Patent ID: 8240481

Claim:
A stand-alone sifter comprising: a receiver having a supply chamber and designated to receive powder to be sifted; an inlet connected to said receiver and configured to introduce to said receiver by pouring or dropping the powder to be sifted; a sieve assembly having a sieving chamber, said sieving chamber having an inner area and an outer area, said sieve assembly being coupled to and communicating with said supply chamber; a rotor having a rotating shaft laterally arranged to pass through said supply chamber and said sieving chamber; a cylindrical sieve located inside said sieving chamber and arranged coaxially with said rotating shaft; a hollow drum having an inner circumferential face and an outer circumferential face, having a circular cross-section, and having a larger diameter than the diameter of said rotating shaft, said hollow drum being extended in at least space of said sieving chamber and arranged coaxially with said cylindrical sieve in an axial direction of said rotating shaft, and said hollow drum having a front end extending from said inner area of said sieving chamber inside said cylindrical sieve to said supply chamber; a stirring rotor located in said inner area of said sieving chamber inside said cylindrical sieve, said stirring rotor comprising a plurality of rotating blades attached to said rotating shaft to push the powder to be sifted from said inner area to said outer area of said sieving chamber outside said cylindrical sieve, said stirring rotor being attached to said outer circumferential face of said hollow drum; an extraction member for enabling removal of oversize powder or foreign substances trapped by said cylindrical sieve from said inner area; and an outlet for discharging powder passing through said cylindrical sieve from said inner area to said outer area, wherein a paddle for moving said powder from said supply chamber to said sieving chamber is attached to said rotating shaft in said supply chamber; and a ratio of an outer diameter of said hollow drum to an inner diameter of said sieve is between 40 and 85%.