Urea Reactor Tray Revamping

The urea synthesis column is one of the key equipments which are used in urea production. The reaction of urea synthesis proceeds in the column. Both the conditions of synthesis and the internal construction of the column have influenced the inversion rate of synthesis and energy consuming of the system. By analyzing and studying the technology of reconstructing internal construction of the column to improve the inversion rate of synthesis, the thesis presented reconstructing the schema of Snamprogeetti craft column producing 520,000 ton of urea per year.The reactions have proceeded under high temperature and high pressure in column, and there are very complex relation between the reactions and the equilibrium. So the thesis adopted the Lemkowitz thermodynamics model of the urea synthesis system and multiple reactors in series model to make numeric simulation and studying and analyzing the results of numeric simulation prove that the inversion rate of dioxide can be improved under the conditions which trays are properly increased in the bottom of column and others have no changing. At the same time, by analyzing the mechanical of synthesis and mass transfer between gas phase and liquid phase and the effects of the inversion rate of the synthesis reaction, the text adopts the tray of high mass transfer rare between gas phase and liquid phase, which can improve the inversion rate of dioxide.The thesis adopted the high efficiency wave tray to reconstruct the tradition tray of urea synthesis column, which has strengthened heat and mass transfer. By taking full advantage of the room of the bottom of reactor, the number of trays are properly increased, which can have more ideally staying time contribute and more enough reacted and improve the reaction of synthesis reactor.According to reconstructing results, it was prove that the inversion rate of dioxide has been increased by 2% and the steam of middle pressure consuming has been decreased 5 ton per hour under other conditions no changing.