Application analysis of new technology about purging large sulfur recovery unit with hot nitrogen

In order to ensure the SO₂ concentration in the exhaust gas of sulfur recovery unit reaching the standard during the shutdown process, the existing technologies of flue gas emission reduction were investigated.After comparing and analyzing the advantages and disadvantages of the technologies, the new technology of hot nitrogen purging sulfur was chosen to carry out pilot test finally.By simple technological transformation of sulfur and tail gas treatment equipment, the new technology of hot nitrogen purging sulfur was applied, which the sulfur purging and passivation was crossed.Since there had no liquid sulfur flowing from the third grade sulfur condenser, the tail gas of Claus was directly cut into the tail gas incinerator.The passivation process didn't consume alkaline liquid or produce waste water, and the SO₂ mass concentration in flue gas was less than 600 mg/m³(0 ℃, 101.325 kPa), which could meet the requirements of environmental control index.