7/31/2019 RedValve - Mixing in Storage Tanks
1/49
2009 Red Valve Co. / Tideflex Technologies. All rights reserved.
The Science of Mix ing Water Storage Tanks
New England Water Works Associat ionNew England Water Works Associat ion
2009 Spr ing Joint Regional Conference and Exhibit ion2009 Spr ing Joint Regional Conference and Exhibit ion
Apr il 1Apr il 1 --2, 20092, 2009Worcester, MAWorcester, MA
Presented by:Presented by:
Michael Duer, P.E., Chief Engineer, Red Valve Co.Michael Duer, P.E., Chief Engineer, Red Valve Co.
7/31/2019 RedValve - Mixing in Storage Tanks
2/49
Ground Level Tanks (Rectangular)Ground Level Tanks (Rectangular) Ground Level Tanks (Circular)Ground Level Tanks (Circular)
Elevated TanksElevated Tanks
StandpipesStandpipes
Types of Water Storage TanksTypes of Water Storage Tanks
Tideflex Technologies Tideflex Mixin g System
7/31/2019 RedValve - Mixing in Storage Tanks
3/49
1)1) Minimize ShortMinimize Short--Circuiting and Stagnant AreasCircuiting and Stagnant Areas
(SEPARATE INLET AND OUTLET PIPE)(SEPARATE INLET AND OUTLET PIPE)
2)2) Achieve Complete Mixing During Fill CycleAchieve Complete Mixing During Fill Cycle
(MIXING TIME LESS THAN FILL TIME)(MIXING TIME LESS THAN FILL TIME)
3)3) Achieve Adequate TurnoverAchieve Adequate Turnover
(FLUCTUATE LEVELS)(FLUCTUATE LEVELS)
** MAINTAIN ADEQUATE DISINFECTANT RESIDUAL **
How to Maintain Water Quality in ReservoirsHow to Maintain Water Quality in Reservoirs
COMBINATION OF MIXING SYSTEM DESIGN ANDOPERATION/FLUCTUATION OF THE TANK
DESIGN
OPERATIONS
7/31/2019 RedValve - Mixing in Storage Tanks
4/49
MeshMesh
Velocity Contour/VectorVelocity Contour/Vector
Computational Fluid Dynamics (CFD) ModelingComputational Fluid Dynamics (CFD) Modeling
7/31/2019 RedValve - Mixing in Storage Tanks
5/49
20062006 AwwaRFAwwaRF ProjectProject-- Red Valve & Georgia TechRed Valve & Georgia Tech
Physical Modeling Of Mixing in Water Storage TanksPhysical Modeling Of Mixing in Water Storage Tanks
7/31/2019 RedValve - Mixing in Storage Tanks
6/49
Short Circuiting
First In, Last Out (Last in, First Out)First In, Last Out (Last in, First Out)
Water in Close Proximity to Inlet/Outlet isWater in Close Proximity to Inlet/Outlet isContinually Turned Over. Water away fromContinually Turned Over. Water away fromInlet/Outlet stagnates.Inlet/Outlet stagnates.
Some States Now Mandate Separate Inlet/OutletSome States Now Mandate Separate Inlet/OutletPipesPipes
Common I nlet / Outlet Separate I nlet / Out let
7/31/2019 RedValve - Mixing in Storage Tanks
7/49
Turbulent Inlet Jet (Only source ofTurbulent Inlet Jet (Only source ofEnergy) into LargeEnergy) into Large WaterbodyWaterbody
Velocity Discontinuity between Inlet andVelocity Discontinuity between Inlet andAmbient yields EntrainmentAmbient yields Entrainment
Circulation Patterns form due toCirculation Patterns form due toConservation of MomentumConservation of Momentum
Can be Strongly Dampened byCan be Strongly Dampened by
Temperature Differentials (+ andTemperature Differentials (+ and-- Buoyancy)Buoyancy)
Hydrodynamic Mixing
Tideflex Technologies Tideflex Mixin g System
7/31/2019 RedValve - Mixing in Storage Tanks
8/49
I NLET I N A SUMPI NLET I N A SUMP
Does not allow jet to develop completelyDoes not allow jet to develop completely
DISCHARGE ABOVE WATER SURFACEDISCHARGE ABOVE WATER SURFACE
Does not allow jet to develop completelyDoes not allow jet to develop completely
Inlet Configurations
to Avoid
7/31/2019 RedValve - Mixing in Storage Tanks
9/49
Mixing time (hours) = K (V2/3 / M1/2)
K = Coefficient (based on Mixing Efficiency ofPipe/Manifold)
V = Volume of water in tank at start of fill, feet3M = Momentum = flow rate x velocity (Q * U)
Q = Inflow rate, cfs
U = Inflow velocity, feet per second
Empirical Mixing Time EquationHow LongHow LongdoYoudoYouNeed to Fill Tank to Mix it?Need to Fill Tank to Mix it?
Caution:Caution: No Variables in Equations or Limitations ofNo Variables in Equations or Limitations of
Equation for Considering Temperature DifferencesEquation for Considering Temperature Differences
Between Inlet Water and Tank WaterBetween Inlet Water and Tank Water
7/31/2019 RedValve - Mixing in Storage Tanks
10/49
Mixing Time Comparison (1 MG Reservoir)Mixing Time Comparison (1 MG Reservoir)VelocityVelocity makes signif icant reduct ion in Mixing Timemakes signif icant reduct ion in Mixing Time
MIXING TIME (OKITA & OYAMA)48" Pipe vs. 12" Pipe
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
500 1000 1500 2000 2500FLOW (gpm)
MIXINGTIME
(HOURS)
48" I.D. Pipe
12" I.D. Pipe
7/31/2019 RedValve - Mixing in Storage Tanks
11/49
7/31/2019 RedValve - Mixing in Storage Tanks
12/49
Multiple Inlet Ports Result in Up to 50% FasterMultiple Inlet Ports Result in Up to 50% Faster
Mixing Compared to Single InletsMixing Compared to Single Inlets
Georgia Institute of Technology
and Red Valve Company
2006 AwwaRF Project
7/31/2019 RedValve - Mixing in Storage Tanks
13/49
Multiple Inlet Ports Result inMultiple Inlet Ports Result in
Significantly Faster MixingSignificantly Faster Mixing
Single Shell Penetration 5-Port TMS
SCALE MODELING OF 1MG RESERVOIR
Animations courtesy of :
Los Angeles Department of Water & Power
Northwest Hydraulic Consultants
** Models Run at Same Flow Rate **
7/31/2019 RedValve - Mixing in Storage Tanks
14/49
Mixing Time Equation is Limited to Same
Inlet and Tank Water Temperature
Mixing Time Equat ion MayMixing Time Equat ion MayGrossly Underest imate FillGrossly Underest imate Fill
Time Required t o MixTime Required t o Mix Jet Must Reach Water Sur faceJet Must Reach Water Sur face
to Mix Tankto Mix Tank
Mixing Will Only Occur t oMixing Wi ll Only Occur t oTerm inal Rise Height (TRH) ofTerm inal Rise Height (TRH) ofJetJet
Below TRHBelow TRH -- Adequate Mixing,Adequate Mixing,Temperature, and ResidualTemperature, and Residual
Above TRHAbove TRH No Mixing, WaterNo Mixing, Wat er
Age Cont inually I ncreases Wit hAge Cont inually I ncreases Wit hEach Fil l & Draw Cycle, LoseEach Fil l & Draw Cycle, LoseResidualResidual
Have No I dea of Potent ialHave No I dea of Potent ialProblem Even if SamplingProblem Even if Sampling
Out side of TankOut side of Tank
2oF Colder Inlet Water
7/31/2019 RedValve - Mixing in Storage Tanks
15/49
Effect Of Colder I nlet Water on Mix ing in Reservoir
INLET 4INLET 4F COLDERF COLDER
WillWill ShortShort --Circuit Even w it hCircuit Even w it h
Separate Out let PipeSeparate Out let Pipe
Will NotWill Not Mix Tank RegardlessMix Tank Regardless
How Long it is FilledHow Long it is Filled
ISOTHERMALISOTHERMAL
Will NotWill Not ShortShort --Circuit w it hCircuit w it hSeparate Out let PipeSeparate Out let Pipe
WillWill Mix TankMix Tank I FI F Fil l LongFil l Long
EnoughEnough
CFD Model 2.5MG Reservoir (120 Dia. X 30 SWD)
7/31/2019 RedValve - Mixing in Storage Tanks
16/49
Effect Of Colder I nlet Water on Mix ing in Reservoir
I nlet Riser St il l Result s inI ncomplete Mixing and St rat if icat ion
7/31/2019 RedValve - Mixing in Storage Tanks
17/49
A Single I nlet Pipe Often Cannot Mix a Tank
in Summer w ith Colder I nlet Water
Properly Designed Mult i-PortManifolds Can Complet ely
Mix in Summer
7/31/2019 RedValve - Mixing in Storage Tanks
18/49
TTHM, HAA5,Temperature and ClTTHM, HAA5,Temperature and Cl22 Residual DataResidual Data
1.5MG Standpipe1.5MG Standpipe Champlain W.D., VTChamplain W.D., VTDangerously close to
Stage II MCL of 80 ppb
7/31/2019 RedValve - Mixing in Storage Tanks
19/49
Guidelines of Water Turnover RateGuidelines of Water Turnover Rate
7/31/2019 RedValve - Mixing in Storage Tanks
20/49
Achieve Adequate
Turnover
Fluctuat e Tank Levels t oMinimize Volume-BasedWater Age. (20-30% commongoal). Amount will vary bysystem conditions.
Elim inate Localized I ncreasein Water Age by Designing
Mixing Syst em for CompleteMix ing Based on Amount ofDaily Tank Fluctuat ion.
Must Account forTemperature Differences -
so be Conservat ive
Spat ial Sampling (Residualand Temperat ure)Recommended
7/31/2019 RedValve - Mixing in Storage Tanks
21/49
PROBLEMPROBLEM
TIDEFLEXTIDEFLEX DuckbillDuckbill Check ValvesCheck Valves
SOLUTIONSOLUTION
Overflow Pipe ProtectionOverflow Pipe ProtectionOverflow SecurityOverflow Security
Valve (OSV)Valve (OSV)
7/31/2019 RedValve - Mixing in Storage Tanks
22/49
PROBLEMPROBLEM
TIDEFLEX Research & DevelopmentTIDEFLEX Research & Development
FINITE ELEMENT ANALYSIS (FEA)FINITE ELEMENT ANALYSIS (FEA)
INDEPENDENT HYDRAULIC TESTINGINDEPENDENT HYDRAULIC TESTING
OVER 50 VARIATIONS IN GEOMETRY ANDOVER 50 VARIATIONS IN GEOMETRY AND
STIFFNESSSTIFFNESS PER SIZEPER SIZE FOR HYDRAULICFOR HYDRAULIC
OPTIMIZATION OF TMSOPTIMIZATION OF TMS
7/31/2019 RedValve - Mixing in Storage Tanks
23/49
OUTLETSOUTLETS
Use of Tideflex for Inlet/Outlet Separation
INLETSINLETS
INLETSINLETS
OUTLETSOUTLETS
7/31/2019 RedValve - Mixing in Storage Tanks
24/49
136136 Dia. X 28Dia. X 28 DeepDeep
Circular Steel TankCircular Steel Tank
Typical TMS for Circular Reservoir
(2) 16(2) 16 Series 37 OutletsSeries 37 Outlets
7/31/2019 RedValve - Mixing in Storage Tanks
25/49
CFD Model of 1MG Reservoir(Simulated Tracer Distribution)
7/31/2019 RedValve - Mixing in Storage Tanks
26/49
TMS in Operation During Initial Fill
7/31/2019 RedValve - Mixing in Storage Tanks
27/49
Optimized Hydraulics of Tideflex
Tideflex Inlet Nozzles Maximize Jet
Velocity at ALL Flow Rates
Compared to Fixed-Diameter Pipe
7/31/2019 RedValve - Mixing in Storage Tanks
28/49
TMS Manifold Hydraulics Modeling
Hydraulics account for all pipe, fittings, valves
Use hydraulic data in Mixing Analysis model
Iterate quantity, size, and stiffness of Tideflex
Nozzles until complete mixing is achieved based
on tank turnover
7/31/2019 RedValve - Mixing in Storage Tanks
29/49
7/31/2019 RedValve - Mixing in Storage Tanks
30/49
7/31/2019 RedValve - Mixing in Storage Tanks
31/49
Preventing Water Stagnation in Storage TanksPreventing Water Stagnation in Storage Tanks
Reservoir Case StudyReservoir Case Study
Eugene Water & Electric BoardEugene Water & Electric Board
Brown & Caldwell EngineeringBrown & Caldwell Engineering
7/31/2019 RedValve - Mixing in Storage Tanks
32/49
Chlorine Residuals are Consistent Throughout TankChlorine Residuals are Consistent Throughout Tank
Slide Courtesy of Brown & Caldwell and EWEB
7/31/2019 RedValve - Mixing in Storage Tanks
33/49
Installation/Maintenance/OperationalInstallation/Maintenance/OperationalConsiderations:Considerations:
External Energy SourceExternal Energy Source
Capital CostCapital Cost
Operational CostOperational Cost
No Impact on Water AgeNo Impact on Water Age No Separation of Inlet/OutletNo Separation of Inlet/Outlet
Safety? Electric & WaterSafety? Electric & Water
MaintenanceMaintenance
Roof ReinforcementRoof Reinforcement ReqReqdd
Another Penetration for WiresAnother Penetration for Wires Interfere withInterfere with CathodicCathodic ProtectionProtection
Contamination?Contamination?
VandalismVandalism
NSF Certified?NSF Certified?
Limited InstallationsLimited Installations Limited Testing and Field ValidationLimited Testing and Field Validation
Mechanical Mixers (Electric and Solar Powered)Mechanical Mixers (Electric and Solar Powered)
What any mechanical mixer does is add anothersource of energy to the tank to mix. However,
there is already a built-in source of energy
differential pressure. Tanks need to fill and draw
(exchange water) to minimize water age. That
differential pressure can mix the tank with aproperly designed passive mixing system.
7/31/2019 RedValve - Mixing in Storage Tanks
34/49
Typical TMS for Rectangular ReservoirsTypical TMS for Rectangular Reservoirs
El t d St T kEl t d St T k
7/31/2019 RedValve - Mixing in Storage Tanks
35/49
Wet RiserWet Riser
InletInlet
Dry RiserDry Riser
InletInlet
Elevated Storage TanksElevated Storage Tanks
TMS fTMS f P d hP d h H d illH d ill d C id C it
7/31/2019 RedValve - Mixing in Storage Tanks
36/49
TMS forTMS for PedespherePedesphere,, HydropillarHydropillar and Compositeand Composite
Elevated TanksElevated Tanks
Tideflex Inlet NozzlesTideflex Inlet Nozzles
Waterflex Outlet ValvesWaterflex Outlet Valves
CFD M d lCFD M d l El t dEl t d H d illH d ill
7/31/2019 RedValve - Mixing in Storage Tanks
37/49
CFD ModelCFD ModelElevatedElevated HydropillarHydropillar
Two Inlet Valves at Two Elevations (Four Total)Two Inlet Valves at Two Elevations (Four Total)
l d l d kS li 1 5MG d 2MG El d T k
7/31/2019 RedValve - Mixing in Storage Tanks
38/49
Sampling 1.5MG and 2MG Elevated TanksSampling 1.5MG and 2MG Elevated Tanks
with and without TMSwith and without TMS -- McKinney, TXMcKinney, TX
2MG CompositeElevated with TMS
2MG Composite
Elevated with TMS
1.5MG Composite
Elevated without TMS
7/31/2019 RedValve - Mixing in Storage Tanks
39/49
TMS Configuration for Standpipes
7/31/2019 RedValve - Mixing in Storage Tanks
40/49
TMS Configuration for Standpipes
TMS f St d i
7/31/2019 RedValve - Mixing in Storage Tanks
41/49
TMS for StandpipesTIDEFLEX INLETNOZZLES
WATERFLEXOUTLETVALVES
2008 Red Valve Company/Tideflex Technologies. All rights reserved
7/31/2019 RedValve - Mixing in Storage Tanks
42/49
Standpipe CFD ModelStandpipe CFD Model Multiple InletsMultiple Inlets
Isothermal Negatively Buoyant
Temperature Profiling Adjacent Standpipes
7/31/2019 RedValve - Mixing in Storage Tanks
43/49
Temperature Profiling - Adjacent Standpipes
Tideflex MixingTideflex Mixing
SystemSystem
( installed in( installed in
larger tank )larger tank )
Courtesy of:Courtesy of:
7/31/2019 RedValve - Mixing in Storage Tanks
44/49
Waterflex Outlet ValvesWaterflex Outlet Valves
Tideflex Inlet NozzlesTideflex Inlet Nozzles
7/31/2019 RedValve - Mixing in Storage Tanks
45/49
Temperature vs. DepthTemperature vs. Depth
7/12/03
60
62
64
66
68
70
72
74
76
10 30 50 70 90
0.5 MG 1.5 MG
8/1/03
60
62
64
66
68
70
72
74
76
10 30 50 70 90
0.5 MG 1.5 MG
Without TMS
Without TMS
With TMS With TMS
ICING Case Study (Before Mixing System)
7/31/2019 RedValve - Mixing in Storage Tanks
46/49
ICING Case Study (Before Mixing System)Region of Peel 0.55MG Standpipe (30 Dia. X 110.5)
Ice removal took 2 weeks and $27,000
ICING Case Study (After Mixing System)
7/31/2019 RedValve - Mixing in Storage Tanks
47/49
ICING Case Study (After Mixing System)Region of Peel 0.55MG Standpipe (30 Dia. X 110.5)
Complete System Design and
7/31/2019 RedValve - Mixing in Storage Tanks
48/49
Co p ete Syste es g a dHydraulic Analysis
7/31/2019 RedValve - Mixing in Storage Tanks
49/49
QUESTIONS ?QUESTIONS ?Mike Duer, P.E., Chief Engineer
412-279-0044 phone
Aut hor ized Represent at iveNew England Environment al Equipm ent (NE3)(781) 275-1001 phone
* * Exhibit ing at Conference * *