VERTICAL SCREENING DEVICE

Abstract: Vertical screening device (1) having at least one cylinder screen (2) and connectible with its lower end portion (8) to a similar screening device or a drive unit and, with its upper end portion (7), to a similar screening device or a distributor device. The screening device is adapted, together with the other devices connected to it, to be imparted a movement of rotation. The invention is characterized in that the screening device (1) comprises a bearing device (3) for a feed screw (4) cooperating with the cylinder screen (2). The bearing device (3) is disposed within the cylinder screen (2) and fixedly connected thereto. The feed screw (4) is connected through a link (5) extending outside the periphery of the cylinder screen (2), to a fixed point (6) provided outside the screening device (1) for holding the feed screw (4) still.

Description: VERTICAL SCREENING DEVICE The present invention relates to a vertical screen¬ ing device having at least one cylinder screen, said screeening device being adapted to be connected with its lower end portion to a similar screening device or a drive unit and, with its upper end portion, to a similar screening device or a distributor device, said screening device further being adapted, together with the other devices connected thereto, to be im¬ parted a movement of rotation. The screening device may thus be of the type disclosed in Swedish Patent 434,349, although it must not necessarily be imparted an oscillating angular velocity. The screening device is so designed that it can be removed laterally once the connection with the other devices has been undone. The novel features of the invention reside in that the screening device comprises a bearing device for a feed screw cooperating with the cylinder screen, said bearing device being disposed within the cylinder screen and fixedly connected thereto, and said feed screw being connected through a link extending outside the periphery of the cylinder screen, to- a fixed point provided outside the screening device for holding the feed screw still. The advantage of a stationary feed screw is that the screening material to be fed is imparted a predetermined feed rate, and that the material moves helically downwards in the cylinder screen. This means improved distribution and mixing of the screening material. Thus, the present invention has made it possible to use a stationary feed screw in the screening device contemplated. The invention will be described in more detail hereinbelow with reference to the accompanying drawings showing, by way of example only, one embodiment of the screening device. Fig. 1 shows the screening device in vertical cross-section. Fig. 2 shows the bearing device in vertical cross-section. Fig. 3 shows the bearing device from above. Fig. 4 is a section taken along the line A-A in Fig. 2, and Fig. 5 is a top plan view showing the link with the parts associated therewith. The screening device 1 comprises a bearing device 3, disposed within the cylinder screen 2 and fixedly connected thereto, for a feed screw 4 cooperating with the cylinder screen 2 and connected through a link 5 extending outside the periphery of the cylinder screen 2 , to a fixed point 6 provided outside the screening device 1 for holding the feed screw 4 sta¬ tionary. More specifically, the fixed point 6 is lo- cated at a fixed outer cylinder disposed outside the screening device 1. The bearing device 3 for the feed screw 4 con¬ stitutes a fixed connection for transmitting rotational and torsional forces, between the upper and lower end portions 7 and 8, respectively, of the screening device 1, which suitably consist of flanges. The cy¬ linder screen 2 is however fixedly connected to only one end portion 7 r there being a space defined between the cylinder screen 2 and the other end portion 8. This space is used for the link 5 of the feed screw 4. The link 5 of the feed screw 4 is fixed to a flange 9 fixedly connected to the feed screw 4 and located opposite the end flange 8 and opposite a cor¬ responding flange 10 on the cylinder screen 2. Sealing means 11 are provided between the flanges 8, 9 and 10. As seen in the drawings, the sealing means 11, here being brushes, are mounted on the flange 9 so as to engage the flanges 8 and 10. As appears from Fig. 5, the link 5 is fixed to the outer side of the flange 9 outwardly of the sealing means 11, whereby the link 5 will in no way interfere therewith. The bearing device 3 comprises a cylindrical tube 12 which is lower than the screening device 1. The feed screw 4 is mounted around the tube 12 by means of a substantially equally high tubular cen- tral body 13, while the screw 14 itself extends with a fully open part above the tubular central body 13. The body 13 suitably consists of a thin-walled steel cylinder on the outer side of which a steel helix forming the screw 14 proper is wound and fixed by welding. A rubber helix 15 is fixed to the underside of the steel helix 14. The tubular central body 13 is provided on its inside with rollers 16 and 17 which for guiding the screw 4 in both the radial and the axial sense, are adapted to roll on tracks 18 and 19 provided at the outer side of the cylindrical tube 12 of the bearing device 3. The rollers 16, guiding the screw 4 radially, are suitably six in number and evenly distributed pairwise along the periphery, while the rollers 17, guiding the screw 4 axially, are suitably four in number and pairwise diametrically disposed. The tracks 18 and 19 preferable consist of plastic rings. As best seen in Fig. 2, the bearing device 3 comprises a number of axially extending rods 20 which are disposed above the cylindrical tube 12 and evenly distributed along the inner periphery of the feed screw 4. Further, between the cylindrical tube 12 and the axially extending rods 20 there is provided a radial plate 21. By this arrangement and by the bearing device 3 being directly or indirectly connected to the flanges 7 and 8 at its upper and lower portions, the bearing device 3 serves to transmit rotational and torsional forces between the flanges 7 and 8. At its lower end, the cylinder screen 2 is provided with an inwardly directed cone 22 guiding the screening material so that it will not unecessarily interfere with the brushes serving as sealing means 11. The interconnection of two screening devices 1 according to the invention can be brought about by connecting the flange 7 of one device directly to the flange 8 of the other device. As in the patent mentioned above, use may however be made of a flanged ring or the like as coupling means. The invention is not restricted to the embodiment described above and illustrated in the drawings, but may be modified within the spirit and scope of the accompanying claims.

Claims: CLAIMS 1. A vertical screening device having at least one cylinder screen, said screening device (1) being adapted to be connected with its lower end portion (8) to a similar screening device or a drive unit and, with its upper end portion (7 ), to a similar screen¬ ing device or a distributor device, said screening de¬ vice (1) further being adapted, together with the other devices connected thereto, to be imparted a movement of rotation, c h a r a c t e r i z e d in that the screening device (1) comprises a bearing device (3) for a feed screw (4) cooperating with the cylinder screen (2), said bearing device being disposed within the cylinder screen (2) and fixedly connected there¬ to, and said feed screw (4) being connected through a link (5) extending outside the periphery of the cylinder screen (2), to a fixed point (6) provided outside the screening device (1) for holding the feed screw (4) still. 2. Vertical screening device as claimed in claim 1, c h a r a c t e r i z e d in that the bearing device (3) for the feed screw (4) constitutes a fixed con¬ nection transmitting rotational and torsional forces between the upper (7) and lower (8) end portions, suitably consisting of flanges, of the screening de- vice (1), while the cylinder screen (2) is fixedly connected only to one end portion (7), a space being provided between the cylinder screen (2) and said other end portion (8) for said link (5) of the feed screw (4 ) . 3. Vertical screening device as claimed in claim 2, c h a r a c t e r i z e d in that the link (5) of the feed screw (4) is fixed to a flange (9) fixedly con¬ nected to the feed screw (4) and located opposite the flange (8) forming said other end portion of the screen- ing device (1), and opposite a corresponding flange (10) on the cylinder screen (2), there being provided sealing means (11) between said three flanges (8-10). 4. Vertical screening device as claimed in claim 2 or 3, c h a r a c t e r i z e d in that the bearing device (3) for the feed screw (4) comprises a cylin¬ drical tube (12) which is lower than the screening device (1) and around which the feed screw (4) is mounted by means of a substantially equally high tubu- lar central body (13), the feed screw (4) extending with a fully open part above said tubular central body (13). 5. Vertical screening device as claimed in claim 4, c h a r a c t e r i z e d in that the tubular central body (13) of the feed screw (4) is provided on its inner side with rollers (16, 17) which, for guiding the screw (4) both radially and axially, are adapted to roll on tracks (18, 19) provided at the outer side of the cylindrical tube (12) of the bearing device (3). 6. Vertical screening device as claimed in claim 5, c h a r a c t e r i z e d in that the bearing device (3) for the feed screw (4) comprises a number of axially extending rods (20) disposed above the cylindrical tube (12) and evenly distributed along the inner periphery of the feed screw ( ) . 7. Vertical screening device as claimed in claim 6, c h a r a c t e r i z e d in that the bearing device (3) is- provided with a radially extending plate (21) between the cylindrical tube (12) and the axially extending rods (20).

Inventors: ANDREN INGMAR, ANDREN, INGMAR
Applicants: LINDEMA KB
Application year: 1987
Main classification: B07B1
IPC codes: B07B1