Vibratory separator

1. An apparatus for separating solids from a drilling fluid comprising:

a basket having two opposed spaced-apart side walls having first ends and second ends, the first ends spaced apart by an end wall connected to each of the side walls, the basket further including a bottom wall through which a fluid outlet passage is defined;

a plurality of screening surfaces having a front edge and a back edge and positioned within the basket between the side walls with each screening surface spaced apart vertically from adjacent screening surfaces and the back edge spaced apart from the end wall of the basket;

wherein the back edge of each screening surface is lower than the front edge of the corresponding screening surface;

a plurality of weirs, each weir retained along the back edge of a corresponding screening surface and spaced apart from the end wall to define a fluid passage between each weir and the end wall;

wherein each weir has a top edge extending to a weir height above the back edge of the corresponding screening surface and the top edge is lower than the front edge of the corresponding screening surface;

at least one flow director catching unseparated drilling fluid overflowing the weir of an upper adjacent screening surface into the fluid passage and directing the unseparated drilling fluid onto a lower screen; and

wherein fluid in the fluid passage between the lowermost screen and the end wall is directed to a spillover fluid outlet.

2. The apparatus of claim 1 , wherein each the of plurality of screening surfaces includes a pair of spaced-apart side edges extending between the front edge and the back edge;

wherein the side edges are spaced apart from the side walls of the basket; and

wherein the apparatus further comprises:

a pair of opposed side dams retained along at least a portion of the side edges of each screening surface and spaced apart from the side walls to further define the fluid passage between each weir and the side wall; and

wherein the at least one flow director further catches flow of unseparated drilling fluid in the fluid passage and directs the flow onto the lower adjacent screening surface.

3. The apparatus of claim 1 , further comprising:

a flow back pan beneath an upper screening surface that directs separated fluid to the flow director.

4. The apparatus of claim 1 wherein the uppermost weir is adjustable in height relative to the uppermost screening surface.

5. The apparatus of claim 1 wherein each weir height is adjustable.

6. The apparatus of claim 1 wherein the flow director further comprises: a conduit directing fluid onto the immediately lower adjacent screening surface.

7. The apparatus of claim 1 wherein the flow director further comprises:

a tray extending from the end wall to catch fluid flow from the fluid passage and direct the flow onto the lower adjacent screening surface.

8. The apparatus of claim 7 , wherein each the of plurality of screening surfaces includes a pair of spaced-apart side edges extending between the front edge and the back edge;

wherein the side edges are spaced apart from the side walls of the basket; and

wherein the apparatus further comprises:

a pair of opposed side dams retained along at least a portion of the side edges of each screening surface and spaced apart from the side walls to further define the fluid passage between each weir and the side wall; and

wherein the tray catches flow of unseparated drilling fluid in the fluid passage and directs the flow onto the lower adjacent screening surface.

9. An apparatus for separating solids from drilling fluid comprising:

a basket having two opposed spaced-apart side walls having first ends and second ends, the first ends spaced apart by an end wall connected to each of the side walls;

a plurality of screening surfaces having a front edge, a back edge, and a pair of spaced-apart side edges, the side edges extending between the front edge and the back edge;

wherein the screening surfaces are positioned within the basket between the side walls with each screening surface spaced apart vertically from adjacent screening surfaces and the back edge spaced apart from the end wall of the basket;

wherein the back edge of each screening surface is lower than the front edge of the corresponding screening surface;

wherein the side edges of the uppermost screening surface are spaced-apart from the side walls of the basket;

a plurality of weirs, wherein each weir is retained along the back edge of a corresponding screening surface and is spaced apart from the end wall to define a fluid passage between each weir and the end wall;

wherein each weir has a top edge extending to a weir height above the back edge of the corresponding screening surface and the top edge is lower than the front edge of the corresponding screening surface;

wherein each weir height is adjustable;

at least one flow director catching unseparated drilling fluid overflowing the weir of an upper adjacent screening surface into the fluid passage and directing the unseparated drilling fluid onto a lower screen; and

a pair of opposed side dams retained along at least a portion of the side edges of the uppermost screening surface and spaced apart from the side walls to further define the fluid passage.

10. The apparatus of claim 9 , further comprising:

a flow back pan beneath an upper screening surface that directs separated fluid to the flow director.

11. The apparatus of claim 9 wherein the flow director further comprises:

a conduit directing fluid onto the immediately lower adjacent screening surface.

12. The apparatus of claim 9 wherein the flow director further comprises:

a tray extending from the end wall into the fluid passage and over the immediately lower adjacent screening surface.

13. The apparatus of claim 9 wherein the uppermost screening surface comprises a scalping screen.

14. An apparatus for separating solids from a fluid comprising:

a basket having two opposed spaced-apart side walls having first ends and second ends, the first ends spaced apart by an end wall connected to each of the side walls;

a plurality of screening surfaces positioned within the basket between the side walls with each screening surface spaced apart vertically from adjacent screening surfaces, wherein each screening surface includes a front edge, a back edge spaced-apart from and lower than the front edge, and a pair of spaced-apart side edges, the side edges extending between the front edge and the back edge and the back edge spaced-apart from the end wall;

a weir retained along the back edge of each screening surface and spaced apart from the end wall to define a fluid passage between each weir and the end wall;

wherein each weir has a top edge extending to a weir height above the back edge of a corresponding screening surface and the top edge is lower than the front edge of the corresponding screening surface; and

at least one flow director catching unseparated fluid overflowing the weir of an upper adjacent screening surface into the fluid passage and directing the unseparated fluid onto a lower screen.

15. The apparatus of claim 14 wherein each weir height is adjustable.

16. The apparatus of claim 15 , further comprising:

a flow back pan beneath an upper screening surface that directs separated fluid to the flow director.

17. The apparatus of claim 16 wherein the flow director further comprises:

a conduit directing fluid onto the immediately lower adjacent screening surface.

18. The apparatus of claim 16 wherein the flow director further comprises:

a tray extending from the end wall into the fluid passage and over the immediately lower adjacent screening surface.

19. The apparatus of claim 14 wherein the uppermost screen further comprises a scalping screen.

20. The apparatus of claim 19 wherein each screening surface lower in the basket includes a screen having a mesh size for separating finer solids than the screening surface higher in the basket.