Issues related to molten urea
Thread Content
This post was last edited by 2005180005 on 2016-11-3 at 11:49. 1. What should be the steam pressure for heating the urea sleeve? The melting point of urea is 132.7℃ ； 2. What are the hazards of urine delivery pipelines? Urine loses ammonia at high temperatures (160°C) to form biuret. Ammonia gas is toxic and flammable; what potential hazards might it pose, such as poisoning and fires? 2. What safety measures should be taken in the design of urine pipelines? Experts with experience in urea production, please provide answers
Answer: 1) For urea heating, it is generally required that the saturation temperature of the steam be above 135°C; saturated steam at a pressure of 0.35MPa to 0.5MPa is usually selected. 2) The urea transport pipelines are high-temperature pipelines, posing risks of corrosion and burns; therefore, it is important to select appropriate piping materials. Additionally, since urea tends to crystallize, necessary heat tracing must be implemented. However, high temperatures and prolonged residence time inside the tube can lead to the formation of biuret. As for the irritant effect of ammonia, it can be felt even with normal breathing; people with ordinary constitutions will not stay in such an environment for long. Of particular concern is the damage that ammonia causes to the eyes – since the eyeballs are composed of 90% water, contact with ammonia results in the formation of ammonia solution along with heat generation, which can burn the eyes and even lead to blindness. 3) The above analysis should be helpful in determining the safety measures for pipeline design; the safety of operators must be taken into account to prevent leaks. However, necessary flushing ports should be provided on the pipelines to prevent blockages caused by low temperatures, so that such blockages can be dealt with promptly once they occur.