Document qRj43380VbL14mVKXzrEvQ0M

American Society of Heating and Ventilating Engineers Guide, 1937 Table 8. Properties of Saturated Steam : Pressure Table--(Concluded) Aba. Preu, Lb./Sq. In.* P 250.0 260.0 270.0 280.0 290.0 Tamp. Deg. F. 404.43 407.79 411.06 414.24 300.0 320.0 340.0 360.0 380.0 41733 42339 428.96 43439 439.59 400.0 420.0 440.0 460.0 480.0 444.58 44938 454.01 458.48 462.80 600.0 620.0 640.0 660.0 680.0 466.99 471.05 474.99 47832 48235 600.0 620.0 640.0 660.0 660.0 486.17 489.71 493.16 496.53 499.82 700.0 720.0 740.0 760.0 780.0 503.04 506.19 50938 51230 51537 600.0 820.0 840.0 860.0 880.0 518.18 521.03 523.83 526.58 529.29 000.0 920.0 940.0 960.0 980.0 531.95 53436 537.13 539.66 542.14 1000.0 1060.0 noo.o 1160.0 1200.0 544.58 55033 5563$ 561.81 S67.14 1260.0 1300.0 1360.0 1400.0 1460.0 57230 57732 582.21 586.96 59138 1600.0 1600.0 1700.0 1800.0 1900.0 596.08 604.74 612.98 620.86 62839 2000.0 2200.0 2400.0 2600.0 2800.0 635:6 6493 661.9 673.8 684.9 3000.0 3200.0 3226.0 69S3 704.9 706.1 Specific Volume Sat. Sat. Liquid Evap. Vapor f Vfc Vg 0.01867 1.8223 1.8410 0.01872 1.7536 1.7723 0.01877 1.6895 1.7083 0.01882 1.6302 1.6490 0.01887 1.5745 1.5934 0.01892 1.5225 1.5414 0.01901 1.4279 1.4469 0.01910 1.3439 13630 0.01918 1.2689 13881 0.01927 13015 13208 0.0194 0.0194 0.0195 0.0196 0.0197 1.1407 1.1601 1.0853 1.1047 1.0345 1.0540 0.9881 1.0077 0.9456 0.9633 0.0198 0.0198 0.0199 0.0200 0.0201 0.9063 0.9261 0.8701 0.8899 0.8363 0.8562 0.8047 03247 0.7751 0.7952 0.0202 0.0202 0.0203 0.0204 0.0205 0.7475 0.7677 0.7217 0.7419 0.6972 0.7175 0.6744 0.6948 0.6527 0.6732 0.0206 0.0206 0.0207 0.0208 0.0209 0.6321 0.6527 0.6128 0.6334 03944 0.6151 03769 0.5977 03602 03811 0.0209 0.0210 0.0211 0.0212 0.0213 0.5444 0.56S3 03293 03503 03149 0.5360 03013 0.5225' 0.4881 03094 0.0213 0.0214 0.0215 0.0216 0.0217 0.4756 0.4969 0.4635 0.4849 0.4520 0.473S 0.4409 0.4625 0.4303 0.4520 0.0217 0.0219 0.0222 0.0224 0.0226 0.4202 0.4419 03960 0.4179 03738 03960 03540 03764 03356 03582 0.0228 0.0230 0.0232 0.0235 0.0237 03187 03415 03029 03259 03884 03116 0.2748 0.2983 03621 0.2858 0.0239 0.0244 0.0249 0.0254 0.0260 03502 03741 03284 03528 03089 0.2338 0.1913 03167 0.1754 03014 0.0265 0.0277 0.0292 0.0310 0.0333 0.1610 0.1875 0.1346 0.1623 0.1112 0.1404 0.0895 0.1205 0.0688 0.1021 0.0367 0.0477 0.0844 0.C459 0.0142 0.0601 0.0522 0 0.0522 Total Heat Sat. Sat. Liquid Evap. Vapor hr hfg hg 376.02 824.5 1200.5 379.78 821.2 1201.0 383.44 818.0 1201.4 387.02 814.7 1201.8 390.50 811.6 1202.1 393.90 808.5 1202.4 400.47 8023'1203.0 406.75 796.6 1203.4 412.80 790.9 1203.7 418.61 7853 1203.9 4243 429.6 434.8 439.9 444.9 779.8 1204,1 7743 1204.1 7693 1204.1 764.1 1204.0 759.0 1203.9 449.7 454.4 459.0 463.6 468.0 754.0 1203.7 749.0 12033 744.1 12033 7393 1202.9 7343 12023 4723 476.6 4803 484.9 488.9 7293 1202.1 725.1 1201.7 7203 12013 715.9 12003 7113 12003 492.9 4963 500.6 504.4 5083 706.8 1199.7 702.4 11993 697.9 1198.6 693.5 1198.0 6893 1197.4 5113 515.5 519.0 522.6 526.0 684.9 1196.7 680.6 1196.0 676.4 1195.4 672.1 1194.7 667.9 11943 529.5 532.9 5363 539.6 542.8 6633 11933 659.7 1192.6 655.6 11913 6513 1191.1 6473 11903 5463 554.0 561.7 5693 5763 6433 1189.6 633.6 1187.6 623.9 1185.6 6143 11833 604.9 1181.4 583.6 590.6 5973 6043 611.0 595.6 11793 5863 1177.0 5773 1174.7 568.1 1172.4 559.1 1170.0 6173 630.2 642.5 654.7 666.8 5503 1167.6 532.6 1162.7 515.0 11573 4973 12513 478.9 1145.7 679.0 703.7 729.4 756.7 786.7 460.0 1139.0 420.0 1123.8 376.4 11053 3273 10843 2723 1058.9 823.1 2023 1025.6 887.0 75.9 962.9 925.0 0 925.0 Entropy Sat. Sat. Liquid Evap. Vapor Sf Sfg Sg 0.5680 0.9581 1.5261 0.5723 0.9504 1.S227 03765 0.9430 1.5194 0.5805 0.9357 1.5163 0.5845 0.9287 1.5132 Aba. Preu. Lb./Sq. In. P 250.0 260.0 270.0 280.0 290.0 03883 0.9220 1.5102 0.5957 0.9089 1.5046 0.6027 03965 1.4992 0.6094 03846 1.4940 0.6157 0.8733 1.4.891 0.6218 0.8625 1.4843 0.6277 0.8S20 1.4798 0.6334 0.8420 1.4753 0.6388 0.8322 1.4711 0.6441 0.8228 1.4670 300.0 320.0 340.0 360.0 380.0 400.0 420.0 440.0 460.0 480.0 0.6493 03137 1.4630 0.6543 0.8048 1.4591 0.6592 0.7962 1.4554 03639 0.7878 1.4517 0.6686 0.7796 1.4482 600.0 620.0 640.0 660.0 680.0 0.6731 0.7716 1.4447 0.677S 0.7638 1.4413 0.6818 0.7562 1.4380 0.6861 0.7487 1.4348 0.6902 0.7414 1.4316 600.0 620.0 640.0 660.0 680.0 0.6943 0.7342 1.4285 0.6983 0.7272 1.4255 0.7022 0.7203 1.4225 0.7060 0.7136 1.4196 0.7098 0.7069 1.4167 7003) 720.0 740.0 760.0 780.0 0.7135 0.7004 1.4139 0.7171 0.6940 1.4111 0.7207 0.6877 1.4084 0.7242 0.6815 1.4057 0.7277 03754 1.4031 800.0 820.0 840.0 860.0 880.0 0.7311 0.6694 1.4005 0.7344 0.6635 13980 0.7377 03577 1.3954 0.7410 03520 13930 0.7442 0.6464 13905 900.0 920.0 940.0 960.0 980.0 ' 0.7473 0.7550 0.7624 0.7695 0.7764 0.6408 0.6273 03141 0.6014 0.5891 13881 13822 13765 13709 13656 1000.0 1060.0 1100.0 - 1160.0 1200.0 ' - 0.7831 0.5772 13603 0.7897 0.5654 13552 0.7962 0.5540 13501 6.8024 03428 13452 03086 03318 13404 1260.0 1300.0 1360.0 UOo!o 1460.0 . 03146 0.5212 13357 0.8262 0.5003 13265 0.8373 0.4801 13174 03482 0.4601 13083 03589 0.4402 13990 1600.0 1600.0 1700.0 1800.0 1900.0 03696 0.4200 13896 03912 03788 13700 0.9133 03356 13488 0.9364 03892 13257 0.9618 03379 1.1996 2000.0 2200.0 2400.0 2600.0 2800.0 0.9922 0.1754 1.1676 3000.0 1.0461 0.0651 1.1112 3200.0 1.0785 0 1.0785 3226.0 . 30 o Chapter 1--Air, Water and Steam responding change in the latent heat of evaporation. These values are given in Table 8. Specific Heat. The specific heat of water, or the amount of heat (Btu) required to raise the temperature of one pound of waterone degree Fahren heit, varies with the temperature, but it is commonly assumed to be unity at all temperatures. Steam tables are based on exact values, however. The specific heat of ice at 32 F is 0.492 Btu per pound. The amount of heat required to raise one pound of water at 32 F through a known temperature interval depends on the average specific heat for the temperature range. Sensible and Latent Heat. The heat necessary to raise the temperature of one pound of water from 32 F to the boiling point is known as the heat of the liquid or sensible heat. When more heat is added, the water begins to evaporate and expand at constant temperature until the water is entirely changed into steam. The heat thus added is known as the latent heat of evaporation. PROPERTIES OF STEAM Steam is water vapor which exists in the vaporous condition because sufficient heat has been added to the water to supply the latent heat of evaporation and change the liquid into vapor. This change in state takes place at a definite and constant temperature which is determined solely by the pressure of the steam. The volume of a pound of steam is the specific volume which decreases as the pressure increases. The reciprocal of this, or the weight of steam per cubic foot, is the density. (See Table 8.) Steam which is in contact with the water from which it was generated is known as saturated steam. If it contains no actual water in the form of mist or priming, it is called dry saturated steam. If this be heated and the pressure maintained the same as when it was vaporized, its temperature will increase and it will become superheated, that is,' its temperature will be higher them that of saturated steam at the same pressure. REFERENCES Rational Psychrometric Formulae, by W. H. Carrier (A.S.M.E. Transactions, Vol. 33, 1911). Temperature of Evaporation, by W. H. Carrier (A.S.H.V.E. Transactions, Vol. 24, 1918). The Evaporation of a Liquid into a Gas, by W. K. Lewis (A.S.M.E. Transactions, Vol. 44, 1922). The Evaporation of a Liquid into a Gas--a Correction, by W. K. Lewis (Mechanical Engineering, September, 1933). Temperature of Evaporation of Water into Air, by W. H. Carrier and D. C. Lindsay (A.S.M.E. Transactions, Vol. 46, 1924). A New Psychrometric Chart, by C. A. Bulkeley (A.S.H.V.E. Transactions, Vol. 32, 1926). A Review of Psychrometric Charts, by C. O. Mackey (Heating and Ventilating, June, July, 1931). Air Conditioning Applied to Cold Storage and a New-Psychrometric Chart, by C. A. Bulkeley (Refrigerating Engineering, February, 1932). The Psychrometric Chart, by E. V. Hill (Aerologist, April, May, June, 1932). Air Conditioning Theory, by John A. Goff (Refrigerating Engineering, January, 1933). 31