Abstract: Carbon black includes primary particles having an average particle size of 15 to 40 nm, microprotrusions having an average length of 2 to 10 nm being formed on a surface of the primary particles. A method for producing carbon black includes introducing an oxygen-containing gas and fuel into a fuel combustion zone, mixing and combusting the oxygen-containing gas and the fuel to produce a high-temperature combusted gas stream, introducing a raw material hydrocarbon in a first stage of a raw material introduction zone and introducing the raw material hydrocarbon and an oxygen-containing gas in a second stage of the raw material introduction zone while introducing the high-temperature combusted gas stream into the raw material introduction zone to produce a carbon black-containing gas which is introduced into a reaction termination zone while spraying a coolant.

Abstract: Carbon black includes primary particles having an average particle size of 15 to 40 nm, microprotrusions having an average length of 2 to 10 nm being formed on a surface of the primary particles. A method for producing carbon black includes introducing an oxygen-containing gas and fuel into a fuel combustion zone, mixing and combusting the oxygen-containing gas and the fuel to produce a high-temperature combusted gas stream, introducing a raw material hydrocarbon in a first stage of a raw material introduction zone and introducing the raw material hydrocarbon and an oxygen-containing gas in a second stage of the raw material introduction zone while introducing the high-temperature combusted gas stream into the raw material introduction zone to produce a carbon black-containing gas which is introduced into a reaction termination zone while spraying a coolant.

Abstract: A port liner assembly comprises a tubular liner embedded in a cylinder head block as its moulding so as to be integrally formed into a heat-insulation wall surrounding an exhaust port formed in said cylinder head block, said tubular liner consisting of an outer tube and an inner tube spaced inside of said outer tube.