| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent scum or the like from accumulating on the water surface of a septic tank, bubbles from heaping up above the water surface and a bad smell from emitting by defoaming by using a defoaming device having a downcast slope part and a downside plane part floating almost on the water surface while dragging downward the stream flowing to the slope part along the dirty water surface. SOLUTION: This defoaming device has the slope part 3-3a, which is used for changing downward the direction of the surface stream of dirty water, and plane part 3-6a, which is at almost the same level as the water surface and is used for defoaming in collaboration with the downcast slope part 3-3a. Almost all of bubbles rising up to the water surface contain gases generated by anaerobic digestion treatment. The parts 3-3a and 3-6a change downward the direction of the stream flowing along the surface of the dirty water containing air sufficiently while keeping fixed positions to the water surface. By using this defoaming device, the bubbles coming up to the dirty water surface are dragged in the downward stream and contacted with the air contained in the stream of the dirty water to vanish the bubbles.</p> |
