Overview of drum mixer designs suppressing segregation of bulk mixture

Abstract

The mixing process is used in various areas of production to produce different types of bulk mixtures. These include agricultural mixtures, semi-finished products, bone cements and others. This process is the movement of particles of bulk material components in the space of the working capacity. Mixers of various types are used to set the components of the mixture in motion. One of the most common types of mixers are drum mixers. The main challenge that must be addressed when developing a mixer design is to reduce the segregation that occurs when mixing two or more components of a mixture. Segregation is associated with different particle sizes and densities of the various components. The object of the study is the designs of drum mixers developed in the last decade. All considered designs are divided into three groups, differing in the method of eliminating segregation. The subject of the study is the design features of these mixers. The results of the work were the determination of the most suitable method for eliminating segregation - the use of additional mixing elements in the center of segregation of the mixture, and based on this method, the development of two new designs of drum mixers. The first mixer with sectional radial separators allows you to repeatedly separate the mixture and move the particles of its components relative to each other. This allows you to reduce the degree of segregation of the mixture. The second mixer developed not only extends the residence time of the mixture particles in the drum, but also allows for the creation of crossing and recirculating flows of material. This also helps reduce or prevent segregation.