JPS59204665A - Method and apparatus for producing furnace carbon black and giving electrically conductive carbon black as by-product - Google Patents

Abstract

PURPOSE:To produce electrically conductive carbon black (CB) economically as a by-product of furnace CB, by contacting hot gas stream suspending CB produced by furnace process with a cold wall thereby depositing electrically conductive CB on the wall surface, and collecting the furnace CB from the residual gas stream. CONSTITUTION:The gas stream suspending carbon black produced by the thermal cracking of stock oil in the cracking furnace, is cooled with water sprayed through the spray nozzle 4 for quenching, and introduced through the line 9 to the bottom of the cooling reaction column 5. The introduced hot suspension of carbon black is transferred upward while being brought into contact with the cold reaction column wall cooled by the function of the cooling jacket 6, and electrically conductive fine carbon black particles having developed chain structure are deposited on the cooled wall surface. The remaining carbon black stream transferred to the top of the cold reaction column 5 is introduced through the line 10 into the collection system such as bag filter, etc. and collected as the furnace carbon black of normal grade.

Description

Detailed Description of the Invention Acetylene black has been known for a long time as a type of carbon black that has electrical conductivity, and recently, by-product carbon black produced during the production of synthetic raw material gas has been used as a carbon black with or without a small amount of oxygen. Heat treatment under active atmosphere (approximately 3
00 to 900°C) are useful, but these have the disadvantage of raising production costs in terms of raw materials and manufacturing processes.

The present invention provides a novel method and apparatus for co-producing conductive carbon black at low cost during the process step of manufacturing conventional 7 Arness carbon black.

That is, the manufacturing method of the present invention is characterized by bringing a high-temperature carbon black suspended gas flow generated by a furnace method into contact with a cooling wall to precipitate conductive carbon black on the wall surface, and removing excess carbon black from the surplus carbon black suspended gas flow. It consists of the process of collecting ordinary types of carbon black using conventional methods.

Below, the manufacturing method and apparatus of the present invention are illustrated in the manufacturing equipment diagram (first
The explanation will be based on Figure).

In the figure, 1 is a regular cylindrical generating furnace constructed with a cover made of refractory material and steel, with a combustion burner and a nozzle 2 for material injection at the head of the furnace, and an air introduction duct 3 extended in the tangential direction. , and has a structure equipped with a quenching spray nozzle 4 in the downstream region. 5 is a cooling reaction tower having an air cooling jacket 6 on the outside, a scraper device 7 inside, and a hopper section 8 at the bottom. The cooling reaction tower 5 is connected to the downstream end of the generating furnace 1 via a conduit 9, and has a mechanism in which a high-temperature carbon black suspended gas stream flows upward while contacting the cooled inner wall surface. are doing. A conduit 10 is connected to the upper part of the cooling reaction tower 5,
It is connected to a collection bag filter device (not shown). Further, the lower end of the hopper part 8 is connected via a rotary feeder 15 to a screw conveyor 14 that communicates with a crusher and a storage tank (not shown).

The cooling reaction tower 5 may be provided alone, but for continuous operation, a plurality of these may be installed as shown in the figure, and the flow switching pulp 11.12 of the carbon black suspended gas flow interposed in the conduits 9 and 10 is used. It is desirable to design the structure so that it can be operated alternately by operating the

In the apparatus having the above structure and mechanism, the generator l
The carbon black suspended gas stream generated by the thermal decomposition reaction of the feedstock oil is cooled to below 850° C. by water spraying from the quenching spray nozzle 4, and then introduced into the lower part of the cooling reaction tower 5 through four pipes 9. The introduced high-temperature carbon black suspended gas flow rises while contacting the inner wall of the cooling reaction tower, which is cooled by the function of the air cooling jacket 6.
During this process, conductive carbon black particles with a significantly developed chain structure are deposited on the cooling wall surface.

The conditions for precipitation are that the temperature of the high temperature carbon black suspended gas stream at the time of introduction is maintained at 450°C or higher, the temperature difference between the gas stream and the cooling wall is set to at least 100°C, and the gas flowing upward through the cooling reaction tower is It is desirable to control the flow velocity to 35 m/sec or less.

The most suitable case is to set the gas flow temperature in the range of 500 to 800℃, the cooling wall temperature in the range of 150 to 250℃, and the gas flow rate in the range of 20 to 10 to 7 threads/second. Conductive carbon black can be efficiently deposited.

Although the principle and mechanism by which conductive carbon black is deposited on cooling walls has not yet been fully elucidated,
The fine carbon black particles present in the carbon black suspended gas stream are physically captured by the wall surface due to the temperature difference between the gas stream and the vessel wall, and in this low temperature range, carbon monoxide and hydrogen in the gas stream are The reactions of CO+H, →H, and O+C occur to chemically liberate carbon, and the carbon black particles deposited on the wall undergo high-temperature thermal history, causing desorption of oxygen or active hydrogen, oxidation by moisture and carbon dioxide, etc. It is assumed that this phenomenon is based on a phenomenon in which various factors, such as those that act over time, act in a complex manner.

The surplus carbon black suspended gas flow rising from the cooling reaction tower 5 reaches a collection system such as a bag filter chamber via a conduit 10, and is produced and recovered as a normal type of furnace carbon black by a conventional method.

After operating for a predetermined time, the conductive carbon black deposited on the cooling wall falls into the hopper part 8 by operating the scraper device 7, and then is recovered by the screw conveyor 14 by opening the rotary feeder 13. In a structure in which a plurality of cooling reaction towers 5 are installed, the flow switching valve 11
．． The recovery operation similar to the above was performed for the cooling reaction tower which was closed by intermittently switching the opening and closing of No. 12. Continuous operation is possible by performing this switching and recovery operation alternately.

The conductive carbon black co-produced in this way is
It has a large specific surface area relative to its apparent particle size and a highly developed particle chain structure, and exhibits high specific electrical conductivity comparable to acetylene black under constant compression.

Therefore, it is extremely useful as a conductive filler for rubber, plastic, and other various materials.

According to the present invention, high-performance conductive carbon black can be co-produced at low cost by adding simple steps and equipment to the ordinary furnace carbon black manufacturing process, which is extremely useful industrially.

Example 1: A furnace with a diameter of 650 mm and a length of 1, equipped with an axial combustion burner, a nozzle 2 for material injection, and a tangential air introduction duct 3 in the furnace head, and a quenching spray nozzle 4 in the downstream region.
0. At the rear of the OOO+1III cylindrical generating furnace 1, there is a bottom hopper-shaped cooling reaction with an inner diameter of 394 cm, an effective length of 5000 m+, and an air-cooled side heat transfer area of 23.19 tyt', with a scraper device 7 housed inside and an air cooling jacket 6 attached to the outer surface. A column 5 was installed, and a conduit 9 connected the downstream end of the generating furnace 1 and the lower part of the cooling reaction column. The lower end of the cooling reaction tower 5 is connected to the screw conveyor 1 via a rotary feeder 13.
4, and a conduit 10 connected to the bag filter chamber was connected to the upper part thereof.

Using the apparatus having the above structure, operation was carried out under conditions for producing N-787 (GPF) class furnace carbon black.

The compositions of the applied fuel oil and feedstock oil (aromatic hydrocarbons) are shown in Tables ■ and Table ■, respectively, and the set manufacturing conditions are shown in Table 1.
It was shown to.

Table 1 Composition Table of Fuel Oil 1I Composition Table of Feedstock Oil Production Conditions (Note) *After continuing the carbon black suspended gas flow operation for 5 hours, the conductive carbon black deposited on the wall of the cooling reaction tower 5 was removed using a scraper device. 7 was operated to scrape off the waste, the rotary feeder 13 was opened, and the waste was collected by the screw conveyor 14. On the other hand, the excess carbon black suspended gas flow rising through the cooling reaction tower 5 was led to a bag filter chamber and collected as carbon black particles by a conventional method.

Various properties of the electrically conductive carbon black and N-787 (GPi) class furnace carbon black co-produced in this way were measured, and the results are compared and shown in Table 3.

For comparison, the characteristics of commercially available acetylene black are also listed.

Table ■ (Note) *'Denka Black' [Denki Kagaku Kogyo ■] From the results in Table ■, the conductive carbon black co-produced by the present invention has significantly higher electrical conductivity than the furnace carbon blank obtained at the same time. , A. It has been found that it exhibits an electrical resistance value comparable to that of setylene brazol.

Example 2 Using the same equipment, fuel oil, and raw material oil as in Example 1,
Feedstock oil loss 7'98%/hr, fuel oil amount 78'4
゜Total air i 1873 Nft? /br, amount of gas generated 3
494N, //hr (Wet) conditions (product to be manufactured a)
, N-33° (HAF)) while changing factors such as the temperature and flow rate of the carbon black suspended gas stream and the temperature of the cooling reaction tower wall surface.

The characteristics of the produced furnace carbon black are: iodine adsorption MC86q/f, oil absorption (J-Ko S-B method) 123
cc/1oof, electrical resistance (50Kg/- when compressed) 0
．． 560-α, but the characteristics of the co-produced conductive car pump hook were different due to changes in the above condition factors. The results are shown in Table V.

Table ■ (Note) *The results of the carbon black suspended gas flow table ■ show high electrical conductivity on both sides, but in an example where the gas flow temperature is below 450℃ (Run
In cases where the temperature difference between the gas flow and the cooling reaction tower wall was less than 100°C (Run 1%2), the degree of precipitation of conductive carbon black decreased, and the gas flow rate was 35 m
In these three cases, including the case where the resistance exceeded 1/sec (Run Nn3), a tendency for the electrical resistance to increase slightly was observed.

Figures 2 and 3 show the furnace carbon black and conductive carbon black (uu
This is an electron micrograph (40,000x magnification) of nNn4). It is observed that the conductive carbon black of FIG. 5 exhibits significantly more developed particle agglomeration properties than the simultaneously produced furnace carbon black.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view showing an embodiment of a manufacturing apparatus according to the present invention. FIGS. 2 and 3 are electron micrographs (photographs substituted for drawings) showing the particle structures of furnace carbon black and conductive carbon black obtained by the present invention, respectively. Explanation of symbols in Fig. 1: 1...Generation furnace, 5...Cooling reaction tower, 6...Air cooling jacket, 7...Scraper device, 8.One part of hopper, 11.12...Distribution switching valve. 13...Rotary feeder, ←...Screw conveyor. Patent applicant Masaya Takahata, patent attorney representing Tokai Carbon Co., Ltd.

Claims (1)

[Claims] 1. A high-temperature carbon black suspended gas stream generated by the furnace method is brought into contact with a cooling wall to deposit conductive carbon black on the wall surface, and the surplus carbon black suspended gas stream is extracted by a conventional method. A method for producing furnace carbon black that simultaneously produces conductive carbon black, which consists of a process of collecting ordinary types of carbon black. Co-production of conductive carbon black according to claim 1, in which a high-temperature carbon black suspension gas flow of 2450° C. or higher is brought into contact with a cooling wall having a temperature difference of at least 10] C at a flow rate of 35 m/sec or less A method for producing furnace carbon black. 1 A cooling mechanism in which a downstream end of the generating furnace 1, an air-cooling jacket 6, a scraper device 7, and a pot section 8 are arranged, and a high-temperature carbon black suspended gas flow flows over the inside while contacting the cooling wall. Furnace carbon black manufacturing apparatus that co-produces conductive carbon black, which has a structure in which a reaction tower 5 is connected to the reaction tower 5 via a conduit 9, and a conduit 10 connected to a collection system is connected to the upper part of the cooling reaction tower 5. . 4. The apparatus for producing electrically conductive carbon black according to claim 3, wherein a plurality of hair cooling reaction towers 5 are installed, and each connecting conduit is provided with a flow switching valve 11, 12 for a flow of carbon black suspended gas.