2 Power Pres
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Transcript of 2 Power Pres
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8/11/2019 2 Power Pres
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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