US2680061A - Carbon black - Google Patents

Description

June'fl j.1.954 c.' w.. SwElTz'rilv` CARBON BLACK Filed Feb. 7, 1951 ..\..,.K a a. ....,.......L....

RNEYs Patented June l, 1954 UNITED STATES PTENT OFFICE CARBON BLACK Carl W. Sweitzer, Garden City, N. Y., assignor to Columbian Carbon Company, New York, N. Y., a corporation of Delaware Application February 7, 1951, Serial No. 209,783

3 Claims. (Cl. I23-259.5)

Y and uniformly mixing it with a hot gaseous medium at a temperature in excess of that at which the hydrocarbon is decomposed to carbon black, as described, for instance, in the Wiegand and Braendle Patent No. 2,378,055. The invention also provides improved apparatus especially adapted to the carrying out of the process of the present invention.

In the usual operation of this type of process, the hydrocarbons to be decomposed are separately injected into a turbulent stream of hot blast llame gases flowing at high linear velocity through an elongated, heat insulated, unobstructed chamber, and are decomposed by heat absorbed from the hot gases to form the carbon black in suspension. The resultant gaseous suspension is withdrawn from the downstream end of the furnace chamber and is cooled and the carbon black separated therefrom.

It is particularly desirable in operations of this type that the mixing of the gaseous hydrocarbon to be decomposed, herein referred to as make, with the hot blast dame gases be very rapid and eX- ceedingly uniform. To promote such mixing, it has heretofore been proposed to inject the make through the side walls of the furnace chamber ment of the trajectory of the entering streams of make. It has been found desirable in practicing that procedure to use a relatively narrow furnace chamber and to position the make injection tubes along opposite sides of the chamber so that each tube is directly opposite a similar tube leading into the chamber from the opposite wall, and so to regulate the trajectories of the respective streams that opposite streams substantially meet without overlapping.

The regulation of the trajectory of the gaseous make streams is usually accomplished by a careful control of the mass velocity of the entering make gas streams with respect to the mass velocity of the blast flame gases. This has further imposed certain limitations on the diameter and relative velocities of the entering make gas streams and the relative volumes of the gaseous hydrocarbon make and blast iiame gases.

2 My present invention provides improvements in processes of this general type in that it avoids limitations with respect to `furnace width and with respect to relative volumes and mass veloci- .ties of the make gas and the blast iiame gases. Further advantages of my present invention will hereinafter appear from the following description thereof.

In carrying out my improved process, one may, with advantage, use apparatus of the general type previously proposed with certain improvements herein described. The furnace chamber should be elongated and advantageously is of rectangular cross-section, lined with nrebrick, or other furnace refractory adapted to withstand high temperature, and should be well insulated against heat loss. This chamber should be unobstructed and is, with advantage, of substantially uniform cross-section throughout its length. The hot turbulent gas stream is, with advantage, produced by a blast burner of the general type described in the Ekholm Patent No. 2,529,373, positioned in the upstream end of the chamber. Other burners adapted to deliver to one end of the chamber a hot turbulent stream of gases of substantially uniform composition and velocity throughout the transverse area of the chamber may be employed.

However, instead of injecting the make gas into the chamber through ports in the side walls thereof, as previously proposed. I introduce the make into the furnace chamber as a plurality of relatively small streams uniformly spaced over the entire transverse area of the chamber and positioned in a zone of the chamber near the burner end thereof but downstream from the zone of combustion of the blast flame, and directed downstream substantially parallel to the longitudinal axis of the chamber. This is, with advantage, effected by passing manifold tubes directly across the furnace chamber in the path of the hot combustion gases, said tubes being provided with small perforations, openings or jets on their downstream side.

It is important that the uniformity of the stream of hot combustion gases from the blast burners, in composition and velocity throughout "the transverse area of the chamber, particularly at the point of introduction of the hydrocarbon make,`be disturbed as little as possible. To accomplish this, it is advantageous that the transverse section of the manifold tubes be streamlined, i. e., more or less tear-shaped so that uniformity of now of the hot gases, somewhat dis-- turbed by the presence of the manifold tubes,

will be quickly reestablished at the downstream side of those tubes.

A further advantage of my improved process is that the hydrocarbon make may thereby be preheated to its incipient decomposition temperature in passing through the manifold tubes in heat exchange relation with the hot combustion gases, prior to being mixed with those gases.

The extent of this preheating may be controlled by the rate of flow of the hydrocarbon make through the manifold tubes which, in turn, may be regulated by coordinating the transverse area of the tubes with the intended rate of feed of the hydrocarbon make.

The extent of preheating may thus be regulated to avoid such extended decomposition Yas would result in the plugging of the tubes, or the tube outlets by carbon deposits.

It will be appreciated that the furnace chamber through which these manifold tubes extend `will usually be at a temperature of 2300 ,F., or

higher, and therefpre the tubes should be fabricated of a furnace refractory or alloy capable of withstanding such temperatures, for instance, silicon carbide.

The invention will be further described and illustrated with reference to the accompanying drawings which represent conventionally and somewhat diagrammatically one form of apparatus embodying my invention and particularly adapted to use in the carrying out of the process thereof, and of which Figure l is a longitudinal, somewhat fragmentary sectional View in elevation of the furnace chamber, together with auxiliary equipment;

Figure 2 is a longitudinal sectional plan view of the apparatus of Figure l; and

Figure 3 is a transverse sectional view along the line 3--3- of Figure l.

In the drawings, the furnace chamber I has an inner lining of furnace refractory 2 which, in turn, is covered cy layers 3 and 4 of insulating material, all encased in a sheet metal shell 5. Positioned in the forward end of chamber I is a blast burner head 5, the burner block 'I of the burner head being coextensive with the transverse area of the chamber and of such dimencion as to slide into the forward end of the chamber I, into which it is sealed by conventional means.

In operation, air for combustion is supplied to the blast burner by forcing it under pressure, by any suitable means, through the air inlet S into the wind-box 9 of the blast burner 6, provided with distributing varies It and dampers II for effecting uniform distribution of the air among the respective burner ports I2 uniformly spaced over the entire face of the burner block, The hydrocarbon fuel is supplied to the burner through fuel lines I3 to fuel manifolds I4 and, from thence, is ietted into the respective burner ports through the spuds It. In the burner shown. the manifolds are adjustably supported within the wind-box by a track and roller mechanism It, whereby the spuds may be moved forward or backward with respect to the burner ports.

Hydrocarbon to be decomposed, natural gas, for instance, is supplied to the system through the line I7 branch lines I8 to supply manifolds I9 positioned on either side of the furnace chamber, as more clearly shown in Figure 3 of the drawings. Connected between the supply manifolds I9 and extending horizontally through the furnace chamber are the make gas injection man- -lifolds 2U. Each of the manifolds 20 is connected at each end with the supply manifold I9 through valved connection 2l in which there is interposed a union 22 to facilitate removal and replacement of the make gas injection manifolds where required. Further to facilitate inspection and cleaning each end of the make gas injection manifolds is provided with removable caps 23. It is desirable that these caps do not extend beyond the outer perimeter of the make gas injection manifolds so as to interfere with the sliding of the manifolds through the openings in the furnace wall through which they extend.

These make gas injection manifolds are, with advantage, designed so as to have a streamlined transverse section, as Shown more partioularly in Figure l of the drawings, and are provided at their tapered, downstream side with relatively small openings 24, the spacing of the openings and of the make gas injection manifolds being such that the openings 24 are uniformly spaced over the entire transverse area of the chamber.

In operation, the combustible mixture 4is blasted into the upstream end of the furnace chamber through the ports I2 and burned to form a hot turbulent combustion mixture of blast flame gases. Due to the uniform spacing of the burner ports and the character of the burner, there is produced a hot, highly turbulent stream of combustion gases of substantial uniform velocity, turbulence and composition throughout the transverse area of the combustion zone 25 of the chamber I. By the time the hot blast flame gases have proceeded downstream as far as the make gas injection openings 2iI, combustion of the blast mixture has been substantially completed and, at this point, the hydrocarbon make is introduced into the hot combustion gases substantially uniformly over the entire transverse area of the chamber, thus effecting a rapid, uniform mixing of the hydrocarbon make with said hot gases.

By reason of this uniform mixing of the hydrocarbon make with the hot combustion gases, the heating and dispersion of the hydrocarbon make are uniformly rapid throughout without possibility of channelling of either unmixed combustion gases or non-uniformly mixed hydrocarbon make through the furnace chamber.

The resultant uniform mixture of hot combustion gases and hydrocarbon make proceeds through the furnace chamber in a highly turbulent condition and the hydrocarbon is rapidly decomposed to produce carbon black in suspension in the resultant gas mixture. This suspension passes from the downstream end of the chamber through cooling conduit 25, and from thence, to apparatus, well understood by the art, for separating and collecting the furnace carbon. The cooling conduit may be lined with a suitable furnace refractory 2l, encased in a metal casing 28 and may be provided with water sprays 28 to facilitate cooling of the suspension.

As previously noted, the reaction chamber I `is of suihcient length to provide the necessary time factor for effecting decomposition of the hydrocarbon make. Usually this chamber will be from 5 to l0 feet in length depending upon the intended velocity and rate of throughput and other operating conditions dictated primarily by 'the desired characteristics of the resultant furnace black. Further, as previously noted, the furnace chamber is not restricted as to width, by

reason of my improved method and means for effecting the uniform introduction of the hydrocarbon make. Other conditions including struc- J tural strength permitting, the width of the furnace chamber may be as great as several feet.

In operations of the type described, the hydrocarbon make may, with advantage, be natural gas, or natural gas enriched by the mixing of a higher molecular weight hydrocarbon therewith. Where enriched natural gas is used, the higher molecular weight hydrocarbon in a gaseous or vapor state may be passed to the system through valved connection 30 and mixed with the natural gas passing to the system through line 11. Also where desired, steam may be admixed with the natural gas, or enriched natural gas used as the hydrocarbon make and, when used, may,I with advantage, be supplied to the line I1 through the valved connection 3|.

I claim:

1. Apparatus for producing furnace black which comprises an elongated, heat insulated reaction chamber of rectangular cross-section and delineated by side walls of furnace refactory, a burner positioned in one end of the chamber, said burner being constructed and arranged to generate in said chamber a hot turbulent stream of combustion gases at a temperature in excess of that at which hydrocarbons are decomposed to furnace black and of substantially uniform composition, temperature and velocity throughout the transverse area of the chamber, a multiplicity of parallel make gas injection manifolds extending through said chamber, at a zone thereof downstream from the burner, substantially perpendicular to the side walls thereof and extending through opposite side Walls to without the furnace chamber and uniformly spaced over the height of the chamber, said manifolds being perforated on their downstream side, the perforations being uniformly spaced over the width of the chamber for the jetting of streams of gaseous hydrocarbon into the chamber in a direction substantially parallel to the longitudinal axis of the chamber and connections adapted to supply gaseous hydrocarbons to the outer ends of each of the respective make gas injection manifolds.

2. Apparatus for producing furnace black which comprises an elongated heat-insulated, reaction chamber of rectangular cross-section and delineated by side walls of furnace refractory, a burner positioned in one end of the chamber provided with a multiplicity of burner ports uniformly spaced over the entire transverse area of the chamber, said burner being constructed and arranged to generate in said end of the chamber a hot turbulent stream of combustion gases at a temperature in excess of that at which hydrocarbons are decomposed to furnace black and of substantially uniform composition, temperature and Velocity throughout the trans- Verse area of the chamber, a multiplicity of parallel make gas injection manifolds extending through said chamber, at a zone thereof downstream from the burner, substantially perpendicular to the side walls thereof and extending through opposite side walls to without the furnace chamber and uniformly spaced over the height of the chamber, said manifolds being perforated on their downstream side, the perforations being uniformly spaced over the width of the chamber for the jetting of stream of gaseous hydrocarbon into the chamber in a direction substantially parallel to the longitudinal axis of the chamber and connections adapted to supply gaseous hydrocarbons to the outer ends of each of the make gas injection manifolds.

3. The apparatus of claim 2 in which the respective manifolds are separately removable from the furnace chamber.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 21,521 Shapleigh July 30, 1940 1,758,152 Goodwin May 13, 1930 2,462,026 Loving Feb. 15, 1949 2,499,438 Wiegand et al. Mar. 7, 1950 2,597,991 Heller May 27, 1952

Claims (1)

1. APPARATUS FOR PRODUCING FURNACE BLACKWHICH COMPRISES AN ELONGATED, HEAT INSULATED REACTION CHAMBER OF RECTANGULAR CROSS-SECTION AND DELINEATED BY SIDE WALLS OF FURNACE REFACTORY, A BURNER POSITIONED IN ONE END OF THE CHAMBER, SAID BURNER BEING CONSTRUCTED AND ARRANGED TO GENERATE IN SAID CHAMBER A HOT TURBULENT STREAM OF COMBUSTION GASES AT A TEMPERATURE IN EXCESS OF THAT AT WHICH HYDROCARBONS ARE DECOMPOSED TO FURNACE BLACK AND OF SUBSTANTIALLY UNIFORM COMPOSITION, TEMPERATURE AND VELOCITY THROUGHOUT THE TRANSVERSE AREA OF THE CHAMBER, A MULTIPLICITY OF PARALLEL MAKE GAS INJECTION MANIFOLDS EXTENDING THROUGH SAID CHAMBER, AT A ZONE THEREOF DOWNSTREAM FROM THE BURNER, SUBSTANTIALLY PERPENDICULAR TO THE SIDE WALLS THEREOF AND EXTENDING THROUGH OPPOSITE SIDE WALLS TO WITHOUT THE FURNACE CHAMBER AND UNIFORMLY SPACED OVER THE HEIGHT OF THE CHAMBER, SAID MANIFOLDS BEING PERFORATED ON THEIR DOWNSTREAM SIDE, THE PERFORATIONS BEING UNIFORMLY SPACED OVER THE WIDTH OF THE CHAMBER FOR THE JETTING OF STREAMS OF GASEOUS HYDROCARBON INTO THE CHAMBER IN A DIRECTION SUBSTANTIALLY PARALLEL TO THE LONGITUDINAL AXIS OF THE CHAMBER AND CONNECTIONS ADAPTED TO SUPPLY GASEOUS HYDROCARBONS TO THE OUTER ENDS OF EACH OF THE RESPECTIVE MAKE GAS INJECTION MANIFOLDS.

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