【November 8】One question per day
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Why is a booster installed in medium-sized urea plants? What is the purpose?
Increasing the pressure of the two-stage evaporation and condensation system raises its condensation temperature accordingly, thereby maintaining the vacuum level in the two-stage evaporation process and ensuring product quality. At the same time, it reduces the consumption of recycled water. 1# qiwu9981
Original poster, is the booster you mentioned the one used in the second evaporation stage? Don’t small-scale plants (with a capacity of 40,000–60,000 tons per year) use any boosters?
By opening the hidden post on the second floor, it turns out that it refers to a two-stage evaporator. The typical pressure parameters for evaporation processes are 3.4 KMA (absolute pressure); this is the vapor pressure at the surface of the molten urine, that is, the water vapor pressure. The condensation (liquefaction) temperature is 26 degrees Celsius. To cause liquefaction, the pressure of the refrigerant must be below 26 degrees Celsius, and it’s difficult for factories to find such a refrigerant. However, it’s easy to increase the condensation (liquefaction) temperature – simply by injecting some steam to raise the pressure. This can be achieved by installing a pressure booster (steam injector) to raise the pressure to 12 KPA, resulting in a condensation (liquefaction) temperature of 49 degrees Celsius. Ordinary circulating water can be used for cooling. During design or operation, the valves should not be opened too wide; the pressure increase should not be too significant, otherwise it will result in both waste of steam and an increased load on the separation process.