| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technique of installing an air diffusing pipe comprised of a smaller number of parts which can fully replace conventional techniques using an air diffusing pipe comprised of a greater number of combined parts in sewage in a decomposing vessel. <P>SOLUTION: Thin flexible stainless steel pipes with a large number of air diffusing openings replace conventional air diffusing pipes constituted by combining many parts. In a process of manufacturing the flexible air diffusion pipes, a plurality of air diffusing openings are processed on a belt-shaped flat plate material at proper intervals suitable for air diffusion before forming thin wall pipes. The belt-shaped flat plate provided with many air diffusing openings is formed into a cylindrical shape by roll forming and the thin wall pipes are manufactured by seam-welding line-shaped connecting parts by electric welding, thereafter the flexible air diffusing pipes are formed by carrying out spiral shaped drawing by continuously installed rolling machines. In the technique of inexpensive flexible air diffusion pipes having the small number of parts, the weight of materials is reduced and the time of production is shortened. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
