JPH06229681A - Fluidized bed apparatus for treating wire or band material - Google Patents

Abstract

PURPOSE:To stabilize the fluidization of a fluidized bed apparatus by a method wherein cylindrical bodies having an inlet hole and an outlet hole for a running thread or band material are partly formed of perforated plates or porous plates with fine through-holes leading to the outside of the fluidized bed and having diameters smaller than the mean diameter of fluidized particles. CONSTITUTION:A running thread- or band-like material, e.g. a carbon fiber precursor, is introduced into a fluidized bed 1 through an inlet hole 6 provided in the side wall of a frame 2, continuously or intermittently travels through the fluidized bed 2 as it is kept in specified conditions, and goes outside through an outlet hole 7 provided on the side of the frame 2. The inlet and outlet holes 6 and 7 each consist of a cylindrical body 8 which is partly formed of a perforated plate or a porous plate 9 with fine through-holes leading to the outside of the fluidized bed 1 and having diameters smaller than the mean diameter of fluidized particles. Thereby, the fluidized particles deposit and naturally form a dike surrounding the material to be treated, so that an excellent sealing effect is produced and the fluidized particles are kept from leaking.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire, filament, tape or the like made of metal or organic polymer, which is heated, cooled, or reacted while being continuously or intermittently run in a fluidized bed. Alternatively, the present invention relates to a fluidized bed apparatus for treating strips. This apparatus can also be used when heat-treating a carbon fiber precursor such as a polyacrylonitrile fiber.

[0002]

2. Description of the Related Art A fluidized bed apparatus for treating a wire or a band while traveling is known as, for example, a patenting treatment apparatus for steel wires and a heat treatment apparatus for polyacrylonitrile fibers. In these fluidized bed apparatuses, in order to run the object to be processed in the fluidized bed, a means for introducing and discharging the object to be treated into the fluidized bed without leaking the fluidized particles to the outside becomes a problem. As its means, after introducing the object to be treated from the surface of the fluidized bed into the fluidized bed, and after traveling in the fluidized bed by changing the traveling direction of the object to be treated using a guide or the like,
A fluidized bed device that changes the traveling direction of the article to be treated from the surface of the fluidized bed again using a guide, etc., and an introduction hole for the article to be treated at a position midway between the fluidized bed surface on the side wall of the fluidized bed frame and the dispersion plate. There are known a fluidized bed apparatus provided with a discharge hole and a fluidized bed apparatus in which a mesh belt is run in the fluidized bed and an object to be processed is placed on the mesh belt to carry out the processing.

Among these fluidized bed apparatuses, the apparatus for introducing the object to be treated into and out of the fluidized bed through the introduction / extraction hole causes little damage to the object to be treated and is economically advantageous. But,
In this device, it is necessary to rationally prevent the fluidized particles from leaking from the inlet / outlet hole. As a specific means therefor, for example, in Japanese Patent Laid-Open No. 1-192825, a cylindrical pressure seal chamber is provided in the introduction / extraction hole of the object to be treated, and the pressure seal chamber is slightly higher than the furnace pressure. A device for supplying a sealing gas having a pressure of Further, in JP-A-4-214186, a fluid particle retention chamber is provided in the vicinity of an inlet / outlet port of the object to be treated, the fluidized particles flowing out into the residence chamber are suctioned and captured, and a bridge is provided around the object to be treated. There has been proposed a device for forming and sealing.

[0004]

However, the apparatus disclosed in Japanese Patent Laid-Open No. 1-192825 has a problem that it is difficult to adjust the balance between the opening area of the inlet / outlet hole and the pressure sealing pressure. . In addition, JP-A-4-2141
The apparatus described in Japanese Patent No. 86 has a problem that the portion in the vicinity of the introduction / extraction hole is in a poor fluidized state and damages the object to be processed. In particular, when dealing with delicate objects such as polyacrylonitrile fiber, the damage has been a major problem.

The present invention solves the above-mentioned problems of the introduction and exit holes of the object to be processed in a fluidized bed apparatus in which a traveling line or a belt-like object is the object to be processed, and adjustment and maintenance are easy, It is an object of the present invention to provide an economical fluid bed apparatus for treating a linear or strip material which does not cause damage, and a fluid bed apparatus suitable for heating a carbon fiber precursor in a linear or strip shape.

[0006]

In order to solve the above-mentioned problems, the present invention is a fluidized bed apparatus in which a traveling line or a belt-shaped article is the object to be treated. The holes and the lead-out holes that lead out the object to be processed outside the fluidized bed,
Each is formed into a tubular body, and a part of the tubular body is composed of a porous plate or a porous plate having through holes having a diameter smaller than the average diameter of the fluidized particles communicating outside the fluidized bed. A fluidized bed apparatus for continuous treatment of a wire or a strip is provided.

In the present invention, the fluidized bed apparatus is a fluidized bed apparatus in which a traveling line or belt-like carbon fiber precursor is used as an object to be treated, and gas is blown into the fluidized bed. A fluidized bed apparatus for treating a wire or a strip is provided, in which a nozzle is provided in proximity to the fluidized bed side openings of the inlet hole and the outlet hole.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and Functions The fluidized bed apparatus for treating a wire or strip (hereinafter abbreviated as a fluidized bed apparatus) of the present invention will be described with reference to the drawings with reference to embodiments. FIG. 1 is a schematic cross-sectional view showing an embodiment of a fluidized bed apparatus according to the present invention along the traveling direction of the object to be treated, FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. 1, and FIG. It is a perspective view of a hole and a lead-out hole portion.

In the fluidized bed apparatus of the present invention, the frame 2 forming the fluidized bed 1, the fluidized gas dispersion plate 3, and the fluidized particles 4 are used.
A known material can be used for. The frame 2 is made of metal, FRP, ceramic material, etc., and the planar shape of the fluidized bed 1 may be rectangular or circular, and the upper portion thereof may be open to the atmosphere or may be closed. The dispersion plate 3 is made of a metal or a ceramic material such as a porous plate or a porous plate, and the fluidized particles 4 are made suitable for processing purposes such as heat medium and refrigerant.
Carbon, alumina, silicon carbide, and other powders can be selected and used. It is also possible to provide a heating tube or a cooling tube for heat exchange in the fluidized bed 1. For fluidization, a gas suitable for forming a desired processing atmosphere is used.
The fluidizing gas is supplied from the supply pipe 12 to the lower side of the dispersion plate, fluidizes the fluidized particles 4, and is discharged to the outside of the system through the exhaust pipe 13.

A wire or strip, which is the object 5 to be treated, such as a wire or strip of carbon fiber precursor, is introduced into the fluidized bed 1 through an introduction hole 6 attached to a side wall of the frame 2.
It travels continuously or intermittently in the fluidized bed 1 kept under the required processing conditions, and is led out to the outside from the lead-out hole 7 attached to the lateral portion of the frame body 2. The introduction hole 6 and the extraction hole 7 (hereinafter, referred to as introduction holes) are usually provided on the side wall of the frame body 2.
It is provided at an appropriate position between the surface of the fluidized bed 1 and the dispersion plate 3.

Inlet / outlet holes 6 and 7 of the fluidized bed apparatus of the present invention.
Are each formed of a tubular body 8, and the tubular body 8
Is partially composed of a porous plate or a porous plate (hereinafter abbreviated as porous plate) 9 having through holes having a diameter smaller than the average diameter of fluidized particles communicating outside the fluidized bed 1. When processing a plurality of objects 5, a plurality of pairs of inlet / outlet holes 6 and 7 can be arranged vertically or horizontally and one or a plurality of objects 5 can be passed through each inlet / outlet hole. .

The shape of the cylindrical body 8 is a round cylinder, a rectangular cylinder, or the like, and the cross-sectional shape thereof is not limited and may be reduced or expanded in the axial direction. The material is selected according to the required heat resistance and corrosion resistance. The introduction / extraction holes 6 and 7 have an effect of smoothly introducing and extracting the object to be treated 5 and preventing the fluidized particles 4 from leaking to the outside. That is, since the pressure in the fluidized bed 1 is usually higher than the atmospheric pressure, when a hole is provided in the frame body 2 below the surface of the fluidized bed 1, the fluidized particles 4 are ejected from the hole together with the fluidized gas. However, in the inlet / outlet holes 6 and 7 provided in the fluidized bed apparatus of the present invention, a part of the cylindrical body 8 forming the inlet / outlet holes is smaller than the average diameter of the fluidized particles 4 communicating with the outside of the fluidized bed 1. Since it is composed of the perforated plate 9 having the through holes, the fluidized gas and the fluidized particles 4 flowing into the inlet / outlet holes 6 and 7 reach the portion of the perforated plate 9, and only the fluidized gas is perforated. Remaining fluid particles 4 released from the atmosphere through the through hole 9
Are deposited on that portion to form the bank 10. The bank 10 seals the inlet / outlet holes 6 and 7, and prevents the fluidized particles 4 from leaking.

If the pore size of the perforated plate 9 is too small, clogging is likely to occur. Therefore, it is generally 40 to 80% of the diameter of the fluidized particles 4, and preferably 50 to 70%. The perforated plate 9 is
It can be provided at one location or in a plurality of locations side by side in the circumferential or axial direction. The longer the length of the porous plate 9 portion in the axial direction of the tubular body 8, the more stable the sealing performance can be obtained, but if it is too long, the running resistance of the object to be treated 5 increases,
Risk of damage due to abrasion. If it is too short, the sealing effect becomes small, and there is a risk that the fluidized particles 4 will be ejected due to pressure fluctuations in the furnace of the fluidized bed 1. In order to set an appropriate length, an introduction hole (outlet hole) for testing having the same size as the inlet hole to be attached to the frame body 2 is attached to the fluidized bed 1 except that it has a long perforated plate. Maintaining the normal state, the pressure change in the fluidized particles in the test introduction hole is measured in the axial direction, and the necessary length for reducing the pressure in the introduction hole to the atmospheric pressure is obtained. Generally, in order to obtain the value in this way, a suitable length is 1 to 5 times the required length, and usually 1.5 to 2 times.
20 to 10 for a normal fluidized bed operating under atmospheric pressure
It will be about 0 mm.

Further, it is preferable that the cross-sectional areas of the inlet / outlet holes 6 and 7 are set to the minimum necessary. If the cross-sectional area is too large, a large amount of fluidized gas and fluidized particles 4 will flow out of the fluidized bed 1, causing fluidized bed 1 near the inlet / outlet holes 6 and 7 to be poorly fluidized, and treating the fluidized particles 4 that have flowed out. Or cause replenishment problems. If it is too small, the object to be processed comes into contact with the wall surface of the tubular body 8 and is easily damaged, which is not preferable. It may be unavoidable that a small amount of fluid particles flow out from the introduction / extraction holes 6 and 7, but in such a case, for example, a hopper is attached to the outer end of the introduction / extraction holes 6 and 7. The fluidized particles 4 may be collected and returned to the fluidized bed.

By the way, when a linear or strip-shaped carbon fiber precursor is heat-treated using the fluidized bed apparatus of the present invention,
Under the accurate and uniform temperature condition, the object to be processed 5 can be easily processed without being damaged. Examples of the carbon fiber precursor include polyacrylonitrile fiber, regenerated cellulose fiber, phenol fiber, pitch fiber filament, strand, tow, woven fabric, knitted fabric, and non-woven fabric. The heat treatment is usually an exothermic reaction performed at a temperature of 300 ° C. or lower by blowing a fluidized gas containing air as a main component. When particularly strict temperature control is required as in this case, the fluidized bed 1 of the inlet / outlet holes 6 and 7 is
An air supply nozzle 11 for blowing gas into the fluidized bed 1 is preferably provided near the side opening. Air supply nozzle 11
Has a function of supplementing the fluidizing gas diffused to the outside from the inlet / outlet holes 6 and 7 and keeping the flow state near the inlet / outlet holes 6 and 7 uniform. Reference numeral 14 is an air supply pipe for fluidizing gas supplemented from the air supply nozzle 11. Since proper fluidization is maintained in this way, the temperature in the fluidized bed 1 becomes uniform, the heat transfer between the fluidized bed and the object to be treated becomes good, and the object 5 to be treated is precisely temperature-controlled. Can be managed. Air supply nozzle 1
Although the structure of No. 1 is not limited, if a blowing plate is made of a metal or ceramic porous plate or tube, a perforated plate, etc., the blown gas is uniformly dispersed and the backflow of the fluidized particles 4 can be prevented, which is convenient. Is good.

[0016]

EXAMPLE A fluidized bed apparatus of the present invention was manufactured, and the polyacrylonitrile fiber was heat-treated using the apparatus.
explain.

The fluidized bed has a total length of 100 cm and a width of 15 c
m, the maximum operating temperature was 300 ° C., and a fluidized bed apparatus of the present invention similar to that shown in FIG. 1 was produced for heat treatment of carbon fiber precursor polyacrylonitrile fiber. In this fluidized bed apparatus, a porous plate of sintered metal was used as a dispersion plate, and graphite particles having a diameter of 0.35 mm were loaded on the dispersion plate as a depth of 400 mm when stationary. At both ends of the frame forming the fluidized bed, a rectangular tube introduction hole and a discharge hole having a height of 20 mm and a width of 100 mm were provided at a position of 200 mm on the dispersion plate. The upper side and the lower side of the central portion of the square tube were made of a sintered wire mesh having a width of 100 mm, a length of 100 mm, and an average hole diameter of 0.15 mm, which face each other. In addition, an air supply nozzle of a sintered metal tube having a diameter of 20 mm and a length of 100 mm was attached in parallel with the fluidized bed side opening and immediately above the fluidized bed side opening of the introduction hole and the derivation hole.

160 m ³ / in the fluidized particles through the dispersion plate
Blows in heated air for an hour and the temperature in the fluidized bed is 25
A fluidized bed was formed while controlling the temperature to 0 ° C.
As a result of operating for a while under these operating conditions and observing the state inside the inlet / outlet hole, it was confirmed that the fluidized particles were deposited and filled in the perforated plate portion to form a bank. Then, when the pressure in the fluidized particles in the inlet / outlet hole was measured, it was confirmed that the pressure was reduced to atmospheric pressure at a position of about 20 mm from the end of the deposited particles on the fluidized bed side. Further, as a result of observing the movement of the fluidized particles in the seal cylinder while gradually closing the opening area of the perforated plate by closing the perforated plate portion of the cylinder with an iron plate, the conditions in the fluidized bed and the introduction / extraction holes are stable. The range is 1.5 to 2 which is the length for reducing the pressure in the seal cylinder to the atmospheric pressure.
It turned out to be double. The results are shown in Table 1 and FIG.

[0019]

[Table 1] Next, from the introduction hole to the exit hole, the single yarn fineness is 1 denier, the number of filaments is 24,000, and the number of twists is 7 turns / m.
The polyacrylonitrile fiber (1) was run at a speed of 1 m / min and heat-treated at 250 ° C. During this period, heated air of 250 ° C. was supplied to the air supply nozzle at different flow rates, the fluidized state was observed, and the fiber tension and fluff during running were measured. The results are shown in Table 2. As the amount of air supplied from the air supply nozzle is reduced, the fluidization near the inlet / outlet hole changes, gradually becoming a poor flow state, the resistance due to the fluidized particles increases, and the tension of the running fiber increases, The number of fluffs generated on heat-treated fibers has increased. The results are shown in Table 2.

[0020]

[Table 2]

[0021]

In the fluidized bed apparatus of the present invention, the fluidizing gas is discharged to the outside in the perforated plate portion in the introduction / extraction hole of the object to be treated attached to the fluidized bed frame, and the fluidized particles are naturally accumulated. Form a bank that surrounds the object to be processed. This bank has a sealing effect, and greatly reduces the amount of fluidized gas, especially fluidized particles, leaking from the fluidized bed to the outside through the inlet / outlet hole. Therefore, the fluidization of the fluidized bed is stable, and accurate and uniform processing conditions are maintained. In addition, the running resistance of the object to be processed when passing through the introduction / extraction hole is small, and it has an effect of making it less likely to be damaged by rubbing.

When the fluidized bed apparatus of the present invention is used for heat treatment of a carbon fiber precursor which requires accurate and uniform temperature conditions and is easily damaged, high quality carbon fibers can be obtained, which is preferable. is there. The heat treatment of the carbon fiber precursor is
This is an oxidation reaction accompanied by a large amount of heat generation, and when the temperature rises above a predetermined level, the object to be treated may be burnt out. Therefore, providing an air supply nozzle close to the fluidized bed side opening,
If proper fluidization is performed to stabilize the fluidized bed, the temperature in the fluidized bed is maintained uniform, which is effective for producing high-quality carbon fiber. Of course, the air supply nozzle can be provided in processing operations other than the heat treatment of the carbon fiber precursor.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a fluidized bed apparatus according to an embodiment of the present invention, taken along the traveling direction of a workpiece.

FIG. 2 is a sectional view taken along the line AA ′ of FIG.

FIG. 3 is a perspective view of an introduction hole and an extraction hole portion.

FIG. 4 is a graph showing the relationship between the seal length and the pressure in the seal cylinder.

[Explanation of symbols]

1: Fluidized bed 2: Frame 3: Dispersion plate 4: Fluidized particles 5: Object to be treated 6: Introduction hole 7: Derivation hole 8: Cylindrical body 9: Perforated plate or porous plate 10: Formed by fluidized particles Bank 11: Air supply nozzle 12: Supply pipe 13: Exhaust pipe 14: Air supply pipe

Claims (2)

[Claims] 1. A fluidized bed apparatus using a traveling line or a strip as an object to be treated, and an introduction hole for introducing the object to be treated into the fluidized bed, and an outlet hole for leading out the object to be treated outside the fluidized bed. Are each formed into a tubular body, and a part of the tubular body is composed of a porous plate or a porous plate having through holes having a diameter smaller than the average diameter of the fluidized particles communicating with the outside of the fluidized bed. A fluidized bed apparatus for treating a line or a strip, which is characterized in that 2. A fluidized bed apparatus using a traveling line or belt-shaped carbon fiber precursor as an object to be treated, wherein an air supply nozzle for blowing gas into the fluidized bed has The fluidized bed apparatus for treating a wire or strip according to claim 1, wherein the fluidized bed apparatus is provided in the vicinity of the fluidized bed side opening.