Shale shaker basket system

Abstract

A basket system for a shale shaker includes a front, solids discharge end and a rear, feed end, spaced apart by opposed first and second sides. The feed end includes a fluid retaining wall. A first screen deck frame is mounted or mountable to the basket for supporting a screening surface and forming a first screen deck in use. The screening surface of the first screen deck has a lower, feed receiving end that is proximal to the fluid retaining wall at the rear end of the basket and a distal, higher, solids discharge end at the front end of the basket. The basket further includes at least one mounting for mounting at least one additional screen deck frame above or below the first screen deck frame.

Claims

1. A basket system for a shale shaker, wherein the basket comprises: a front, solids discharge end and a rear, feed end, spaced apart by opposed first and second sides, wherein the feed end includes a fluid retaining wall; a lower screen deck frame mounted or mountable to the basket for supporting a lower screening surface and forming a lower screen deck in use, whereby the screening surface of the lower screen deck has a lower, feed receiving, end that is proximal to the fluid retaining wall at the rear end of the basket and a distal, higher, solids discharge end at the front end of the basket; wherein the fluid retaining wall includes a feed director extending rearwards and formed for directing an applied solids and liquid feed towards the front of the basket and onto the lower screen deck; and wherein the basket further includes a mounting for mounting at least one upper screen deck frame above the lower screen deck frame; and a mounting for a cover plate releasably attachable to the fluid retaining wall to cover the location for the feed director on the fluid retaining wall; and wherein the system further includes at least one upper screen deck frame and at least one cover plate; the cover plate comprises a mounting for mounting at least one upper screen deck frame above the lower screen deck frame.

2. The basket system of claim 1 wherein the fluid retaining wall is provided with an aperture for mounting or an aperture mounting the feed director; the feed director when mounted extending rearwards of the aperture and formed for directing a solids and liquid feed applied into the aperture towards the front of the basket and onto the lower screen deck.

3. The basket system of claim 2 wherein the feed director takes the form of a blister on the aperture of the fluid retaining wall.

4. The basket system of claim 3 wherein the blister seals to around the periphery of the aperture.

5. The basket system of claim 2 wherein the feed director is a deflector plate or trough that receives a solids and liquid feed from outside the rear wall of the basket and directs the feed forwards through the aperture towards the lower screen deck.

6. The basket system of claim 2 wherein the feed director of the fluid retaining wall is a rearwards extending deviation or bulge in the shape of the fluid retaining wall.

7. The basket system of claim 1 wherein the cover plate comprises mountings for mounting two or more upper screen deck frames, one above the other, to form a stack of screen deck frames above the lower screen deck frame.

8. The basket system of any one of claim 1 wherein the cover plate comprises one or more flanges projecting towards the front end of the basket to which a screen deck frame may be fitted with releasable fastenings.

9. The basket system of claim 8, wherein at least one flange of the cover plate projects towards the front end of the basket and is downwards directed, providing a downwards directed surface for releasable connection to a front edge of a screen deck frame.

10. The basket system of claim 8, wherein the feed receiving end of each upper screen deck frame, when fitted, is spaced by the one or more flanges so as to be further away from the fluid retaining wall than the screen deck frame below.

11. The basket system of claim 8, wherein cover plate support flanges are provides on the sides of the basket.

12. The basket system of claim 2 wherein the feed director is permanently fixed in place.

13. The basket system of claim 2 wherein the feed director is releasably attachable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a multi deck shaker;

(2) FIG. 2a shows in schematic partial cross section the feed end of a shale shaker basket;

(3) FIG. 2b shows in schematic elevation the end of a shale shaker basket feed viewed from inside the basket;

(4) FIGS. 2c to 2e each show in schematic partial cross section the feed ends of a shale shaker basket; and

(5) FIGS. 3a and 3b each show in schematic partial cross section the feed ends of a shale shaker basket.

DETAILED DESCRIPTION OF DISCLOSED EXEMPLARY EMBODIMENTS

(6) FIG. 1 shows a prior art shale shaker basket 1 of the same type shown in WO2015/166282. The basket 1 has a rear, feed end 2 with a fluid retaining wall 3 that is the rear end of the basket. The front, solids discharge end of the basket 4 is spaced from the feed end 2 by sides 6. The basket has mounts 8 for springs (not shown) to allow the basket 1 to float on a base (also not shown) when driven by vibratory drive system 10.

(7) Visible at the front end of the basket is a stack of three closely spaced screen decks 11 including screen deck frames 12 and screening surfaces 14. Solids falling from the ends of screen decks 11 can be collected and distributed as desired via trough arrangement 15

(8) FIGS. 2a and 2b show in partial cross section and elevation the rear feed end 2 of a basket generally of the form shown in FIG. 1 but modified to be a basket system of the third aspect of the disclosure.

(9) As can be seen in FIG. 2, a lower screen deck frame 16 which mounts a screening surface in use is fixed to a flange 18 of the fluid retaining wall 3. This may be by bolts at 20 or by welding. The lower screen deck frame 16 is also fitted to rest and be secured to flanges 21 of the basket sides as can be seen in FIG. 2b, where the arcuate upper surface of the screen deck frame 16 can be seen. Frame members supporting or making up the arcuate surface in the conventional way are not shown in this figure for clarity. The lower screen deck frame 16 is angled upwards towards the solids discharge end 4 of the basket.

(10) The fluid retaining wall 3 that forms the rear wall of the basket in this example is provided with rectangular aperture 22. Fitted at aperture 22 is a feed director 24 in the form of a blister 26. Feed director 24 is fixed by bolts 25 in this example and so is releasably attached. As an alternative it could be welded in place. As suggested by arrow 28, a solids and liquid feed applied rearwards to aperture 22 will be deflected and returned forwards onto the screening surface of the lower screen deck (frame 16 and an associated screening surface). This action moderates the flow of feed onto the lower screen deck, providing improved screening and reducing wear on the screening surface.

(11) Also visible in FIGS. 2a and 2b are cover plate support flanges 30 for supporting cover plates as described below with reference to FIGS. 2d and 2e. The cover plate support flanges 30 have the location of their bolt holes indicated in these figures by short vertical lines 32.

(12) FIG. 2c shows a similar arrangement to that of FIG. 2a except that feed director is in the form of a trough 34 for directing a solids and liquids feed into the basket 1 from outside the fluid retaining wall 3, through aperture 22 and forwards to the lower screen deck as suggested by arrow 28.

(13) In FIG. 2d, a similar arrangement to that of FIG. 2a is shown except that the feed director has been removed and the aperture 22 is covered by cover plate 36. In this example the cover plate 36 is conveniently fitted to the outside of aperture 22, and may be mounted to the same bolt holes as used for the feed director. The feed director of FIGS. 2a and 2b could be left in place, instead of being removed. The feed director may be permanently welded in place. If so a similar plate could be fitted to the inside of the aperture 22 to cover it.

(14) Cover plate 36 mounts flange 38 projecting forwards and downwards to provide a mounting 40 for bolting on an upper screen deck frame 42 that sits above lower screen deck frame 16 and has an extreme end further away from the rear end of the basket 1 (fluid retaining wall 3) than the lower screen frame 16. Cover plate support flanges 30 support cover plate flange 38 and secure it by bolts 44.

(15) In this example the two screen deck frames 16 and 42 are close together, so as to allow operation of the feed ends of the inclined screen decks in a common pond formed from an applied feed 28, in the manner described in WO2015/166282. In other examples screen decks may be spaced further apart to allow conventional multi deck shale shaker operations, including operating with flow directing trays between the screen decks.

(16) In FIG. 2e, similar to FIG. 2d, cover plate 36 mounts two flanges 38, 46 projecting forwards and downwards to provide mountings 40 for bolting on a respective upper screen deck frame 42, 48. The three screen deck frames 16, 42 and 48 are staggered by the use of the flanges 38, 46 so that the feed receiving end of each screen deck frame is spaced further away from the fluid retaining wall 3 than the screen deck frame below. Where same length screen deck frames are employed this results in a corresponding stagger at the solids discharge end 4 of the basket 1, like that visible in the basket shown in FIG. 1.

(17) In this example, the three screen deck frames 16, 42 and 48 are close together, in the manner described in WO2015/166282 so as to allow operation of the feed ends of the inclined screen decks in a common pond formed from an applied feed 28.

(18) The flanges 38 (in FIG. 2d) and 46 (in FIG. 2e) also serve to deflect an applied solids and liquid feed 28 forwards onto the uppermost screening surface.

(19) In the arrangement depicted in FIGS. 2d and 2e there is a cavity or headspace 50, 52 formed above the screen deck below by the use of flanges 38 and 46. The cavity extends to higher than the extreme end of the screening surface of the screen deck above. This has been shown to provide benefits in terms of avoiding blockages and reduced screen wear in operation of a machine with closely spaced screen decks.

(20) FIGS. 3a and 3b each show in partial schematic cross section and elevation the rear feed end 2 of a basket generally of the form shown in FIG. 1 but modified to be a basket system of the first aspect of the disclosure.

(21) In FIG. 3a, a first (lower in this example) screen deck frame 16, which mounts a screening surface in use, is fixed to a flange 18 of the fluid retaining wall 3. Also visible in this view is a mount for a second screen deck that includes covered bolt holes 48 along the side of the basket and covered or plugged fixing hole(s) 50 for mounting a flange as discussed below with respect to FIG. 3b. A feed conduit 52 directs a feed suggested by arrows 28 down through a replaceable feed distribution end 54 in a direction towards the fluid retaining wall 3 and flange 18. The extreme end 56 of feed distribution end 54 is close to flange 18. Flow 28 turns from the direction of wall 3 back across flange 18 for processing on the screen deck.

(22) In FIG. 3b, in addition to first (lower) screen deck frame 16 an additional screen deck frame 42 is fitted to convert the basket into a two deck arrangement. Frame 42 is mounted by means of holes 48 (FIG. 3a) and fixing to flange 38. A feed conduit 52 directs a feed suggested by arrows 28 down through a replaceable feed distribution end 54A, shorter than that employed in FIG. 3a, in a direction towards the fluid retaining wall and flange 38. The extreme end 56 of feed distribution end 54A is close to flange 28. Flow 28 turns from the direction of wall 3 back across flange 38 for processing on the screen deck.