இடுகைகள்
HEAT EXCHANGER
CONVENTIONAL TUBULER HEAT EXCHANGER CONT”d
Some OF the more common tybular heat exchanger are
1. U tube heat exchanger
2. Floating head heat exchanger pull through type
3. Floating head heat exchanger lantern head type
4. Floating head heat exchanger split backing ring type
5. Kettle type reboiller
Why do we use heat exchanger?
To exchange heat between two fluids
Type of heat transfer equipment
Cooler cools using water or air without phase change
Chiller refrigerates below that obtainable with water
Condenser condenses vapour/ vapour mixture
Steam heater uses seam from team for heating
Steam generator produces steam from water
Reboiler uses steam /hot fluid to heat,for distillation column
Types of shell and tupe heat exchanger
1.floating head exchanger
Permits free expansion/contraction
Eacy to clean
2.fixed tubesheet exchanger
If shell side fouling , notsuitable
Cheapest and most economical
3. u tube exchanger
Tube expansion independent of other tubes
Tubes difficult to clean internally
4.reboiler/kettle type exchanger
Can handle large fluctuating loads
HEATCXCHANGER FAILURES
WHAT IS FAILURE?
FAILURE TO DELIVER THE FUNCTION WITCH IT IS INTENDED TO PERFOM
WHAT ARE THE TYPES OF HEAT EXCHANGER?
1. CORROSION
2. MECHNICAL
3. PROCESS RELATED
CORROSION
UNIFORM ATTACK
UNIFORM THINNING
STRESS CORROSION CRACKING
SUSCEPTIBLE MATERIAL AND CORRODING ENVIRONMENT
PITTING
LOCALISED ATTACK IN THE FORM OF PITS
UNDER DEPOSIT CORROSION { E.G . LOW VELOCITY AREAS}
MECHANICAL
VIBRATION
TUBE TO TUBESHEET JOINT LEAK
BAFFILE HOLE GROOVING INTO TUBE EXTERNAL SURFACE
LOOSENING OF GASKET BOLTHING
WEAR DUE COLLISION OF TUBE TO TUBE
VELOCITY
EROSION OF TUBES AT ENTRY SIDE , INTERNALLY {TUBE SIDE}
EROSION OF TUBES ON OUTSIDE SURFACE {SHELL SIDE}
EROSION OF INLET/OUTLET NOZZLES
EROSION AT BAFFLE HOLE TO TUBE INTERFACE
FAILURES……
TUBE LEAK
TUBE TO TUBESHEET JOINT LEAK
GASKET LEAK{SHELL\TS OR TS\CHANNEL OR FLOATING HEAD}
CORRODED THINNED DOWN SHELL\SHELL\TUBESHEET}
REPAIRS CARRIED OUT VIDE………
. MAINTENANCE PROCEDURES {PLUGGING\WELDING\ EXPANSION}
. REPLACEMENT WITH EXISTING METALLURGY WITH…..
. PROPOSE CHANGE IN OPRATING CONDITIONS
. DESIGN CHANG
. ACCEPT DEGRADATION RATE {BASED ON ECONOMY}
. UPGRADATION IN METALLURGY
GASKET LEAK
DAMAGED GASKET
PROPER GASKET WITH STANDARD INSTALLATION AND TIGHTENING PROCEDURES
DAMAGED GASKET SEATING FACES
RESTORE THE GASKET SEATING FACES WITH WELD-OVERLAY FOLLOWED BY RESTORING REQUISITE SURFACE ROUGHNESS
TUBE LEAK
.CUTTING OF LEAKY TUBE FOR INVESTIGATION
. PLUGGING THE LEAKY TUBES
.COMMON TAPER-PLUGS USED
. J-PLUG WELDED
TUBE TO TUBESHEET JOINT LEAK
ROLL EXPANDED
.RE-ROLLING, IF EXPANSION LIMITS NOT EXCEEDED
. DRILLING OUT OLD TUBE ,REINSERTING NEW TUBE AND EXPANSION
.IF GROOVE DAMAGED, PLUG THE TUBE
SEAL-WELDED
.GRIND UPTO ROOT
. RE-WELD USING SUITABLE FILLER WIRE
. ROLL EXPAND, LEAVING 10mm FROM FRONT TUBESHEET
MATERIALS OF CONSTRUCTION
SHELLL\CHANNEL\SHELL COVER
CS, ALLOY STEEL, CORROSION RESISTANT CLAD STEEL
TUBES
CS, ALLOY STEEL, SS, NON FERROUS
BAFFLES
CS GENERALLY
TUBESHEETS
CS, ALLOY STEEL CORROSION RESISTANT CLAD STEEL, CUPRONICKEL, SS
CONVENTIONAL TUBULER HEAT EXCHANGER CONT”d
Some OF the more common tybular heat exchanger are
1. U tube heat exchanger
2. Floating head heat exchanger pull through type
3. Floating head heat exchanger lantern head type
4. Floating head heat exchanger split backing ring type
5. Kettle type reboiller
Why do we use heat exchanger?
To exchange heat between two fluids
Type of heat transfer equipment
Cooler cools using water or air without phase change
Chiller refrigerates below that obtainable with water
Condenser condenses vapour/ vapour mixture
Steam heater uses seam from team for heating
Steam generator produces steam from water
Reboiler uses steam /hot fluid to heat,for distillation column
Types of shell and tupe heat exchanger
1.floating head exchanger
Permits free expansion/contraction
Eacy to clean
2.fixed tubesheet exchanger
If shell side fouling , notsuitable
Cheapest and most economical
3. u tube exchanger
Tube expansion independent of other tubes
Tubes difficult to clean internally
4.reboiler/kettle type exchanger
Can handle large fluctuating loads
HEATCXCHANGER FAILURES
WHAT IS FAILURE?
FAILURE TO DELIVER THE FUNCTION WITCH IT IS INTENDED TO PERFOM
WHAT ARE THE TYPES OF HEAT EXCHANGER?
1. CORROSION
2. MECHNICAL
3. PROCESS RELATED
CORROSION
UNIFORM ATTACK
UNIFORM THINNING
STRESS CORROSION CRACKING
SUSCEPTIBLE MATERIAL AND CORRODING ENVIRONMENT
PITTING
LOCALISED ATTACK IN THE FORM OF PITS
UNDER DEPOSIT CORROSION { E.G . LOW VELOCITY AREAS}
MECHANICAL
VIBRATION
TUBE TO TUBESHEET JOINT LEAK
BAFFILE HOLE GROOVING INTO TUBE EXTERNAL SURFACE
LOOSENING OF GASKET BOLTHING
WEAR DUE COLLISION OF TUBE TO TUBE
VELOCITY
EROSION OF TUBES AT ENTRY SIDE , INTERNALLY {TUBE SIDE}
EROSION OF TUBES ON OUTSIDE SURFACE {SHELL SIDE}
EROSION OF INLET/OUTLET NOZZLES
EROSION AT BAFFLE HOLE TO TUBE INTERFACE
FAILURES……
TUBE LEAK
TUBE TO TUBESHEET JOINT LEAK
GASKET LEAK{SHELL\TS OR TS\CHANNEL OR FLOATING HEAD}
CORRODED THINNED DOWN SHELL\SHELL\TUBESHEET}
REPAIRS CARRIED OUT VIDE………
. MAINTENANCE PROCEDURES {PLUGGING\WELDING\ EXPANSION}
. REPLACEMENT WITH EXISTING METALLURGY WITH…..
. PROPOSE CHANGE IN OPRATING CONDITIONS
. DESIGN CHANG
. ACCEPT DEGRADATION RATE {BASED ON ECONOMY}
. UPGRADATION IN METALLURGY
GASKET LEAK
DAMAGED GASKET
PROPER GASKET WITH STANDARD INSTALLATION AND TIGHTENING PROCEDURES
DAMAGED GASKET SEATING FACES
RESTORE THE GASKET SEATING FACES WITH WELD-OVERLAY FOLLOWED BY RESTORING REQUISITE SURFACE ROUGHNESS
TUBE LEAK
.CUTTING OF LEAKY TUBE FOR INVESTIGATION
. PLUGGING THE LEAKY TUBES
.COMMON TAPER-PLUGS USED
. J-PLUG WELDED
TUBE TO TUBESHEET JOINT LEAK
ROLL EXPANDED
.RE-ROLLING, IF EXPANSION LIMITS NOT EXCEEDED
. DRILLING OUT OLD TUBE ,REINSERTING NEW TUBE AND EXPANSION
.IF GROOVE DAMAGED, PLUG THE TUBE
SEAL-WELDED
.GRIND UPTO ROOT
. RE-WELD USING SUITABLE FILLER WIRE
. ROLL EXPAND, LEAVING 10mm FROM FRONT TUBESHEET
MATERIALS OF CONSTRUCTION
SHELLL\CHANNEL\SHELL COVER
CS, ALLOY STEEL, CORROSION RESISTANT CLAD STEEL
TUBES
CS, ALLOY STEEL, SS, NON FERROUS
BAFFLES
CS GENERALLY
TUBESHEETS
CS, ALLOY STEEL CORROSION RESISTANT CLAD STEEL, CUPRONICKEL, SS
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