Abstract: To perform a flame-resistant treatment on a precursor fiber strand by sending hot air to a heat treatment chamber (2) through a hot air blowing nozzle (4) in a direction parallel to a running direction of a precursor fiber strand (10). The hot air blowing from the hot air blowing nozzle (4) passes through a porous plate and a rectifying member that satisfy the following conditions (1) to (4), wherein the conditions are set as follows: (1) A/B?4.0; (2) 0.15???0.35; (3) 0?B?d?20; and (4) 80% or more of an area of one opening of the porous plate when causing facing surfaces of the porous plate and the rectifying member to overlap each other is included in one opening of the rectifying member, A indicating a hot air passage distance (mm) of the rectifying member, B indicating a horizontal maximum distance (mm) of one opening of the rectifying member, ? indicating a rate of hole area of the porous plate, and d indicating an equivalent diameter (mm) of the porous plate.

Abstract: The present invention is: a horizontal heat treatment apparatus for continuously heat-treating by moving a continuous flat workpiece to be treated (carbon-fiber-precursor fiber bundles) back and forth in the horizontal direction on multiple levels inside a heat treatment chamber, the horizontal heat treatment apparatus being characterized by being provided with a sealing chamber (4) which is continuous from the entrance (6) side of the heat treatment chamber (2) in to which the workpiece to be treated is conveyed to the exit (6?) side thereof and that is vertically delimited by partition plates making a heat transfer zone in which 2 to 4 levels of the workpiece are transferred, among which the temperature of the workpiece transferred in a lower level is higher than the temperature of the workpiece transferred in a higher level. As a result, the horizontal heat treatment apparatus completely prevents leakage of poisonous gas produced in the heat treatment chamber, and effectively prevents energy loss.

Abstract: To perform a flame-resistant treatment on a precursor fiber strand by sending hot air to a heat treatment chamber (2) through a hot air blowing nozzle (4) in a direction parallel to a running direction of a precursor fiber strand (10). The hot air blowing from the hot air blowing nozzle (4) passes through a porous plate and a rectifying member that satisfy the following conditions (1) to (4), wherein the conditions are set as follows: (1) A/B?4.0; (2) 0.15???0.35; (3) 0?B?d?20; and (4) 80% or more of an area of one opening of the porous plate when causing facing surfaces of the porous plate and the rectifying member to overlap each other is included in one opening of the rectifying member, A indicating a hot air passage distance (mm) of the rectifying member, B indicating a horizontal maximum distance (mm) of one opening of the rectifying member, ? indicating a rate of hole area of the porous plate, and d indicating an equivalent diameter (mm) of the porous plate.

Abstract: A furnace to flame-resistantly treat a precursor fiber strand by sending hot air to a heat treatment chamber through a hot air blowing nozzle in a direction parallel to a running direction of the strand is provided. The hot air passes through a porous plate and a rectifying member satisfying the following conditions: (1) A/B?4.0; (2) 0.15???0.35; (3) 0?B?d?20; and (4) 80% or more of the area of one opening of the porous plate when facing surfaces of the porous plate and the rectifying member overlap is included in one opening of the rectifying member, where A is the rectifying member hot air passage distance (mm), B is a horizontal maximum distance (mm) of one opening of the rectifying member, ? is a rate of hole area of the porous plate, and d is the porous plate equivalent diameter (mm).

Abstract: A process for producing an acrylonitrile-based polymer solution is provided with which it is possible to evenly and efficiently dissolve an acrylonitrile-based polymer in a solvent, inhibit the filter or spinning nozzle from clogging, and stably produce an acrylonitrile-based polymer solution. The process for producing an acrylonitrile-based polymer solution comprises supplying a mixture of the polymer and a solvent to the dispersion chamber of a shearing device comprising a cylinder and a rotor that rotates inside the cylinder, rotating the rotor under the following conditions to apply shear force to the mixture, and thereafter heating the obtained mixture to obtain an acrylonitrile-based polymer solution. W=(W1?W2)/M?0.12 (kWh/kg). W1, W2, and M are defined in the description. Alternatively, the conditions may be changed so that W?1.60, and the heating may be omitted.

Abstract: A furnace to flame-resistantly treat a precursor fiber strand by sending hot air to a heat treatment chamber through a hot air blowing nozzle in a direction parallel to a running direction of the strand is provided. The hot air passes through a porous plate and a rectifying member satisfying the following conditions: (1) AB?4.0; (2) 0.15???0.35; (3) 0?B?d?20; and (4) 80% or more of the area of one opening of the porous plate when facing surfaces of the porous plate and the rectifying member overlap is included in one opening of the rectifying member, where A is the rectifying member hot air passage distance (mm), B is a horizontal maximum distance (mm) of one opening of the rectifying member, ? is a rate of hole area of the porous plate, and d is the porous plate equivalent diameter (mm).

Abstract: To be provided are a heat treatment apparatus having blocking members which block gaps between the side walls of nozzle boxes provided with slit nozzles, whose size in the lengthwise direction is greater than the width of a sheet, and the side walls of a heat treatment chamber, and gas having a uniform velocity fluctuating no more than ±25% in the lengthwise direction of the slit nozzles is blown out of the slit nozzles to subject the sheet to heat treatment, resulting in little unevenness of temperature in the widthwise direction and reduced energy loss, and a heat treatment method using this heat treatment apparatus.

Abstract: To be provided are a heat treatment apparatus having blocking members which block gaps between the side walls of nozzle boxes provided with slit nozzles, whose size in the lengthwise direction is greater than the width of a sheet, and the side walls of a heat treatment chamber, and gas having a uniform velocity fluctuating no more than ±25% in the lengthwise direction of the slit nozzles is blown out of the slit nozzles to subject the sheet to heat treatment, resulting in little unevenness of temperature in the widthwise direction and reduced energy loss, and a heat treatment method using this heat treatment apparatus.

Abstract: Disclosed are a belt type continuous plate manufacturing apparatus including two endless belts 11, 11? with their facing belt surfaces running toward the same direction at the same speed, and a gasket 7 sandwiched by belt surfaces at their both side edge portions, in which a polymerizable raw material is fed into a space surrounded by the facing belt surfaces and the gasket from its one end, and solidified together with running of the belts in a heating zone, and a plate polymer is taken out from the other end, wherein a plurality of upper and lower roll pairs 4, 4? each composed of an upper roll 4 and a lower roll 4? and having axes orthogonally grossing the belt running direction are placed along the belt running direction as a mechanism of holding the belt surfaces of the endless belts 1, 1? in the heating zone, and the outer diameter D of the roll body portion of the upper and lower roll pair is in the range of 100 mm to 500 mm; and a method of producing a plate polymer using this apparatus.