Method for modernizing a urea production plant

摘要

A method for the modernisation of a plant for urea production of the type comprising a reactor (2) for urea synthesis, a stripping unit (3) with carbon dioxide and at least one vertical condensation unit (4) of the film type, foresees the provision of means (36) for feeding a major portion of a flow comprising ammonia and carbon dioxide in vapour phase leaving the stripping unit (3) to the condensation unit (4) and the provision in said condensation unit (4) of means (37) for subjecting to substantially total condensation such major portion of the flow comprising ammonia and carbon dioxide in vapour phase, obtaining a flow comprising urea and carbamate in aqueous solution, then fed to the reactor (2) for urea synthesis. Thanks to the present method of modernisation, the efficiency of the condensation unit (4) is remarkably improved, thus permitting an increase of its capacity.