Patent ID: 6120740
Filing Date: 2000-09-19
Classification: B01D,B01J,C07C,Y02P

Abstract:
A method for in-situ modernization of a reactor for urea synthesis at high pressure and temperature wherein a co-current flow of a gaseous phase and a liquid phase takes place in a vertical, tubular shell of the reactor in which is supported a plurality of superimposed horizontal perforated plates having a plurality of perforations in mutually spaced relationship, the method comprising the steps of replacing at least two adjacent existing perforated plates with corresponding perforated plates having respective mutually offset openings for liquid flow which are larger than said perforations for gas flow, each of said plates disposed in close proximity to said shell to provide a small peripheral gap to provide passivation against corrosion between said plate and said shell and having a downwardly depending collar extending around a perimeter of said plate.