阅读说明：本技术 一种预氧化炉用回风箱及预氧化炉 (Air return box for pre-oxidation furnace and pre-oxidation furnace ) 是由 张瑜 傅建根 金振峰 王永法 卫国军 吴钟翔 陈建林 于 2019-09-18 设计创作，主要内容包括：本发明属于氧化炉技术领域,具体涉及一种预氧化炉用回风箱及预氧化炉；其中,预氧化炉用回风箱,包括沿预氧化炉的回风方向依次设置的第一箱体和第二箱体,第一箱体与第二箱体以预设间距分布；第一箱体朝向回风方向的一侧具有第一回风口；第二箱体包括沿预氧化炉的回风方向依次分布的回风腔体和新风腔体,回风腔体朝向回风方向的一侧具有第二回风口,新风腔体具有用于引入新风的新风口。本发明的预氧化炉用回风箱,沿回风方向具有两级回风,回风充分,不会对预氧化炉内的热空气流造成影响。(The invention belongs to the technical field of oxidation furnaces, and particularly relates to a return air box for a pre-oxidation furnace and the pre-oxidation furnace; the air return box for the pre-oxidation furnace comprises a first box body and a second box body which are sequentially arranged along the air return direction of the pre-oxidation furnace, wherein the first box body and the second box body are distributed at a preset interval; one side of the first box body facing the air return direction is provided with a first air return opening; the second box body comprises a return air cavity and a fresh air cavity which are sequentially distributed along the return air direction of the pre-oxidation furnace, one side of the return air cavity facing the return air direction is provided with a second return air inlet, and the fresh air cavity is provided with a fresh air inlet for introducing fresh air. The air return box for the pre-oxidation furnace has two stages of return air along the return air direction, the return air is sufficient, and the hot air flow in the pre-oxidation furnace cannot be influenced.)

1. The air return box for the pre-oxidation furnace is characterized by comprising a first box body and a second box body which are sequentially arranged along the air return direction of the pre-oxidation furnace, wherein the first box body and the second box body are distributed at a preset interval;

One side of the first box body facing the air return direction is provided with a first air return opening;

The second box body comprises a return air cavity and a fresh air cavity which are sequentially distributed along the return air direction of the pre-oxidation furnace, one side of the return air cavity facing the return air direction is provided with a second return air inlet, and the fresh air cavity is provided with a fresh air inlet for introducing fresh air.

2. the air return box for the pre-oxidation furnace as claimed in claim 1, wherein the fresh air chamber has a fresh air inlet communicated with the outside.

3. the air return box for the pre-oxidation furnace as claimed in claim 1, wherein the air outlet direction of the fresh air inlet of the fresh air cavity is perpendicular to the air return direction of the pre-oxidation furnace.

4. The air return box for the pre-oxidation furnace as claimed in claim 3, wherein the fresh air inlet of the fresh air cavity is circumferentially distributed in a direction perpendicular to the return air direction of the pre-oxidation furnace.

5. the air return box for the pre-oxidation furnace as set forth in claim 1, wherein the predetermined distance between the first and second boxes is greater than 60 mm.

6. the air return box for the pre-oxidation furnace as claimed in claim 1, wherein the first return air inlet of the first box is provided with a first mesh plate, and the second return air inlet of the second box is provided with a second mesh plate.

7. A pre-oxidation oven characterized in that a plurality of return air boxes according to any one of claims 1 to 6 are provided in the pre-oxidation oven at intervals perpendicular to the return air direction.

8. The pre-oxidation furnace of claim 7, wherein the pre-oxidation furnace is provided with drawing and inserting ports corresponding to the first mesh plate and the second mesh plate respectively, and the drawing and inserting ports are provided with heat-preservation sealing plugs.

9. The pre-oxidation oven according to claim 8, wherein a suction passage is provided corresponding to the suction port; when the heat-insulating sealing plug is separated from the extraction opening, the air suction channel recovers the air flow overflowing from the extraction opening.

10. The pre-oxidation oven according to claim 7, wherein the pre-oxidation oven is used for manufacturing carbon fibers.

Technical Field

the invention belongs to the technical field of oxidation furnaces, and particularly relates to a return air box for a pre-oxidation furnace and the pre-oxidation furnace.

background

In the production process of the carbon fiber, the preoxidation of the precursor plays a role in starting and stopping, and the preoxidation process of the precursor directly influences the yield and the performance of the carbon fiber. The purpose of the pre-oxidation process is to convert thermoplastic PAN linear macromolecular chains into non-plastic heat-resistant trapezoidal structures, so that the thermoplastic PAN linear macromolecular chains are not melted and non-combustible at high carbonization temperature, maintain the fiber shape, and the thermodynamics is in a stable state, and finally are converted into carbon fibers with disordered-layer graphite structures. The pre-oxidation furnace is produced according to the requirements of the pre-oxidation process.

Existing pre-oxidation ovens generally comprise:

The end walls at two ends of the furnace body are provided with a plurality of groups of through holes which are distributed along the height direction and are oppositely arranged, and the through holes are used for penetrating through fibers; wherein, the furnace body is sealed with gas except the through hole;

The furnace body is internally provided with wire moving channels which are distributed along the length direction of the furnace body and used as a space for fiber pre-oxidation treatment;

An air duct is arranged in the furnace body, a heater and a fan are arranged in the air duct, the heater is positioned at the upstream of the fan, and the fan blows hot air heated by the heater in the air duct into the wire moving channel;

The air return device is arranged at the end part of the wire moving channel and comprises a plurality of air return boxes which are arranged at a vertical distance; an air inlet and an air outlet of the air return box are respectively communicated with the wire feeding channel and the upstream end of the air channel;

the air outlet device is arranged in the wire moving channel and comprises a plurality of distributors arranged at vertical intervals so as to ensure that hot air is uniformly blown into the wire moving channel; the spacing spaces between adjacent distributors form a tow channel;

The fan enables hot air to circulate through the air outlet device, the wire feeding channel and the air return device;

And the guide rollers are used for guiding the fibers to pass through the through holes, the vertical space between the adjacent air return boxes and the tow channel between the adjacent distributors in a snake-shaped distribution manner.

Although the existing air return boxes have high air return efficiency, the gaps between the adjacent air return boxes easily cause that a small part of hot air is not sucked by the air return opening of the air return boxes, thereby influencing the preoxidation treatment of fibers.

Disclosure of Invention

Based on the defects in the prior art, the invention provides an air return box for a pre-oxidation furnace and the pre-oxidation furnace.

In order to achieve the purpose, the invention adopts the following technical scheme:

A return air box for a pre-oxidation furnace comprises a first box body and a second box body which are sequentially arranged along the return air direction of the pre-oxidation furnace, wherein the first box body and the second box body are distributed at a preset interval;

One side of the first box body facing the air return direction is provided with a first air return opening;

the second box body comprises a return air cavity and a fresh air cavity which are sequentially distributed along the return air direction of the pre-oxidation furnace, one side of the return air cavity facing the return air direction is provided with a second return air inlet, and the fresh air cavity is provided with a fresh air inlet for introducing fresh air.

as a preferred scheme, the fresh air cavity is provided with a fresh air inlet communicated with the outside.

As a preferred scheme, the air outlet direction of the fresh air inlet of the fresh air cavity is perpendicular to the air return direction of the pre-oxidation furnace.

As the preferred scheme, the fresh air inlet of the fresh air cavity is circumferentially distributed along the direction vertical to the return air of the pre-oxidation furnace.

preferably, the preset distance between the first box body and the second box body is larger than 60 mm.

Preferably, a first mesh plate is arranged at the first air return opening of the first box body, and a second mesh plate is arranged at the second air return opening of the second box body.

The invention also provides a pre-oxidation furnace, wherein a plurality of air return boxes which are arranged in the pre-oxidation furnace at intervals vertical to the air return direction are arranged in the pre-oxidation furnace.

preferably, the pre-oxidation furnace is provided with drawing and inserting ports which respectively correspond to the first mesh plate and the second mesh plate one by one, and the drawing and inserting ports are provided with heat-preservation sealing plugs.

as a preferred scheme, an air suction channel is arranged corresponding to the drawing and inserting port; when the heat-insulating sealing plug is separated from the extraction opening, the air suction channel recovers the air flow overflowing from the extraction opening.

preferably, the pre-oxidation oven is used for manufacturing carbon fibers.

Compared with the prior art, the invention has the beneficial effects that:

the air return box for the pre-oxidation furnace has two stages of return air along the return air direction, the return air is sufficient, and the hot air flow in the pre-oxidation furnace cannot be influenced.

The pre-oxidation furnace has good pre-oxidation treatment effect on fibers.

Drawings

FIG. 1 is a schematic structural view of a return air box for a pre-oxidation furnace according to a first embodiment of the present invention;

FIG. 2 is a schematic vertical sectional view of a pre-oxidation furnace according to a first embodiment of the present invention;

FIG. 3 is a schematic view of a horizontal sectional structure of a pre-oxidation furnace according to a first embodiment of the present invention;

FIG. 4 is an enlarged view of section I of FIG. 2;

FIG. 5 is a schematic view showing the structure of a distributor of a pre-oxidation furnace according to a first embodiment of the present invention;

FIG. 6 is a schematic view showing the construction of a first casing of a distributor of a pre-oxidation oven according to a first embodiment of the present invention;

FIG. 7 is a schematic structural view of a second casing of a distributor of the pre-oxidation oven according to the first embodiment of the present invention;

FIG. 8 is an enlarged view of section II of FIG. 2;

FIG. 9 is a schematic structural view of a return box for a pre-oxidation furnace according to a second embodiment of the present invention;

FIG. 10 is a schematic view of a horizontal cross-sectional structure of a pre-oxidation furnace in an on-line cleaning process according to a second embodiment of the present invention;

FIG. 11 is an enlarged view of a portion of a drawer of a pre-oxidation oven according to a second embodiment of the present invention;

FIG. 12 is an enlarged view of a portion of the extraction opening of the pre-oxidation oven according to the second embodiment of the present invention (the heat-retaining sealing plug is not shown);

fig. 13 is a schematic side view of a pre-oxidation furnace according to a second embodiment of the present invention.

Detailed Description

in order to more clearly illustrate the embodiments of the present invention, the following description will explain the embodiments of the present invention with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.