In starting the burner for use, the tank is first filled—not quite full—of strained gasoline. The precaution of straining the gasoline should be taken, to prevent putting into the tank anything that will possibly choke the needle-valve. Alcohol is used for generating the vapor supply, because the flame does not black the iron and fill the room with smoke as in the case when gasoline is used for the purpose. When the alcohol is ignited, the cover is placed in position as shown in Fig. 204, so that the flame may heat not only the generator but also the tank. The object of heating the tank is that the heated gasoline may furnish pressure with which to force the gasoline into the generator. When the alcohol used for generating is almost burned out, the valve F is slightly opened and the burner lighted.
Fig. 205.—Sectional view of gasoline flat-iron generator and burner.
As shown in Fig. 205, the generator G is a brass tube, inclosing the valve-stem G, which terminates in the needle-valve V. This valve regulates the supply of gas admitted to the burner and is operated by the hand-wheel F. When the gasoline in the tank has been heated the necessary amount, the vapor in G is allowed to escape through the valve V. The vapor is discharged into the Bunsen tube, and with it the air is carried in through the openings E, from both sides of the iron. The burner is a brass tube, slotted as shown at H, through which the gas escapes, forming a short flame of large area close to the part of the iron to be heated. The size of the flame is regulated by the hand-wheel F.
The tank is entirely closed, the plug P being provided with a lead washer to insure a tight joint. The plug is further provided with a soft metal center which acts as a “safety-plug” in case of overheating. Should the iron at any time become too hot, the soft metal center will melt and the released pressure in the tank will put out the burner flame. The soft metal center may be renewed with a drop of solder. In case the safety-plug at any time is melted, the hot gasoline will spurt from the opening and immediately vaporize. This of course would, in a short time, produce an explosive atmosphere which if ignited would be dangerous. In case of accident the iron should be carried to the open air and the flame smothered with a cloth.
Alcohol Sad Irons.
—Irons of the same style are also made in which alcohol is used as a fuel. The alcohol irons differ in construction from those using gasoline only in the amount of air that is mixed with the vapor. In general appearance the two styles look very much alike, but in the alcohol iron one of the intakes E is entirely closed and the other opening is partially closed.
Fig. 206.—Gasoline flat-iron operated by an air-pressure fuel tank.
The operation of these irons is identical to those using gasoline, but they are preferred by those who fear the use of that fuel. In reality there is little difference in the danger attending the use of the two liquids. It is only fair to say, however, that the use of any highly volatile fuel is attended with some danger when used carelessly, but with a reasonable amount of care and a knowledge of the mechanism of the machine in use the danger is of minor consequence.