Patent ID: 8945271
Filing Date: 2015-02-03
Classification: C05C

Abstract:
1. A method for producing urea granules having a low moisture absorption capacity, with a urea granulator having a granule flow inlet side and oppositely a granule flow outlet side, forming an axis between the inlet side and outlet side, comprising: a) spraying a urea solution and a urea/ammonium salt-stream, as a mixture or separately, via a feed system comprising a plurality of nozzles spaced along the axis into the urea granulator onto seed particles, b) adjusting the relative proportions of the urea solution and urea/ammonium salt-stream such that the highest amount of the urea/ammonium salt-stream is sprayed into the urea granulator at the granule flow inlet side and the amount of the urea/ammonium salt-stream is decreased along the axis of the urea granulator from the granule flow inlet side to the granule flow outlet side, and the highest amount of the urea solution is sprayed into the urea granulator proximate the granule flow outlet side and the amount of the urea solution is decreased alongside the axis of the urea granulator from the granule flow outlet side to the granule flow inlet side wherein the urea/ammonia salt-stream comprises a urea:ammonium salt ratio between 4 and 20, a water content of 0-10% by weight and optionally up to 5% by weight of additives.