| 摘要 |
<p>PURPOSE:To prepare urea, economically, in an industrial scale, with reduced thermal cost, by reacting NH3 with CO2 in a reactor, extracting the urea-containing liquid phase and the gaseous phase continuously from the reactor, cooling and condensing the gaseous phase, and utilizing the heat of condensation as the heat for the concentration of the aqueous solution of urea. CONSTITUTION:Ammonia gas containing oxygen for corrosion protection of the apparatus is supplied to the pump 2 through the supply tube 3, and introduced into the reactor 1 through the inlet tube 4. CO2 gas is supplied to the compressor 5 through the tube 6, and introduced into the reactor 1. The liquid phase containing urea produced by the reaction of ammonia and CO2 is extracted continuously from the reactor 1 through the overflow tube 14. On the other hand, the gaseous phase containing steam, NH3, CO2, etc. is taken out from the top of the reactor 1, and introduced into the condenser 10 through the outlet tube 9. The gas is cooled and condensed by the thermal medium in the heat-exchange tube 13, and the heat received by the indirect cooling is transferred through the the heat exchange tube 20 to the evaporator 19, in which the urea solution in the liquid phase is concentrated by the received heat to obtain concentrated urea solution from the outlet tube 21.</p> |
