Document 10rO2J0k0aoYnOMnJ4B03dGba

.428 Chapter 23. 1945 Guide - Table 1. Properties of Lithium Chloride Solutions Concen tration Pound Mols (42.4 Lb) LiCl per 1000 Lb Water Concen tration Per Cent BY Weight Specific; Gravity at 100 F Viscosity (Millipoise) 80 F 180 F Partial Heat of Mixing At OF. Btu per Lb Temp. Coeff. OF Partial Heat of Mixing Btu per Lb per F Specific Heat at 70 F | Boiling Point F at (760 mm Hg) Freezing Point, F 0 2.4 6 8 10 0.0 7.8 14.5 20.2 25.3 29.7 1.000 1.037 1.076 1.111 1.143 1.172 8.61 11.19 14.42 18.62 24.32 32.28 3.48' 4.56 - 6.01 7.78 10.00 12.91 0.00 2.04 7.24 16.70 31.90 51.10 0.000 -0.014 -0.036 -0.069 -0.109 -0.143 0.998 0.901 0.831 0.778 0.739 0.710 212.0 215.8 221.5 228.9 238.1 248.4 '32.0 16.3 - 5.8 -34.2 -69.0 -90.0 12 33.7 1.199 43.45 14 37.4 1.225 60.26 16 40.4 1.248 82.04 18 43.3 : 1.270 113.80 20 46.0 1.291 ' 22 24 26 ` 28 30 32 48.4 50.3 52.4 54.3 56.1 57.5 ` 16.56 21.28 27.10 35.48 46.45 75.70 90.80 124.80 145.00 162.00 -0.160 -0.167 -0.176 -0.186 -0.194 0.687 0.666 0.647 0.631 258.8 268.9 277.9 285.8 293.2 -40.0 1.0 36.5 58.1 86.4 60.67 84.33 171.00 177.00 182.00 191.00 194.00 198.00 -0.200 -0.200 -0.210 -0.210 -0.210 -0.220 300.2 307.0 313.0 318.0 323.0 328.0 133.0 156.0 180.0 190.0 195.0 280.0 Table 2. Dew-Point of Air in Equilibrium with Lithium Chloride Solutions Concentration in Pound Mols (42.4 lb) Lithium Chloride per 1000 lb Water Concentration or Lithium Chloride eoHcj 10 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 24.0 26.0 28.0 30.0 320B15.2 308.7 299.9 2902 279.7 269.4 259.1 5i.:521' 44.1 236.. 130.0223.8 218.62143 2103 300K95.4 289.1 280.5 270.9 260.6 2502 240.! :32.6 225.4 218J '1132053 2003 196.9 1923 280275.6 269.5 261.1 260255.8250.0 241.9 251.7 24121 231.6 232.6 222.7 212.8 222.: 203.! 14.1.021106.7 199.7 1933 187.8 1833 1793 175.2 95.5 188.4 181.7 175.4 170.0 165.6162.0 158.4 240236.0'230.4 2222 2132 2032 194.2 185.0|:177.1 170.0I163.6 157.5 152.2 1483 144.6 1403 2201216.2 210.8 203.2 194.4 184.9 175.5 166.' 58.6:151.6I1453 139.6 134.6 130.7 1273 1243 200196.4 191.2 183.9 175.4 166.1 156.7 148.1 403 133.5 127.3 121.9 117.0 1133 110.1 180176.6 171.6 164.7 156.4 147.3 138.1 129.1 22.1 115.5 109..'41104.2 99.6 96.0 160156.8 152.1 145.4 137.4 128.6 119.7 1113 103.9 97.4 91.6 86.6 82.2 140137.0 132.6 126.1 118.4 109.9 1012 93.1 85.9 79.5 73.8 69.0 1201172 113.0 106.8 99.4 91.1 82.7 74.7 67.8 61.5 56.0 1101072 103.2 972 89.9 81.9 73.5 65.6 58.8 52.6 47.1 100 97.4 93.4 87.5 802 72.7 64.4 56.6 49.8 43.7 383 90 87.5 83.6 77.9 71.C 632 55.2 47.6 40.8 34.8 293 80 77.6 73.8 68.4 61.6 54.C 46.1 38.5 31.8 25.9 20.6 70 67.7 64.C 58.7 52.2 44.8 37.0 29.5 22.9 17.2 12.0 60 57.8 54.3 49.1 42!7 35.5 27.9 20.5 14.0 8.3 40 38.0 34.7 29.5 23.9 16.9 9.6 2.4 -3.9 - 20i 15.1 10.7 5.0 -1.7 -8.7 -15.4 I -4.5 -8.6 -13.9 -20.2 -27.0 -33.3 Dehumidifica tion Table 3. `Density of Lithium Chloride Solutions CONCENTRATION (42.4 lb) IACI pbb 1000 lb Watbb 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 0 1.090 1.124 1.156 1.188 1.217 1.242 Tsmpbraturb Deg F 50 100 150 200 250 1.045 1.085 1.119 1.150 1.181 1.209 1.235 . 1.257 1.279 1.037 1.076 1.111 1.143 1.172 1.199 1.225 1.248 1.270 1.291 1.026 1.064 1.100 1.132 1.162 1.188 1.214 1.236 1:259 1.280 1.310 1.317 1.012 1.052 1.087 1.122 1.152 1.178 1.203 1.226 1.248 1.279 1.289 1.307 1.313 1.338 ' 1.142 1.168 1.192 1.215 1.237 1.568 1.278 1.296 1.312 1.327 1.34 429 300 1.267 1.286 1.302 1.318 1.33 1.35 Example 1. Determine the dew-point, wet-bulb, relative humidity and absolute hu midity of air in equilibrium at 100 F with pure lithium chloride solution of density 1.270. Solution. From Table 1 the concentration of a solution of density 1.270 at 100 F is 18.0 M. From Fig. 2 the dew-point of 18 M lithium chloride at 100 F is 43.7 F. From Table 6, Chapter 1, the partial pressure of water over the solution is 0.2858 in. of He,, and the absolute humidity is 42.00 grains per pound dry air. From the psychrometric chart, the wet-bulb is 66.3 F, and the relative humidity is 15 per cent. Example 2. Determine the boiling point, and freezing point of 18 M lithium chloride solutions. Solution. From Table 1, boiling point (standard) is 285.8 F, freezing point is 58.1 F. Example 8. Calculate the heat of vaporization of 1 lb of water from a large amount of 18 M lithium chloride solution at the boiling point. Solution. The heat of boiling is equal to the heat of mixing plus the heat of boiling pure water at the same temperature. The heat of mixing from Table 1 at 18 M and 285.8 F is 145 -- (0.186 X 285.8) = 92 Btu per pound. The heat of vaporization of water from steam tables at 285.8 F is 920 Btu per pound. .Therefore the heat of vaporiza tion of water from the solution is 920 -f- 92 = 1012 Btu per pound. Example 4. One thousand pounds of air per minute at 100 F dry-bulb with a dewPint, of 70 F and a relative humidity of 39 per cent are passed over 18 M lithium chloride solution. The rate of flow of the solution is 200 gpm and the entering temperature is F. The air leaves the absorber at 85 F dry-bulb and dew-point of 35 F. Calculate (u). the heat to be removed from the lithium chloride solution to maintain these con ditions, and (b) the temperature rise of the solution in passing through the absorber. Solution, (a) The enthalpy of the. entering air at 100 F dry-bulb and 39 per cent relative humidity = h* + v^as - 24.00 + (0.39 X 47.40) - 42.49 Btu per pound (Table 6, Chapter 1). . The relative humidity of the air leaving at 85 F dry-bulb and 35 F dew-point is 16.7 P^r cent (psychrometric chart). Enthalpy of leaving air = 20.39 + (0.167 X 28.85) 25.21 Btu per pound (Table 6, Chapter 1). Heat to be extracted from air = 1000 (42,49 -- 25.21) -- 17,280 Btu per minute. ?eat of mixing = 145 -- (0.186 X 80) = 130 Btu per pound of moisture removed. Table 6, Chapter 1, the moisture removal per pound of air = 0.01574 -- 0.00426 Z 0.01148 ib. Heat of mixing for 1000 lb of air = 1000 X 0.01148 X 130 = 1492 Btu. iota! heat extraction 17,280 + 1492 18,772 Btu per minute. .(5) The weight of solution circulated is 200 X 1.27 (Table 1) X 8.33 = 2116 lb per jninute. Its heat capacity 2116 X 0.631 (Table 1) = 1335 Btu per minute per degree Fahrenheit. The temperature rise 18,772 -5- 1335 * 14.1 F.