JP2006057220A - Heat-treatment furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-treatment furnace enabling the change of the width of an opening formed on a sidewall according to the thickness of a strand group horizontally traveling in the heat-treatment furnace. <P>SOLUTION: The heat-treatment furnace is provided with a heat-treatment chamber 31 having a pair of sidewalls 4, 6 provided with a plurality of slit openings 25, 27 through which a horizontally traveling strand group 3 is reciprocatively entering into and leaving from the chamber, and a means for heating the strand group 3 in the heat-treatment chamber 31. The sidewall is composed of perforated sidewalls 5, 7 having a plurality of slits 9, 11 horizontally directing the longitudinal direction of the slit, and mobile plates 13, 15 superposed to the outer side of the perforated sidewall in vertically slidable manner and having a plurality of slits 17, 19 horizontally directing the longitudinal direction of the slit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat treatment furnace used in a pre-process for producing polyacrylonitrile-based carbon fibers and the like. More specifically, the present invention relates to a heat treatment furnace for heat-treating polyacrylonitrile fibers and the like.

  Conventionally, flame-resistant fibers are produced by heat-treating polyacrylonitrile (PAN) fibers in an oxidizing atmosphere at 200 to 300 ° C. PAN-based fibers are usually put into a heat treatment furnace as bundled strands and subjected to flame resistance treatment.

  A schematic view of a conventionally used flameproofing apparatus is shown in FIG.

  The flameproofing apparatus 100 includes a heat treatment furnace 1 that performs flameproofing treatment of the PAN-based fibers 2 and folding rollers 21 a, 21 b, 23 a, and 23 b for supplying the PAN-based fibers 2 to the heat treatment furnace 1. The heat treatment furnace 1 includes a pair of perforated side walls 5 and 7 having a plurality of slits 9 and 11 through which a PAN fiber strand enters and exits the heat treatment furnace. In the heat treatment chamber 31 of the heat treatment furnace 1, a strand group (pass) 3 in which a large number of strands introduced into the heat treatment furnace through the slits of the perforated side walls 5 or 7 are arranged in a horizontal plane is formed and traveled. is doing. The strand group 3 forming this path again passes through the slit in the perforated side wall and is discharged from the heat treatment furnace 1. The discharged strand group 3 is folded back by a predetermined set of folding rollers 21a, 21b, 23a, and 23b disposed outside the heat treatment furnace and repeatedly supplied to the heat treatment furnace 1 to form a plurality of stages. .

  By passing a high-temperature oxidizing gas through the path in the heat treatment furnace, the oxidation reaction of the strands can be promoted and the reaction heat of the strands can be removed to produce the flameproof fiber 29.

  By the way, in order to stably produce the flameproof fiber, it is necessary to apply hot air having a uniform temperature to the path.

  However, the vicinity of the slit formed on the perforated side wall of the heat treatment furnace is lower in temperature than the center part of the furnace due to the influence of strands and outside air repeatedly supplied to the flameproofing furnace.

  Such partial temperature non-uniformity causes problems such as short reaction due to short effective reaction length of the strands in the flameproofing furnace, a decrease in production efficiency, and breakage of the strands due to abnormal heat generation. Arise.

  Furthermore, oxidization of PAN-based fibers generates harmful substances such as cyanide, ammonia and carbon monoxide in the heat treatment chamber. If the gas in the heat treatment chamber leaks outside, the environment around the heat treatment furnace will be adversely affected.

  Therefore, the slit formed in the side wall of the heat treatment furnace needs to prevent the inflow of outside air to the heat treatment furnace and the outflow of gas to the outside by minimizing the gap generated between the traveling strand groups.

  On the other hand, the strand group which performs a flameproofing process differs in the thickness when driving | running | working horizontally according to the single fiber number and fiber diameter of the filament which comprises a strand. Further, when the strands are replaced, the ends of the strands are entangled and run in the heat treatment furnace. For this reason, the slit width of the side wall needs to be a width that matches the maximum thickness of the strand group, but the above-described problem occurs because a gap is formed between the slit and the strand group during normal heat treatment. ing.

In addition, as a prior art relevant to this invention, there exists the heat processing furnace of patent document 1. FIG. In this heat treatment furnace, the slit width is adjusted by rotating an interval adjusting member disposed in the opening of the slit around a rotation axis provided perpendicular to the traveling direction of the strand.
JP 2004-27414 A (Claims)

  An object of the present invention is to provide a heat treatment furnace capable of changing the slit width formed on the side wall in accordance with the thickness of the strand group running in the heat treatment furnace.

  The present invention for achieving the above object is as follows.

  [1] A heat treatment furnace comprising a heat treatment chamber having a pair of side walls having a plurality of slit-like openings through which a group of strands that fold and run horizontally enters and exits, and means for heating the strand group in the heat treatment chamber. The side wall is a perforated side wall in which a plurality of slits are formed horizontally in the longitudinal direction, and a movable plate that is slidably stacked on the outside of the perforated side wall in the vertical direction. And a movable plate having a plurality of slits formed in the heat treatment furnace.

  [2] The heat treatment furnace according to [1], wherein the slits formed in the perforated side wall and the movable plate have an equal width and an equal interval, respectively.

  According to the present invention, the widths of the plurality of openings of the heat treatment furnace can be changed simultaneously by sliding the movable plate disposed on the perforated side wall of the heat treatment furnace according to the thickness of the strand group. Therefore, since the heat treatment furnace of the present invention can prevent the flow of outside air into the heat treatment furnace, high-quality flame-resistant fibers can be stably produced. Further, it is possible to prevent the harmful substances generated by the heat treatment of the PAN-based fibers from flowing out of the furnace and to ensure the safety of the work.

  FIG. 1 is a schematic cross-sectional view showing an example of a flameproofing apparatus using the heat treatment furnace of the present invention.

  In FIG. 1, 100 is a flameproofing treatment apparatus, 1 is a heat treatment furnace, and 3 is a strand group of PAN fibers that run horizontally. The heat treatment furnace 1 has a pair of opposing side walls 4 and 6. The side walls 4 and 6 include perforated side walls 5 and 7 and movable plates 13 and 15 that are slidably adhered to the outside of the perforated side walls 5 and 7.

  A plurality of (five in the present figure) slits 9 and 11 are formed in the perforated side walls 5 and 7, respectively, with their longitudinal directions horizontal. The same number of slits 17 and 19 as the perforated side walls 5 and 7 are formed in the movable plates 13 and 15 disposed on the outer surfaces of the perforated side walls 5 and 7, respectively.

  An exploded view in which the side wall 4 is disassembled into the perforated side wall 5 and the movable plate 13 is shown in FIG. 2A, and an assembly view in which the movable plate 13 is attached to the perforated side wall 5 is shown in FIG.

  The perforated side wall 5 and the movable plate 13 are formed with equal width slits 9 and 17 at equal intervals, respectively. The slit widths of the slits 9 and 17 formed in the perforated side wall 5 and the movable plate 13 are the same. The movable plate 13 can be slid in the width direction (vertical direction) of the slits 9 and 17. By sliding the movable plate 13 according to the thickness of the traveling strand group 3, the opening width of the slit-like opening 25 formed in the side wall 4 of the heat treatment furnace 1 can be adjusted.

  As shown in FIG. 1, on the outside of the heat treatment furnace 1, folding rollers 21 a and 21 b are disposed facing the side wall 4, and folding rollers 23 a and 23 b are disposed facing the side wall 6.

  The strand group 3 is introduced into the heat treatment chamber 31 of the heat treatment furnace 1 through the uppermost opening of the slit-shaped openings 25 formed in the side wall 4 of the heat treatment furnace. The strand group 3 is flameproofed by being heated by a heating means (not shown) in the heat treatment chamber 31 in an oxidizing atmosphere. Thereafter, the strand group 3 passes through the uppermost opening 27 formed in the side wall 6 and is discharged out of the heat treatment furnace 1. The discharged strand group 3 is folded back by a folding roller 23 a provided outside the heat treatment furnace, and then introduced into the heat treatment chamber 31 of the heat treatment furnace 1 from the second-stage opening formed in the side wall 7 again. Thus, while the PAN fiber 2 travels while being folded by the folding roller, supply and discharge to the heat treatment furnace are repeated, and after the flame resistance treatment is repeatedly performed, the PAN fiber 2 becomes the flame resistant fiber 29.

  Note that the movable plates 13 and 15 can be slid in the slit width direction by a known means such as a wire or a cam mechanism.

  In FIG. 1, the movable plates 13 and 15 are disposed on the outer surfaces of the perforated side walls 5 and 7 of the heat treatment furnace so that the opening widths of the slit-like openings 25 and 27 can be adjusted. May be formed by stacking two movable plates without providing a perforated side wall.

  The slit width formed in the perforated side walls 5 and 7 and the movable plates 13 and 15 may be the same between the plurality of slits formed in the perforated side wall and the movable plate, and between the perforated side wall and the movable plate. The slit widths are not necessarily the same.

It is a schematic sectional drawing which shows an example of the flameproofing processing apparatus using the heat processing furnace of this invention. (A) is the exploded view which decomposed | disassembled the side wall into the perforated side wall and the movable plate, and (B) is the assembly figure which attached the movable plate to the perforated side wall. It is a schematic sectional drawing which shows the flameproofing processing apparatus using the conventional heat processing furnace.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat processing furnace 2 PAN fiber 3 Strand group 4, 6 Side wall 5, 7 Perforated side wall 9, 11, 17, 19 Slit 13, 15 Movable plate 21a, 21b, 23a, 23b Folding roller 25, 27 Opening part 29 Flame resistance Fiber 100 Flameproofing equipment

Claims (2)

A heat treatment furnace comprising a heat treatment chamber having a pair of side walls having a plurality of slit-like openings through which a strand group that turns and runs horizontally enters and exits, and means for heating the strand group in the heat treatment chamber, The side wall is a perforated side wall in which a plurality of slits are formed horizontally in the longitudinal direction, and a movable plate that is slidably stacked on the outside of the perforated side wall in the vertical direction, and the longitudinal direction is formed horizontally. A heat treatment furnace comprising a movable plate having a plurality of slits. The heat treatment furnace according to claim 1, wherein the slits formed in the perforated side wall and the movable plate have an equal width and an equal interval, respectively.

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