Flocculation state decision manner, the flocculation state decision device, being the flocculation state decision manner which decides the normality abnormality

摘要

PROBLEM TO BE SOLVED: To enable determination of floc formation state in a flocculation reaction by a simple method.;SOLUTION: A sensor 9 for detecting the distance to a floc using a laser beam is disposed above the water level of a flocculation reaction tank 3. The distance L to the floc is detected, and the variation ΔL of a detection distance at a substantially-short sampling interval (a first setting time T₁) is detected. When the variation ΔL is a set step distance ΔL₀ or more, an OFF signal is sent and when less than, an ON signal is sent. In a normal floc formation, since the floc moves irregularly in water, the detection distance repeats a substantial change. Since the variation ΔL becomes the set step distance ΔL₀ or more, or less than, and the OFF and ON signals are repeated, the floc formation is determined to be normal. In a defective floc formation, the laser beam is usually reflected by the floc of or near the water level because of the dense condition of fine floc, and since the variation ΔL is always less than the set step distance ΔL₀ and the ON signal continues, the floc formation is determined to be abnormal.;COPYRIGHT: (C)2012,JPO&INPIT