FIELD: urea production methods.
SUBSTANCE: invention relates to a method for the production of urea. The method includes: a synthesis step in which urea is synthesized from ammonia and carbon dioxide to obtain a solution for urea synthesis; a decomposition step in which, by heating the urea synthesis solution obtained in the synthesis step, ammonium carbamate is decomposed and a gas mixture containing ammonia and carbon dioxide is separated from the urea synthesis solution to obtain a urea synthesis solution with a higher concentration of urea than with the synthesis solution obtained in the synthesis step; a condensation stage in which, using an immersion condenser including a shell-and-tube heat exchange structure including a U-tube, at least a portion of the gas mixture obtained in the decomposition stage is absorbed and condensed in an absorbing medium in the annulus, and steam is generated in the tube space using the heat released during condensation; a recirculation stage in which at least a portion of the liquid is recirculated to the synthesis stage, said liquid being produced in the annular space in the condensation stage; and a water supplying step of supplying water to the tube space of the immersion condenser at a mass flow rate that is three or more times the mass production rate of steam generated in the immersion condenser.
EFFECT: proposed method makes it possible to reduce the temperature distribution in the immersed condenser.
9 cl, 2 dwg
