阅读说明：本技术 一种降醛热处理工艺以及连续式节能降醛热处理窑 (Aldehyde-reducing heat treatment process and continuous energy-saving aldehyde-reducing heat treatment kiln ) 是由 张焕兵 叶昌海 于 2020-04-29 设计创作，主要内容包括：本发明涉及板材降醛技术领域,公开了降醛热处理工艺,包括如下步骤：将人造板材放入降醛热处理窑中热处理；热处理后的人造板材放入养生平衡室中养生；热处理方式采用预热-加热-恒温的多阶段降醛方式,恒温温度为110℃～130℃,恒温时间为1h～4h；预热温度为50℃～80℃,预热时间为0.5h～6h。公开了一种连续式节能降醛热处理窑,包括顺次相接的预热窑段、降醛窑段和平衡窑段,预热窑段开设有进料口,平衡窑段开设有出料口；降醛窑段配置有供热组件,平衡窑段与所述预热窑段之间配备有气流输送组件,气流输送组件用于将平衡窑段的气流输送至预热窑段。采用本发明的技术,能够有效达到降醛效果,同时降醛处理周期短,提高生产效率。(The invention relates to the technical field of plate aldehyde reduction, and discloses an aldehyde reduction heat treatment process, which comprises the following steps: putting the artificial board into an aldehyde-reducing heat treatment kiln for heat treatment; placing the artificial board after heat treatment into a health-preserving balance chamber for preserving; the heat treatment mode adopts a preheating-heating-constant temperature multi-stage aldehyde reduction mode, the constant temperature is 110-130 ℃, and the constant temperature time is 1-4 h; the preheating temperature is 50-80 ℃, and the preheating time is 0.5-6 h. The continuous energy-saving and aldehyde-reducing heat treatment kiln comprises a preheating kiln section, an aldehyde-reducing kiln section and a balance kiln section which are connected in sequence, wherein the preheating kiln section is provided with a feed inlet, and the balance kiln section is provided with a discharge outlet; the aldehyde reduction kiln section is provided with a heat supply assembly, an airflow conveying assembly is arranged between the balance kiln section and the preheating kiln section, and the airflow conveying assembly is used for conveying airflow of the balance kiln section to the preheating kiln section. By adopting the technology of the invention, the effect of reducing aldehyde can be effectively achieved, meanwhile, the treatment period of reducing aldehyde is short, and the production efficiency is improved.)

1. The aldehyde-reducing heat treatment process is characterized by comprising the following steps of:

s1, putting the artificial board into a formaldehyde-reducing heat treatment kiln for heat treatment;

s2, placing the artificial board subjected to heat treatment in the S1 into a curing balance chamber for curing;

in the S1, a preheating-heating-constant-temperature multi-stage aldehyde reduction mode is adopted as a heat treatment mode, the constant temperature is 110-130 ℃, and the constant temperature time is 1-4 h; the preheating temperature is 50-80 ℃, and the preheating time is 0.5-6 h.

2. The aldehyde-reducing heat treatment process according to claim 1, wherein the moisture content of the artificial board before heat treatment is 10-15%; the density of the artificial board is 0.6g/cm³～0.9g/cm³。

3. The aldehyde-reducing heat treatment process according to claim 1, wherein the curing time in the S2 is 3 to 7 days.

4. A continuous energy-saving and aldehyde-reducing heat treatment kiln is characterized by comprising a preheating kiln section, an aldehyde-reducing kiln section and a balance kiln section which are sequentially connected, wherein the preheating kiln section is provided with a feed inlet, and the balance kiln section is provided with a discharge outlet;

the aldehyde reduction kiln section is provided with a heat supply assembly, an airflow conveying assembly is arranged between the balance kiln section and the preheating kiln section, and the airflow conveying assembly is used for conveying airflow of the balance kiln section to the preheating kiln section.

5. The continuous energy-saving and aldehyde-reducing heat treatment kiln according to claim 4, wherein the gas flow conveying assembly comprises a heat exchange fan and a gas flow conveying pipeline which are arranged outside the balance kiln section, the heat exchange fan is connected with one end of the gas flow conveying pipeline, and the other end of the gas flow conveying pipeline is connected with the preheating kiln section.

6. The continuous energy saving aldehyde reducing heat treatment kiln according to claim 4 or 5, wherein the preheating kiln section, the aldehyde reducing kiln section and the balancing kiln section are each configured with a gas flow circulation assembly.

7. The continuous energy-saving aldehyde-reducing heat treatment kiln according to claim 4, wherein the aldehyde-reducing kiln section is provided with a spray humidity control system, the spray humidity control system comprises spray pipes and spray nozzles, the spray nozzles are uniformly distributed along the length direction of the spray pipes, the spray pipes are arranged on the inner surface of a kiln cover of the aldehyde-reducing kiln section, the spray pipes are communicated with a water source, and the water source is provided with a valve.

8. The continuous energy-saving formaldehyde-reducing heat treatment kiln according to claim 4 or 5, characterized in that the waste gas treatment component comprises a waste gas collection box, a rotary spray tower, a UV photo-oxygen catalysis device, a centrifugal fan, a silencer and a waste gas discharge pipe which are connected in sequence, wherein the formaldehyde-reducing kiln section is provided with a gas discharge pipe, and the gas discharge pipe is communicated with the waste gas collection box.

9. The continuous energy-saving and aldehyde-reducing heat treatment kiln as claimed in claim 4, wherein the heat supply assembly comprises a heat radiator, the heat radiator is a bimetal composite fin heat exchanger, and the heat exchange medium of the bimetal composite fin heat exchanger is heat conduction oil or water vapor.

10. The continuous energy-saving aldehyde-reducing heat treatment kiln according to claim 9, further comprising a control assembly, wherein the control assembly comprises a temperature sensing instrument, a solenoid valve and a control system box, the control system box is arranged outside the aldehyde-reducing kiln section, the temperature sensing instrument is mounted inside the aldehyde-reducing kiln section, the solenoid valve is mounted in the feeding section of the radiator, and the temperature sensing instrument and the solenoid valve are respectively connected with the control system box.

Technical Field

The invention relates to the technical field of plate aldehyde reduction, in particular to an aldehyde reduction heat treatment process and a continuous energy-saving aldehyde reduction heat treatment kiln.

Background

The adhesive used in the artificial board comprises urea-formaldehyde resin as the main component. The urea-formaldehyde resin can continuously release formaldehyde to the surrounding environment when the environmental conditions such as temperature, humidity and the like change, the release period can reach more than ten years, and the urea-formaldehyde resin is a main body for causing formaldehyde pollution in indoor air. Therefore, it is important to reduce the formaldehyde content in the board.

Patent publication No. CN102041890A discloses a method for manufacturing a composite floor board with low formaldehyde emission by heat treatment. The composite floor is put into a heat treatment box to be heated at the temperature of 60-110 ℃ for 8-96 hours. The long-time medium-low temperature heating mode is adopted, so that the problems of long treatment period and poor aldehyde removal effect exist.

In the process of reducing aldehyde of the artificial board by adopting heat treatment, the artificial board is mostly placed in the box body for heat treatment, however, the box body used as a heat treatment chamber has the problems of low treatment capacity, high energy consumption and long treatment period of the artificial board. At present, a kiln body specially used for aldehyde reduction heat treatment does not appear, and the kiln body mainly used for processing artificial plates at present is a thermal modification kiln, a drying kiln and the like.

Patent publication No. CN207594014U discloses a wood thermal modification kiln. In the technical scheme of the patent, the plate is discharged out of the kiln body after being subjected to heat treatment and cooling, and residual airflow in the kiln body still has heat, but the residual airflow is not effectively utilized, so that waste is caused. When the next batch of plates need to be subjected to heat treatment, the air is heated to a specific temperature and then is subjected to heat preservation treatment to achieve the heat treatment effect, in the process, the difference between the temperature of the air flow in the kiln body and the specific temperature is too large, so that the heating time of the heating assembly is too long, the treatment period of the plates is long, and the equipment is long in operation time and high in energy consumption.

Disclosure of Invention

Through a great deal of research, after the artificial board is pressed and attached, the formaldehyde content in the artificial board can be effectively reduced and the formaldehyde removal time can be shortened by a multi-stage formaldehyde reduction mode of preheating, heating and keeping constant temperature. And by combining the treatment capacity and the heat energy loss of the plates in the heat treatment process, a continuous formaldehyde-reducing heat treatment kiln is independently designed, and the heat treatment kiln can be used for treating large batches of plates and a circulating heat reflux mode is adopted, so that the effects of short heat treatment period, reduction of thermal loss and improvement of heat efficiency of the plates can be achieved.

Therefore, the first object of the present invention is to provide a formaldehyde-reducing heat treatment process, comprising the following steps:

s1, putting the artificial board into a formaldehyde-reducing heat treatment kiln for heat treatment;

s2, placing the artificial board subjected to heat treatment in the S1 into a curing balance chamber for curing;

in the S1, a preheating-heating-constant-temperature multi-stage aldehyde reduction mode is adopted as a heat treatment mode, the constant temperature is 110-130 ℃, and the constant temperature time is 1-4 h; (ii) a The preheating temperature is 50-80 ℃, and the preheating time is 0.5-6 h.

If the artificial board is subjected to long-time high-temperature treatment, the thermal decomposition of the urea-formaldehyde resin can be caused, and the more serious the thermal decomposition, the internal bonding strength of the urea-formaldehyde resin and the artificial board is reduced, which is not beneficial to the later use of the artificial board. If the artificial board is subjected to long-time low-temperature treatment, the release of formaldehyde is not facilitated, and the plasticization of the adhesive is also not facilitated.

According to the method, a multi-stage formaldehyde reducing mode of preheating, heating and constant temperature is adopted, a part of formaldehyde is released from the preheated board, then the formaldehyde is further released in the heating and constant temperature process, the aim of removing the formaldehyde is achieved by gradually releasing the formaldehyde, and the bonding strength of the adhesive and the artificial board can be well maintained.

The method comprises the following steps:

the artificial board is subjected to multilayer bonding through an adhesive, the adhesive contains urea-formaldehyde resin, the urea-formaldehyde resin cannot be completely cured at high temperature in a short time, the artificial board is subjected to preheating treatment to promote the curing of the urea-formaldehyde resin, so that the bound formaldehyde is firmly locked, a part of free formaldehyde can be released, and then the free formaldehyde is further released in the heating and constant-temperature processes. In addition, the molecule rearrangement-methylene bond rearrangement of the solidified thermoplastic part can be carried out to form a more compact network structure, so that the bonding strength between the artificial boards is enhanced.

In the heating and constant temperature treatment stages, on one hand, along with the rise of the heat treatment temperature, the heat movement of formaldehyde molecules in the heat treatment process is accelerated, and the release of free formaldehyde remained in the artificial board to the outside is promoted; on the other hand, the pore structure characteristics of the artificial board are also changed by the increase of the temperature, so that the adsorption capacity and the adsorption capacity of the artificial board to formaldehyde are reduced, the further release of the formaldehyde in the artificial board is facilitated, and the formaldehyde in the artificial board is fully released in the heat treatment stage. After the urea-formaldehyde resin is subjected to preheating treatment, the urea-formaldehyde resin is partially cured and is not easy to decompose at high temperature, and the urea-formaldehyde resin can be prevented from decomposing at high temperature for a long time so as to release free formaldehyde.

The second purpose of the invention is to provide a continuous energy-saving and aldehyde-reducing heat treatment kiln, which comprises a preheating kiln section, an aldehyde-reducing kiln section and a balance kiln section which are connected in sequence, wherein the preheating kiln section is provided with a feed inlet, and the balance kiln section is provided with a discharge outlet; the aldehyde reduction kiln section is provided with a heat supply assembly, an airflow conveying assembly is arranged between the balance kiln section and the preheating kiln section, and the airflow conveying assembly is used for conveying airflow of the balance kiln section to the preheating kiln section.

In the invention, the preheating process is carried out in the preheating kiln section, and the heating and constant temperature process is carried out in the aldehyde-reducing kiln section.

This application carries out thermal treatment to the artificial board through the mode that adopts continuous type backward flow heat supply, can reduce the heat consumption among the thermal treatment process, carries the air current of balance kiln section to preheating the kiln section through the air current conveying subassembly in, has realized the retrieval and utilization of hot gas flow. Because the kiln section is configured in a sectional mode, continuous batch processing of the aldehyde-reducing heat treatment process of the artificial plates can be realized, so that the processing requirements of large-batch plates can be met, and the production efficiency is improved.

The invention has the beneficial effects that:

(1) by adopting a multi-stage formaldehyde reducing mode of preheating, heating and constant temperature, a part of formaldehyde is released from the preheated board, then formaldehyde is further released in the heating and constant temperature process, the formaldehyde reducing purpose is achieved by gradually releasing formaldehyde, the bonding strength of the adhesive and the artificial board can be well maintained, and the formaldehyde reducing period can be shortened;

(2) the heat consumption in the heat treatment process can be reduced by a continuous reflux heat supply mode, the heat treatment period is shortened, and the continuous batch treatment of the aldehyde-reducing heat treatment process for the artificial plates can be realized by combining the sectional configuration of the kiln section, so that the production efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 is a schematic structural diagram of a continuous energy-saving aldehyde-reducing heat treatment kiln in example 8;

FIG. 2 is a schematic view showing the structure of the inner side of a kiln cover in the aldehyde reducing kiln section in example 8;

FIG. 3 is a schematic view showing the structure of the inner wall of the kiln in the aldehyde-reducing kiln section in example 8;

fig. 4 is a sectional view taken along a-a in fig. 1.

Reference numerals: 100- -preheating the kiln section; 110- -a feed inlet; 200-aldehyde reduction kiln section; 211-water spray pipe; 212- -an atomizer head; 221- -exhaust collection tank; 222- -rotating spray tower; 223- -UV photo-oxygen catalysis equipment; 224-centrifugal fan; 225-a muffler; 226- -exhaust gas discharge pipe; 230- -exhaust pipe; 300- -balance kiln section; 310- -discharge hole; 331- -Heat exchange Fan; 332- -gas flow delivery channel; a. an airflow circulation assembly; b. a heat sink; c. a first delivery port; d. and (5) conveying the belt.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

In the description of the present invention, it should be noted that if the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which is usually placed when the product of the present invention is used, the description is merely for convenience of describing the present invention and simplifying the description, but the indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation and operation, and thus, cannot be understood as the limitation of the present invention.

In the description of the present invention, it should be further noted that unless otherwise explicitly stated or limited, the terms "disposed," "configured," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.