| 摘要 |
PURPOSE:To increase the degree of concentration of sludge by feeding bubbles into raw water in a primary treatment vessel, performing the floatation of solid content contained in the raw water by means of bubbles till the critical concentration and thereafter feeding the floated solid content to a secondary treatment vessel to float the solid content. CONSTITUTION:A feed port 2 of raw water is opened in the central part of a primary treatment vessel 1 and also a cylindrical cover 3 surrounding the feed port 2 is provided and a feed port 4 of pressurized water contg. bubbles is opened to the side face of the cover 3 and raw water is mixed with the pressurized within the cover 3. Thus upper layer water contg. the solid content which is accumulated on the upper part of the vessel 1 is scraped onto a discharge gutter 9 provided to the upper part of the vessel 1 by means of a scraper 7 and sent to a secondary treatment vessel 10. The upper layer part of the secondary treatment vessel is successively scraped with a scraper 11. Thereby, the solid content high in degree of separation from water is taken out. |
