Abstract: A fluidized bed cooler for cooling a urea-containing granular material may include a cooler chamber having a product inlet opening, a product outlet opening, a perforated plate disposed in the cooler chamber, and at least one cooling medium entry opening disposed beneath the perforated plate. The product inlet opening may be disposed above the perforated plate, and a baffle plate may be disposed between the product inlet opening and the perforated plate. A distributor plate may be disposed between the baffle plate and the perforated plate. An area of the distributor plate may be 10% to 50% greater than an area of the baffle plate.

Abstract: A fluid-bed granulator system with adjustable cooling includes a fluid-bed granulator. A first cooler is externally connected to the fluid-bed granulator or forms an internal part of the fluid-bed granulator. A product screen is connected to the first cooler and the fluid-bed granulator. The product screen includes an exit for final on-size product particles, an exit for oversized particles, and an exit for undersized particles. The exit for the undersized particles is connected to the fluid-bed granulator and the exit for the oversized particles is connected to the fluid-bed granulator via one or more crushers. A recycle cooler is located and connected between the fluid-bed granulator and the exit for undersized particles and/or the recycle cooler is located between the fluid-bed granulator and the exit for the oversized particles. The recycle cooler is connected to the fluid-bed granulator via one or more recycle inlets.

Abstract: A fluidized bed cooler for cooling a urea-containing granular material may include a cooler chamber having a product inlet opening, a product outlet opening, a perforated plate disposed in the cooler chamber, and at least one cooling medium entry opening disposed beneath the perforated plate. The product inlet opening may be disposed above the perforated plate, and a baffle plate may be disposed between the product inlet opening and the perforated plate. A distributor plate may be disposed between the baffle plate and the perforated plate. An area of the distributor plate may be 10% to 50% greater than an area of the baffle plate.

Abstract: A process for purifying exhaust air from a granulation plant for producing a urea-containing granulate includes contacting a gas stream containing a urea-containing dust and ammonia with a sulfuric acid solution or a nitric acid solution in a scrubbing process. The scrubbing process involves scrubbing the gas stream with a first weakly acidic scrubbing solution in a first scrubbing stage and scrubbing the gas stream exiting the first scrubbing stage with a second scrubbing solution having a lower pH than the first weakly acidic scrubbing solution in a second scrubbing stage. The acidic scrubbing solution generated in the second scrubbing stage may be recycled into the first scrubbing stage via a conduit and used therein as the first weakly acidic scrubbing solution. A pre-scrubbing stage for scrubbing dust out of the gas stream may additionally be arranged upstream of the first scrubbing stage.

Abstract: A process for purifying exhaust air from a granulation plant for producing a urea-containing granulate may involve causing a gas stream containing a urea-containing dust and ammonia to contact a sulfuric acid solution or a nitric acid solution in a scrubbing process. The scrubbing process may comprise scrubbing the gas stream with a first weakly acidic scrubbing solution in a first scrubbing stage and then scrubbing the gas stream exiting the first scrubbing stage with a second scrubbing solution having a lower pH than the first weakly acidic scrubbing solution in a second scrubbing stage. The acidic scrubbing solution generated in the second scrubbing stage may be recycled into the first scrubbing stage via a conduit and used therein as the first weakly acidic scrubbing solution. A pre-scrubbing stage where dust is scrubbed out of the gas stream may additionally be arranged upstream of the first scrubbing stage.