JPH0420495Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an improvement in a heat treatment reactor used to produce pitch, which is a raw material for high-performance pitch-based carbon fiber.

[Conventional technology]

In recent years, in response to technological advances in the aircraft industry, automobile industry, and various other technical fields, or from the viewpoint of energy and resource conservation, high strength and high There is a need for the development of pitch-based carbon fibers with high elastic modulus and high performance. Such pitch-based carbon fibers are produced by heating the raw material pitch to perform a dealkylation reaction and a condensation cyclization reaction to produce pitch containing a large amount of mesophase in a liquid crystal state, and after spinning this pitch,
It is manufactured by subjecting this pitch fiber to an infusible treatment to obtain an infusible fiber, which is then further subjected to carbonization and graphitization treatment.

By the way, as a method for producing pitchi containing mesophase, which is the raw material for the pitch carbon fiber,
Several methods have been proposed. However, these methods require a long reaction time and complicated steps, the softening point of the pitch increases, making spinning difficult, and suppressing the softening point of the pitch results in non-uniformity. There were some problems.

For this reason, a method disclosed in Japanese Patent Application Laid-Open No. 55-99646 has been proposed as a method for manufacturing the pitch. This method uses heavy oil, tar, or pitch as a starting material, which is placed in a reaction tank and subjected to thermal decomposition and polycondensation at a temperature of approximately 380°C while being stirred and mixed by an internal stirring blade. After adjusting the mesophase concentration to 20-80%,
The polycondensate is allowed to stand still while being maintained at 400°C or below,
This is a method in which high-density mesophase pitches are allowed to settle in the lower layer of the reaction tank, allowed to grow and mature, and then accumulated, and then separated and taken out from the upper layer of the reaction tank, which contains a large amount of non-mesophase pitches (metaphases). .

[The problem that the idea aims to solve]

However, in the above method, when the starting materials such as pitch are thermally decomposed and polycondensed in the reaction tank, they are simply stirred and mixed using stirring blades placed in the reaction tank, so pitch and coke are deposited on the inner wall of the reaction tank. This causes precipitation, so-called coking. When such coking substances are formed on the inner wall of the reaction tank, the following problems occur.

The volume of the reaction tank decreases, making it impossible to maintain the predetermined reaction time.

When the coking material becomes large, it obstructs stirring and mixing in the reaction tank, further promotes the formation of the coking material, and makes it difficult to detect the reactant.

The formation of coking reduces the efficiency of heat transfer from the heat source located outside the reactor to the pitch inside the reactor.

Due to the formation of caulking materials, thermometers, liquid level gauges, etc. tend to give incorrect readings, making operation impossible.

The present invention was devised to solve the above-mentioned conventional problems, and it not only makes it possible to obtain a pitch containing a large amount of mesophase with a relatively low softening point, but also prevents coking during polycondensation and is effective against starting materials. It is an object of the present invention to provide a heat treatment reactor for producing pitches that can obtain the pitches in high yield.

[Means to solve the problem]

The present invention consists of a horizontal reactor main body, a plurality of rotating shafts arranged parallel to each other in the length direction of the main body and rotating at the same speed, and a structure in which the side surfaces of these rotating shafts are in close contact with each other. It consists of a plurality of stirring plates that are pivoted and arranged so as to coincide with each other in the plane direction between the respective rotating shafts. Stirring plates that are arranged eccentrically so as to draw a spiral trajectory in the direction of the rotation axis with respect to the axis, and that coincide with each other in the plane direction, have their centers in the same direction and at the same distance from the axis of the rotation axis. The reactor body is eccentrically arranged so that the circumferential surfaces thereof are arranged with a slight gap or in contact with each other, and the reactor body is arranged such that the outermost orbit is equal to or This is a heat treatment reactor for pitch production, characterized by having a slightly larger cross-sectional shape.

[Effect]

According to the heat treatment reactor for thermal decomposition and polycondensation of the present invention, self-cleaning is performed between the stirring plates and between the stirring plate and the reactor body, so the formation of the above-mentioned coking substances can be prevented, and the thermal decomposition and polycondensation It is possible to speed up the polycondensation reaction and improve thermal efficiency.

[Example of idea]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

1 in the figure is a heat treatment reactor. Pitch subjected to thermal decomposition and polycondensation reactions in this heat treatment reactor 1 is supplied to the next step through a pipe 4a.

The heat treatment reactor 1 has a structure shown in FIGS. 2 to 5. That is, 11 in the figure is a cylindrical body whose cross section is equal to the outermost orbit drawn by the rotation of the stirring plate group described later arranged inside as shown in FIGS. 4 and 5, and has a shape in which two circles are connected. This is the reactor body. An inlet 12 and an outlet 13 of the pitch are provided at the upper left end and lower right end of the main body 11, respectively. An oval cylindrical jacket 14 is disposed around the outer periphery of the main body 11, and an inlet 15 and an outlet 16 for the heat medium are provided at the upper left end and lower right end of the jacket 14, respectively. The main body 1
A plurality of, for example two, rotating shafts 17 and 18 that rotate at the same speed pass through the lengthwise direction of the shaft 1 in parallel with each other. These rotating shafts 17 and 18 are supported by bearings 19 to 22 provided on both side walls of the main body 11. Each of the rotating shafts 17 and 18 includes
A plurality of disk-shaped stirring plates 23..., 24... are arranged so that their side surfaces are in contact with each other, and each rotating shaft 1
7 and 18 are pivoted so that they coincide in the plane direction. The stirring plates 23..., 24... which are pivotally attached to each of the rotating shafts 17, 18 have their centers oriented in the direction of the rotating shaft with respect to the axes of the rotating shafts 17, 18, as shown in FIGS. 2 to 5. They are arranged eccentrically so as to draw a spiral trajectory. Specifically, Figures 4 and 5
As shown in the figure, between adjacent stirring plates 23, 23 of the same rotating shaft (for example 17), their centers A ₁ ,
A ₂ is eccentrically arranged at the same distance from the axis O of the rotating shaft 17 and offset from each other by a circumferential angle of 60°. In addition, the stirring plates 23 and 24 that coincide with each other in the plane direction between the rotating shafts 17 and 18 have their centers A ₁ and B ₁ and the axes O and O of the rotating shafts 17 and 18, as shown in FIG. In relation to P, they are eccentrically arranged in the same direction and at the same distance, and are arranged so that their circumferential surfaces are in contact with each other. In other words, when the rotating shafts 17, 18 are rotated at the same speed by a drive mechanism (not shown), the stirring plate group consisting of the plurality of stirring plates 23..., 24... attached to the shafts 17, 18 is at the outermost end. The orbits rotate in the shape of two connected circles, contact each other, and are configured so that automatic movement is not hindered.

Next, the operation of the heat treatment reactor for pitch production described above will be explained.

First, a predetermined amount of pitch, which is a starting material, is supplied from the inlet 12 into the reactor main body 11 of the heat treatment reactor 1, and a heat medium at a predetermined temperature is supplied from the heat medium inlet 15 to raise the temperature inside the main body 11, for example, to 450. When the rotating shafts 17 and 18 are rotated at the same speed and in the same direction with the temperature set at Since the stirring plates 23..., 24... are eccentric to the axes of the rotating shafts 17, 18 so as to draw a spiral trajectory in the direction, the stirring plates 23..., 24... form an intermittent screw, and the main body A strong feeding action occurs on the pitches fed into 11. Due to this action, the pitches in the main body 11 are moved toward the outlet 13 on the opposite side from the pitch inlet 12 while being stirred by the stirring plates 23..., 24..., during which time the pitches undergo thermal decomposition and polycondensation, and mesophase is produced. It is produced and sent to the next process through the pipe 4a.

Therefore, the heat treatment reactor for pitch production of the present invention has the following effects.

When the stirring plate group consisting of stirring plates 23..., 24... in the reactor main body 11 of the heat treatment reactor 1 that performs thermal decomposition and polycondensation is rotated, the stirring plates 23..., 2...
4 and between the stirring plates 23..., 24... and the main body 11, these members are self-cleaned, and the stirring plates 23..., 24... are in contact with each other.
..., 24... It is possible to prevent the above-mentioned caulking from being generated on the surface or the inner surface of the main body 11. the result,
The thermal decomposition of pitch and the polycondensation reaction in the heat treatment reactor 1 can be accelerated, and the thermal efficiency can be improved.

In the above embodiment, two rotating shafts constituting the heat treatment reactor were provided passing through the inside of the container, but three or more may be provided.

In the above embodiment, the stirring plates, which are respectively attached to the rotating shafts, are arranged so as to be in contact with each other, but they may be arranged with a slight gap between them.

In the above embodiment, the shape of the container is equal to the rotation orbit of the stirring plate group consisting of the stirring plates mounted on each rotating shaft, but the shape may be slightly larger than the rotation orbit.

[Effect of idea]

As detailed above, according to the present invention, it is possible to obtain a pitch that contains a large amount of mesophase with a relatively low softening point and can produce high-performance pitch carbon fiber, as well as prevent coking during polycondensation. It is possible to provide a heat treatment reactor for producing pitches that can obtain pitches at a high yield based on starting materials.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a heat treatment reactor for pitch production showing an embodiment of the present invention, Fig. 2 is a partially cutaway side view showing the reactor of Fig. 1, and Fig. 3 is a diagram of the -
4 is a sectional view taken along the - line in FIG. 2, and FIG. 5 is a sectional view taken along the - line in FIG. 2. 1... Heat treatment reactor, 11... Reactor main body, 1
2... Pituchi entrance, 13... Pituchi exit, 14...
... Jacket, 17, 18 ... Rotating shaft, 23, 2
4... Stirring plate.

Claims (1)

[Scope of utility model registration request] a horizontally placed reactor body; a plurality of rotating shafts arranged parallel to each other in the length direction of the main body and rotating at the same speed; and the rotating shafts are pivoted to the rotating shafts so that the side surfaces thereof are in close contact with each other, and a plurality of stirring plates arranged so as to coincide with each other in the plane direction between the respective rotating shafts, and the plurality of stirring plates pivotally attached to the respective rotating shafts have their centers relative to the axis of the rotating shafts. Stirring plates that are arranged eccentrically so as to draw a spiral trajectory in the direction of the rotation axis and coincide with each other in the plane direction have their centers oriented in the same direction with respect to the axis of the rotation axis.
The reactor body is eccentrically spaced at the same distance, and its peripheral surfaces are arranged with a slight gap or in contact with each other, and the reactor body has an outermost trajectory drawn by the rotation of a group of stirring plates disposed inside the reactor body. 1. A heat treatment reactor for pitch production, characterized in that it has a cross-sectional shape equal to or slightly larger than .