Sodium nitrite manufacturers introduce their production process

Sodium nitrite manufacturers introduce their production process

Nowadays, the application of sodium nitrite in our daily life can be said to be everywhere, so do you understand the production process of sodium nitrite in our daily life? Please follow the editors of sodium nitrite manufacturers.

Sodium nitrite production process

The 32% (mass fraction, the same below) lye from the electrolysis process enters the I-effect, II-effect, and III-effect evaporators in sequence through the pump for evaporation. The medium-pressure steam from the heat source of the thermoelectric boiler first enters the III-effect evaporator as the heat source, the secondary steam generated is the II-effect heating, and the secondary steam generated by the II-effect is the I effect heating, and the heat of the entire evaporation system is fully recycled. Finally, the secondary steam is condensed and recycled. 48% of the lye in the Ⅲ effect evaporator is sent to the solid alkali unit to continue concentration. In the solid alkali plant, the first concentration is that 48% of the lye enters the pre-concentrator. After coming out of the pre-concentrator, the mass fraction is about 62%, and then pumped to the final concentrator; after the second concentration, use The effect of gravity enters the flash tank for flashing from top to bottom, and finally cools to produce 98.5% sodium nitrite. The heat carrier in the solid alkali plant is molten salt (a mixture of potassium nitrate, sodium nitrate, and sodium nitrite). Natural gas heats the molten salt to above 420 ℃. The molten salt is sent to the final concentrator by a molten salt pump for heating The secondary steam generated by the concentrator is sent to the pre-concentrator for reuse. In the evaporation and solid alkali installation, the alkali and heat are reverse flow heat exchange, which is beneficial to more fully use the heat and achieve the purpose of energy saving and environmental protection.

The waste alkali is the unqualified alkali when the device is abnormal. They are the molten alkali in the arc pot and the U-bend of the sodium nitrite machine when the machine is stopped. This part of alkali cannot meet the product quality requirements, and is stored in a centralized manner after recovery. Alkali easily absorbs moisture and dissolves when exposed to air, and reacts with carbon dioxide in the air to form sodium carbonate and becomes ineffective. This process does not have high requirements for the content of lye impurities, but it has requirements for the concentration; and the waste alkali piled up just meets the requirements. Therefore, the recovered waste alkali is re-dissolved to produce lye that meets the usage conditions of acetylene and sewage stations to achieve the purpose of waste utilization.

Transformation method: add a new tank (specification 2 800 × 3 000) on the west side of the 32% alkali tank in the first phase of evaporation, as a soda tank, make a platform and guardrail around the tank; add an alkali pump (little old), Lead the alkaline solution with qualified concentration to the pipeline to the acetylene and sewage station, and install a valve to control. Alkaliized water uses secondary steam condensate in the solid alkali process, while adding a DN25 steam line to the tank for stirring to accelerate the dissolution of waste alkali.