Document 6wY2Y2ygYa3zjQ3y6YRrvyQg3

14 CHAPTER 2 - 1953 Guide Thermal conductance per unit area, Unit conductance: heat>transferred per . , (unit time) (unit area) (degree)................ ... ......................... ,CL c _c_ i _ g fe ' * A HA A(l, -- tt) L ' Thermal conductivity: heat transferred per (unit time), (unit area) (degree per unit length)........ ;................................................... . .7.. . ..... .7 .k a k = ---- (fi -- tt) ! . Surface coefficient of heat transfer, Film coefficient of heat transfer, Individual coefficient of heat transfer: heat transferred per (unit time) (unit area) (degree)............................. .......................... ............ ............ '........ ". .7 ...;... .. .. f f= A (l -- k (In general / is not equal to k/L, where L is the actual-thickness of the fluid film.) Overall coefficient of heat transfer. Thermal transmittance per unit area: heat .transferred per (unit time) (unit area) (degree overall) .............................U _ A U= ti -- tt . 'r Thermal transmission (heat transferred per unit-time)................ ..................g . Q Thermal resistance (degree per unit of heat transferred per unit time)............ .. R ft - ^ _ 1* q kA '7 Thermal resistivity__ ___ ,............ ................. ...................................... .....................1/k Vaporization values at constant pressure, Differences between values for satu rated vapor and saturated liquid at the same pressure.................... Subscript fg Velocity..................................................................................................................... ... .. V Viscosity, absolute.................................... ............................ ....................................... p Viscosity, kinematic................................ ................................................... :.......... . V/p Volume (total)............................................................... ................................................ V Volume per unit time, Rate at which quantity of material passes through a machine, Quantity of heat per unit time, Quantity of beat per unit height... Weight of a major item, Total height............................... ....................... Weight rate, Weight per unit of power, Weight per unit of time............ ,----- Work (total)................................ ................ ............ ............. ................................... THE GREEK ALPHABET A a Alpha B P Beta r y Gamma A 5 Delta E t Epsilon Zf. Zeta H v Eta..' e e Theta I t Iota K k Kappa A A Lambda M fi Mu . N v Nu H.f Xi O o Oinicron II w. Pi P P Rho ,, S <r s Sigma T T Tau T v Upsilon 4> <p <6 Phi Xx Chi Psi . Q to Omega Abbreviations and Symbols - : ..... CONVERSION EQUATIONS5 Heat, Power anti Work 1 ton refrigeration < Latent heat of ice , . 1 Btu 1 Int. watthour I Int. kilowatthour ! 1 Int: kilowatt (1000 watts) 1000 I.T. calories) 1 I.T. Kilocaloriej 1 horsepower I boiler horsepower _ / 12,000 Btu per hour 200 Btu per minute = 143.4 Btu per pound 778.3 ft-lb 0.2930 Int. whr 252.0 I.T. calorie ( 2656 ft-lb' = 1 3.413 Btu ] 3600 Int. joules. 7 l 860 I.T. calories ........ ( 3,413 Btu = ( 3.517 lb water evaporated from ( and at 212 F. , 1.341 hp 56.88 Btu per minute. 7 \ 44,267 ft-lb per minute 3.968 Btu 3088 ft-lb 1.1628 Int. whr ( 0.7455 Int. kw _ I 42.40 Btu per minute _ 1 33,000 ft-lb per minute ( 550 ft-lb per second _ ( 33,475 Btu per hour ~ \ 9.809 Int. kw Weight and Volume 1 gal (U. S.) 1 British or Imperial gallon' 1 cu ft 1 cu ft water at 60 F (in vacuo) 1 cu ft water at 212 F (" " ) 1 gal water at 60 F (" " ) 1 gal water at 212 F (" " ) 1 lb (avdp) 1 bushel 1 short ton Pressure 1 lb per square inch _ j 231 cu in. "\ 0.1337 cu ft 277.42 cu in. ( 7.481 gal \ 1728 cu in. = 62.37 lb = 59.83 lb = 8.338 lb = 7.998 lb _ / 16 oz ~ \ 7000 grains = 1.244 cu ft = 2000 lb 144 lb 2.0360 per square foot 1 in. mercury at 32 F 2.0422 in. mercury at 62 F 9. SOQ ft water at 62 F 1 oz per square inch 0.1276 in. mercury at 62 F 1.732 in. water at 62 F ' Abbreviations 1nl. and I.T. nttt to International `Checked in 1944 by National Bureau aj`Standards. and International (Stem) Table, respectively.: