Storage and Flow of Solids
01 Jan 1964-
About: The article was published on 1964-01-01 and is currently open access. It has received 585 citations till now. The article focuses on the topics: Flow (mathematics).
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62 citations
TL;DR: In this paper, the flow characteristics of 13 cohesive granular materials were studied in the GDR and compared to flow in hoppers of varying angle and discharge diameter at fixed temperature and moisture conditions.
62 citations
TL;DR: In this paper, the evolution of plug flow in three densely packed granular materials in the model of a hopper made of Plexiglas is described using particle image velocimetry (DPIV).
62 citations
TL;DR: In this paper, the influence of interparticle forces on the fluidization behavior of fine group A powders by changing the size distribution of the fine sub-cuts (particles below 45 μ m ) and with increasing temperature was investigated.
61 citations
TL;DR: The assessment of the flowability of powders on the basis of avalanching tests should include both the determination of numerical descriptors of flow such as MTA and scatter, and a determination of the type of motion of the powder bed in order to increase the sensitivity of the method to small changes in powder flow properties.
Abstract: The purposes of this investigation were to develop a method to evaluate flow properties of powders from avalanching tests and to detect similarities and relationships between these data and conventional powder flow properties. The API AeroFlow® automated flowability analyzer was tested using 6 pharmaceutical excipients. Data were presented as mean time to avalanche (MTA), scatter, and a classification based on the type of motion of the powder bed. Powders were also characterized in terms of particle size, particle shape, loss of weight on drying, Carr’s compressibility index, and critical orifice diameter to prevent ratholing. A dual approach, which combines visual observation of the type of motion of the powder bed in the rotating drum with numerical descriptors such as MTA and scatter, was found to be more accurate in the assessment of powder flow than the current practice of using only MTA and scatter values. Statistical analysis established that there are relationships and similarities between the ranking of powder flow properties obtained from the avalanching test and Carr’s compressibility index and the critical orifice diameter. An interaction between particle size and shape, both influencing powder flow, when evaluated with these methods was found. The assessment of the flowability of powders on the basis of avalanching tests should include both the determination of numerical descriptors of flow such as MTA and scatter, and a determination of the type of motion of the powder bed in order to increase the sensitivity of the method to small changes in powder flow properties.
59 citations