GB850323A - Process and apparatus for producing carbon black - Google Patents

Abstract

Carbon black is produced by the combustion of hydrocarbons in a furnace which comprises a cylindrical combustion reaction chamber of diameter at least equal to its depth bounded by a side wall and by parallel inlet and outlet walls normal to the side wall, the inlet wall having an opening coaxial to the chamber containing a hydrocarbon injection <PICT:0850323/III/1> conduit having a nozzle which produces a hollow spray cone the angle of which is at least 50 degrees, and, at the periphery a plurality of burners for producing flames travelling perpendicularly from the inlet wall towards the outlet wall and along the side wall across the path of the spray cone, the outlet wall having an opening disposed centrally therein leading to a cooling chamber. In the figure the hydrocarbon inlet conduit 23 passes through an opening 15 in the inlet wall 13 of the combustion chamber 12 which has a depth of 1/2 -1 x its diameter. Conduit 23 terminates in a nozzle 27 fitted with a perforated disc for producing a hollow spray cone of angle at least 50 DEG C. say 50-150 DEG C. A plurality of burners 14 supplied with hydrocarbon fuel and air by 22 are arranged at the extremities of the inlet wall 13. Orifice 16 which preferably has a cross-sectional area of 3-10% the area of the outlet wall 26 leads directly into quenching chamber 17 which is preferably cylindrical and has a diameter less than that of the combustion reaction chamber but greater than that of the outlet 16, and has a volume 10-50% that of the combustion chamber 12 and is provided with openings 24 near the outlet orifice, having pipes with spray heads 25 to spray cooling fluid into the stream of carbon laden gases, quenching them within a period of 0.005-0.01 seconds. Cooled reaction products pass from 17 through 18 to a carbon collector. In operation a combustible hydrocarbon e.g. a liquid highly unsaturated or aromatic substance, is sprayed into the combustion chamber through 27 while fuel e.g. a hydrocarbon oil or gas for example natural gas is introduced through burners 14, with sufficient air to permit complete combustion of the fuel and at least half of the hydrocarbon. The rates of flow of hydrocarbon, fuel and air are regulated so as to provide a positive pressure of at least 20 inches of water in the combustion chamber and to maintain an outlet flow from the chamber of 300-700 cu.ft./cu. foot/min. Under these conditions the hydrocarbon is decomposed within the chamber within a period of 0.013-0.03 seconds. Specification 673,155 is referred to.