| 摘要 |
1308339 Carbon black CABOT CORP 2 April 1970 [4 April 1969] 15609/70 Heading C1A In the preparation of carbon black by the pyrolysis of a hydrocarbon feedstock in a high temperature environment created by the combustion of a fluid fuel by means of an oxygen rich oxidant gas, the fuel is injected, e.g. by line 24 into a combustion zone 16 where it is burned at a pressure of at least 3 p.s.i.g. by admitting oxygen rich gas, e.g. through orifices 32 either tangentially (Fig. 1) or radially/obliquely (Fig. 5, not shown) to form either a spin stabilized or jet stabilized flame, the combustion products accelerating through chamber 16 until at a point where the kinetic head is at least 3 p.s.i., e.g. at orifices 34, the liquid hydrocarbon feedstock is transversely injected into the combustion stream as small penetrating jets in an amount sufficient to provide a temp. level of 4000‹ F. and the creation of carbon black forming conditions, when after passing through zone 46 (Fig. 4) for sufficient time to form carbon black, the product is quenched, e.g. with jets 48 and the carbon black separated. The oxidant gas may contain at least 50 mol. per cent most preferably 90 mol. per cent of molecular oxygen and the fuel gas used may contain a substantial proportion of hydrocarbons. The combustion reaction may be adjusted so as to effect a heat release rate of at least 30 x 10<SP>6</SP> BTU's per hour per cu. ft. of combustion space. The combustion may be carried out at between 5 and 50 p.s.i.g. preferably between 10 and 30 p.s.i.g. and the temperature level during the reaction preferably reaches 4500‹ F. The proportion of oxidant to fuel may be adjusted to provide from 70% to 500% of the oxygen theoretically required for complete combustion and the amount of feedstock injected is adjusted to give a theoretical overall per cent combustion of between 10% and 50%. The feedstock may be injected at that point where the kinetic head is equivalent to at least 5 p.s.i. and the jets may be discharged through orifices between 0À01 and 0À04 inches in diameter. The pressure behind the jets may be at least 100 p.s.i. and the quenching step may take place from 5 to 100 milliseconds after the injection. Preferably after injection, the gas stream is allowed to expand to a much greater cross-sectional area. The walls of the furnace used may be constructed of a material of high thermal conductivity, e.g. a metal, and may incorporate cooling means. The fuel may be introduced in a series of parallel streams, e.g. via plate 28 in Fig. 1, or the fuel and the oxidant gas may be introduced through respective members of pairs of intersecting nozzles. |
