Nitric acid is a kind of strong acid chemical raw material with strong oxidizability and corrosiveness commonly used in chemical industry. It has strong oxidizability. The higher the concentration is, the stronger the oxidizability is, the higher the concentration is, and the more volatile it is. So what vacuum pump is suitable for industrial nitric acid transportation? How to choose?
Most of the general metals are destroyed by rapid corrosion in nitric acid. Stainless steel is the most widely used nitric acid resistant material, which has good corrosion resistance to all concentrations of nitric acid at room temperature. It is worth mentioning that the corrosion resistance of molybdenum containing stainless steel to nitric acid is not only not better than that of ordinary stainless steel, sometimes even worse. For high temperature nitric acid, fluoroplastic alloy is usually used, which is economical and durable.
Nitric acid vacuum pump selection:
Because nitric acid has no obvious corrosion on stainless steel, many users first consider using stainless steel pump when selecting nitric acid vacuum pump, but also according to the actual conditions, we recommend the following nitric acid delivery pump:
1. If the concentration of dilute nitric acid is relatively low, the 2BV stainless steel corrosion-resistant multistage chemical pump without leakage can be selected. This series of pumps adopt multistage structure, which is highly efficient, energy-saving and leak free. It is specially used to transport corrosive media such as nitric acid, sulfuric acid, hydrochloric acid and so on.
2BV stainless steel corrosion-resistant nitric acid pump is a single suction, multi-stage, section type corrosion-resistant chemical centrifugal pump, which is suitable for conveying corrosion-resistant liquid without solid particles. The transmission medium temperature is – 20 ℃ ~ 105 ℃, and the allowable inlet pressure is 0.6MPa. The shaft is a fully sealed structure, ensuring no contact with the medium, no corrosion and long service life. The hydraulic model of high-efficiency and energy-saving products recommended by the state is adopted, which is in the leading position of technology in the industry. It has the advantages of high efficiency, wide performance range, stable operation without leakage, low noise, convenient installation and maintenance, and is widely used in petroleum, chemical, paper, food, pharmaceutical and other industries.
2. If it is 98% concentrated nitric acid, the 2be type stainless steel corrosion-resistant vacuum pump can be selected. The overflow parts of this series of pumps are all made of fluoroplastics (poly perfluoroethylene propylene). The mechanical seal adopts the bellows type mechanical seal filled with tetrafluorocarbon material, which can effectively prevent the leakage of concentrated sulfuric acid. The selected motor power needs to be increased, The specific can be calculated according to the rated shaft power of the pump when delivering concentrated nitric acid.
The special chemical pump for 2be stainless steel corrosion-resistant vacuum pump is designed according to international standards. The pump body is lined with metal shell and poly perfluoroethylene propylene (F46). The pump cover, impeller and shaft sleeve are all made of metal insert and wrapped with Fluoroplastic. The shaft seal is made of external bellows mechanical seal. The static ring is made of 99% alumina ceramic or silicon nitride. The dynamic ring is made of tetrafluoroethylene filling material, which is corrosion-resistant and wear-resistant It is suitable for conveying any concentration of sulfuric acid, hydrochloric acid, acetic acid, hydrofluoric acid, nitric acid, aqua regia, strong alkali, strong oxidant, organic solvent, reducing agent and other harsh conditions of strong corrosive medium, and is one of the strong corrosion-resistant equipment.