초록 ▼

A classifier for particulate material of the type wherein a stream of the particles to be classified is introduced into a moving stream of air, classification being achieved by the varying degree of entrainment of the particles in the air stream due to their difference in size. The classifier employ

A classifier for particulate material of the type wherein a stream of the particles to be classified is introduced into a moving stream of air, classification being achieved by the varying degree of entrainment of the particles in the air stream due to their difference in size. The classifier employs a closed housing having a plurality of outlets, each for a different size of particle, and an inlet located thereabove. An air impeller drives a current of air across the particle outlets. The housing is closed so that the air defining the stream is continuously recirculated. At a point in the air stream downstream of the outlets there is provided an enlarged chamber through which the air flows at an extremely low velocity to preclude particles from being entrained in the air to be carried back to the air impeller.

대표청구항 ▼

Air classifying apparatus for particulate material comprising: a generally horizontally elongated, substantially closed housing having an upper side, a bottom side, a pair of side walls, and means defining end walls; means in said bottom wall intermediate the ends thereof defining a plurality of ind

Air classifying apparatus for particulate material comprising: a generally horizontally elongated, substantially closed housing having an upper side, a bottom side, a pair of side walls, and means defining end walls; means in said bottom wall intermediate the ends thereof defining a plurality of individual particle outlets, said outlets extending transversely of said housing and being arranged serially in the direction of elongation thereof; an air impelling device located within said housing adjacent one end thereof and operable to direct air from said one end toward the other end across said particle outlets; a particulate material inlet within said housing including an elongated metering orifice within said housing extending transversely of said housing through which particulate material may be introduced into said housing, said orifice being located directly above or upstream of the particulate outlet nearest said housing one end so that particulate material flowing therefrom will be entrained in a current of air generated by said air impelling device with the heavier particles dropping more directly downwardly under the influence of gravity than the lighter particles; means downstream of said impeller and upstream of said orifice for establishing a laminar air flow characteristic in the current of air generated by said air impeller prior to the impingement of said current of air on a stream of particles emanating from said orifice; light particle directing means within said housing for directing extremely light particles entrained in said current of air toward at least the particle outlet nearest the other end of said housing; and said housing including an enlarged chamber downstream of said particle outlet nearest said other end, said chamber being sufficiently large that a current of air passing therethrough is at a relatively low velocity to substantially preclude particles entrained in said current of air from passing through said chamber; means associated with said chamber for directing particles entrained in air reaching said chamber toward one of said particle outlets; and means associated with said chamber for redirecting air therefrom toward said air impelling device to define a closed air circulation path.