JP2003277645A - Apparatus and method for producing carbon black - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for efficiently producing carbon black which has a small primary particle diameter, can form a large structure, and a narrow coagulated particle diameter distribution, and to provide a method for producing the same. <P>SOLUTION: The apparatus 10 for producing the carbon black has a first reaction zone 11 for forming a combustion gas flow, a second reaction zone 12 having a small diameter and long choke portion 20 where a raw material is supplied into the combustion gas, and a third reaction zone 13 used for stopping the reaction for producing the carbon black and disposed on the downstream side of the second reaction zone 12. Therein, the combustion gas flow in the choke portion 20 is controlled to a high temperature, a high flow speed, and a low oxygen concentration, and nozzles 21 for supplying a raw material are disposed at two or more axially different positions of the choke portion 20 to supply the raw material. Thus, the carbon black having a small particle diameter, a large coagulated particle diameter and a narrow coagulated particle diameter distribution can be produced. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing apparatus and a manufacturing method thereof for manufacturing carbon black having optimum physical properties for various uses such as a filling material, a reinforcing material, a conductive material and a coloring pigment.

[0002]

Carbon black is widely used as a pigment, a filler, a reinforcing pigment and a weather resistance improver.
The production method is as follows: the oxygen-containing gas and the fuel are introduced in the axial direction or the tangential direction of the cylindrical first reaction zone and burned to form a high temperature combustion gas flow.
While introducing and moving into a second reaction zone (also referred to as a carbon black production zone) provided on the downstream side of the reaction zone, for example, a liquid raw material is spray-supplied into the high temperature combustion gas stream to supply carbon black. A furnace-type manufacturing method for producing a high temperature combustion gas flow containing the produced carbon black, introducing the high temperature combustion gas flow to a third reaction zone provided on the downstream side of the second reaction zone, and quenching it to stop the carbon black production reaction is described. Widely known.

Carbon black used as a colorant in resin colorants, printing inks and paints is required to have excellent blackness, dispersibility, gloss and tinting strength, and is mainly used as a reinforcing agent for automobile tires. The carbon black produced is required to have excellent abrasion resistance. Blackness and tinting strength are highly dependent on the primary particle size of carbon black,
It is known that the smaller the primary particle size, the higher the blackness. The relationship between the blackness and the primary particle size is disclosed in, for example, Japanese Patent Application Laid-Open No. 50-68992. It is also known that when such carbon black having a small primary particle size is used as a reinforcing agent for a tire, it exhibits excellent wear resistance and the life of the tire is extended.

Here, in order to obtain carbon black having a small primary particle diameter, a high temperature combustion gas flow is introduced into a choke portion provided in the second reaction zone to form a high temperature and high velocity combustion gas flow, and this combustion is performed. It is well known that it is effective to spray a raw material in a gas stream, vaporize it by utilizing the kinetic and thermal energy of this combustion gas stream to thermally decompose it, and further evaporate and condense it. ing. However, the temperature of the obtained high temperature combustion gas flow is limited, and when a large amount of the raw material is supplied, a large amount of thermal energy is consumed to vaporize the raw material, and the temperature of the combustion gas flow decreases. Therefore, the amount of the raw material to be supplied to the combustion gas flow rate is reduced to prevent the temperature of the combustion gas flow from decreasing.
Carbon black having a small primary particle size is obtained by promoting vaporization, thermal decomposition and evaporation of the supplied raw material. However, there is a problem that the production amount of carbon black decreases because the supply amount of the raw material decreases.

Further, the carbon black is finally composed of an aggregate called a structure in which many primary particles are connected. Further, it has become clear that the characteristics of carbon black, which have been thought to be caused by the primary particle diameter and the structure, can be better explained as the effect of the aggregates in which they are aggregated. Therefore, as a method for quantitatively determining the size of the aggregate,
It is adopted to measure the aggregate size and its distribution by a centrifugal sedimentation method or the like. For example, for optical properties such as tinting strength and dynamic viscoelastic properties and reinforcing properties of the compounded rubber composition,
It is considered that the aggregate size and its distribution play a large role together with the primary particle size and structure. It is known that the smaller the aggregate diameter is, the higher the blackness is when it is used for resin coloring. In addition, the aggregate diameter has a great influence on tensile stress and extrusion characteristics when compounded with rubber, dispersibility, blackness, viscosity and the like when compounded with vehicle of ink or paint and resin. Therefore, controlling the diameter of the aggregate and the distribution thereof together with the primary particle diameter and the structure leads to controlling the characteristics of the carbon black itself.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have examined factors affecting the blackness of inkjet carbon black, and as a result, the primary particle size is small (for example, 15 to 30).
nm and a large structure (for example, compressed DBP
The reason is that carbon black having an oil absorption of 100 ml / 100 g to 130 ml / 100 g) and a narrow width of the aggregate size distribution (for example, 30 to 50 nm in D _1/2 ) brings about a higher blackness than the conventional one. I found something. Further, carbon black having such characteristics is used for trucks, buses, which require high wear resistance of tires,
It has been found to be the same as carbon black having the properties required in the field of tire reinforcements used in racing vehicles and the like. Therefore, development of a manufacturing apparatus and a manufacturing method capable of manufacturing a carbon black having a small primary particle diameter, a large structure, and a narrow width of agglomerate diameter distribution with high accuracy and efficiency is a major issue.

As a method for producing carbon black having a small primary particle size while ensuring the productivity of carbon black, for example, some residual oxygen is left in the combustion gas flow at the raw material supply site in the second reaction zone. A method of obtaining a carbon black having a small primary particle size by preventing the temperature of the combustion gas stream from decreasing even when a large amount of raw material is supplied by burning a part of the large amount of supplied raw material Proposed. However, in this method, since a part of the supplied raw material is used in the combustion reaction, there arises a problem that the yield of carbon black with respect to the supplied raw material deteriorates. Furthermore, the burning of a part of the raw material causes the ambient temperature in the second reaction zone to fluctuate, which adversely affects the uniform production of carbon black. Moreover, with this production method, no remarkable effect can be expected in obtaining carbon black having a large structure. On the other hand, in order to make the structure large, the generated primary particles must collide with each other at high frequency, and for that purpose, the state of the combustion gas flow in the second reaction zone needs to be in a strongly turbulent state. However, when the state of the combustion gas flow is set to a strong turbulent state, the structure becomes large, but at the same time, the width of the aggregate diameter distribution also becomes large, and the structure is large and the width of the aggregate diameter distribution is narrow. That condition will not be achieved. The present invention has been made in view of the above circumstances, and provides a manufacturing apparatus and a manufacturing method for efficiently manufacturing carbon black having a small primary particle diameter, a large structure, and a narrow aggregate diameter distribution. With the goal.

[0008]

According to a first aspect of the present invention, there is provided a carbon black producing apparatus according to the first aspect, wherein a raw material is supplied from a nozzle to a first reaction zone for forming a combustion gas stream and the combustion gas stream. An apparatus for producing carbon black, comprising: a second reaction zone having a choke part for producing carbon black; and a third reaction zone provided on the downstream side of the second reaction zone for stopping the carbon black production reaction, The choke portion has a small diameter and a long length, and the nozzles are provided on the choke portion at two or more positions in different axial directions in multiple stages.

To make the choke portion small in diameter and lengthy means that when the diameter of the choke portion is D and the length of the choke portion is L, and the ratio (L / D) is considered, the value of this ratio is, for example,
It is characterized in that 5 ≦ L / D ≦ 100 and no enlarged portion is provided. The choke portion may be a long portion having substantially the same diameter, or may have a structure in which the long portion having a smaller diameter is provided on the downstream side and the choke portion is narrowed toward the downstream side. By making the choke portion small in diameter, the flow velocity of the combustion gas flow formed in the first reaction zone can be increased. Therefore, the kinetic energy of the combustion gas flow can be increased, and the heat energy of the combustion gas flow can be efficiently transferred to the raw material supplied from the nozzle, resulting in vaporization, thermal decomposition, evaporation, and condensation of the raw material. The primary particle size of carbon black can be reduced by promoting a series of changes. In addition, by making the choke part long and not providing the enlarged part, it is possible to secure a time for mutual collision of the generated primary particles, so that the primary particles are fused to each other to obtain a large number of sizes. It is possible to efficiently form small aggregates of Further, as described above, the choke portion may be a reduction portion due to a diameter change on the downstream side thereof. The reduction ratio may be set to any value as long as it does not affect the formation of aggregates, but generally 0.85 to 0.9.
It is about 5. Further, the nozzles are provided on the choke portion at two or more positions in different axial directions in multiple stages to form an aggregate which is an aggregate of primary particles of carbon black from the raw material supplied from the upstream nozzle, The primary particles of carbon black formed from the raw material supplied from the nozzle on the downstream side are efficiently fused to the agglomerates in a shape that does not have an enlarged portion and that suppresses backflow, and coagulates. The aggregate size (aggregate diameter) can be gradually grown. As described above, by providing the nozzles for supplying the raw material in multiple stages, it is possible to secure in the second reaction zone a process in which the agglomerate is mainly formed and a process in which the agglomerate is mainly grown. Thus, it is possible to efficiently form aggregates having uniform aggregate diameters.

In the carbon black manufacturing apparatus according to the first aspect of the present invention, it is preferable that the length of the choke portion is 800 mm or more and the diameter of the choke portion is 200 mm or less. By setting the length of the choke portion to 800 mm or more and the diameter of the choke portion to 200 mm or less, it is possible to reduce carbon black
In each reaction process of forming secondary particles, forming an aggregate, and growing the obtained aggregate, it is possible to suppress variations in each reaction condition. Here, the length of the choke portion is preferably 8
It is preferable to set it to 00 to 3000 mm. 3000
Since a special effect cannot be obtained when the length exceeds mm, it is desirable to set the length to 3000 mm or less from the economical viewpoint of equipment construction. The diameter of the choke portion is preferably 200 mm or less. Preferably 30 to 200 mm, more preferably 5
It is 0 to 150 mm.

In the carbon black manufacturing apparatus according to the first aspect of the present invention, it is preferable that the nozzle is provided at a portion excluding the downstream side of the choke portion and a carbon black generation region is secured at the downstream side of the choke portion. . By providing a nozzle that supplies the raw material to the part excluding the downstream side of the choke part, the vaporization of the raw material supplied from the final nozzle,
It is possible to secure the time required for a series of changes of thermal decomposition, evaporation, and condensation, and the time required for fusing the formed carbon black to the agglomerates of the primary particles. The distance from the final nozzle to the outlet of the choke part may be appropriately set depending on the spraying conditions of the raw material, the shearing conditions of the liquid droplets in the furnace, and the like.
It is preferably 0 mm or more, and particularly preferably 400 mm or more.

According to the second aspect of the present invention, which is directed to a method for producing carbon black, the high temperature combustion gas stream formed in the first reaction zone is introduced into a small diameter and long choke portion in the second reaction zone, and high temperature, A carbon black that forms a combustion gas flow with a high flow rate and a low oxygen concentration, supplies a raw material to the choke portion through a nozzle to generate carbon black, and stops the carbon black generation reaction in the third reaction zone. In the manufacturing method, the raw material is blown into the choke portion from the nozzles provided at two or more positions in different axial directions.

By reducing the diameter of the choke portion, the first
The flow velocity of the combustion gas stream formed in the reaction zone can be increased to increase the kinetic energy of the combustion gas stream. Therefore, the raw material supplied from the first-stage nozzle on the most upstream side can efficiently absorb the thermal energy of the combustion gas flow while being mixed into the high-speed combustion gas flow. As a result, in the supplied raw material, a series of changes of vaporization, thermal decomposition, evaporation, and condensation efficiently occur with movement in the choke portion, and a large number of precursors serving as nuclei of carbon black are formed and grown. The secondary particle size becomes smaller. By making the choke part long, it is possible to secure the time for mutual collision of the generated primary particles and to gradually grow the fused aggregate of the primary particles. Furthermore, since the cross-sectional shape of the flow path does not change or is extremely small during the time required for the primary particles to fuse to the agglomerate, a high turbulence field does not occur in the combustion gas flow, which is obtained. The width of the aggregate size distribution becomes narrow.

Then, when the raw material is fed from the nozzle of the second stage while the surface of the aggregate formed from the raw material fed in the first stage is active, the fed raw material has the combustion gas flow. It absorbs thermal energy and becomes many primary particles of carbon black. While moving in the choke section, the primary particles collide with other primary particles or collide with agglomerates formed from the raw material supplied by the first stage nozzle. Since the diameter of the agglomerates is larger than that of, the collision frequency with the agglomerates is higher than the collision frequency with the primary particles. For this reason, the agglomerates fuse the primary particles that have collided while moving in the combustion gas flow to the surface thereof, so that the agglomerate diameter gradually increases. And
Carbon black is obtained by supplying the raw material from the nozzle of the third stage while maintaining the activity of the surface of the aggregate in which the primary particles formed from the raw material supplied from the nozzle of the second stage are fused. The diameter of the aggregate can be gradually increased by performing the operation of forming the primary particles of 1 above and adhering them to the surface of the aggregate. Since the aggregate diameter increases as the raw material is supplied, the frequency of collision of the primary particles of carbon black formed from the newly supplied raw material with the agglomerates will increase. The phenomenon in which existing aggregates grow is predominant rather than the formation of aggregates. As a result, the primary particle size is small (for example, 15 to 3
0 nm) and large structure (eg compressed DB
It is possible to produce carbon black having a P oil absorption of 100 ml / 100 g to 130 ml / 100 g) and a narrow width of aggregate size distribution (for example, D _1/2 of 30 to 50 nm).

In the method for producing carbon black according to the second aspect of the invention, the oxygen concentration of the combustion gas flow in the choke portion is not particularly limited, but if it is too high, the introduced raw material hydrocarbons are partially burned. However, since the generation atmosphere becomes non-uniform, it becomes difficult to obtain carbon black having a narrow agglomerate size distribution. Therefore, it is usually 10% by volume or less, preferably 8% by volume or less, more preferably 5% by volume or less, and particularly preferably 3% by volume or less. In the choke portion, it is desirable to suppress the oxygen concentration in the combustion gas flow as much as possible. This is because when the oxygen concentration in the combustion gas flow becomes high, the combustion of the raw material supplied in the choke portion becomes active, and the temperature becomes nonuniform in the choke portion. Therefore, the oxygen concentration in the combustion gas is 3% by volume or less, preferably 0.05 to 1% by volume. As a result, the ambient temperature in the region where carbon black is generated can be kept uniform. The measurement of the oxygen concentration in the choke portion can be obtained by sampling the gas in the choke portion and measuring nitrogen, oxygen, carbon dioxide, carbon monoxide, hydrogen, methane, or acetylene with a gas chromatography measuring device, for example. it can. The water generated by combustion is not included in the calculation.

In the method for producing carbon black according to the second aspect of the present invention, it is preferable that the temperature of the combustion gas flow is 1500 ° C. or higher in the choke section. 1500 ° C or higher in the choke part, preferably 1700 to 2400
By setting the temperature to be ° C, a series of changes of vaporization, thermal decomposition, evaporation, and condensation can be rapidly and uniformly caused in the raw material. Further, mutual collision of the primary particles and collision of the primary particles with the formed aggregate can be activated.

In the method for producing carbon black according to the second invention, it is preferable that the flow velocity of the combustion gas flow is 250 m / s or more in the choke portion. By setting the flow velocity of the combustion gas flow in the choke portion to 250 m / s or more, preferably 500 to 1000 m / s, the size when the raw material supplied into the choke portion is mixed into the combustion gas flow is minimized. can do. Thereby, a series of changes of vaporization, thermal decomposition, evaporation and condensation can be uniformly generated in the raw material. Here, the size of the raw material when the raw material is supplied into the combustion gas flow is determined by the relative speed difference between the flow velocity of the combustion gas flow and the ejection speed when the raw material is ejected from the nozzle, and the size of the raw material supplied into the combustion gas flow. Experiments have shown that this is related to the time it takes for the feedstock to accelerate to near the velocity of the combustion gas stream. As a result, the velocity of the combustion gas flow is 2
It was found that as the flow velocity of the combustion gas flow increases up to 50 m / s, the size of the raw material when mixed into the combustion gas flow sharply decreases, but at 250 m / s or more, it gradually decreases. There is. Therefore, the flow velocity of the combustion gas flow introduced into the choke part is 250 m / s or more, preferably 5 m / s or more.
It was set to 00 m / s or more. In addition, the flow velocity of the combustion gas flow is 25
At 0 m / s or more, the size of the raw material when mixed in the combustion gas flow decreases only moderately, and increasing the flow velocity of the combustion gas flow to more than 1000 m / s is economical for equipment construction. There are a lot of restrictions. Therefore, the upper limit is 1000
m / s.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is an overall schematic sectional view of a carbon black manufacturing apparatus according to an embodiment of the present invention, and FIG. 2 is a maximum frequency Stokes equivalent diameter (D _mod ) and Stokes equivalent diameter _half- value width (D _1/2 ). FIG. 3 is an explanatory diagram of a method for obtaining a volume 75% diameter (D ₇₅ ). As shown in FIG. 1, a carbon black manufacturing apparatus 10 according to an embodiment of the present invention is provided with a first reaction zone 11 for forming a high temperature combustion gas flow and an inflow provided downstream of the first reaction zone 11. A second reaction zone 12 for producing a carbon black by mixing the raw materials with the high temperature combustion gas stream and a third reaction zone 13 provided downstream of the second reaction zone 12 for stopping the carbon black production reaction. ing. Hereinafter, these will be described in detail.

The first reaction zone 11 includes a combustion nozzle 14 and
The combustion chamber 15 in which the fuel supplied from the combustion nozzle 14 and the oxygen-containing gas undergo a combustion reaction, and the introduction part 16 for introducing the combustion gas flow formed by the combustion reaction into the second reaction zone 12.
And have. In addition, the inside of the combustion chamber 15 and the introduction part 16 is a refractory material 17 for high temperature that can withstand a high temperature of 1500 ° C. or higher.
The general-purpose refractory 18 is further arranged outside the high-temperature refractory 17, and the iron skin 19 is provided on the outside thereof. As the fuel supplied from the combustion nozzle 14, generally, hydrogen, carbon monoxide, natural gas, petroleum gas, petroleum liquid fuel such as heavy oil, and coal liquid fuel such as creosote oil can be used. As the oxygen-containing gas, air, oxygen or a mixture thereof can be generally used. With such a configuration, the fuel is burned to form a high temperature combustion gas flow, and this gas flow is supplied to the second reaction zone 12
Can be introduced to.

The second reaction zone 12 is provided at different positions in the axial direction of the choke part 20, for example, at two positions, and the choke part 20 through which the combustion gas flow flowing in through the introduction part 16 passes, and carbon black is provided. And a nozzle 21 for supplying the raw material. The choke portion 20 is a portion whose cross-sectional area is sharply narrowed, and the length thereof is 800 mm or more, preferably 900 to 3000 mm. Here, the starting portion of the choke portion 20 (the entrance 2
5) refers to the part including the narrowest part of the flow path, and the angle of the flow path from the value exceeding 5 ° to the value of 5 ° or less from the angle with respect to the axial direction of contraction. On the other hand, the end (outlet) of the choke portion 20 has an angle of 5 with respect to the axial direction in which the flow passage expands.
The part where the value exceeds °. Also, the choke section 20
The diameter of is preferably 200 mm or less. Preferably 30
˜200 mm, more preferably 50 to 150 mm. In addition, the inside of the choke portion 20 is composed of a high temperature refractory 17 capable of withstanding a high temperature of 1500 ° C. or higher, and a general refractory 18 is disposed outside the high temperature refractory 17 and outside thereof. The iron skin 19 is provided.

The nozzles 21 are provided on the inner peripheral surface side of the choke portion 20, for example, at positions where the peripheral direction is divided into 3, 4, 6, or 8 equal parts. By providing the nozzles 21 at the divided positions, the raw material can be uniformly supplied to the combustion gas flow from the direction perpendicular to the flow direction of the combustion gas flow without disturbing the flow of the combustion gas flow. The raw materials supplied from the nozzle 21 are generally aromatic hydrocarbons such as benzene, toluene, xylene, naphthalene and anthracene, coal-based hydrocarbons such as creosote oil and carboxylic acid oil, ethylene heavy end oil, FCC oil and the like. Petroleum heavy oils, acetylene unsaturated hydrocarbons, ethylene hydrocarbons, saturated aliphatic hydrocarbons such as pentane and hexane are preferably used. When the nozzle 21 is provided on the inner side surface of the choke portion 20 over the axial direction, the position of the nozzle 21 at the uppermost stream side (first stage) is within a range of 1 ms from the inlet of the choke portion 20 based on the average cross-sectional flow velocity of the combustion gas flow. Is preferred. The range is more preferably within 0.6 ms. By introducing the raw material at this position, it is possible to obtain carbon black having a particularly small particle size and a uniform aggregate size. In addition, the second stage nozzle 21 uses a new carbon black while the surface activity of the agglomerates formed from the raw material supplied by the first stage nozzle 21 and moving in the combustion gas flow is maintained. In order to secure the time required for forming the primary particles of the above, and for ensuring the time required for the primary particles to fuse with the agglomerates and react (generate carbon black), the choke portion 2
It is provided in the region except 0 on the downstream side. The distance from the final nozzle to the outlet of the choke section 20 may be appropriately set depending on the spraying conditions of the raw material, the shearing conditions of the liquid droplets in the furnace, and the like, and is preferably 300 mm or more, particularly 400 mm or more.

As described above, the diameter of the choke portion 20 is set to 2
By setting the thickness to be equal to or less than 00 mm, the flow velocity of the combustion gas flow can be maintained at a high speed in the choke portion 20.
By increasing the effect of turbulent mixing of the combustion gas flow in 0,
The atomization of the raw material supplied from the nozzle 21 can be promoted. Further, the thermal energy of the combustion gas stream can be efficiently utilized for the carbon black forming reaction, and the rate of the carbon black forming reaction can be improved. Further, by setting the length of the choke portion 20 to 800 mm or more, the atmosphere in the choke portion 20 in which the carbon black formation reaction occurs can be kept uniform, and the reaction field can be made uniform. As a result, it is possible to efficiently form an aggregate having a uniform size. While the surface activity of the formed aggregate is maintained, the second stage nozzle 2
Since the raw material is supplied from No. 1, the primary particles of carbon black formed from the raw material supplied from the second stage nozzle 21 can be reliably fused to the aggregate. as a result,
The aggregate can be surely enlarged.

The third reaction zone 13 has a cooling chamber 22 for lowering the temperature of the combustion gas stream flowing from the second reaction zone 12.
And a nozzle 23 that is provided in multiple stages at different positions in the axial direction of the cooling chamber 22 and that supplies a refrigerant to the combustion gas flow.
And have. The refractory 18 for general use is inside the cooling chamber 22.
And a steel skin 19 is provided on the outside thereof.
The nozzles 23 are provided on the inner peripheral surface side of the cooling chamber 22, for example, at positions where the circumferential direction is divided into 3, 4, 6, or 8 equal parts. By providing the nozzles 23 at the divided positions, the refrigerant can be uniformly supplied to the combustion gas flow from the direction perpendicular to the flow direction of the combustion gas flow. Here, as the coolant supplied from the nozzle 23, a liquid such as water or a non-oxidizing gas such as nitrogen gas can be used. With such a configuration, the temperature of the combustion gas flow introduced into the cooling chamber 22 can be rapidly cooled, and finally can be lowered to 200 to 300 ° C. Therefore, the carbon black production reaction can be rapidly stopped. The rapidly cooled combustion gas flow containing carbon black is discharged from the outlet 24 of the third reaction zone to the outside of the carbon black production apparatus 10 and separated from the gas by a collection bag filter (not shown) or the like and collected.

Next, the method for producing carbon black according to one embodiment of the present invention will be described in detail. The high temperature combustion gas flow formed in the combustion chamber 15 of the first reaction zone 11 is guided to the choke section 20 provided in the second reaction zone 12. At this time, by setting the diameter of the choke portion 20 to 200 mm or less, it is possible to increase the flow velocity of the combustion gas flow introduced into the choke portion 20 and having a high temperature and a low oxygen concentration. Then, in the combustion gas flow, the choke portion 20 has two or more positions (two in the present embodiment) in different axial directions.
The raw material is blown in from a nozzle 21 provided at the location). The raw material supplied from the nozzle 21 provided on the upstream side of the choke section 20 absorbs the thermal energy of the combustion gas and undergoes a series of changes of vaporization, thermal decomposition, evaporation and condensation to form a core precursor. The primary particles of carbon black are formed. Then, the primary particles collide with each other to form an aggregate. Then, the formed particles are fused with the primary particles generated from the raw material supplied by the nozzle 21 provided on the downstream side, and the aggregate diameter is increased. At this time, by setting the length of the choke portion 20 to 800 mm or more, when the raw material is supplied in two stages, the reaction conditions of the generation of primary particles of carbon black, the formation of aggregates, and the growth of aggregates can be improved. Fluctuations can be suppressed.

At this time, the oxygen concentration of the combustion gas flow in the choke portion 20 is usually 10% by volume or less, particularly 8% by volume or less, more preferably 5% by volume or less, and particularly 3% by volume or less. The ratio of the fuel supplied from 14 and the oxygen-containing gas is adjusted. Since the oxygen concentration in the combustion gas flow in the choke portion 20 is low, the supplied raw material is less likely to burn, and the temperature in the choke portion 20 can be kept uniform. As a result, a series of changes of vaporization, thermal decomposition, evaporation, and condensation of the supplied raw material are uniformly generated, a precursor serving as a nucleus is uniformly formed, and primary particles are uniformly produced.

The temperature of the combustion gas flow flowing into the choke section 20 is 1500 ° C. or higher, preferably 1700-2.
When forming a combustion gas flow in the first reaction zone 11, for example, at 400 ° C., oxygen is added to air and combustion is performed. The method of raising the temperature of the combustion gas flow is not limited to the addition of oxygen, and it is also possible to take a method of preheating air or the like. It should be noted that the combustion gas stream in the choke portion 20 is burned so that the oxygen concentration is usually 10% by volume or less, preferably 8% by volume or less, more preferably 5% by volume or less, and further preferably 3% by volume or less. , C
The proportion of O ₂ generated increases and the amount of heat generated in the combustion reaction increases, which contributes to raising the temperature of the combustion gas flow. By setting the temperature of the combustion gas flow in the choke portion 20 to 1500 ° C. or higher, the rate of change in a series of vaporization, thermal decomposition, evaporation, and condensation of the supplied raw material is improved, and the formation rate of a precursor serving as a core, And the generation rate of primary particles can be improved.

Further, the temperature of the combustion gas stream is set to 1500 ° C. or higher, and further, the diameter of the choke portion 20 is 200 mm or less, preferably 30 to 200 mm, more preferably 50 to 150 mm, from the combustion chamber 15 through the introduction portion 16. By introducing into the choke portion 20, the flow velocity of the combustion gas flow is 250 m / s or more, preferably 500 to 1000 m / s.
Let s. As a result, when the raw material is sprayed from the nozzle 21 into the combustion gas flow, the raw material can be effectively atomized and more uniformly mixed in the combustion gas flow. As a result, the rate of change in a series of vaporization, thermal decomposition, evaporation, and condensation of the supplied raw material is improved, and the formation rate of the precursor serving as a core and the production rate of primary particles can be improved.

As described above, the oxygen concentration in the combustion gas flow in the choke portion 20, the temperature of the combustion gas flow, and the flow velocity are adjusted to supply from the nozzle 21 provided on the upstream side of the choke portion 20. Vaporization, pyrolysis, evaporation of
A series of changes of condensation can be performed uniformly and at high speed, a large number of nuclei can be formed, and many primary particles can be generated, and as a result, the generated primary particles are also small. Further, the generated primary particles fuse with each other to be fused and form aggregates, but due to the high temperature, the collision frequency between the primary particles is high, and many aggregates are rapidly formed. Therefore, an aggregate having a small aggregate diameter and a narrow aggregate diameter distribution is formed.

Subsequently, when the raw material is supplied from the downstream nozzle 21 while the surface of the aggregate formed from the raw material supplied from the upstream nozzle 21 is active, the supplied raw material is removed from the combustion gas flow. The transferred thermal energy becomes a large number of primary particles of carbon black. The formed primary particles collide with each other when moving in the choke portion, or collide with the agglomerates formed from the raw material supplied in the first stage. The frequency of collisions with particles is higher than the frequency of collisions between primary particles.
For this reason, the agglomerates fuse the primary particles that have collided while moving in the combustion gas flow to the surface thereof, so that the agglomerate diameter gradually increases. Here, since the agglomerates fuse the colliding primary particles and increase the diameter thereof, the frequency of collision of the primary particles with the agglomerates further increases and new agglomerates are formed. Rather, the phenomenon of growth of existing aggregates becomes dominant. Therefore, the width of the aggregate diameter distribution of the aggregates formed is narrowed.

The high-temperature, high-velocity combustion gas flow containing the agglomerates of carbon black formed during passage in the choke portion 20 flows into the cooling chamber 22 from the outlet of the choke portion 20. Since the diameter of the cooling chamber 22 is larger than the diameter of the choke portion 20, the flow velocity of the combustion gas flow decreases. Further, on the inner peripheral surface side of the cooling chamber 22, for example, in the circumferential direction 4,
Nozzles 23 that eject water, for example, are provided in multiple stages at positions such as 6 or 8 equal parts. By jetting water from these nozzles 23 in a direction perpendicular to the flow direction of the combustion gas flow, the temperature of the combustion gas flow is rapidly cooled and the carbon black production reaction is rapidly stopped. Then, the temperature of the combustion gas flow is finally set to 200 to 3
Decrease to 00 ° C. As a result, the carbon black agglomerates contained in the combustion gas flow are contained in the mixed gas flow of the steam and the combustion gas formed from the water ejected for cooling, and are discharged from the outlet of the third reaction zone 13. It is discharged from the carbon black manufacturing apparatus 10 from 24, separated from the mixed gas by a collection bag filter (not shown), and collected.

[0031]

EXAMPLES In Examples 1 and 2 relating to the carbon black producing apparatus and method according to the present invention, the combustion nozzle 14 is used.
Combustion chamber 1 with inner diameter of 500 mm and length of 1500 mm
5, a first reaction zone 11 having a second reaction zone 12 connected to the first reaction zone 11 and having a choke portion 20 having an inner diameter of 50 mm and a length of 1400 mm connected to a plurality of raw material supplying nozzles 21 from the periphery. A carbon black manufacturing apparatus 10 having a structure in which a third reaction zone 13 having a cooling chamber 22 having an inner diameter of 200 mm and a length of 1,500 mm, which is provided through a plurality of nozzles 23 for supplying water from the periphery, was sequentially connected was installed. In addition, the nozzle position for supplying the most upstream raw material is the choke part 2
0 entrance 25 to 200 mm. Using the carbon black production apparatus 10 described above, carbon black was produced under the conditions shown in Tables 1 and 2. Natural gas was used as the fuel, and creosote oil was used as the raw material hydrocarbon. In Tables 1 and 2, the temperature of the combustion gas flow, the oxygen concentration of the combustion gas flow, and the furnace pressure are the choke part 2 for supplying the raw material.
It is within 0.

Table 3 shows the respective characteristics of the obtained carbon black.
Shown in. Each characteristic value was obtained by the following method. Specific Surface Area (SN ₂ ) Obtained by Nitrogen Adsorption Method As a sample, carbon black that was previously heated was set in a U-shaped tube, and this U-shaped tube was immersed in liquid nitrogen to cool the carbon black. Then, a sample gas mixed with a carrier gas of pure nitrogen gas at a ratio of 15% by volume of nitrogen gas and 85% by volume of helium gas is introduced into the U-shaped tube, and the nitrogen gas in the carrier gas is adsorbed on the carbon black. This desorption signal is counted and the specific surface area is calculated by the following formula. SN ₂ = (1 / W) ・ (1-P / P ₀ ) ・ (A / _AC )
V _C 1188P _a / (273 + T) P _a : atmospheric pressure, P ₀ : saturated vapor pressure, A _C : calibration signal value,
A: surface area signal value, V _C : calibration gas amount, W: sample mass,
T: Temperature crushed DBP absorption number (CrDBP) 25 g of carbon black was put in a cylinder, a piston was inserted, and 24000 psi (1687) with a hydraulic press.
A pressure of kg / cm ² ) is applied for 5 seconds. After the pressurization, the obtained carbon black lump is taken out, transferred to a 1000 μm sieve to loosen the carbon black lump, and passed through the sieve. The sample obtained by repeating this operation 4 times is JISK
Measure DBP oil absorption according to 6221 and crush DBP
The absorption number. Maximum frequency Stokes equivalent diameter (D _mod ),
Stokes equivalent diameter _half- value width (D _1/2 ) and volume 75% diameter (D ₇₅ ) Surfactant (“NO manufactured by SIGMA CHEMICAL”
A precisely-measured carbon black was added to a 20% aqueous ethanol solution containing 3 drops of NIDET P-40 "to prepare a sample solution having a carbon black concentration of 0.01% by weight. This sample solution is ultrasonically dispersed using an ultrasonic disperser (“Ultrasonic generator USV-500V” manufactured by Ultrasonics Co., Ltd.) with a frequency of 200 kH.
A carbon black slurry was obtained by performing a dispersion treatment for 5 minutes at an output of 100 W. On the other hand, a centrifugal sedimentation type flow rate distribution measuring device (BROOKHAVEN IN
"BI-DCP PARTIC" manufactured by STRUMENTS
10 ml of the spin liquid (pure water) is further injected into the LSIZER "), 1 ml of the buffer liquid (20% ethanol aqueous solution) is further injected, and then 1 ml of each of the carbon black slurry prepared above is injected, and the spin is performed at a rotation speed of 10000 rpm. The Stokes equivalent diameter is measured by sedimentation, and as shown in FIG. 2, a histogram of the occurrence frequency relative to the Stokes equivalent diameter is created. A straight line B is drawn parallel to the Y-axis from the peak (A) of the histogram, and the intersection with the X-axis of the histogram is C. The Stokes diameter at C at this time is the maximum frequency Stokes equivalent diameter (D _mod ). Also, let F be the midpoint of line B and F
Draw a straight line G parallel to the X-axis. The straight line G intersects the distribution curve of the histogram at two points D and E. At this time, D
The absolute value of the difference between the Stokes diameters at E and E is the Stokes equivalent diameter _half- value width (D _1/2 ) value. Volume 75% diameter (D
₇₅ ) was determined as follows. From the histogram of Figure 2,
The volume of the aggregate of each Stokes diameter is obtained from each Stokes diameter and the frequency at that time, and the relation of the cumulative volume up to the Stokes diameter to the Stokes diameter is calculated. The relationship is shown as a curve R in FIG. In addition, in FIG. 3, P represents the sum total value of the volume of the aggregate of each Stokes diameter. Here, a point having a value of 75% of the total volume value is designated as Q, a straight line is drawn from Q in parallel with the X axis, and an intersection with the curve R is designated as S. Then, a straight line is drawn from S in parallel with the Y axis, and the point of intersection with the X axis is T. The value of T at this time is the volume 75% diameter (D ₇₅ ).

The particle size of the primary particles of carbon black is
Determined by electron microscopy. Electron microscopy is the method described below. Carbon black is put into chloroform, and ultrasonic waves of 200 KHz are irradiated for 20 minutes to disperse the carbon black, and then the dispersed sample is fixed to a support film. This is photographed with a transmission electron microscope, and the particle diameter is calculated from the diameter on the photograph and the magnification of the photograph. This operation is performed about 1500 times, and it calculates | requires by the arithmetic mean of those values.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

Comparative Examples 1 to 3 were carried out under the conditions shown in Table 1 using the carbon black production apparatus used in the examples. The physical properties of the obtained carbon black are shown in Table 2. Comparative Example 1
Does not divide the raw material in the axial direction of the furnace and does not secure a sufficient distance from the introduction point to the choke outlet.
This is an example of producing carbon black of 00 m ² / g. CrDBP is increased due to turbulent flow at the outlet,
D _1/2 / D _mod and D _{75 of the} aggregate size distribution show large values. Comparative Example 2 is a production example in which carbonaceous material having a specific surface area of about 300 m ² / g was obtained by similarly not dividingly introducing the raw material in the axial direction of the furnace and ensuring a sufficient distance from the introduction point to the choke outlet. However, D _1/2 / D _mod and D ₇₅ of the aggregate size distribution were smaller than those of Comparative Example 1, but Cr
DBP was low. Comparative Example 3 is an example in which carbon black having a specific surface area of 230 m ² / g was produced from the same introduction point as that of Comparative Example 2.
BP is low. From these examples, it can be seen that high CrDBP and narrow aggregate size distribution are not compatible. On the contrary,
In Example 1, the first-stage raw material introduction point was set to be 200 mm downstream from the long choke having a length of 1400 mm, and the second-stage raw material introduction point was set 500 mm away from the choke outlet, and the specific surface area was about 290 m. ^{Although this} is an example of producing ² / g of carbon black, it can be seen that the aggregate diameter distribution is extremely sharp in comparison with Comparative Example 1 despite the fact that CrDBP is equivalent. Further, as can be seen by comparing with Comparative Example 2 which has almost the same specific surface area, high C
rDBP has been obtained with extremely low D _1/2 / D _mod and D ₇₅ . Example 2 is an example in which carbon black having a specific surface area of about 190 m ² / g was produced by the same production method as in Example 1, but it has a lower specific surface area than Comparative Example 3, It can be seen that high CrDBP is obtained with low D _1/2 / D _mod and D ₇₅ . Therefore, when such a carbon black is used for carbon black for inkjet, it is possible to provide a higher blackness than the conventional one. Further, when carbon black having such characteristics is used as a tire reinforcing material used in trucks, buses and racing vehicles, extremely high wear resistance can be obtained.

Although the present invention has been described in the above embodiment, the present invention is not limited to this embodiment. For example, the nozzles for supplying the raw material are installed at two positions. The number may be three or more. Further, changes can be made without changing the gist of the invention, and a part or all of the above-described respective embodiments and modifications are combined to configure the carbon black manufacturing apparatus and the manufacturing method thereof. The present invention is also applied to the case.

[0039]

In the carbon black manufacturing apparatus according to the first to third aspects of the present invention, the choke portion has a small diameter and a long length, and the nozzles are provided on the choke portion in two or more axially different positions in multiple stages. Therefore, it is possible to produce carbon black having a small primary particle diameter, a large aggregate diameter, and a narrow width of the aggregate diameter distribution.

Particularly, in the carbon black producing apparatus according to the second aspect, since the length of the choke portion is 800 mm or more and the diameter of the choke portion is 200 mm or less, 1
It is possible to easily obtain carbon black having a small secondary particle size and a narrow width of the aggregate size distribution.

In the apparatus for producing carbon black according to the third aspect, the nozzle is provided at a portion other than the downstream side of the choke portion, and a carbon black generation region is secured on the downstream side of the choke portion. The yield can be improved.

In the method for producing carbon black according to claims 4 to 7, the raw material is blown into the choke portion from nozzles provided at two or more positions in different axial directions, and the primary particle diameter is small and the structure is large. In addition, it is possible to produce carbon black having a narrow width of aggregate size distribution.
High blackness can be achieved by using it as a coloring pigment for resin coloring, paint, lacquer and the like. Furthermore, by using it as a tire reinforcing material, it becomes possible to manufacture a highly wear-resistant tire for use in trucks, buses, race vehicles and the like.

Particularly, in the method for producing carbon black according to the fifth aspect, since the oxygen concentration of the combustion gas flow is 8% by volume or less in the choke portion, the atmospheric temperature in the region where carbon black is generated is kept uniform. It is possible to obtain carbon black having a small primary particle size and a sharp aggregate size distribution. Further, since the partial combustion of the supplied raw material is suppressed, the production yield of carbon black is improved.

In the method for producing carbon black according to claim 6, the temperature of the combustion gas flow is 1 in the choke portion.
Since the temperature is 500 ° C or higher, vaporization, thermal decomposition, evaporation of raw materials,
It is possible to produce carbon black having a small primary particle size by uniformly causing a series of changes in condensation. Further, the mutual collision of the primary particles becomes active to allow the formation of a large number of aggregates, and the collision between the formed aggregates and the primary particles becomes active to promote the growth of the aggregates. Is possible.

In the method for producing carbon black according to claim 7, the flow velocity of the combustion gas flow is 2 in the choke portion.
Since it is 50 m / s or more, the size of the raw material supplied from the nozzle can be reduced to uniformly generate a series of changes of vaporization, thermal decomposition, evaporation, and condensation of the raw material, and a carbon having a small primary particle diameter. It becomes possible to manufacture black.

[Brief description of drawings]

FIG. 1 is an overall schematic cross-sectional view of a carbon black manufacturing apparatus according to an embodiment of the invention.

FIG. 2 is an explanatory diagram of how to determine a maximum frequency Stokes equivalent diameter (D _mod ) and a Stokes equivalent diameter _half- value width (D _1/2 ).

FIG. 3 is an explanatory diagram of how to determine a volume 75% diameter (D ₇₅ ).

[Explanation of symbols]

10: carbon black production apparatus, 11: first reaction zone, 12: second reaction zone, 13: third reaction zone, 14:
Combustion nozzle, 15: combustion chamber, 16: introduction part, 17: high temperature refractory, 18: general refractory, 19: iron skin, 20: choke part, 21: nozzle, 22: cooling chamber, 23: nozzle, 24: Exit, 25: Entrance

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takaharu Yamamoto             1-1 Kurosaki Shiroishi, Hachiman Nishi Ward, Kitakyushu City, Fukuoka Prefecture               Within Mitsubishi Chemical Corporation (72) Inventor Azuma Tsunemasa             1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Corporation             Inside the company F term (reference) 4J037 AA02 BB18 BB25 BB29 BB33                       BB37

Claims (7)

[Claims] 1. A first reaction zone for forming a combustion gas stream, a second reaction zone having a choke portion for supplying a raw material from the nozzle to the combustion gas stream to produce carbon black, and a second reaction zone of the second reaction zone. An apparatus for producing carbon black having a third reaction zone which is provided on a downstream side and which stops a reaction of producing carbon black, wherein the choke portion has a small diameter and a long length, and the nozzle is axially provided to the choke portion. An apparatus for producing carbon black, characterized in that the carbon black is provided in multiple stages at two or more different positions. 2. The carbon black manufacturing apparatus according to claim 1, wherein the length of the choke portion is 800 mm or more and the diameter of the choke portion is 200 mm or less. 3. The carbon black manufacturing apparatus according to claim 1 or 2, wherein the nozzle is provided at a site other than the downstream side of the choke portion, and a carbon black generation region is secured on the downstream side of the choke portion. An apparatus for producing carbon black, which is characterized in that 4. The high temperature combustion gas stream formed in the first reaction zone is introduced into a small diameter and long choke portion of the second reaction zone to form a high temperature, high velocity and low oxygen concentration combustion gas stream, In the method for producing carbon black, in which a raw material is supplied to the choke portion through a nozzle to generate carbon black and the carbon black production reaction is stopped in the third reaction zone, the choke portion is provided at two or more locations in different axial directions. The method for producing carbon black, characterized in that the raw material is blown from the nozzle provided at the position. 5. The method for producing carbon black according to claim 4, wherein the oxygen concentration of the combustion gas stream in the choke portion is 8% by volume or less. 6. The method for producing carbon black according to claim 4 or 5, wherein the temperature of the combustion gas flow is 1500 ° C. or higher in the choke section. 7. The method for producing carbon black according to claim 4, wherein the flow rate of the combustion gas flow is 250 m / s or more in the choke portion. Manufacturing method.