| The Urea synthesis reactor is the key equipment of urea synthesis in Jianfeng Fertilizer plant Since it has been run from 1993, due to the shortcomings of the original design, CO2 conversior rate is lower than the design, (the design value is 67%, the actually highest value was 63%, th average was 60%), and increases the caloric burden of the stripper (300E01), meanwhile the desigi area of 300E01 is not enough for heat exchange, and the outlet liquid temperature is low. It cause the burden move to downstream equipments and increases the decomposition recovery burden o the following equipments. Because of the low rate of the CO2 conversion, the steam consumptio: increases for decomposition and results in the low efficiency of stripping tower and the fall c stream of the condenser of high pressure AM.Therefore, if the conversion rate of CO2 in urea converter can be increased, and the syntheti efficiency, also the yield of urea daily will be increase that bring high economic efficiency fo Jianfeng Fertilizer plant.In this paper, by means of the chemical engineering thermodynamics, transfer phenomenor fluid dynamics, the chemical reaction engineering, the theory of chemical reactor, and ure synthesis theory, incorporate the original design of urea reactor, detailed analyse has bee performed for the urea reactor. Although it is quick for AM synthesis reaction and is slow from AN to urea, in actually, AM is synthesized by gas phase of CO2 and liquid phase of ammonia, chemicf reaction only happen in liquid phase, its macro reaction velocity not only have relation with velocity of chemical reaction, but also with diffuse velocity of air phase material diffusing to th interface of air liquid phase relevantly. The theoretic analyse and actual temperature distribution c urea converter can get the same result that the macroscopic reaction speed of AM synthesis i controlled by diffuse also influenced by the effect of macro view velocity of AM synthesis.Based on the relevant theory and the J.W.Gibbs phase rule analyse of the chemical equation know the Independent variable of urea synthesis is 3; the analyse to urea reactor, Shows that th conversion rate of CO2 is not only have relation with 3 independent variables, but also with th flowing state and the purity of the materials, with the staying time of material inside the containe with mixture of the air liquid phase materials, and with the velocity of heat and quality transm between materials. This paper has indicated the poor design of previous structure design, ancarried out the improvement for increasing the rate of CO2 conversion,1 , Increase properly the ratio of the ammonia /carbon;2 , Decrease the ratio of the water /carbon;3 , Choose the optimum operation temperature;4 , Increase the feed materials purity and use about 0.3% pure oxygen to replace the 1% air; 5, Change the originally reactor's plate structure to increase air liquid mixture moreefficiently, adjust the staying time and accelerate the transfer of heat and quality;6 , Add pre-mixture reactor.This paper has performed feasibility study economically and technically for urea reactor optimum, also analysed the corrosion and its countermeasure of the circumstance of new operation condition and new synthesis plate. Give the improvement direction of the urea reactor for Jianfeng Fertilizer plant.
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