Patent ID: 7625527

Claim:
A carbon black reactor comprising: a combustion zone for generating a combustion gas by burning a mixture of a hydrocarbon fuel and an oxygen containing gas; a reaction zone having two or more points to introduce feedstock arranged therein for producing a carbon black containing flow by contacting said combustion gas with a feedstock introduced in a plurality of divided flows to thermally decompose or incompletely combust the feedstock; and a quench zone for stopping a carbon black growth reaction by injecting a coolant to said carbon black containing flow, wherein: the combustion, reaction, and quench zones are arrayed laterally in order, the combustion zone extending just to an upstream end of the reaction zone containing the feedstock introduction part, and the cross-section shape of the area from a first of the two or more points to a last of the two or more points in said reaction zone is not a circle nor a polygon, the cross-section shape is selected from the group consisting of a shape formed of a combination of semicircle or circle segments and elliptical segments, a shape formed of semicircle or circle segments and open curves, a shape formed of semicircles and straight lines, a shape formed of circle segments and straight lines, a shape formed of a combination of curved line and curved line, a shape formed of a combination of curved line and straight line, a shape of ellipse, and a shape formed of elliptical segments and straight lines, and a ratio of a longest axis of said cross-section shape to a shortest axis thereof is 1.5-20.