How to deal with urea sticking at the bottom of the granulation tower?
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The granulation tower used in urea production during the summer is a challenge; in the granulation towers we are currently using, tremors in the material-scraping mechanism occur intermittently after just over a month of cleaning, which results in small lumps of urea in the finished product. If cleaning is not carried out promptly, defective products will be produced. If it is not cleaned and kept running, it will affect the safe and stable operation of the scraper. What methods do people use for cleaning? It’s unsafe for people to go in and clean it; we don’t allow anyone to enter for cleaning purposes. At the moment, we can only use condensate for rinsing and recovery. How does everyone handle this? Please share your methods!
This post was last edited by WJHSWSW on 2017-8-11 06:39. The manager has ordered that people go in to clean up the parking area; can’t you avoid doing that? You’ll be assessed soon. “Is “Safety first, production second” just a slogan that LDs use for show?
Rinse with condensate at around 80°C to obtain urine of a certain concentration, and then add it to the system for evaporation and granulation! It’s clean, quick, and safe as well.
Control the production load, adjust the nozzle speed to ensure maximum utilization of the granulation tower’s cross-sectional area, and enhance the screening of the finished product.
Wow, the collection chamber under the tall tower is so big!
Perform regular cleaning; it used to be done once a month, during periods of high load. As for the control of process parameters, it has been mentioned already. Is the load too high? Is the evaporation load stable? Is the moisture level up to standard?
We here enforce strict safety protocols, and that’s why cleaning is not allowed inside; even if the vehicle is parked, cleaning is not permitted!
The load is not high; in the operation of the 24-meter granulation tower, the amount of particles produced per day is around 1,300 tons. When producing smaller particles, this figure rises to about 2,650 tons per day. At present, due to the high temperatures, the temperature of the circulating water is high, the vacuum level is slightly lower, and the moisture content is higher by 0.5–0.6%
It’s likely that the load is too high, resulting in insufficient cooling effect in the granulation tower. Also, could the local water vapor concentration be too high? Controlling compliance is key!
Is it vibrating? Is something scraping the ground? Is the nozzle leaking, or is water getting into the granulation tower?
First, to increase the distance between the scraper of the material scraper machine and the floor of the granulation tower, we control it at around 50 mm； Secondly, in this way, with a greater distance between the scraper and the bottom of the tower, even if the scraper touches the ground and the scraper arm vibrates, it will not lift up the urea on the ground, so no fragments will be generated ； Third, based on the experience of a factory in the south, changing the scraper blade of the material scraper from a straight shape to a serrated one can prevent urea accumulated at the bottom of the tower from hardening and caking. Fourth, the urea lumps on the ground should be removed regularly during the annual maintenance.