Experimental Study of the Stage of Formation of Sparse Flows of Bulk Components by the Rotary Method
摘要
The urgent problem of reducing the influence of the segregation effect on the homogeneity of the final product when mixing solid dispersed materials must be addressed, in particular in such industries as powder metallurgy, pharmaceuticals, and glass production. Segregation significantly affects the physical and chemical properties of multicomponent systems. The main objective of the work is to study the mechanisms of rarefied flow formation at the initial stage of mixing by a vane atomizer with elastic plates to prevent segregation. Data are obtained on the distribution of particles of individual solid dispersed components by levels (shelves) of a vertical trap under different operating modes of the rotary unit. The pilot plant is a model rotary unit with a vane atomizer; its design features are a curvilinear guide device for preliminary mixing, elastic elements in the form of narrow plates for converting components into dispersed flows, and a corrugated baffle for setting different directions of particle movement. The plates are made of polyethylene terephthalate glycol-modified plastic and are fixed on the drum-cylinder along the tangent planes. At this stage of the experimental tests, the distribution of the component particles is studied before interaction with the corrugated baffle plate, then the operating mode of the model installation is set by selecting the values of the drum rotation frequency and the parameter for adjusting the position of the curvilinear guide device, taking into account the physical properties of the mixed materials and their granulometric composition. It is found that at a drum rotation frequency of 400 min–1, the control indicator (the maximum value of the proportion of component particles from their total number when settling on one shelf of the vertical trap) for natural sand is exceeded by 1.27 times compared to the data for soda ash.