GB855802A - Improvements in or relating to the manufacture of carbon black - Google Patents

Abstract

In the manufacture of carbon black, gaseous, vaporous, or atomized liquid hydrocarbon material is introduced into one end of a cylindrical furnace through a tube, and a gas which reacts with the hydrocarbon material to produce carbon black by pyrolysis and/or partial combustion is introduced through an annular passage which surrounds and is coaxial with the tube and terminates as an angular annulus leading outwards in the direction of gas flow, the arrangement being such as to cause the gas introduced through the annular passage to be directed on to the furnace wall before it mixes to any substantial extent with the hydrocarbon material. The gas introduced through the outer tube may be free oxygen-containing gas, e.g. air, and the ratio of velocity of hydrocarbon material to air may be 1.3:1. The outer tube may contain the spiral member of Specification 799,145 to give the air an angular swirl. A burner assembly may consist of a central feed pipe feeding hydrocarbon into a brick cone forming the entrance of the furnace, and a metal or refractory cone is secured to the outside of the pipe with the open end facing downstream and in line with the end of the feed pipe. The angle of the cone may be 20-90 degrees. The annular air passage surrounding the feed pipe may be the wall of the housing, or may be a pipe ending at the apex of the cone of the feed pipe, or coned at the same angle as that cone but stopping short of the inner cone. An annular passage may be provided, between the hydrocarbon feed pipe and the outer gas pipe, for the supply of air to keep the burner tip free of carbon, or for the supply of fuel in which case the passage may be open-ended or end in jets. The length of feed pipes should be not less than 10 pipe diameters to ensure streamline flow. The burner assembly may be withdrawn through a gas lock into a isolatable chamber to permit adjustment and return without closing down the furnace.