摘要:
To effectively prepare granular urea that constantly has a moisture concentration of 0.3 wt % or less in the product and has a large grain load strength to be hardly crashed. In a granulating process for preparing granular urea from an aqueous urea solution using a fluidized bed method or a fluidized, spouted bed method, an aqueous urea solution having an urea concentration of 94-98.5 wt % is used, and an operation temperature of the fluidized bed is controlled in a range of 110-120° C. to accelerate drying of a granulated product, thereby giving a granular urea product having moisture of 0.3 wt % or less in the product.
摘要:
There is disclosed a process to produce fertilizer granules containing urea and ammonium sulfate with a high ammonium sulfate concentration of ≦60 wt. % in a fluidized bed granulator, which process comprises the steps of: a) a molten urea suspension consisting of ammonium sulfate having an average particle size of 30 to 300 &mgr;m and urea having a temperature range of 120 to 155° C. is produced, b) the molten urea suspension produced at the stage a) is then injected from below on the fine particles of urea/ammonium sulfate in a fluidized bed granulator by means of at least a nozzle, while the fluidized bed is loosened by a spouting air flow in the injection area, and subsequently, c) the fertilizer granules generated in the fluidized bed are separated and, if necessary, treated. Homogeneous urea/ammonium sulfate granules of an ammonium sulfate content between 30 and 60 wt. % can be produced this way without any problems, while the particle size of granules can be adjusted selectively and dust emissions by granulation can be reduced to a minimum.
摘要:
The present invention provides a granulation method with increased drying effect while assuring the pressure for spraying the aqueous solution and the necessary number of nozzles equivalent to those of conventional design. Specifically, the granulation method uses a granulator structured by a fluid bed which fluidizes the granulating-particles, an air feed pipe to introduce air, a nozzle for spraying the raw material aqueous solution being located at center part of the air feed pipe, and a perforated plate to feed a fluidization air to the fluid bed, thus granulating the raw material aqueous solution by spraying thereof from the nozzle into a granulation part, wherein a multi-nozzle in a specified shape having a plurality of nozzle ends thereon is used as the nozzle for spraying the raw material aqueous solution.
摘要:
In a granulating process for preparing granular urea from an aqueous urea solution using a fluidized bed method or a fluidized, spouted bed method, an aqueous urea solution having a urea concentration of 94-98.5 wt % is used and the operational temperature of the fluidized bed is controlled in a range of 110-120° C. to accelerate the drying of a granulated product to thereby give a granular urea product having a moisture content of 0.3 wt % or less.
摘要:
The present invention provides a granulation method with increased drying effect while assuring the pressure for spraying the aqueous solution and the necessary number of nozzles equivalent to those of conventional design. Specifically, the granulation method uses a granulator structured by a fluid bed which fluidizes the granulating-particles, an air feed pipe to introduce air, a nozzle for spraying the raw material aqueous solution being located at center part of the air feed pipe, and a perforated plate to feed a fluidization air to the fluid bed, thus granulating the raw material aqueous solution by spraying thereof from the nozzle into a granulation part, wherein a multi-nozzle in a specified shape having a plurality of nozzle ends thereon is used as the nozzle for spraying the raw material aqueous solution.