Monday, July 26, 2010

Selected Conversion Factors Frequently Used in Design Calculations

Hi Friends,

We all are well aware about many conversion factors, but the major ones are listed below just to brush up our memory as ready reference-

Length:
1 meter = 3.281 ft.
1 meter= 1.096 yards
1 km = 0.621 mile
1 mm = 1000 micron

Area:
1 sq.km=247.104 Acres
1 sq.km=100 Hectares
1 Hectare=10000 sq.m
1 Hectare=2.47 Acres

Volume:
1 cub.m= 1000 Litres
1 cub.m=35.315 cub.ft.
1 UK Gallon=4.546 Litres
1 US Gallon=3.785 Litres
1 cub.ft.= 28.316 Litres
1 TMC = 6226 million Gallons
1 TMC = 17.1 Million Gallons per Day (MGD).

Density:
1 kg/cub.m=0.001 g/cub.cm
1 kg/cub.m=1000 g/cub.m
1 kg/cub.m=0.062 pound/cub.ft.
1 kg/cub.m=1g/litre.

Flow:
1 cub.ft/hr=7.866 cub.cm/sec
1 gallon/day=3.785 lit/day

Speed:
1 m/sec=3.281 ft/sec
1 m/ sec=3.6 km/hr
1 m/sec/2.237 miles/hr

Acceleration:
1 cm/second square = 0.394 ft/second square.

Energy:
1 calorie = 4.1868 Joules
1 kJ = 0.278 Wh
1 Btu =1055.06 Joules
1 Btu = 252 calories.

Power:
1 kw=1.341 hp
1 kw=0.947 Btu/sec
1 kw=239.057 cal/sec
1 kw=102 kg.m/sec
1 kw=860 kcal/hr.

Mass:
1 kg = 2.204 pounds
1 kg = 5000 carates
1 pound = 453.6 grams.

Viscosity:
1 stoke= 0.0001 m2/sec
1 poise = 1 g/cm.sec
1 centi poise= 0.01 poise
1 centi poise =2.42 lb/ft.hr.

Force:
1 Newton = 100,000 dynes
1 Newton = 0.102 kgf.

Pressure:
1 atm = 1.01325 bar
1 atm = 1.033 kg/sq.cm
1 atm = 101325 pascal
1 atm = 76 cm of Hg
1 atm = 100,000 N/sq.m
1 atm = 33.93 ft. water at 60 deg.C
1 psi = 2.309 ft. water at 60 deg.C.

Specific Heat:
1 Btu/lb.deg.F = 1 cal/g.deg.C
1 cal/g.deg.C = 4186.8 J/kg.deg.C
1 Btu/lb.deg.C=2326 J/kg.deg.C
1 cal/g.deg.C=1 kcal/kg.deg.C

Heat Transfer Co-efficient:
1 kcal/hr.sqm.deg.C= 1.163 w/sqm.deg.C
1 kcal/hr.sqm.deg.C=0.205 Btu/sq.ft.sec.deg.C.

Angle:
1 Radian = 57.295 degrees.

Above indicated conversion factors to be always kept in mind while carrying out Material & heat balance, process design and equipment sizing calculations.

Regards.

Rajendra Kunwar

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