Patent ID: 7838080

Claim:
A method for producing urea pellets with a sphericity >75% and a defined residual moisture content ≦0.5%, in a spouted bed apparatus, comprising: inserting a urea containing liquid with a temperature ranging from ambient temperature to above a melting temperature into a solid matter flow of the spouted bed apparatus and maintaining a solid gas material flow by a gas flow inserted from a bottom thereof, feeding the gas flow almost horizontally to the processing chamber of the spouted bed apparatus and deflecting the gas flow in the processing chamber, laterally feeding a material particle flow from an almost circular gas-material flow embodied in the processing chamber to gas jets in an entry area of the processing chamber, increasing a flow speed of the gas-material flow between the entry area of the gas flow in the processing chamber and a spray zone by adjustable guiding metal sheets or adjustable gap openings such that by a suction effect of the gas nozzles more material particles are entrained from the almost circular gas-material flow and thus the flow of high particle loads is adjusted in a controllable manner, and spraying a urea containing fluid into an area of high particle loads of the spray zone onto surfaces of particles of the material and dehydrated and granulated in the gas flow at temperatures up to maximally below a melting temperature of pure urea under at least one of uncontrolled or controlled heat or material transfer with a simultaneous separation, wherein the almost circular gas-material flow is adjusted by at least one fixed or adjustable gap opening or at least one fixed or adjustable guiding metal sheet, with at least one deflecting part that is adjustable, each being provided in an area of the gap-shaped opening(s) at a central area located inside the arrangement ensuring a curved guidance of the processing gas from the inlet area almost vertically to and in z direction of a longitudinal plane of the spouted bed apparatus through at least one gap opening and into the outlet area approximately parallel in reference to the longitudinal plane.