Not applicable.
The present invention relates to apparatus for screening a mixture of fluids and solids. More particularly, the present invention relates to a vibratory separator having an vibration amplifier system for the purpose of increasing G forces on the screen assembly.
Vibrating screens have been employed for many years to separate particles in a wide array of industrial applications. One common application of vibrating screens is in drilling operations to separate particles suspended in drilling fluids. The screens are mounted generally horizontally on a vibrating mechanism or shaker that imparts a desired motion to the screen. Material from which particles are to be separated is poured onto a back end of the vibrating screen usually from a pan mounted above the screen. The material generally flows toward the front end of the screen. Large particles are unable to move through the screen remain on top of the screen and move toward the front of the screen where they are collected. The smaller particles and fluid flows through the screen and collects in a tank, receptacle or pan beneath the screen.
Typically, a vibrating screen is resiliently suspended or mounted upon a support and is caused to vibrate by a vibrating mechanism, e.g. an unbalanced weight on a rotating shaft connected to a basket or frame. The screen is vibrated by vibratory equipment to create a flow of trapped solids on top surfaces of the screen for removal and disposal of solids. The fineness or coarseness of the mesh of a screen may vary depending upon mud flow rate and the size of the solids to be removed.
The need for solids control in drilling mud used in hydrocarbon well drilling is well-known in the prior art. Drilling mud, typically a mixture of clay and water and various additives, is pumped down through a hollow drill string (pipe, drill collar, bit, etc.), into a well being drilled and exits through holes in a drill bit. The mud picks up cuttings (rock) and other solids from the well and carries them upwardly away from the bit and out of the well in a space between the well walls and the drill string. At the top of the well, the solids-laden mud is discharged over a shale shaker, a device which typically has a screen or a series of screens arranged in tiered or flat disposition with respect to each other. The prior art discloses a wide variety of vibrating screens, devices which use screens, shale shakers, and screens for shale shakers. The screens catch and remove solids from the mud as the mud passes through them. If drilled solids and/or debris are not removed from the mud used during the drilling operation, recirculation of the drilled solids can create weight, viscosity, and gel problems in the mud, as well as increasing wear on pumps and other mechanical equipment used for drilling.
A conventional type of vibratory separator comprises a screen assembly driven by two electric or hydraulic motors with unbalanced weights on the end of the motor of the drive shaft of the motors. The drive shafts rotate in opposite directions. The location of the motors facilitates the transference of G forces generated by the motors to the screen assembly. These G-forces generate a vibratory motion pattern and constant acceleration. When the slurries or solids are fed to the screen assembly, the G forces decrease, thereby limiting the amount of energy required to produce an efficient separation. Accordingly, by increasing the G-forces, heavier loads may be processed, fluid capacity may be increased, and separation efficiency may also be increased.
In mineral processing applications, vibratory separators or high-frequency vibrating screens separate solids in different sizes or solids from a liquid phase depending on the size and shape of the screen openings. Typically, the high-frequency vibrating screen is an angled basket operating between 900 and 1800 rpm with G-forces in the range of four to seven G's. The vibrating screen has an orbital or linear motion at a fixed vibration angle.
In other applications, such as oil well drilling, vibratory separators or shale shakers remove certain large particles while allowing certain smaller particles to remain in the fluid. The large particles include drilled solids. The smaller particles may include drilling fluid additives. The screen assembly on the shale shakers determines the size of the solids to be removed based on the size and shape of the screen openings. The efficiency of the separation is also affected by parameters such as fluid flow rates, particle size and drilling fluid properties, including viscosity, density and solids content. Typically, the shale shaker is a horizontal basket operating at between 1200 to 18 rpm with G-forces in the range of five to seven G's, with a linear or balanced elliptical motion and a fixed vibration angle.
Typically, in the mineral processing industry, the operating parameters that affect screening or separation efficiency are constant, thus the design parameters of the vibratory separator are fixed. However, when the operating parameters change, such as in oil well drilling, for example, they could adversely affect overall system performance or separation efficiency, leading to solids and/or liquid bypassing and machine overload. One solution to this problem is the manual adjusting of the screen assembly angle, known as “deck angle”. A drawback of this solution, however, is that at deck angles greater than 3°, solids grinding, or degradation, can be a problem. Another known solution is to simply install a coarser mesh on the discharge end. Both solutions are sometimes unsatisfactory, however, since they are both subjective and involve human error. As such, there is a need that exist for a method and apparatus for screening with higher G-forces to ensure an efficient operation.
In the past, various patents have issued relating to such vibratory screening systems. For example, an early patent is that of U.S. Pat. No. 3,899,414, issued on Aug. 12, 1975 to L. T. Hansen. This patent describes a vibratory screen separator having an arcuate plate which receives sediment from a plurality of hydrocyclones and distributes the sediment to the separator screen. The arcuate plate collects the sediment from a plurality of discharge positions and presents it to a centrally positioned outlet where it can fall onto a separator screen. The arcuate plate is itself positioned on the vibratory screen separator and is caused to vibrate therewith. The arcuate plate in combination with a grate over the centrally positioned outlet also provides a cover for the separator to prevent large objects from damaging the screen.
U.S. Pat. No. 6,269,953, issued on Aug. 7, 2001 to Seyffert et al., discloses a vibratory separator screen assembly which has at least two ridge-valley series of screening material with a plurality of alternating ridges and valleys of screening material. There is at least one flat area of screening material adjacent to the ridge-valley series.
U.S. Pat. No. 6,401,934, issued on Jun. 11, 2002 to Largent et al., teaches a ramped screen and vibratory separator system. The screen assembly has a base, at least one layer of screening material on the base, and at least one ramp formed in the layer of screening material.
U.S. Pat. No. 6,439,391, issued on Aug. 27, 2002 to K. W. Seyffert, shows a vibratory separator apparatus for separating components of a fluid stream fed to the vibratory separator apparatus. The vibratory separator apparatus has a separator apparatus for separating components of the fluid material stream and a heating apparatus for heating the fluid material stream.
U.S. Pat. No. 6,715,611, issued on Apr. 6, 2004 to Crabbe et al., provides a vibratory separator for separating components of material introduced thereto. The vibratory separator is a shale shaker. The vibratory separator includes a basket for holding the screening apparatus. The basket has two sides spaced-apart at a first end at which the material is introduced into the basket and a second end spaced away from the first end. Components separated from the material exit the basket from the second end. A vibrating apparatus is connected to the basket for vibrating the basket. The screening apparatus is mounted in the basket. The screening apparatus has at least a first portion and a second portion. The first portion is at the first end of the screen and is lower in the basket than the second portion. A receptacle is below the screening apparatus for receiving material components flowing through the screening apparatus.
U.S. Pat. No. 6,845,868, issued on Jan. 25, 2005 to Krush et al., describes a vibratory separator which includes a multi-frequency vibratory adapter system that converts the single frequency vibration into multiple-frequency vibrations of the screen or sieve surface. The peak acceleration caused by the multi-frequencies at least an order of magnitude greater than the main frequency acceleration. A disadvantage of the system is the generation of frequencies that are out-of-phase. This is detrimental to the conveyance of solids.
U.S. Pat. No. 7,000,776, issued on Feb. 21, 2006 to Winkler et al., teaches a screen assembly for vibratory separators. The screen assembly includes a first screen portion having a first end and a second end spaced away from the first end. A second screen portion is adjacent to the second end of the first screen portion. The second screen portion projects downwardly from the second end of the first screen portion.
U.S. Pat. No. 7,175,027, issued on Feb. 13, 2007 to Strong et al., discloses a screen assembly and a vibratory separator. The vibratory separator serves to separate components of material introduced therein. The vibratory separator includes a basket, a collection receptacle beneath the basket and a deck on the basket for mounting the screen assembly thereon. The deck has a plurality of deck pins projecting upwardly therefrom. A screen assembly is positioned on the deck. The screen assembly includes screening material. The screening material has a plurality of openings therethrough suitable for the flow of fluid therethrough. The screening material has a plurality of spaced-apart screen holes therethrough. A holding apparatus is provided for holding the screen assembly on the deck with a part of a deck pin in each screen hole.
U.S. Pat. No. 7,216,767, issued on May 15, 2007 to Schulte et al., teaches a screen basket and shale shaker. The screen mounting basket for a vibratory separator serves to separate components of material introduced into the basket. The vibratory separator includes a collection receptacle beneath the basket. The basket includes two opposed spaced-apart side walls having first ends and second ends. The first ends are spaced-apart by spaced-apart end walls connected to each of the side walls. A basket bottom is located between the two spaced-apart side walls. At least one screen assembly is positioned vertically in the basket for intercepting material introduced into the basket and for screening this material. The screen assembly extends from one side wall of the basket to the other.
U.S. Pat. No. 7,278,540, issued on Oct. 9, 2007 to Stone et al., discloses a vibratory separator having a base, a basket movably mounted on the base for supporting a screen apparatus for treating material introduced into the vibratory separator. The basket is located on a base and is pivotable with respect thereto. The vibratory apparatus is connected to the basket for vibrating the basket. The screen apparatus is supported by the basket. An angle adjustment apparatus is connected to the basket for adjusting an angle of the basket. A sensor senses a parameter indicative of basket angle and provides a signal corresponding to this basket angle. A control apparatus receive signals from the sensor apparatus and controls the basket angle based upon the signals. The angle adjustment apparatus includes a rocker arm assembly with a first pivotable end.
U.S. Pat. No. 7,331,469, issued on Feb. 19, 2008 to Padalino et al., discloses a vibratory separator with an automatically adjustable beach. The vibratory separator has a basket for supporting a screen apparatus for treating material. The basket is pivotally mounted on a base. The vibratory apparatus is connected to the basket for vibrating the basket. A beach is formed on the screen apparatus. A measurement device is connected to the basket and positioned above the screen for measuring a distance from the measurement apparatus to a top surface of the pool. A control apparatus controls and communicates with the measurement apparatus for receiving signals therefrom which is indicative of a pool depth. An adjustment apparatus is used for adjusting the angle of the basket and adjusting the extent of the beach.
U.S. Pat. No. 7,571,817, issued on Aug. 11, 2009 to Scott et al., provides an automatic separator or shaker with an electromagnetic vibrator apparatus. This vibratory separator has a base, a basket movably mounted on the base, a screen on the basket, in which a least a portion of the screen is not inclined downhill. An electromagnetic vibratory apparatus is connected to the basket for vibrating the basket in the screen apparatus. A driving apparatus drives the electromagnetic vibratory apparatus. The control apparatus controls the driving apparatus and the electromagnetic vibratory apparatus.
U.S. Pat. No. 7,954,644, issued on Jun. 7, 2001 to Lease et al., teaches a separator system having a first trough having an inlet end, a downstream outlet end and a trough floor. A first screen section is supported in the trough and is spaced from the trough floor. The first screen section has a first end at the second downstream end. A material-retaining surface is disposed at the downstream end of the first screen section. The material-retaining surface is disposed at an angle relative to the first screen section in order to limit the movement of material across the first screen section. A vibratory generator is coupled to the trough.
U.S. Pat. No. 8,118,172, issued on Feb. 21, 2012 to G. A. Burnett, shows a shale shaker with cartridge screen assembly. The screening apparatus includes a vibratable box connected via vibration isolators within a container. The box includes a screening apparatus thereon. The vibratory separator has replaceable screening cartridges within a container.
U.S. Pat. No. 9,023,275, issued on May 5, 2015 to G. L. McClung, provides shale shakers and separators with real-time monitoring of operation. A killing apparatus serves to kill living things in a fluid flowing from the separator or shaker. A heating apparatus is provided for heating the material fed into or flowing from the separator or shaker.
U.S. Patent Application Publication No. 2007/0108105, published on May 17, 2007 to G. A. Burnett, discloses an upflow shaker and separator. In particular, the separator system includes a container, a screen apparatus with a box, and at least one screen on the box. The screen has a plurality of holes therethrough through which the liquid is passable and through which the solids are not passable. A vibratory apparatus vibrates the box and the screen. The material to be treated is flowable up to the screen and liquid in the material as flowable to and through the screen. A primary conveyor is located beneath the screen for removing solids from liquid.
U.S. Patent Application Publication No. 2007/0108106, published on May 17, 2007 to G. A. Burnett, provides a vibratory separator system including a basket for containing material to be treated by vibratory action. The screen apparatus in the basket screens solids from the material. The screening apparatus includes a screen support with at least one screen through which liquid in the material is passable and through which solids in the material are not passable. A first vibratory apparatus is secured to the screen support for vibrating the screen support and thereby vibrating the screen. A second vibratory apparatus is connected to the screen for vibrating the screen.
It is an object of the present invention to provide a vibratory separator system that applies increased G-forces during the screening process.
It is another object of the present invention to provide a vibratory separator system that is effective across a variety of sizes of particles.
It is another object of the present invention to provide a vibratory separator system that is able to process heavier loads.
It is another object of the present invention to provide a vibratory separator system that can increase fluid capacity.
It is another object of the present invention to provide a vibratory separator system that increases separation efficiencies.
It is a further object of the present invention to provide a vibratory separator system that avoids human error and subjective judgment.
It is another object of the present invention to provide a vibratory separator system that is adjustable to control G-forces on the screen assembly.
It is still further object of the present invention to provide a vibratory separator system that is capable of generating G-forces in the range of between ten and thirty G's.
It is another object of the present invention provide a vibratory separator system that is less prone to clogging or binding.
It is still a further object of the present invention to provide a vibratory separator system that has increased strength so as to be able to withstand G-forces.
It is still further object of the present invention to provide a vibratory separator system that ensures optimum performance.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.
The present invention is vibrator separator system that comprises a vibratory separator positioned in a vibrating basket, a screen assembly positioned in the vibratory separator, and a vibration amplifier coupled to the vibratory separator. The vibratory basket has sides arranged in spaced relation to each other. The vibratory separator has at least one motor affixed thereto. The vibratory basket has an inlet end and a discharge end. The screen assembly extends between the inlet end and the discharge end of the vibratory basket. The motor is cooperative with a screen assembly so as to impart a vibration frequency to the screen assembly. The vibration amplifier is positioned beneath the screen assembly. The vibration amplifier is cooperative with the screen assembly so as to exert a force against a portion of an underside of the screen assembly.
In the present invention, the motor is an electric motor or a hydraulic motor. In particular, the motor can include a pair of motors that are affixed to the vibratory basket so as to exert vibrations to the screen assembly positioned in the vibratory separator.
At least one pressure wedge clamps the screen assembly to the vibratory separator. In particular, the screen assembly comprises a plurality of screen assemblies arranged in end-to-end relation within the vibratory basket. The pressure wedge comprises a plurality of pressure wedges respectively clamping the plurality of screen assemblies to the vibratory separator.
The screen assembly comprises a pre-tensioned frame clamped to the vibratory separator and a screen affixed within the pre-tensioned frame. The pre-tensioned frame has a pair of side bars in spaced parallel relation to each other and a pair of end bars extending between the pair of side bars and positioned at opposite ends of the pre-tensioned frame. The pre-tensioned frame has no ribs extending between the pair of side bars in an area between the pair of end bars.
The vibratory separator has a screen deck positioned in the vibratory basket. The screen deck receives the screen assembly thereon.
The vibration amplifier includes a housing coupled to the vibratory separator, a flexible mass mounted inside the housing, and a beater bar coupled to the flexible mass. The vibration amplifier is in contact with a central portion of the screen assembly. The beater bar contacts or bears against the screen assembly so as to keep the screen assembly under tension. The vibration amplifier extends over no more than 40% of a total area of the screen assembly. The vibration amplifier is in phase with the vibration frequency of the vibratory separator. The screen deck has a support. The rigid housing is affixed with fasteners to the support. The housing has a mounting base that is secured to mounts bolted to a frame of the vibratory basket. The flexible mass has a thickness of between one and four inches. The flexible mass is formed of a material selected from the group consisting of an elastomer, a plastic material and a seal material.
A rigid center piece can be positioned within a hollow interior of the flexible mass. The beater bar is mounted to a top of the rigid plate connected to the flexible mass. The beater bar is retained by a fastener and spaced from the rigid plate. The beater bar has at least a pair of flexible strips retained by rivets or bolts and glued to the beater bar. An additional weight can be removably affixed to the rigid center piece.
The beater bar can comprise a pair of rigid bars extending in parallel relation to each other. The pair of flexible strips are respectively affixed to a top of the pair of rigid bars. The screen assembly has a pre-tensioned frame of the screen assembly is adapted to resist a striking force of the beater bars at G-forces in a range of between ten and thirty G's.
The present invention is also an improved method and apparatus for screening. The present invention comprises a vibratory separator driven by two drive motors having respective out-of-balance weights arranged to produce acceleration. There are one or more vibration amplifiers located beneath the screen assembly so as to enhance the separation efficiency by providing higher G-forces on the screen assembly.
The vibration amplifier includes a flexible mass mounted inside a rigid frame. The rigid frame is mounted on a screen basket which transmits motion to the flexible mass. The flexible mass is coupled to a beater bar which strikes the screen assembly with a high G-force. The flexible mass of each amplifier has a relatively high amplitude in the direction perpendicular to the screen assembly.
This foregoing Section is intended to describe, with particularity, the preferred embodiments of the present invention. It is understood that modifications to these preferred embodiments can be made within the scope of the present claims. As such, this Section should not to be construed, in any way, as limiting of the broad scope of the present invention. The present invention should only be limited by the following claims and their legal equivalents.
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In particular,
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The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.
Number | Name | Date | Kind |
---|---|---|---|
3899414 | Hansen | Aug 1975 | A |
5232099 | Maynard | Aug 1993 | A |
6269953 | Seyffert | Aug 2001 | B1 |
6401934 | Largent | Jun 2002 | B1 |
6439391 | Seyffert | Aug 2002 | B1 |
6715611 | Crabbe | Apr 2004 | B2 |
6845868 | Krush | Jan 2005 | B1 |
7000776 | Winkler | Feb 2006 | B2 |
7175027 | Strong | Feb 2007 | B2 |
7216767 | Schulte | May 2007 | B2 |
7278540 | Stone | Oct 2007 | B2 |
7331469 | Padalino | Feb 2008 | B2 |
7571817 | Scott | Aug 2009 | B2 |
7954644 | Lease | Jun 2011 | B2 |
8118172 | Burnett | Feb 2012 | B2 |
9023275 | McClung | May 2015 | B2 |
20070108105 | Burnett | May 2007 | A1 |
20070108106 | Burnett | May 2007 | A1 |
20080078703 | Robertson | Apr 2008 | A1 |
20090230029 | Bailey | Sep 2009 | A1 |
20140217002 | Holton | Aug 2014 | A1 |
20170058621 | Bailey | Mar 2017 | A1 |
20180214798 | Cady | Aug 2018 | A1 |