| 摘要 |
<p>PROBLEM TO BE SOLVED: To selectively and at high purity recover a fraction containing much specified material to be treated (solid or liquid) having specific density equal to that of liquid from material to be treated (object to be treated) having wide distribution of specific gravity centered about specific gravity 1. SOLUTION: When subjecting material to be treated having specific gravity equal to that of liquid to fractionation treatment by using a device for using centrifugal force by a turning flow of liquid to be treated to separate the material to be treated upwards or downwards by a difference in specific gravity of the material to be treated and liquid, the quantity of liquid discharged to below the device is enlarged compared with that of liquid discharged to above the device, thereby material to be treated (solid or liquid) having specific gravity equal to that of liquid is recovered from liquid discharged to above the device. Concretely, in a liquid cyclone, the ratio S1 /S2 of sectional area of an upper withdrawal pipe (immersion pipe) 18c to that of a lower withdrawal pipe 20c is made in a range of 0,2-1.3, preferably 0.25-1.0.</p> |
