Hard carbon black reaction furnace

The invention provides a hard carbon black reaction furnace. The hard carbon black reaction furnace comprises a burner, a combustion chamber, a throat pipe section, a reaction section, a reaction termination quenching section and a carbon black flue gas retention section which are connected in sequence. Through reasonable design of the length of a first straight pipe section of the combustion chamber, fuel is fully combusted, so the fuel is saved; the throat pipe section is designed with a double-row raw material oil gun, so raw materials are sprayed into a reaction furnace to be atomized better; by adoption of inclined plane reducing in the reaction section, the carbon black flue gas flow of a reaction is accelerated again, and a shearing force and the degree of cracking are increased, sothe reaction is uniform and violent, and produced carbon black particles are more uniform; the reaction termination quenching section is combined with the reaction section to expand again, so the structural degree of carbon