Gas supply blowout nozzle and method of producing flame-proofed fiber and carbon fiber

Patent metadata

Field	Value
Publication number	US-2016160395-A1
Application number	US-201414907001-A
Country	US
Kind code	A1
Filing date	Jul 23, 2014
Priority date	Jul 23, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

The nozzle body of the gas supply blowout nozzle ( 11 ) includes an inclined plate ( 13 ) guiding a gas flowing straightly from a gas inlet port to a rectification board ( 12 ), which is connected with the nozzle body. The rectification board ( 12 ) rectifies the flow of the gas guided by the inclined plate ( 13 ) so that the gas blows out perpendicular or parallel to a yarn from a gas outlet port. A gas guiding zone formed between the inclined plate ( 13 ) and the rectification board ( 12 ) includes one or more guide plates ( 14 ) which divide the gas supplied from the gas inlet port ( 11 a ) of the gas supply blowout nozzle ( 11 ) into two or more streams. In each gas passage formed at least one of between the inclined plate ( 13 ) and the guide plate ( 14 ) or between the guide plates ( 14 ), an upstream passage width W 1 and any downstream passage width W 2 thereof satisfy the relation of W 1 ≧W 2. The opening area A of the gas inlet port ( 12 a ) and the opening area B of the gas inlet of the rectification board ( 12 ) may satisfy the relation of A≦B. By means of said configuration, the wind speed in the heat treatment furnace is made uniform, the non-uniformity in the quality of the product caused by the non-uniformity of the wind speed is eliminated, longtime stable production is enabled, production efficiency is increased, and running costs are decreased.

First claim

1 . A gas supply blowout nozzle, comprising:
a nozzle body comprising an inclined plate adapted to guide a gas flowing straightly from a gas inlet port to a rectification board; and the rectification board which is adapted to rectify the flow of the gas guided by the inclined plate so that the gas blows out toward a yarn from a gas outlet port, wherein a gas introduction direction in the gas supply blowout nozzle is different from a gas blowing out direction, wherein a gas guiding zone is formed between the inclined plate and the rectification board, wherein the gas guiding zone comprises a guide plate which is disposed in a space between the gas inlet port and the rectification board and which divides the gas supplied from the gas inlet port of the gas supply blowout nozzle into two or more streams so that the gas is guided toward the rectification board, and wherein in each gas passage formed, at least one of between the inclined plate and the guide plate or between the guide plates, an upstream passage width W 1 perpendicular to a gas flowing direction inside the gas passage and any downstream passage width W 2 thereof satisfy the following relation
W1≧W2   (1).

2 . (canceled)

3 . The gas supply blowout nozzle according to claim 1 , wherein the rectification board is directly attached to the nozzle body.

4 . The gas supply blowout nozzle according to claim 1 , wherein an opening area A of the gas inlet port and an opening area B of the gas inlet of the rectification board satisfy the relation of A≦B.

5 . The gas supply blowout nozzle according to claim 1 , wherein in the gas guiding zone, the inclined plate and one of the guide plates are disposed in parallel, and the guide plates are disposed in parallel.

6 . The gas supply blowout nozzle according to claim 1 , wherein the rectification board is disposed so that the gas rectified with the rectification board blows parallel to a yarn traveling direction.

7 . The gas supply blowout nozzle according to claim 1 , wherein the rectification board is disposed so that the gas rectified with the rectification board blows in a direction perpendicular to a yarn traveling direction.

8 . The gas supply blowout nozzle according to claim 1 , wherein the gas guiding zone is formed in a tapered shape from the gas inlet port to the opposite side surface by the inclined plate, and the gas guiding zone comprises one or more guide plates separately guiding the gas passage toward the rectification board.

9 . The gas supply blowout nozzle according to claim 1 ,
wherein straightening plates are disposed in the rectification board so as to be parallel in the gas blowing direction, and the following relations (2) and (3) are satisfied
L/P≧ 4.0   (2)

t/P≦ 0.2   (3)

wherein P indicates a pitch between the straightening plates, L indicates a length of each straightening plate, and t indicates a thickness of each straightening plate.

10 . The gas supply blowout nozzle according to claim 1 ,
wherein one or more guide plates are disposed inside the gas guiding zone so as to guide the gas flowing from the gas inlet port toward the gas inlet of the rectification board, and wherein a distance to the upstream end of the guide plate adjacent to the inclined plate from the inclined plate, and each distance between upstream ends of the guide plates adjacent with each other are smaller than 580 mm.

11 . The gas supply blowout nozzle according to claim 1 , wherein an arrangement angle of one of the guide plates is changeable.

12 . The gas supply blowout nozzle according to claim 1 ,
wherein the gas inlet of the rectification board is disposed inside the nozzle body, and wherein a length of straightening plates in a portion of the rectification board near the gas inlet port of the nozzle body is made shorter than a length of straightening plates in the other portion of the rectification board by shortening the straightening plates on the side of the gas inlet of the rectification board.

13 . The gas supply blowout nozzle according to claim 12 , wherein the length of the straightening plates is sequentially shortened toward the gas inlet port so that a tapered portion of the rectification board is formed.

14 . The gas supply blowout nozzle according to claim 1 , further comprising:
a stream separation plate which is provided near the gas outlet port in the gas inlet port and on a side surface of the nozzle body near the rectification board, wherein an area Sh of the stream separation plate projected toward the gas inlet port is 1/10 or less and 1/50 or more of an opening area Si of the gas inlet port.

15 . The gas supply blowout nozzle according to claim 1 ,
wherein an end straight portion which guides a gas stream to between the straightening plates is provided in a narrow end of the nozzle body, and a length x of the end straight portion and a width W 0 of the gas inlet port satisfy the following relation (4)
x/W 0≦0.06   (4).

16 . A method for producing a flame-proofed fiber comprising performing a flame-proofing treatment on a carbon-fiber precursor fiber bundle by using a heat treatment furnace comprising the gas supply blowout nozzle according to claim 1 .

17 . A method for producing a carbon fiber satisfying the following (a) to (c):
(a) introducing a carbon-fiber precursor fiber bundle widen into a sheet shape into a flame-proofing furnace comprising the gas supply blowout nozzle according to claim 1 , so as to perform a flame-proofing treatment thereon in a temperature range of 200° C. to 300° C. and introducing the flame-proofed fiber obtained by the flame-proofing treatment into a carbonizing furnace so as to perform a carbonizing treatment thereon in a temperature range of 500° C. to 2500° C.; (b) blowing hot air blown out from the gas supply blowout nozzle toward the carbon-fiber precursor fiber bundle horizontally traveling through the flame-proofing furnace; and (c) in the gas supply blowout nozzle, satisfying the following conditions i and ii: i. a difference in pressure between the gas immediately before introduced into the gas supply blowout nozzle and the gas immediately after blown out from the gas supply blowout nozzle is 160 Pa or less; and ii. a non-uniformity in a wind speed of the gas blown out from the gas supply blowout nozzle is 35% or less, wherein the non-uniformity in the wind speed is obtained as follows: the wind speed is measured at five points in a direction perpendicular to a yarn traveling direction downstream 2 m from an end surface of the gas outlet port of the gas supply blowout nozzle; and the non-uniformity in the wind speed is calculated by the following formula (5):
non-uniformity in the wind speed={(maximum value−minimum value)of wind speed×100}/{(average value of wind speed at five positions)×2}  (5).

18 . The method according to claim 17 , further satisfying (d) to (f):
(d) in the gas supply blowout nozzle, satisfying the following conditions iii to vii: iii. the gas supply blowout nozzle comprises a nozzle body and a rectification board, wherein the nozzle body comprises an inclined plate guiding a gas flowing straightly from a gas inlet port to the rectification board, and the rectification board is directly attached to the nozzle body so as to rectify the flow of the gas guided by the inclined plate and to blow the gas toward a yarn; iv. a gas guiding zone is formed between the inclined plate and the rectification board and one or more guide plates are disposed in the gas guiding zone; v. the passage width

Assignees

• Mitsubishi Rayon Co

Inventors

• Arai Risa
• Kaji Satoshi
• Kawamura Atsushi

Classifications

• F26B21/50

  Ducting arrangements from the source of air or other gases to the materials or objects being dried · CPC title

• D02J13/00

  Heating or cooling the yarn, thread, cord, rope, or the like, not specific to any one of the processes provided for in this subclass (heating, cooling or drying during spinning or twisting D01H; drying of yarns or the like, in general F26B) · CPC title

• F27B9/28

  for treating continuous lengths of work · CPC title

• B05B1/14

  with multiple outlet openings (B05B1/02, B05B1/26 take precedence); with strainers in or outside the outlet opening · CPC title

• B05B1/3402

  to avoid or reduce turbulence, e.g. with fluid flow straightening means · CPC title