| 摘要 |
<p>A method for passivating the surface of strippers of urea manufacturing plants, where the temperatures are very high, where the pressures range from 120 to 240 Kg/cm<Sup>2</Sup> and where the effluent process flow from the synthesis reactor undergoes one or more falling-film evaporations, preferably in countercurrent with a driving gas consisting of NH<Sub>3</Sub> or C0<Sub>2</Sub>, characterized by the fact that the passivation is carried out by means of a synergistic combination of oxygen, preferably injected into the bottom of at least one stripper, and of a second passivating agent, preferably injected into the process flow entering the head of at least one stripper, wherein said second passivating agent is injected in the liquid state or as a liquid solution, before or contemporaneously to the start of the evaporation.</p> |
