Patent ES-8501257-A3 (ES)
Title: Rotatable drum for separating bulk material
IPC: B07B4/06
Filed: 1984-01-25
Abstract: A separation drum for bulk material is rotatable about its longitudinal axis and traversed by an air flow. A zone is defined between discharge apertures for heavier and lighter fractions of the material and has inwardly-directed spirals on the inside of the drum. Lifting members are arranged in the thread turns between the spirals and act as barriers to the bulk material. The members are arranged in groups. In use, the lighter fraction is blown further forward by the air flow so that forward feed is much greater than rearward feed in the thread turns. - Used for sepn. of chopped harvested crops which contain a mixt. of grains and straw. Effective sepn. is carried out since the rearwards feed of the grains is about 1.5 times greater than the forward feed and the forward feed of the straw is several times greater than its rearward feed. EPAB- EP--79357 B Drum (2) with at least one section for separation of a bulk material into a heavier and a lighter fraction, which drum (2) is arranged to rotate around its central axis (16) at a certain velocity and to be traversed by a flow of air at a certain flow velocity, besodes which the drum (2) exhibits at least one discharge aperture (13) for the heavier fraction and at least one discharge aperture (25) for tie lighter fraction located further away in the drum (2), viewed in the direction of air flow, and wherein the drum (2) in at least one section thereof between the said discharge aperture (13) for the heavier fraction and the said discharge aperture (25) for the lighter fraction is provided with rearward-feeding transport members in the form of inwardly directed spirals (27) fastened to the inside the drum (2) and arranged so that during rotation of the drum (2) they transport material in the thread turns (28) between the spirals (27) to the rear towards the said discharge aperture for the heavier fraction, and also lifters (29,30) for the bulk material arranged in all thread turns (28) and designed as barriers against continued rearward feed of the bulk material, each of said lifters (29,30) interconnecting two adjacent spirals (27), characterised in that the lifting surface of each of said lifters (29, 30) forms an obtuse angle with the first of the two adjacent spirals (27) as viewed in the direction of the air flow and an acute angle with the second of said two spirals (27), which lifters (29,30) are arranged in groups (I-XI) along the said section around the inside of the drum (2), each group (I-XI) consisting of all of a plurality of lifters (29,30) that lie along a circumferential line (I-XI) defined by a transverse section of the drum (2), and where in each such group (I-XI) a plurality of the thread turns (28), but not all, contain lifters (29,30), and that the axial distance (L) between at least the majority of adjacent circumferential lines (I-XI), i.e. the p - EP--79357 B Drum (2) with at least one section for separation of a bulk material into a heavier and a lighter fraction, which drum (2) is arranged to rotate around its central axis (16) at a certain velocity and to be traversed by a flow of air at a certain flow velocity, besodes which the drum (2) exhibits at least one discharge aperture (13) for the heavier fraction and at least one discharge aperture (25) for tie lighter fraction located further away in the drum (2), viewed in the direction of air flow, and wherein the drum (2) in at least one section thereof between the said discharge aperture (13) for the heavier fraction and the said discharge aperture (25) for the lighter fraction is provided with rearward-feeding transport members in the form of inwardly directed spirals (27) fastened to the inside the drum (2) and arranged so that during rotation of the drum (2) they transport material in the thread turns (28) between the spirals (27) to the rear towards the said discharge aperture for the heavier fraction, and also lifters (29,30) for the bulk material arranged in all thread turns (28) and designed as barriers against continued rearward feed of the bulk material, each of said lifters (29,30) interconnecting two adjacent spirals (27), characterised in that the lifting surface of each of said lifters (29, 30) forms an obtuse angle with the first of the two adjacent spirals (27) as viewed in the direction of the air flow and an acute angle with the second of said two spirals (27), which lifters (29,30) are arranged in groups (I-XI) along the said section around the inside of the drum (2), each group (I-XI) consisting of all of a plurality of lifters (29,30) that lie along a circumferential line (I-XI) defined by a transverse section of the drum (2), and where in each such group (I-XI) a plurality of the thread turns (28), but not all, contain lifters (29,30), and that the axial distance (L) between at least the majority of adjacent circumferential lines (I-XI), i.e. the p USAB- US4549660 A A drum separator for sepg. a bulk particulate material into heavy and light fractions, comprises a hollow, cylindrical drum rotatable about a horizontal axis, an inlet for the bulk material, an outlet at the rear of the drum for discharging the heavy fraction, and an outlet at the front for discharging the light fraction. Air passes through the drum from near to front. Inwardly directed spirals are fastened to the inside of the drum for transporting material towards the rear of the drum. Lifters in the form of groups of barriers are located between the thread turns of the spirals, for dropping material across the air flow upon rotation of the drum. The spirals transport the heavy material to the rear, while the air flow blows the lighter fraction to the front.