Granulation and nozzle
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At present, our company's daily output of urea is about 800 tons, the diameter of the granulation tower is 12 meters, and the effective height is 65 meters. What is currently causing a headache is: The amount of dust is large, there are too many small particles of urea products, and there is a phenomenon of sticking tower when the temperature is high. I wonder if you guys have any advice on whether it can be solved by using a good sprinkler head. Which company's sprinkler head is better? What issues should we pay attention to in process operations? (aqueous solution process)
Give you some suggestions: 1 You can use the patented nozzle from the 11th Institute of the Ministry of Aeronautics and Astronautics instead, and the effect is good. 2 Formaldehyde is added to the evaporation system, and the content can be appropriately controlled to a high point of 0.35%. 3. Add a filter in front of the granulation nozzle pipeline. 4. The air outlet flux at the top of the granulation tower is increased. 5. Control the nozzle speed as low as possible.
Judging from your output, the 12-meter-diameter prilling tower is indeed overloaded. If the particles were larger, the temperature of the particles would be high and they would stick to the tower. From the perspective of dust generation, there are two general directions. The first is mechanical reasons, including nozzle selection, design, manufacturing defects, and impurities blocking the nozzle holes, etc. When the nozzle speed does not match the load, hollow particles and fine dust are likely to appear. The second is chemical reasons. A small amount of urea is chemically decomposed during granulation, and is regenerated into urea, that is, dust during the granulation and cooling process. The vacuum is poor, the free ammonia is heavy, and it is easy to form hollow particles and so on. From the perspective of nozzle design manufacturers, the current patented nozzles from the 11th Institute of the Ministry of Aerospace are relatively better, but it is not absolute. Our factory has to replace a nozzle every year, and they are all from the 11th Institute of the Ministry of Aerospace. The initial effect was very good, but it got worse as time went on. One nozzle was not as good as the other. This post was last edited by lxq700918 on 2009-3-14 11:26 ]