scholarly journals Powder flow criteria for design of vertical silo walls

2013 ◽  
Vol 33 (3) ◽  
pp. 453-462 ◽  
Author(s):  
José P. Lopes Neto ◽  
José W. B. do Nascimento ◽  
Rafael C. Silva ◽  
Carlos A. da Costa
Keyword(s):  
Mass Flow ◽  
Reduced Model ◽  
Powder Flow ◽  
Flow Properties ◽  
Bulk Solids ◽  
Flow Prediction

For design of vertical silos walls involving the storage of bulk solids to be safe and reliable, it is important knowing the largest possible number of variables such as: flow properties, silo geometry and pattern of flow desired. In order to validate the theories of flow prediction and design of conical hoppers, the flow properties of two bulk solids were determined, the theories of Jenike's flowability and Enstad and Walker for hopper design were analyzed and the results were compared with those experimentally obtained in a reduced model of a semicircular-section silo. Results show that Enstad theory for the hopper design is adequate to occur mass flow inside the silo, and for the sizing of the discharge outlet, the Walker's theory was closer to the appropriate than Jenike's theory, which was higher around 100% than the experimental hopper outlet.

Effects of powder flow properties on capsule filling weight uniformity

2013 ◽  
Vol 39 (9) ◽  
pp. 1464-1475 ◽  
Author(s):  
Juan G. Osorio ◽  
Fernando J. Muzzio
Keyword(s):  
Powder Flow ◽  
Flow Properties

Effect of surface compositional difference on powder flow properties

2019 ◽  
Vol 344 ◽  
pp. 363-372 ◽  
Author(s):  
Camila G. Jange ◽  
R.P. Kingsly Ambrose
Keyword(s):  
Powder Flow ◽  
Flow Properties ◽  
Compositional Difference ◽  
Effect Of Surface

Investigation of the extent of surface coating via mechanofusion with varying additive levels and the influences on bulk powder flow properties

2011 ◽  
Vol 413 (1-2) ◽  
pp. 36-43 ◽  
Author(s):  
Qi (Tony) Zhou ◽  
Li Qu ◽  
Thomas Gengenbach ◽  
John A. Denman ◽  
Ian Larson ◽  
...  
Keyword(s):  
Surface Coating ◽  
Powder Flow ◽  
Flow Properties ◽  
Bulk Powder

scholarly journals Contrasting the crospovidones functionality as excipients for direct compression

2015 ◽  
Vol 51 (1) ◽  
pp. 155-171 ◽  
Author(s):  
Daniel García Ramírez ◽  
Leopoldo Villafuerte Robles
Keyword(s):  
Drug Product ◽  
Absolute Number ◽  
Powder Flow ◽  
Direct Compression ◽  
Flow Properties ◽  
Technological Performance ◽  
A Value ◽  
Tablet Disintegration ◽  
Input Variables ◽  
Model Drug

Specific values of technological properties of excipients allow the establishment of numerical parameters to define and compare their functionality. This study investigates the functionality of Polyplasdones XL and XL10. Parameters studied included tablet disintegration profiles, compactibility profiles and powder flow. The results allowed the establishment of quantitative surrogate functionalities of technological performance, such as absolute number, and as a value relative to the known microcrystalline cellulose type 102. Moreover, the establishment of an explicit functionality to improve the technological performance of two diluents and a model drug was investigated, as was setting up of these functionalities, as quantitative values, to determine the input variables of each material and its probable functionality in a drug product. Disintegration times of pure Polyplasdone XL and its admixtures were around half that of Polyplasdone XL10. The improvement in tablet compactibility was 25-50% greater for Polyplasdone XL10 than Polyplasdone XL. Crospovidones proportions of up to 10% have little effect on the flow properties of other powders, although pure Polyplasdone XL10 and its admixtures display compressibility indexes about 20% greater than Polyplasdone XL. The observed results are in line with a smaller particle size of Polyplasdone XL10 compared to Polyplasdone XL.

Discrete Phase Modeling of the Powder Flow Dynamics and the Catchment Efficiency in Laser Directed Energy Deposition with Inclined Coaxial Nozzles

2021 ◽  
pp. 1-37
Author(s):  
Sachin Alya ◽  
Ramesh Singh
Keyword(s):  
Mass Flow ◽  
Energy Deposition ◽  
Flow Dynamics ◽  
Free Form ◽  
Powder Flow ◽  
Process Conditions ◽  
Directed Energy Deposition ◽  
Discrete Phase ◽  
Directed Energy ◽  
Inclined Nozzle

Abstract Laser Directed Energy Deposition (DED) is one of the most promising additive manufacturing processes for restoring high value components. The damaged components can have complex free-form shapes which necessitates depositions with an inclined nozzle, where, the gravity can adversely affect the powder flow dynamics and the powder catchment efficiency (PCE). PCE is defined as the fraction of the total mass flow rate entering the melt pool and a low PCE can render the process inviable. In this paper, the effect of nozzle inclination on the powder flow dynamics and resulting PCEs have been studied. It was found that the powder flow dynamics is altered significantly in an inclined nozzle and results in an asymmetric and skewed powder jet. This affects the powder focusing adversely and the PCE deteriorates rapidly with an increase in the inclination and falls below 20% at 75°. A discrete phase model has been developed to understand the powder flow dynamics at different inclinations and process conditions. The mass flow distribution asymmetry on the focal plane at various nozzle inclinations have been analyzed via the model. The model is able to predict PCEs at different nozzle inclinations with reasonable accuracy. It has been observed that carrier gas flow, particle size and laser diameter affect the PCE significantly and can be used to counter the enhanced powder loss at large nozzle inclinations. Process maps have been developed to identify the favorable, acceptable and low PCE regions for the selection of optimal DED parameters.

scholarly journals Correlation between Powder Flow Properties Measured by Shear Testing and Hausner Ratio

2015 ◽  
Vol 102 ◽  
pp. 218-225 ◽  
Author(s):  
Horng Yuan Saw ◽  
Clive E. Davies ◽  
Anthony H.J. Paterson ◽  
Jim R. Jones
Keyword(s):  
Powder Flow ◽  
Flow Properties ◽  
Shear Testing ◽  
Hausner Ratio

Mass Flow and Thrust Performance of Nozzles With Mixed and Unmixed Nonuniform Flow

1995 ◽  
Vol 117 (4) ◽  
pp. 617-622 ◽  
Author(s):  
Reiner Decher
Keyword(s):  
Mass Flow ◽  
Total Pressure ◽  
Nonuniform Flow ◽  
Flow Properties ◽  
One Dimensional ◽  
Flow Equations ◽  
Design Variables ◽  
Analytic Expressions ◽  
The One ◽  
Thrust Performance

The calculated thrust and mass flow rate of a nozzle depend on the uniformity of the entering flow. The one-dimensional flow equations are extended to arrive at analytic expressions for the predicted performance of a nozzle processing two streams whose properties are determined ahead of the throat. The analysis approach forms the basis for the understanding of flows which have more complex distributions of total pressure and temperature. The uncertainty associated with mixing is examined by the consideration of the two limiting cases: compound flow with no mixing and completely mixed flow. Nozzle discharge and velocity coefficients accounting for non-uniformity are derived. The methodology can be extended to experimentally measured variations of flow properties so that proper geometric design variables may be obtained.

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