| 摘要 |
<p>PURPOSE:To keep a bacteria concentration in a bed constant and to maintain a stabilized fluidizing condition, when waste water is biologically treated in a fluidized bed process, by providing a means, which can remove bacteria from solid particles in the bed, outside the bed. CONSTITUTION:A waste water-purifying tower 1 and a sludge-stripping tower 6 are coupled together through an extracting pipe 7 and a returning pipe 8. When a water level reaches a detector 10, indicating excess proliferation of bacteria in the bed, sludge particles are transferred through an immediately opening valve 11 and the pipe 7 into the vessel 6. In the vessel 6, a heat medium flows through a hot water or water vapor-feed pipe 13 and heats the particles with moisture. Consequently, bacteria on the surface of the particles are substantially annihilated. Heating is done at about 60 deg.C. If mechanical friction is concurrently applied to the particles, the annihilation is more effectively accomplished. The stripped particles are returned through the pipe 8. The stripping operation is continued until the water level 5 becomes lower than that of the detector 10.</p> |
