Water reducing agent industrial production process

(1) Naphthalene: Naphthalene is solid at room temperature, and it needs to be put into the naphthalene chemical kettle for heating and melting.
(2) Sulfonation: The sulfonation process is to add concentrated sulfuric acid to the sulfonation kettle to react with it to produce naphthalene sulfonic acid. There are two types of naphthalenesulfonic acid: α-naphthalenesulfonic acid and β-naphthalenesulfonic acid.
(3) Hydrolysis: Since α-naphthalenesulfonic acid is produced during the sulfonation reaction, its presence is not conducive to the condensation reaction, so water needs to be added to hydrolyze α-naphthalenesulfonic acid.
(4) Condensation: After the hydrolysis reaction is completed, formaldehyde is added dropwise to the condensation kettle, and reacts with β-naphthalene sulfonic acid to form a naphthalene-based sulfonated formaldehyde condensate.
(5) Neutralization: The material after condensation enters the neutralization kettle, and liquid caustic soda is added dropwise to neutralize the excess sulfuric acid in the sulfonation reaction. Stop dropping when the pH reaches 7-9.
This control system mainly monitors the production status of four different reaction kettles and their batching tanks. The production line can carry out 4 lines of production at the same time. Taking production line A as an example, there are one naphthalene reactor and two sulfonation reactors. , four condensation kettles and one neutralization kettle. Each reaction kettle has a feed valve, a discharge valve, an evacuation valve, a hot oil feed valve, a cooling water valve, a steam pressure valve, a steam flushing valve, etc., and the reaction The kettle is also equipped with a raw material tank. The two sulfonation kettles share a sulfuric acid tank. Each two condensation kettles are equipped with a set of formaldehyde tanks and dilution water tanks. Each condensation kettle has a hydrolysis water tank, and the liquid alkali tank is responsible for neutralization. Liquid caustic soda is added dropwise into the kettle. The specific process flow chart is shown in the figure.
Application status:
Naphthalene-based water reducing agent is a concrete additive invented by Dr. Kenichi Hattori of Japan in 1962. It is a chemical synthesis product of naphthalene sulfonate formaldehyde condensate, using industrial naphthalene, concentrated sulfuric acid, formaldehyde and alkali as the main raw materials. Adding naphthalene-based water-reducing agents to concrete can not only increase the strength of the concrete, but also improve its various properties, such as abrasion resistance, corrosion resistance, permeability resistance, etc. Therefore, naphthalene-based water-reducing agents are widely used in Highways, bridges, tunnels, docks, civil construction and other industries.