The present invention provides an exhaust gas treatment method and an exhaust gas treatment device which prevent the generation of NO.sub.X, and treat a first exhaust gas and a second exhaust gas with a small amount of fuel, and the exhaust gas treatment method comprises a first combustion step which treats a first exhaust gas discharged from a carbonization furnace for carbonizing a fibrous substance in an inert atmosphere and a graphitization furnace for graphitizing a fibrous substance in an inert atmosphere and a second combustion step of treating a second exhaust gas discharged from a flameproofing furnace for flameproofing a fibrous substance in air atmosphere, wherein the first exhaust gas is combusted at an oxygen ratio of 0.8 or less in the first combustion step, and the second exhaust gas is combusted in the second combustion step using sensible heat and latent heat of a third exhaust gas discharged in the first combustion step.

The present invention provides a microwave heating unit formed by comprising: a furnace body in which a fiber inlet and a fiber outlet are formed in a tube wall of a waveguide; and a microwave oscillator which guides microwaves into the waveguide. The microwave heating unit is characterized in that: continuous fibers to be heated are configured to have an inclination of an angle ?? with respect to the tube shaft of the waveguide and to travel therein; the angle ?? is 0.

A method of producing carbon fibers includes the step of providing polyacrylonitrile precursor polymer fiber filaments. The polyacrylonitrile precursor filaments include from 87-97 mole % acrylonitrile, and less than 0.5 mole % of accelerant functional groups. The filaments are no more than 3 deniers per filament. The polyacrylonitrile precursor fiber filaments can be arranged into tows of at least 150,000 deniers per inch width. The arranged polyacrylonitrile precursor fiber tows are stabilized by heating the tows in at least one oxidation zone containing oxygen gas and maintained at a first temperature T.sub.1 while stretching the tows at least 10% to yield a stabilized precursor fiber tow. The stabilized precursor fiber tows are carbonized by passing the stabilized precursor fiber tows through a carbonization zone. Carbon fibers produced by the process are also disclosed.

A fiber pre-oxidization device of the present disclosure basically has a transmitting unit and a microwave processing unit. The microwave processing unit is installed with at least one magnetron and a gas supplying unit, wherein the magnetron is disposed at an oven body of the transmitting unit, and the gas supplying unit is connected to the oven body. By focusing the microwave, an ultra-fast pre-oxidization process is applied on a fiber yarn bunch which continuously passes the oven body, and thus the fiber yarn bunch is processed to form an oxidation fiber yarn bunch. Thus, not only an oxidization time of an oxidation fiber can be reduced, but also the shell-core structure of the oxidation fiber can be reduced. Even, the oxidation fiber has no obvious shell-core. Accordingly, relatively positive and reliable means for increasing the performance of carbon fiber are provided.

A heating device for producing carbon fibers from a thread-shaped fiber starting material, wherein the heating device has a central tubular induction heating element through which the fiber starting material is moved. The tubular induction heating element is surrounded by thermal insulation. At least one mid- to high-frequency induction coil is provided outside the thermal insulation, and an inert gas flows through the central induction heating element, in particular, for carbonizing and/or graphitizing the fiber starting material. For energy optimization, a first and a second tube element is provided on the outer side of the thermal insulation. The elements are made of material that is transparent to the induction field of the mid- to high-frequency induction coil and are spaced apart from one another by an annular gap through which the inert gas flows.

A method of manufacturing a stabilized fiber bundle is described, which includes subjecting an acrylic fiber bundle aligned, to a heat treatment in an oxidizing atmosphere, with the acrylic fiber bundle being turned around by a guide roller placed on each of both ends outside a hot air heating-type oxidation oven, wherein an air velocity Vm of first hot air sent through a supply nozzle(s) disposed above and/or under a fiber bundle travelled in the oxidation oven, in a substantially horizontal direction to a travelling direction of the fiber bundle, and an air velocity Vf of second hot air flowing in a fiber bundle passing a flow channel in which the fiber bundle is travelled that satisfies expression 1)
0.2?Vf/Vm?2.01)
to produce a high-quality stabilized fiber bundle and a high-quality carbon fiber bundle at high efficiencies without any process troubles.

The invention describes an energy-efficient method for simultaneous generation of carbon fibers and electricity by means of bundled sunlight for the CO2-neutral production of pressure- and tensile-stable building materials, which are able to bind anthropogenic carbon, in case the carbon fibers are produced from vegetable oils. Through the oil generation by photosynthesis, carbon dioxide is being split off and carbon is being bound in the oil, as well as oxygen is being released.

Due to the fact that the production energy has a purely regenerative character, it is ensured that in the short-term not only carbon neutrality can not be introduced, but carbon is permanently withdrawn from the climate system of atmosphere and ocean.

The energy efficiency is based on the principle to heat the carbon fiber to be produced directly up with bundled sunlight, which is made possible by the fact that the original PAN fiber becomes dark during the oxidation and pyrolysis process and finally becomes an almost ideal black body.

The resulting heat is used subsequently or simultaneously to the material production of the fiber for the production of electricity, which corresponds to the classical combined heat and power principle, in order to additionally increase the efficiency in carbon fiber production already increased by this process, by delivery of energy in form of high valuable electricity.

The fibers are used on demand in combination with mineral material as a substitute for CO2intensive construction materials such as steel concrete, steel and aluminum.

After use the carbon fibers are separated from the stone by peeling and stored away without large energy expenditure in underground or above-ground camps without difficulty, whereby the carbon bound in the carbon fiber remains permanently bound.

Thus, the economy is becoming the driving force behind advancing decarbonization with a negative algebraic sign.

An apparatus is disclosed for electromagnetically and thermally treating polymeric materials, including PAN and other carbon fiber precursors at large scale at atmospheric pressure, while measuring the temperature in the closed environment of the process chamber. The apparatus is designed for continuous processing, and to be compatible with other stages of existing carbon fiber production lines. It provides direct electromagnetic coupling to the fiber tow(s) in a resonant cavity of one or more microwave waveguide launchers and also provides direct radiative or IR heating from susceptor plates located on the opposite side of the tow from the waveguide opening for processing a band of multiple tows of fiber. It produces high-temperature-carbonized (HTC) fiber with shorter residence time and higher density compared to the conventional process. Its design is inherently scalable to larger production.

There is provided an oxidation heat treatment oven including a heat treatment chamber configured to heat-treat a fiber bundle that is an aligned acrylic fiber bundle in an oxidizing atmosphere to form an oxidized fiber bundle; a slit-shaped opening configured to take the fiber bundle in and out of the heat treatment chamber; guide rollers installed at both ends of the heat treatment chamber and configured to turn the fiber bundle back; a hot air supply nozzle that has a longitudinal axis along the width of the fiber bundle traveling and that blows out hot air, in a direction substantially parallel to a traveling direction of the fiber bundle, above and/or below the fiber bundle traveling in the heat treatment chamber; and a suction nozzle configured to suck the hot air blown out from the hot air supply nozzle, in which the hot air supply nozzle satisfies disclosed conditions (1) to (3).

A carbon fiber manufacturing method includes joining first and second target fiber bundles with a joining fiber bundle, and carbonizing the joined bundles by feeding them through one or more carbonization furnaces. The joining includes forming an overlap between a first end of the joining fiber bundle and a second end of the first target fiber bundle and jetting a fluid to the overlap to form a first entangled portion, and forming an overlap between a second end of the joining fiber bundle and a first end of the second target fiber bundle and jetting a fluid to the overlap to form a second entangled portion. When the first and second entangled portions each have two or more entangling points with a tensile strength not less than 400 N, the relationship defined by the inequality is satisfied: 40>{L2/(L2A)}(S+13), where L2 is a length (mm) of an elongation section inside a first carbonization furnace upstream in a feeding direction of the fiber bundles, A is a maximum distance (mm) between an entangling point in the first entangled portion and an entangling point in the second entangled portion, and S is an elongation (%) of the joined fiber bundles fed through the carbonization furnace.