Source: http://www.freepatentsonline.com/6935511.html
Timestamp: 2020-02-23 15:10:18
Document Index: 485169121

Matched Legal Cases: ['art 14', 'art 14', 'art 14', 'art 18', 'art 18', 'art 18', 'art 14', 'art 16', 'art 14', 'art 16', '§102', '§102', '§103', '§103', '§112']

Centrally supported screen assembly - Varco I/P, Inc.
United States Patent 6935511
Seyffert, Kenneth W. (Houston, TX, US)
10/429263
209/405, 209/408, 209/413, 210/386, 210/388
B01D33/03; B07B1/46; B07B1/48; B07B1/49; B07B; (IPC1-7): B07B1/48; B01D33/00
209/413, 209/409, 209/404, 209/398, 210/388, 209/405, 210/499, 210/384, 209/412, 210/386, 209/408, 209/399
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PCT/GB03/03444 Int'l Search Report, 5 pages; Nov. 28, 2003.
Dwight Rettig (General Counsel National Oilwell Varco 10,000 Richmond Avenue, Houston, TX, 77042, US)
This is a continuation-in-part of U.S. application Ser. No. 10/418,743 filed 21 Apr. 2003 entitled “Vibratory Separator And Screen Assembly” naming George Alexander Burnett as inventor which is co-owned with the present invention and which is fully incorporated herein for all purposes.
1. A vibratory separator comprising a basket with a first side spaced-apart from a second side, screen assembly apparatus mounted in the basket, the screen assembly apparatus having a central portion, a first screen side and a second screen side, vibrating apparatus connected to the basket, central support apparatus connected to the basket and positioned beneath and in contact with the central portion of the screen assembly apparatus, pressing apparatus on the first side and second side of the basket for pressing down on the first screen side and on the second screen side of the screen assembly apparatus so that the central portion of the screen assembly apparatus is higher than the first screen side and the second screen side, wherein said pressing apparatus comprises inflatable bladder apparatus, wherein said screen assembly apparatus has a length and said central support apparatus has a length substantially equal to said length of said screen assembly apparatus, wherein said screen assembly apparatus includes a channel member beneath said central portion thereof, said channel member for receiving part of said central support apparatus, and wherein said screen assembly apparatus includes screen support apparatus for supporting screening material thereon, at least part of said central support apparatus contacting said screen support apparatus.
2. A vibratory separator comprising a basket with a first side spaced-apart from a second side, screen assembly apparatus mounted in the basket, the screen assembly apparatus having a central portion, a first screen side and a second screen side, vibrating apparatus connected to the basket, central support apparatus connected to the basket and positioned beneath and in contact with the central portion of the screen assembly apparatus, pressing apparatus on the first side and second side of the basket for pressing down on the first screen side and on the second screen side of the screen assembly apparatus so that the central portion of the screen assembly apparatus is higher than the first screen side and the second screen side, and wherein said screen assembly apparatus includes a channel member beneath said central portion thereof, said channel member for receiving part of said central support apparatus.
3. The vibratory separator of claim 2 wherein said pressing apparatus comprises inflatable bladder apparatus.
15. A vibratory separator comprising a basket with a first side spaced-apart from a second side, screen assembly apparatus mounted in the basket, the screen assembly apparatus having a central portion, a first screen side and a second screen side, vibrating apparatus connected to the basket, central support apparatus connected to the basket and positioned beneath and in contact with the central portion of the screen assembly apparatus, and pressing apparatus on the first side and second side of the basket for pressing down on the first screen side and on the second screen side of the screen assembly apparatus so that the central portion of the screen assembly apparatus is higher than the first screen side and the second screen side, wherein the central support apparatus has a top part for contacting the central portion of the screen assembly apparatus, the top part made of shock-absorbing material, and wherein said top part has a hollow portion.
In the drilling of a borehole in the construction of an oil or gas well, a drill bit is arranged on the end of a drill string and is rotated to bore the borehole. A drilling fluid or “drilling mud” is pumped through the drill string to the drill bit to lubricate the drill bit. The drilling mud is also used to carry the cuttings produced by the drill bit and other solids to the surface through an annulus formed between the drill string and the borehole. The drilling mud often contains expensive synthetic oil-based lubricants and it is normal therefore to recover and re-use the used drilling mud, but this requires the solids to be removed from the drilling mud. This is achieved by processing the drilling fluid. The first part of the process is to separate the solids from the solids laden drilling mud. This is at least partly achieved with a vibratory separator, such as those shale shakers disclosed in U.S. Pat. No. 5,265,730, WO 96/33792 and WO 98/16328.
FIG. 3A is a rear end view of the shale shaker and screen assembly shown in FIG. 3. FIG. 3B is a rear end view of part of the central clamp shown in FIG. 3. FIG. 3C is a side view of the part of the central clamp shown in FIG. 3. FIG. 3D is a view in cross-section of the part of the central clamp taken along line 3D—3D of FIG. 3c. FIG. 3E is a top view of the part of the central clamp of FIG. 3B. FIG. 3F is a top plan view of the screen assembly shown in FIG. 3, with a portion of screening material cutaway. FIG. 3G is a perspective view of the rear end and underneath of the screen assembly shown in FIG. 3. FIG. 3H is a side view of the screen assembly shown in FIG. 3. FIG. 3I is a view in cross-section taken along line 3I—3I of FIG. 3F. FIG. 3J is a view in cross-section taken along line 3J—3J of FIG. 3F. FIG. 3K is a rear end view of the screen assembly shown in FIG. 3. FIG. 3L is a rear end view of the screen assembly shown in FIG. 3, arranged in the side clamping rails and the central clamp of the shale shaker of FIG. 3, the central clamp deactivated. FIG. 3M is a rear end view of the screen assembly shown in FIG. 3, arranged in the side clamping rails and the central clamp of the shale shaker of FIG. 3, the central clamp activated.
Referring to FIG. 1, a prior art shale shaker 1 is shown with a screen assembly 2 mounted therein. The screen assembly comprises a frame (not shown) and a layer of screening material tensioned over the frame. The screen assembly 2 is mounted in a basket 3, which has: an open bottom, for allowing fluid and small particles to pass into a receptacle (not shown) therebeneath; a feed end at which material to be screen is introduced (to the right of the drawing) and a mouth (to the left of the drawing) for allowing large particles to pass into a skip or ditch. The basket 3 is mounted on springs 4 (only two shown; two as shown are on the opposite side) which are supported on a structure 6. The basket 3 and the screen assembly 2 mounted therein is vibrated by a motor 5 interconnected with vibrating apparatus 8. The vibrating apparatus 8 may be of the type which comprises an unbalanced weight on the end of the motors drive shaft. Elevator apparatus 7 provides for raising and lowering of the basket end. Typically the basket will be in a “climb the hill” position so that a pool of liquid is maintained at one end within the basket.
The area 106 of the blank shown in FIG. 2H has a plurality of apertures including a plurality of triangular apertures and a plurality of circular apertures formed therein. One of the triangular apertures is identified by reference numeral 118 and one of the circular openings is identified by reference numeral 119. The triangular aperture 118 is formed by first punching, laser cutting, sawing, drilling, milling or casting the blank with an opening 120, in the shape shown in the template shown in FIG. 1I. The shape comprises three semi circular ends 121, 122 and 123 each arranged within and close to where a respective vertex 124, 125 and 126 of the triangular aperture 118 is to be formed, as shown in FIG. 1G; and a small triangular opening 127 concentric with the triangular aperture 118 to be formed and slots 128, 129 and 130 link the semi circular ends 121, 122 and 123 to form structural portions 131, 132 and 133. The structural portions 131, 132 and 133 are folded downwardly along fold line 134, over a form tool (not shown) having a similar profile to the fold line 134. The structural portions 131, 132 and 133 are folded by the form tool to an angle of approximately 65 to the surface of the panel 101 to form edges 131a, 132a, and 133a. The areas 135, 136 and 137 of panel 101 bounding the semi circular ends 121, 122 and 123 are also folded downwardly.
Referring back to FIGS. 1D and 1G, triangular apertures, such as triangular aperture 118, are arranged in ten full sets of rows in the panel 101 and one further row of a set. A first set 138 comprises a first row 139 having a rearwardly pointing triangular aperture 118 and a forwardly pointing triangular aperture 140 adjacent thereto, such that folded structural portion 132 and a folded structural portion 141 of the forwardly pointing triangular aperture 140 form a panel rib 142, approximately 2.3 mm wide. An apex 143 of the forwardly pointing triangular aperture 140 is rearwardly offset by approximately 2.3 mm from a base edge 131a of the rearwardly pointing triangular aperture 118. The first row 139 comprises twelve forwardly pointing triangular apertures interspaced by twelve rearwardly pointing triangular apertures. The first set 138 also comprises a second row 144, which is a mirror image of the first row 139 about line A—A. A structural portion 145 of forwardly pointing triangular aperture 140 of the first row 139 and a structural portion 146 of a rearwardly pointing triangular aperture 147 of the second row 144, form a panel rib 148. The underside of panel rib 148, the structural portion 145 and the structural portion 146 form a channel. The panel rib 148 is in line with panel ribs 149 to 159 in the first set 138, the undersides of which form a channel which extends the width of the panel 101. Circular opening 119 is drilled, punched, laser cut or otherwise formed in the panel 101 between vertices 125, 160, 161 and 162 of rearward pointing triangular aperture 118, forward pointing triangular aperture 163, forward pointing triangular aperture 140 and rearward pointing triangular aperture 147 respectively. A segment opening 164 arranged between rearward pointing triangular aperture 118, forward pointing triangular aperture 163 and circular hole 119 is punched, laser cut or otherwise formed in the panel 101, having a straight portion following line 110 of the blank, shown in FIG. 1H and a curved portion extending toward the rearward pointing triangular aperture 118, forward pointing triangular aperture 163 and circular opening 119.
Rigid steel tubes 309 and 310 and further rigid steel tubes (not shown) spaced along the bottom of the basket 301 link the two sides 302 and 303. A central clamp, generally identified by reference numeral 311, is fixed to the center of the rigid steel tube 309 by solid steel plates 312, 313. The central clamp 311 is also fixed to the other rigid steel tubes 310 and (not shown) using similar steel plates (not shown). The central clamp 311 comprises a housing 314, which extends substantially the entire length of the basket 301. The housing 314 is arranged to be parallel to the C-shape rails 305 and 306. The housing 314 may extend from the mouth of the basket and slightly further than the C-shape side rails 305 and 306. The outer housing 314 has two sidewalls 315 and 316 welded to a bottom plate 316a. Each of the two sidewalls 315 and 316 has an upper portion 317 and 318 folded at right angles to form a shoulders and a slot 319 therebetween. The shoulders are located at the same level as the bottom of the C-shape rails 305 and 306, but may be at a level which is slightly higher (may be up to 10 mm, but preferably no more than 5 mm) or slightly lower (may be up to 10 mm, but preferably no more than 5 mm). A plate 320 extends substantially the entire length of the housing 314 within the housing 314. The plate 320 has opposing sides 321 and 322. Each side 321 and 322 is castellated (only two shown 321a and 322a). The tops of the castellations 321a, 322a on each side 321 and 322 are welded to the sidewalls 315 and 316 respectively, to form spaces (only two shown 321b and 322b) between adjacent castellations.
Referring back to FIG. 3, the castellations 331 in the body 325 of the inner housing 323 are vertically slideably arranged in the spaces 321b and 322b formed between the plate 320, the castellations 321a and 322b and the respective sidewalls 321 and 322 of the housing 314. The neck 326 is vertically slideably arranged in the slot 319 in the housing 314. An inflatable bladder 339 is fixed to the bottom face of the plate 320 and is linked to the hose 338. Return springs (340, only one shown) are spaced along the length of the central clamp 314 between the bottom plate 324 of the inner housing 323 and the bottom plate 316a of the outer housing 314.
Referring to FIGS. 3F to 3K, the screen assembly 400 comprises a panel 401 made from steel, aluminum or plastics material having a plurality of triangular apertures 402 between two imperforate side areas 403 and (not shown). A layer of screening material 404, such as wire mesh is adhered to the panel 401 using a hot melt glue, powder adhesive, staples, sewing material or other means. The layer of screening material 404 may comprise one, two or three more layers of wire mesh. The panel 401 is welded to a plurality of elements to form a support 405. Although, the support 405 may at least partly be made integrally with the panel 401 by folding portions of the panel 401, as disclosed in PCT Publication No. WO 01/76719 and herein above with reference to FIG. 3G. The plurality of elements comprises two side strips 406 and 407 which are welded to sides of the panel 401. A rear end 408 of the panel 401 has a strip of steel 410 welded thereto which has a bottom portion folded inwardly and downwardly to form a lip 409 for abutting another screen assembly provided with a lap. A front end 411 of the panel 401 has a strip of steel 412 welded thereto and has a bottom portion folded outwardly and folded back on itself to form a lap 413. A plurality of ribs 414 arranged between sides 406 and 407 are welded to the panel 401 and to the sides 406 and 407. Each rib 414 takes the form of a “lazy 7” which increases its rigidity. It is an aspect of the invention to have a screen assembly comprising at least one rib which is formed in the shape of a lazy 7 to increase the rigidity of the screen assembly. The ribs 414 may be arranged along solid parts of the panel 401, so that the apertures 402 are not obscured. A rail 416 is arranged along a central line of the screen assembly 400 in central recesses 415 in the ribs 414 and the strips of steel 410 and 412. The rail 416 is welded to the ribs 414 and strips of steel 410 and 412. The rail 416 is of uniform section and extends the entire length of the screen assembly 400. The rail 416 comprises a top 417, sides 418 and 419, each side having an inwardly and upwardly turning part forming a slot 420 and two shoulders 421 and 422. The shoulders 421 and 422 are flush with the bottoms of the ribs 414 and the steel strips 410 and 412. It should be noted that, it is preferred that the top 417 of the rail 416 is spaced from the panel 401, such that, in use, material filtered through the layers of screening material 404 and the apertures 405 in the panel 401 is substantially unobstructed and passes around the rail 416 and into a sump therebeneath.
FIG. 6 shows a shale shaker 700, like the shale shaker 300 described above, which has a basket 701 with an open bottom 704. Screen assemblies 720, 721 are located within rails 705, 706. Inflatable bladders 707, 708 are like the bladders 307, 308 described above. A central support 711 is mounted on a front support 709 and a similar rear support 709a beneath the screen assembly 721). Any suitable number of supports for the central support 711 may be used either at an angle to the central support of parallel with it and beneath it. Compressed air is supplied to the bladders 707, 708 via an air supply 704. Screened fluid flows through the screen assemblies 720, 721, through openings 709a, 709b, and then through the open bottom 704 into a typical receptacle or container.
The screen assemblies 720, 721 are like the screen assembly 400, described above, but the channel member 722 has no in-turned edges or shoulders as does the screen assembly 400 so that the top member 714 easily slide into and out of the channel member 722 during screen installation and removal. Alternatively, a central support may be used with a suitably sized and configured top member to fit between shoulders like the shoulders 421, 422 of the screen assembly 400. Optionally the screen assemblies 720, 721 have a plurality of ribs 716 like the ribs 414, FIG. 3G. Front members 717 facilitate handling and manipulation of the screen assemblies. FIGS. 7C-7E show a channel member 722a similar to the channel member 722, FIG. 7A, in the screen assembly 720. The channel member 722a is formed by two spaced-apart members 722b, 722c which abut ends of ribs 716.
FIGS. 8A and 8B show steps in the installation of a screen assembly according to the present invention using a center support and side bladders of a vibratory separator or shale shaker. A shaker 730 (shown partially) has opposed channels 731 connected to basket side walls 738 from which are supported inflatable side bladders 732 and within which are positioned one or more screen assemblies like the screen assembly 734 (which can be any screen assembly according to the present invention). A central support 733 has a top member 735 (e.g., but not limited to, like the central supports of FIGS. 6, 15, and 16) positioned within a recess (or channel member) 736. Prior to inflation of the bladders 732 (FIG. 8A), the screen assembly is in its original non-installed condition, which may be generally flat. As shown FIG. 8B, upon inflation of the bladders 732, the sides of the screen assembly 734 are pushed down producing a “crowned” screen assembly with a mid-portion higher than the sides.
FIGS. 10A and 10B show screen assembly 760 according to the present invention which has an optional outer frame 761 and a central channel 762 that functions like the channel members 722, 743, and 756 in conjunction with a central support (e.g. but not limited to, central supports as in FIGS. 6, 8A, 15 and 16). In certain aspects the screen assembly 760 is produced with any of the systems disclosed in U.S. applications Ser. No. 09/517,212 filed Mar. 2, 2000; Ser. No. 10/037,474 filed Oct. 19, 2001; Ser. No. 09/454,722, filed Dec. 4, 1999 and Ser. No. 10/087,025 filed Oct. 19, 2001—all co-owned with the present invention and incorporated fully herein for all purposes.
FIG. 12C shows a screen assembly 780a, like the screen assembly 780, but with a hollow central tube 788 instead of the solid rod 787. The tube 788 may be flexible or rigid.
FIGS. 13A and 13B show a screen assembly 780 according to the present invention like the screen assembly 780, FIG. 12A (like numerals indicate like parts) but with side rods 790a instead of side bars 782 and with a central flat piece 790b instead of the rod 787. In certain aspects the central flat piece is like the central member 772, FIG. 11A. Optionally, hollow and/or flexible tubes may be used for the side rods 790a.
The tongue 14 and/or the lower portion 18 may be formed by folding part of the frame back on itself. As shown in FIG. 14B a part 14b of a tongue 14 is folded over a part 14c, creating a rounded end part 14a. A part 18b of a lower portion 18 is folded over a part 18c, creating a rounded end part 18a.
FIG. 14B illustrates the sealing contact between the two screens 10 and 12. A part 14d of the screen assembly 12 sealingly contacts a part 16a of the screen assembly 10. An upper surface of the part 14c of the tongue 14 sealingly contacts a lower surface of a part 16b of the end 16. In certain aspects both of these sealing contacts are line contacts along substantially all of the ends of the adjacent screen assemblies.
In certain prior art devices when screen assemblies (which are prior art screen assemblies) as shown in FIGS. 14A and 14B abut each other and are clamped in place, the positive contact shown between portions 14c and 16b may or may not occur. When such screen assemblies are used in a method as described above (FIGS. 8A, 8B) the desired sealing contact between the portions 14c and 16b is facilitated and enhanced. Thus the present invention discloses a method for positioning a first screen assembly in abutting contact with a second screen assembly, the first screen assembly with a body with two opposed spaced-apart sides and a first end and a second end spaced-apart from the first end, the first end opposed to the second end, the body having a top and a bottom spaced-apart from the top, a tongue projecting from a location intermediate the top and the bottom of the first end of the body at a projection angle which is a non-perpendicular angle to the body, the tongue (in certain aspects, but not necessarily) formed of part of the body folded over on itself, the second end of the body having a projecting portion with a lower part configured and positioned for sealingly contacting a tongue like the tongue of the first end of an adjacent screen assembly, and the second end formed of part of the body, and the second screen assembly comprising a body with two opposed spaced-apart sides and a first end and a second end spaced-apart from the first end, the first end opposed to the second end, the body having a top and a bottom spaced-apart from the top, a tongue projecting from a location intermediate the top and the bottom of the first end of the body at a projection angle which is a non-perpendicular angle to the body, the tongue with a portion of the first tongue sealingly abutting a lower non-vertical surface of part of the second end formed of part of the body folded over on itself, the second end of the body having a projecting portion with a lower part configured and positioned for sealingly contacting a tongue like the tongue of the first end of an adjacent screen assembly, and the second end formed of part of the body, the method including moving the first screen assembly so that the first tongue sealingly contacts the second end.
In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein and those covered by the appended claims are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited in any of the following claims is to be understood as referring to all equivalent elements or steps. The following claims are intended to cover the invention as broadly as legally possible in whatever form it may be utilized. The invention claimed herein is new and novel in accordance with 35 U.S.C. §102 and satisfies the conditions for patentability in §102. The invention claimed herein is not obvious in accordance with 35 U.S.C. §103 and satisfies the conditions for patentability in §103. This specification and the claims that follow are in accordance with all of the requirements of 35 U.S.C. §112. The inventor may rely on the Doctrine of Equivalents to determine and assess the scope of their invention and of the claims that follow as they may pertain to apparatus not materially departing from, but outside of, the literal scope of the invention as set forth in the following claims. Any patent or patent application referred to herein is incorporated fully herein for all purposes.
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