IL43564A - Method and apparatus for the production of carbon black from liquid or gaseous hydrocarbons - Google Patents

Description

D'aa'anoo one mn ns'» j nm no»» Method and apparatus for the production of carbon black from liquid or gaseous hydrocarbons The present invention relates to a method and to apparatus for production of carbon black from liquid and/or •gaseous hydrocarbon raw materials in the presence of an oxygen- containing gas,, especially air, by thermal decomposition during partial combustion of the hydrocarbons in a combustion chamber.

Methods for production of carbon black from liquid and gaseous hydrocarbons are known. In the production of carbon black from normally liquid hydrocarbons, all the known methods and the related apparatus involve the incomplete combustion of hydrocarbon-containing material with air in. a thermally insulated or plain vessel , where a portion of the is. hydrocarbons aj?e burned and the remainder cracked by the heat of combustion thus developed. In all known methods the heating or fuel gas, for example natural gas, propane, a petroleum distillate vapor, or the like, must be added with a sufficient amount of a gas containing free oxygen, normally air, and burned in a reactor, and the normally liquid starting product for the production of carbon black is sprayed into the flames or into their combustion products. Usually more than the amount Of air necessary for the complete combustion of the heating gas is supplied to the carbon black oven, as a result of which, however, only a very small portion of the liquid hydrocarbon is burned along with the heating gas. Moreover, in the production of carbon black by these methods, a part of the product appears in the form of carbon grit which must then be separately ground.

All the known production methods operate at very high temperatures, in the range above 1300° C. The reaction in the reaction chamber, the combustion system and the operating conditions affecting the carbon black quality involve factors difficult to control. In addition, the carbon black produced must still be quenched with a continuous water jet.

T e apparatus used in the known carbon black production methods consist of completely metallic or more or less horizontal reactors in which the pyrolysis is carried out in metallic reaction tubes provided with a heat conducting fire-proof coating or else in uncoated tubes, or else they consist of a first oven cylinder having a diameter greater than its length, to which a second cylinder is connected in the axial direction.

In the known methods of producing carbon black from gaseous hydrocarbons the reaction of the gas mixture takes place in relatively small containers with a capacity of at most 10 liters, in which the gas mixture is cyclically admitted and through an intake valve /from which the reaction products are cyclically discharged after the reaction -through an exhaust valve. A very low yield per chamber filling is obtained for each reaction, as a result of which the economics of this method are unsatisfactory. Furthermore, in the known methods it is necessary to operate with supplements of liquid hydro Another method, known as the channel Proces3 is known, in which natural gas is burned in thousands of small flames in a "hothouse". The oxygen requirement for the maintenance of combustion is met by supplying air. The little flames are slowly moved back and forth in steel channels, while the r carbon black is scraped off fixed steel plates and falls into a conveyor bucket by which it is taken to a carbon grit is separator. The carbon black/blown through the separator, where the heavy particles (grit) are separated. There is in this procedure the disadvantage that the carbon black yield is very low, i.e. not higher than 5% of the input carbon content and the products made by this process, particularly pigment grade carbon black, are accordingly very costly.

It is an object of the present invention to provide a method and an apparatus for the production of carbon black which are not subject to the disadvantages of the known apparatus but will make possible the production of carbon black at high yield in a wide variety of carbon black types with the use of the same equipment.

Subject matter of the present invention; Briefly, the hydrocarbons and the oxygen-containing gas are preconditioned before their admission to the reaction zone of the oven and are thereupon introduced in the reaction zone in a homogeneous gaseous state. The resulting reaction products are cooled and then separated. The apparatus for carrying out the process is characterized by the fact that the combustion chamber, which may have a vertical or a horizontal axis, has a header at the input end or side in which a plurality of ante¬ chambers are provided that are distributed over the combustion cross section and, furthermore, that on. the output side of the chamb r combustion there are provided a cooler for the reaction products ,a pre-heater for the combustion supporting gas and thereafter a separator apparatus for separating the carbon black. is The invention/further described by way of example with reference to the annexed drawings, in which: Fig. 1 is an operation diagram of a complete installation for the production of carbon black; Fig. 2 is a schematic representation of an installatio according to Fig. 1, showing its principal components; Fig. 3 is a cross section through the header of the combustion chamber of the system of Fig. 1; and Fig. 4 is a cross section of a mixing apparatus for the mixing of gaseous hydrocarbons with an oxygen-containing gas.

In Fig. 1, piping for liquid hydrocarbon transfer, which may be referred to for short as "oil piping", is shown in solid lines, while dashed lines indicate air piping and ducts and dotted lines indicate control lines 17. Temperature sensors are designated by the reference numeral 23, temperature indicators by 35, and shut-off valves by 12.

In the system of Fig. 1, the hydrocarbon such as heavy petroleum oil, for example, and an oxygen-containing gas such as air are used for the production of carbon black. There is a combustion chamber 1 provided with a header 81 covering the intake side and these as well as adjacent associated parts are warmed by a pre-heater burner 4 provided in the combustion chamber wall structure or in the header 81. The pre-heat burner 4 is supplied with gas, for example propane, from a gas tank 10 over a supply pipe 3 and is supplied with air to support combustion over piping 7 from an air blower 5 driven by an electric motor 6. The spent gases of the pre-heat burner flow into the combustion chamber 1 and from the combustion chamber over a transition section 2 with expansion flap valves 84 into a cooler 8 and into an air pre-heater 9. After jfefee leaving the latter^ the combustion products, which may be referred to as spent gas or smoke gas, proceed through a gathering funnel or cone 86 and a connection duct 85 into a carbon black separator 108, 109 and from there into a chimney 75. Depending upon the design and construction of the chimney 75 it may be necessary to provide a suction blower 74 driven by an electric motor 73 ahead of the chimney 75, as shown in Fig. 1.

Equipment for the conditioning of the heavy oil^ shown at the left of Fig. l.includes a storage tank 11 which is. connected over a practically pressureless supply pipe 20 with a' pre-heating input tank '18. Interposed in the supply line 2 are shut-off valves 12, filters 13, two rotary pumps 14 (one stand-by) each driven by a motor 15, and a measuring device 16 provided with a bypass. At the input tank 18 a level sensitive switch 19 is provided which is connected with the motor 15 of the rotary pump 14 over a control line 17.

A heating element equipped with a thermostat 21 is provided in the input tank 18, as well as a temperature regulator 22 (for regulating the temperature to about 40° C) and a temperature sensor 23 connected to a temperature indicating device 35.

•A conduit 25 leads from the input tank 18 over regulating valves 26, of which one is in stand-by service to a pair of pressure pumps 27, of which again one is for stand-by, each driven by an electric motor 28, to provide a pressure of about 30 atm. The pressure line 29 leads to a pass-through heater 31 provided with a heating element 30 and controlled by a thermostat 32 and a temperature regulator 33. The heavy oil, heated to about 130° C; goes from the heater 31 to a pressure regulator 34 from which there is a return line '24 to the input tank 18 and an output pressure line 36 to the distribution pipes 42 for a number of injection nozzles 43 of which two are shown in Fig. 1. The quantity of oil flowing to the spray nozzles 43 is regulated by a quantity regulator that comprises a return line 37, an. input quantity regulator 38 and a control or motor 39. An oil injection pressure gauge 40 and a temperature sensor 23 are provided in the pressure line 36, the measurements of which are displayed in an indicator device 35. In each of the individual lines feeding the spray nozzles 43 a flow monitor 41 and a shut-off .valve are provided.

The rate of feed of the heavy oil to the spray nozzle 43, which may for example be 800 kg/h, is measured by a rotary ·„ piston . counter 45, the output signal of which is converted to a pneumatic signal by a transmitter 44. This pneumatic signal is supplied to the indicator device 46 to display the rate of feed to the spray nozzles 43 and is also supplied to the ratio relay 47 for adjustment of the air-oil to ratio, to an air ratio regulator 48 and/a pneumatic range regulator 49.

The combustion air is delivered by a blower 53 driven by an electric motor 54. A damper valve with a pneumatic 49 drive 50 regulated by the range regulator/ is provided for control of the suction intake 52 of the blower 53. In the pressure duct 55 following the blower 53 a measuring diaphragm 58 is provided where a pressure difference is measured from which a pneumatic computing relay 57 computes the air feed 2 rate (about 3000 - 7000 Nm ) . An air feed rate indicator 56 displays the signal of the computing relay 57, which is also supplied to the ratio regulator 48. The pressure line 55 discharges into the intake manifold 59 of an air pre-heater 9 o ^ which heats the combustion air to abo t 300 C. The combustion air leaving the hot. air exit 62 of the pre-heater 9 proceeds over a conduit 67 to an air distribution chamber 63 from which it is delivered to the ante-chambers 82 through openings 68. A pressure gauge 64 and a temperature sensor 23 are. provided in the conduit 67. A temperature sensor signal is provided over a control line 17 to a temperature indicator 35 which also displays temperature, sensed by another temperature sensor in the final separator 109,. A measuring diaphragm 65 to measure the rate of air supply can be built into the pressure line 67.

The combustion chamber 1 is equipped with a further transmitter device 69 to provide a signal to a pneumatic under¬ pressure-regulator 70 and an associate range control 71. More details regarding these instruments are given in Table IX below.

The regulators 70 and 71 operate with reference to a desired value of pressure that is to be maintained, which can be manually set, for example an underpressure of a few millimeters of water, and supply a signal indicating the detected deviation from this desired value, which then operates the pneumatic drive setting the position of the regulating damper 77 in the chimney 75 in order to correct the pressure deviation measured.

The chimney 75 discharges the residual gases coming out of the carbon black separator installation designated by the reference numerals 1 08 through 1 23 , so that the regulation of the damper 77 just described maintains the regulated under¬ pressure in the combustion chamber 1 and in the portions of the installation in communication with it.

Two temperature sensors 23 and two temperature indicators 3 5 are provided on the combustion chamber that is constructed with a removable cover in the form of the header 8 1 in which the ante-chambers 82 are built in. The cylindrical combustion chamber wall 83 has a tapered transition on its exit side which is provided by the transition section 2 , to which is connected the air cooler 8 that serves to cool the reaction products that enter it at a temperature that has a. maximum value of 1 200 ° C. The cooled reaction products go immediately from the air cooler to the cooling of the pre-heater 9 that operates as a heat exchanger, cooling the reaction products and warming the air supplied to support combustion.

The reaction products are at about 300 ° C when they reach the duct 85 leading to the cyclone-type preliminary carbon black separator 1 08 in which a certain quantity of carbon black is separated and which can consist of a number of cyclone units.

The remaining reaction products are led by a connection duct 1 1 2 , at a temperature of about 250 ° C measured at the duct input by a temperature sensor 23 , to a final carbon black separator 1 09 of the filter type where all of the remaining is carbon black/separated from the other reaction products.

The residual gas proceeds through .a suction intake 107 to the suction blower 74 and thence into the chimney 75. The carbon black separated in the separators 108 and 109 drops through carbon black exit openings 111 into a horizontal carbon black conveyor 113, from which it is delivered to ah inclined . lifting conveyor 114 in which there is built in a carbon black compression device 110, for example a hinged flap provided with a weight to produce a compression effect, until the carbon black reaches the upper end of a collecting hopper 118 provided with a gathering cone 119. Above the collecting hopper 118 is a vane-type charging valve 117 for the carbon black controlled by an electric motor 116 into which the carbon black is delivered through a guiding vessel 115. Below the collecting cone 119 a filling device 121 for the. carbon black is provided which is equipped with a carbon black scale 120, a scale platform 122 and a packing vessel 123.

In order to make possible the pre-heating of the portions 111 , 113 and 114 of the carbon black conveyor, a connecting duct 76 equipped with a shut-off damper (not shown) is arranged between the guiding vessel 115 and the suction intake 107 of the suction blower 74. When the damper of the duct 76 is opened, the spent gases are caused to circulate through the lower portions as well. as the upper portions of the separating apparatus, and this mode of operation is used during the preliminary heating of the combustion chamber to warm up the conveyor units. - Fig. 2 shows an arrangement of the installation more diagrammatically shown in Fig. 1. In this Figure, as is the case also in Fig. 3 , the. same reference numerals are accordingly used for the same component elements.

The component equipments of the installation are supported on a foundation or other prepared site 1 05 by struts 1 00 , 1 04 and 106 , while the blowers 53 and 1 01 , the input tank 18 and the pre-conditioning equipment 1 1 - 58 for the heavy oil raw material are conveniently located in a basement below the other equipment. The central operation and control equipment is not shown in Fig. 2 and it may conveniently be provided in a separate or remote location.

The blower 1 01 serves for the cooling of the reactio product gases, that may simply be referred to as the smoke gases. The blower 1 0 1 is directly connected to the input manifold 1 02 of the smoke cooler 8 . The air thereby warmed is led over a duct 1 03 to the chimney 75 . The cold air output of the blower 1 0 1 is regulated by a throttle valve 51 as a function of the temperature measured at the output funnel cone 86 by a temperature sensor 23 in such a way that the smoke enters the combustion air pre-heater at a sufficiently high temperature and leaves the latter at a predetermined temperature.

Fig. 3 shows the header 81 of the combustion chamber 1 with the air distribution chamber 63 mounted thereon.

Centrally located in this assembly is the pre-heat burner 4 with which the fuel and air lines 3 and 7 are connected. The spray nozzles 43, associated with the ante-chambers 82 ; are uniformly . distributed over the entire cross section of the combustion chamber 1. The injection nozzles 43 are affixed to retractable tubes 90, at the other end of each of which is provided a positioning coupling 91 with which a piece of flexible tubing (not shown) connects to provide the necessary connection to the supply distribution pipe 42.

Flange-like holders 92 are provided on the cover of the air distributing chamber 63 for holding the tubes 90 so as to make possible retraction., of the tubes 90 with their spray nozzles 43 as well as to hold them fast in any desired position with the help of set screws 129. The components provided in the tubes 90 shown in Fig. 1 - shut-off valve 12, flow monitor 41 and a pump 88 - are omitted in Fig. 3 for reasons of simplification. A distributing apparatus 137 which may be referred to as. a diffuser is adjustably mounted in the neighborhood of the injection nozzle 43.

Flaring ante-chambers 82 are built into the header 81 with suitable ceramic construction materials indicated at 144. The length of the ante-chambers 82 is sufficient for a complete vaporization of the hydrocarbon material. The header 81 is provided with a header flange 92 by which it is bolted onto the cylindrical portion of the combustion chamber 1 The latter has a cylindrical wall 93 made of heat resistant metal sheet or plate. It is practical to provide the metal envelope 93 of the combustion chamber with a cooling ar>d heating coil 94, of which one winding is shown in Fig. 3.

In addition, it is desirable to coat the exterior of the metal wall 93 with an insulating layer or body 95.

If the installation described with reference to Fig. 1 and Fig. 2 is operated with gaseous hydrocarbons as raw material, the components 11 - 58 are not needed. At the pre-heater intake manifold 59 a mixing equipment as shown ^η Fig. 4 is then connected by means of a flange 180. At the location 166 of' the mixing equipment, there come together two tube conduits, one of which supplies gaseous hydrocarbons provided over a pressure reducing valve 148, an equalization vessel 154 filled with a suitable packing material 155, for example rust-free steel wool, a diaphragm gate valve 159 with an adjustable diaphragm 160 and an electric drive 161 controlled by a switch 162 and, finally, a restricted conduit 164. The other conduit 165 leading to the location 166 supplies combustion air from a blower 150 driven by an electric motor 151, through a pressure-reducing valve 152, an equalization vessel 154 filled with a suitable packing material 155, a diaphragm gate valve 157 with an adjustable diaphragm tube section 165.

At the junction 166 of the tubes 164 and 165 a mixing suction blower 169 provided with a. ventilator 170 , a multi-stage switch 171 and a multi-stage electric motor 172 is arranged to feed the mixture into the homogenizing path 175 equipped with perforated vanes or partitions 176. On the exit side of the homogenizing unit 175 is provided a check vessel 177 for counteracting back-pressure, provided, with a filling 178 of a suitable packing material and an expansion safety valve 179. Control manometers 156 are provided at various locations of the mixing equipment.

In the mixing equipment constructed in accordance with Fig. 4, the diaphragm gate valve 159 for the gaseous hydrocarbon material can operate independently of the diaphragm gate valve for the air supply and each can be adjusted and regulated individually for the desired flow rate. The tubing sections 164 and 165 have greatly differing cross sections as a consequence of the desired mixing ratios, which for example may be one part gaseous hydrocarbon to four to six parts air, according to the desired carbon black quality. At the location 166 the formation of the mixture takes place which becomes fully mixed in the homogenizing path 175 that follows the blower 169. In order to assure a constant mixing ratio it is practical to hold constant the pressure ahead of the two diaphragm gate valves.

Either the gas or the air can be regulated by the adjustment of the regulating diaphragms so that every quality of carbon black can be produced. . The optimum mixing ratio for each quality of carbon black can conveniently be determined by test runs . ' ' The chemical basis for carbon black production using liquid and gaseous hydrocarbons as raw material is the decomposition of paraffinic hydrocarbons at high temperatures into their elementary components carbon and hydrogen. The reaction which already begins at 900° C and increases in yield with increasing temperature, absorbs heat and goes to completion by the separation of carbon according to the following equations: (1) C H — n C + 7Γ H„ (Δ H endothermic) n m 2 2 For example, for CH^: (2) CH4 — C + 2H2 (Δ H = 17.87 kcal) In order to produce a continuous dropping out of carbon black resulting from thermal decomposition of liquid or gaseous hydrocarbons, the heat necessary for the reaction is provided directly to the reaction process by a partial combustion with air of the input hydrocarbons. Along with the decomposition reaction itself, then, a heat-liberating reaction takes place in accordance with the following equation: (3) C- H + air x CC + y CO + ? H_0 (x + y = n) n m £· /. Δ For example, for CH^: (4) 2CH4 + 2.5 02 + 10.N > C02 + CO + 2^0 + 10 N2 (Δ H = 201.2 kcal) At the same time a portion of the reagents combine according to the following equation: (5) CH4 + H20 > CO + 3H2.

By control of the hydrocarbon-air ratio the overall reaction can be caused to run on an optimum basis, preferably between about 1000 and 1200° C,and the quality of the carbon black dropping out of the reaction products can be controlled in a reproducible way. In this manner it is possible to produce carbon black of high value to different specifications with a yield of 10 to 85% using heavy oil or 10 to 35% using natural gas, in terms of percentage of carbon input. An appreciable quantity of a residual gas of good usability as a heating gas is formed as a byproduct.

It is important that both the hydrocarbons and the oxygen-containing gas should be delivered in exactly measured out quantities (rates) and conditioned for supply to the installation here described. The conditioning in this case is performed before and/or after entrance into the ante-chambers 82. In the system described in Figs. 1 and 2 the heavy oil is warmed to about 125° C, measured out and put under pressure at about 25 atm. , after which further conditioning is carried ut, i.e. the atomizing and vaporizing in the ante-chambers 82 Only a practically completely homogenized and gaseous mixture enters into the reaction zone of the combustion chamber 1.

In the case of gaseous hydrocarbons the conditioning is largely accomplished before introduction into the antechambers 82, whereas in the ante-chambers themselves a further warming of the mixture takes place, since the temperature in the ante-chambers 82 is above 600° C.

The mixing of the liquid hydrocarbons with the. combustion air which has been conditioned (i.e. heated) in the air pre-heater 9 takes place in the ante-chambers 82 in the case of an installation according to Fig. 1, but in the when disposition of the installation operating with gaseous hydrocarbons as a starting material, this mixing takes place in the mixing apparatus according to Fig. 4.

The ante-chambers 82 which are important for carrying out the method of the invention are relatively small compared to the combustion chamber 1. It is desirable to distribute the ante-chambers 82 evenly over the cross section of the combustion chamber 1. The header 81 must· accordingly have sufficient strength in the ceramic material 144 for housing the ante-chambers 82. An improvement of operation safety when liquid hydrocarbons are used as raw material is obtained if, as shown in Fig. 1, in each branch of the distributing piping 42, ahead of the flow monitor 41 there is provided a feed control pump 88 driven by one or more motor or motors (not shown) . These will supply a quantity and rate of feed practically independent of the momentary pressure. If a partial blocking occurs in an injection nozzle 43 because of the presence of a foreign body, the pressure in the corresponding feed control pump 88 rises and the foreign body can thereby be expelled.

When feed control pumps 88 are used it is possible to lower the pressure in the pressure line 36.

There are given in the following tables observed data obtained in the manufacture of five types of carbon black produced from heavy oil in accordance with the present invention and also the characteristics of twelve different types of carbon black that may be produced in an installation according to the present invention.

TABLE I Analysis of the heavy petroleum raw material; Specific gravity at 20°C = 1.078 Carbon content in % = 90.25 Hydrogen content in % = 8.11 Sulfur content in % = 1.40 Oxide ashes in % by weight = 0.016 Flash point by Pensky-Martens test at °C = 153.0 Water = None Color: dark-brown to black, viscous = 180.0°c On the basis of the analysis results, the material was a very heavy residual oil.

Still further aromatic heavy oils of various compositions have been used.

TABLE II τ Process Conditions Oil spray injection pressure in atm. above 1 atm. = 26.5 Oil spray injection temperature in °C = 128.0 - Air intake temperature in °C = 195.0 ' ante-chamber temperature in °C = 740.0 - Combustion chamber temperature in °C = 1050.0 TABLE III Test results for carbon in synthetic rubber; Volcanizing time FROSSRUSS" types of black: in Min. Type-150 Type-250 iodine surface in m /g 59.1 98.4 oil adsorption in l/g^ 1.07 1.14 tensile strength in kp/cm'' 50 295 311 elongation in per cent 50 525 575 300 % shear modulus 50 2635 2500 expansion stiffness in % 50 68 73 o snapback at 100 C 56.9 50.7 wear loss in gif 3.65 3.24 TABLE IV Physical and chemical data for rubber and pigment blacks; "FROSSRUSS" types of black 2 , . nxtrogen surface m m /gr 81.8 211.2 358. 9 color intensity in Nigrometer-lndex 89 71 59 oil adsorption in 1.12 1.18 1. 24 pH - value = 7.2 6.1 3. 5 ash content in per cent = 0.04 0.03 0. 02 tar content in per cent = 0.06 0.02 0. 01 moisture content in per cent 0.38 0.23 0. 12 TABLE V "FROSSRUSS" carbon black types and their characteristics; Adsorption in Adsorption in "FROSSRUSS" black type I'2 surface N? surface Rubber blacks: No. 1 Type 50 23.5 m 2/y 27 g 27.5 m /g NO. 2 = Type 100 39.8 m2/g 2 .

No. 3 = Type 150 59.1 m /g No. 4 = Type 200 76.0 m2/g 81.8 m 2//g No. 5 = Type 250 98.4 m2/g 103.9 m2/g 2 , No. 6 = Type 300 130.4 m2/g 134.2 m /g Pigment blacks: No. 7 = Type 350 184.8 m /g 188.1 m2/g No. 8 ■ = Type 400 206.0 m /g 211.2 m 2//g 2.

No. 9 = Type 450 237.3 m /g 241.7 m2/g No. 10 = Type 500 301.5 m2/g No. 11 = · Type 550 351.0 m2/g 358.9 m2/g No. 12 = Type 600 398.6 m2/g Intermediate types between the above grades made under trademark "FROSSRUSS" can likewise be produced with the apparatus and method of the invention.

ANALYSIS RESULTS FOR TWO KINDS OF BLACK PRODUCED FROM GASEOUfr HYDROCARBONS IN ACCORDANCE WITH THE INVENTION TABLE VI - Analysis of the natural qas used: methane (CH4) in = 98.30 ethane (C H ) in % 1.50 2. 6 .nitrogen ( 2) in % 0.20 100.00 TABLE VII - Carbon content and heat value of the natural qas used; 3 In one Nm of natural gas, there are: carbon in grams = 547.80 heat value = H^ - kcal/Nm^ = 9562.00 TABLE VIII - Physical and chemical data: Example 1 Example.2 2 surface in m^/g = 240.00 490.00 Color intensity = 69.50 57.00 Moisture in per cent = 0.90 0.60 pH - value = 3.80 3.50 Ash content in per cent = 0.02 0.03 Acetone extract in per cent = 0.009 0.005 Tar extract in per cent = .0.0015 0.001 From the same natural gas materia.}., still other different " " The following table lists useful information on the characteristics of some of the elements of instrumentation of Fig. 1 described rather briefly above in the interest of making clear the operation of the installatio and process as a whole.

TABLE IX Ref. No in Fig. 1 Kind Characteristics 45 Volume counter 6/ counting drums, summing type Minimum indication 0.1 1 Built-in max. range 1200 1/h Frequency transmitter 44 Measurement converter input signal 4-20mA output 0.2-1 bar 46 Manometer input signal 0.2-1 bar scale 0 to lOOOkg/h 41 Flow monitor max. temp. 150°C switching point adjustabl from 0.7-56 1/min. 47 Ratio relay linear over 10-1 range scale 0.2:1 to 2.0:1 4b Ratio regulator with control value setting for fixed value, manual-automa ic switch, an external control value switch 2 range 7000m /h . (air) 49 Range regulator proportional range: 1-500% integrating range: 0.02-50 rpm - Pneumatic Drive Closed when pressure off; spring Damper range 0.6-1.4 bar; with built-in valve regulator and manometer; provided with control disc giving the damper a nearl linear regulator characteristic Measuring Insertion length 25mm, between Diaphragm flanges Operating pressure 50mm WS for flow of 7000 Nm 3/h air at 20°C Pneumatic Range adjustable from 25 to Differential 150 mm WS, fixed at 0-50 mm WS; Pressure Transmembrane good for over-pressure mitter to 2 kp/crn^ in both directions - Accuracy - 0.5% of the range Feed: 1.4 bar Output signal: 0.2 - 1 bar Pneumatic computing Root extraction type, suitable relay for linearizing the air feed rate signal from transmitter of diaphragm 58 Input and output signals: 0.2 1 bar Manometer Scale 0-7000 Nm 3/h Divisions 25 Nm 3/h Input signal: 0.2 - 1 bar Throttle Valve Open when pressure off; electo- Pneumatic Drive pneumatic drive of nearly linear regulation characteristic; built- in limit switch to turn off flower 101 when the damper is closed Pneumatic Vacuum Differential pressure transmitter Meter signaling amount of vacuum in chamber 1 Range fixed at -10 to +15 Nm WS (water, static) Other data as for differential Pneumatic Clearly visible indication of Indicator desired and actual values of oven under pressure, from -10 to +5 Nm WS; with desired value transmitter and manual-to- automatic switch built into control console Pneumatic PID Input and output signals 0.2 -1 Regulator bar Proportional range: 1 -500% adjustable Integrating range: 0.0 to 100 rpm Differential range: 0.01-50 min. ; with built-in cutoff relay (in control console) Damper with Gate-type throttle value with Pneumatic Drive external roller bearings; open pressure off; with built-in positioning regulator of nearly linear characteristic Further combinations of different natural gases have been used for the production of carbon black, for example: (a) . - methane (CH4) = 97.2 %; ethane (C2H6) = 2.1 % and nitrogen (^) = 0.7 %, by volume, and (b) - methane (CHj = 83.4 %; ethane (C-H^) = 8.6 %: . 4 ■ Z o propane = 3.2 %; butane (C4Hl0) = 0.7 %; pentane (C_H,_) = .01 % b 12 and nitrogen (N^) = 4.0 , by volume.

. Given below are the results of two measurements in which air was used as the oxygen-containing gas . For the production of one kilogram of carbon black there were needed: 3 Type 200: 10.2 Nm of air and 2.4 kg of heavy oil 3 i.e. 4.25 -Nm per kg of heavy oil 3 Type 400: 25.4 Nm of air and 4.3 kg of heavy oil 3 i.e. 5.9 Nm per kg of heavy oil.

For the complete combustion of the heavy oil accordin 3 to the above-mentioned analysis, 10.27 Nm of air per kg of heavy oil would be necessary, so that the amount of air supplied in the above instances is: Type 200 about 41 % Type 400 about 57.5 % of the minimum amount of air needed for the complete combustion of the heavy oil.

It is observable from the residual gas analysis that approximately 9 to 11 % by volume of C02 and approximately 6 to 1 % by volume of CO are the largest components, whereas the U^, CH^ and C^H components (heavy hydrocarbons) are substantially smaller and amount to only a few percent.

The essentials of the process here described stand out clearly from these two experiments. According to the adjustment of the oil-air ratio that is chosen, a particular quality of carbon black can be produced in a reproducible way. The finer the carbon black quality is to be, the greater must be the proportion of the air in the mixture. Thus, for the pigment quality carbon black Type 400 the required air amounts to 1.4 times the air requirements for the rubber-compounding quality of carbon black, Type 200. The portion of the heavy oil that is not converted into carbon black is burned and serves to maintain the reaction temperature in the combustion chamber .

By the conditioning of the heavy oil and of the air before introduction into the combustion chamber and by the regulation of the oven input and output it is possible to obtain continuous operation and constant maintenance of the reaction conditions in the combustion chamber without the necessity of adding a carrier gas, of providing quenching with a water stream or other supplementary means.

It is also possible to interrupt the production of desired time with the same output quality or some other output quality without the time-consuming preparatory labors previously necessary. After the warming-up period previously mentioned, the production of carbon black can immediately there after be resumed. In the production installations of the type here described there is practicall no limitation with reference to the variation of the quality .of the carbon black output.

Claims (9)

1. 43564 The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: Li, 1. A method for the production of carbon black from liquid hydrocarbons in .the presence of an oxygen-containing gas by thermal decomposition of the hydrocarbons through partial combustion in a combustion chamber, comprising the steps of: a) pressurizing and preheating said liquid hydrocarbons; b) preheating said oxygen-containing gas; c) distributing said pressurized and preheated liquid, hydrocarbons to a plurality of vaporization locations in space communicating with a combustion chamber, said locations being substantially evenly distributed over an area adjacent to a reaction zone of said combustion chamber; d) distributing said preheated oxygen-containing gas to a plurality of introduction orifices likewise substantially evenly distributed over said area; e) vaporizing said hydrocarbons and mixing them with said gas at said vaporization locations; f) decomposing said hydrocarbons while partially burning ' ' ' o o them in said reaction zone at a temperature between 950 and 1200 C, and then g) cooling the reaction products by indirect heat exchange with at least one stream of cooling medium and separating the resulting reaction products.

2. Method according to claim 1, in which said oxygen-containing gas is preheated and is distributed to said orifices under pressure, and in which, further, said vaporizing locations are respectively in antechambers open to and adjoining the reaction zone of said combustion chamber and are subject to a final stage of preheating of the reaction mixture from which combustion products are used to contribute heat to the combustion chamber. 43564-2

3. Method according to claim 1, in which the vaporizing step is carried out by atomizing said liquid hydrocarbons under high pressure and in which said oxygen-containing gas is separately introduced to each of the vaporization locations.

4. Method according to claim 3, in which said liquid hydrocarbons coVisist essentially of heavy petroleum oil.

5. Method according to claim 1, in which the quality of the carbon black produced is regulated by control of the relative mix of hydrocarbons and oxygen-containing gas.

6. Method according to claim 1, in which the reaction products are cooled at least in part by giving up heat through a heat exchange partition to the stream of said oxygen-containing gas being supplied to support combustion, said heat transfer being caused to take .place at a location spaced close to the location where the reaction products leave the reaction zone.

7. Method according to claim 1, in which the reaction pro'ducts are cooled by giving up heat through a heat exchange partition at a location adjacent to where the reaction products leave the reaction zone arid in which cooling air is provided to pick up heat so giveti up through said partition and is thereafter mixed with residual gases of said reaction products after separation of recoverable carbon black and exhausted therewith. ' "8 '": "Me'thod ·'according*"to-*c±a±nr"Iy in-which* the temperature of the reaction zone is held between 950° and 1200°C by sensing the temperature in said combustion chamber, supplying additional heat to the combustion chamber when the temperature in the reaction zone approaches 950 °C and providing additional removal of heat from the reaction chamber when the temperature in the reaction zone approaches 1200 °C. 43564 9. Method according to claim 8, in which the supplying of additional heat or the provision of additional removal of heat respectively to and from the combustion chamber is carried out so as to maintain the temperature in the reaction zone at approximatively 1100 °C. \ 10. Method according to claim 1, which also comprises the additional steps of exhausting the residual gas remaining after the step of separating the reaction products to the atmosphere in a manner lozering the pressure in the combustion chamber as well as in the locations in which the steps of cooling and separating are carried out, sensing the pressure in the combustion chamber and controlling the exhausting of said residual gas in accordance with the pressure so sensed. 11. Method according to claim 1, in which the step of exhausting said residual gas is carried out by exhausting at least a part thereof through a path of which a portion is adjacent to at least part of the delivery path of the separated carbon black during any period of operation of the method during which the temperature of said last-mentioned path would otherwise be abnor^ mally low. 12. A method for the production of carbon black from gaseous hydrocarbons in the presence of an oxygen-containing gas by thermal decomposition of the hydrocarbons through partial cora- _i)ustion in a combustion chamber, comprising the steps of: a)' pressurizing said hydrocarbons; b) pressurizing said oxygen-containing gas; c) supplying. said pressurized hydrocarbons and said pres- surrized oxygen-containing gas to a mixing chamber; d) mixing the hydrocarbons and the oxygen-containing gas in said mixing chamber; 43564- e) preheating the mixed hydrocarbons and oxygen-con- taining gas; f) introducing said preheated and mixed gas into a combustion chamber through entrances evenly distributed over an area forming a boundary of said combustion chamber wl^ile further preheating said mixed gas so as to distribute said gas over the entrance cross-section of a -reaction zone of said combustion chamber; g) partially burning said hydrocarbons in said mixed gas in said reaction zone of said combustion chamber at a temperature between 950° and 1200°C; h) cooling the reaction products immediately after they leave said combustion chamber by transfer of heat through a heat exchange—partition -to■·■ - . cooii¾g-^ed um~-&tifeam>■—a-n-el—— i) separating the reaction products, immediately after cooling, into a residual gas and solids consisting essentially of carbon black. 13. Method according to claim 12, in which the step of separating the reaction products is 'followed by exhausting the , residual gas in such a manner as. to controlably reduce the pressure in. said combustion chamber. 14. Method according to claim 12, in which the oxygen-containing gas is air and in which the proportion of hydrocarbon gas and air mixed in the mixing chambers. is in. the range of 4 to 6 parts of air per part of hydrocarbon gas. 15. Method according to claim 12, in which the first preheating of the mixed reaction gas is carried out by picking up heat from the reaction products by transfer of heat through a heat exchange partition, which heat transfer effects at least part of the cooling step. 16. Method according to claim 12, in which the quality of the carbon black produced is regulated by control of the rela "* tive amounts of gaseous hydrocarbons and of oxygen-containing gas mixed in said mixing chamber. \ 17. Method according to claim 12, in which the step of supplying said hydrocarbons and said oxygen-containing gas to said mixing chamber is carried out by passing each through an individual pressure equalizing chamber after reducing the pressure and before controlling the mixing ratio, and then controlling the mixing ratio by separate valving,.and in which the mixing step includes passing the partially mixed gas through a homogenizing path. 1

8. Method according to claim 12, in which the temperature of the reaction zone is held between 950° and 1200°C by sensin the temperature in said combustion chamber, supplying additional heat to the combutipn chamber when the temperature in the reaction zone approaches 950°C and providing additional removal of heat from the reaction chamber when the temperature in the reaction zone approaches 1200°C. 1

9. Method according to claim 18, in which the supplying of additional heat or the provision of additional removal of heat respectively to and from the combustion chamber is carried out so as ...to maintain the temperature in the reaction zone at approximat^- 20. An apparatus.. for ithe production of carbon black by thermal decomposition of hydrocarbons through partial combustion with an oxygen-containing gas following preliminary homogenizing of the reagents, said apparatus comprising : - a combustion chamber; combustion chamber and provided with a plurality of ante-chambers distributed over the cross-section of the combustion chamber; - a smoke cooler for the reaction products adjoining the combustion chamber on the exit side; - a heat exchanger arranged for further coaling of the output of said cooler and for pre-heating a combution-supporting gas for said combustion chamber; and - a separating apparatus for separating carbon black arranged to be supplied with the cooled output of said heat exchanger and comprising a preliminary separator of the flow-pattern-influence type and a final separator of the porous filter type. 21. Apparatus according to claim 20, in which said smoke cooler is closely coupled to said combustion chamber and the cooling passages of said heat exchanger are closely coupled to said smoke cooler. 22. Apparatus according to, claim 20, in which a transition section is interposed between said Combustion chamber and said smoke cooler, said transition section being provided with expansion flap valves. 23. Apparatus according to claim 20, in which at least one burner is provided in the wall of said combustion chamber for initial heating of said combustion chamber. 24. Apparatus according to claims 20 or 23, in which at · least one burner is provided in said header of said combustion chamber for initial heating of said combustion chamber. 25.- Apparatus according to claim 20, in which said combustion chamber is provided with an apparatus assembly for heating or cooling of said combustion chamber. 26. Apparatus according to claim 25, in which said appa ratus assembly for heating or cooling said combustion chamber eos? prises piping in. contact with the exterior of the combustion cham ber walls. \^ .27. Apparatus according to claim 20, in which said ante chambers are of circular cross-section and flare outwards towards their outlets into said combustion chamber. 28. Apparatus according to claim 20, in which a distribution chamber is provided on the exterior of said header for the combustion supporting gas, said distribution chamber having a supply conduit arranged to discharge thereinto and being connected to said ante-chambers of said header for the supply of combustion supporting gas thereto. 29. Apparatus according to claim 20, in which said separator apparatus comprises at least one cyclone separator arranged as a pre-separator and filter apparatus arranged to operate as final separator. 30. Apparatus according to claim 29, in which said filter apparatus is a multi-chamber filter. 31. Apparatus according to claim 20, in which said antechambers are arranged for operation at a temperature of at least 600°C. 32. Apparatus according to claim 20, designed for operation with liquid hydrocarbon raw material, in which a distributing chamber for the combustion supporting gas is provided having openings into said ante-chambers of said header in each of which a spray nozzle is arranged which is provided with a tube connected with a feed conduit for said liquid hydrocarbons,, said 4356 33. Apparatus according to claim 32, in which in said tube of each of said spray nozzles a control pump having an out put independent of pressure is provided. 34. Apparatus according to claim 28, in which a diffuse is shiftably mounted in openings between said distributing chambe and said ante-chambers. 35. Apparatus according to claim 32, in which said spra nozzles are arranged so that they may be drawn back during the pre-heating period of said combustion chamber or for replacement of a nozzle. 36. Apparatus according to claim 20, designed for operation with gaseous hydrocarbons as raw material, in which a mixi apparatus for mixing gaseous hydrocarbon raw material with an oxygen-containing combustion-supporting gas is provided in the supply conduit leading to said ante-chambers, said mixing apparatus being a tubular apparatus having a tubular portion of a form providing a homogenizing passage, two feed legs leading thereto and an anti-backfire portion in series with said homogenizing portion and having a filling of packing material providing interstitial space for gas flow. 37. Apparatus according to claim 36, in which said mixi apparatus is privided in said supply conduit ahead of a preheatin heat exchanger. . 38. Apparatus according to claim 36, in which means are provided maintaining the pressure in said mixing apparatus at les than 0.5 atm. below atmospheric pressure. 39. Apparatus according to claim 29, in which said sepa rator apparatus includes a conveyor provided with a built-in