METHOD OF GRANULATION OF MINERAL FERTILIZERS Russian patent published in 2017 - IPC B01J2/04 

FIELD: agriculture.

SUBSTANCE: invention relates to the method of granulation of mineral fertilizers from melt, including fragmenting the melt into drops, crystallizing the drops during their free fall in a counter current of cooling air in a granulation tower, which is removed from the crystallization zone, feeding it into the wash column for the stage of purification and cooling by irrigation with cooling washing fluid in a counter flow with compressing it due to cocurrent air flow and torch flow, and returning the cooled and throughput air to the lower part of the crystallization zone of the granulation tower under pressure created by the cocurrent flow of the falling drops of the cooled washing fluid, required to overcome the resistance arising in the granulation tower during the falling of the melt drops, and characterized in that the irrigation density of the washing fluid is carried out depending on the required air pressure by the ratio: , where: q is the mean value of the irrigation density of the washing fluid in the air cleaning and cooling zone, ; ΔP - air pressure, ; ρ_w, ρ_a - the density of air and washing liquid, respectively, ; H, h - the length of the air cleaning, cooling, compression zone and its current size, respectively, m; r_s is the radius of the washing solution drops, m; ƒ(r_s) - the density distribution of drops along the radius, ; , ω^s - the speeds of the drops soaring flow and the counter air flow in the compressing tower, respectively, ; ξ- the drag coefficient of the washing fluid drops; d - sign of the differential; and the ratio of rates of the washing cooling solution and the melt to be granulated, depending on the conditions of the dispersion of the flows and the dimensions of the granulation tower and the washing column, is determined by the ratio: , where: G_w, G_s - rates of the melt and the compressing washing agent, respectively, ; d_w, d_s are the drop sizes of the melt and the washing fluid, mm; , - the soaring speeds of the drops of the melt and the counter air flow, respectively, in the granulation tower, ; S_t, S_c are the cross-sectional areas of the tower and the washing column, respectively, m²; h_t, h_c are the tower height and the column height, respectively, m.

EFFECT: invention allows to reduce power consumption and to exclude humidifying hygroscopic granules by water vapours formed above the washing fluid solution.

3 cl, 2 dwg