| 摘要 |
PROBLEM TO BE SOLVED: To provide an extremely safe structure that prevents electric contact with a lifting pipe, a storage pump and the like even if an energizing electrode should come off a mounting tool. SOLUTION: In a water well housing an anticorrosion metallic body (6), in which a motor (2), strainer (3), pump (4) and lifting pipe (5) are integrated in an underground casing (1); a rod electrode (8) is inserted into a nonmetallic protective cylinder (7), and also, the protective cylinder whose upper and lower ends are fixed with an insulator (9) is inserted and arranged in a narrow space (S) between the bore (R) of the casing and the outer diameter (R') of the anticorrosion metallic body (6). |
