Research of plate granulator operation modes in the production of coarse carbamide granules

The object of research is granulation of mineral fertilizers by the rolling method. One of the most problematic places is the uncertainty of the conditions of the temperature regime of granulation. The paper considers the technology for obtaining enlarged urea granules of prolonged action. It is indicated that an increase in the diameter of the granules to 7–10 mm increases the efficiency of the use of mineral fertilizers by the consumer. It is proposed to obtain large carbamide granules by rolling in a plate granulator. It is indicated that the setting of the optimal operating parameters of the tray granulator is an important factor in the efficient operation of the equipment. A scheme of a pilot plant for granulating mineral fertilizers is presented, a methodology for conducting experimental studies and design parameters of a plate granulator are described. It is indicated that in the process of experimental studies, the design parameters changed: the tilt angle of the plate, the height of the side and the frequency of rotation of the plate, the angle of opening of the spray jet by the hydraulic nozzle. In the process of research, the influence of regime and technological parameters, namely, the temperature of the layer on the plate is studied. As a result of experimental studies, the optimal ranges of design and regime-technological parameters for obtaining enlarged carbamide granules in a plate granulator were revealed. The influence of the location of the nozzle for spraying the melt on the layer relative to the plane of the plate is shown, which results in the particle size distribution of the granular product. It is indicated that a higher content of the commercial fraction in the finished product is observed when the layer in the left sector of the upper part of the plate is irrigated by the rising melt. A technique for determining the static strength of the obtained carbamide granules is given. A calculation equation for determining the static strength of a granule is presented. A diagram of a laboratory device for determining the static strength of granules is presented, which made it possible to determine the values of the static strength of granules for individual fractions, namely: for coarse, fine and commercial fractions. It is shown that the obtained values correlate well with standardized indicators.