| Figures |
6 |
| Tables |
8 |
| Nomenclature |
8 |
|
1 |
Background and Introduction |
11 |
| |
1.1 |
Overview and Motivation |
11 |
|
1.2 |
Measurement Techniques |
12 |
|
1.3 |
Summary of Previous Work |
14 |
|
2 |
Theory |
14 |
| |
2.1 |
Electrical-Impedance Tomography (EIT) |
14 |
|
2.2 |
Gamma-Densitometry Tomography (GDT) |
19 |
|
2.3 |
Combined EIT and GDT for Three-Phase Measurements |
21 |
|
3 |
Diagnostic Systems |
24 |
| |
3.1 |
EIT Apparatus |
24 |
|
3.2 |
GDT Apparatus |
26 |
|
4 |
Experiments |
27 |
| |
4.1 |
Benchtop Validation Test |
27 |
|
4.2 |
Sandia's Slurry Bubble-Column Reactor (SBCR) Facility |
29 |
|
4.3 |
Experimental Procedure for Measurement in Sandia's SBCR |
32 |
|
4.4 |
Experimental Material Properties |
34 |
|
4.5 |
Sources of Uncertainty |
35 |
|
5 |
Experimental Results and Discussion |
36 |
| |
5.1 |
Benchtop Validation Measurements |
36 |
|
5.2 |
Two-Phase Measurements |
37 |
|
5.3 |
Three-Phase Measurements |
45 |
|
6 |
Conclusions and Future Recommendations |
52 |
|
References |
53 |
|
Appendix |
56 |
| |
|
LIST OF FIGURES |
|
Figure 1 |
Schematic of an EIT system applied to an electrically insulating
(nonconducting) vessel |
16 |
|
Figure 2 |
Schematic of an EIT system applied to an electrically conducting
vessel |
17 |
|
Figure 3 |
Photograph of verification experiment showing the EIT
electronics, the electrode rod with seven copper ring electrodes
(the top eight ring shown is a plastic seal), and the standpipe |
25 |
|
Figure 4 |
Photographs of the circuit boards inside the EIT electronics box |
26 |
|
Figure 5 |
A schematic of the GDT system in the horizontal plane |
27 |
|
Figure 6 |
Schematic of verification experiment consisting of an electrode
rod inserted coaxially in an electrically conducting standpipe
filled with nonconducting solid polystyrene particles and liquid |
28 |
|
Figure 7 |
Photograph of the Sandia slurry bubble-column reactor facility.
Also shown is the vault for the gamma source mounted on the two-axis
automated traverse |
29 |
|
Figure 8 |
Photograph of a cross sparger similar to that used in this study
to inject air into the bottom of the bubble column |
30 |
|
Figure 9 |
Schematic of EIT system applied to Sandia's slurry bubble-column
reactor (SBCR). Shown on the right is a photograph of the SBCR
(0.48-mID). The bottom left shows predictions of voltage contours in
a cross-section of the SBCR for two cases, one of constant
conductivity in the top half, and one of variable conductivity in
the bottom half |
31 |
|
Figure 10 |
(a) Computational mesh corresponding to one-quarter of the
interior of the SBCR with the EIT rod inserted along a diameter. (b)
Voltage contours computed for a uniform electrical conductivity
throughout the domain with current injection from electrode 4 |
33 |
|
Figure 11 |
Plot of the EIT reconstructed particle-bed height versus the
measured particle-bed height in the steel standpipe |
36 |
|
Figure 12 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 103 kPa and a
superficial gas velocity = gu 10 cm/s |
39 |
|
Figure 13 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 103 kPa and a
superficial gas velocity = gu 15 cm/s |
39 |
|
Figure 14 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 103 kPa and a
superficial gas velocity = gu 20 cm/s |
40 |
|
Figure 15 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 103 kPa and a
superficial gas velocity = gu 25 cm/s |
40 |
|
Figure 16 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 207 kPa and a
superficial gas velocity = gu 10 cm/s |
41 |
|
Figure 17 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 207 kPa and a
superficial gas velocity = gu 15 cm/s |
41 |
|
Figure 18 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 207 kPa and a
superficial gas velocity = gu 20 cm/s |
42 |
|
Figure 19 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 207 kPa and a
superficial gas velocity = gu 25 cm/s |
42 |
|
Figure 20 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 310 kPa and a
superficial gas velocity = gu 10 cm/s |
43 |
|
Figure 21 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 310 kPa and a
superficial gas velocity = gu 15 cm/s |
43 |
|
Figure 22 |
Comparison of symmetric radial gas volume fraction profiles from
EIT and GDT for a column pressure colp = 310 kPa and a
superficial gas velocity = gu 20 cm/s |
44 |
|
Figure 23 |
Plot of the bulk-averaged gas fraction as a function of
superficial gas velocity and column pressure, from GDT measurements |
44 |
|
Figure 24 |
Plot of the bulk-averaged gas fraction as a function of
superficial gas velocity and column pressure, from EIT measurements |
45 |
|
Figure 25 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 0%, with a column
pressure colp = 103 kPa and a superficial gas
velocity nom= gu
10 cm/s. |
47 |
|
Figure 26 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 0%, with a column
pressure colp = 207 kPa and a superficial gas
velocity nom= gu
10 cm/s. |
48 |
|
Figure 27 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 4%,
with a column pressure colp = 103 kPa and a
superficial gas velocity nom= gu
10 cm/s. |
48 |
|
Figure 28 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 4%,
with a column pressure colp = 207 kPa and a
superficial gas velocity nom= gu
10 cm/s. |
49 |
|
Figure 29 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 8%,
with a column pressure colp = 103 kPa and a
superficial gas velocity nom= gu
10 cm/s. |
49 |
|
Figure 30 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 8%,
with a column pressure colp = 207 kPa and a
superficial gas velocity nom= gu
10 cm/s. |
50 |
|
Figure 31 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 4%, with a column
pressure colp = 103 kPa and a superficial gas
velocity = gu
10 cm/s, and calculated
with a conductivity ratio
~
41.1
~ r )( ~
l
~ = |
50 |
|
Figure 32 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 4%, with a column
pressure colp = 207 kPa and a superficial gas
velocity = gu
10 cm/s, and calculated
with a conductivity ratio
~
41.1
~ r )( ~
l
~ = |
51 |
|
Figure 33 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 8%,
with a column pressure colp = 103 kPa and a
superficial gas velocity = gu
10 cm/s, and calculated
with a conductivity ratio
~
94.0
~ r
)( ~ l
~ = |
51 |
|
Figure 34 |
Radial material phase-volume-fraction profiles for a nominal
slurry concentration
• 8%,
with a column pressure colp = 207 kPa and a
superficial gas velocity = gu
10 cm/s, and calculated
with a conductivity ratio
~
94.0
~ r )( ~
l
~ = |
52 |
| |
| LIST OF TABLES |
|
Table 1 |
Various industrial application that would benefit from improved
capability to measure spatial volumetric phase fractions |
12 |
|
Table 2 |
Some noninvasive diagnostic techniques reported in the
literature used to measure spatial volumetric phase fractions |
13 |
|
Table 3 |
Operating conditions for the two- and three-phase tests in the
SBCR |
32 |
|
Table 4 |
Properties of the phase materials used for the material
distribution reconstructions |
35 |
|
Table 5 |
Measured and predicted particle-bed heights for 6 different
tests, 3 with copper electrodes and 3 with stainless steel
electrodes |
37 |
|
Table 6 |
Comparison of EIT and averaged GDT measurements of gas volume
fractions for the 11 different two-phase operating conditions listed
in Table 4 |
38 |
|
Table 7 |
Predicted bulk-averaged phase volume fractions for the 6
three-phase cases measured and listed in Table 4 |
46 |
|
Table 8 |
Predicted bulk-averaged volumetric phase-fractions for the cases
of 4% and 8% nominal solids loading, using a scaled conductivity
ratio |
47 |
