Introduction to Nitrogen Generators for Powder Metallurgy

In the sintering process of powder metallurgy, hydrogen is used as a reducing gas and nitrogen as a protective gas to reduce and protect iron powder. Hydrogen is generally provided by ammonia decomposition for hydrogen production, but the hydrogen concentration from this method is too high. Therefore, nitrogen produced by nitrogen generators is used to dilute the hydrogen from ammonia decomposition, reducing the hydrogen content to 5%-15%. This significantly lowers operating costs. The main applications of nitrogen generators for powder metallurgy include: protective gas for continuous casting, continuous rolling, and steel annealing; nitrogen for top and bottom combined blowing in converter steelmaking, sealing of converters, sealing of blast furnace tops, and gas for pulverized coal injection in blast furnace ironmaking.

Role of Nitrogen Produced by Powder Metallurgy Nitrogen Generators in Powder Metallurgy

1.Purging. During carburizing and nitriding processes, nitrogen produced by nitrogen generators is commonly used to purge and exhaust the furnace, seal the furnace door with a gas curtain, and prevent oxidation during cooling after carburizing. The nitrogen purity is typically above 99.5%.

2.Quenching protection. After continuous operation of a quenching furnace for about a week, accumulated carbon needs to be burned off inside the furnace. If the furnace temperature during carbon burning exceeds 960°C, nitrogen must be immediately introduced to remove oxygen and extinguish the fire to prevent accidents.

3.From a cost perspective, using nitrogen produced by nitrogen generators, which extracts nitrogen from the air, is low-cost, making it the most economical option as a protective gas.

4.Sintering protection. Combining nitrogen with appropriate temperature and time allows each stage of the sintering process to achieve high efficiency and economic goals.

Working Principle of Nitrogen Generators for Powder Metallurgy

Nitrogen generators for powder metallurgy operate on the pressure swing adsorption (PSA) principle, using air as the gas source and employing PSA technology to separate air and obtain nitrogen. Purified compressed air enters the bottom of the adsorption tower, which is filled with carbon molecular sieve. This molecular sieve adsorbs most of the oxygen, achieving oxygen-nitrogen separation under the effect of pressure swing adsorption. Due to the selective adsorption characteristics of the molecular sieve, oxygen is adsorbed within the carbon molecular sieve, while nitrogen is enriched in the gas phase and output as the product. The system is equipped with two adsorption towers: one for adsorption and oxygen production, and the other for desorption and regeneration, alternating cycles to continuously produce nitrogen.

Common models of nitrogen generators for powder metallurgy include: 15 Nm3/h, 20 Nm3/h, 30 Nm3/h, 40 Nm3/h, 50 Nm3/h, 60 Nm3/h, 80 Nm3/h, 100 Nm3/h, and so on. (Our company can produce units with flow rates ranging from 3 to 5000 Nm3/h and purities from 95% to 99.9995%. Welcome to inquire.)