| 摘要 |
<p>The emission of fumes is suppressed from a prilling tower for producing prills of ammonium nitrate or urea by conducting particles from a spray of a melt of the material countercurrent through a stream of air. The spray of the material, as it leaves the prilling head is passed through a stagnant atmosphere of ammonia. In addition, the particles of the spray are coated with ammonia and their cooling by the countercurrent air stream is accelerated. To produce the ammonia atmosphere, a shroud (29) is provided about the spray nozzle or nozzles (21) into which gaseous ammonia is injected.</p> |
