Document kmKeDaQYXEe6Bnj0XgGo13X4D

American Society of Heating and Ventilating Engineers Guide, 1929 VACUUM HEATING PUMPS Return line vacuum heating pumps may be of the following types: (1) Direct acting reciprocating steam driven return line vacuum pumps; (2). reciprocating power driven return line vacuum pumps; (3) motor driven return line vacuum pumps, of the centrifugal or rotary type having one of the following arrangements: Table 9. Characteristics of Centrifugal Return Pumps and Receivers Delivering Against 15 Lb. Size 101 102 103 104 105 Sq. Ft. Equivalent Direct Radiation Gal. per Min. 8000 16,000 26,000 40,000 65,000 ii 22 35 60 90 R. P. M. 1725 . 1725 1725 1140 1140 Actual H. P. 0.4 0.6 0.8 1.0 1.4 H. P. Motor Supplied Floor Space H, Si 1 m 2 5' 3'x3'8' 5' 3'x3' 8" 6' 7' 6'x4'2' 7'6'x4'2' Shipping Weight 700 700 750 1050 1100 Table 10. Sizes, Speeds, Horse Powers and Capacities of Motor Driven Condensation Return Pumps Rating in Sq. Ft..................... Discharge Pressure, Lb Gallons per Min...................... H. P. Motor..... ..................-- R. P. M. 60 Cycle and D. C... R. P. M. 25 Cycle--................ Shipping Weight..................... 0-2000 10 20 33 % Si 1700 1700 1440 1440 330 350 2000-4000 10 20 66 H Si 1700 1700 1440 1440 350 370 4000-8000 10 20 10 10 Vs Si 1700 1700 1440 1440 420 440 8000-16000 10 20 20 20 Vs Vi. 1700 1700 1440 1440 535 565 Table 11. Motor Driven Condensation Pump Capacities for Delivering Against Various Pressures Radia tion in Sq. Ft. of Direct Radia tion Minimum Gallons per.Min. Maximum Boiler Pressure Lb. Motor H. P. 4000 4000 4000 6-8 6-8 6-8 10 15-40 50-60 Vi a v< 6000 6000 6000 9-12 9-12 9-12 10 15-40 50-60 Vi Vi. 1 8000 8000 8000 8000 10,000 10,000 10,000 10,000 10,000 12-16 12-16 12-16 12-16 15-20 15-20 15-20 15-20 15-20 10 15 20 30-60 10 15 20-30 3040 50-60 V, Vi. 1 IM V Vi. 1 1M 2 Sug gested Size of Piping Inches i i i m im lA m Wi. m ih m m m Radia tion in Sq. Ft. of Direct Radia tion Minimum Gallons per Min. Maximum Boiler Pressure Lb. Motor H. P. 15,000 15,000 15,000 15,000 15,000 ,20,000 20,000 20,000 20,000 20,000 25,000 25,000 25,000 25,000 25,000 30,000 30,000 30,000 30,000 25-30 25-30 25-30 25-30 25-30 30-40 30-40 3040 3040 30-40 40-50 40-50 40-50 40-50 40-50 50-60 50-60 50-60 50-60 10 15 20r30 40 50-60 10 15 ,, 20 30-40 50-60 10 15 20 3040 50-60 10 15 20 30-60 Vi. i m. 2 3 Vi. 1 2 3 5 1 1H 2 3 5 1 1A 2 5 Sug gested Size of Piping Inches 2 2 2 2 .2 2 2 2 2 2 2A 2A 2A 2A" 2*2 2A 2A 2A 2A~ 294 Chapter XVIII--Pumps and Traps for Heating and Ventilating Equipment (a) One pumping unit and motor lor handling both air and condensate. (b) One pumping unit and motor for handling air and a separate pumping unit and motor for handling condensate. (e) One pumping unit and motor for handling condensate with an air ejector operated by a recirculated portion of the condensate for handling the air. (d) One pumping unit for handling condensate and another for handling the air, both operated by one motor. The volumetric displacement rate of the water cylinders of steam or power driven reciprocating return line vacuum pumps should be from 8 to 10 times the volumetric rate of flow of the condensate to be handled. The piston speed in feet per minute of steam or power driven recipro- Fig. 4. Method of Discharging High-Pressure Apparatus into Low-Pressure Heating Mains and Vacuum Return Mains through a Low-Pressure Trap eating return line vacuum pumps should not be more than 20 times the square root of the number of inches in the length of stroke. The speed of crank shafts of power driven reciprocating return line vacuum pumps should not exceed 40 r.p.m. The type of drive to be employed between motor and . pump may be chain, belt or gear. When gears are used they should be of a type which will be quiet in operation. The receiving tank may be placed either on the suction or on the dis charge side of the pump; generally on the suction side of centrifugal or rotary pumps and on the discharge side of reciprocating pumps. The capacity of receiving tanks, when placed on the suction side of pumps, should be proportioned to the operating condition to be met. To this end its capacity should be such as to retain the condensate and to take care of fluctuations between the rate of returning condensate and the rate of the pump delivery. This capacity in case of automatically controlled units should be the capacity of the tank in gallons between the high and low water' levels in the tank, as determined by the water line control, and when not. otherwise provided for, should be in accordance with Table 12. Air capacities of vacuum heating pumps are in general referred to as equivalent cast-iron direct radiation, and may be assumed on a decreasing 295