Document qaz8KG1z1KgeGpLXLrr0ZkQ1n

HEATING VENTILATING AIR CONDITIONING GUIDE 1940 Concentration Pound Mold (42.4 lb) LiCl peb 1Q00 lb Water Table 8. 0 Density of Lithium Chloride Solutions Temperature Deo F 50 100 ` 150 200 250 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 1.090 1.124 1.156 1 188 1 217 1 242 1.043 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 1.2l5 1.237 1.568 1.278 1.296 1.312 1.327 1.34 32 300 1.267 1.286 1.302 1.318 1.33 1.35 a finely divided spray of the brine but more generally by passing the air over a metal surface coil where the liquid absorbent presents a large surface to the air stream. The difference in vapor pressure causes some of the vapor in the air-vapor mixture to migrate into the brine. Here it condenses into liquid water and decreases the concentration of the absor bent. In order that the process be continuous means must be provided for counteracting the diluting effect of the extracted moisture and also for maintaining the temperature of the brine sufficiently low to hold the desired vapor pressure. As the water vapor is added to the absorbent and condenses, it gives up its latent heat of condensation which tends to raise the temperature of Table 9. Viscosity of Lithium Chloride Solutions (millipoise) CONCENTRATION IN POUND MOW (42.4 LB) PER 1000 LB WATER Temp. Deo F 02468 10 12 14 16 18 : 20 22 24 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 56.75 72.44 97.05 136.8 28.91 37.07 47.42 63.09 84.94 15.45 19.91 25.53 32.58 43.05 58.48 11.02 14.26 18.37 23.55 30.90 41.40 8.61 11.19 14.42 18.62 24.32 32.28 6.82 8.89 11.48 14.94 19-56 25i59 5.60 7.31 9.51 12.30 15.92 20.99 4.70 6.15 8.07 10.42 13.43 17.66 4.01 5.25 6.92 8.93 11.51 15.00 3.48 4.56 6.01 7.78 10.00 12.91 3.05 4.01 5:28 6.86 8.79 11.22 2.72 3.58 4.72 6.14 7.83 9.93 2.43 3.21 4.25 5.50 7.02 8.83 2.19 2.90 3:84 4.94 6.46 7.91 2.00 2.66 3.52 4.51 5.75 7.19 1.86 2.48 3.28 4.17 5.32 6.67 1.74 2.32 3.08 3.89 4.94 6.19 199.5 123.3 178.6 81.10 116.1 56.62 79.80 43.45 60.26 33.96 46.13 27.67 36.64 22.96 30.06 19.36 25.06 16.56 21.28 14.32 18.28 12.59 16.00 11.12 14.09 9.91 12.47 8.97 11.27 8.28 10.38 7.73 9.64 165.6 111.2 82.04 61.52 48.31 38.99 32.14 27.10 23.12 20.14 17.62 15.50 14.00 12.82 11.86 156.3 113.8 84.72 65.77 52.48 42.76 35.48 29.92 25.64 22.18 19.36 17.22 15.70 14:45 118-5 89.95 71.12 95.94 56.89 75.86 46.45 60.67 38.55 50.70 32.96 43.05 28-31 36.98 24.60 31.92 21.78 28.05 19.68 25.12 18.03 22.80 106.2 84.33 67.92 56.49 47.42 40.55 35.56 31.92 29.11 42 li CHAPTER 2. REFRICERANTS AND AIR DRYINC AGENTS both the absorbent and the moist air stream. For every pound of water absorbed and condensed the heat added to the air stream arid the brine combined is obtainable from steam tables. For instance, at 60 F the amount of this heat is about 1057 Btu. In addition to this heat there is involved also the so-called heat of mixing which is frequently considerable. ' Temperature-Pressure-Concentration Relations Since the absorption process can continue only as long as there is a difference in vapor pressure between the absorbent and the air-vapor mixture and since at a given temperature of the absorbent the vapor pressure depends on the concentration of the solution, evidently there must be a relation between these quantities which if known would state the limits of the process. The relationship would also depend on the absorbent being used, and would have to be determined for each substance Table 10. Properties of Lithium Chloride Solutions Concentration Pound Mots (42.4 lb) LiCl per 1000 lb Water Partial Heat or Mixing at 0 F BT(J per lb Temperature Cobp. o? Partial Heat or. Mixing BTU per LB PER F Specific Heat at 70 F Boiling Point F (at 760 MM Hg.) Freezing Point 0 0.0 0.0 0.998 212.0 32 2 2.04 -0.014 0.901 215.8 16.3 4 7.24 -0.036 . 0.831 221.5 -5.8 6 16.7 -0.069 0.778 228.9 -34.2 8 31.9 -0.109 0.739 238.1 -69 .. 10 51.1 -0.143 0.710 248.4 -90 12 75.7 -0.160 0.687 258.8 -40 14 90.8 -0.167 0.666 268.9 1 16 124.8 -0.176 0.647 277.9 36.5 18 145 . -0.186 0.631 285.8 58.1 20 162 -0.194 0.617 293.2 86.4 22 171 -0.20 0.604 300.2 133 24 177 -0.20 0.59 307 156 26 182 -0.21 0.58 313 180 28 191 -0.21 0.575 318 190 30 194 -0.21 0.57 323 195 32 198 -0.22 0.56 328 280 Substance that First Separates Out on Freezing Ice Ice Ice Ice Ice Ice LiCLZH-P LiCl-W-JQ LiCl-2HiO LiCUlHfi LiCl-lW LiCLlhO LiCl-IW LiCi-H-P LiCl-HtO LiCl-HtO LiCl used as an absorbent. Fig. 2 shows this relationship graphically for lithium chloride. It will be noted that this chart is essentially similar to that shown in Fig. 1 and its direct usefulness is limited by much the same considerations. In order to permit numerical calculations of air conditioning problems it is desirable to have tables for use instead of a chart like Fig. 2, and Tables 7, 8, 9 and 10 can be used in making calculations for lithium chloride. Instead of tabulating the vapor pressure of the solution of lithium chloride it is preferable to tabulate the dew-point of air in equilibrium with lithium chloride, since it is easy to interpolate between values of the dew-point and not so easy to interpolate accurately between values of vapor pressure. The values for dew-point may be converted to vapor pressures, relative humidity, and wet-bulb of air in equilibrium by means' of the usual psychrometric chart or formula. 43