Predictive Performance Scaling Method for Hydrodynamic

Transcription

Predictive Performance Scaling
Method for Hydrodynamic Separators
[Using the Peclet Number]
Mark B. Miller, P.G.
Research Scientist
[email protected]
Chattanooga, Tennessee
(888) 344-9044
13th Tennessee Environmental Conference
March 25-26, 2014
Kingsport
So, how in the heck do I predict an HDS
performance curve for a different particle size
than that used for its lab test?
Get out your slide rule…
….or your TI-30
Hydrodynamic Separators (HDS)
Hydrodynamic Separators
Capture sediment, debris, freefloating oil as pretreatment or
standalone device
Vortex type =
Gravitational &
Centrifugal Forces
Vault type =
Gravitational Forces
LID Technology Selection Pyramid
Evaluating HDS Performance Testing
Lab & Field Test Verifications
(NJCAT, TARP, TAPE, EPA-ETV)
FRUSTRATION !!!
HDS Lab Performance Curves (per NJCAT)
- Tests used different PSDs 100
TSS Removal Efficiency (%)
90
80
70
60
50
40
30
20
10
0
0
10
20
30
40
50
Loading Rate (gpm/sqft)
60
70
80
Common Particle Size Distributions for HDS Lab Tests
- Different PSDs used 100
90
80
% Finer
70
60
50
40
30
20
10
0
1
10
100
Particle Size (microns)
1,000
Peclet Number predicts performance
between different sized particles
Performance is function of:
 Removal efficiency (%)
 Surface area loading rate (gpm/ft2)
 Particle size distribution (microns)
 Specific gravity of particles (2.65)
 Water Temperature
Peclet Number (Pe)
Pe = (D · h · Vs) / Q
D =
H =
Vs =
Q =
Horizontal flow dimension in feet
Vertical flow dimension in feet
Particle settling velocity in feet/sec
Flow rate in cubic feet/second (cfs)
Peclet Number ≠ Froude Number
Peclet Number = Performance predictor
between different particle sizes
Froude Number = Geometric scaling
(sizing) of different device model sizes
HDS Lab Test Using OK-110 PSD (d50 ~ 110 µm)
Test Parameters
d50 = 110 µm
Vs = 0.021 ft/s
Given
Given Calc.
Q
(cfs)
Loading Rate
(gpm/ft²)
RE
(%)
Pe
(unitless)
Tested
Tested
Tested
Calculated
0
0
100
NA
0.20
10.8
89
1.33
SG = 2.65
Given
0.50
27.1
82
0.53
D = 3.3 ft
Given
0.80
43.3
57
0.33
h = 3.83 ft
Given
1.20
64.9
18
0.22
Pe = (D · h · Vs) / Q
Example: Q = 0.2 cfs
Pe = (3.3 ft · 3.83 ft · 0.021 ft/sec) / 0.2 cfs
Pe = 1.33
HDS Performance Curve 110 µm (OK-110 PSD)
100
90
80
70
60
50
40
30
20
10
0
0
10
20
30
40
50
60
70
Calculate Particle Settling Velocity (Vs)
Term
Gs
ρs
ρw
g
T
T
μ
υ
D
Vs
Vs
Vs
Variable
2.65
165.07
62.29
32.20
20.00
68
2.09E-05
1.08E-05
110
0.024
0.02080
0.029
Input Value
Units
Description
Specific gravity of particle
lb/ft3 Density of particle
lb/ft3 Density of water
ft/s2 Acceleration due to gravity
C°
Temperature of water
F°
Temperature of water
lb*s/ft2 Dynamic viscosity of water at given temp.
ft2/s Kinematic Viscosity of water
micron Diameter of particle
ft/s Settling velocity, Cheng Formula
ft/s Settling velocity, Stoke's Law
ft/s Settling velocity, Ferguson & Church
Stoke’s Law Particle Settling Velocities
Particle Size
(µm)
45
50
67
75
90
110
125
Vs
(ft/sec)
0.0085
0.010
0.013
0.014
0.017
0.021
0.024
Performance Summary - 45 µm
Rearrange equation
Q = (3.3 ft · 3.83 ft · Vs) / Pe
RE and Pe constant
Parameters
Q
(cfs)
Loading Rate
(gpm/ft²)
RE
(%)
Pe
(unitless)
d50 = 45 µm
0
0
100
NA
Vs = 0.0085 ft/sec
0.081
4.4
89
1.33
SG = 2.65
0.202
10.9
82
0.53
D = 3.3 ft
0.325
17.5
57
0.33
h = 3.83 ft
0.486
26.3
18
0.22
Loading Rate = Q cfs · 448.83 gpm/cfs / Area ft2
HDS Performance Curves for 45 and 110 µm
100
90
80
70
60
50
40
30
20
10
45µm
110µm
0
0
10
20
30
40
50
60
70
Parameters
d50 = 50 µm
Vs = 0.010 ft/sec
SG = 2.65
D = 3.3 ft
h = 3.83 ft
Q
(cfs)
0
0.10
0.24
0.38
0.57
50 µm
Loading Rate
(gpm/ft²)
0
5.2
12.9
20.6
30.9
67 µm (d50 from NJDEP PSD)
Q
Loading Rate
Parameters
(cfs)
(gpm/ft²)
d50 = 67 µm
0
0
Vs = 0.0.013 ft/sec
0.124
6.7
SG = 2.65
0.310
16.7
D = 3.3 ft
0.495
26.8
h = 3.83 ft
0.743
40.2
RE
(%)
100
89
82
57
18
Pe
(unitless)
NA
1.33
0.53
0.33
0.22
RE
(%)
100
89
82
57
18
Pe
(unitless)
NA
1.33
0.53
0.33
0.22
Parameters
d50 = 75 µm
Vs = 0.014 ft/sec
SG = 2.65
D = 3.3 ft
h = 3.83 ft
Parameters
d50 = 90 µm
Vs = 0.017 ft/sec
SG = 2.65
D = 3.3 ft
h = 3.83 ft
Q
(cfs)
0
0.133
0.333
0.533
0.800
75 µm
Loading Rate
(gpm/ft²)
0
7.2
18.0
28.9
43.3
RE
(%)
100
89
82
57
18
Pe
(unitless)
NA
1.33
0.53
0.33
0.22
Q
(cfs)
0
0.162
0.405
0.648
0.971
90 µm
Loading Rate
(gpm/ft²)
0
8.8
21.9
35.0
52.6
RE
(%)
100
89
82
57
18
Pe
(unitless)
NA
1.33
0.53
0.33
0.22
Parameters
d50 = 110 µm
Vs = 0.021 ft/sec
SG = 2.65
D = 3.3 ft
h = 3.83 ft
Parameters
d50 = 125 µm
Vs = 0.024 ft/sec
SG = 2.65
D = 3.3 ft
h = 3.83 ft
Q
(cfs)
0
0.2
0.5
0.8
1.2
110 µm
Loading Rate
(gpm/ft²)
0
10.8
27.1
43.3
64.9
Q
(cfs)
0
0.229
0.571
0.914
1.371
125 µm
Loading Rate
(gpm/ft²)
0
12.4
30.9
49.5
74.2
RE
(%)
100
89
82
57
18
RE
(%)
100
89
82
57
18
Pe
(unitless)
NA
1.33
0.53
0.33
0.22
Pe
(unitless)
NA
1.33
0.53
0.33
0.22
Performance Curve Data Summary
Removal Efficiency vs. Loading Rate
45 µm
50 µm
67 µm
75 µm
90 µm
110 µm
125 µm
RE
(%)
LR
gpm/ft2
RE
(%)
LR
gpm/ft2
RE
(%)
LR
gpm/ft2
RE
(%)
LR
gpm/ft2
RE
(%)
LR
gpm/ft2
RE
(%)
LR
gpm/ft2
RE
(%)
LR
gpm/ft2
89
4.4
89
5.2
89
6.7
89
7.2
89
8.8
89
10.8
89
12.4
82
10.9
82
12.9
82
16.7
82
18.0
82
21.9
82
27.1
82
30.9
57
17.5
57
20.6
57
26.8
57
28.9
57
35.0
57
43.3
57
49.5
18
26.3
18
30.9
18
40.2
18
43.3
18
52.6
18
64.9
18
74.2
HDS Performance Curves for Different Particle Sizes
100
90
80
70
60
50
40
30
20
45µm 50µm
10
67µm
75µm
90µm
110µm
125µm
0
0
10
20
30
40
50
60
70
80
Real World Comparision of Performance Curves
Parameters
d50 = 63 µm
Vs = 0.013 ft/sec
SG = 2.65
D = 5 ft (19.6 ft2)
h = 2.6 ft
ACME 63 µm Lab Test
Q
Loading Rate
(cfs)
(gpm/ft²)
0
0
0.27
6.4
0.55
12.8
0.83
19.1
1.1
25.5
RE
(%)
100
85
82
80.2
79
ACME Q @ 110 µm by Peclet Method
Q
Loading Rate
RE
Parameters
(cfs)
(gpm/ft²)
(%)
d50 = 110 µm
0
0
100
Vs = 0.021 ft/sec
0.448
11.0
85
SG = 2.65
0.96
22.0
82
D = 5 ft (19.6 ft2)
1.43
32.7
80.2
h = 2.6 ft
1.93
44.2
79
Pe
(unitless)
NA
0.69
0.34
0.23
0.17
Pe
(unitless)
NA
0.69
0.34
0.23
0.17
Parameters
d50 = 110 µm
Vs = 0.021 ft/sec
SG = 2.65
D = 3.3 ft (8.3 ft2)
h = 3.83 ft
HDS 110 µm Lab Test
Q
Loading Rate
(cfs)
(gpm/ft²)
0
0
0.2
10.8
0.5
27.1
0.8
43.3
1.2
64.9
RE
(%)
100
89
82
57
18
HDS Q @ 63 µm by Peclet Method
Q
Loading Rate
RE
Parameters
(cfs)
(gpm/ft²)
(%)
d50 = 63 µm
0
0
100
Vs = 0.013 ft/sec
0.12
6.5
89
SG = 2.65
0.31
16.8
82
D = 3.3 ft (8.3 ft2)
0.50
27.0
57
h = 3.83 ft
0.75
40.6
18
Pe
(unitless)
NA
1.33
0.53
0.33
0.22
Pe
(unitless)
NA
1.33
0.53
0.33
0.22
HDS vs. ACME Peclet Method Performance Curves
100
90
ACME 110µm
80
ACME 63µm test
70
60
50
HDS 63µm
HDS 110µm test
40
30
20
10
0
0
10
20
30
40
50
60
ACME 63 micron
ACME 110 micron
HDS 110 micron
HDS 63 micron
70
HDS 80% TSS Removal Per Storm
100
90
80% TSS Removal Per Storm
80
70
60
50
40
30
20
45µm 50µm
67µm 75µm
90µm
110µm
125µm
y = -0.0127x2 - 0.4361x + 100
10
0
0
10
20
30
40
50
60
70
80
Particle Size and Peak Loading Rate for
80% TSS Removal Efficiency Per Storm Based
on Performance Curves
Particle Size
(µm)
Peak Loading
Rate (gpm/ft2)
45
50
67
75
90
110
125
10.5
12.2
16.0
17.5
21.0
26.0*
30.0
* Exact Loading Rate can be calculated using
equation for slope of performance curve
Example HDS Sizing Charts: 80% TSS Removal per Storm
Particle Size and Loading Rate
Example
Vortex
HDS
Model
Diameter
(ft)
Effective
Treatment
Area
(ft2)
2.5
45 µm
50 µm
67 µm
75 µm
90 µm
110 µm
125 µm
10.5
gpm/ft2
12.2
gpm/ft2
16.0
gpm/ft2
17.5
gpm/ft2
21.0
gpm/ft2
26.0
gpm/ft2
30.0
gpm/ft2
WQTF
(cfs)
WQTF
(cfs)
WQTF
(cfs)
WQTF
(cfs)
WQTF
(cfs)
WQTF
(cfs)
WQTF
(cfs)
4.9
0.11
0.13
0.17
0.19
0.23
0.28
0.33
5.0
19.6
0.46
0.53
0.70
0.76
0.92
1.14
1.31
6.0
28.3
0.66
0.77
1.01
1.10
1.32
1.64
1.89
8.0
50.3
1.18
1.37
1.79
1.96
2.35
2.91
3.36
10.0
78.5
1.84
2.13
2.80
3.06
3.67
4.54
5.24
Water Quality Treatment Flow = (Area · Loading Rate) / 448.83 gpm/cfs
Example: WQTF @ 1.4 cfs for 75 µm = HDS Model 8 ft diameter
Peclet Number scaling method helps make sense of this mess
HDS Lab Performance Curves (per NJCAT)
100
90
80
70
60
50
40
30
20
10
0
0
10
20
30
40
50
60
70
80
Peclet Number (Pe)
Pe = (D · h · Vs) / Q
D =
H =
Vs =
Q =
Horizontal flow dimension in feet*
Vertical flow dimension in feet
Particle settling velocity in feet/sec
Flow rate in cubic feet/second (cfs)
* Vortex: use diameter of device for D
Vault: use long axis of device for D
Remember This Date:
September 10, 2016
“Battle at Bristol”
Go Vols, Beat the Hokies!
It’s all about Good Clean Water…....
Tennessee River, Chattanooga
Thank you!
Mark Miller
(423) 870-8888
[email protected]

Predictive Performance Scaling Method for Hydrodynamic

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