Continuous filtering process and an apparatus therefor

Claim 1

A continuous filtering process comprising the steps of: a. admixing fluid to be filtered with a predetermined amount of solid particles which can remove free impurities in the fluid by adsorption, absorption, promotion of a decomposition reaction or the like when the particles become in contact with such free impurities; b. permitting said solid particles to remove free impurities in the fluid by adsorption, absorption, promotion of decomposition or the like, c. continuously flowing the fluid to be filtered having been admixed with said solid particles through an inlet of a filter tank having therein i. a plurality of hollow filter disks fixedly arranged with equal intervals therebetween, ii. facing filter media supported on the filter disks, and iii. a plurality of rotators, each rotator being positioned between two adjacent filter disks with small clearances between the surfaces of the rotator and the surfaces of the filter media on the filter disks, d. rotating the rotators continuously with a predetermined speed of rotation to cause a violent turbulence of the fluid to be filtered and thereby causing motion of the solid particles on the surfaces of the filter media, removing a layer of concentrated fluid from the surfaces of the filter media by said violent turbulence of the fluid and by motion of the solid particles, and achieving filtration through the filter media without substantial impurities adhering on the surfaces of the filter media; e. continuously withdrawing filtrate from within the hollow filter disks; f. continuously withdrawing fluid to be filtered from an outlet of the filter tank to an inlet end of an agitation tank having agitation means therein and agitating the fluid within the agitation tank, g. supplying fresh fluid to be filtered to said inlet end of the agitation tank at a rate substantially equal to the rate of withdrawing said filtrate from the filter disks; h. agitating the fluid in the agitation tank; i. continuously withdrawing fluid from an outlet end of the agitation tank, the outlet end of the agitation tank being spaced from the inlet end to provide the fluid within the agitation tank with a stay time and agitation by means of the agitation means whereby the concentration of free impurities in the said fluid is lowered to a concentration that is substantially equal to the concentration of free impurities in the fresh fluid to be filtered; and j. continuously supplying the fluid withdrawn from the outlet end of the agitation tank to the inlet of the filter tank.