OIL FUEL USED IN CONJUNCTION WITH COAL TO MEET PEAK LOADS AND FOR BANKED FIRE PERIODS.
In an article in the June 20, 1911 number of "POWER," Mr. Herbert A. Wagner describes an arrangement of furnace design whereby oil is used for the above purpose.
The boilers are the B. & W. type rated at 65o H. P. each. The oil is fired from the rear, four (4) burners being fitted to each boiler. By shortening the bridge wall and putting in a horizontal baffle on the bottom row of tubes from the bridge wall to the rear end of the tubes, the gases of combustion for both oil and coal traverse the same path, the second vertical baffle being also shortened. Air to support the combustion of the oil is taken in from the rear.
The following results having been obtained with this arrangement: One per cent. of the total evaporation is used to atomize the oil.
It was found to be cheaper to bank with oil than with coal.
One burner is used for a pilot and for banking. Furnace changes were slight.
With coal alone 1188 B. H. P. was developed. With oil alone 702 B. H. P. was developed. With oil and coal together 1445 B. H. P. was developed.
With oil and coal together a maximum for one hour with one boiler was 1632 B. H. P.
"It has been found that 2000 K. W. of station load can be carried by each boiler when using coal and oil together with as much ease and certainty as 1200 K. W. per boiler can be carried by coal alone. This shows under operating conditions a gain in capacity of 663 per cent. by the use of oil or a saving of 4o per cent. in the cost of the boiler plant for a given capacity." "Tests have shown that a cold furnace with water in the boiler at 142 degrees F. could be made to steam at 175 lb. pressure in 25 minutes with oil fuel as com pared with 42 minutes with coal." "May 12, 1911 : The steam station was carrying 2000 K. W. with four coal-fired boilers in service and four additional boilers banked by means of one oil burner under each. The transmission service was suddenly in terrupted and a load of 760o K.W. thrown on the steam plant. Oil was turned onto the four boilers in service and the four banked boilers; the steam pressure was main tained and in four minutes the boilers were blowing off."
Oil Fuel for Forge Work, Annealing Furnaces, etc.
The adoption of oil fuel for forge and furnace work by the U. S. Government and many large railway and manufacturing shops, is the result of extended experi ments to determine the most suitable fuel for this class of work.
The wide range of regulation, the ease and rapidity with which a welding heat can be obtained on large and small work, combined with simplicity of apparatus and minimum labor charge, all show the superiority of the liquid fuel.
By the use of two valves the operator has his fire under perfect control at all times and can change instantly from a slow annealing to a dazzling white heat. When the work is ready for the hammer, the oil may be entirely shut off until ready for use again affecting a considerable saving in fuel in this way.
In the repair and straightening of structural iron work, the fire may be carried to the work by means of small fifteen or twenty-gallon oil holders, doing away with the expensive handling of heavy work.
In annealing furnaces an even heat of any desired intensity can be maintained over large areas. The boiler maker finds this feature especially desirable in flange and other similar work.
For welding large or small work, drop forge process es, forging crank shafts and other large work the oil fuel is invaluable. Long irregular-shaped pieces are readily brought to any required heat in the oil furnace.
The following data was obtained at representative plants using oil in steel, brass, and annealing furnaces.
20 gallons of oil required to "bring down" ioo pounds of steel, 3 hours required to "bring down" six pots of steel containing ioo lbs. each.
2 gallons of oil required to melt ioo lbs. of brass using a 12 ounce air pressure, 4o minutes to "bring down" a charge of Soo lbs. of brass.
Annealing Furnaces.
8 Brown & Sharpe, No. 2 case hardening furnaces, arranged in pairs.
burner to each furnace.
Atomizing air at 1M lb. pressure from a positive pressure blower driven at 175 R. P. M. and delivering 3.75 Cu. Ft. per revolution.
Oil Pressure on burners, 7 lbs.
gallons oil per hour for 8 furnaces.
soo to 1800 degrees F. is the uniformly distributed heat of the furnaces.