METHOD FOR DETECTING FLOCCULATION CONDITION OF SUSPENSION

摘要

PURPOSE:To quickly detect the flocculation condition of a liquid mixture composed of suspension and flocculating agent from a quantity of received light by injecting the flocculating agent into the suspension in the stirring region between a light emitting device and a light receiving device. CONSTITUTION:Stirring vanes 12 are quickly rotated by an electric motor 14 at the time t1 when the supply of the suspension into a stirring tank 10 is completed. A stop valve 27 is thereafter opened for the prescribed time at the time t2 to inject a prescribed amt. of the flocculating agent from a supply source 28 into the tank 10. Flocs 17 are gradually flocculated in the liquid mixture 11 and the quantity of the light received in the light receiving device 20 increases gently when the flocculating agent is injected into the tank at the time t2. The flocs are further formed when an impeller 12 begins to be slowly rotated at the time t3. The diameter of the flocs increases and the quantity of the light received in the device 20 increases as a whole while increasing little by little. The flocs 17 are sufficiently flocculated and the diameter thereof no longer changes so that the quantity of the received light flattens when the time t4 is attained. An arithmetic unit 36 calculates the diameter, number, volume and effective density of the flocs 17 from the quantity of the received light. The flocculating condition of the flocs 17 is thus known.