Fragmentation Lab
Contact
Dr. Bettina Scheu
Dr. Ulrich Küppers
Laboratory Phone: +49 89 2180 4661
Equipment
- 4 Shock Tube Apparatus (fragmentation bombs): rapid decompression experiments at RT – 850°C, 0.1 – 50 MPa
4 Shock Tube Apparatus (fragmentation bombs)
- Large low pressure tank (3 m long, 0.4m wide) and several high pressure autoclaves, separated by a set of 1-3 rupture discs
- Rapid decompression experiments using Argon gas to analyse fragmentation behaviour (threshold, speed, efficiency) at 20°C - 900°C and 0.1 - 50 MPa
- Phreatic Explosion experiments with water saturated samples, P&T sensors installed in the range of 20°C – 400°C and 0.1 – 25 MPa.
- Measurement of Particle ejection speed
- Analysis of natural samples and magma analogues
- Full recoverage of particles -> GSD
- Pulse-decay permeability measurements
- several sample sizes (mm): 19x50, 25x60, 60x60, 34x70
- high-speed video recording from 50 to >50.000 fps
Description of facility:
The shock-tube devices are tailor-made and can be operated with a variety of set-ups to investigate aspects of fragmentation behaviour or natural and analogue material as: fragmentation threshold, fragmentation speed and permeability via a pulse-decay method. The shock-tubes operate from room temperature up to 900°C and at pressures between 1 bar (atmospheric) to 50 MPa applied pressure using by default argon gas for pressurization (pressurization by nitrogen or H2O vapour is also possible). Depending on the set-up, the experiment is monitored by a varying number of pressure and temperature sensors. The experimental pyroclasts are fully recoverable and thus allow determining the fragmentation efficiency.
(e.g. Spieler et al., EPSL, 2004)
