Continuous naphthalene sulfonation reaction process

The invention discloses a continuous naphthalene sulfonation reaction process which sequentially comprises the following steps: feeding sulfuric acid and refined naphthalene into a primary sulfonationreactor, enabling a molar ratio of the primary sulfuric acid feed to refined naphthalene feed to be 1:(1-1.1), and reacting for 40-50 minutes; feeding secondary sulfuric acid feed into a secondary sulfonation reactor, enabling a molar ratio of the secondary sulfuric acid feed to the primary sulfuric acid feed to be 1:(1.9-2.1), and mixing and reacting for 40-50 minutes; feeding third-time sulfuric acid feed into a third-stage sulfonation reactor, enabling a molar ratio of the third-time sulfuric acid feed to the primary sulfuric acid feed to be 1:(5-6), and mixing and reacting for 40-50 minutes; enabling the materials to enter a fourth-stage sulfonation reactor and a fifth-stage sulfonation reactor to respectively react for 60-80 minutes. The whole sulfonation process adopts continuous totally closed production,