Water is supplied to the boilers from a hot well of an average temperature of 165° F. through a Dow duplex pump, 10 by 8 by 10 inches. A series of readings gave the average stroke of this pump as 26. 1 revolutions a minute with a corresponding average boiler pressure of 138 pounds. Allowing 10 per cent slippage for this pump, this is equivalent to 1,404.26 boiler horsepower developed. Of this amount the company charges about 350 boiler horsepower to the steam and combination stills-an estimated percentage that is approximately correct. Owing to the arrangement of the equipment it is not possible to determine actually the amount of steam used. The writer is indebted to Mr. C. Stamm, refinery superintendent, for the figures concerning steam consumption. If the heat of the exhaust steam be considered as otherwise wasted energy, for each 100 barrels of crude oil treated in the topping plant the net heat expended to produce the various fractionated products from the oil treated is as follows: Heating value in 1 barrel of this crude.... Fuel used to treat 100 barrels of crude in topper, 1.6 barrels of 18° B. gravity... B. t. u. 6,063, 800 9, 938, 240 Fuel used in rerun plant to treat the distillate made from 100 barrels crude (0.92+24. 2 barrels).. 1,366, 508 Heat used to make the steam supplied in treating 24. 2 barrels of distillate (boiler efficiency 86 per cent)....... 1,930, 870 Total net B. t. u. used in treating 100 barrels of crude.. 13, 235, 618 132, 356.2 Per cent. Proportion of fuel used to amount of crude run.. WATER CONSUMPTION. 2.18 The cooling water used in the condensers is not metered, and, except for the power required to deliver it, does not constitute a charge against the plant. The revolutions of the pump show a delivery of 1,800 gallons a minute, an average of approximately 3.5 barrels of cooling water being used to one barrel of crude oil treated when the plant is operated at normal temperatures. FLEXIBILITY. Although this plant is running a clean oil of 26° B. gravity (specific gravity, 0.899), its adaptability is not confined to one oil. The Gaviota plant of this type, previously mentioned, is handling an oil of 18° to 20° B. (specific gravity 0.946 to 0.934) containing as high as 20 per cent briny water with equal efficiency, although the capacity, of course, is reduced. Oils that would cause foaming and frequent cleaning in the crude stills can be handled in the pipe retorts without trouble. FIRE HAZARD. No fires have occured with these toppers during operation, and the No. 1 plant has been operating continuously since August 1, 1915. REPAIRS. Topper No. 2 began operation in January, 1916, and the only repair necessary was in connection with the burning of two tubes in May; new tubes were quickly fitted to replace those destroyed. The repair charges have therefore been minimum. The light auxiliary walls inclosing the fittings at the ends of the tubes probably justify themselves, as they result in a distinct heat saving, and, being constructed of weak mortar, are easily removed when repairs are necessary. It should be noted that little time is wasted in waiting for the retorts to cool for repair work, as the work is performed entirely from the exterior of the furnace. COST DATA. COST OF LABOR. The pay roll given on page 10 constitutes the daily labor charge for operation against the entire refinery. Practically this charge should be divided between the crude stills and the toppers, proportionately to the crude run, and the toppers should therefore be charged $24. 47 a day. COST OF TOPPING PLANT. An approximate estimate of the cost of construction of the topping plant, based on costs of labor and material in 1914, is given in Table 8 following. TABLE 8.-Cost of constructing Bell topping plant, Avon refinery. 4 combination stills and towers... 2 steam stills and towers.. 10 condensers.. 6 look boxes. Total... STEAM AND COMBINATION STILLS. $1,628 $4,588 $12, 124 $8,880 $15,760 $3,276 $1,120 $5,784 $53,160 226 1,589 790 843 3,200 6,380 2,780 5,400 11, 498 2,644 12,557 15,747 12,080 32,658 3,276 308 4,508 16,074 17,379 38, 827 3,600 3,600 1,428 31,271 a111,661 a of this total, $75,930 is chargeable to crude-still battery, and $35,731 is chargeable to the Bell toppers. COST PER BARREL OF CAPACITY. Considering the proportionate charge of the rerunning plant for the amount of distillate handled from the toppers, the entire first cost of a plant of this type is estimated at $80,087, or $12.80 per barrel of normal daily capacity. CHANGES AND IMPROVEMENTS POSSIBLE. Probably many improvements can and will be made in the construction of the various units as the necessity of saving heat becomes more insistent. The furnace construction might be changed to enlarge the combustion chamber, as the experiments subsequently discussed indicated that the damper and the air supply could not be adjusted to reduce the proportion of excess air below 50 per cent of that required. In the writer's opinion it is questionable whether even that rate of combustion could be maintained without superheating the coils. With a larger combustion chamber removing the flames from direct contact with the pipes the proportion of excess air could undoubtedly be reduced; also the coils might be raised somewhat higher to advantage. As with other furnaces of various types, it is the writer's opinion that the air required for combustion could be preheated by passing it through a flue under the combustion chamber, resulting in a saving of fuel and also in a beneficial effect on the foundations by reducing the excessive temperature stresses in them. This flue could be equipped with a damper for regulating the air supply. The tendency around a refinery is to regard oil fuel a plentiful and therefore a cheap commodity; moreover, it is a fuel easily fired and easily wasted. The separating towers used with the topper cause the oil and the vapors to be intimately associated during the separation; that is, vapors do not instantly leave the oil upon separation, and absorption of the vapors, combined with the mechanical entraining of discoloring heavy oils, undoubtedly occurs. Residuum from the toppers running at the same temperature as that of the crude stills on the same oil flashes at about 10° F. lower temperature. Also the first-run distillate from the toppers is somewhat discolored. Any distillates absorbed by the residuum results in clear loss unless the residue is to be further fractionated. In the rerunning plant the tower used undoubtably accomplishes the desired result-the production of water-white homogenous fractions. Also owing to the absorption obtained by the incoming distillates, unquestionably a large percentage of the light gases is recovered, and the refining losses are materially reduced. The Avon company is now operating its steam and combination stills in series, charging each successive still through its tower with the residue from |