A two-inch pipe was run from the tanks to the oil ptimp to provide suction to the pump, and a pipe 1% in. in diameter was run from the pump and along the front of the boiler, from which a connection wa4rovided to each burner. A pressure relief valve was installed in the discharge line from the pump and releasing into the suction line. This valve affords relief in case the pres sure on the discharge line should go higher than desired. A pressure gauge was installed on the discharge line so that the operator can know at all times the pressure of oil supplied to the burners.
The main steam header in the boiler room was tapped and a connection made for the branch steam line to supply steam for operating the oil pump and for atomizing the oil at the burners. A connection was made from this branch line to each burner.
The pump for supplying oil under pressure to the burners is an ordinary duplex, piston-type steam pump, equipped with a con trol governor for maintaining a steady pressure on the oil dis charge line.
To furnish steam for operating the oil pumping system when the main boilers are cold, an auxiliary upright "Donkey" boiler of 6 to 10 H. P. capacity was provided. As soon as steam is raised on the main boilers this auxiliary boiler is cut out of the system and the fire allowed to die out. Fuel for firing the small boiler is largely furnished by the paper and refuse collected from the school rooms on the preceding day.
Fig. 101 shows the installation in the Chicago schools.
Owners of large and small apartment houses have been quick to see the advantages and the ultimate economy of burning fuel oil. Fig. 102 shows the boiler room of a modern apart
ment house. The oil is pumped from an underground tank 100 feet distant. This equipment operates one low-pressure steam heating boiler and one water heater. This building is furnished with a steady steam pressure automatically regulated at four pounds gauge pressure, and with hot water at 140°.
Steam heating companies usually estimate that each square foot of direct steam radiation will require 500 lbs. of steam per season. In Federal buildings with a heating and ventilating apparatus, each 7,000 cu. ft. of contents will require 1 boiler horse power. Under normal conditions 1 B. H. P. will supply 138 sq. ft. of radiation. One square foot of steam radiation gives off about 260 B. t. u. per hour and 1 square foot of water radiation gives off about 160. One B. t. u. will raise the temperature to 55 cu. ft. of air 1 degree F. One pound of oil will evaporate approximately 12 lbs. of water per hour in a heating boiler and 100 sq. ft. of radiation will require 33 1/3 lbs. of water per hour.
Fig. 103 shows a sectional view of a residence where fuel oil is used for the heating boiler and in a brick set kitchen range. Fig. 104 shows a fuel oil burner applied to a hotel range. The close regulation of heat possible with an oil burner makes fuel oil an ideal fuel for ranges and for bakeries. Fig. 105 shows a bakers' oven burner., When firing is finished this burner swings ha& Out of the way and lies flat against the side of the oven.