Patent EA-001126-B1 (EA)
Title: Method and granulator for granulation
Inventor: HONDA TETSURO
IPC: C05G5/00
Filed: 1998-09-03
Abstract: 1. An improved granulation method, wherein use is made of a granulator having a bottom floor of a granulation section whose bottom is a perforated plate, an upper air feed pipe for feeding air for fluidization to the said bottom floor of the said granulation section, a lower air feed pipe, air feed pipes branched from the said lower air feed pipe for jetting air into the said granulation section, and jetting nozzles provided at the centers of the said air outlets for jetting a molten raw material; which comprises jetting a molten raw material from the said jetting nozzles to approximately spherical nuclei in the granulation section, which have been fed after the particles  2. An improved granulation method, wherein use is made of a granulator having a bottom floor of a granulation section whose bottom is a perforated plate, an air feed pipe for feeding air for fluidization to the bottom floor of the granulation section, and jetting nozzles provided in the bottom floor for jetting a molten raw material by using highly pressurized air as an auxiliary gas; which comprises jet-ting a molten raw material from the said jetting nozzles to approximately spherical nuclei in the granulation section, which have been fed after the particles (of nuclei) diameter of which has been caused to be an average of 0.4 to 3.0 mm, to form granules. 3. An improved granulation method, wherein use is made of a granulator having a bottom floor of a granulation section whose bottom is a perforated plate, an upper air feed pipe for feeding air for fluidization to the said bottom floor of the said granulation section, a lower air feed pipe, air feed pipes branched from the said lower air feed pipe for jetting air into the said granulation section, jetting nozzles provided at the centers of the said air outlets for jetting a molten raw material, and one or more partition walls provided on the said floor bottom, for partitioning the said air feed pipes, so that the partition walls may form a passage in which nuclei may be moved continuously from the inlet of the granulator toward the outlet of the granulator; which comprises jetting a molten raw material from the said jetting nozzles to the said nuclei that are approximately spherical nuclei in the granulation section, which have been fed after the particles (of nuclei) diameter of which has been caused to be an average of 0.4 to 3.0 mm, to form granules. 4. An improved granulation method, wherein use is made of a granulator having a bottom floor of a granulation section whose bottom is a perforated plate, an air feed pipe for feeding air for fluidization to the bottom floor of the granulation section, jetting nozzles provided in the bottom floor for jetting a molten raw material by using highly pressurized air as an auxiliary gas, and one or more partition walls provided on the said bottom floor, for partitioning the said nozzles, so that the partition walls may form a passage in which nuclei may be moved continuously from the inlet of the granulator toward the outlet of the granulator; which comprises jetting a molten raw material from the said jetting nozzles to the said nuclei that are approximately spherical nuclei in the granulation section, which have been fed after the particles (of nuclei) diameter of which has been caused to be an average of 0.4 to 3.0 mm, to form granules. 5. The improved granulation method as claimed in claim 1, 2, 3, or 4, wherein the molten raw material is sprayed through a shower-type spray with a curvature having a spherical plate with a number of holes opened, the said sprayed molten urea is cooled and solidified, and the cooled solidified approximately spherical nuclei, having an average particle diameter of 0.4 to 2.0 mm, are fed. 6. The improved granulation method as claimed in claim 1, 2, 3, or 4, wherein the molten raw material is sprayed through an oscillated shower-type spray, the said sprayed molten urea is cooled and solidified, and the cooled solidified approximately spherical nuclei, having an average particle diameter of 0.4 to 2.0 mm, are fed. 7. The improved granulation method as claimed in claim 1, 2, 3, or 4, further comprising recycling to the granulator granules having smaller particle diameters out of the granules of the product, to make the particle diameter distribution of the product acute. 8. The improved granulation method as claimed in any one of claims 1 to 7, wherein the said molten raw material liquid is any one of molten urea, molten urea in the form of a slurry containing solid another component in molten urea, and molten sulfur. 9. The improved granulation method as claimed in any one of claims 1 to 7, wherein, as the said molten raw material, molten urea is fed to the former section nozzles of the said granulator, and molten sulfur is fed to the latter section nozzles of the said granulator. 10. An improved granulator, which is a granulator in claim 1 having a bottom floor of a granulation section whose bottom is a perforated plate, an upper air feed pipe for feeding air for fluidization to the said bottom floor of the said granulation section, a lower air feed pipe, air feed pipes branched from the said lower air feed pipe for jetting air into said granulation section, and jetting nozzles provided at the centers of the said air outlets for jetting a molten raw material liquid, to form granules by jetting a molten raw material from the said jetting nozzles to nuclei fed in the granulation section, which nuclei have been caused to have a prescribed particle diameter, wherein the direction of the flow of air passing through the holes made in the perforated plate has a slant angle with the direction of the flow of granules with respect to the vertical axis. 11. An improved granulator, which is a granulator in claim 3 having a bottom floor of a granulation section whose bottom is a perforated plate, an upper air feed pipe for feeding air for  fluidization to the said bottom floor ofxthe said granulation section, a lower air feed pipe, air feed pipes branched from the said lower air feed pipe for jetting air into the said granulation section, jetting nozzles provided at the centers of the said air outlets for jetting a molten raw material, and partition wails provided on the said bottom floor, for partitioning the said air feed pipes, so that the partition walls may form a passage in which nuclei may be moved continuously from the inlet of the granulator toward the outlet of the granulator, to form granules by jetting a molten raw material from the said jetting nozzles to the said nuclei fed in the granulation section, which nuclei have been caused to have a prescribed particle diameter, wherein the direction of the flow of air passing through the holes made in the perforated plate has a slant angle with the direction of the flow of granules with respect to the vertical axis. 12. An improved granulator, which is a granulator in claim 2 having a bottom floor of a granulation section whose bottom is a perforated plate, an air feed pipe for feeding air for fluidization to the bottom floor of the granulation section, and jetting nozzles provided in. the bottom floor for jetting a molten raw material liquid by using highly pressurized air as an auxiliary gas, to form granules by jetting a molten raw material from the said jetting nozzles to nuclei fed in the granulation section, which nuclei have been caused to have a prescribed particle diameter, wherein the direction of the flow of air passing through the holes made in the perforated plate has a slant angle with the direction of the flow of granules with respect to the vertical axis. 13. An improved granulator, which is a granulator in claim 4 having a bottom floor of a granulation section whose bottom is a perforated plate, an air feed pipe for feeding air for fluidization to the bottom floor of the granulation section, jetting nozzles provided in the bottom floor for jetting a molten raw material by using highly pressurized air as an auxiliary gas, and partition walls provided on the said bottom floor, for partitioning the said nozzles, so that the partition walls may form a passage in which nuclei may be moved continuously from the inlet of the granulator toward the outlet of the granulator, to form granules by jetting a molten raw material from the said jetting nozzles to the said nuclei fed in the granulation section, which nuclei have been caused to have a prescribed particle diameter, wherein the direction of the flow of air passing through the holes made in the perforated plate has a slant angle with the direction of the flow of granules with respect to the vertical axis. 14. A granulator, which is a granulator to be used in claim 3 or 4, wherein one or more partition walls are provided on the bottom floor, with the partition walls parallel to the walls of the granuiator, so that the partition walls may form a passage in which nuclei may be moved continuously from the inlet of the granulator toward the outlet of the granulator, and that the said partition walls are staggered, so that at least one of the partition walls extends from one side section of the granulator toward the other opposite side section of the granulator, and the other partition wall extends from the said other opposite side section of the granulator toward the said one side section of the granulator. 15. The improved granulator as claimed in any one of claims 10 to 14, wherein the granulator has such a specified elongate configuration that the ratio L/M is 2 or more but 40 or less, in which L is the length of the bottom section of the granulator in the direction of the flow of granules, and M is the width of the flow of granules. 16. The improved granulator as claimed in any one of claims 10 to 15, wherein the granulator has integrally a function for feeding, as nuclei, approximately spherical nuclei having an average particle diameter of 0.4 to 1.0 mm, to the granulator. 17. The improved granulator as clai