COIL CONSTRUCTION
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COIL
CONSISTS OF TUBES AND EXTERNAL FINS ARRANGED
IN ROWS ALONG,THE AIR FLOW TO PROVIDE GREATER SURFACE AREA.
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WATER
/ REFRIGERANT FLOWS INSIDE TUBES, WHlLE
AIR FLOWS OVER EXTERNAL SURFACE.
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TO
MAINTAIN HIGH RATE OF HEAT
TRANSFER, AIR AND WATER FOLLOW A
COUNTER FLOW ARRANGEMENT
i.e COLDEST AIR MEETS COLDEST WATER AND
WARMEST AIR MEETS WARMEST WATER.
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STRUCTURAL
FRAME WORK END PLATE : GALVANISED STEEL SHEET.
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HEADER
IS OF COPPER
A)TUBES MATERIAL
:
MOSTLY COPPER
: IN
SOME APPLICATIONS, (PETROCHEMICALS ETC) ALUMINIUM TUBES ARE USED, AS AMMONIA
REACTS WITH COPPER
B)TUBE DIAMETER
C)PITCH
: LONGITUDINAL, TRANSVERSE - 25 TO 40 mm
D)FINS
: ARE ALUMINIUM PLATE CORRUGATED/ RIPPLED FINS PROVIDE HIGH HEAT TRANSFFR
MOST
COMMON
COPPER TUBE :(1/2"
OD, 27 G THICKNESS – BSL) WITH ALUMINIUM FINS - 0.16 MM THICK
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TO ARREST DIELECTRIC CORROSSION, ONE CAN HAVE COPPERR TUBES
WITH COPPER FINS. IT IS VERY EXPENSIVE AND SELDOM USED.
ROWS DEEP: CAN BE 2,4,6,8
FIN SPACING: CAN
BE 8, 10, 12 FINS PER INCH
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HIGHER THE FINS, BETTER THE HEAT TRANSFER. HOWEVER, AIR
PRESSURE DROP IS ALSO HIGH.
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LESSER FPI OF SHOULD
BE USED FOR LOW TEMP JOBS. Etc PROBLEMS OF FROST POSSIBILITY OF LINT
ACCUMULATION, OR CHOKING.
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