Many times prills and granules suffer quality problems like low strength figures, dust and caking behaviour. These quality problems are due, in large part, to high moisture content. The moisture content of the final product is largely determined by the moisture content in the urea melt feed and thus the design, operation and maintenance of the evaporation (also called concentration) section is critical. This paper will discuss, in detail, ways in which one is able to control and minimize the moisture content in prills and granules.
This paper was presented during the Nitrogen & Syngas Conference in February 2014 in Paris.