Patent ID: 6254840
Filing Date: 2001-07-03
Classification: B01J,C07C

Abstract:
A reactor for preparing urea from ammonia and carbon dioxide comprising a reactor shell defining a reactor wall, a cylinder, and two perforated trays, an upper tray and a lower tray, the separation between the trays defining a tray spacing distance, whereinthe trays are configured to provide a gas transport path through the reactor, the gas transport path comprising a plurality of perforations in each tray, the perforations being arranged in a central portion of the tray and surrounded by an outer unperforated portion of the tray, the outermost extension of the unperforated portion defining a tray edge;the trays are further configured to provide a liquid transport path through the reactor, the liquid transport path comprising at least one opening for each tray selected from a group consisting of an opening formed in the tray, the opening being substantially larger than the perforations and located in the outer unperforated portion of the tray, and an opening formed between the tray edge and the inside of the reactor wall,the upper tray further including a downwardly extending flange formed on the underside of the tray and outwardly of the perforations, for maintaining a gas cushion under the tray, andthe lower tray further including an upwardly extending rim formed on the top side of the tray and surrounding the perforations in the tray andthe cylinder positioned between the upper tray and the lower tray, wherein the diameter of the cylinder is both smaller than the downwardly extending flange of the upper tray and larger than the upwardly extending rim on the top side of the lower tray, and further wherein the height of the cylinder is 40-80% of the tray spacing distance.