JPS6361412B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a centrifugal spinning device for pitch fibers, and more specifically, it relates to a centrifugal spinning device for pitch fibers, and more specifically, it relates to a centrifugal spinning device for pitch fibers, and more specifically, it is a method for spinning pitch fibers using isotropic pitch or mesophase pitch starting from petroleum or coal pitch. This invention relates to a spinning nozzle device in a centrifugal spinning apparatus for pitch fiber, which produces pitch fiber, which is a precursor of carbon fiber, by heating and melting the same and centrifugally spinning it.

(Prior Art) A centrifugal spinning device for pitch fibers generally includes a spinner disk consisting of a top wall, a bottom wall, and a side wall, and a rotational drive shaft attached to the center of the bottom wall of the spinner disk. The molten pitch is spun into pitch fibers by rotating the spinner disk at high speed by rotating a rotary drive shaft while supplying the molten pitch into the spinner disk. That is, the molten pitch is discharged from the spinning nozzle hole by the centrifugal force generated by the high-speed rotation of the spinner disk, and the discharged molten pitch is stretched and fiberized by the air friction generated around it due to the high-speed rotation of the spinner disk, and becomes pitch fiber. becomes.

In such a centrifugal spinning device, the spinning nozzle hole for discharging molten pitch is generally simply a round hole bored in the side wall of the spinner disk or near the side wall of the bottom wall. Showa 58
-Disclosed in Publication No. 203105.

(Problems to be Solved by the Invention) As the operating time increases, the nozzle holes in the centrifugal spinning apparatus undergo wear and deformation, causing changes in the operating conditions. Therefore, the conventional spinning nozzle hole, which is simply a round hole, becomes unusable after a certain period of time, and the entire spinner disk must be replaced, which is uneconomical.

Also, after driving for a long time or after stopping the operation,
Since the pitches attached around the exit side of the spinning nozzle hole were partially oxidized or carbonized, it was also necessary to replace the entire spinner disk.

Furthermore, in order to change the diameter of pitch fibers, it is necessary to manufacture a separate spinner disk equipped with spinning nozzle holes having different diameters, and in this sense, the conventional spinning nozzle holes are also uneconomical.

An object of the present invention is to solve the problems of the prior art, and to eliminate the need to replace the entire spinner disk even if the spinning nozzle hole becomes worn or the pitch around its exit becomes oxidized or carbonized. It is an object of the present invention to provide a spinning nozzle device for a melt pitch centrifugal spinning device that does not require manufacturing a separate spinner disk each time the diameter of a spinning nozzle hole is changed and is therefore extremely economical.

(Means for Solving the Problems) In order to achieve the above object, the spinning nozzle device in the centrifugal spinning device for melt pitch according to the present invention has the following features:
The spinner disk has a convex nozzle structure consisting of a shaft and a head, and has at least one spinning nozzle hole in the axial direction; Forming a mounting hole for the nozzle structure, and inserting the shaft portion of the convex nozzle structure into the mounting hole such that the head thereof is located on the inner peripheral surface side of the side wall of the spinner disk, The structure is characterized in that it is removably attached to the side wall of the spinner disk.

(Embodiments) Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a spinning nozzle device 100 in a centrifugal spinning device for pitch fibers according to the present invention. It has a convex nozzle structure 102 with one spinning nozzle hole 102c in the center.

As shown in FIG. 4, the centrifugal spinning device 2 has a spinner disk 6, and a side wall 6c of the spinner disk 6 is provided with mounting holes 104 for a plurality of convex nozzle structures 102 along its circumferential direction. The convex nozzle structure 102 is attached to the side wall of the spinner disk 12 by inserting the shaft portion 102a into the mounting hole 104 so that the head 102b is located on the inner peripheral surface 106 side of the side wall 6c of the spinner disk 6. It is removably attached to 6c.

Shaft 10 of preferably convex nozzle structure 102
2a is inserted at least partially into the mounting hole 104 with a light interference fit. A light interference fit is one in which the shaft portion 102a can be inserted into the mounting hole 104 by pushing it manually or by hitting it with a mallet. By creating such a fitted state, the shaft portion 102a can be easily pulled out from the mounting hole 104 by pushing it by hand or hitting it with a mallet when removing it.

In the embodiment shown in FIG. 1, both the shaft portion 102a and the mounting hole 104 have a constant diameter and are in a light interference fit over substantially the entire length. More specifically, when the diameter of the mounting hole 104 is D, the shaft portion 1
The diameter of 02a is approximately D ⁺⁰ _-0.1 .

Note that the shaft portion 102a and the mounting hole 104 are not limited to a straight shape with a constant diameter as shown in FIG. 1, but at least one of them may be tapered. For example, in the spinning nozzle device 100A shown in FIG. 2, the attachment hole 104 is straight with a constant diameter, and the shaft portion 102e of the convex nozzle structure 102A is tapered. In the nozzle device 100B, the shaft portion 102a of the convex nozzle structure 102 has a straight shape with a constant diameter, and the mounting hole 1
04B is tapered in the radial direction. Therefore, in the embodiment shown in FIG. 2, the shaft portion 102e of the convex nozzle structure 102A
04, there is a slight interference fit at the base of the shaft portion 102e, and in the embodiment shown in FIG.
The tip of the shaft portion 102a is in a light interference fit with the mounting hole 104B. Shaft portion 102e
Specifically, the degree of taper of both the mounting hole 104A and the mounting hole 104A is preferably in the range of approximately 1° to 8°.

In this way, by tapering at least one of the shaft portion 102a and the mounting hole 104, the fit between the two can be improved, and the shaft portion 102a can be easily inserted into and pulled out from the mounting hole 104, thereby forming a convex nozzle structure. can be easily replaced.

Head 10 of convex nozzle structure 102, 102A
2b, its inner surface 102f has mounting holes 104,1
It has a shape that follows and contacts the inner circumferential surface 106 of the side wall 6c of the spinner disk 6 around the spinner disk 6, and sealingly engages with the inner circumferential surface 106 by centrifugal force during operation.

Convex nozzle structure 102, 102A and mounting hole 1
04, 104B is basically the above-mentioned shaft portions 102a, 102e and the mounting holes 104, 1
This is done by a light interference fit between the two parts, but by making good use of the centrifugal force caused by the rotation of the spinner disk 12, and sealingly engaging the inner surface 102f of the head 102b with the inner circumferential surface 106, Its sealing performance is further improved.

Note that the convex nozzle structure 102 may be attached by cutting a thread in the shaft portion 102a and the attachment hole 104 and screwing it in, instead of depending on the selection of the fitting state as in the above embodiment.

FIG. 4 shows the entire centrifugal spinning device 2 including the spinning nozzle device 100 of the present invention. Centrifugal spinning device 2
The spinner disk 6 includes a top wall 6a having a central opening 4, a bottom wall 6b, and a side wall 6c located between the top wall 6a and the bottom wall 6b and provided with the spinning nozzle device 100 of the present invention; 6
A hollow rotary drive shaft (hereinafter referred to as a hollow rotary shaft) 10 is attached to the center of the bottom wall 6b with a bolt or the like.
It is equipped with Top wall 6a, bottom wall 6b, side wall 6c
is made of brass, for example.

Top wall 6a and bottom wall 6b of spinner disk 6
Planar heating elements 12a and 12b made of an electrically conductive heating material such as a Ni-Cr alloy are attached to the outer surfaces of the heating elements 12a and 12b in a fixed contact state. In the illustrated embodiment, the planar heating elements 12a, 12b are mounted by covering the planar heating elements 12a, 12b with cover plates 14a, 14b made of stainless steel or the like, and connecting the top wall 6a, bottom wall 6b, cover plate 14a, 14b and an appropriate number of bolts 16a, 16b (see Figures 5 and 6).
(see figure). Note that the mounting of the planar heating element is not limited to this. An opening 1 larger than the central hole 10a of the hollow rotating shaft 10 is provided in the center of the lower cover plate 14b.
8 is open.

The hollow rotating shaft 10 is rotatably supported within a hollow fixed shaft 22 via bearings 20a and 20b. A pulley 24 is attached to the top of the hollow rotating shaft 10, and as shown in FIG. The hollow rotary shaft 10 is rotationally driven by the motor 26.

The lower end of the fixed hollow shaft 22 is formed with a circumferential flange 22a that protrudes outward in the radial direction. It closes the central opening 4 and serves as an upper lid for it. A molten pitch supply pipe 30 is attached to the circumferential flange 22a, and its outlet is located within the spinner disk 6.

A pair of current supply terminals 32a, 32b, 34a, 34b are connected to the planar heating elements 12a, 12b, respectively, and a thermocouple 36 is connected to the spinner disk 6 as temperature detection means. Current supply terminals 32a, 34a are connected to lead wire 38a, and current supply terminals 32b, 34b are connected to lead wire 3.
8b, the thermocouple 36 is connected to the lead wires 38c,
38d, and these lead wires 38a
38d extends upward through the central hole 10a of the hollow rotating shaft 10.

From the outside of the hollow fixed shaft 22 to the upper part of the hollow rotating shaft 10 and the hollow fixed shaft 22, the hollow rotating shaft 10
A rotating energizing mechanism 40 is provided which is electrically connected to the lead wires 38a to 38d inside so that current can be supplied to these lead wires.

In the illustrated embodiment, the rotary energizing mechanism 40 includes conductive parts 4 each mounted on the outer periphery of the hollow rotating shaft 10.
2a, 42b, 42c, 42d, and a retainer 46 made of an insulating material attached to the hollow fixed shaft 22.
energizing brushes 48a, 48b, 48c, which are housed in the energizing brushes 48a, 46b, 46c, and 46d and are biased radially inwardly by springs so as to press into contact with the conductive portions 42a to 42d of the energizing rings 44a to 44d;
It consists of an energized brush mechanism equipped with 48d. Hollow rotating shaft 10 and energizing rings 44a to 44
The conductive parts 42a to 42d are placed in the center hole 1 of the hollow rotating shaft 10 at positions corresponding to the conductive parts 42a to 42d of d.
Horizontal holes 50a, 50b, 50c exposed to 0a,
50d is opened, and the aforementioned lead wire 38
a to 38d are connected to the conductive parts 42a to 42d of the current carrying ring through the horizontal holes 50a to 50d. Lead wires (not shown) are connected to the energizing brushes 48a to 48d, respectively, and the retainers 46a to 46
d and connected to the necessary equipment. Note that the rotating energizing mechanism 40 is not limited to this structure.

The centrifugal spinning device 2 is used in a pitch fiber spinning system as shown in FIG. This system consists of a melting section M and a spinning section S, and a centrifugal spinning device 2 is disposed in the spinning section S.

The melting zone M has a hopper 52 into which isotropic or mesophase solid pitch starting from coal or petroleum pitch is introduced. After charging the solid pitch, the hopper 52 expels the air inside, injects nitrogen gas, and exposes the solid pitch to the nitrogen gas.

A heating screw 54a is provided at the bottom of the hopper 52.
A screw type heating and melting device 54 having a built-in screw is connected thereto, and the heating screw 54a is rotationally driven by a motor 54b. The solid pitch put into the hopper 52 is heated by the rotation of the heating screw 54a.
While being heated and melted at a temperature of 300 to 350°C, it is sent to the outlet 54c at the tip of the screw at a constant speed.
A melting tank 56 is connected to the outlet of the screw tip, and the heated and melted pitch flows into the melting tank 56 and is collected at a certain head. A gear pump 56b driven by a motor 56a is provided at the lower part of the melting tank 56, and the melting pitch is connected to the aforementioned supply pipe 3 by this gear pump 56b.
Sent to 0. The molten pitch that has reached the supply pipe 30 is sent from there to the spinner disk 6 of the centrifugal spinning device 2.
flow inside.

The solid pitch may be melted directly in the melting tank 56 as long as it is in an inert atmosphere.
In this case, it will be a batch type.

Hopper 52 and screw type heating melting device 5
4 allows continuous melting of solid pitch.

The solid pitch is melted in the melting zone M at a temperature that does not cause thermal decomposition of the pitch.

Centrifugal spinning of molten pitch by the centrifugal spinning device 2 is carried out as follows. First, before the molten pitch flows into the spinner disk 6 from the supply pipe 30, nitrogen gas is supplied from the supply pipe 30 into the spinner disk to expel the air therein and create a nitrogen atmosphere. A current is supplied from a current supply source (not shown) through current-carrying brushes 48a, 48b of the rotating current-carrying mechanism 40 to terminals 32a, 34a and 32b, 3 connected to these brushes via lead wires 38a, 38b.
4b is supplied with current, and the sheet heating elements 12a, 12
b generates heat and heats the top wall 6a, bottom wall 6b, and side wall 6c of the spinner disk 6. The temperature of the spinning portion near the side plate 6c of the spinner disk 6 is detected by the thermocouple 36, and the current is sent from the energizing brushes 48c, 48d of the rotating energizing mechanism 40 to a control section (not shown) via lead wires 38c, 38d. The amount of current supplied to the terminals 32a to 34d is controlled, and the temperature of the spinning section near the side wall 6c of the spinner disk 6 is controlled to a constant temperature of, for example, 300 to 360°C.

After this, the molten pitch is supplied from the supply pipe 30 into the spinner disk 6, and at the same time,
The spinner disk 6 is rotated at a high speed of about 1400 to 2500 rpm by rotating the hollow rotary shaft 10 with the motor 26 via the pulleys 24, 28 and the belt 29. As a result, the molten pitch that has flowed into the spinner disk 6 reaches the spinning nozzle hole 102c of the convex nozzle structure 102 of the spinning nozzle device 100 provided on the side wall 6c, from where it is discharged to the outside by centrifugal force, and is discharged from the spinner disk 6. The fibers are formed into fibers by the air friction around them induced by the high-speed rotation of the fibers, and are spun into pitch fibers.

As described above, the side wall 6 of the spinner disk 6 is heated by the planar heating elements 12a, 12b and the thermocouple 36.
The temperature of the spinning part near c is controlled to a constant temperature of approximately 300 to 360°C, but the sheet heating elements 12a and 12b
are the top plate 6a and bottom plate 6b of the spinner disk 6.
Since the top wall 6a and the bottom wall 6 are in contact and fixed state,
b. When the temperature of the side wall 6c is about to drop, heat is instantaneously supplied from the planar heating elements 12a and 12b,
Its temperature is precisely controlled at a constant temperature of about 300-360℃. Therefore, the temperature of the spinning portion near the side wall 6c is not affected by the temperature of the melt pitch, and even if the temperature of the melt pit is kept low until it reaches the spinning nozzle hole 102c of the side wall 6c, the temperature of the spinning nozzle hole 102c
When passing through, the temperature of that part instantly changes, i.e. approximately 300 to 360℃.
The spinning nozzle hole 102c is heated to a constant temperature of
The temperature of the molten pitch passing through is precisely controlled. Therefore, within the spinner disk 6, the pitch fibers formed through the spinning nozzle hole 102c are successfully turned into fibers without causing any alteration such as foaming or phase separation of the molten pitch, and there is no variation in the fiber formation. The cross-sectional structure can also be easily controlled. This means that the spinning nozzle hole 102c
The same applies when the amount of molten pitch discharged from the molten pitch is varied or increased, and when the amount of molten pitch is increased, the productivity of pitch fibers can be increased.

Further, in the centrifugal spinning device 2, the current supply terminals 32a to 34b and the lead wires 38a to 38d for the thermocouple 36 are passed through the central hole 10a of the hollow rotating shaft 10, and then connected to the hollow rotating shaft 10 and the hollow fixed shaft 22. Since it is connected to the provided rotary current supply mechanism 40 and communicated with the outside of the hollow fixed shaft, the overall structure is extremely compact and does not require a large installation space.

As a heating means for the spinner disk 6 of the centrifugal spinning device 2, the planar heating elements 12a, 1
2b, the top wall 6a, bottom wall 6b, and side wall 6c of the spinner disk 6 may themselves be made of an electrically conductive heat generating material such as a Ni-Cr alloy, and in this case as well, the same direct heating effect and Space saving effect can be obtained.

When spinning pitch fibers using such a centrifugal spinning device 2, according to the spinning nozzle device 100 of the present invention, the operating time becomes long and the spinning nozzle hole 102c
If the spinning nozzle hole 102c is worn out or the pits attached around the exit side of the spinning nozzle hole 102c are partially oxidized or carbonized, and the spinning nozzle hole can no longer be used,
Since the convex nozzle structure 102 is removable, it is only necessary to remove it and install a new convex nozzle structure, which is extremely economical since the entire spinner disk does not have to be replaced. This also facilitates the use of spinning nozzle holes with hole diameters within a certain range, thereby reducing fluctuations in the fiber diameter of the pitch fibers being spun, which also helps improve quality. As a result of the experiment, convex nozzle structure 1
Even if 02 was replaced 15 to 30 times, it was possible to use the spinner disk 6. Therefore, the life of the spinner disk can be improved by 15 to 30 times compared to conventional spinner disks. Furthermore, if you want to change the diameter of the pitch fibers to be spun, you can simply replace the convex nozzle structure with a convex nozzle structure equipped with spinning nozzle holes of a different diameter, thus creating a new spinner disk. There is no need for this, and in this sense it is also economical.

Note that the spinning nozzle device 100 of the present invention has a convex nozzle structure even when rotated at high speed because the head 102b of the convex nozzle structure 102 is located on the inner peripheral surface 106 side of the side wall 6c of the spinner disk 6. Since the body does not come off the spinner disk 6 and is securely held there, there is no risk of it being scattered around due to centrifugal force, allowing safe operation, and special fixing such as welding or riveting is not required. Since there is no need to use any means, the replacement is easy.

Further, in the case of the spinning nozzle device 100 of the present invention according to the embodiment shown in FIG.
Since the shaft portion 102a of 02 and the mounting hole 104 are removably inserted with a light tight fit,
Since it can be installed and removed by simply pushing it in by hand or hitting it with a mallet, replacement is extremely easy. If at least one of them is tapered as in the example, replacement can be done even more easily.

Further, in the illustrated embodiment, the inner surface of the head of the convex nozzle structure has a contact surface shape that follows the inner circumferential surface 106 of the spinner disk 6, so that it is in sealing engagement with the inner circumferential surface by centrifugal force during operation. As a result, extremely good sealing performance can be obtained.

(Effects of the Invention) As is clear from the foregoing, according to the spinning nozzle device of the centrifugal spinning device for melt pitch of the present invention, the convex nozzle structure with the spinning nozzle hole opened in the axial direction, the head of which is connected to the spinner disk. By inserting the shaft part into the mounting hole formed in the side wall so that it is located on the inner circumferential surface side of the side wall of the spinner disk, it is removably attached to the side wall of the spinner disk. Pits that are worn out or attached to the spinning nozzle exit side during operation may
Even if the spinning nozzle hole becomes unusable due to oxidation or carbonization, there is no need to replace the entire spinner disk, but only the convex nozzle structure, which is extremely economical and extends the life of the spinner disk. can be improved by 15 to 30 times compared to conventional methods, and this also means that by replacing the spinner disk while the diameter of the spinning nozzle hole is within a certain range, fluctuations in the diameter of the pitch fibers being spun can be reduced. It is possible to produce pitch fibers with consistent quality in a small quantity, and even if you want to obtain pitch fibers with different fiber diameters, you can simply replace the convex nozzle structure with one with a different nozzle hole diameter. It is not necessary to replace the entire disk, and therefore, in this sense as well, economic efficiency can be greatly improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a spinning nozzle device in a pitch fiber centrifugal spinning device according to a preferred embodiment of the present invention, and FIGS. 2 and 3 are a cross-sectional view of a spinning nozzle device according to another embodiment of the present invention. 4 is a longitudinal sectional view showing the entire centrifugal spinning device including the spinning nozzle device shown in FIG. 1;
5 is an enlarged view of the left half of the spinner disk shown in FIG. 4, FIG. 6 is a bottom view of the spinner disk shown in FIG. 4, and FIG. 7 is an enlarged view of the left half of the spinner disk shown in FIG.
FIG. 1 is a schematic diagram showing the entire system consisting of a melting section and a spinning section, including the centrifugal spinning device shown in the figure. In the figure, reference numeral 2...Centrifugal spinning device, 6...Spinner disk, 6c...Side wall, 10...Rotation drive shaft, 100, 100A, 100B...Spinning nozzle device, 102, 102A...Convex nozzle structure ,
102a, 102e...Shaft portion, 102b...Head, 102c...Spinning nozzle hole, 104, 104
B...Mounting hole, 106...Inner peripheral surface.

Claims (1)

[Claims] 1. A spinner disk comprising a top wall, a bottom wall, and a side wall, and a rotational drive shaft attached to the center of the bottom wall of the spinner disk, which supplies molten pitch into the spinner disk. In a spinning nozzle device in a centrifugal spinning device for pitch fibers, which spins molten pitch into pitch fibers by rotating the spinner disk at high speed with the rotation drive shaft, the spinning nozzle device comprises a shaft portion and a head portion, and has at least one shaft in the axial direction. 1
a convex nozzle structure with four spinning nozzle holes, a plurality of attachment holes for the convex nozzle structures are formed in the side wall of the spinner disk along the circumferential direction thereof, and the convex nozzle structure by inserting the shaft into the mounting hole such that the head of the body is located on the inner peripheral surface side of the side wall of the spinner disk,
A spinning nozzle device for a centrifugal spinning machine for melt pitch, characterized in that the spinning nozzle device is removably attached to the side wall of the spinner disk. 2. A spinning nozzle device in a melt pitch centrifugal spinning device according to claim 1, wherein the shaft portion of the convex nozzle structure is at least partially inserted into the attachment hole in a light interference fit. 3. Centrifugal spinning of molten pitch according to claim 2, wherein both the shaft portion of the convex nozzle structure and the attachment hole have a constant diameter, and are in a light interference fit over almost the entire length. Spinning nozzle device in the device. 4. The shaft portion of the convex nozzle structure has a tapered shape, the mounting hole has a constant hole diameter, and the shaft portion is slightly tightened at the root portion of the shaft portion with respect to the mounting hole. A spinning nozzle device in a centrifugal spinning device for melt pitch according to claim 2, which is in a fitted state. 5. The shaft of the convex nozzle structure has a constant diameter, the mounting hole is tapered radially outward, and the shaft has a fixed diameter with respect to the mounting hole. 3. A spinning nozzle device for a centrifugal spinning device for melt pitch according to claim 2, wherein the spinning nozzle device is in a state of light interference fit at the tip end of the spinning nozzle. 6 The head of the convex nozzle structure has a shape in which its inner surface follows and contacts the inner circumferential surface of the side wall of the spinner disk around the mounting hole, and seals with the inner circumferential surface due to centrifugal force during operation. A spinning nozzle device in a melt pitch centrifugal spinning device as claimed in claim 1, adapted to engage with each other.