METHOD OF GRANULATION OF NITROGENOUS FERTILIZERS AND DEVICE FOR ITS REALIZATION Russian patent published in 2004 - IPC

FIELD: chemical and other industries; production of nitrogenous fertilizers. SUBSTANCE: the invention presents a method of granulation of nitrogenous fertilizers and a device for its realization. The invention is dealt with production of mineral fertilizers, in particular with production of granulated nitrogenous fertilizers. It may be used in chemical and other industries. The method provides for growing of the sizes of the small-sized granules of the production waste (recycle) up to the required size using a multiple sputtering on their surface of a fusion cake of nitrogenous fertilizers on an area section of free fall of the revolved fluidized streams of the recycle at the temperature of 80 with the subsequent return for a repeated granulation. A revolved fluidized stream on an area section of its free fall is divided into two vertical sheet-type curtains along two sides of a longitudinal axis. The sputtering of the fusion cake is made from direction of the outside curtains. In the sputtering process the size of granules of the obtained product is restricted to the greatest allowed size of granules of the marketable products faction. The streams are revolved in directions outside from each other. The device for realization of the method contains a rectangular body, a cooling assembly, a granulation assembly mounted inside the body, the union of introduction of recycle in the granulation assembly, the union of the granulated product unloading from the cooling zone, two manifolds of the fusion cake supply with unions and injectors uniformly located along the length of the manifolds and an assembly of classification. The air intake unions are located in the lower part of the body and the air exhaust unions are located in the upper part of the body. The cooling assembly contains an air distributing lattice, having two zones of holes on each side and one zone of holes in front of it, and a working lattice located above the zones of holes of the air distributing lattice. The granulation assembly with revolving in outside direction two-roll stream of recycle is placed between the side and front sections of the working lattice of the cooling assembly. The granulation assembly in its lower part has an air distributing lattice, a working lattice located above it and made in the form of a launder and the union of the actuating air supply, side walls of which link the working lattice and the air distributing lattices to each other, two slope side guiding walls diverging at an angle of 15-30 deg upward, two deflectors and two side broken slope walls. The guiding walls are spaced so, that to allow the revolved fluidized stream of recycle to pass above the working lattice. The deflectors are made in the form of arcs with a central angle of 30-45 deg and located on the center above the slope side guiding walls. The broken slope walls are located beyond the limits of the side guiding walls and are supplied with the flexible drop aprons, the upper end of which is fixed on the wall and the lower end loosely hangs down under sole weight. The breaking line of the broken walls is at a level of the upper brink of the guiding walls. EFFECT: the invention allows to magnify output of a qualified product of a commercial faction, to exclude additional expenditures on comminution of granules, to increase reliability of operation of the installation. 7 cl, 5 dwg