Screening Apparatus
AssigneeAxiom Process Ltd.
InventorMarshall Graham BAILEY
Life of this patent
Estimating the term…
Abstract
A shale shaker includes a basket having a front, solids discharge end and a rear, feed end spaced apart by opposed first and second sides. The basket includes a lower, first, screen deck and an upper, second, screen deck directly above the first screen deck. The screening surfaces of the screen decks are spaced apart, by a vertical spacing of from 20 mm to 250 mm. There is a cavity above the feed receiving end of the first screen deck, in direct fluid communication with the space between the screening surfaces of the first and second screen decks ( ) that only receives feed that has passed through the upper, second, screen deck. The cavity extends to higher than the extreme end of the screening surface of the second screen deck, at its feed receiving end.
Claims42
A shale shaker comprising:
- a basket having a front, solids discharge end and a rear, feed end spaced apart by opposed first and second sides;
- said basket including a stack of screen decks, each screen deck having a screening surface, with the screening surface of the screen decks spaced apart and superposed one above the other;
- wherein the stack of screen decks comprises at least a lower, first, screen deck and an upper, second, screen deck directly above the first screen deck, and wherein the screening surfaces of the first and second screen decks are spaced apart, by a vertical spacing of from 20 mm to 250 mm, at the extreme end of the feed receiving end of the second screen deck;
- wherein the screening surfaces of each of the first and second screen decks have a lower, feed receiving, end that is proximal to a fluid retaining wall at the rear end of the basket and a distal, higher, solids discharge end at the front of the basket;
- wherein the feed receiving end of the second screen deck is further from the back of the basket than the feed receiving end of the first screen deck;
- wherein there is a cavity above the feed receiving end of the first screen deck, in direct fluid communication with the space between the screening surfaces of the first and second screen decks, and only receiving feed that has passed through the upper, second, screen deck;
- wherein the cavity extends to higher than the extreme end of the screening surface of the second screen deck, at the feed receiving end;
- and
- wherein, in normal use, there is no outlet for solids and liquid from the cavity other than to the screening surfaces of the first and second screen decks and the space between them.
The shale shaker of any preceding claim wherein the cavity is of a vertical height of from 115% to 1000% of the vertical spacing between the screening surfaces of the first and second screen deck, measured at the extreme end of the screening surface of the second screen deck, at the feed receiving end.
The shale shaker of any preceding claim wherein the cavity is defined by the feed receiving end of the lower first screen deck, the fluid retaining wall and a roof.
The shale shaker of any preceding claim wherein the feed receiving end of the second screen deck is further from the back of the basket than the feed receiving end of the first screen deck by a horizontal displacement of from 25 mm to 500 mm.
The shale shaker of any preceding claim wherein the vertical spacing between the screening surfaces of the first and second screen decks is substantially constant along their length, from the rear of the basket towards the front of the basket.
The shale shaker of any preceding claim wherein the length of each of the first and second screen decks, from the front of the basket to the rear of the basket is substantially the same.
The shale shaker of any preceding claim further provided with a third screen deck, directly above the second screen deck;
- wherein the screening surfaces of the second and third screen decks are spaced apart, by a vertical spacing of from 20 mm to 250 mm, at the extreme end of the feed receiving end of the third screen deck;
- wherein the screening surface of the third 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 of the basket;
- wherein the feed receiving end of the third screen deck is further from the back of the basket than the feed receiving end of the second screen deck;
- and
- wherein there is a second cavity, above the feed receiving end of the second screen deck in direct fluid communication with the space between the screening surfaces of the second and third screen decks, and only receiving feed that has passed through the third screen deck;
- the second cavity extending to higher than the extreme end of the screening surface of the third screen deck, at the feed receiving end.
The shale shaker of any preceding claim wherein the feed receiving end of the lower, first, screen deck is connected to the fluid retaining wall and the feed receiving end of the upper second screen deck is connected to a downwards directed flange of the fluid retaining wall projecting towards the front, solids discharge end of the basket.
The shale shaker of any preceding claim wherein the basket is further provided with a solids collecting and distribution chute, for separate collection of solids discharged from at least the first and second screen decks.
A solids collecting and distribution chute for a shale shaker, the chute comprising:
- first and second elongate troughs in a side by side relationship, the troughs extending across the width of basket of a shale shaker, in use, and divided by a wall;
- wherein at least one solids discharge port of the first elongate trough is formed to direct solids in a direction transverse to its length and at least one solids discharge port of the second elongate trough is formed to direct solids in a direction transverse to its length.
Dependencies are inferred from the claim text.