JPH11335577A - Preparation of carbon black - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbon black which satisfies both a high degree of blackness and a high dispersibility which have conventionally been in the relationship of antinomy and therefore have been difficult to be simultaneously achieved when used as a black pigment in resin colorants, printing inks or coatings. SOLUTION: A preparation process of carbon blacks uses a preparation oven possessing a first combustion reaction zone wherein a high-temperature combustion gas stream is formed, a second reaction zone having a choke part wherein the obtained high-temperature combustion gas stream is mixed with a material hydrocarbon to prepare carbon blacks and a third reaction zone wherein the reaction is stopped, which is positioned at the downstream of the second reaction zone. Here, the flow rate of the combustion gas inside the choke part is 250 m/s or larger, and the entrance angle of the choke part is from 45 to 100 deg..

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 used for various uses such as filling materials, reinforcing materials, conductive materials and coloring pigments, and to an effective method for controlling the physical properties thereof. .

[0002]

2. Description of the Related Art Carbon black is widely used as a pigment, a filler, a reinforcing pigment, and a weather resistance improver. Generally, carbon black is produced in a first reaction zone of a cylindrical carbon black production furnace in a furnace axial direction. Alternatively, the oxygen-containing gas and the fuel are introduced tangentially, and the high-temperature combustion gas stream obtained by these combustions is subsequently moved to a second reaction zone having a reduced cross-sectional area installed in the furnace axis direction. Meanwhile, a furnace type production method in which a raw material hydrocarbon is introduced into the gas stream to generate carbon black, and the reaction gas is rapidly cooled in a third reaction zone to stop the reaction is widely known.

[0003] Carbon black used as a colorant in resin colorants, printing inks and paints is required to have excellent blackness, dispersibility, gloss and coloring power, and is mainly used as a reinforcing agent for automobile tires. The carbon black to be used is required to have excellent wear resistance. Blackness and tinting strength depend greatly on the primary particle size of carbon black,
It is known that the smaller the primary particle diameter, the higher the blackness. For example, the relationship between blackness and primary particle size is disclosed in
No. 68992. Further, it is known that such carbon black exhibits a high degree of wear resistance when used as a tire reinforcing agent.

[0004] The distribution of the primary particle diameter also has a significant effect on the rubber properties, particularly on tire tread rubber compositions that require high abrasion resistance, and it is considered that the narrower the primary particle diameter distribution is, the better. . Generally, the smaller the average particle diameter, the narrower the distribution. However, a method of narrowing the primary particle diameter distribution has also been disclosed (Japanese Patent Laid-Open No. 33167/1991). Aggregates are factors that affect the properties of carbon black as well as the primary particle size. The size of the agglomerates greatly affects the tensile stress and extrusion characteristics when compounded with rubber, the dispersibility, blackness and viscosity when compounded with ink and paint vehicles and resins. Carbon black is ultimately composed of aggregates of many primary particles, and controlling the size and shape of these aggregates leads to controlling the properties of carbon black itself, It may be more important than controlling the primary particle size.

[0005] Agglomerates have a significant effect on the properties of carbon black, and many of the properties of carbon black, which have heretofore been attributed to the primary particle size, can sometimes be better explained by the aggregate size. It has become clear. For example, it is considered that the aggregate diameter and its distribution play a large role in optical properties such as coloring power and dynamic viscoelastic properties and reinforcing properties of the compounded rubber composition. It is known that the smaller the agglomerate diameter, the higher the degree of blackness when viewed in resin coloring applications. In general, as a method of reducing the diameter of the aggregates, an alkali metal salt or a solution thereof is added to a raw material oil, or is burned or introduced into a reaction zone. However, when incorporated into vehicles and resins of inks and coatings, the reduction in particle size and the size of aggregates cause deterioration in dispersibility and fluidity. Therefore, regarding the relationship between the characteristics of carbon black and the physical properties of the resin, it is important how to satisfy blackness and dispersibility, which are generally in a trade-off relationship.

[0006]

SUMMARY OF THE INVENTION The present invention provides a method for efficiently producing carbon black satisfying both high blackness and good dispersibility. The present invention provides a production method for efficiently obtaining carbon black having a small primary particle diameter, a small aggregate diameter, and a small width of aggregate distribution.

[0007]

Means for Solving the Problems The present inventors analyze the dispersion behavior of carbon black in a matrix and the factors affecting blackness to obtain carbon black having higher blackness and better dispersibility than before. Therefore, as a result of various studies, it was found that carbon black having fine aggregates having no adverse effect on dispersion and uniform aggregates without large aggregates having an adverse effect on blackness had high blackness and good dispersibility. That is, carbon black having a small particle diameter, a small aggregate diameter, and a sharp distribution of the aggregate diameter is high in blackness and has good dispersibility, that is, the blackness and the dispersibility problem which have been considered to have the above trade-off relationship Was found to solve the problem.

Accordingly, the inventors have further studied the conditions for efficiently producing carbon black having the above-mentioned excellent characteristics. As a result, by using a carbon black production furnace having a specific choke portion, by setting the flow rate of the combustion gas in the choke portion to a specific range,
It has been found that carbon black having the above-mentioned excellent properties can be efficiently produced. That is, the present invention provides a second combustion reaction zone having a first combustion reaction zone for forming a high-temperature combustion gas stream and a second choke section for mixing a raw material hydrocarbon with the obtained high-temperature combustion gas stream to produce carbon black.
In a method for producing carbon black using a production furnace having a reaction zone and a third reaction zone downstream of a second reaction zone for stopping the reaction, the flow rate of the combustion gas in the choke portion is set to 250 m / s or more, Entrance angle 45
~ 100 °, a method for producing carbon black.

The present invention further provides a first reaction zone for forming a high-temperature combustion gas stream, and a second reaction zone having a choke section for mixing a raw material hydrocarbon with the obtained high-temperature combustion gas stream to produce carbon black. An apparatus for producing carbon black having a third reaction zone downstream of the second reaction zone for stopping the reaction, wherein the chalk inlet angle is 45.
~ 100 ° in a carbon black producing apparatus. By changing various conditions such as the charged amount of the raw material hydrocarbon within the range defined in the production method of the present invention, carbon black having various desired physical properties can be produced. Therefore, various kinds of carbon blacks that can be used for various purposes can be arbitrarily produced in high yield.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The present invention provides a carbon black producing apparatus having a first reaction zone, a second reaction zone, and a third reaction zone, wherein carbon black is obtained by introducing a raw material hydrocarbon.
It relates to the so-called furnace method. The configuration of the present invention will be described with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of an essential part showing an example of the carbon black producing apparatus of the present invention.

The furnace has a first reaction zone 1 for forming a high-temperature combustion gas stream in a longitudinal direction, and a choke section for mixing the obtained high-temperature combustion gas stream with a raw material hydrocarbon to produce carbon black. It is divided into a second reaction zone 2 (having a choke section 4) and a third reaction zone 3 downstream of the second reaction zone, which stops the reaction. The process itself in each reaction zone can basically adopt the same method as in the prior art. In the first reaction zone, generally the combustion nozzle 5
To introduce a fuel hydrocarbon and an oxygen-containing gas to generate a hot gas stream. Air, oxygen or mixtures thereof are used as the oxygen-containing gas, and hydrogen, carbon monoxide, natural gas, petroleum gas and petroleum liquid fuels such as heavy oil, coal-based liquid fuels such as creosote oil are used as fuel hydrocarbons. Is used.

In the second reaction zone, the raw hydrocarbon is spray-introduced into the choke section from the raw hydrocarbon introduction nozzle 6 provided in parallel or in the horizontal direction with the high-temperature gas flow obtained in the first reaction zone.
The raw hydrocarbon is pyrolyzed and converted into carbon black. In FIG. 1, reference numeral 7 denotes a reaction stopping fluid introduction nozzle, and reference numeral 8 denotes a control valve. The raw material hydrocarbons are generally aromatic hydrocarbons such as benzene, toluene, xylene, naphthalene and anthracene; coal-based hydrocarbons such as creosote oil and carboxylic acid oil; and heavy petroleum oils such as ethylene heavy-end oil and FCC oil. And acetylenically unsaturated hydrocarbons, ethylene hydrocarbons, and aliphatic saturated hydrocarbons such as pentane and hexane.

[0013] The third reaction zone is a hot reaction gas 1000 ~
Water or the like is sprayed from the reaction stop fluid introduction nozzle 7 in order to cool it to 800 ° C. or less. The cooled carbon black is subjected to a known general process such as separation and recovery from gas with a collecting bag filter or the like. The present invention is characterized in that a specific choke portion is used in the above-mentioned second reaction zone. That is, the chalk portion entrance angle is 45 ° to 100 °, preferably 80 ° to 90 °,
More preferably, the choke is at 90 °. In addition,
The choke inlet angle refers to the angle on the upstream side of the flow path among the angles formed by the wall surface of the choke inlet converging portion and the furnace axis, and is the angle corresponding to 12 in FIG. When this value is from 45 ° to 90 °, as this value is larger, the rate of decrease in the cross-sectional area with respect to the distance on the furnace axis becomes sharper toward the choke portion. In FIG. 2, reference numeral 9 denotes a choke portion inlet portion, 10 denotes a choke portion, 11 denotes a combustion gas flow direction, and 12 denotes a choke portion inlet angle. The length of the choke is not particularly limited, but is preferably 800 mm or more.

According to the study of the present inventors, in order to achieve the reduction of the primary particle size of the carbon black, droplets of the raw hydrocarbon immediately after the raw hydrocarbon is introduced into the combustion gas in the production furnace. It was found that reducing the diameter as much as possible was effective. In the production of carbon black, it has been conventionally known to utilize the kinetic and thermal energy of high-speed combustion gas for atomizing raw material hydrocarbons. Therefore,
Further studies on the atomization mechanism of droplets in a high-speed airflow revealed that the atomization of the droplets by the airflow occurred until the relative velocity difference between the gas and the particles and the particles sprayed into the airflow were accelerated to near the speed of the airflow. It turned out to be related to my time.

When the relationship between the final diameter after the raw material hydrocarbon is atomized and the gas flow rate is examined, the gas flow rate becomes 250
It was found that the final diameter rapidly decreased as the gas flow velocity increased up to m / s, but gradually decreased at 250 m / s or more. Therefore, the flow velocity of the gas introduced into the constricted portion needs to be 250 m / s or more, preferably 500 m / s.
The present inventors have clarified that it is desirable to introduce raw material hydrocarbons in a direction substantially transverse to the gas flow into the constriction section. Therefore, 250 m / s
If it is less than 30, the effect of sufficiently reducing the particle size aimed at in the present invention cannot be obtained. Further, in the present invention, the choke portion entrance angle is 45 ° or more and 100 ° or less. Preferably it is 80 ° or more and 90 ° or less, more preferably 90 °. The present inventors have found that, particularly in this range, a particle having a small particle diameter, a small aggregate diameter and a sharp aggregate diameter distribution can be easily obtained.

As described above, the reason why carbon black having preferable physical properties can be obtained by passing through a choke portion having a specific range of inlet angle at a flow rate of a specific value or more in the present invention is probably that By keeping the combustion gas flow rate high and steepening the angle of the choke inlet, the size of the turbulent mixing of the gas in the choke increases, and the atomization of the raw hydrocarbon droplets is promoted. Not only that, the atmosphere in which the carbon black generation reaction occurs becomes uniform, and the heat energy of the combustion gas can be used efficiently for the carbon black generation reaction, so the reaction speed increases and the reaction field becomes uniform, This is considered to be because carbon black can be generated and carbonized in a short time.

Since it takes time and effort to perform experiments for changing the entrance angle of the choke section in various ways, the present inventors have developed a program for simulating the carbon black generation process using a computer.
The change of the entrance angle was examined using the program. This program combines a thermofluid analysis program using the finite difference method, which is widely used, with a program for generating primary particles of carbon black based on classical nucleation theory developed by the present inventors. By changing the furnace shape and operating conditions, it is possible to predict how the primary particle size and the distribution of the produced carbon black will change. Specifically, "Aerosol Research Vol. 12 No. 3, pp. 175-182 (1997) ".

In order to uniformly disperse the starting hydrocarbons in the furnace, the starting hydrocarbons are preferably introduced into the furnace from two or more nozzles. By doing so, it is possible to obtain carbon black which is particularly sharp in both the aggregate diameter and the particle diameter. The feed position of the raw material hydrocarbon is also an important factor, and according to the studies of the present inventors, in order to produce carbon black having a small particle diameter and a uniform aggregate diameter, the hydrocarbon feed position is a chalk portion. It has been found that it is suitable to be located within 1 ms, more preferably within 0.6 ms, based on the average cross-sectional flow velocity of the combustion gas from the chalk inlet. After the introduction of the raw material hydrocarbon, the residence time in the chalk is preferably 0.4 ms or more.
Thereby, carbon black having particularly sharp aggregate diameter distribution can be easily obtained. It is considered that the agglomerates are formed by condensing the raw material hydrocarbons after thermal decomposition, condensing them into droplets, forming a core precursor pair, fusing and carbonizing through mutual collision. Therefore, it is considered that by setting the residence time in the chalk within the above range, aggregates can be generated without receiving a high disturbance field due to a change in the flow path or the like.

Here, the residence time in the choke is the time from when the raw material hydrocarbon is charged into the furnace to when it reaches the choke outlet. The entrance of the choke portion, which is the start portion of the choke portion, includes the narrowest portion of the flow path and refers to a portion where the angle of the flow path with respect to the reducing axial direction changes from a value exceeding 5 ° to 5 ° or less. On the other hand, the exit of the choke portion, which is the end of the choke portion, has an angle of 5 ° with respect to the axial direction in which the flow path is reduced.
Refers to a part with a value exceeding ゜. The temperature at the position where the hydrocarbon is introduced is preferably 1600-1700 ° C.,
It is more preferably 1700 to 2400 ° C, and still more preferably 1800 to 2400 ° C. In this range, a particularly high temperature atmosphere is provided for the raw material hydrocarbons to be uniformly vaporized and thermally decomposed, and carbon black having particularly sharp particle size distribution and aggregate size distribution is obtained.

The oxygen concentration at the starting hydrocarbon introduction site is preferably 3 vol% or less. More preferably, it is 0.05 to 1 vol%. The presence of oxygen in the combustion gas causes a partial combustion of the raw hydrocarbons in the reaction zone,
This results in non-uniform reaction zones. In the prior art, furnace black was considered to be produced by partial combustion of the feedstock, so the residual oxygen concentration in the combustion gas at the feedstock introduction site was set to about 5 to 10 vol%, and the feedstock was partially burned. However, surprisingly, according to the inventors' studies, the lower the oxygen concentration at the site where the raw material hydrocarbon is introduced, the higher the rate of generation of CO ₂ in the combustion reaction, the larger the calorific value in the combustion reaction, Because the combustion gas is heated to a higher temperature, the yield is significantly improved, and the partial combustion of the feedstock is less,
It has been found that the atmosphere in the region where carbon black is generated is kept uniform, and that carbon black having a particularly sharp aggregate size distribution can be obtained.

In the measurement of the oxygen concentration at the feed hydrocarbon introduction position, the gas at the feed hydrocarbon introduction site is sampled,
For example, nitrogen, oxygen,
It can be determined by measuring carbon dioxide, carbon monoxide, hydrogen, methane, and acetylene. Water generated by combustion is not included in the calculation. The flow rate of the combustion gas in the choke section was set to 250 m
/ S, the chalk inlet angle is 45 ° to 100 °, and the temperature at the hydrocarbon introduction position is 1800 to 2400 ° C
Is difficult to achieve with the conventional technology. That is, conventionally, the furnace is generally made of a refractory material, and under the above-mentioned conditions, especially the chalk inlet portion is quickly worn away, and it is impossible to operate for a long period of one year or more.

The inventors have solved this problem by using a metal choke having a water-cooled jacket structure for the choke portion. Using metal chalk of water cooling jacket structure,
As a result of adopting a structure in which this metal portion is used at the 90 ° edge portion of the chalk inlet, no abrasion was observed at the chalk inlet. Hitherto, there have been many descriptions of constructing a chalk portion using a metal material. For example, Japanese Patent Laying-Open No. 47-563 discloses a structure in which a first reaction zone and a second reaction zone are made of a material having high thermal conductivity, for example, metal, and a suitable liquid coolant is circulated inside a cooling jacket. Have been. However, there is no description about the angle of the entrance of the choke portion, which is different from the present invention.

According to the method for producing carbon black of the present invention described above, carbon black having a small aggregate, a sharp distribution, a small particle diameter, and excellent characteristics can be efficiently obtained. . Conventionally, centrifugal sedimentation in an aqueous dispersion of cDBP or carbon black and electron microscopic analysis have been known as evaluation indexes for aggregates. Recently, centrifugal sedimentation has been used to evaluate the size and distribution of aggregates. ing. In the examples of the present invention, the maximum frequency Stokes equivalent diameter D _mod and the half width D _1/2 of the maximum frequency Stokes equivalent diameter in the aggregate Stokes equivalent diameter distribution by the centrifugal sedimentation method as an index of the sharpness of the aggregate diameter. Was evaluated using the ratio of According to the carbon black production apparatus of the present invention and the method for producing carbon black of the present invention, the average particle diameter is 25 nm or less, and the half-width D1 _{/ 2} of the maximum frequency Stokes equivalent diameter in the aggregate Stokes equivalent diameter distribution by the centrifugal sedimentation method is the largest. The ratio with the frequency Stokes equivalent diameter D _{mod, that} is, the ratio of D _1/2 / D _mod is 0.6
The following carbon black having a small particle diameter and a small aggregate diameter and a sharp aggregate diameter distribution can be efficiently obtained. Furthermore, carbon black having an average particle diameter of 20 nm or less, which is more preferable for increasing the PVC blackness, can be easily obtained.

[0024]

The present invention will be described below with reference to examples of the present invention.
The present invention is not limited to this. (Examples 1 to 5) As shown in FIG. 1, a first reaction zone having an inner diameter of 500 mm and a length of 1400 mm provided with an air introduction duct and a combustion burner is connected to the first reaction zone, and a plurality of raw material nozzles are penetrated from the periphery. 60mm inside diameter, 800mm length
A second reaction zone having a choke portion, a third reaction zone having an inner diameter of 100 mm and a length of 6000 mm equipped with a quench device,
Further, a carbon black manufacturing apparatus having a structure in which control valves having an inner valve diameter of 80 mm were sequentially connected as a throttle mechanism was installed. Note that the entrance angle of the choke portion is 90 °.

Using the above production apparatus, carbon black was produced according to the conditions shown in Table 1. Fuel and
Creosote oil was used as the starting hydrocarbon. Table-1
The “combustion gas temperature”, “combustion gas oxygen concentration” and “furnace pressure” are those at the site where the raw hydrocarbon is introduced. The “potassium concentration” defines the concentration of KOH added to the raw material hydrocarbon as the concentration of potassium. Table 2 shows various properties of the obtained carbon black. The following test method was used to determine the analytical properties of the carbon black produced according to the present invention.

(Average particle diameter) According to electron microscopy. Electron microscopy is a method described below. Carbon black is injected into chloroform and 200 KHz ultrasonic wave is applied for 20 minutes.
After irradiating for minutes, the dispersion sample is fixed to a support membrane. 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 the values are obtained by arithmetic averaging.

(N ₂ SA Specific Surface Area) The N ₂ SA specific surface area was determined according to ASTM D3037-88. (SEM specific surface area) The SEM specific surface area was calculated from the following equation. SEM = 6000 / (ρ · dA) ρ: Specific gravity of carbon black (1.86 g / cm ³ ) dA: Body area particle diameter (nm)

(CDBP) Crushed DBP absorption number (cDB
P) was determined according to ASTM D-3493-88. (D _mod , D _1/2 ) The maximum frequency Stokes equivalent diameter (D _mod ) and the Stokes equivalent diameter _half width (D _1/2 ) were determined as follows. Using a 20% ethanol solution as a spin solution, the Stokes equivalent diameter was measured by a centrifugal sedimentation type flow rate distribution measuring device (DCF3 type manufactured by JL Automation), and the relative occurrence frequency in the given sample relative to the Stokes equivalent diameter (FIG. 2). A line (B) is drawn from the peak (A) of the histogram to the X axis in parallel with the Y axis and ends at a point (C) on the X axis of the histogram. The Stokes diameter at point (C) is the maximum frequency Stokes equivalent diameter D _mod . Further, the midpoint (F) of the obtained line (B) is determined, and a line (G) is drawn through the midpoint (F) and parallel to the X axis. The line (G) shows the distribution curve of the histogram and 2
Intersect at points D and E. The absolute value of the difference between the two Stokes diameters at two points D and E of the carbon black particles is the Stokes equivalent diameter _half width D1 _{/ 2} value.

(PVC Blackness) The PVC blackness is determined by adding the carbon black of the present invention to a PVC resin, dispersing and sheeting with two rolls, and using a carbon black “# 40” or “# 45” manufactured by Mitsubishi Chemical Corporation. The blackness was defined as a reference value of 1 point and 10 points, respectively, and the blackness of the sample was evaluated by visual perception.

(Dispersion index) The dispersion index was evaluated by the following method. The state of dispersion in the LDPE resin was observed, and the number of undispersed aggregates was counted. The larger the number, that is, the larger the dispersion index, the worse the dispersibility was evaluated. 250c
c Using a Banbury mixer, 40% by weight of the sample carbon black is blended with the LDPE resin and kneaded at 115 ° C. for 4 minutes. Mixing conditions LDPE resin 101.89 g Calcium stearate 1.39 g Irganox 1010 0.87 g Sample carbon black 69.43 g Next, the mixture is diluted with a two-roll mill at 120 ° C. so that the carbon black concentration becomes 1% by weight.

Conditions for preparing diluted compound LDPE resin 58.3 g Calcium stearate 0.2 g Carbon black 40% blended resin 1.5 g A sheet having a slit width of 0.3 mm was cut into chips, and this sheet was cut into chips. ± 3μm
Into a film. The diameter distribution of undispersed aggregates having a diameter of 0.2 mm or more in a 3.6 mm × 4.7 mm field of view is measured with an optical microscope having a magnification of 20 ×, and the total area is calculated. This area is calculated by dividing the total area by the reference area based on the area of the undispersed aggregate having a diameter of 0.35 mm as the number of reference particles. This is observed in 16 or more visual fields, and the average value is used as the dispersion index.

(Comparative Examples 1 to 3) Under the carbon black production conditions shown in the examples, the flow rate in the choke portion was 207 m /
When s was changed to less than 250 m / s, the carbon black of Comparative Example 1 was produced under the conditions shown in Table 1, and the physical properties are shown in Table 2. Comparative Examples 2 and 3 are commercially available carbon blacks # 990 and # 960 of Mitsubishi Chemical Corporation, respectively.
Physical properties. When the obtained carbon black of the present invention is compared with a comparative example, as shown in Table 2, the example has a smaller D _1/2 / D _mod and a sharp distribution of the aggregate diameter as compared with the comparative example. In addition, it exhibits high blackness, low dispersion index,
Good dispersibility.

Example 6 Comparative Example 4 The conditions and results of the above-described computer simulation of carbon black are shown in Example 6 and Comparative Example 4 in Tables 1 and 2. Comparative Example 4 in Table 2 has a larger particle diameter than Example 6, which is considered to be because the choke inlet angle is out of the range specified in the present invention.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

As described above, the carbon black according to the present invention, when used as a black pigment in resin colorants, printing inks and paints, exhibits blackness and dispersibility, which have conventionally been in a trade-off relationship and have been considered difficult. To be satisfied. Therefore, it is very useful as a black pigment in resin colorants, printing inks and paints.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an apparatus for producing carbon black in the present invention.

FIG. 2 is a diagram showing a chalk inlet angle of a carbon black producing apparatus according to the present invention.

FIG. 3 is a diagram showing a method of obtaining a maximum frequency Stokes equivalent diameter (D _mod ) and a Stokes equivalent diameter _half width (D _1/2 ).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st reaction zone 2 2nd reaction zone 3 3rd reaction zone 4 Choke part 5 Fuel and oxidizing gas introduction nozzle 6 Feed oil introduction nozzle 7 Reaction stop fluid introduction nozzle 8 Control valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masanobu Ishida 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi Mitsubishi Chemical Corporation Yokohama Research Laboratory (72) Inventor Susumu Nakajima 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi Mitsubishi Chemical Yokohama Co., Ltd. Within the Research Institute

Claims (4)

[Claims] 1. A first combustion reaction zone for forming a high-temperature combustion gas stream, a second reaction zone having a choke section for mixing a raw material hydrocarbon with the obtained high-temperature combustion gas stream to produce carbon black, In a method for producing carbon black using a production furnace having a third reaction zone downstream of two reaction zones and stopping the reaction, the flow rate of combustion gas in the choke part is set to 250 m / s or more, and the chalk part entrance angle is 45 to 45 m / s. A method for producing carbon black, wherein the angle is set to 100 °. 2. The temperature at the feed hydrocarbon introduction position is set to 1800.
The method for producing carbon black according to claim 1, wherein the temperature is set to 2400C. 3. The method for producing carbon black according to claim 1, wherein the oxygen concentration in the combustion gas at the position where the raw hydrocarbon is introduced in the choke portion is 3 vol% or less. 4. A second reaction zone having a first reaction zone for forming a high-temperature combustion gas stream, a second reaction zone having a choke section for mixing a raw material hydrocarbon with the obtained high-temperature combustion gas stream to produce carbon black, and An apparatus for producing carbon black having a third reaction zone downstream of a reaction zone for stopping a reaction, wherein an inlet angle of a chalk portion is 45 to 100 °.