A Review: Recent Progress on Evaluation of Flowability and Floodability of Powder

Abstract

Recent studies evaluating the flowability and floodability of cohesive powder under conditions of consolidation, mechanical force, vibrating force, fluid force, and floodability are reviewed. The ball indentation test is an effective method for evaluating the flowability of a small amount of cohesive powder at very low stress under consolidation conditions. The environmental conditions such as temperature and humidity play an important role in the flow of cohesive powder. With regard to cohesive powder flowing under mechanical force, the FT4 powder rheometer can evaluate the powder flowability using the total energy which is related to the shear stress on the impeller blade. The vibrating capillary method and the vibrating shear tube method are effective for the measurement of the flowability of strongly cohesive powder. The test using powder discharge by air flow can assess the flowability of cohesive powder which Carr's flowability index is an equivalent level by using mass flow rate and interstitial air pressure. Finally, the flushing of cohesive powder occurs when the interstitial air pressure and the void fraction are high. The pressure difference between the interstitial air pressure and the outside of an orifice are the dominant factors in the spouting of powder.

From Quasi-static to Intermediate Regimes in Shear Cell Devices: Theory and Characterisation

“…The full range of available devices to characterise the quasi-static flow of complex cohesive mixtures is described by Ghadiri et al (2020), Ogata (2019), and Schwedes (2003). Here we provided the reader with an overview of the design of classic shear testers, their limitations and their scope for application.…”

“…Although it is key to understand a dense granular flow (Sundaresan, 2001), the characterisation of dynamic properties is still far from the same level of detail. Recent works have summarised the scope of the techniques available today to study the flowability of powders (Ogata, 2019), and the challenges involved in developing reliable dynamic tests for the study of caking and cohesive materials (Ghadiri et al, 2020). They discuss in detail the effects of properties such as size and shape, cohesion and how the interstitial fluid and the applied stress affect the flowability.…”

Studies on Moisture Effects on Powder Flow and Mechanochemical Improvement of Powder Flowability

“…These include variety of existing methods to study ability to flow, different types of powders and their properties, as well as changeable surrounding conditions and different processing and storage parameters. An example of the diverse attitude to powder research may be a recent review on various methods of flowability evaluation, as given by Ogata [5]. Hence, in this Chapter the factors influencing powder flow will be discussed separately in various categories of materials of different properties and economic use, like industrial goods, agricultural products and biomass energy-based resources.…”

Preparation and Properties of Spherical Natural Rubber/Silica Composite Powders via Spray Drying

“…It is well known that particle shape has a strong influence on the flow characteristics of powders (Ogata K., 2019;Talako T. et al, 2009). The morphology of spray dried rubber composite particles was characterized by SEM and the micrographs of the samples are presented in Fig.…”