小尿素预蒸馏工艺流程的改进及效果

Improvement on Pre distillation Process in Small Scale Urea Plants and Its Results

预蒸馏工艺流程是水溶液全循环法年产４．０万ｔ尿素装置通用设计中的一项主要改进，对于稳定生产、节能降耗及发挥设备的能力起了重要作用，成为小尿素工艺独有的技术特点。但该技术尚存在着有待于完善提高和不断改进的潜力。基于这种想法，我厂对原预蒸馏工艺流程进行了改进，并获得成功。生产实践证明。

The pre distillation process is a major item of improvement in the general design of 40000 t/a urea units based on the aqueous solution total recycle process, plays an important role in the stabilization of production, saving in energy, reduction in consumption and full utilization of equipment capacity, and is a unique technical feature in the urea process in small units.Nevertheless, there is yet potentiality for its perfection and continual improvement. With this view in mind, the authors try to improve on the original pre distillation process in this plant and obtain successful results. Production practice proves the results of improvement are remarkable.