GB854750A - Process and apparatus for production of carbon black - Google Patents

Abstract

<PICT:0854750/III/1> In the production of substantially tar-free furnace black, i.e. black having a photelometer of at least 80, the black produced is quenched by the injection into the furnace of a liquid coolant at a point immediately after that at which the black become substantially tar-free. The liquid coolant may be water or a liquefied normally gaseous hydrocarbon. The black is preferably cooled to a temperature below 2,000 DEG F., more preferably below 1,500 DEG F. Further cooling, e.g. to 1,200 DEG F. may be effected by indirect heat exchange and/or by further injection of liquid coolant. The black may be produced as shown by the decomposition of a substantially linear stream of make material in a surrounding spiral stream of hot combustion gases in a substantially cylindrical furnace comprising a combustion chamber of diameter greater than its length followed by a reaction chamber coaxial with the combustion chamber of smaller diameter. The liquid coolant may be injected inwardly, radially or at a slight angle to the radius, from a plurality of evenly spaced points, e.g. 2 or 4, at the periphery of the reaction chamber (Figs. 4 and 10, not shown), or may be injected outwardly from a point at the axis of the reaction chamber (Figs. 12 and 13, not shown). The point of injection may be varied by having several series of inlets in the former case and a longitudinally adjustable inlet in the latter case. The liquid coolant inlets may be water cooled. The make material may be normally solid, liquid or gaseous. Methane, ethane, propane, butane, naphtha and an aromatic gas oil of boiling range 400-700 DEG F. are specified. All, or a portion of the reactant may be preheated before injection. The injection pipe may be water cooled and may additionally be cooled by the injection of air and/or steam into the furnace around the pipe. The injection nozzle may be open-ended, may have a single restricted orifice, or may have a ring of orifices adapted to form a spray having an included angle of 10-50 degrees (Figs. 9, 7 and 5 respectively, not shown). The nozzle may project through the inlet wall of the furnace, may be flush therewith, or may be recessed therein. The hot combustion gases may be produced by the combustion at a burner (Fig. 3, not shown) of a fuel and oxygen, air, or air enriched with oxygen. The fuel may be normally solid, liquid, e.g. fuel oil, or gaseous, e.g. hydrogen, carbon monoxide, methane, ethane, propane, or butane. Either or both of the fuel and oxygen-containing gas may be preheated. The tangential air and fuel rate may be 185,000-360,000 c.f.h. and 12,330-24,000 c.f.h. respectively. Specifications 621,031 and 679,818 are referred to.