Document 99qG0QJRm54oQd6gmpx78r3eL

Heating Ventilating Air Conditioning Guide 1939 Table 5. Properties of Monofluorotrichloromethanb (Fu) TSeahtp. . F AB8. Press. La FEB 8q 1m. Volume . liquid Vapor Heat Content and Entropy Taken From -40 F Heat Content Entropy 25 F Superheat 50 F Superheat liquid Vapor liquid Vapor HL CL Entropy Ht CL Entropy 0 2.59 0.01020 13.700 7.81 90.4 0.0178 0.1975 93.9 0.2049 .97.4 0.2120 5 2.96 0.01024 12.100 8.81 91.2 0.0200 0.1974 94.7 0.2047 98.2 0.2117 10 3.38 0.01028 10.700 9.82 92.0 0.0222 0.1973 95.5 0.2045 99.0 0.2114 15 3.85 0.01032 9.530 10.80 92.8 0.0243 0.1971 96.3 0.2043 99.8 0.2111 20 4.36 0.01036 8.490 11.90 93.7 0.0264 0.1970 97.2 0.2041 100.7 0.2109 25 4.94 0.01040 7.580 12.90 94.5 0.0286 0.1969 98.0 0.2039, 101.5 0.2107 30 5.57 0.01045 6.770 13.90 95.3 0.0307 0.1969 98.8 0.2038 102.3 0.2105 35 6.27 0.01049 6.080 14.90 96.1 0.0328 0.1968 99.6 0.2037 103.1 0.2103 40 7.03 0.01053 5.460 16.00 96.8 0.0349 0.1968 100.3 0.2036 103.8 0.2101 45 7.88 0.01057 4.920 17.00 97.6 0.0370 0.1967 101.1 0.2035 104.6 0.2099 50 8.79 0.01062 4.440 18.10 98.4 0.0391 0.1967 101.9 0.2034 105.4 0.2098 55 9.80 0.01066 4.020 19.10 99.2 0.0412 0.1967 102.7 0.2033 106.2 0.2097 60 10.90 0.01071 3.640 20.20 100.0 0.0432 0.1967 103.5 0.2033 107.0 0.2096 65 12.10 0.01076 3.300 21.30 100.8 0.0453 0.1967 104.3 0.2032 107.8 0.2094 70 13.40 0.01081 3.000 22.40 101.5 0.0471 0.1967 105.0 0.2032 108.5 0.2093 75 14.80 0.01086 2.740 23.50 102.2 0.0493 0.1967 105.7 0.2031 109.2 0.2092 80 16.30 0.01091 2.500 24.50 102.9 0.0513 0.1966 106.4 0.2030 109.9 0.2090 85 17.90 0.01096 2.280 25.60 103.6 0.0533 0.1966 107.1 0.2029 110.6 0.2089 90 19.70 0.01101 2.090 26.70 104.4 0.0553 0.1966 107.9 0.2028 111.4 0.2088 95 21.60 0.01106 1.918 27.80 105.1 0.0573 0.1966 108.6 0.2028 112.1 0.2087 100 23.60 0.01111 1.761 28.90 105.7 0.0593 0.1965 109.2 0.2027 112.7 0.2085 10S 25.90 0.01116 1.620 30.10 106.4 0.0613 0.1965 109.9 0.2026 113.4 0.2084 AIR DRYING AGENTS Moisture may be removed from air, thus accomplishing dehumidi fication, by the use of any one of a number of substances if the moist air and these substances are brought together under suitable circumstances. One class of these substances are solids at ordinary conditions and have the power of adsorbing the moisture from the air. Another class of air drying agents are liquids under ordinary conditions and absorb the mois ture from the air. Nearly all the drying agents in frequent commercial use in air conditioning installations are of one or the other of these two classes. Adsorbents \ These substances are characterized by a physical structure containing ' a great number of extremely small pores but still retaining sufficient mechanical strength to resist whatever wear and handling to which they are subjected. To be suitable for air drying purposes they must be widely available at economical cost, durable in use, stable in form and properties, and capable of withstanding the re-activation processes by which they are made ready for repeated use. They must also possess capacity for adsorbing and holding so sufficient a quantity of moisture that the dimensions of the beds necessary to accommodate them will be practical. Aluminum Oxide, (Alumina), in a porous, amorphous form is a solid adsorbent frequently called by the common name activated alumina, and containing small amounts of hydrated aluminum oxide, and very small amounts of soda, and various metallic oxides. A good grade of activated 40 Chapter 2. Refrigerants and Air Drying Agents alumina will show 92 per cent of Ak03, and its soda content will be com bined with silica and alumina into an insoluble compound. This substance also has the property of adsorbing certain gases and certain vapors other than water vapor--a property which is sometimes useful in air condi tioning installations. It is available commercially in granules ranging from a fine powder to pieces approximately 1.5 in. in diameter. It has high adsorptive capacity per unit of weight, and is non-toxic. It may be repeatedly re-activated after becoming saturated with adsorbed moisture without practical loss of its adsorptive ability. In the grade frequently used for air drying the re-activation may be accomplished at temperatures under 350 F. Specific gravity is 3.25 and the pores are reported to occupy 58 per cent of the volume of each particle. For most estimating purposes the volume-weight relation on a dry basis may be taken as 50 lb per cubic foot although in the smaller sizes the packed weight may be as much as 64 lb per cubic foot. Silicon Dioxide, (Silica), in a special form obtained by suitably mixing sulphuric acid with sodium silicate, is another solid adsorbent and is commonly called silica gel. Its capillary structure is exceedingly small, so small that its exact structure has to be deduced rather than observed. The gel is available commercially in a wide variety of sizes of granules ranging from 4 to 300 mesh. It has high adsorptive capacity per unit of weight and is non-toxic, may be repeatedly re-activated without practical deterioration. Re-activation may be accomplished at tem peratures of air up to 600 F although it is frequently accomplished with air or other gases at temperatures not over 350 F. Volume of the capillary pores is reported to be from 50 to 70 per cent of the total solid volume. For most estimating purposes the volume-weight relation can be assumed as from 38 to 40 lb per cubic foot on a dry basis. Other substances having properties which make them available as Table 6. Properties of Water Sat. Temp. F Ann. Lb per Sq In. Liquid Vapor Heat Content and Entbopt Taken Feom +-32 F Heat Couteat Entropy Liquid I Vapor J Liquid I Vapor 50 F Superheat 100 F Superheat HL CL I Entropy HL CL Entropy . ,32 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 10.0887, 0.01602 3296.0 0.10001 0.01602 0.1217, 0.01602 2941.0 2441.0 0.1475i 0.016021 2034.0 0.1780 0.01602 1702.0 0.21401 0.01603 1430.0 0.2561, 0.01603. 1206.0 0.3054 0.016041 1021.0 0.3628| 0.01605 868.0 0.42951 0.01606 740.0 0.507 0.01607, 632.9 0.596 0.698 0.016091 0.01610; 543.3 467.9 0.815 (0.949 1.101 0.01612 0.01613; 0.016151 404.2 350.3 304.4 0.00 1073 .0 0 0000 2.1826 |l096.9 3.02 1074 .4 0.0062 8.05 1076 8 0.0163 13.07 1079 .2 0.0262 1724!11098.3 .1555 ,1100.6, .1390 1102.9 18.08 1081 0.0361 .1230 1105.2 23.08 1083 28.08 1086 33.08 1088 38.07 1090 43.06 1093 48.05 1095. 53.04 1097. 58.03 1100. 63.01 1102. 68.00 1104. 72.98 1106. 0.0459, .1073 1107.5 0.05561 0920i 1109.81 0.0652 0771 1112.2 0.0746 0625 1114.5 0.0840, 0483 (1116-7 0.0933 0344 1119.0 0.1025| .02081 1121.21 0.1116 0075 11123.4 0.1206; 9946 1125.6! 0.1296 9819 1127.9 0.1384 9695 1130.2 .2277, 1120.8112.2688 .2172 1122.2 2.2581 .20001 1124.51|2.2406 1832| 1126.7 12.2234 .1667; 1129.01|2.2066 1506| 1131.3112.1902 1349 1133.5 2.1742 1196 1135.81 2.1585 1046 1138.1 2.1432 0900 1140.3,'2.1283 0758 1142.5|(2.1138 0619 1144.7, 2.0996 0483 1146-81'2.0857 0350 1148.9]12.0721 0220 1151.1 2.0588 0093 1153.2 2.0458 For Properties of steam at high temperatures, see Page 29. 41