Method and apparatuses for pre-screening

Abstract

A vibratory screening machine includes a primary screening area and a pre-screening assembly including a frame and screen assemblies. The screen assemblies are secured to the frame and form a pre-screening surface. The frame is attached to the vibratory screening machine such that the concave pre-screening surface is above the primary screening area.

Claims

1. A pre-screening assembly for a vibratory screening machine, comprising: a frame; and multiple screen assemblies, the frame including a central spine and ribs, the ribs form a concave support surface for the multiple screen assemblies, the central spine is configured to attach to a central member of the vibratory screening machine, the multiple screen assemblies secured to the frame and arranged together to form a concave pre-screening surface that screens a material before the material reaches a primary screening surface of the vibratory screening machine.

2. The pre-screening assembly recited in claim 1, further comprising a screen assembly attachment arrangement configured to secure the multiple screen assemblies to the frame.

3. The pre-screening assembly recited in claim 1, wherein the frame includes at least one of a rigid and a semi-rigid portion.

4. The pre-screening assembly recited in claim 1, wherein vibrations are isolated to the pre-screening assembly through the central spine.

5. The pre-screening assembly recited in claim 4, wherein the screen assemblies include horizontal portion screen assemblies and vertical portion screen assemblies and the ribs include horizontal and vertical rib portions, the horizontal rib portions extending substantially perpendicular to the spine, the vertical rib portions extending substantially perpendicular to the horizontal rib portions, wherein the horizontal portion screen assemblies and vertical portion screen assemblies are arranged on the horizontal and vertical rib portions, respectively.

6. The pre-screening assembly recited in claim 1, wherein the frame is elongated, the central spine and the ribs extending substantially the length of the frame.

7. The pre-screening assembly recited in claim 1, further comprising a vibratory motor configured to vibrate at least one of the pre-screening assembly or the primary screening surface.

8. The pre-screening assembly recited in claim 1, wherein the primary screening surface includes a first primary screening area and a second primary screening area, the central member located between the first primary screening area and the second primary screening area.

9. The pre-screening assembly recited in claim 1, wherein the multiple screen assemblies include a first substantially vertical screen assembly that is at an angle of about 10 to about 80 relative to a first substantially horizontal screen assembly and a second substantially vertical screen assembly that is at an angle of about 170 to about 100 relative to a second substantially horizontal screen assembly.

10. The pre-screening assembly recited in claim 1, wherein the primary screening area includes a concave screening surface.

11. The pre-screening assembly recited in claim 1, wherein the vibratory screening machine includes a central member that divides the primary screening surface into a first concave screening surface and a second concave screening surface.

12. The pre-screening assembly recited in claim 1, further comprising a screen assembly attachment arrangement configured to secure the multiple screen assemblies to the frame.

13. The pre-screening assembly recited in claim 1, wherein the multiple screen assemblies include a first screen assembly configured to form a predetermined shape when pressed against a portion of the frame, and a second screen assembly located opposite the first screen assembly, the second screen assembly configured to form a predetermined shape when pressed against an opposite side of the portion of the frame, the first screen assembly and the second screen assembly forming a section of the concave pre-screening surface.

14. The pre-screening assembly recited in claim 1, wherein the vibratory screening machine includes a central member that divides the primary screening area into two screening areas, and the frame includes a central spine attached to the central member, and vibrations are imparted from the vibratory screening machine to the frame primarily through the central member.

15. The pre-screening assembly recited in claim 14, wherein the vibrations are transferred from the vibratory screening machine to the frame exclusively from the central member to the central spine.

16. The pre-screening assembly recited in claim 1, wherein the vibratory screening machine includes first and second sidewalls and the frame is located between and spaced away from the first and second sidewalls.

17. A method for screening materials, the method comprising: pre-screening a material using a pre-screening assembly having multiple screen assemblies configured to form a concave pre-screening surface, the pre-screening assembly secured to a vibratory screening machine and positioned above a primary screening surface, the pre-screening assembly including an elongated member that attaches to a central structural member of the vibratory screening machine independently of a sidewall of the vibratory screening machine.

18. The method recited in claim 17, further comprising vibrating at least one of the pre-screening assembly or the vibratory screening machine.

19. The method recited in claim 17, wherein the pre-screening assembly includes a frame, and further comprising securing the screen assemblies to the frame; unsecuring the screen assemblies; removing the screen assemblies; and replacing the screen assemblies.

20. A pre-screening assembly, comprising: a frame; and screen assemblies, the frame including a central spine that is configured to attach to a central member of a vibratory screening machine, and further includes ribs extending from the central member forming a concave support surface, the screen assemblies secured to the frame forming a concave pre-screening surface, wherein the screen assemblies are further secured to the concave support surface.

21. The pre-screening assembly recited in claim 20, further comprising a screen assembly attachment arrangement configured to secure the screen assemblies to the frame.

22. The pre-screening assembly recited in claim 20, wherein the frame includes at least one of a rigid portion or a semi-rigid portion.

23. The pre-screening assembly recited in claim 20, wherein the screen assemblies include horizontal portion screen assemblies and vertical portion screen assemblies and the ribs include horizontal and vertical rib portions, the horizontal rib portions extending substantially perpendicular to the spine, the vertical rib portions extending substantially perpendicular to the horizontal rib portions, wherein the horizontal portion screen assemblies and vertical portion screen assemblies are arranged on the horizontal and vertical rib portions, respectively.

24. The pre-screening assembly recited in claim 20, wherein the frame is elongated, the central spine and the ribs extending substantially the length of the frame.

25. The pre-screening assembly recited in claim 20, further comprising a vibratory motor, wherein the vibratory screening machine includes a primary screening surface, the vibratory motor configured to vibrate at least one of the pre-screening assembly and the primary screening surface.

26. The pre-screening assembly recited in claim 20, wherein the screen assemblies include a first substantially vertical screen assembly that is at an angle of about 10 to about 80 relative to a first substantially horizontal screen assembly and a second substantially vertical screen assembly that is at an angle of about 170 to about 100 relative to a second substantially horizontal screen assembly.

27. The vibratory screening machine recited in claim 20, wherein the screen assemblies include a first screen assembly configured to form a predetermined shape when pressed against a portion of the frame, and a second screen assembly located opposite the first screen assembly, the second screen assembly configured to form a predetermined shape when pressed against an opposite side of the portion of the frame, the first screen assembly and the second screen assembly forming a section of the concave pre-screening surface.

28. The pre-screening assembly recited in claim 20, wherein the central member divides the primary screening area into two screening areas, and wherein the central spine attaches to the central member and vibrations are imparted from the vibratory screening machine to the frame primarily through the central member.

29. The pre-screening assembly recited in claim 28, wherein the vibrations are transferred from the vibratory screening machine to the frame exclusively from the central member to the central spine.

30. The pre-screening assembly recited in claim 20, wherein the concave pre-screening surface is curved.

31. The pre-screening assembly recited in claim 20, wherein the concave pre-screening surface is formed by multiple flat surfaces.

32. The pre-screening assembly recited in claim 20, wherein the vibratory screening machine includes first and second sidewalls and the frame is located between and spaced away from the first and second sidewalls.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a perspective view of a vibratory screening machine with an installed pre-screening assembly according to an example embodiment of the present invention.

(2) FIG. 2 shows a perspective view of the vibratory screening machine shown in FIG. 1.

(3) FIG. 3 shows a perspective view of the vibratory screening machine shown in FIG. 1.

(4) FIG. 4 shows a perspective view of the vibratory screening machine shown in FIG. 1.

(5) FIG. 5 shows a front view of the vibratory screening machine shown in FIG. 1 without a feeder.

(6) FIG. 6 shows a side view of the vibratory screening machine shown in FIG. 1.

(7) FIG. 7 shows a perspective view of a pre-screening assembly according to an example embodiment of the present invention.

(8) FIG. 8 shows a perspective view of a screen assembly according to an example embodiment of the present invention.

(9) FIG. 9 shows a perspective view of a frame of a pre-screening assembly according to an example embodiment of the present invention.

(10) FIG. 10 shows a perspective view of the frame shown in FIG. 9 with installed screen assemblies.

(11) FIG. 11 shows a perspective view of the frame shown in FIG. 9 attached to a vibratory screening machine.

(12) FIG. 12 shows a perspective view of pre-screening assembly shown in FIG. 10.

(13) FIG. 13 shows a cross-sectional view of a pre-screening assembly according to an example embodiment of the present invention.

(14) FIG. 14 shows a perspective view of a pre-screening assembly according to an example embodiment of the present invention.

(15) FIG. 15 shows a cross-sectional view of pre-screening assemblies according to an example embodiment of the present invention.

(16) FIG. 16 shows a cross-sectional view of pre-screening assemblies according to an example embodiment of the present invention.

(17) FIG. 17 shows a cross-sectional view of a pre-screening assembly according to an example embodiment of the present invention.

(18) FIGS. 18 to 20 show a cross-sectional view of the removal of a screen assembly according to an example embodiment of the present invention.

(19) FIG. 21 shows a partial cross-sectional view of a pre-screening assembly according to an example embodiment of the present invention.

(20) FIG. 22 shows a perspective view of pre-screening assemblies according to an example embodiment of the present invention.

DETAILED DESCRIPTION

(21) Like reference characters denote like parts in the drawings.

(22) FIG. 1 shows a vibratory screening machine 10 with an installed pre-screening assembly 20. Material is fed into a feeder 100 and then directed onto a concave screening surface 30 of pre-screening assembly 20. Screen assemblies 50 form concave screening surface 30. Undersized material passes through screening surface 30 and onto a primary screening surface 110. Oversized materials are discharge from end 40 of pre-screening assembly 20. Material travels in flow direction 120 toward the vibratory screening machine 10 end 140. The material flowing inside pre-screening assembly 20 is contained within concave screening surface 30. The material may be dry, a slurry, etc.

(23) Vibratory screening machine 10 includes wall members 12, a central member 16 and an acceleration arrangement 18. Central member 16 divides vibratory screening machine 10 into two screening areas. Vibratory screening machine 10 may, however, have one or more concave screening areas.

(24) FIG. 2 shows the vibratory screening machine shown in FIG. 1 without feeder 100 and without installed screen assemblies 50. Pre-screen assembly 20 includes a frame 21 that includes a central spine 52, ribs 54, horizontal portions 56, vertical portions 58 and a bar 62. Frame 21 has a general hull type shape but may be configured in other arrangements suitable for pre-screening materials. Frame 21 is configured to provide a generally concave surface to support screen assemblies 50. Pre-screen assembly 20 also includes screen assembly attachment arrangements 60 configured to secure screen assemblies 50 to frame 21. Screen assembly attachment arrangements 60 are pre-tensioned spring clamps but may also include other screen securing mechanisms such as mechanical, electromechanical, pneumatic or hydraulic systems.

(25) FIG. 3 shows the vibratory screening machine 10 without a feeder 100 and without installed screen assemblies 50 and without primary screening surfaces 110.

(26) FIG. 4 shows vibratory screening machine 10 with screen assemblies 50.

(27) FIG. 5 shows vibratory screening machine 10 with pre-screening assembly 20. Pre-screening assembly 20 includes frame 21 and screen assemblies 50.

(28) FIG. 6 shows vibratory screening machine 10.

(29) FIG. 7 shows pre-screening assembly 20 with labeled parts.

(30) FIG. 8 shows screen assembly 50. Screen assembly 50 includes screen 70 and screen frame members 72. Screen 70 is a mesh screen but may be any type of screen and may include multiple layers. The layers may be mesh and/or other materials. The screen frame members are plate members but may be any type of structural member including tubing, formed flanges, etc. Screen 70 is attached to the screen frame members 72 by gluing but may be attached by mechanical fastening, welding, etc. Screen assembly 50 is configured to be easily secured to and removed from frame 21. Accordingly, screen assembly may be provided in operator friendly sizes and weights.

(31) The screen assemblies may also be molded, cast or welded and may be formed as a single unit. The screen assemblies may be provided with a coating such as a polyurethane or other suitable material for handling and wear resistance.

(32) FIG. 9 shows frame 21. Frame 21 includes central spine 52, substantially horizontal portions 56, substantially vertical portions 58, longitudinal spacing elements 74, bar 62 and flange 76. Flange 76 provides for attachment of frame 21 to feeder 100. Also shown are pre-tension spring clamps 60.

(33) FIG. 10 shows frame 21 with installed screen assemblies 50. Screen assemblies 50 are clamped in place by pre-tension spring clamps 60. Separate screen assemblies 50 are provided on the substantial horizontal portions 56 and substantially vertical portions 58. Portions 56 and 58 may provide other surface configurations for screen assemblies 50, including different angled or contoured formations. Pre-tension spring clamps 60 push against an edge of the screen assemblies 50 (which are in a substantially vertical position). These substantially vertical screen assemblies 50 push against the substantially horizontal screen assemblies 50 which contact bar 62 thereby snugly securing screen assemblies 50 in place. As is shown in FIGS. 18 to 20, screen assemblies 50 are easily replaceable.

(34) FIG. 11 shows frame 21 arranged on vibratory screening machine 10. Frame 21 may have additional support members 212 that provide for additional stability with respect to vibratory screening machine 10. The additional support members 212 may be provided in different configurations including configurations structured to provide maximum vibrations from vibratory screening machine 10.

(35) FIG. 12 shows pre-screening assembly 20 arranged on vibratory screening machine 10. Pre-screening assembly 20 includes screen assemblies 50.

(36) FIG. 13 shows pre-screening assembly 20 with frame 21, screen assemblies 50, bar 62, horizontal portions 56 and vertical portions 58. Screen assemblies 50 form a concave screening surface and bar 62 forms a keel like spine at the bottom of the concave screening surface.

(37) FIG. 14 shows frame 21 with ribs 54 and central spine 52. Ribs 54 provide for horizontal and vertical inner surfaces 80 and 82, respectively. The ribs are spaced along the keel like spine 52.

(38) FIG. 15 shows a pre-screening arrangement 300 that includes three pre-screening assemblies 20 placed side by side. The pre-screening assemblies 20 are located above primary screening surface 110 and attached to vibratory screening machine 10 by member 52. Although three pre-screening assemblies 20 are shown multiple pre-screening assemblies may be provided. Additionally, pre-screening assemblies 20 may be secured to each other such that they form a connecting network. Each pre-screening assembly 20 has a concave screening surface. Alternative configurations may be structured such that different screening surfaces profiles are provided.

(39) FIG. 16 shows pre-screening arrangement 400. Pre-screening arrangement 400 includes three pre-screening assemblies 20 arranged one above another. The top two pre-screening assemblies 20 include a bar 62 and an elongated member or spine 86. Elongated members 86 attach pre-screening assemblies 20 to the bar 62 of the pre-screening assembly 20 below it. The top two pre-screening assemblies 20 also include deflector arrangements 84 located on their lower surfaces. Deflector arrangements 84 direct material passing through the pre-screening assemblies 20 outward beyond the side plane of the framework beneath. Although three pre-screening assemblies 20 are shown, two or more pre-screening assemblies may be provided in such a vertical configuration. Additionally vertical arrangements may also be provided.

(40) FIG. 17 shows a pre-screening assembly 500. Pre-screening assembly 500 includes two screen assemblies 550 positioned such that one side is in contact with locating bar 562 and another side if fastened by a screen assembly attachment arrangement (which may include attachment arrangements as described above) such that screen assemblies are formed into a concave shape including curved surfaces. Although two screen assemblies 550 are shown multiple screen assemblies 550 may be provided.

(41) FIGS. 18 to 20 show the removal of a screen assembly 50 from a pre-screening assembly 20. Pre-screening assemblies 20 include pre-tension spring clamps 60 that secure screen assemblies 50 against bar 62. Pre-tension spring clamps 60 include a leaf spring 90 that applies a force to an edge of screen assemblies 50 pushing screen assemblies 50 against bar 62. Pre-tension spring clamps 60 are attached to frame 21 and include a notched fulcrum 92 and spring pull off 94. When member 96 is placed on notched fulcrum 92 and in spring pull off 94 and pushed downwardly in direction 97 leaf spring 90 is lifted off the edge of screen assembly 50 and screen assembly 50 may be removed. When the downward pressure is taken off member 96 leaf spring 90 returns to its original position. As described above, alternative screen assembly attachment arrangements may be provided.

(42) FIG. 21 shows pre-screening assembly 20 and pre-tension spring clamp assembly 60 with labeled parts.

(43) FIG. 22 shows pre-screening assemblies 20 in a side by side arrangement with a common flange 99 for attachment to a feeder. Although two pre-screening assemblies 20 are shown multiple pre-screening assemblies 20 may be provided.

(44) A method for screening materials includes attaching a pre-screen assembly to a vibratory screen machine, the pre-screen assembly including an elongated spine and concave screening surface, pre-screening material on the concave screening surface and screening material on a primary screening surface. The method may also include vibrating the pre-screen assembly, accelerating the screen assembly, returning the screen assembly to its original shape and replacing the screen assembly with another screen assembly.

(45) In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense.