum pump, the thermocouple and the power supply are respectively and electrically connected with the control panel.

2. The vacuum type steam heat treatment wood equipment as claimed in claim 1, wherein the thermocouples are symmetrically arranged on the inner wall surfaces of both sides of the treatment tank, and four thermocouples are arranged on the inner wall surface of each side.

3. The apparatus for vacuum steam heat treatment of wood as claimed in claim 2, wherein the distance between the end of the wood to be dried and the thermocouple is 15cm or more.

4. The vacuum steam heat treatment wood equipment according to claim 1, wherein the wall of the treatment box is further provided with an air inlet.

5. The vacuum type steam heat treatment wood equipment as claimed in claim 4, wherein the wall of the treatment box is also provided with a sewage draining outlet.

6. The vacuum type steam heat treatment wood equipment as claimed in claim 5, wherein the air inlet and the sewage discharge port are provided with electromagnetic valves, and the electromagnetic valves are electrically connected with the control panel.

7. The vacuum type steam heat treatment wood equipment as claimed in claim 1, wherein a dry bulb thermometer and a wet bulb thermometer are arranged in the treatment box, and the dry bulb thermometer and the wet bulb thermometer are respectively and electrically connected with the control panel.

8. The vacuum type steam heat treatment wood equipment as claimed in claim 1, wherein the steam generator is externally connected with a water tank, and a water pump is arranged on a connecting pipeline of the steam generator and the water tank.

9. Method for treating wood with a vacuum steam heat treatment wood plant according to any of claims 1 to 8, characterized in that it comprises the following steps:

putting wood to be dried into a treatment box;

the control panel controls the thermocouple in the treatment box to heat, so that the temperature in the treatment box is increased from room temperature to 100 ℃, and the temperature rising speed is 1.5 ℃/min; meanwhile, the control panel controls the steam generator to continuously introduce steam into the treatment box and keeps the temperature in the treatment box to be reduced to 100 ℃ after the treatment is finished;

the control panel controls a thermocouple in the treatment box to heat, so that the temperature in the box is increased from 100 ℃ to the temperature required by heat treatment, and the temperature increase speed is 1 ℃/min; starting to heat up from 100 ℃ in the box, starting to vacuumize by turning on the vacuum pump, and when the vacuum degree in the box reaches-0.08 MPa, keeping the vacuum degree until the temperature in the box is reduced to 100 ℃ after the treatment is finished.

10. The method according to claim 9, wherein the vacuum pump is turned off and the air inlet is opened to return the air pressure in the chamber to the normal pressure when the temperature in the chamber is lowered to 100 ℃.

Technical Field

The invention relates to the technical field of wood processing, in particular to vacuum type steam heat treatment wood equipment and a treatment method thereof.

Background

Wood contains a certain amount of moisture. The amount of water in the wood varies with the species, age and season of felling. In order to ensure the quality and prolong the service life of the wood and the wooden products, proper measures must be taken to reduce the moisture (water content) in the wood to a certain degree. To reduce the moisture content of the wood, the temperature of the wood is increased to evaporate and move the moisture in the wood outward, so that the moisture rapidly leaves the wood in the air with a certain flow speed, thereby achieving the purpose of drying.

The conventional wood drying equipment at present has the problems of high energy consumption and easy spontaneous combustion of the wood at a high temperature, the fast-growing wood of the artificial forest is easy to crack and deform in the drying process, the cell wall of the wood is easy to shrink in the drying process, and the drying quality is low.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings of the prior art and provides vacuum type steam heat treatment equipment for wood. Meanwhile, the steam not only can be used as a heat transfer medium but also can be used as a protection medium, and the occurrence of the shrinkage phenomenon of wood cells in the drying process can be reduced, so that the drying quality of the wood is improved.

Another object of the present invention is to provide a method for vacuum steam heat-treating wood.

The purpose of the invention can be realized by the following technical scheme: a vacuum type steam heat treatment wood device comprises a treatment box, a steam generator, a vacuum pump, a control panel and a power supply; a steam inlet and a vacuum inlet are formed in the wall of the treatment box, the steam generator is connected with the steam inlet, and the vacuum pump is connected with the vacuum inlet; a plurality of thermocouples are arranged on the inner wall surface of the treatment box; the steam generator, the vacuum pump, the thermocouple and the power supply are respectively and electrically connected with the control panel.

Furthermore, the thermocouples are symmetrically arranged on the inner wall surfaces of two sides of the treatment box, and four thermocouples are arranged on the inner wall surface of each side. The symmetrically distributed thermocouples make the heat distribution in the treatment tank more uniform.

Further, the distance between the end of the wood to be dried and the thermocouple is more than or equal to 15 cm. The heating of the end regions can be made to substantially coincide with the heating of the main body regions of the wood.

Furthermore, an air inlet is also arranged on the wall of the treatment box. The air inlet is used for opening the air inlet after the wood drying treatment is finished, so that the outside atmosphere enters the treatment box, and the air pressure in the box is recovered to the normal pressure state.

Furthermore, a sewage draining outlet is also formed in the wall of the treatment box. The effect of drain is, in wood drying process, through opening the drain, can be with the discharge of the volatile substances that flow out among the wood heat treatment process.

Furthermore, electromagnetic valves are arranged at the air inlet and the sewage discharge port and are electrically connected with the control panel. The electric opening or closing of the air inlet and the sewage draining outlet is realized through the electromagnetic valve.

Furthermore, a dry bulb thermometer and a wet bulb thermometer are further arranged in the treatment box, and the dry bulb thermometer and the wet bulb thermometer are respectively and electrically connected with the control panel. Dry bulb thermometers and wet bulb thermometers are used to measure the temperature and humidity inside the treatment chamber.

Furthermore, the steam generator is connected with a water tank, and a water pump is arranged on a connecting pipeline between the steam generator and the water tank. A water tank and a water pump provide a water source for the steam generator.

The other purpose of the invention can be realized by the following technical scheme: a method for treating wood by vacuum steam heat treatment comprises the following steps:

putting wood to be dried into a treatment box;

the control panel controls the thermocouple in the treatment box to heat, so that the temperature in the treatment box is increased from room temperature to 100 ℃, and the temperature rising speed is 1.5 ℃/min; meanwhile, the control panel controls the steam generator to continuously introduce steam into the treatment box and keeps the temperature in the treatment box to be reduced to 100 ℃ after the treatment is finished;

the control panel controls a thermocouple in the treatment box to heat, so that the temperature in the box is increased from 100 ℃ to the temperature required by heat treatment, and the temperature increase speed is 1 ℃/min; starting to heat up from 100 ℃ in the box, starting to vacuumize by turning on the vacuum pump, and when the vacuum degree in the box reaches-0.08 MPa, keeping the vacuum degree until the temperature in the box is reduced to 100 ℃ after the treatment is finished.

Further, after the treatment is finished, when the temperature in the box is reduced to 100 ℃, the vacuum pump is closed, and the air inlet is opened, so that the air pressure in the box is restored to the normal pressure state.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. the invention has no oxygen in the processing box under the vacuum condition, thereby avoiding the danger of flammability of wood at high temperature. Meanwhile, the steam is used as a heat transfer medium and a protective medium, and when the steam is used as the heat transfer medium, heat can be transferred, so that the temperature in the box is uniform; when the wood is used as a protective medium, certain moisture is provided for the wood, so that the risk that the wood is easy to spontaneously combust at a high temperature is avoided; in addition, the existence of the steam provides certain moisture for the wood cell wall, has great promotion effect on the recovery of the shrinking cells, and can improve the drying quality of the treated wood.

2. The invention dries the wood under the vacuum condition, and because the environmental temperature in the treatment box is 10 ℃ lower than the conventional heat treatment temperature under the pressure condition, the invention has basically the same treatment effect with the conventional heat treatment, can reduce the treatment energy consumption and improve the treatment efficiency.

Drawings

FIG. 1 is a schematic view showing the construction of an apparatus for vacuum steam heat-treating wood according to an embodiment of the present invention.

Wherein: 1: treatment box, 2: steam generator, 3: vacuum pump, 4: control panel, 5: power supply, 6: thermocouple, 7: air intake port, 8: drain, 9: water tank, 10: and (4) a water pump.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

As shown in fig. 1, a vacuum type steam heat treatment apparatus for treating wood includes a treatment tank 1, a steam generator 2, a vacuum pump 3, a control panel 4, and a power source 5. The wall of the treatment box is provided with a steam inlet and a vacuum inlet, the steam generator is connected with the steam inlet, and the vacuum pump is connected with the vacuum inlet. The steam generator is used for generating steam and is communicated into the treatment tank, the steam generator is also connected with an external water tank 9, a water pump 10 is arranged on a connecting pipeline, and the water tank and the water pump can provide water sources for the steam generator. The vacuum pump is used for vacuumizing the air in the treatment box. Four thermocouples 6 are symmetrically arranged on the inner wall surfaces of two sides of the treatment box respectively and are used for generating heat for drying the wood. When placing the wood to be dried in the treatment chamber, the end of the wood to be dried should be distanced from the thermocouple by a distance of at least 15cm, so that the heating of the end area is substantially identical to the heating of the main area of the wood.

The steam generator, the vacuum pump, the thermocouple and the power supply are respectively and electrically connected with the control panel. The control panel can control the opening or closing of the steam generator and the vacuum pump, and meanwhile, the temperature rising speed of the thermocouple can be set on the control panel. In order to facilitate observation of the temperature and humidity in the treatment box, a dry bulb thermometer and a wet bulb thermometer (not shown in the figure) are also arranged in the treatment box, and the dry bulb thermometer and the wet bulb thermometer are respectively and electrically connected with the control panel. The dry bulb thermometer and the wet bulb thermometer are respectively used for measuring the temperature and the humidity in the treatment box and displaying the temperature and the humidity on the control panel, and when the temperature and the humidity exceed set values, the control panel prompts an over-temperature alarm and an over-humidity alarm.

As shown in figure 1, the wall of the treatment box is also provided with an air inlet 7 and a sewage outlet 8, the air inlet and the sewage outlet are both provided with electromagnetic valves, and the electromagnetic valves are electrically connected with a control panel. The air inlet is opened through the electromagnetic valve after the wood drying treatment is finished, so that the outside atmosphere enters the treatment box, and the air pressure in the box is recovered to the normal pressure state. The drain outlet is used for discharging volatile substances flowing out in the wood heat treatment process by controlling the electromagnetic valve and opening the drain outlet in the wood drying process.

The method for treating wood by using the vacuum type steam heat treatment wood equipment comprises the following steps:

(1) opening a box door of the treatment box, putting wood to be dried into the treatment box, and keeping the distance between the end part of the wood and the thermocouple at least 15 cm;

(2) the thermocouple in the treatment box is controlled to heat through the control panel, so that the temperature in the treatment box is raised to 100 ℃ from room temperature, and the temperature raising speed is 1.5 ℃/min. Meanwhile, the steam generator is controlled by the control panel to continuously introduce steam into the treatment box, and the temperature in the treatment box is kept to be reduced to 100 ℃ after the treatment is finished.

(3) The thermocouple in the treatment box is controlled to heat through the control panel, so that the temperature in the box is increased from 100 ℃ to the temperature required by heat treatment, and the temperature increase speed is 1 ℃/min. Starting to heat up from 100 ℃ in the box, starting to vacuumize by turning on the vacuum pump, and when the vacuum degree in the box reaches-0.08 MPa, keeping the vacuum degree until the temperature in the box is reduced to 100 ℃ after the treatment is finished.

(4) After the wood drying treatment is finished, when the temperature in the box is reduced to 100 ℃, the vacuum pump and the steam generator are closed, and the air inlet is opened, so that the air pressure in the box is restored to the normal pressure state.

The following data were obtained by treating eucalyptus urophylla, eucalyptus urophylla and eucalyptus urophylla wood with the vacuum steam heat treatment apparatus of the present invention at different heat treatment temperatures.

Example one

When the heat treatment temperature is 200 ℃, the treatment time is 5 hours, and the vacuum degree is-0.08 MPa, the air-dried volume anti-drying shrinkage performance of the eucalyptus urophylla wood is improved by 48.27%, and the full-dried volume anti-drying shrinkage performance is improved by 25.81%.

Example two

When the heat treatment temperature is 200 ℃, the treatment time is 5 hours, and the vacuum degree is-0.08 MPa, the air-dried volume anti-drying shrinkage performance of the eucalyptus urophylla wood is improved by 53.88 percent, and the full-dried volume anti-drying shrinkage performance is improved by 34.82 percent.

EXAMPLE III

When the heat treatment temperature is 200 ℃, the treatment time is 5 hours, and the vacuum degree is-0.08 MPa, the air-dried volume anti-drying shrinkage performance of the eucalyptus grandis wood is improved by 60.05 percent; the dry shrinkage resistance of the full dry volume is improved by 41.31 percent.

Example four

When the heat treatment temperature is 220 ℃, the treatment time is 5 hours, and the vacuum degree is-0.08 MPa, the air-dried volume dry shrinkage resistance of the eucalyptus urophylla wood is improved by 68.24%, and the full-dried volume dry shrinkage resistance is improved by 51.34%.

EXAMPLE five

When the heat treatment temperature is 220 ℃, the treatment time is 5 hours, and the vacuum degree is-0.08 MPa, the air-dry volume anti-drying shrinkage performance of the eucalyptus urophylla wood is improved by 70.43 percent, and the full-dry volume anti-drying shrinkage performance is improved by 51.63 percent.

EXAMPLE six

When the heat treatment temperature is 220 ℃, the treatment time is 5 hours, and the vacuum degree is-0.08 MPa, the air-dried volume anti-drying shrinkage performance of the eucalyptus grandis wood is improved by 78.25%; the dry shrinkage resistance of the full dry volume is improved by 57.48 percent.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.