Document Lp1kz5na2awnNyMN1ELd5q5qw

930 CHAPTER 36 1957 Guide' Table 7. Maximum Tons of Compressor Capacity for CCIjFj Lines* (Only for temperatures indicated) Line Size Inches i HOD % IPS H OD HIPS HOD H IPS 1H OD 1 IPS 1HOD 1H IPS lH OD 1H IPS 2HOD 2 IPS 2H OD 2H IPS 3H OD 3 IPS 3% OD 3H IPS AH OD 4 IPS S IPS 6 IPS 8 IPS. 10 IPS 12 IPS 0.14 .0.17 0.25 0.35 0.55 0.68 1.26 1.43 2.21 2.70 3.40 4.05 6.12 7.66 12.0 12.0 19.1 20.9 27.8 30.2 38.6 40.7 71.3 126 211 352 550 * Refrigerant 12. Suction Lines 105 FBased on Condensing Temperature Psi Pressure Drop per 100 Ft Equivalent Length at 40 F Saturation 1 2345 0.20 0.24 0.35 0.45 0.76 0.94 1.80 2.01 3.12 3.82 4.78 5.75 8.60 10.9 17.1 17.1 27.2 29.4 39.7 43.2 55.2 58.6 100 183 297 503 780 0.28 0.34 0.51 0.65 1.10 1.35 2.57 2.89 4.45 5.37 6.79 8.10 12.1 15.3 24.0 24.0 38.2 42.3 55.7 61.0 78.0 83.0 141 257 422 712 1106 0.35 0.42 0.62 0.79 1.34 1.65 3.17 . 3.54 5.50 6.72 8.42 10.12 15:1 19.2 30.1 30.1 47.8 51.8 69.8 76.1 97.3 103 176 322 523 887 1373 0.41 0.45 0.49 0.54 0.73 0.81 0.93 1.03 1.58 1.75 1.92 2.12 3.76 . 4.15 4.17 4.60 6.38 7.68 9.77 11.6 7.05 8.48 10.8 12.8 17.4 19.2 32.2 24.5 34.6 38.2 34.6 38.2 55.0 60.7 60.0 66.2 80.3 ' 88.7 87.0 96.0 111 123 118 130 203 224 366 403 602 664 1024 1130 1582 1748 Discharge Lines ' Condensing Temperature 115 F 90 F 1.43 1.15 1.87 1.50 2.97 2.38 3.26 2.62 5.05 4.05 5.29 4.25 7.72 6.19 9.16 7.35 10.92 8.75 12.5 10.0 19.2 15.3 20.6 16.5 32.2 25.9 32.2 25.9 51.5 39.8 64.5 43.8 72.0 57.6 78.8 63.3 95.8 101.6 171.5 266 77.1 137.8 214 461 370 725 582 1041 836 -- Oil separators are installed between the compressor and condenser to prevent excessive oil removal from the compressor crankcase and its passage into the condenser and evaporator. The oil is separated from the gaseous refrigerant by gravity during its passage through a chamber of sufficient size to reduce the velocity. A float-operated valve maintains a maximum oil level in the separator, and additional oil is forced by pressure difference through a line back to the crankcase. Screen strainers are frequently installed in the liquid line piping before solenoid valves and expansion valves, as well as before regulating valves in water lines leading to water cooled condensers. Sight glasses which permit visual inspection of the condition of the refrigerant are sometimes installed on factory assembled commercial unit systems. It is particularly advisable to place such a fitting before the expansion valve, if the evaporator is located above the condenser. Flexible vibration eliminators, usually consisting of a bellows design covered with woven copper wire, are sometimes installed in copper lines where units such as compressors are installed on flexible mountings, or Table 8. Approximate Suction-line Capacity Factors for Equal Pressure Drop of CCIjFi (Refrigerant 12) . Saturated Suction Temperature, F. 50 40 30 20 10 0 -10 Factor............................................ 1.09 1.00 0.92 0.86 0.80 0.74 0.66 Refrigeration 931 where vibration is otherwise a problem. Packed or packless shut-off valves are necessary where it may be required to isolate portions of a system. EQUIPMENT CHARACTERISTICS AND SELECTION The various types of compression systems have quite different charac teristics of capacity and power with varying evaporator and condenser temperatures, as may be noted from curves in Figs. 15 and 16. From Fig. 15 it may be observed ttat power requirements for the centrif ugal compressor increase much more rapidly than for the reciprocating compressor, with increase in evaporator temperature. Similarly, the,ca pacities of the steam ejector and centrifugal compressors increase more rapidly than those of the reciprocating compressor with increase, in ,evapor rator temperature; Thus, both the steam jet and centrifugal machines tend to be more self-regulating than the reciprocating. It is also, evident from Fig. 15 that the steam jet equipment is best suited for operation at mgh evaporator temperatures. .. The effect of condenser temperature upon the power and capacity of the different types of compressors is shown in Fig. 16. It may. be-noted that the power required by the reciprocating compressor increases rapidly, with increase in condenser temperature, while the power curve for the centrifugal compressor is relatively flat. It is also evident that the ca pacity of the steam jet compressor is independent of condenser temperature until a certain point is reached, where it drops to zero. As. previously stated, steam jet equipment requires more condensing, water than other types of compression systems. Consequently, steam jet systems are well