redvalve - mixing in storage tanks

Upload: rwbalmelo

Post on 05-Apr-2018

222 views

Category:

Documents


0 download

TRANSCRIPT

  • 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

    [email protected]

    Aut hor ized Represent at iveNew England Environment al Equipm ent (NE3)(781) 275-1001 phone

    * * Exhibit ing at Conference * *