5-2-3 slurry mixing w pulse jet mixers_perry meyer[1]
TRANSCRIPT
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
1/38
Mixing Sludges & Slurries withPulsed Jets: Some mixing theory &Test Results
MixingMixing SludgesSludges & Slurries with& Slurries withPulsed Jets: Some mixing theory &Pulsed Jets: Some mixing theory &Test ResultsTest Results
Slurry Retrieval, Pipeline Transport & Plugging & Mixing Workshop
January 14 - 18, 2008, Orlando, Florida.
Perry A. Meyer
Pacific Northwest National Laboratory
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
2/38
2
Unsteady Jet Mixers at HanfordUnsteadyUnsteady Jet Mixers at HanfordJet Mixers at Hanford
Retrieving from storage
Underground, 1 -
2ft risers
Limited access for equipment
2 -
300hp mixer pumps (baseline)
Treating & vitrifying waste
Closed black
cells
No maintenance for 40 years
Rotating horizontal opposed jets Pneumatic pulsed jets
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
3/38
3
Turbulent JetsTurbulent JetsTurbulent Jets
ujNear Field Far Field
dj
zu(z)
ud A
(z)
High Reynolds number far field
Constant spread angle
Peak & ave. velocity decrease Thrust/force is constant
Flow rate increases (entrainment)
Energy decreases
Constant Reynolds number
q(z) / qj ~ z / d
(z) = z
u(z) = cjujdj/ z
Re (z) = Rede(z)/ej = d / z
F(z) = Fj
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
4/38
4
Turbulent Jets, cont.Turbulent Jets, cont.Turbulent Jets, cont.
r
(r)
u(r)
Same results for impinging & attaching jets
Different constants
Wall shear stress
True independent of nozzle cross-sectional areaApproximately true in near-far-field transition
Allows one to approximately obtain flow fields, fluxes, forces, etc
Similar relations for dense jets
w (r) ~ uj
2(dj/r)2
z / dj, r / dj = 15 30
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
5/38
5
Jets as mixersJets as mixersJets as mixers
Axial flow impeller: ND ~ uj dj/T
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
6/386
Downward vertical jet mixersDownward vertical jet mixersDownward vertical jet mixers
Centered Jet(s)
~T/2
uT
uuw
Jet rings(s)
uT ~ uj(dj/T)
~ ujdj/ T2
uuw ~ uj Nj (dj/ T) f(H/ T)
tuw ~ T2/ ujdj Nj f2(H/ T)
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
7/387
GeometryGeometryGeometry
Nozzle geometry Cross-section: No effect in far field- only area counts
Convergence: extra thrust from pressure
Stand-off No effect for h/dj < 6, little effect for h/T
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
8/38
8
Intermittent JetsIntermittent JetsIntermittent Jets
Dimensionless pulse timedetermines regime
uS
uP
u
uV
uC
z
Steady
Short pulse
uP
uFLong pulse
Steady
Np = tpud /d
NP
< 4 vortex ring4 < NP
vortex ring with tail
4
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
9/38
9
Unsteady effects on mixing/mobilizationUnsteady effects on mixing/mobilizationUnsteady effects on mixing/mobilization
Would like to utilize steady mixing knowledge base Can we find simple corrections for unsteady effects or are we
dealing with fundamentally new phenomena?
Must consider relative time scales Flow establishment/mixing times compared with pulse time
Duty cycle What happens when the jet is off?
Other time scales Erosion rates
Settling rates
Etc.
Two new parameters are introduced Relative pulse volume
Duty cycle
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
10/38
10
Pulse jet mixersPulse jet mixersPulse jet mixers
PJMs in the WTP V (range)
N (range) Pvf (range)
DC (range)
Dpjm (range)
T
H
H
djuj
V
Vpjm
uj(t)
tp
tc
Mixing modes drive
refill
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
11/38
11
Important parametersImportant parametersImportant parameters
Operational
Geometry
N number jets
Uj jet velocity (peak)dj /T nozzle diam.
p = Vp /V pulse size
DC = tp/tc duty cyclegeometry
Waste physicalconfiguration
Normal/off-normaloperations
Uniform
Settled layers
Physical &
rheologicalproperties
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
12/38
12
Pulse Jet Mixing Studies at Battelle/PNNLPulse Jet MixingPulse Jet Mixing Studies atStudies at Battelle/PNNLBattelle/PNNL
Physical regimes Transitional flow
unsteady
Non-settling/non-Newtonian
Settling- wide particle size &density range, agglomerates
Heels- cohesive/non-cohesive In situ gas generation
Mixing requirements Stagnation/caverns
Off-bottom suspension- VJS Vertical distribution
Gas hold-up & release behavior
Scaled testing program Simulant development
Physical/chemical
Transparent/opaque
1/2/3 phase
Testing
Bench scale - 40m3
Single & multi jets
simplified & prototypicgeometries
Scale up Rating, not designing
Similarity, physical,empirical
Instrumentation
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
13/38
13
Non-Newtonian PJM Test ProgramNonNon--Newtonian PJM Test ProgramNewtonian PJM Test Program
Technical basis
Develop scaled testing approach Validate approach- limited testing at scales
Rate existing designs
(3 unique designs in WTP)Improved PJM designs
PJM/sparge hybrid designs
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
14/382/26/2008
Theory of PJM Operation with Non-Newtonian Materials
Theory of PJM Operation with NonTheory of PJM Operation with Non--Newtonian MaterialsNewtonian Materials
Model problem: Cavernformation Initially gelled material
Representative of restart aftermixing shutdown
Good mixing system willeliminate cavern
Rheological model Static gel formation with shear
strength s Bingham plastic laminar flow
rheology with yield stress 0 andconsistency K Turbulent flow characteristics
determined by high shearconsistency ~K
Shea rStress
(Pa)
Stra in R ate
0
s K
~K
stat ic
laminar
turbulent
Illustrating Rheological Characteristics ofWaste Slurry
Un-yieldedmaterial
Turbulent flow
Distinct
interface
Typical Pulse Jet Mixer System
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
15/38
15
Cavern Formation from a Steady JetCavern Formation from a Steady JetCavern Formation from a Steady Jet
Turbulent wall jet
u(z)= cJud d / z
Force balance at staticinterface
f = Cfu2 / 2
HC / T = a(d/T)Re1 / 21/ 2
Re = ud2 / s
ud
HC
T
Cavernboundary
d
Path ofwall jet
Vp
u(z)z
zcTurbulent
mixingcavern
Stagnantmaterial
at zC HC + T / 2 f = s
Reynolds number dependence
C f , cJ = f(Red ) a ~ R ed
Red = udd / k
Yield Reynolds Number
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
16/38
16
Theory of PJM Operation in Non-NewtonianMaterials
Theory of PJM Operation in NonTheory of PJM Operation in Non--NewtonianNewtonianMaterialsMaterials
Cavern Formation from aSteady Jet Turbulent jet theory with force
balance at interface predictscavern height
Yield Reynolds number Ratio fluid force to material
strength
Effects of pulsation Ratio PJM drive time to flow
establishment time
Predicted cavern height
Re=u02/
tD/ tss ~ Vp/ d0
3Re
u0
Und istu rbedmater ial
H C
D T
z
u(z)
Turbu lentCavern
z c
Pl ug m otion
Non-dimensional cavern height as a function of yieldReynolds number for a single PJM in Laponite
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 1000 2000 3000 4000 5000
Yield Reynolds Number Re
0.875 inch Steady Jet
1.0 inch Pulse Jet
2.0 inch Pulse Jet
HcDT
= a d0DT
Re 1/ 2
1 exp(c Vpd0
3Re
)
1/ 2
12
Re = u02/s
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
17/38
17
Single-PJM Cavern Tests (laponite)SingleSingle--PJM Cavern Tests (PJM Cavern Tests (laponitelaponite))
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 1000 2000 3000 4000 500
2.2cm Steady Jet
2.5cm Pulse Jet5.1cm Pulse Jet
(Eq. 10)
(Eq. 10)(Eq. 10)Norm
alizedCave
rnHeightHC
/T
Yield Reynolds Number Re
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
18/38
18
Test to Verify Scaled Testing ApproachTest to Verify Scaled Testing ApproachTest to Verify Scaled Testing Approach
1PJM Tests Simulant selection
Verify cavern formation theory
4PJM Tests Downward firing PJMs
Performed at 3 scales
Simulants Laponite
Transparent
Adjustable shear strength
Kaolin/Bentonite Clay Opaque
Adjustable yieldstress/consistency
Test conditions Rheology (20 -120 Pa) Velocity (3-30 m/s)
Types of measurements
Cavern height (Laponite)
Breakthrough velocity (clay &Laponite)
Upwell velocity (clay)
u0
HC
DT
TurbulentCavern
BreakthroughLocation
Upwell
Velocity
H
v
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
19/38
19
Small Scale Test StandsSmall Scale Test StandsSmall Scale Test Stands
Battelle 1/4-scale 4PJM Test Vessel
34 in. diameter
250 gallons
Acrylic vessel
Compressedair/vacuum PJMdrive system
SRNL 1/9-scale 4PJM Test Vessel
17 in. diameter
~30 gallons
Acrylic vessel
Compressedair/vacuum PJMdrive system
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
20/38
20
Large-Scale Test Stand at BattelleLargeLarge--Scale Test Stand at BattelleScale Test Stand at Battelle
Battelle 336 4 PJM TestVessel
~13 ft. diameter, ~12,000gallons
Steel construction
Prototypic AEACompressed air PJM drivesystem
Pulse tube prior toinstallation
24 in. diameter
2 in. conical nozzle
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
21/38
21
Scaling Data ComparisonsScaling Data ComparisonsScaling Data Comparisons
Comparison of cavern position for tanks of 3 different scales with
Laponite simulant.
Comparison of cavern position for tanks of 3 different scales wiComparison of cavern position for tanks of 3 different scales withth
Laponite simulant.Laponite simulant.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0 200 400 600 800 1000 1200 1400 1600 1800
Yield Reynolds Number Re
Non-dimen
sionalCavernH
eightHc/D
336
APEL
SRS
Break Through 336APEL Break Through
SRS Break Through
)Linear (336
)Linear (APEL
)Linear (SRS
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
22/38
22
Scaling Data ComparisonsScaling Data ComparisonsScaling Data Comparisons
Comparison of surface breakthrough velocity for tanksof 3 different scales with Laponite & clay simulants.
Comparison of surface breakthrough velocity for tanksComparison of surface breakthrough velocity for tanksof 3 different scales with Laponite & clay simulants.of 3 different scales with Laponite & clay simulants.
Laponite Breakthrough
Clay Breakthrough
Laponite Breakthrough
Clay Breakthrough
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
23/38
23
Gas hold-up & release- tests at 3 scalesGas holdGas hold--up & releaseup & release-- tests at 3 scalestests at 3 scales
0
1
2
0 50 100 150
APEL 2-25-04 (18 Pa, 14 cP)336 7-22-04 (20 Pa, 18 cP)SRNL 12/13/03 (16 Pa, 19 cP)
RetainedGas(vol%)
Time (min)
0
2
4
6
8
10
12
0 100 200 300 400
SRNL 12/13/03 (1:9 - 16 Pa)
APEL 12/02/03 (1:4.5 - 20 Pa)
336 7/23/04 (1:1 - 20 Pa)
RetainedGas(vol%)
Number of PJM Cycles
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
24/38
24
Baseline DesignsBaseline DesignsBaseline Designs
UC
I Cavern only
III Breakthrough with slowperipheral movement
II Breakthrough,
frozenzones
IV Full turbulent mixing
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
25/38
25
Improved PJM designsImproved PJM designsImproved PJM designs
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
26/38
26
Air sparging in Bingham Plastic SlurryAirAir spargingsparging in Bingham Plastic Slurryin Bingham Plastic Slurry
0
20
40
60
80
100
120
140
160
0 10 20 30 40 50 60
118"118"
83"83"
66"66"
ROBZOI
Avg.
C
haracteristicDiameter(DROB,
DZOI;in)
Flow (Q, ACFM)
DZOI = 34Q0.34
DROB = 11Q0.34
(DZOI + DROB)/2=22Q0.34
Cone Tank Bottom
Liquid Surface
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
0 10 20 30 40 50 60 70 80Distance from Cente r of Tank (in.)
Tank
Elevation
(in.)
40 acfm15 acfm5 acfmSparge TubeLiquid SurfaceTank Wall
DS
ROB
ZOI
2/3 ZOI
SPARGE
TUBE
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 5 10 15 20
206 acfm
68 acfm
GasVolume
(vol%)
Time (min)
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
27/38
27
PJM/air-sparge hybrid designsPJM/airPJM/air--spargesparge hybrid designshybrid designs
59 1/8 in. Diameter
PJM Tube
Recirculation PumpDischarge Line
70 in. Diameter
Recirculation PumpSuction Line
40 Sparger
16 1/2 in. Diameter
61 3/4 in. Diameter30 in. Diameter40
48
Recirculation PumpDischarge Line
37In
14 3/4in17 1/8in
45
Perimeter PJM
1 1/4in1 1/4 in
Center PJM
Pump DischargeLine
34in
3 7/8in
~ 4 in
Pump Suction Line
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
28/38
28
Final Design Mixing PerformanceFinal Design Mixing PerformanceFinal Design Mixing Performance
PJM Only PJMs + SpargingPJMs + Pump (1 Disch. Noz) Linear (PJM Only)
10-1
100
10-2
10-1
LS 35-36 PaHSLS 33-43 PaQSLS 32 Pa AZ+AFAQSLS 13 Pa AZ+AFAQSLS 3 Pa AZ+AFA
QSLS 34 Pa Clay
QSLS 13 Pa Clay
GasVolumeFractio
n(vol%)
Superficial Velocity (mm/s)
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
29/38
29
M3- Rating WTP Mixing SystemsM3M3-- Rating WTP Mixing SystemsRating WTP Mixing Systems
Rate mixing system designs for balance of WTP vessels Normal operations & mixing restart
Broad range of potential waste conditions Non-cohesive (settling) solids - cohesive solids
Wide range of solids size, density, slurry rheology
18 different vessel/mixing system geometriesPrimary metrics Off-bottom suspension
Vertical solids distribution Blend times
Work in 3 phases: non-cohesive, cohesive, gas handling
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
30/38
30
Preliminary tests with non-cohesive solidsPreliminary tests with nonPreliminary tests with non--cohesive solidscohesive solids
Simulants Glass spheres (low grade), S ~ 2.47
3 sizes: ds = 63-100, 150-210, 600-800m 2 solids loadings: s = 0.005 & 0.015
Vessel geometries 34-in., 1/13.4-scale of HLP-22
12 tubes, 0.3 & 0.45-in nozzles (4 & 6-in. full scale)
Operational Pulse volume fraction p = 0.025 - 0.10 Duty cycle: DC = 0.18, 0.36, 0.5, 1 (steady)
Measurements Ujs & peak cloud height
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
31/38
31
Some off-bottom suspension resultsSome offSome off--bottom suspension resultsbottom suspension results
y = 19.20x -
y = 33.36x -
y = 25.69x -
y = 34.73x -
3
5
7
9
3 4 5 6 7
Nozzle Diameter, dj (equiv. plant scale, in.)
pulsed, 0.5% solids pulsed, 1.5% solids
steady, 0.5% solids steady, 1.5% solids
y = 3.46x -
y = 5.72x
-
3
4
5
6
7
0.00 0.25 0.50 0.75 1.00Duty Cycle, DC
4-in. 6-in.
y = 3.75x -
y = 1.99x -
2
3
4
5
6
7
8
0.00 0.05 0.10 0.15
Pulse Volume Fraction, fp
4-in. pulsed, DC=0.18 4-in. pulsed, DC=0.33
6-in. pulsed, DC=0.18 6-in. pulsed, DC=0.33
4 in. Steady 6 in. Steady
y = 1.24x 0.23
y = 0.96x 0.27
y = 0.22x 0.49
1
10
100 1000Volume Mean Particle Diameter, dS (mm)
DC=0.18 DC=0.33 DC=1.0, Steady
Preliminary data for information only
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
32/38
32
Correlating just-suspended velocityCorrelating justCorrelating just--suspended velocitysuspended velocity
Assume Zwietering values for un-tested parameters
Ucs= k(H/
D )
0.14
g
0.5
(s1)
0.43
(
D )
1.3
(ds)a5 (dj )
a6 (100ss )a7 (DC)a8 (p /(1+ p))
a9
D =D/
Steady Pulsed
k 0.78 0.23
ds 0.47 0.26
dj -1.3 -1.06
Ss 0.23 0.34
DC - -0.06
p - -0.18
Preliminary data for information only
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
33/38
33
Data correlation: off-bottom suspensionData correlation: offData correlation: off--bottom suspensionbottom suspension
Steady Ujs
y = 1.00x +
0.00
R2 = 0.97
0
2
4
6
8
10
0 2 4 6 8 10
measred Ucs
Unsteady Ujs based on peak. v
y = 1.00x +
0.01
R2 = 0.97
0
2
4
6
8
10
0 2 4 6 8 10
measred Ucs
Suggests pulsation effects small at low concentration
Scale-up to plant conditions: design likely inadequate
More testing at additional scales & higher solids required
Preliminary data for information only
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
34/38
34
Cloud height dataCloud height dataCloud height data
0.25
0.50
0.75
1.00
1.25
2 3 4 5 6 7 8Jet Velocity (
DC=1 DC=0.5 DC=0.33 DC=0.1
0.25
0.50
0.75
1.00
1 2 3 4 5 6 7 8
Jet Velocity (m
100 micron pulsed 200 micron pulsed 800 micron puls
100 micron steady 200 micron steady 800 micron stea
Preliminary data for information only
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
35/38
35
Simple energy argument Energy per pulse ~ change in potential energy of solids
pFH ~
s
d FH =
u2
2(s1)gHc
HC
D~ F
D
pd
sF
D=
u2
2(s1)gD
Attempt correlation of the form
HCD
~ FDa1p
a2d
a3s
a4include ds /D or us / u
Correlating cloud-heightCorrelating cloudCorrelating cloud--heightheight
Preliminary data for information only
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
36/38
36
k U s d ds/T p DC
Steady 2.8 2 -0.56 1.7 -1.1 - -
Pulsed 7.1 2 -1.1 1.0 -0.5 0.3 0.25
Correlation of cloud-height dataCorrelation of cloudCorrelation of cloud--height dataheight data
Correlation of pulsed-jet cloud-height
y = 1.00x - 0.01
R2
= 0.95
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Hc/ T - 0.25
Correlation of steady-jet cloud-heig
y = 1.00x + 0.1
R2
= 0.94
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0.0 0.2 0.4 0.6 0.8 1.0 1.2
Hc/ T -0.25
Preliminary data for information only
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
37/38
37
Summary of findingsSummary of findingsSummary of findings
Just suspended velocity
Unsteady effects minor DC effects negligible
There is evidence this breaks down at higher concentrationwhere time to suspend > drive time
Similar solids size effect Concentration exponent 2x
Effect of nozzle size as expected
To be sure, need more data
-
8/7/2019 5-2-3 Slurry Mixing w Pulse Jet Mixers_Perry Meyer[1]
38/38
Summary, cont.Summary, cont.Summary, cont.
Vertical distribution
Strong bulk density stratification effect Unsteady effects appear to dominate
Exponents on DC & PVF
Fundamental behavior
Weak solids size dependence: Define UJH (just to H). Then UCH ~ ds
0.25
Strong concentration effect: UCH~ s 0.5
Strong pulsation effect: UCH~ p -0.5