JP5530605B2 - Carbon black production furnace - Google Patents

Description

  The present invention relates to an apparatus for producing carbon black, and more specifically, an aggregate, which is a minimum dispersion unit in a matrix of carbon black measured by centrifugal sedimentation analysis, has a narrower distribution width than conventional ones. The present invention relates to a manufacturing furnace that can produce carbon black.

  Carbon black produced by the furnace method burns gaseous or liquid fuel with oxygen-containing gas (usually air) in a space lined with refractories, and generates carbonaceous feedstock in the generated hot gas stream. Introduced and pyrolyzed to produce. At this time, by appropriately adjusting various operating conditions such as the amount and position of introduction of the feedstock, the amount and position of introduction of the oxygen-containing gas and / or fuel, the quenching position, the inner diameter of the reactor, etc. Since carbon black can be produced, most are now produced by this furnace method.

  There are many types of carbon black, such as rubber reinforcing agents, colorants, and dry cell compounding agents, of which about 90% are used as rubber reinforcing agents.

  In recent years, in the tire industry, which is the main application used as a reinforcing agent, importance is placed on the environment and safety, and demands such as low fuel consumption, improved tire life, and grip performance have been further increased. Along with the improvement of rubber itself, which is the main raw material, the improvement of carbon black, which is a filling reinforcing agent, is also progressing. That is, it is necessary to control the microscopic physical properties such as the particle diameter and the size and distribution of aggregates (aggregates), not from the conventional macroscopic viewpoint of specific surface area and structure. Therefore, it is important to develop a reactor that can easily control these microscopic features.

  There is also a demand for a reactor that can increase the yield of carbon black produced by pyrolysis of raw material oil and can effectively use the thermal energy of combustion gas. In order to solve the above-mentioned problems, many techniques (patents) have been disclosed mainly regarding the shape of the reaction furnace, the operation method, and the like.

  When carbon black is compounded in a matrix such as rubber, its mechanical properties, especially tensile strength, abrasion resistance, etc. can be greatly improved compared to conventional products such as tire treads and V-belts. There is a great demand in the field of manufacturing industrial rubber compositions.

  As described above, carbon black is produced by introducing heavy feedstock into a high-temperature combustion gas stream generated by a combustion reaction between a hydrocarbon fuel and an oxygen-containing gas, and by thermal decomposition and / or incomplete combustion. The contact of this high-temperature gas stream with the feedstock oil has a great influence on the physicochemical properties of the resulting carbon black, in particular on the properties of the aggregates, as well as the size and distribution of the unit particle sizes that make up the carbon black. have.

  When carbon black is produced by the furnace method, heavy feedstock with a high carbon content is sprayed into the high-temperature combustion gas stream generated by the combustion reaction between hydrocarbons and oxygen-containing gas, and the pyrolysis of this feedstock is performed. Or carbon black produces | generates by incomplete combustion. It is well known that in the initial stage of the carbon black generation process, that is, the contact stage between the hot gas stream and the feedstock, the contact state between the two greatly affects the characteristics of the generated carbon black. An even number of substantially parallel flat side surfaces forming the inner surface of the reaction chamber having a polygonal cross section, and by introducing a plurality of hydrocarbon sprays into the reaction chamber every other one from the flat side surfaces, a cross-sectional area of the hot gas flow A manufacturing furnace is disclosed in which a cross section is formed so as to coincide with the cross section of the spray pattern so as to maximally cover the surface with hydrocarbon spray (Patent Document 1).

  In addition, even if the feed oil introduction space becomes large, the applicant of the present application has selected a non-circular and non-polygonal shape as the shape of the introduction space in order to control the width of the aggregate distribution of the generated carbon black to the smaller side. The carbon black manufacturing apparatus which has is proposed (patent document 2).

  The idea in these prior arts is how efficiently the energy of the high-temperature combustion gas flow generated in the first combustion zone is transferred to the spray raw material flow from the raw material introduction means provided in the reaction zone. The issue was whether to give or contact.

  On the other hand, as a means for narrowing the aggregate distribution of carbon black, it is also effective to reduce the area in the space where the feedstock oil is introduced.

  However, the introduction of a combustion gas flow into a narrow space results in a pressure increase, which results in a defect that the flow rate of the combustion gas flow is limited. This is a very large limitation in the carbon black production process, and the above-described adjustment range of the aggregate distribution is limited.

Japanese Patent Publication No. 7-74315 JP 2006-111643 A (Patent No. 3859057)

  It is an object of the present invention to produce carbon black characterized in that the distribution width of the aggregate, which is the minimum dispersion unit in the matrix, measured by centrifugal sedimentation analysis has a characteristic smaller than that of the conventional one. To provide a furnace. With this furnace, the distribution width of the aggregate can be reduced, and the reinforcement performance to the rubber can be further improved. As a result, further merit can be derived by reducing the blending ratio to the rubber. .

The first of the present invention is a first zone provided with each introducing means for generating a high temperature gas stream by combustion of a mixture of hydrocarbon fuel and oxygen-containing gas, in the high temperature gas stream generated in the first zone. A second cylindrical reaction zone provided with a raw material introduction means for supplying raw material hydrocarbons in a plurality of divided flows to form a carbon black-containing reaction gas flow by thermal decomposition and / or incomplete combustion of the raw material hydrocarbons A zone and a third zone having a cylindrical shape larger than the diameter of at least the second zone provided with a cooling water spraying device for spraying cooling water to the reaction gas flow from the second zone to stop the reaction. in overall carbon black production furnace is placed horizontally, provided with a plurality of outer peripheral flow space over the cylindrical direction coaxial entire area of the reaction zone on the outer circumference of the cylindrical reaction zone of the second band, and, the outer peripheral flow space About the carbon black production furnace, characterized in that it said material introducing means is provided in the gap.
A second aspect of the present invention relates to the carbon black production furnace according to claim 1, wherein the number of the raw material hydrocarbon introduction means and the number of the outer peripheral flow spaces are the same.
The third aspect of the present invention is the production of carbon black according to claim 1 or 2, wherein the ratio of the total area of the plurality of outer peripheral flow spaces to the area of the cylindrical reaction zone as the second zone is 0.2 to 0.5. Related to the furnace.
The fourth aspect of the present invention is the carbon black production furnace according to any one of claims 1 to 3, wherein the ratio of the diameter of the outer peripheral flow space to the diameter of the cylindrical reaction zone which is the second zone is 1.2 to 1.8. About.
5th of this invention is related with the carbon black manufacturing furnace in any one of Claims 1-4 whose diameter of the said outer periphery flow space and the diameter of the said 3rd cylindrical zone are the same.

  The inventors conducted research to take advantage of the narrowness of the aggregate distribution in the narrow space when the raw material was introduced, and set up another space outside the narrow space that was not in contact with the raw material oil spray flow. As a result, the present inventors have found that the aggregate distribution can be controlled to the narrow side and have completed the present invention.

  In the present invention, the ratio (S2 / S1) of the sum (S2) of the plurality of outer peripheral flow spaces to the area (S1) of the cylindrical zone is 0.2 to 0.5, preferably 0.2 to 0.3. And the ratio (d2 / d1) of the diameter (d2) of the outer peripheral flow space to the diameter (d1) of the cylindrical zone is 1.2 to 1.8, preferably 1.2 to 1.5. desirable. When the ratio is below the lower limit in any ratio, a clear difference from the case of not installing the outer peripheral flow space does not appear, and conversely, when the upper limit is exceeded, the contact between the high-temperature combustion gas flow and the feed oil spray flow The efficiency is greatly reduced, making it difficult to control the reaction conditions, that is, the aggregate distribution, and the carbon recovery efficiency is also lowered.

  As described above, the reason why the distribution of the aggregate can be narrowed by forming the flow space on the outer periphery of the feed oil introduction space is that the reaction temperature of the high temperature gas flow decreases due to the carbon formation reaction when it contacts the feed oil flow. However, the energy of the high-temperature gas flow from the outer space is supplied so as to surround the reaction product to compensate for the temperature decrease, and the pyrolysis reaction is promoted, so that the carbon formation reaction is made uniform. It is estimated that the narrowing of the distribution was achieved.

  In the following examples, carbon black was produced using the production furnace of the present invention. It can be seen that carbon black having a narrow aggregate distribution (small D50 and D50 / Dst) can be obtained while the production amount is substantially equal when compared with this example and the reference example. This means that, when the production amount is maintained, it is possible to produce carbon black with higher performance than before and to further expand the physical property control range. In general, the production volume and the aggregate distribution are linked items, and it has been known that the aggregate distribution increases when the furnace volume (cross-sectional area) is increased to increase the production volume. By using this manufacturing furnace, it is possible to increase the production volume by increasing the cross-sectional area while maintaining the same aggregate distribution as that of the conventional carbon black.

Next, examples of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited thereto.
FIG. 1 is a longitudinal sectional view of an apparatus showing an example suitable for carrying out the present invention, FIG. 2 is a sectional view taken along the line PP in FIG. 1, and FIG. 3 is a view taken along the line QQ in FIG. FIG. FIG. 4 is a sketch showing the internal space of the carbon black production furnace of the present invention having a plurality of flow spaces on the outer periphery of the cylindrical zone, and FIG. 5 is a sketch of a conventional production furnace having no flow space on the outer periphery. is there. In addition, since the space | planar drawings 4 and 5 in the manufacturing furnace 1 become complicated, only 9B-1 to 9B-4 were displayed for the raw material introduction apparatus.

  A cylindrical flammable fluid introduction chamber 2 is provided at the upstream end of the carbon black production furnace 1 using the axial flow of FIG. 1, and a rectangular combustion holding oxygen-containing gas introduction pipe is provided outside the introduction chamber 2. 3 is connected. Inside the introduction chamber 2, there is an oxygen-containing gas introduction cylinder 4 that is coaxial and has a downstream end that coincides with the introduction chamber 2 and is shorter than the introduction chamber 2. A rectifying plate 5 for rectifying the flow of the oxygen-containing gas is installed on the outer periphery. The rectifying plates 5 are preferably installed at an equal angle, preferably 10-20 (refer to the applicant's Japanese Patent Application Laid-Open No. 4-264165 for this point). In addition, a fuel introduction pipe (not shown) is provided on the central axis of the introduction chamber 2 and the cylinder 4 through a fuel introduction space 6.

  As shown in FIG. 1, a converging chamber 7 for gradually converging the combustion gas flow is connected to the downstream side of the introduction chamber 4. On the downstream side, a raw material oil introduction chamber 10 having an annular cross-sectional shape in which a plurality of raw material oil spraying devices 9 (for example, 9B-1 to 9B-4) shown in FIGS. 3 and 4 are installed is connected. However, the same flow space 11 (for example, 11-1 to 11-4) as the number of spraying devices is formed in the space where the spraying device 9 is not installed in the outer periphery of the introduction chamber 10 (see FIG. 2A-A arrow view and sketch of FIG. 4). On the downstream side of the second zone 8 formed by the cylindrical raw material oil introduction chamber 10 and the outer peripheral flow space 11, the reaction is stopped by quenching the carbon black reaction gas flow (a plurality of cooling water spray devices a to h are installed). The reaction continuation / cooling chamber 12 is connected. Although the size of the reaction continuation / cooling chamber is arbitrary, the upstream end of the reaction continuation / cooling chamber 12 has a flow space 11 in order to reduce the influence on the turbulence in the flow of the reaction product flowing out from the second zone. It is desirable to be the same as the diameter. In the reaction continuation and cooling chamber 12, a to h are provided with a plurality of cooling water spray devices disclosed in Japanese Utility Model Publication No. 58-140147 (Applicant: Asahi Carbon Co., Ltd.). The chamber 12 and the flue 13 are connected. Although the size of the reaction continuation / cooling chamber is arbitrary, it is at least larger than the raw material oil introduction chamber 10, and the upstream end of the zone 12 reduces the influence on the turbulence in the flow of the reaction product flowing out from the second zone. In order to achieve this, it is desirable that the diameter is the same as the diameter including the feed oil introduction chamber 10 and the flow space 11. Further, as the spraying device 9, the device disclosed by the applicant of the present invention in Japanese Patent Application Laid-Open No. 2004-59598 was used and installed on the operating surface of the raw material oil introduction chamber 10.

Production Example 1
SAF grade carbon black was manufactured using a carbon black manufacturing apparatus having the same configuration as that shown in FIGS. 1, 2, 3 and 4. Each component of this manufacturing apparatus was as follows.
Flammable fluid introduction chamber 2
Inner diameter 650mmφ; Length 600mm
Oxygen-containing gas introduction pipe 3 (rectangular)
Long side 400mm; Short side 200mm
Oxygen-containing gas cylinder 4
Inner diameter 450mmφ; Length 500mm
Combustion chamber 7
Inner diameter: upstream end 595 mmφ; downstream end 160 mmφ
Length 1700mm; Convergence angle 7.3 °
Second band 8
Raw material oil introduction room 10
Inner diameter (d1) 160mmφ; Length 600mm
Cross-sectional area [S1 = (d1 / 2) ² π] 201 cm ²
Peripheral flow space 11-1 to 11-4
Inner diameter (d2) 230mmφ; Width (d3) 40mm
Cross-sectional area [S2 = (d2-d1) × 1/2 × d3 × 4] 56 cm ²
Diameter ratio (d2 / d1) 1.44; Area ratio (S2 / S1) 0.28
(All ratios when the material introduction chamber 10 is 1)
Reaction continuation / cooling chamber 12
Inner diameter 230mmφ; Length 1500mm
In this embodiment, an example in which 9A (upstream end is 200 mm) and 9B (upstream end is 400 mm) in the second zone 8 is shown as the space where the raw material introduction apparatus is installed, but the aggregate size distribution is narrow. In the production of the carbon black of the present invention, good results can be obtained by using either one of the spaces, but the use of 9B on the downstream side tends to be a narrower product. It is done. In both Examples and Comparative Examples, 9B was used as the feed oil spray space.

  A heavy oil having a specific gravity of 0.8622 (15 ° C./4° C.) was used as the fuel oil, and a heavy oil having the properties and composition shown in Table 1 was used as the feed oil.

Production Example 2
Carbon black was manufactured using a manufacturing furnace having the same structure as that of the manufacturing apparatus of Manufacturing Example 1 except that the second zone 8 was changed to the following structure.
Second band 8
Raw material oil introduction room 10
Inner diameter (d1) 180mmφ; Length 600mm
Cross-sectional area (S1) 254 cm ²
Peripheral flow space 11-1 to 11-4
Inner diameter (d2) 230mmφ; Width (d3) 60mm
Cross-sectional area (S2) 60 cm ²
Diameter ratio (d2 / d1) 1.28; Area ratio (S2 / S1) 0.24
(Both ratios where the feedstock introduction chamber 10 is 1)

Comparative Example 1
Although it has the same structure as the production furnace of Production Example 1, it is a production furnace having an inner cylindrical shape with an inner diameter of 160 mmφ that does not have the outer peripheral flow spaces 11-1 to 11-4 only in the second zone, that is, the space 11 in FIG. SAF grade carbon black was produced using a production furnace having the structure shown in FIG.
Second band 8
Raw material introduction room 10
Inner diameter (d1) 160mmφ; Length 600mm
Cross-sectional area (S1) 201 cm ²
Reaction continuation / cooling chamber 12
Inner diameter 230mmφ; Length 1500mm
In addition, the raw material oil spraying apparatus (9-1 to 9-4) was installed in the middle part of zone 8 (300 mm from the upstream side).

Comparative Example 2
Except using the manufacturing furnace reaction zone of a cylindrical shape having an inner diameter of 180mmφ having substantially equal cross-sectional area as the cross-sectional area of the band 8 (composed of the cylindrical portion and the peripheral flow space) in manufacturing Zorei 1 and Comparative Example 1 SAF grade carbon black was produced using the same equipment .
Second band 8
Raw material introduction room 10
Inner diameter 180mmφ

Reference example 1
Although it is the same structure as the manufacturing furnace of the manufacture example 1, the diameter ratio and area ratio of the outer periphery flow space 11-1 to 11-4 with respect to the raw material oil introduction chamber 10 of cylindrical space in the 2nd zone are the manufacture examples 1 and 2. Changed to a different device to produce carbon black.
Second band 8
Raw material oil introduction room 10
Inner diameter (d1) 160 mmφ; sectional area (S1) 201 cm ²
Peripheral flow space 11-1 to 11-4
Inner diameter (d2) 300mmφ; Width (d3) 40mm
Cross-sectional area (S2) 112 cm ²
Diameter ratio (d2 / d1) 1.88; Area ratio (S2 / S1) 0.56
(Both ratios where the feedstock introduction chamber 10 is 1)

Reference example 2
In the production furnace of Reference Example 1, the width of the outer peripheral flow spaces 11-1 to 11-4 was set to 20 mm, and the area ratio with respect to the raw material oil introduction chamber 10 was changed to the same apparatus as in Production Example 1 to produce carbon black.
Peripheral flow space 11-1 to 11-4
Inner diameter (d1) 300mmφ; Width (d3) 20mm
Cross-sectional area (S1) 56 cm ²
Diameter ratio (d2 / d1) 1.88; Area ratio (S2 / S1) 0.28
(Both ratios where the feedstock introduction chamber 10 is 1)

Reference example 3
Although it is the same as the manufacturing furnace of the manufacture example 1, the width of the outer periphery flow space 11-1 to 11-4 is set to 80 mm, and the area ratio with respect to the raw material oil introduction chamber 10 is different from the manufacture examples 1 and 2. Carbon black was produced.
Second band 8
Raw material oil introduction room 10
Inner diameter (d1) 160 mmφ; sectional area (S1) 201 cm ²
Peripheral flow space 11-1 to 11-4
Inner diameter (d2) 230mmφ; Width (d3) 80mm
Cross-sectional area (S2) 112 cm ²
Diameter ratio (d2 / d1) 1.44; Area ratio (S2 / S1) 0.56
(Both ratios where the feedstock introduction chamber 10 is 1)

The diameter ratios and area ratios in the cylindrical band 10 and the outer peripheral flow space 11 in the band 8 in Production Examples 1 and 2, Comparative Examples 1 and 2 and Reference Examples 1 to 3 are summarized as follows.

  Using the various production furnaces described above, SAF grade carbon black was produced under the production conditions described in the following table. The carbon black properties at this time are also shown in Table 4.

Each characteristic of the carbon black shown in the table is measured as follows.
(1) CTAB adsorption specific surface area (CTAB)
It is measured by the method described in Item D method of JIS K 6217: 1997, and is expressed as a specific surface area m ² / g per unit weight.
(2) 24M4DBP absorption (CDBP)
It is measured by the method described in Item 10 of JIS K 6217: 1997, and is expressed in ml of dibutyl phthalate (DBP) absorbed per 100 g of carbon black.
(3) Analysis method of carbon black aggregate size by centrifugal sedimentation analysis Measuring device: High-speed disc centrifugal ultrafine particle size analyzer (measurement device name: BI-DCP, manufactured by BROKHAVEN INSTRUMENTS CORPORATION)
Measuring method: Carbon black sample dried according to JIS K 6218 was added with a small amount of surfactant (Nonidet P-40), kneaded into a paste, mixed with 20 vol% ethanol aqueous solution, and carbon black concentration 200 mg / 1 dispersion is prepared and sufficiently dispersed with an ultrasonic homogenizer to prepare a sample.
The rotation speed of the apparatus is set to 8000 rpm, 10.0 ml of spin solution (pure water, 24 ° C.) is added, and then 1.0 ml of buffer solution (20 vol% ethanol aqueous solution, 24 ° C.) is injected. Subsequently, 0.5 ml of carbon black dispersion liquid at 24 ° C. is injected to start measurement. The Stokes equivalent diameter corresponding to each time t is calculated by the formula (1) from the elapsed time after adding the carbon black dispersion and the absorbance distribution curve.
[Equation 1]
D = {[18η1n (Rd / Ri)] / ω ² Δρt} ^1/2 (1)
In equation (1), η is the viscosity of the solvent (mPa · S), ω is the disk rotational speed (rpm), Δρ is the density difference between the carbon black particles and the solvent (g / cm ³ ), Ri is the carbon black dispersion injection The radius of the point (cm), Rd is the radius to the absorbance measurement point (cm), and t is the time (minutes). The terms “radius of the dispersion injection point and radius to the absorbance measurement point” will be described below. Since this measuring device is rotating at high speed, the injected liquid is filled from the outside of the device container. Accordingly, the radius of the liquid spreading surface when the dispersion is injected becomes the radius Ri of the dispersion injection point. In addition, the aggregate settles in the spin liquid due to centrifugal force, and the distance between the point at which the precipitate concentration is measured after a predetermined time has passed and the rotation center point is the radius Rd to the absorbance measurement point. Specifically, it is the same as that described in JP-A-8-169983.

Definition of mode diameter (Dst) and half-value width (D50) of distribution curve The Stokes equivalent diameter at the most frequent value in the distribution curve is defined as Dst mode diameter (nm), and two large and small points corresponding to 50% frequency of the most frequent value The difference (half-value width) of the Stokes equivalent diameter is defined as D50 (nm).

It is a cross-sectional view of an apparatus showing an example suitable for carrying out the present invention. It is sectional drawing in the PP arrow in the 2nd zone | band 8 which has not installed the raw material oil spraying apparatus 9 of FIG. It is sectional drawing of the QQ arrow in the 2nd zone | band 8 which has installed the raw material oil spraying apparatus 9 of FIG. It is the sketch which showed the internal space of this invention carbon black manufacturing furnace. It is a sketch of the conventional manufacturing furnace which does not have a fluid space on the outer periphery.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carbon black production furnace 2 Flammable fluid introduction chamber 3 Oxygen containing gas introduction pipe 4 Oxygen containing gas introduction cylinder 5 Current plate 6 Space for fuel introduction pipe 7 Converging chamber 8 Second zone 9A Raw material oil spraying device 9B Raw material oil spraying device 9B -1 Raw material oil spraying device 9B-2 Raw material oil spraying device 9B-3 Raw material oil spraying device 9B-4 Raw material oil spraying device 10 Raw material oil introduction chamber 11-1 Outer peripheral flow space 11-2 Outer peripheral flow space 11-3 Outer peripheral flow space 11-4 Outer peripheral flow space 12 Reaction continuation and cooling chamber 13 Flue a Cooling water spraying device b Cooling water spraying device c Cooling water spraying device d Cooling water spraying device e Cooling water spraying device f Cooling water spraying device g Cooling water spraying device h Cooling water spray device

Claims (5)

A first zone having each introduction means for generating a high temperature gas stream by combustion of a mixture of hydrocarbon fuel and oxygen-containing gas, and dividing the raw hydrocarbon into a plurality of the high temperature gas streams generated in the first zone A second reaction zone, which is a cylindrical reaction zone provided with a raw material introduction means for supplying the raw material hydrocarbons into a carbon black-containing reaction gas flow by thermal decomposition and / or incomplete combustion of the raw material hydrocarbons. A horizontally placed carbon composed of a third zone with a cylindrical shape larger than the diameter of at least the second zone, provided with a cooling water spray device for spraying cooling water on the reaction gas flow to stop the reaction in black production furnace, comprising a plurality of outer peripheral flow space over the cylindrical direction coaxial entire area of the reaction zone on the outer circumference of the cylindrical reaction zone of the second zone, and the material in the gap between the outer peripheral flow space Carbon black production furnace, wherein a guide means is provided.   The carbon black production furnace according to claim 1, wherein the number of the raw material hydrocarbon introduction means and the number of the outer peripheral flow spaces are the same.   The carbon black production furnace according to claim 1 or 2, wherein a ratio of a total area of the plurality of outer peripheral flow spaces to an area of the cylindrical reaction zone which is the second zone is 0.2 to 0.5.   The carbon black production furnace according to any one of claims 1 to 3, wherein a ratio of a diameter of the outer peripheral flow space to a diameter of the cylindrical reaction zone which is the second zone is 1.2 to 1.8.   The carbon black production furnace according to any one of claims 1 to 4, wherein a diameter of the outer peripheral flow space and a diameter of the third cylindrical zone are the same.