To connect these tanks, all that is required is a piece of 1-inch iron pipe, h, 12 inches long, with a coupling on one end. To operate this air holder, close the two air cocks on the lower, or air, tank; then fill the upper tank nearly full of water, taking care not to put too much in it, or it will overflow the lower tank and get into the tubes, and if this happens the tubes will have to be removed and hung up to dry, or drops of water will be blown into the blow pipe and extinguish the flame. It is then ready for use. The air in the air chamber is compressed by the weight of the water in the upper tank, and if the water line is at the same hight as the acid line in the hydrogen gas generator the pressure of air must be the same as the pressure of gas. As air is used the water descends through the pipe and will gradually fill the lower chamber. It can then be forced back into the water chamber by attaching the air pump to the cock h in Fig. 9, or d in Fig. 10, without disturbing the gas or in any way interfering with the operator. To connect with the cock h in Fig. 9 it is only necessary to disconnect one line of hose and connect the pump; then close the other cock and work the pump until air bubbles up in the upper tank; then shut the cock, remove the pump and connect the hose to the gasoline can, open the cocks and the apparatus is ready for use.
Air Holder No. 2.
To make the air holder shown in Fig. 11, take a sheet of No. 26 gauge galvanized iron 30 inches wide. Make it into a cylinder 26 inches in diameter, double seam a flat bottom on it, and wire the top with ¼-inch iron rod, which will make it stiff enough to withstand the pressure of water. Close to the bottom and 3 inches apart punch two holes, a and b, large enough to receive ⅜-inch galvanized pipe couplings. Solder these couplings in place.
On the inside of this tank and into these couplings screw two pieces of ⅜-inch pipe 4 inches long with elbows pointing straight up. Into these elbows screw two pieces of ⅜-inch pipe long enough to come flush with the top of the tank F. On the outside of the tank and into the ⅜-inch couplings screw two ⅜-inch nipples 2 inches long, and on these nipples screw two ⅜-inch hose end gas cocks.
Fig. 11.—Air Holder No. 2.
Now, with the same sized sheet iron, make another tank 2 inches smaller in diameter than the first tank. This should have a flat bottom, and be wired as previously described. Then take four strips of sheet iron 30 inches long and 2 inches wide, and form each into V shape lengthwise. Lay off the circumference of this tank in four equal spaces. One side of the V-shaped pieces should then be soldered on at each space. The other side should be left loose to allow for adjustment. These pieces form the guides to the upper tank and prevent it from tipping sideways and binding. Two of the guides are shown in the illustration, Fig. 11.
The lower tank should now be filled about one-third full of water. The upper tank should then be inverted and placed in it. The air pump must then be connected to one of the ⅜-inch cocks with a short piece of hose, and the air should be pumped into it until the upper tank rises to its highest level.
The pressure in this form of air holder must be regulated by weights, and to secure 1 pound of pressure it is necessary to place weights equal to 1 pound for every inch in area contained in the opening in the upper tank. Two drop handles, such as are used on heavy milk cans, should be riveted and soldered on the sides of the tank to facilitate moving it about.