ANALYSIS OF THE METHODS OF OBTAINING GRAINS AND MEANS FOR THEIR IMPLEMENTATION

Abstract

Тhe article discusses the main methods of obtaining granules from various powdered materials. An analysis of the equipment for the production of granules was carried out and their classification scheme was presented. The main directions of development and improvement of equipment for granulation of powdery materials have been determined.
Granulated materials are widely used in many industries (building materials, chemical, metallurgical, food, etc.), as well as in agriculture. In connection with such diverse use of these materials, and in accordance with the requirements for particle size composition, strength, thermal conductivity, moisture consumption, etc., a large number of methods and equipment for their production have been developed. Depending on the granulation mechanism, the main granulation methods and technical means for their implementation can be distinguished.
Numerous experimental studies of granulation processes in mixing devices - granulators and in drum machines have shown that the final size of granules is determined by many parameters, among which it is important to note the size of the nucleus-germ formed, the size of powder particles and drops of binder substances, agglomeration conditions, powder and liquid properties and granulation methods. In works, the influence of particle sizes of drops of binder on the formation and subsequent growth of granules and on the morphology of the structure is considered. It should be noted that predicting the appropriate amount of liquid (droplet size) to obtain the desired granule size is very difficult due to the fact that, in addition to the factors mentioned above, the sizes of the granules formed depend on the adhesive properties of the powder and on the physical properties of the liquid (viscosity, surface tension). The thickness of the layering and the conditions of completeness of the granule structure are determined by the moisture content or wettability of the surface.