JPH11349310A - Furnace for producing carbon black and production of carbon black using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat resistance at high temperatures and shape retention and efficiently produce a carbon black having a small particle diameter by using a refractory subjected to stamping execution in at least a part of a furnace wall. SOLUTION: A furnace having at least a furnace wall composed of a stamping material is used as the furnace for producing a carbon black. All or a part of the furnace wall preferably brought into contact with a high-temperature gas stream is a refractory subjected to a stamping execution. The lining of the furnace wall is subjected to stamping processing with a high-melting refractory, e.g. magnesia, zirconia or alumina. In the stamping material, the magnesia having a high melting point is suitable. Groves (score lines) having a prescribed depth (5-10 mm) can uniformly be formed in the stamping material to evenly regulate positions for cracking without crazing the refractory subjected to the stamping execution. The thickness of the stamping material is preferably about 30-50 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of carbon black, and more particularly to a carbon black production furnace which can be suitably used for increasing the combustion gas temperature to produce particularly small particle size carbon black with high productivity.

[0002]

2. Description of the Related Art Conventionally, as a method for producing carbon black, high-temperature combustion gas obtained by burning fuel hydrocarbons in a production furnace constituted by using a refractory material such as alumina brick or castable is used. BACKGROUND ART A furnace type production method using a furnace type production furnace in which a raw material hydrocarbon is introduced to generate carbon black is widely known.

[0003]

In such a furnace type production furnace, when the reaction temperature is raised to improve the quality and productivity of carbon black, the refractory temperature and spalling resistance of the production furnace are reduced. Due to limitations, reaction conditions have been limited. That is, since an alumina-based (high-alumina or ultra-high-alumina) refractory material is used as a lining refractory material at the highest temperature portion, when the refractory material is brought into contact with a high-temperature gas flow having a refractory temperature (about 1800 ° C.) or higher. Has a problem that the operation cannot be performed due to phenomena such as melting and falling off of refractories due to spalling in a short period of time.

[0004] On the other hand, refractories such as magnesia are conventionally known as ultra-high temperature refractories. Of these, magnesia has a high melting point of 2800 ° C. and can withstand very high temperatures, but the design of the furnace structure is very difficult because of its large coefficient of thermal expansion and poorer spalling resistance than conventional refractories. At present, it is not practically used as an industrial furnace. Therefore, when it is attempted to use the carbon black furnace, the required properties such as spalling resistance and heat resistance are insufficient, so that it is severely damaged and practically difficult. To address such problems with ultra-high temperature refractories, a method such as adding various additives to improve spalling resistance using magnesia or zirconia as a base material can be considered. In addition to lowering the fire resistance, it has been found that the properties required for carbon black production furnaces have not yet been sufficiently maintained, such as the spattering resistance itself being reduced due to the scattering of additives in long-term operation. It has been clarified by the inventors' studies.

[0005] Further, it is conceivable to construct a furnace by dividing bricks made of ultra-high-temperature refractories such as high-purity magnesia and zirconia into small pieces so as to minimize the amount of thermal stress generated. With the structure, the auction of the bricks cannot be taken so much that the life of the furnace is shortened due to the falling off of the bricks, etc., and the work and economic burdens at the time of building and repairing the furnace are large, so that practical use is difficult. The present invention has been made to solve the above problems, and when introducing a raw material hydrocarbon into a high-temperature gas stream to generate carbon black, it is possible to increase the temperature of the raw material oil introduction region, The present invention is to provide a carbon black production furnace made of a furnace material having excellent heat resistance and shape maintenance properties.

[0006]

Means for Solving the Problems In order to achieve the above object, the present inventors have made intensive studies. As a result, it has been found that the above problem can be solved by using a refractory material stamped on at least a part of carbon black, and the present invention has been achieved. That is, in the present invention, when carbon black is produced by introducing a raw material hydrocarbon into a high-temperature gas stream, at least a part of a furnace wall is formed of a stamp material, and carbon black is produced in such a production furnace. A method for producing carbon black, characterized by performing a reaction. In addition, the stamp material here refers to a single high melting point refractory such as magnesia, zirconia, and alumina, or a dry powder material obtained by mixing a binder with these materials. Stamping refers to the use of a stamp material such as an air tool or a vibrator. A construction method that uses tools to solidify.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The method for producing carbon black of the present invention is for producing carbon black by introducing a raw material hydrocarbon into a high-temperature gas stream. Various methods known in the art can be employed for the method of generating the high-temperature gas stream and the selection of the raw material hydrocarbon. That is, a first reaction zone in which a high-temperature gas flow is formed by a combustible gas such as fuel and oxygen, and a second reaction zone which is provided subsequently thereto and in which a raw material hydrocarbon serving as a raw material of carbon black is introduced to generate carbon black. The carbon black can be suitably manufactured by a so-called furnace method in which carbon black is manufactured in a carbon black manufacturing furnace having a third reaction zone, which is installed subsequently and where the carbon black generation reaction is stopped by rapid cooling.

Here, in the present invention, the production furnace is
It is assumed that at least a part of the furnace wall is made of a stamp material. Preferably, all or part of the furnace wall portion of the furnace wall that comes into contact with the high-temperature gas flow is a stamped refractory. Examples of a form in which a corresponding portion of the furnace wall is stamped to form a refractory material include stamping the inside of the furnace wall with a high melting point refractory stamp material such as magnesia, zirconia, or alumina. It is preferable that the stamp material contains at least one of magnesia, zirconia and alumina as a main component. Among them, the magnesia stamp material having a high melting point withstands the highest temperature and is suitable for a carbon black high-temperature production furnace. In addition, a magnesia-chromium-based refractory material such as a refractory for magcro and a refractory for black mag may be used as the stamp material in addition to the commercially available stamp materials mentioned above. In the production of carbon black, durability under severe conditions of contact with a high-temperature and ultra-high-speed gas is required. In addition, since various parameters of the furnace shape play an important role in controlling various properties of the obtained carbon black, the carbon black production furnace is processed into a complicated and precise shape.

As a result of diligent studies by the present inventors, stamping using such a stamp material is excellent in both shape retention and heat resistance under carbon black production conditions at an ultra-high temperature. It has been found that this is an extremely excellent furnace material and construction method that satisfies the required characteristics as a furnace material and construction method for a carbon black production furnace capable of obtaining carbon black having a small particle size.

[0010] The refractory used as a stamp material has a higher purity in terms of heat resistance, but has a lower spalling resistance. However, in the manufacturing furnace of the present invention, even if a crack is generated in the stamp material due to spalling, the stamp material does not fall off due to the roughness of the fractured surface. Therefore, stamping using a stamp material of high purity is suitable to satisfy the required characteristics.
In general, only the inner wall surface of the stamp material is sintered when the temperature of the furnace is raised, and the stamp material is used without being sintered on the back surface.
It is known that this stamping is used for an induction furnace for melting metal. This is because the flow of the molten material can be stopped by the unsintered powder stamp material on the back surface even if the sintered stamp material layer on the surface cracks due to thermal expansion. However, when the working temperature exceeds about 1800 ° C., the width and depth of the cracks in the stamp material become large, the voids extend to the unsintered stamp material on the back surface, and the melt flows out of the furnace. Is limited to 1800 ° C. or less. On the other hand, in the carbon black production furnace, since no melt is generated, the back surface may be sintered. When the stamp material is sintered to the back surface, cracks are generated in the surface direction of the construction layer at a certain depth with cracks in the thickness direction, so the construction thickness is 35 mm
When the diameter is set to 50 mm, the stamp material is less likely to fall off, and the shape maintaining characteristics are enhanced. If the construction thickness is smaller than 35 mm, the auction area of the broken stamp material is reduced, and the possibility of falling off is increased.

Further, grooves (score lines) are formed in the stamp material in advance at a predetermined depth (for example, about 5 to 10 mm).
If the cracks are substantially evenly placed, the positions where the cracks are formed can be evenly defined, and the refractory material subjected to stamping does not become small cracks, and the shape retention is further improved. Alternatively, 300 to 400 mm x 300 to 40 at a depth of 2 to 5 m / m on the inner wall of the furnace.
It is more preferable to insert a score line in a square of 0 mm. When the entire furnace is stamped with a high thermal conductivity refractory such as magnesia, the layer thickness becomes extremely large and the furnace itself becomes very large, which is not economical. Therefore, if the outside of the stamping is lined with a refractory material having a low thermal conductivity such as a heat insulating board or a heat insulating brick, the furnace itself can be made compact.

When magnesia stamping is applied to the lining of the furnace wall and a refractory such as high alumina brick is applied to the next layer, magnesia reacts with alumina to form a low melting point compound, and the fire resistance of the magnesia stamp is increased. In order to lower the boundary temperature, the boundary temperature between these layers is set to 1500 ° C. or lower, or a refractory layer of magcro brick is provided as the next layer of the magnesia stamp material, and the boundary temperature between the magcro layer and the high alumina brick layer is set to 1500 ° C. or lower. Is preferred. The stamp material application position can be used for the entire furnace, but from the part where the raw material hydrocarbons are introduced in the second reaction zone to the third reaction zone, the gas temperature decreases due to the progress of the thermal decomposition reaction of the raw material hydrocarbons and the reduction occurs. Because of the atmosphere, the inner wall of the furnace in this portion can be sufficiently covered with a refractory lining such as a conventional high alumina brick.

[0013]

Next, the present invention will be described with reference to examples. In addition, the chemical composition% of the refractory material indicates% by weight. Example 1 (1) Furnace Shape A first reaction zone having an inner diameter of 500 mm and a length of 1400 mm, in which a high-temperature combustion gas flow of 2200 ° C. is formed by a burner for mixing and burning oxygen-enriched air and gaseous fuel LPG,
A second reaction zone, which is provided in the reaction zone and has a constriction with an inner diameter of 50 mm and a length of 300 mm penetrating two nozzles for introducing creosote oil as a feedstock oil into the obtained high-temperature combustion gas stream, An inner diameter 1 that is provided downstream of the second reaction zone and that stops the reaction by spraying cooling water.
A furnace type carbon black production furnace in which a third reaction zone having a length of 00 mm and a length of 6000 mm was sequentially connected was installed.

(2) Refractory Material Constituting the Furnace In the above furnace, the entire first reaction zone and the second reaction zone
As a refractory material to the feedstock introduction position,
Stamping of stamp material (chemical composition MgO 99%)
Worked layer, ribbon-bonded magcro brick (chemical composition MgO
 66%, Cr _TwoO_Three 20%, Fe_TwoO_Three 7%)
Luminous brick, fire-resistant board 4-layer structure, 2nd reaction zone
As a refractory material after the introduction of raw material oil, high alumina
Refractory (Al_TwoO_Three 99%, SiO_Two 0.2%, Fe_Two
O_Three 0.2%), castable alumina, fire-resistant bow
Four-layer structure, the third reaction zone is from the inner surface
It has a two-layer structure consisting of natural brick and castable alumina.
You. (3) Stamp shape and properties before and after actual operation After continuous operation for 2 months at a furnace inner surface temperature of 1800 ° C,
Inspection of the inside of the heating furnace was carried out, but several turtles were
Although cracks were seen, no damage such as falling off was confirmed.

When the change in the layer thickness of the stamp material before and after the actual operation for the above two months was measured, the reduction was only about 2 mm even when the furnace was operated at a furnace inner surface temperature of 1800 ° C. for two months. Table 1 shows the change in the composition of the surface of the stamp material before and after the operation, but no significant change was observed in the composition before and after the operation, indicating that the composition had rather improved fire resistance. In addition, since there is no change in porosity, it is considered that there is no decrease in fire resistance. As described above, the carbon black production furnace stamped with the stamp material was found to be sufficiently practical even in actual furnace operation at an ultra-high temperature.

[0016]

[Table 1]

[0017]

According to the present invention, carbon black production at a high temperature can be achieved continuously and stably. For this reason, it has become possible to efficiently produce high-quality carbon black.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Fukuyama 1-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu

Claims (6)

[Claims] 1. A carbon black production furnace capable of producing carbon black by introducing a raw material hydrocarbon into a high temperature gas stream, wherein at least a part of the furnace wall is made of a stamp material. . 2. The carbon black production furnace according to claim 1, wherein the stamp material contains at least one of magnesia, zirconia and alumina as a main component. 3. The carbon black production furnace according to claim 1, wherein the stamp material has score lines. 4. The carbon black production furnace according to claim 1, wherein the back surface of the stamp material is made of a magnesia-chromium-based refractory material or an alumina-based refractory material. 5. The carbon black production furnace according to claim 1, wherein the thickness of the stamp material is 30 to 50 mm. 6. A method for producing carbon black, wherein a reaction for producing carbon black is carried out in the carbon black production furnace according to any one of claims 1 to 5.