PURPOSE: To prevent a reaction, e.g., explosion, etc. caused by the blending of oxygen, by making a metallic hydride having high discharging power of hydrogen a main storing tank for hydrogen, and a metallic hydride having low discharging power of hydrogen a minor storing tank for hydrogen.
CONSTITUTION: The main thick storing tank 2 for hydrogen consisting of chemically inactive metal is connected through the porous sintered metallic filter 9 to the outlet 6 for hydrogen gas, the on-off valve 7, and the safety leak valve 8 on its top, and through the filter 10 to the minor storing tank 4 having smaller volume than that of the main tank 2 on the bottom on the storing tank 2. the storing tank 2 is charged with the metallic halide 3 e.g., LaNi5, etc. having high discharging power of hydrogen at the same temperature condition, and the storing tank 4 is charged with the metallic halide 4, e.g., CaNi5, etc. having low discharging powder of hydrogen. When hydrogen in the metallic halide 3 is nearly discharged, hydrogen released from the metallic hydride 4 keeps the hydrogen pressure in the storing tank 2 higher the atmospheric pressure outside the tank 2 and prevents oxygen form entering the storing tank 2.
HONDA NAOJIROU