CHAPTER XXI

BURNER CLASSIFICATION IN FUEL OIL PRACTICE

In 1902 and 1903 the U. S. Naval Fuel Oil Board made an exhaustive inquiry into burners of various types. In their report a classification of burners was set forth which comprehensively details the fundamentals of various types of burners known as the drooling, the atomizer, the chamber, the injector, and the projector types.

In the drooling type the burner allows the oil to drool from an upper opening down to a lower opening from which the steam is issuing. An atomizer burner allows the oil to drop directly on the steam. The chamber or inside mixer atomizes the oil within the burner after which it issues from an orifice of the desired form. An injector burner is designed primarily to operate without a pump as it is presumed that the oil will be sucked from the reservoir by the siphoning or injector-like action of the steam jet inside. In the projector burners the steam blows the oil from the tip of the burner.

Two other general classifications prevail depending upon the character of the flame emitted-namely, the fan tail and the rose. In the former type the burner produces a flat flame while in the latter a circular flame is sent forth.

The three principal types of burner that are encountered in central station practice are, however, known as the inside mixer, the outside mixer, and the mechanical atomizer.

The Inside Mixer.-In burners of this class, the steam and oil come into contact, and the oil is atomized inside of the burner itself, and the mixture issues from the burner tip ready for combustion at once. The Hammel burner is of this type.

The accompanying Figure 95 illustrates the construction of this burner. Oil enters at A, flows through D into the mixing and atomizing chamber C; steam enters at B, passes through F, E, and then through three small slots, G, H and I, into mixing chamber C where it meets the oil, and as these small steam jets cut across the oil steam at an angle, the energy of the steam is utilized.

The burner requires for its operation about 2 per cent. of the steam generated by the boiler. The heavy hydrocarbons of the

FIG. 95. The inside mixer type of burner.

In burners of this type the steam and oil come into contact and the oil is atomized inside the burner itself. The mixture then issues from the burner tip ready for combustion. The Hammel burner shown in the illustration above is of this type.

oil are atomized, the light hydrocarbons are vaporized, and the completed mixture issues from the burner and ignites like a gas

FIG. 96.-Typical burners and control pipes ready for installation.

flame. In normal service there is no tendency to carbonize, and the only way in which carbonizing can be caused is by turning off

the steam and leaving the burner filled with oil instead of blowing it out before shutting down.

All oil is usually more or less gritty and will cause wear of some part of the burner. This is provided for in the Hammel burner-the removable plates KK can be quickly replaced.

The Outside Mixer.-In the outside mixing class the steam flows through a narrow slot or horizontal row of small holes in the burner nozzle; the oil flows through a similar slot or hole above the steam orifice, and is picked up by the steam outside of the burner and atomization thus accomplished. The Peabody burner is typical of this class. It will be noted that the portions of the burner forming the orifice may be readily replaced in case of wear or if it is desired to alter the form of the flame.

FIG. 97. The outside mixer type of burner.

In this type of burner the steam flows through a narrow slot or horizontal row of small holes in the burner nozzle. The oil flows through a similar slot or hole above the steam orifice and is picked up by the steam outside of the burner and thus atomized. The Peabody burner which is shown in this illustration is a typical burner of this type.

There are many other makes of oil burners on the market, which operate on the same principle as the Hammel or the Peabody burner. A few of these are illustrated on the following pages, Figures 98 to 106 inclusive.

An Example of the Mechanical Atomizer. As an illustration of one of the many interesting types of burners that produce atomization by the mechanical process, let us consider for the moment the rotary burner of the Fess System Company. The mechanism that accomplishes the atomization is operated by a small electric motor as shown of 14 to 13 hp. The motor operates a rotary pump through a worm gear. This pump brings the crude oil from the storage tank and applies it to the burner, which is placed in the center of the fire box. The burner rotates

at a sufficient speed to thoroughly atomize the oil by centrifugal force and by the proper admission of air a smokeless flame is produced equally distributed throughout the fire box.

FIG. 98. The Leahy oil burner.

The Leahy burner is an outside mixer and is made either for the back firing (Fig. 99) or front firing (Fig. 98). The burner equipment includes a bypass valve, two quick action unions, special oil regulation valve and oil strainer.

FIG. 99.

The Home-Made Type of Burner.-Patented oil burners are practically unknown in the oil fields. Every operator makes his own burner out of ordinary fittings. The construction varies

FIG. 100.-The Witt burner.

This is an outside mixing burner with removable steel tip. The above illustration shows a backshot burner suitable for a Peabody furnace.

FIG. 101. Here is shown a Witt inside mixing burner for front firing.

This is a steam atomizing burner, the oil being controlled by a needle valve in the burner head and the steam by a separate valve in the steam pipe near the burner. The length of burner and size of opening are arranged to suit each particular installation.