Trapezoid settler apparatus and method for solvent extraction

1. A trapezoid settler having a longitudinal axis that extends between an upstream region and a downstream region and a transverse plane generally normal to the longitudinal axis, comprising:

a base the lies in a generally horizontal plane, wherein the base has a downstream end and an upstream end;

a weir assembly located at the downstream end of the base at a first axial position;

a first side wall, having a first inner face, that extends between the upstream end of the base and the weir assembly, wherein the first side wall is oriented at a first angle to the longitudinal axis and wherein said first angle is greater than zero degrees;

a second side wall opposing the first side wall, having a second inner face, that extends between the upstream end of the base and weir assembly, wherein the second side wall is oriented at a second angle to the longitudinal axis and wherein said second angle is greater than zero degrees; and

a first coalescence fence connected to the first side wall and the second side wall, wherein the first coalescence fence extends between the inner face of the first and second side walls at a second axial position along the longitudinal axis, wherein the first coalescence fence comprises:

a first screen;

a second screen oriented generally parallel to the first screen; and

a media disposed between the first screen and the second screen;

wherein the first and second side walls each respectively comprise first sections that extend at angles inwardly, toward one another, as they extend from the upstream end of the base toward the first coalescence fence, respectively.

2. The trapezoid settler of claim 1 , further comprising a second coalescence fence having two ends connected to the first side wall and the second side wall, wherein the second coalescence fence extends between each inner face of the first and second side walls at a third axial position along the longitudinal axis.

3. The trapezoid settler of claim 2 , further comprising a first crud removal system positioned at a fourth axial location along the longitudinal axis upstream of the second coalescence fence.

4. The trapezoid settler of claim 3 , further comprising a second crud removal system positioned at a sixth axial location along the longitudinal axis upstream of the first coalescence fence, and a third crud removal system positioned at a seventh axial location along the longitudinal axis upstream of the weir assembly.

5. The trapezoid settler of claim 2 , wherein the second coalescence fence comprises:

a variable permeability screen;

a first jacking screw located on one of the two ends of the second coalescence fence; and

a second jacking screw located on the other end of the second coalescence fence wherein the jacking screws translate the second coalescence fence along the vertical axis.

6. The trapezoid settler of claim 2 , wherein the second coalescence fence and weir assembly are angled to the axial axis.

7. The trapezoid settler of claim 6 , wherein the second coalescence fence and weir assembly are positioned at an angle to the transverse plane equal to approximately zero degrees to approximately ten degrees.

8. The trapezoid settler of claim 2 , further comprising a first recycle launder located at a fourth axial location along the longitudinal axis downstream of the second coalescence fence.

9. The trapezoid settler of claim 8 , further comprising a second recycle launder located at a fifth axial location along the longitudinal axis upstream of the weir assembly.

10. The trapezoid settler of claim 1 , wherein the first coalescence fence is generally parabolic in shape.

11. The trapezoid settler of claim 1 , wherein the first coalescence fence is generally trapezoid in shape.

12. The trapezoid settler of claim 1 , wherein the inlet screen, the outlet screen, and the media are metal.

13. The trapezoid settler of claim 1 , wherein the inlet screen, the outlet screen, and the media are plastic.

14. The trapezoid settler of claim 1 , wherein the base is sloped at an angle to the horizontal plane.

15. The trapezoid settler of claim 1 , wherein the angle of the first side wall and second side wall to the longitudinal axis is equal to approximately zero degrees to approximately eighty-two degrees.

16. A trapezoid settler having a longitudinal axis that extends between an upstream region and a downstream region and a transverse plane generally normal to the longitudinal axis, comprising:

a base that lies in a generally horizontal plane, wherein the base has a downstream end and an upstream end;

a weir assembly located at the downstream end of the base at a first axial position;

a first side wall, having a first inner face, that extends between the upstream end of the base and the weir assembly, wherein the first side wall is oriented at a first angle to the longitudinal axis and wherein said first angle is greater than zero degrees;

a second side wall opposing the first side wall, having a second inner face, that extends between the upstream end of the base and the weir assembly, wherein the second side wall is oriented at a second angle to the longitudinal axis and wherein said second angle is greater than zero degrees; and

a first coalescence fence connected to the first side wall and the second side wall, wherein the first coalescence fence extends between each inner face of the first and second side walls at a second axial position along the longitudinal axis, wherein the first coalescence fence comprises:

a first screen;

a second screen oriented generally parallel to the first screen; and

a media disposed between the first screen and the second screen, wherein the angle of the first side wall and second side wall to the longitudinal axis is equal to approximately eleven to approximately seventeen degrees.

17. A trapezoid settler having a longitudinal axis that extends between an upstream region and a downstream region and a transverse plane generally normal to the longitudinal axis, comprising:

a base the lies in a generally horizontal plane, wherein the base has a downstream end and an upstream end;

a weir assembly located at the downstream end of the base at a first axial position;

a first side wall, having a first inner face, that extends between the upstream end of the base and the weir assembly, wherein the first side wall is oriented at a first angle to the longitudinal axis and wherein said first angle is greater than zero degrees;

a second side wall opposing the first side wall, having a second inner face, that extends between the upstream end of the base and weir assembly, wherein the second side wall is oriented at a second angle to the longitudinal axis and wherein said second angle is greater than zero degrees; and

an influent channel distributor connected to the first side wall and the second side wall, wherein the influent channel distributor extends between each inner face of the first and second side wall at a first axial position along the longitudinal axis, wherein the influent channel distributor comprises:

a first screen;

a second screen oriented generally parallel to the first screen;

a third screen oriented generally parallel to the second side wall and opposed to the second screen and

a barrier located upstream of the first screen,

wherein the first and second side walls each respectively comprise first sections that extend at angles inwardly, toward one another, as they extend from the upstream end of the base toward the first influent channel distributor, respectively.

18. A trapezoid settler having a longitudinal axis that extends between an upstream region and a downstream region and a transverse plane generally normal to the longitudinal axis, comprising:

a base the lies in a generally horizontal plane, wherein the base has a downstream end and an upstream end wall;

a weir assembly located at the downstream end of the base at a first axial position;

a first side wall, having a first inner face, that extends between the upstream end wall of the base and the weir assembly, wherein the first side wall is oriented at a first angle to the longitudinal axis and wherein said first angle is greater than zero degrees;

a second side wall opposing the first side wall, having a second inner face, that extends between the upstream end of the base and weir assembly, wherein the second side wall is oriented at a second angle to the longitudinal axis and wherein said second angle is greater than zero degrees; and

a first coalescence fence connected to the first side wall and the second side wall, wherein the first coalescence fence extends between the inner face of the first and second side walls at a second axial position along the longitudinal axis, wherein the first coalescence fence comprises:

a first screen;

a second screen oriented generally parallel to the first screen; and

a media disposed between the first screen and the second screen;

wherein the first and second side walls each respectively comprise first sections that extend at angles inwardly, toward one another, as they extend from the upstream end wall of the base toward the first coalescence fence, respectively.

19. A trapezoid settler having a longitudinal axis that extends between an upstream region and a downstream region and a transverse plane generally normal to the longitudinal axis, comprising:

a base the lies in a generally horizontal plane, wherein the base has a downstream end wall and an upstream end;

a weir assembly located at the downstream end wall of the base at a first axial position;

a first side wall, having a first inner face, that extends between the upstream end of the base and the weir assembly, wherein the first side wall is oriented at a first angle to the longitudinal axis and wherein said first angle is greater than zero degrees;

a second side wall opposing the first side wall, having a second inner face, that extends between the upstream end of the base and weir assembly, wherein the second side wall is oriented at a second angle to the longitudinal axis and wherein said second angle is greater than zero degrees; and

an influent channel distributor connected to the first side wall and the second side wall, wherein the influent channel distributor extends between each inner face of the first and second side wall at a first axial position along the longitudinal axis, wherein the influent channel distributor comprises:

a first screen;

a second screen oriented generally parallel to the first screen;

a third screen oriented generally parallel to the second side wall and opposed to the second screen and

a barrier located upstream of the first screen,

wherein the first and second side walls each respectively comprise first sections that extend at angles inwardly, toward one another, as they extend from the downstream end wall of the base toward the first influent channel distributor, respectively.