Distribution of the components of the building mixture in the presence of secondary raw materials during rotary mixing

Abstract

The purpose of this study is a stochastic description of the distribution of solid dispersed components, including those from secondary raw materials, according to the characteristic angle of scattering ϴij when receiving a construction mixture at the first stage of operation of the rotary apparatus. Two stages of the formation of rarefied flows are assumed: when scattering particles of components by elastic blades of a rotating drum and when interacting with the baffle surface. Modeling method this is energy method of Klimontovich Yu.L. The analysis of the efficiency of the first stage (rotary mixing) is carried out based on the obtained distribution functions of the number of particles of bulk components over the scattering angle, taking into account their physical and mechanical properties and a variety of design and operating parameters of the apparatus. The bulk of the particles of the mixed components are scattered at the initial angles of rotation of the mixing drum, when the deformation of the elastic blades is most significant. This is accompanied by the characteristic first bursts of the obtained distribution curves (ϴij< 0.1 rad) for the number of particles of the tested bulk materials at the given ranges of parameters.

Stochastic analysis of impact mixing of bulk materials in a rotary apparatus

“…The successful implementation of one of the promising stages in the processing of granular and/or powder materials, such as mixing these components in rarefied flows, is observed in impact-type devices. For example, the creation of these rarefied flows is ensured when the mixing elements operate in the form of radial brushes, beats with a helical winding in one [14] or two directions [13,[15][16][17], elastic blades [9,10] on a rotating drum. Thus, in the projected continuous-action rotary apparatus [9], as noted earlier, there is a division of the mixing process into two appropriate stages: (1) obtaining rarefied flows of granular and/or powder components by scattering their particles with elastic blades [10]; (2) impact mixing of components when interacting with the bump surface (Fig.…”

“…With the help of this conveyor, first, the layers of mixed materials are delivered, vertically loaded into the working area of the apparatus, into the gap with the mixing drum. After interacting with its elastic blades (stage 1 [10], mixing), the particles of bulk materials ( 1, 2 i = ) in the created rarefied flows, hitting the inclined bumper 2, return to the moving belt, forming a mixture (stage 2, mixing, (Fig. 1).…”

“…The process of mixing bulk materials at stage 1 received a stochastic description in work [10] when setting the parameters:…”

“…The purpose of this work is to analyze the distribution of bulk materials according to the characteristic parameters of the mixing process at the second stage of processing in a rotary apparatus [9]. At this stage of mixing, there is an impact interaction with the bump surface of rarefied flows of granular components obtained by scattering the elastic blades of a rotating drum at the previous stage of the technological chain [10]. Interest in the design of new devices for this purpose is explained by the specific properties of the processed working materials and the specific conditions of the technology for obtaining the finished product in the form of their high-quality mixture [11].…”

“…First, it is required to identify the most significant factors influencing the performance of the investigated technological operation while weakening the effects of segregation and agglomeration, the adhesive properties of working materials [29,31]. In particular, the appropriate selection is made from the selected parameters of the design of the rotary mixer [9] and the characteristics for the modes of its operation both at the first [10] and at the second stages of this process. Secondly, it is necessary to establish the effective ranges of variation of the parameters identified by the specified criterion.…”