Microwave treatment apparatus and method for producing carbon fiber

A microwave treatment apparatus comprising:

• a vessel inside which a treatment target moves;
• a microwave irradiating unit including first and second irradiating portions that irradiate an internal portion of the vessel with microwaves;
• and
• a heat generating member that is provided inside the vessel along a movement path of the treatment target, generates heat by absorbing part of microwaves used for irradiation by the microwave irradiating unit, and transmits part of the microwaves, the heat generating member including a support member and a heating medium that is supported by the support member,
• wherein each of the first and second irradiating portions heats the treatment target from an outside through heat generation of the heating medium, and directly heats the treatment target with microwaves transmitted through the heat generating member, and
• the microwave irradiating unit controls phases of microwaves that are used for irradiation by the first and second irradiating portions, thereby performing first microwave irradiation in which microwaves used for irradiation by the first and second irradiating portions are intensified by each other at the heating medium, and second microwave irradiation in which microwaves used for irradiation by the first and second irradiating portions are intensified by each other at the treatment target, at different positions on the movement path of the treatment target.

A method for producing a carbon fiber, comprising a step of irradiating an internal portion of a vessel with microwaves, the vessel including a heat generating member therein, thereby heating a precursor fiber of a carbon fiber that moves along the heat generating member,

• wherein, in the heating step, the heat generating member including a support member and a heating medium that is supported by the support member is irradiated with microwaves from first and second irradiating portions, so that:
• the precursor fiber is heated from an outside through heat generation of the heat generating member, and the precursor fiber is directly heated with microwaves transmitted through the heat generating member;
• and
• heating is performed at different positions on the movement path of the precursor fiber.