| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a reliable rack and an air diffusion pipe affording reliability to delicate waste water treatment by a biofilm process, as the air diffusion pipe used for a septic tank, such as a contact aerator, and the rack used for the septic tank. <P>SOLUTION: The air diffusion pipe 1 for the septic tank is composed of a coarse mesh square frame by attaching a plurality of blow molded polyvinyl chloride straight pipe-like elliptical pipes 2, 3 and 4. In its constitution, the apexes and bottoms of the major axes of the elliptical pipes 2, 3 and 4 are set in a vertical direction, sockets 16 are integrally molded from bulging surfaces 28 of their minor axes at the time of elliptical shape blow molding, spigots 19 to be inserted into the sockets 16 are integrally molded at both ends of the other elliptical pipes at the time of molding end, and spigot stoppers 21 are arranged around the sockets. As a result, the square frame is securely constituted and the manual work for insertion of the spigots 19 is simplified and in addition, the air flowing in the pipes is not hindered. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
