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Phone Con Minutes

08/09/2010 16:00-17:15

WP1 – Kickoff

Participants:

BASF: Herman Feise (left earlier), Thomas Letzelter

TU BS: Harald Zetzener, Arno Kwade (later)

UE: Jin Ooi, Subhash Thakur

UTC: Piotr Frankowski, Martin Morgeneyer, Maria Paulick

Zeppelin: Harald Wilms

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Agenda of the phone con

1. Introduction, MM, 16:00-16:05

2. Discussion of scientific approach, 16:05-16:15

3. Discussion of experiments and simulations, 16:15-16:30

4. Discussion of reference test materials, 16:30-16:40

5. Discussion of milestones, 16:40-16:50

6. Questions and conclusions, 16:50-17:15

* Indications in black reflect participants comments to the handout

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Overview

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Comments Overview

- Perspectives I and II are at particle level, III and IV are at bulk level. It is suggested to also consider meso parameters (V)

meso parameters already including cohesive forces- Some projects will only consider meso parameters- Meso group is to go beyond particle parameters without looking into bulk

saving time using just a few particles- Micro parameters are difficult to measure

Meso is a possible point to start

WP1 will also take into consider perspective V

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Particle Level

Underlying properties:

- Normal force- Shear force- Rolling / sliding friction- Coefficient of restitution- Particle size- Particle shape- Particle density- Stiffness - Particle roughness- Particle surface structure- …

Focusing on effects

Effective parameters:

- Repulsive force- Cohesion force- Friction force- Coefficient of restitution- Stiffness

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Comments particle level

- Normal force includes cohesive and repulsive forces and is somehow a force displacement behavior

- the coefficient of restitution is important only in some applications such as conveying (but not when particle are already in contact, e.g. storage)

- Particle surface structure, including its roughness, is important for cohesive material

- Structure and roughness to estimate distances between particles and scattering of cohesive forces

- Torsion and rolling friction might be negligible

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Bulk Level

Effective bulk parameters:

- Compressive strength, tensile strength- Scale information: porosity depending on normal stress (compaction)- Flow function- Anisotropy of flow function- Permeability- Size distribution- (Angle of repose)

The participants agreed to always check the results (real world vs. virtual world) !

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Measurement Methods I

Effective particle parameters Testing methods

Normal force AFM

Shear force AFM, Nanoindenter?

Rolling/ sliding friction AFM

Coefficient of restitution Drop Test

Particle size

Particle shape

Particle density Volume/ mass

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Measurement Methods II

Effective bulk parameters Testing methods

Tensile strength Shear test

Porosity depending on normal stress (compaction)

Uniaxial tester

Flow function Shear test

Permeability Filtration (cake)

Anisotropy Uniaxial and biaxial test

Angle of repose „hill” experiment

Size distribution

Friction Shear test

Bulk stiffness (elasticity)

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Comments Measurement

- UE: 3-4 AFM, available equipment to measure coefficient of restitution for small single particle using also a 45degree mirror

- TU BS: set up for measurement of coefficient of restitution for spherical particles

- List of equipment is established for UTC and TU BS, needs to be filled out for the other institutions

Please send your list to pardem@utc.fr- After having an overall list, decisions about what methods to use can be

taken

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MaterialsName + -

Carbonyl Iron Powder

Spherical, Stiff, very cohesive, 3-10µm

Dirty

Glass beads very spherical, different sizes,

Too ideal, Jamming, no monodispers, no good results in measurements but for simulations

Limestone Price Dirty, very irregular

Polypropylene/ Sterol

Spherical, sizes: 100 µm-2,5 mm

Hydroscopic

Plastic pellets

Maltodextrin Explosive !!!

Polymer spray powder

< 100 µm, not cohesive, free flowing powder

gets sticky as a polymer

Aluminum oxides Inert, different shapes and sizes

Slipstick behavior

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Comments Material

- Glass beads are ideal for the investigation of particle size influence- Aluminium oxide could be used for the investigation of shape influence- BASF and Zeppelin will send samples of the proposed material to make

some basic tests in order to get a feeling for the material

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Comments on Milestones

- Deliverables date to Brussels are going to be discussed and changed, e.g. state of the art of calibration in about 3-6 months from now.

- Harald Wilms and Martin Morgeneyer, who lectured last week at the Vienna Summer School, would like to get a feedback to their lecture and would be available to give further presentations, e.g. on industrial view of powder problems