Experimental investigation of hydrodynamics in SiSiC foam packed reactors
Measurement system
The investigations of hydrodynamics in foam packed columns were carried out with the ultrafast electron beam X-ray computed tomography system ROFEX III. The measurements were carried out with a temporal resolution of 1 ms and a spatial resolution of 1 mm. Having two measurement planes with an axial distance of about 14 mm, the system provides a detailed insight in the morphology and statistical key parameters of the liquid pulses. |
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Micro-CT images of the applied foams with pore densities of 20 ppi, 30 ppi and 45 ppi (from left to right) | Schematical drawing of the ultrafast X-Ray scanner ROFEX III |
Results
Comparison pulse flow regime
Depending on operation conditions, partially and fully developed pulse flow ocurrs in solid foam packed reactors. Within the investigated measurement range pulse flow has been found at three gas/liquid velocity combinations (A, B, C) corresponding to gas and liquid superficial velocities uG and uL, respectively, of:
- A: uL=0.03 m s-1 | uG=1.0 m s-1
- B: uL=0.04 m s-1 | uG=0.8 m s-1
- C: uL=0.04 m s-1 | uG=1.0 m s-1.
Varying operation conditions, the trend of cross sectional liquid saturation measured within solid foams can be seen in the following table.
20 ppi |
30 ppi |
45 ppi |
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© HZDR |
The videos shown below are representative excerpts of one second length from a comprehensive set of experiments which provide insight in the complex dynamics of pulse flow. The data is presented in terms of liquid saturation βL, i.e. liquid volume per void fraction.