JPH11181321A - Carbon black production equipment and manufacture of carbon black - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the heat-release amount, to facilitate the replacement of a diffuser portion during temperature rise, and to prevent the damage of bricks of a combustion portion without melting the tip portion of a combustion burner by employing a combustion burner having a cooling jacket in a carbon black production unit comprising a combustion portion, a reaction portion and a reaction termination portion. SOLUTION: The combustion burner comprises a cooling jacket 21, a cooling medium inlet nozzle 22, a cooling medium outlet nozzle 23, a diffuser portion 24, a tapered portion 24-1, a support gas spray hole 24-2, a combustion gas spray hole 24-3, a flange 25, an O-ring 26, a fastener screw 27, a diffuser compression spring 28, a fuel introduction pipe 29, a fuel introduction flange 210 and a support gas introduction nozzle 211. A material for a double pipe and the diffuser portion is one having a good thermal conductivity (a thermal conductivity of 10 kcal/mhr deg.C or more). The double pipe and the diffuser portion are provided with temperature sensors such as a thermocouple. The connecting portion between an outer cylinder of the cooling jacket and the diffuser portion are made tapered surface (at an angle of 60 deg. or less).

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 relates to a new and useful combustion apparatus. More specifically, the present invention relates to a combustion device capable of exhibiting an effect of stably obtaining a high-temperature atmosphere in a reaction section.

[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. The oxygen-containing gas and the fuel are introduced in the direction, and the high-temperature combustion gas flow obtained by these combustions is successively moved to a reaction section having a reduced cross-sectional area installed in the furnace axis direction while the gas flows. 2. Description of the Related Art A furnace-type production method in which a raw material hydrocarbon is introduced into a stream to generate carbon black, and a reaction gas is rapidly cooled in a reaction stopping portion 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] In order to obtain carbon black having a small particle size, a raw material hydrocarbon is first sprayed into a high-speed gas stream in a choke section in a reaction section, and the motion and heat energy of the gas are atomized into a liquid feedstock. It is effective to utilize the heat energy of the high-temperature combustion gas efficiently for the reaction of carbon black generation by turbulent mixing in the reaction section.

[0005] There are various types of combustion burners in a carbon black production furnace, and high-temperature metals such as high-temperature stainless steel are generally used as materials. It was possible to use even in an oxidizing atmosphere such as manufacturing.

[0006]

[Problems to be solved by the present invention]
At a temperature higher than 0 ° C., such a combustion burner conventionally used in a carbon black producing apparatus has
It has been found that problems such as burner damage due to melting and thermal strain are likely to occur and are very dangerous. For example, Shoko Sho 4
Japanese Patent Application Laid-Open No. 4-31926 discloses a carbon black production furnace having a structure in which a refractory material has a fuel hole and a supporting gas hole and is diffused and burned in a combustion chamber. It is difficult to use above the heat resistant temperature of Some heat-resistant materials are considered to be able to withstand temperatures of 2000 ° C. or higher (for example, zirconia-based refractory materials, magnesia-chrome-based refractory materials, magnesia-based refractory materials, etc.), but when heated in a highly oxidizing atmosphere such as a carbon black production furnace. The problem of heat shock due to temperature change at the time of temperature drop, and the problem of breakage of the refractory material due to erosion by high-speed gas flow occurs when the fuel holes and the supporting gas holes are made of refractory material, making it difficult to put into practical use. I understood.

An object of the present invention is to provide a combustion burner and a production apparatus capable of withstanding the production of carbon black using a high-temperature gas.

[0008]

Means for Solving the Problems In view of the above problems, the present inventors have made intensive studies. As a result, by using a combustion burner having a specific structure to generate combustion gas, the primary particle diameter is small, the aggregate diameter is small, the width of the aggregate distribution is small, and the large aggregate system is excellent. The inventors have found that it is possible to obtain carbon black having characteristics, and have reached the present invention.

That is, the present invention provides a combustion burner for producing carbon black, which has a cooling jacket structure, a method for producing carbon black using the same,
The present invention also relates to a carbon black producing apparatus comprising a combustion section, a reaction section, and a reaction stopping section, characterized by having a combustion burner having a cooling jacket structure.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The present invention uses an apparatus having a specific structure as a combustion burner in an apparatus for producing carbon black comprising a combustion section, a reaction section, and a reaction stop section. The apparatus for producing carbon black itself comprising a combustion section, a reaction section, and a reaction stop section is a known apparatus, and a known technique can be appropriately selected. For example, a manufacturing apparatus can be configured as shown in FIG. In the figure, 11 is a combustion section, 12 is a reaction section, 1
Reference numeral 3 denotes a reaction stopping portion, 14 denotes a combustion burner, 15 denotes a feed oil introducing nozzle, and 16 denotes a reaction stopping fluid introducing nozzle.

In the present invention, the combustion burner has a cooling jacket structure. FIG. 2 shows a schematic view of an example of a combustion burner having the cooling structure of the present invention. In the figure, 21 is a cooling jacket, 22 is a cooling medium inlet nozzle, 23 is a cooling medium outlet nozzle, 24 is a diffuser part, 24-1 is a tapered part, 24-2 is a supporting gas spray hole, and 24-3 is a combustion gas. Spray hole, 25 is flange, 2
6 is an O-ring, 27 is a fixing screw, 28 is a diffuser pressing spring, 29 is a fuel introduction pipe, 210 is a fuel introduction flange, and 211 is a supporting gas introduction nozzle.

The cooling jacket has a cylindrical double-pipe structure provided outside the combustion gas introduction pipe of the combustion burner. The combustion diffuser section is in contact with the inside of the double pipe, and the combustion diffuser section is also cooled. It has a structure that can be performed. It is preferable to use a material having good thermal conductivity as the material of the double pipe and the diffuser portion. Here, the good heat conductive material refers to a material having a heat conductivity of 100 kcal / mhr ° C. or more, and specifically, copper, a copper alloy, aluminum or the like. There is no problem even if another structural member is used for a portion of the cooling jacket facing the inside of the furnace and having a high temperature. The cooling jacket has a double pipe structure, and has a structure capable of cooling the combustion burner by flowing a cooling medium in a direction indicated by an arrow in the figure.

If a measuring device such as a thermocouple capable of detecting a temperature is installed in the double pipe and the diffuser portion, the cooling state of the tip of the combustion burner can be grasped, and stable operation can be performed. Further, by grasping the temperature in this way, the amount of the cooling medium can be adjusted and the optimum operation can be performed. In other words, in order to obtain high temperatures, it is necessary to minimize the amount of heat radiation,
Operating with a minimum amount of cooling medium is a means of maintaining high temperatures.

Since it is generally difficult to operate from a low temperature to a high temperature range using one combustion burner, it is preferable to raise the temperature to a high temperature range using two or more combustion burners. Such an embodiment is made possible by replacing the diffuser with a dedicated diffuser for each temperature range. At this time, since the inner surface of the outer cylinder of the cooling jacket and the outer peripheral surface of the diffuser are in contact with each other, heat is exchanged efficiently, and the tip portion in contact with the high-temperature atmosphere is cooled. If the contact surface has a positional relationship parallel to the axial direction of the furnace, it is difficult to pull out the diffuser. This is due to the fact that by adjusting the size of the inner diameter of the outer jacket of the cooling jacket and the outer diameter of the diffuser part, the two member surfaces are brought into contact by thermal expansion, but this contact surface is tapered. This makes it possible to easily replace the combustion burner even at a high temperature. There is no problem if the taper angle is 60 degrees or less. Preferably 1 to 10 degrees is good.

A spring for pressing the diffuser is used in order to always maintain good contact between the diffuser and the tapered portion at the tip of the cooling jacket. This pressing force may be any means as long as it has the same function as the spring shown in FIG. The sealing structure of the flange portion may be any method as long as it has a sealing property equivalent to that of the O-ring. For example, there is no problem if a ground box structure using a gland packing is used to maintain the sealing property.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. (Example 1) As shown in FIG. 1, a combustion section having an inner diameter of 500 mm and a length of 1400 mm equipped with a combustion burner having a cooling structure, an inner diameter of 60 mm connected to the combustion section and having a plurality of raw material nozzles penetrating from the periphery and having a length of 60 mm Reaction section with 800 mm choke, 100 mm inner diameter with quench device,
A carbon black production furnace consisting of a 6000 mm long reaction stop was installed.

The position of the raw material nozzle is 100 mm from the entrance of the choke section. Using the above furnace, carbon black was produced under the conditions shown in Table 1. Fuel and
Creosote oil was used as the starting hydrocarbon. In Examples 3 and 4, oxygen was added to air to increase the combustion temperature. In Table 1, "combustion gas temperature", "combustion gas oxygen concentration", and "furnace pressure" are those at the site where the raw material 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 resulting carbon black. (Specific surface area) The specific surface area (N ₂ SA) is ASTM D-3.
037-88. (CDBP) Destructive DBP absorption number (cDBP) is ASTM
Determined according to D-3493-88. (D _mod , D _1/2 ) The maximum frequency equivalent stalk diameter (D _mod ) and the _half equivalent stalk diameter (D _1/2 ) were determined as follows.

Using a 20% ethanol solution as a spin solution, a Stokes equivalent diameter was measured by a centrifugal sedimentation type particle size distribution analyzer (DCF3 type manufactured by JL Automation), and the Stokes equivalent diameter was compared with the relative diameter in the given data. A histogram of the target occurrence frequency (FIG. 3) is created. 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 ).

A 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. Line (G) shows the distribution curve of the histogram and two points D and E.
Meet at The absolute value of the difference between the two Stokes diameters at the two points D and E of the carbon black particles is the Stokes equivalent radius width D _1/2 value. (D ₇₅ ) The 75% volume diameter (D ₇₅ ) was determined as follows.

In the above method of determining the maximum frequency Stokes diameter, a histogram of the equivalent Stokes diameter vs. the relative frequency of occurrence of the data. From FIG. 3, the volume was determined from each Stokes diameter and frequency. Create a graph showing the total volume of the material (Fig. 4). Therefore, the middle point (A) in FIG. 3 represents the sum of the volumes of all the materials. Here, a point (B) having a value of 75% of the total volume is determined,
Draw a line from point (B) parallel to the X axis until it intersects the curve.
A line is drawn parallel to the Y axis from the point (C), and the value at the point (D) crossing the X axis is the volume 75% diameter ( _D75 ). (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 Mitsubishi Chemical Corporation carbon black “# 40”
The blackness of “# 45” was determined to be 1 point and 10 points, respectively, and the blackness of the material was evaluated by visual perception. (Dispersion index) The dispersion index was evaluated by the following method. LD
The state of dispersion in the PE 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.

LDP with 250cc Banbury mixer
40% by weight of material carbon black is mixed with E resin,
Knead at 15 ° C for 4 minutes. Compounding conditions LDPE resin 101.89 g Calcium stearate 1.39 g Irganox 1010 0.87 g Material 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.

Diluting compound preparation conditions LDPE resin 58.30 g Calcium stearate 0.20 g Carbon black 40% blended resin 1.50 g A sheet with a slit width of 0.3 mm, cut into chips, and cut on a hot plate at 240 ° C. for 65 ± 3μm
Into a film. The diameter distribution of undispersed aggregates having a diameter of 0.2 mm or more in a 3.6 × 4.7 mm visual field is measured with an optical microscope having a magnification of 20 ×, and the area thereof 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.

The productivity at the same particle diameter or the same PVC blackness is as follows:

[0025]

[Formula 1] It can be expressed by feedstock feedstock feedstock yield / air quantity, and the fuel consumption ratio becomes lower as the total carbon yield becomes higher. (Particle size) According to electron microscopy. Electron microscopy is a method described below.

After carbon black is charged into chloroform and irradiated with 200 KHz ultrasonic wave for 20 minutes to disperse,
The dispersion material is fixed to the supporting 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 1500 times, and the values are obtained by arithmetic averaging.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

According to the present invention, it is possible to obtain a high-temperature combustion gas without causing the tip of the combustion burner to be melted, and to obtain a high-temperature combustion gas while minimizing the amount of heat radiation from the combustion burner. It became. Further, the diffuser portion can be easily replaced at the time of temperature rise, and the replacement can be completed in a short time. Therefore, heat shock due to rapid cooling of the brick in the burning portion does not occur, and brick damage can be prevented.

Therefore, according to the present invention, it is possible to stably supply carbon black which satisfies blackness and dispersibility and is very useful as a black pigment in resin colorants, printing inks and paints.

[Brief description of the drawings]

FIG. 1 is a carbon black production furnace equipped with a combustion burner having a cooling structure used in Example 1.

FIG. 2 is a schematic view showing an example of a combustion burner having a cooling structure according to the present invention.

FIG. 3 is a histogram of Stokes equivalent diameter vs. relative occurrence frequency of data in an example.

FIG. 4 is a graph showing Stokes diameter versus total volume of material obtained to that diameter in an example.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Fukuyama 1-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu Mitsubishi Chemical Co., Ltd. Kurosaki Works (72) Inventor Nobutake 1-1 Takeshi Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu City Mitsubishi Chemical Corporation Kurosaki Office

Claims (9)

[Claims] An apparatus for producing carbon black comprising a combustion section, a reaction section, and a reaction stop section, comprising a combustion burner having a cooling jacket structure. 2. The carbon black producing apparatus according to claim 1, wherein the tip of the combustion burner is formed of a good heat conductive member. 3. The carbon black producing apparatus according to claim 1, further comprising a mechanism capable of detecting a temperature at a tip portion of the combustion burner. 4. The carbon black producing apparatus according to claim 1, wherein a tip of the combustion portion in contact with the cooling jacket portion of the combustion burner has a tapered shape and has a structure capable of being extracted. 5. A combustion burner for producing carbon black, having a cooling jacket structure. 6. The combustion burner for producing carbon black according to claim 5, wherein the tip is formed of a good heat conductive member. 7. The combustion burner for producing carbon black according to claim 5, further comprising a mechanism capable of detecting a temperature at a tip portion. 8. The combustion burner for producing carbon black according to claim 5, wherein the tip of the combustion portion in contact with the cooling jacket has a tapered shape and has a structure capable of being extracted. 9. A method for producing carbon black, comprising a step of introducing a fuel from the combustion burner for producing carbon black according to claim 5 to form a high-temperature atmosphere.