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    Solut ions beyond technology

    Theory

    2. Theory

    A lfa Laval

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    Solut ions beyond technology

    TheoryHow does i t work?

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    Solut ions beyond technology

    TheoryConst ruct ion

    Frame Pressure vessel steel, no welds

    Connections In general same material as

    plate or gasket

    Gaskets

    NBR < 110O

    C / 230O

    F EPDM < 165OC (excl. oil)

    Gasket-free > 165OC / 330O F

    Plate selection

    50

    100

    304 316

    SMO

    0

    10 102 103 104 105

    Corrosion.

    Titanium is

    required

    No

    corrosion

    Chloride

    ion

    (ppm)

    Temp. CO

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    Solut ions beyond technology

    Theory

    HE Design

    Considerat ions

    PHE vs.Shell & TubeOperational concernsMaldistributionFoulingCorrosionErosionLeakage

    BypassingVibrationFoulingTensionTorsionShearStress

    PHE vs.Shell & TubeBasic Design concernsDesign temperatureDesign pressureMaterialNozzle size / flowMetal temperaturesBaffle spacingBaffle cutBaffle orientationPress lanesTie rodsDummy tubesSealing stripsExpansion joints

    Tube to tube sheet jointsNozzle locationTube to baffle clearanceBundle to shell clearanceBaffle to shell clearance

    Less design criteria

    provides better & safer

    solutions !

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    Solut ions beyond technology

    TheoryTai lor-made Solu t ions

    H + H = H

    High turbulence

    High pressure drop

    H + L = M

    Medium turbulence

    Medium pressure drop

    L + L = L

    Low turbulence

    Low pressure drop

    High Theta-Channel Low Theta-ChannelMixed Theta-Channel

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    Solut ions beyond technology

    TheoryPressure Drop

    0

    5

    10

    15

    20

    25

    30p per meter

    pipe / channel

    (mwc/m)

    m / s

    Max. velocity in tube m/s:

    AdmiraltyAlu-Brass

    Copper Nickel (90/10)

    Copper Nickel (70/30)

    Titanium

    PHE

    Shell & Tube

    4,5

    4,2

    3,9

    3,6

    3,3

    3,0

    2,7

    2,4

    2,1

    1,8

    1,5

    1,2

    0,9

    0,6

    0,3

    0

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    Solut ions beyond technology

    Theory

    Heat Transfer (K -Value)

    Function of pressure dropper pipe/channel length

    K

    P (log. scale)0

    10 0 0

    20 0 0

    30 0 0

    40 0 0

    50 0 0

    60 0 0

    70 0 080 0 0

    90 0 0

    10 0 0 0

    0,02

    0,15

    0,4

    5

    6

    7

    8

    9

    10

    11

    12

    13

    14

    15

    25

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    Solut ions beyond technology

    TheoryFou l ing Margins

    PHEs require less fouling marginwhen designing

    Alfa Laval

    PHE

    Shell & Tube

    Capacity %

    1 2

    125

    100

    75

    Years

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    Solut ions beyond technology

    TheoryThermal Eff ic iency

    Countercurrent F = 1 ~ ( PHE)

    Cocurrent F < 1

    Crosscurrent F < 1

    Flow

    Heat Transfer Area =

    Heatload

    K x ( LMTD x F )

    LMTDCorrection factor = F

    Shell & Tube mixture

    of above flows F = 0,7 - 0,9

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    Solut ions beyond technology

    TheoryIns tal lat ion Cos ts

    35

    40

    34,5

    30

    Temp. CO

    Countercurrent flow (PHE)

    35

    40

    3

    0

    33

    Cocurrent flow (~S&T)

    Countercurrent flow ->

    Closer temperature approach ->

    Savings on pumps, piping and valves

    2.000 m3/ h

    2.200 m3/ h

    2.000 m3/ h

    3.333 m3/ h

    Temp. CO Temp. CO Temp. CO

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    Solut ions beyond technology

    Theory

    S&T PHE

    K-value index 1 3-4

    Total weight

    Drained 6 1

    Operating 7 1

    Floor area

    Installation 8 1

    + maintenance 9 1

    Fouling margin 25% 5% max

    Price index CC 5 2-4

    Bot tom Line

    Chubu Electric

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    Solut ions beyond technology

    TheorySpecif icat ion fo r PHEs

    FlowratesCentral cooling Cooling water compared to

    FW flow +/-20%

    Oil / Water 2 / 1

    Fouling marginSW/FW 5-10%

    FW/FW 0-5%

    Oil/FW 5%

    Steam 10%

    Other 10%

    Pressure drop

    Liquids 0,2 - 1,2 bar

    Steam max. 20 % of inlet pressure