CA2528542A1 - Screen assembly for a vibratory separator - Google Patents
Screen assembly for a vibratory separator Download PDFInfo
- Publication number
- CA2528542A1 CA2528542A1 CA 2528542 CA2528542A CA2528542A1 CA 2528542 A1 CA2528542 A1 CA 2528542A1 CA 2528542 CA2528542 CA 2528542 CA 2528542 A CA2528542 A CA 2528542A CA 2528542 A1 CA2528542 A1 CA 2528542A1
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- CA
- Canada
- Prior art keywords
- frame
- perforated plate
- screen assembly
- tabs
- attached
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
- B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
- B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
- B07B1/4618—Manufacturing of screening surfaces
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B1/00—Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like
- B07B1/46—Constructional details of screens in general; Cleaning or heating of screens
- B07B1/4609—Constructional details of screens in general; Cleaning or heating of screens constructional details of screening surfaces or meshes
- B07B1/4663—Multi-layer screening surfaces
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Combined Means For Separation Of Solids (AREA)
Abstract
A pretensioned screen assembly for a vibratory separator includes a perforated plate for supporting screening material, with the perforated plate having downwardly extending L-shaped tabs. The tabs have a vertical portion that extends along and attaches to a side of a generally rectangular supporting frame. The tabs further have a horizontal portion that extends along a bottom of the frame. The tabs are attached at least to frame members that are most susceptible to high frequency vibratory forces. The plate is thereby more securely attached to the frame as compared to conventional perforated plates which are attached only to a top of the frame. Further the tabs structurally reinforce the frame members to which they are attached. Consequently, the screen assembly is more resistant to separation of the screen assembly components caused by vibration-induced flexing.
Description
1 "SCREEN ASSEMBLY FOR A VIBRATORY SEPARATOR"
2
3 FIELD OF THE INVENTION
4 The invention relates to screens and in particular to a screen assembly for a vibratory separator such as a shale shaker.
8 Drilling mud is used while drilling oil and natural gas wells on a 9 drilling rig to control subsurface pressures, lubricate the drill bit, stabilize the wellbore, and carry cuttings and other debris to the surface, among other 11 functions. The drilling mud is pumped through a drill string and out of a drill bit, 12 then returned to the surface through the annular space between the drill string 13 and the wellbore. At the surface, cuttings and other solids that are entrained in 14 the mud are typically separated from the mud by a vibrating screen separator called a shale shaker.
16 Shale shakers include a lower stationary base, called an under flow 17 pan, and an upper vibratable basket that has connected to it a high frequency 18 linear angular motion or rotary vibratory motor. Mounted generally horizontally in 19 the basket is one or more screen assemblies having one or more layers of tensioned screening material. In use, solids-laden mud flows onto one end of the 21 screen deck and solids retained by the screening material are conveyed by 22 vibratory action to the other end where they are discharged. Fluids and small 23 particles pass through the screening material and are collected in a tank system 24 for further processing and reuse in the active system.
1 Screen assemblies can be distinguished by the way that they 2 provide tensioned screening material. One system is to use hook strips on the 3 basket sides of the screening material in association with tensioning mechanisms 4 on the shale shaker. Alternatively, pretensioned screen assemblies include tensioned screening material attached to a rigid perforated plate, which is in turn 6 attached to a generally rectangular structural frame. The perforated plate 7 supports the screening material and contains a plurality of openings to permit the 8 screened fluid to collect beneath the screening assembly. The frame is used to 9 mount the screen assembly onto corresponding support rails of the basket and the sides of the screening assembly are secured thereto. For example, wedge 11 blocks can be wedged between the top periphery of the screen assembly and 12 wedge angles extending radially inwardly from sides of the screen basket.
The 13 sides of the screening assembly are thereby securely sandwiched between the 14 support rails and the wedge blocks.
In one type of construction, the screening material layers are 16 bonded to the perforated plate, which is in turn bonded to the top surface of the 17 frame to form an integral screen assembly. The screen assembly is subject to 18 tremendous stresses caused by the vibratory machinery. In particular, upward 19 and downward stroking motion of the vibratory motor causes the screen assembly to oscillate between the secured sides. In other words, the unsecured 21 area of the screening assembly can vibrate at greater amplitude than the sides, 22 thereby causing out of plane flexing. Such flexing eventually results in failure of 23 the bonding of the perforated plate to the frame and the screen material, as well 24 as a loss of structural integrity of the screen material, the perforated panel and the frame. In general, greater flexing occurs with greater g-forces. Further, as 1 drilling mud flows over the screens, the upward stroking motion drives the mud 2 into the screen with the impinged mud creating additional reactive force against 3 the downward stroking motion.
4 Flexing of the screening assembly is a major cause of early deterioration of pretensioned screens, such as separation of components of the 6 screening assembly, contributing greatly to increased operational costs of the 7 shale shaker due to the man-hours required to replace the screen, loss of rig 8 operating time, and cost of replacement screens. To increase the rigidity of the 9 screening assembly for withstanding flexing forces, pretensioned screens are typically made of thick structural tubing and thick perforated plates. This 11 construction, however, results in high manufacturing costs and makes the 12 screening assembly heavy and difficult to handle. While texturing of the bonding 13 surface of perforated plate has been used to increase the bonding strength 14 between the perforated plate and the frame, this approach has not proven to be totally adequate.
16 There is, therefore, a need in the art for an improved screen for a 17 vibratory separator.
2 A screen assembly for a vibratory separator is provided whereby a 3 perforated plate for supporting screening material is more securely attached to a 4 frame as compared to conventional screen assemblies. Consequently, the screen assembly is more resistant to damage caused by out of plane flexing of 6 the screen assembly when subjected to high frequency vibratory forces in the 7 vibratory separator.
8 In a broad aspect of the invention, the perforated plate of the 9 screening assembly is attached not only to a top of the frame, as with conventional screening assemblies, but also to sides of the frame, and in 11 particular at least to sides of frame members that are most susceptible to flexing.
12 The attachment of the perforated plate to sides of the frame thereby provides for 13 more secure attachment, and also structurally reinforces the frame members to 14 which the perforated plate is attached.
Accordingly, in an embodiment of the invention there is provided a 16 screening assembly comprising a generally rectangular outer frame section, a 17 perforated plate attached to the frame, and one or more layers of screening 18 material supported on and attached to the perforated plate. The outer frame 19 section includes a pair of spaced apart longitudinal side members and a pair of spaced apart transverse end members, where the longitudinal side members are 21 to be securely mounted on a vibratable basket of a vibratory separator. The 22 perforated plate includes a substantially planar portion for supporting the 23 screening material, with the planar portion having a plurality of openings formed 24 therein. The perforated plate further includes a pair of opposing tabs extending downwardly from the planar portion, with the tabs having a vertical portion.
The 1 planar portion of the perforated plate is supported on and attached to a top of the 2 frame with the vertical portion of the tabs extending along and attached to a side 3 of the transverse end members.
4 The tabs can be further configured to be L-shaped tabs which additionally extend along a bottom of the transverse end members.
6 Additional aspects relating to the construction of the frame are also 7 disclosed.
8 Drilling mud is used while drilling oil and natural gas wells on a 9 drilling rig to control subsurface pressures, lubricate the drill bit, stabilize the wellbore, and carry cuttings and other debris to the surface, among other 11 functions. The drilling mud is pumped through a drill string and out of a drill bit, 12 then returned to the surface through the annular space between the drill string 13 and the wellbore. At the surface, cuttings and other solids that are entrained in 14 the mud are typically separated from the mud by a vibrating screen separator called a shale shaker.
16 Shale shakers include a lower stationary base, called an under flow 17 pan, and an upper vibratable basket that has connected to it a high frequency 18 linear angular motion or rotary vibratory motor. Mounted generally horizontally in 19 the basket is one or more screen assemblies having one or more layers of tensioned screening material. In use, solids-laden mud flows onto one end of the 21 screen deck and solids retained by the screening material are conveyed by 22 vibratory action to the other end where they are discharged. Fluids and small 23 particles pass through the screening material and are collected in a tank system 24 for further processing and reuse in the active system.
1 Screen assemblies can be distinguished by the way that they 2 provide tensioned screening material. One system is to use hook strips on the 3 basket sides of the screening material in association with tensioning mechanisms 4 on the shale shaker. Alternatively, pretensioned screen assemblies include tensioned screening material attached to a rigid perforated plate, which is in turn 6 attached to a generally rectangular structural frame. The perforated plate 7 supports the screening material and contains a plurality of openings to permit the 8 screened fluid to collect beneath the screening assembly. The frame is used to 9 mount the screen assembly onto corresponding support rails of the basket and the sides of the screening assembly are secured thereto. For example, wedge 11 blocks can be wedged between the top periphery of the screen assembly and 12 wedge angles extending radially inwardly from sides of the screen basket.
The 13 sides of the screening assembly are thereby securely sandwiched between the 14 support rails and the wedge blocks.
In one type of construction, the screening material layers are 16 bonded to the perforated plate, which is in turn bonded to the top surface of the 17 frame to form an integral screen assembly. The screen assembly is subject to 18 tremendous stresses caused by the vibratory machinery. In particular, upward 19 and downward stroking motion of the vibratory motor causes the screen assembly to oscillate between the secured sides. In other words, the unsecured 21 area of the screening assembly can vibrate at greater amplitude than the sides, 22 thereby causing out of plane flexing. Such flexing eventually results in failure of 23 the bonding of the perforated plate to the frame and the screen material, as well 24 as a loss of structural integrity of the screen material, the perforated panel and the frame. In general, greater flexing occurs with greater g-forces. Further, as 1 drilling mud flows over the screens, the upward stroking motion drives the mud 2 into the screen with the impinged mud creating additional reactive force against 3 the downward stroking motion.
4 Flexing of the screening assembly is a major cause of early deterioration of pretensioned screens, such as separation of components of the 6 screening assembly, contributing greatly to increased operational costs of the 7 shale shaker due to the man-hours required to replace the screen, loss of rig 8 operating time, and cost of replacement screens. To increase the rigidity of the 9 screening assembly for withstanding flexing forces, pretensioned screens are typically made of thick structural tubing and thick perforated plates. This 11 construction, however, results in high manufacturing costs and makes the 12 screening assembly heavy and difficult to handle. While texturing of the bonding 13 surface of perforated plate has been used to increase the bonding strength 14 between the perforated plate and the frame, this approach has not proven to be totally adequate.
16 There is, therefore, a need in the art for an improved screen for a 17 vibratory separator.
2 A screen assembly for a vibratory separator is provided whereby a 3 perforated plate for supporting screening material is more securely attached to a 4 frame as compared to conventional screen assemblies. Consequently, the screen assembly is more resistant to damage caused by out of plane flexing of 6 the screen assembly when subjected to high frequency vibratory forces in the 7 vibratory separator.
8 In a broad aspect of the invention, the perforated plate of the 9 screening assembly is attached not only to a top of the frame, as with conventional screening assemblies, but also to sides of the frame, and in 11 particular at least to sides of frame members that are most susceptible to flexing.
12 The attachment of the perforated plate to sides of the frame thereby provides for 13 more secure attachment, and also structurally reinforces the frame members to 14 which the perforated plate is attached.
Accordingly, in an embodiment of the invention there is provided a 16 screening assembly comprising a generally rectangular outer frame section, a 17 perforated plate attached to the frame, and one or more layers of screening 18 material supported on and attached to the perforated plate. The outer frame 19 section includes a pair of spaced apart longitudinal side members and a pair of spaced apart transverse end members, where the longitudinal side members are 21 to be securely mounted on a vibratable basket of a vibratory separator. The 22 perforated plate includes a substantially planar portion for supporting the 23 screening material, with the planar portion having a plurality of openings formed 24 therein. The perforated plate further includes a pair of opposing tabs extending downwardly from the planar portion, with the tabs having a vertical portion.
The 1 planar portion of the perforated plate is supported on and attached to a top of the 2 frame with the vertical portion of the tabs extending along and attached to a side 3 of the transverse end members.
4 The tabs can be further configured to be L-shaped tabs which additionally extend along a bottom of the transverse end members.
6 Additional aspects relating to the construction of the frame are also 7 disclosed.
5 2 In drawings which are intended to illustrate embodiments of the 3 invention and which are not intended to limit the scope of the invention:
4 Figure 1 is a perspective view of one embodiment of a screen assembly according to the present invention, with part of the screening material
4 Figure 1 is a perspective view of one embodiment of a screen assembly according to the present invention, with part of the screening material
6 removed for viewing the perforated plate and the frame;
7 Figure 2 is a cross-sectional side view taken along lines II-II of Fig.
8 1 and with the cross members removed;
9 Figure 3 is an exploded view of Fig. 1;
Figure 4 is a cross-sectional side view of another embodiment of a 11 screen assembly according to the present invention;
12 Figure 5 is a partial perspective and exploded view of the frame and 13 perforated plate of Fig. 4;
14 Figures 6A is a top view of an outer frame section of the screen assembly of Fig. 1;
16 Figure 6B is a top view of the hollow structural tubing used to form 17 the outer frame section of Fig. 6A;
18 Figure 6C is a close-up view of a notched area of Fig. 6B;
19 Figure 6D is a sectional view taken along lines VI-VI of Fig. 6A;
Figure 7 is an exploded partial perspective view of intersecting 21 cross members of the frame of the screen assembly of Fig. 1; and 22 Figure 8 is a cross-sectional side view of yet another embodiment 23 of a screen assembly of the present invention.
2 With reference to Figs. 1-3, an embodiment of a screen assembly 3 10 for a vibratory separator generally comprises a frame 12, a perforated plate 14 4 and one or more layers of screening material 16. The screening material 16 is supported on and attached to the perforated plate 14, with the perforated plate 14 6 in turn being supported on and attached to the frame 12. As described below, 7 the perforated plate 14 includes features that provide for more secure attachment 8 to the frame 12 as compared to conventional perforated plates, thereby 9 enhancing the structural integrity of the screen assembly 10 against vibratory forces.
11 In further detail, the frame 12 comprises a generally rectangular 12 outer frame section 18 having a pair of spaced apart longitudinal side members 13 20 and a pair of spaced apart transverse end members 22. In use, the screening 14 assembly 10 is mounted horizontally in a vibratable basket of a vibratory separator (not shown), with the longitudinal side members 20 being clamped or 16 otherwise secured to the basket. Linear angular or rotary vibratory forces are 17 applied to the basket, and hence the screening assembly 10, to cause material 18 on a top 24 of the screening material 16 to move generally longitudinally 19 therealong from one end 26 of the screening assembly 10 to another end 28.
As with conventional perforated plates, the perforated plate 14 21 comprises a planar portion 32 for supporting the screening material 16 22 thereupon, with the planar portion 32 having a plurality of holes or perforations 34 23 punched or otherwise formed therein. The perforations 34 can be of any suitable 24 shape and size to permit sufficient flow-through of screened fluid, while maintaining structural integrity of the perforated plate 14, as would be 1 appreciated by one skilled in the art. In addition, the perforated plate 14 includes 2 a pair of opposing tabs 36 having a vertical portion 38 extending downwardly 3 from transverse edges 40 of the planar portion 32. The tabs 36 may be formed, 4 for example, by downwardly bending a non-perforated periphery 42 of the planar portion 32.
6 The perforated plate 14 is fit over the frame 12 with the planar 7 portion 32 being supported by an adjacent top 44 of the frame 12, and the vertical 8 portion 38 of the tabs 36 adjacent outer sides 46 of the transverse end members 9 22 of the frame 12. The perforated plate 14 is attached with bonding material 48 to the adjacent surfaces of the frame 12 and the screening material 16 is in tum 11 bonded with bonding material 48 to the perforated plate 14, thereby forming an 12 integral screen assembly 10. As compared with conventional perforated plates, 13 which are bonded or otherwise attached to only to the top surface 44 of the frame 14 12, additional attachment of the perforated plate 14 to the outer sides 46 of the transverse end members 22 by the tabs 36 provides for more secure attachment 16 of the perforated plate 14 to the frame 12. Consequently, the perforated plate 14 17 is more resistant to vibratory detachment from frame 12 upon flexing of the 18 screening assembly 10 in response to upward and downward forces imposed by 19 the vibratory machinery. Further, the tabs 36 of the perforated plate 14 structurally reinforce or stiffen the transverse end members 22 of the frame 12, 21 thereby reducing the risk of bond failure between the frame 12 and the perforated 22 plate 14, as well as between the perforated plate 14 and the screening material 23 16. Notably, the structural and functional advantages provided by the tabs 36 do 24 not significantly increase the weight of the screening assembly 10.
1 While the tabs 36 are preferably each a single tab 36 extending 2 along the entire transverse length of the perforated plate 14, the tabs can also 3 extend partially along the transverse length of the perforated plate 14, and can 4 also be a plurality of spaced apart tabs.
Tabs 36 extending along the longitudinal side members 20 can also 6 be provided, although this is generally not necessary as the sides of the screen 7 assembly 10 are typically held in position by wedge blocks.
8 With reference to Figs. 4 and 5, to further improve the security of 9 the attachment of the perforated plate 14 to the frame 12, the tabs 36 can be L-shaped tabs 36 further having an inwardly directed horizontal portion 50 that 11 extends along a bottom 52 of the transverse end members 22. The horizontal 12 portion 50 thereby vertically clamps the perforated plate 14 onto the transverse 13 end members 22 of the frame 12 and further structurally reinforces the transverse 14 end members 22. While it is not necessary to attach the horizontal portion 50 to the bottom 52 of the transverse end members 22, the overall process of bonding 16 the perforated plate 14 to the frame consequently results in bonding of the 17 horizontal portion 50, as described in detail below.
18 With further reference to Fig. 8, while the perforated plate 14 has 19 thus far been described as having the tabs 36 positioned to extend from the transverse edges 40 of the perforated plate 14, the tabs 36 may be also be 21 inwardly offset from the transverse edges 40 to attach to the vertical portion 38 to 22 an inner side 54 of the transverse end members 22. In this case, the tabs 36 can 23 be formed by welding or otherwise securely attaching the tabs underneath the 24 perforated plate 14.
1 The components of the screen assembly 10 can be of any suitable 2 fabrication and construction, as would be apparent to one skilled in the art. For 3 example, the frame 12 and the perforated plate 14 can be made of rigid yet 4 malleable material, such as mild steel. The screening material 16 can be made of stainless steel and can also include a plurality of layers of screening material 6 16, as particularly seen in Figs. 1-3. Such layers typically progress in mesh size 7 whereby a finer-meshed top layer 16a is supported by more coarsely-meshed 8 lower layers 16b, 16c. The top layer 16a thereby acts as a sizing screen while 9 the lower layers 16b, 16c act as structural layers to extend the life of the top layer 16a. To reduce wear, the lower layers 16b, 16c can be calendared, i.e.
flattened 11 where the wires of the screening material 16 intersect.
12 Preferably, the bonding material 48 is an epoxy thermosetting resin, 13 which can be heated to reversibly transition from a solid state to a flowable fluid 14 state for coating the surfaces of the components of the screen assembly 10.
Suitable epoxy includes, for example 10-7010 Corvel Gray (Rohm and Haas, 16 Philadelphia, PA) and Nap-Guard (DuPont, Mississauga, Ontario, Canada). As 17 an example of an assembly process, each of the frame 12 and the perforated 18 plate 14 can be separately coated with epoxy powder by pre-heating each 19 component in an oven to a suitable temperature and suspending the heated component into a fluidized epoxy powder bed as necessary to develop a coating 21 thereon. Upon return to ambient temperature, the fluid coating re-solidifies and 22 firmly adheres to the surfaces of the components. The epoxy-coated perforated 23 plate 14 is fit over the frame 12 and screening material 16 is placed over the 24 perforated plate 14. The entire assembly 10 is then subjected to a heat press at a suitable temperature to firmly bond the surfaces together to form an integral 1 screen assembly 10. To provide a better surface texture for bonding, the 2 surfaces can be abrasive grit blasted prior to epoxy powder coating.
3 Where L-shaped tabs 36 are used and with particular reference to 4 Fig. 5, prior to coating and bonding with epoxy, it may be desired to first fit the perforated plate 14 over the frame 12 by inserting a longitudinal side member 6 into channels 58 defined by the L-shaped tabs 36 and further sliding the frame 12 7 into the channels 58 to form a perforated plate-frame unit. The fitted perforated 8 plate 14 can then be attached to the frame 12 by coating the perforated plate-9 frame unit with epoxy thermosetting resin, such as described above.
Preferably, the epoxy has sufficient flow characteristics to enter between tightly adjacent 11 surfaces, such as 10-7010 Corvel Gray.
12 Although it is particularly contemplated to use bonding material 48 13 for attaching the screen assembly 10 components to form an integral unit, other 14 attachment means can be used alternatively or in addition to the bonding material 48, as would be appreciated by one skilled in the art. Other attachment means 16 can include, for example, tack welding, spot welding, screws, rivets, etc.
As an 17 example, where L-shaped tabs 36 are used, it may be desired to spot weld the 18 fitted perforated plate 14 to the frame 12 prior bonding, where in the bonding 19 process the epoxy or other bonding material may enter spaces between the tabs 36 and the frame 12 to effect bonding.
21 With reference to Figs. 6A-D, the outer frame section 18 can be 22 constructed of single piece of hollow structural tubing 60 having four spaced-23 apart corner notches 62, with each notch 62 forming an angle of about ninety 24 degrees extending from an outer wall 64 of the tubing 60. The outer frame section 18 is completed by inwardly bending the tubing 60 around the notches 1 to form a generally rectangular shape and securing the ends 66 together by 2 welding. The notches 62 are preferably formed by punch-cutting such that a top 3 edge 68 of each notch 62 is downwardly deformed, as shown in Fig. 6D.
4 Consequently, the corners 70 of the completed outer frame section 18 advantageously form a top pocket 72 for containing bonding material 48 used to 6 bond the perforated plate 14 to the frame 12, thereby making a more secure 7 bonding connection. In this case, welding on the top pocket 72 should be 8 avoided as welding material may fill the top pocket 72 that would otherwise 9 contain bonding material 48. Further, welding material on any top surface 44 of the frame 12 would potentially interfere with the fitting of the perforated panel 14 11 on the frame 12 if excess welding material is not removed.
12 With particular reference to Fig. 3, the frame can also include at 13 least one transverse or longitudinal cross member 74, 76 positioned within the 14 outer frame section 18. The cross member or members 74, 76 thus provide additional structural rigidity to the frame 12 and further support for the perforated 16 plate 14. The cross members 74, 76 can be fabricated from hollow structural 17 tubing, with the cross members 74, 76 being secured such as by welding to the 18 outer frame section 10 or to an oppositely oriented cross member 74, 76.
19 With further reference to Fig. 7, where both transverse cross members 74 and longitudinal cross members 76 are used, the cross members 21 74, 76 can be interlocked by complementary upward- and downward-facing 22 notches 80, 82 formed such as by punch-cutting.
23 Other suitable forms of the frame are also contemplated, as would 24 be apparent to one skilled in the art. For example, rather than having a generally rectangular outer frame, the frame can comprise a pair of spaced apart opposing 1 longitudinal sides that are connected by at least one transverse cross-bar to form 2 an H- or a ladder-type arrangement.
3 Although preferred embodiments of the invention have been 4 described in some detail herein above, those skilled in the art will recognize that various substitutions and modifications of the invention may be made without 6 departing from the scope of the invention as defined by the claims as defined 7 herein.
Figure 4 is a cross-sectional side view of another embodiment of a 11 screen assembly according to the present invention;
12 Figure 5 is a partial perspective and exploded view of the frame and 13 perforated plate of Fig. 4;
14 Figures 6A is a top view of an outer frame section of the screen assembly of Fig. 1;
16 Figure 6B is a top view of the hollow structural tubing used to form 17 the outer frame section of Fig. 6A;
18 Figure 6C is a close-up view of a notched area of Fig. 6B;
19 Figure 6D is a sectional view taken along lines VI-VI of Fig. 6A;
Figure 7 is an exploded partial perspective view of intersecting 21 cross members of the frame of the screen assembly of Fig. 1; and 22 Figure 8 is a cross-sectional side view of yet another embodiment 23 of a screen assembly of the present invention.
2 With reference to Figs. 1-3, an embodiment of a screen assembly 3 10 for a vibratory separator generally comprises a frame 12, a perforated plate 14 4 and one or more layers of screening material 16. The screening material 16 is supported on and attached to the perforated plate 14, with the perforated plate 14 6 in turn being supported on and attached to the frame 12. As described below, 7 the perforated plate 14 includes features that provide for more secure attachment 8 to the frame 12 as compared to conventional perforated plates, thereby 9 enhancing the structural integrity of the screen assembly 10 against vibratory forces.
11 In further detail, the frame 12 comprises a generally rectangular 12 outer frame section 18 having a pair of spaced apart longitudinal side members 13 20 and a pair of spaced apart transverse end members 22. In use, the screening 14 assembly 10 is mounted horizontally in a vibratable basket of a vibratory separator (not shown), with the longitudinal side members 20 being clamped or 16 otherwise secured to the basket. Linear angular or rotary vibratory forces are 17 applied to the basket, and hence the screening assembly 10, to cause material 18 on a top 24 of the screening material 16 to move generally longitudinally 19 therealong from one end 26 of the screening assembly 10 to another end 28.
As with conventional perforated plates, the perforated plate 14 21 comprises a planar portion 32 for supporting the screening material 16 22 thereupon, with the planar portion 32 having a plurality of holes or perforations 34 23 punched or otherwise formed therein. The perforations 34 can be of any suitable 24 shape and size to permit sufficient flow-through of screened fluid, while maintaining structural integrity of the perforated plate 14, as would be 1 appreciated by one skilled in the art. In addition, the perforated plate 14 includes 2 a pair of opposing tabs 36 having a vertical portion 38 extending downwardly 3 from transverse edges 40 of the planar portion 32. The tabs 36 may be formed, 4 for example, by downwardly bending a non-perforated periphery 42 of the planar portion 32.
6 The perforated plate 14 is fit over the frame 12 with the planar 7 portion 32 being supported by an adjacent top 44 of the frame 12, and the vertical 8 portion 38 of the tabs 36 adjacent outer sides 46 of the transverse end members 9 22 of the frame 12. The perforated plate 14 is attached with bonding material 48 to the adjacent surfaces of the frame 12 and the screening material 16 is in tum 11 bonded with bonding material 48 to the perforated plate 14, thereby forming an 12 integral screen assembly 10. As compared with conventional perforated plates, 13 which are bonded or otherwise attached to only to the top surface 44 of the frame 14 12, additional attachment of the perforated plate 14 to the outer sides 46 of the transverse end members 22 by the tabs 36 provides for more secure attachment 16 of the perforated plate 14 to the frame 12. Consequently, the perforated plate 14 17 is more resistant to vibratory detachment from frame 12 upon flexing of the 18 screening assembly 10 in response to upward and downward forces imposed by 19 the vibratory machinery. Further, the tabs 36 of the perforated plate 14 structurally reinforce or stiffen the transverse end members 22 of the frame 12, 21 thereby reducing the risk of bond failure between the frame 12 and the perforated 22 plate 14, as well as between the perforated plate 14 and the screening material 23 16. Notably, the structural and functional advantages provided by the tabs 36 do 24 not significantly increase the weight of the screening assembly 10.
1 While the tabs 36 are preferably each a single tab 36 extending 2 along the entire transverse length of the perforated plate 14, the tabs can also 3 extend partially along the transverse length of the perforated plate 14, and can 4 also be a plurality of spaced apart tabs.
Tabs 36 extending along the longitudinal side members 20 can also 6 be provided, although this is generally not necessary as the sides of the screen 7 assembly 10 are typically held in position by wedge blocks.
8 With reference to Figs. 4 and 5, to further improve the security of 9 the attachment of the perforated plate 14 to the frame 12, the tabs 36 can be L-shaped tabs 36 further having an inwardly directed horizontal portion 50 that 11 extends along a bottom 52 of the transverse end members 22. The horizontal 12 portion 50 thereby vertically clamps the perforated plate 14 onto the transverse 13 end members 22 of the frame 12 and further structurally reinforces the transverse 14 end members 22. While it is not necessary to attach the horizontal portion 50 to the bottom 52 of the transverse end members 22, the overall process of bonding 16 the perforated plate 14 to the frame consequently results in bonding of the 17 horizontal portion 50, as described in detail below.
18 With further reference to Fig. 8, while the perforated plate 14 has 19 thus far been described as having the tabs 36 positioned to extend from the transverse edges 40 of the perforated plate 14, the tabs 36 may be also be 21 inwardly offset from the transverse edges 40 to attach to the vertical portion 38 to 22 an inner side 54 of the transverse end members 22. In this case, the tabs 36 can 23 be formed by welding or otherwise securely attaching the tabs underneath the 24 perforated plate 14.
1 The components of the screen assembly 10 can be of any suitable 2 fabrication and construction, as would be apparent to one skilled in the art. For 3 example, the frame 12 and the perforated plate 14 can be made of rigid yet 4 malleable material, such as mild steel. The screening material 16 can be made of stainless steel and can also include a plurality of layers of screening material 6 16, as particularly seen in Figs. 1-3. Such layers typically progress in mesh size 7 whereby a finer-meshed top layer 16a is supported by more coarsely-meshed 8 lower layers 16b, 16c. The top layer 16a thereby acts as a sizing screen while 9 the lower layers 16b, 16c act as structural layers to extend the life of the top layer 16a. To reduce wear, the lower layers 16b, 16c can be calendared, i.e.
flattened 11 where the wires of the screening material 16 intersect.
12 Preferably, the bonding material 48 is an epoxy thermosetting resin, 13 which can be heated to reversibly transition from a solid state to a flowable fluid 14 state for coating the surfaces of the components of the screen assembly 10.
Suitable epoxy includes, for example 10-7010 Corvel Gray (Rohm and Haas, 16 Philadelphia, PA) and Nap-Guard (DuPont, Mississauga, Ontario, Canada). As 17 an example of an assembly process, each of the frame 12 and the perforated 18 plate 14 can be separately coated with epoxy powder by pre-heating each 19 component in an oven to a suitable temperature and suspending the heated component into a fluidized epoxy powder bed as necessary to develop a coating 21 thereon. Upon return to ambient temperature, the fluid coating re-solidifies and 22 firmly adheres to the surfaces of the components. The epoxy-coated perforated 23 plate 14 is fit over the frame 12 and screening material 16 is placed over the 24 perforated plate 14. The entire assembly 10 is then subjected to a heat press at a suitable temperature to firmly bond the surfaces together to form an integral 1 screen assembly 10. To provide a better surface texture for bonding, the 2 surfaces can be abrasive grit blasted prior to epoxy powder coating.
3 Where L-shaped tabs 36 are used and with particular reference to 4 Fig. 5, prior to coating and bonding with epoxy, it may be desired to first fit the perforated plate 14 over the frame 12 by inserting a longitudinal side member 6 into channels 58 defined by the L-shaped tabs 36 and further sliding the frame 12 7 into the channels 58 to form a perforated plate-frame unit. The fitted perforated 8 plate 14 can then be attached to the frame 12 by coating the perforated plate-9 frame unit with epoxy thermosetting resin, such as described above.
Preferably, the epoxy has sufficient flow characteristics to enter between tightly adjacent 11 surfaces, such as 10-7010 Corvel Gray.
12 Although it is particularly contemplated to use bonding material 48 13 for attaching the screen assembly 10 components to form an integral unit, other 14 attachment means can be used alternatively or in addition to the bonding material 48, as would be appreciated by one skilled in the art. Other attachment means 16 can include, for example, tack welding, spot welding, screws, rivets, etc.
As an 17 example, where L-shaped tabs 36 are used, it may be desired to spot weld the 18 fitted perforated plate 14 to the frame 12 prior bonding, where in the bonding 19 process the epoxy or other bonding material may enter spaces between the tabs 36 and the frame 12 to effect bonding.
21 With reference to Figs. 6A-D, the outer frame section 18 can be 22 constructed of single piece of hollow structural tubing 60 having four spaced-23 apart corner notches 62, with each notch 62 forming an angle of about ninety 24 degrees extending from an outer wall 64 of the tubing 60. The outer frame section 18 is completed by inwardly bending the tubing 60 around the notches 1 to form a generally rectangular shape and securing the ends 66 together by 2 welding. The notches 62 are preferably formed by punch-cutting such that a top 3 edge 68 of each notch 62 is downwardly deformed, as shown in Fig. 6D.
4 Consequently, the corners 70 of the completed outer frame section 18 advantageously form a top pocket 72 for containing bonding material 48 used to 6 bond the perforated plate 14 to the frame 12, thereby making a more secure 7 bonding connection. In this case, welding on the top pocket 72 should be 8 avoided as welding material may fill the top pocket 72 that would otherwise 9 contain bonding material 48. Further, welding material on any top surface 44 of the frame 12 would potentially interfere with the fitting of the perforated panel 14 11 on the frame 12 if excess welding material is not removed.
12 With particular reference to Fig. 3, the frame can also include at 13 least one transverse or longitudinal cross member 74, 76 positioned within the 14 outer frame section 18. The cross member or members 74, 76 thus provide additional structural rigidity to the frame 12 and further support for the perforated 16 plate 14. The cross members 74, 76 can be fabricated from hollow structural 17 tubing, with the cross members 74, 76 being secured such as by welding to the 18 outer frame section 10 or to an oppositely oriented cross member 74, 76.
19 With further reference to Fig. 7, where both transverse cross members 74 and longitudinal cross members 76 are used, the cross members 21 74, 76 can be interlocked by complementary upward- and downward-facing 22 notches 80, 82 formed such as by punch-cutting.
23 Other suitable forms of the frame are also contemplated, as would 24 be apparent to one skilled in the art. For example, rather than having a generally rectangular outer frame, the frame can comprise a pair of spaced apart opposing 1 longitudinal sides that are connected by at least one transverse cross-bar to form 2 an H- or a ladder-type arrangement.
3 Although preferred embodiments of the invention have been 4 described in some detail herein above, those skilled in the art will recognize that various substitutions and modifications of the invention may be made without 6 departing from the scope of the invention as defined by the claims as defined 7 herein.
Claims (13)
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:
1. A screen assembly for a vibratory separator comprising:
a generally rectangular outer frame section having a pair of spaced apart longitudinal side members and a pair of spaced apart transverse end members;
a perforated plate having a substantially planar portion with a plurality of openings formed therein, the planar portion being supported on a top of the outer frame section and attached thereto, the perforated plate further having a pair of opposing L-shaped tabs extending downwardly from the planar portion, the tabs having a vertical portion and a horizontal portion, the vertical portion extending along an outer side of the transverse end members of the outer frame section and attached thereto, the horizontal portion extending along a bottom of the transverse end members of the frame; and one or more layers of screening material supported on a top of the planar portion of the perforated plate and attached thereto.
a generally rectangular outer frame section having a pair of spaced apart longitudinal side members and a pair of spaced apart transverse end members;
a perforated plate having a substantially planar portion with a plurality of openings formed therein, the planar portion being supported on a top of the outer frame section and attached thereto, the perforated plate further having a pair of opposing L-shaped tabs extending downwardly from the planar portion, the tabs having a vertical portion and a horizontal portion, the vertical portion extending along an outer side of the transverse end members of the outer frame section and attached thereto, the horizontal portion extending along a bottom of the transverse end members of the frame; and one or more layers of screening material supported on a top of the planar portion of the perforated plate and attached thereto.
2. The screen assembly of claim 1 wherein the attachment is by a bonding material.
3. The screen assembly of claim 2 wherein the bonding material is epoxy thermosetting resin.
4. The screen assembly of claims 2 or 3 wherein the perforated plate is further attached to the frame by spot welding.
5. The screen assembly any one of claims 1-4 wherein the outer frame section is made of a linear piece of hollow structural tubing having four V-shaped corner notches formed therein, the V-shaped notches forming an angle of about 90 degrees extending from an outer wall of the tubing, the outer frame section being formed by inwardly bending the linear tubing around the V-shaped corner notches.
6. The screen assembly of claim 5 wherein the notches are punch cut so as to form a depression in a top of each corner of the formed frame.
7. The screen assembly of any one of claims 1-6, the frame further comprising:
one or more cross members positioned within the outer frame section and attached thereto.
one or more cross members positioned within the outer frame section and attached thereto.
8. The screen assembly of claim 7 wherein the one or more cross members includes:
a transverse cross member; or a longitudinal cross member; or a combination of a transverse cross member and a longitudinal cross member.
a transverse cross member; or a longitudinal cross member; or a combination of a transverse cross member and a longitudinal cross member.
9. The screen assembly of claim 8 wherein the transverse and longitudinal cross members interconnected therebetween.
10. The screen assembly of claim 9 wherein the transverse and longitudinal cross members are interconnected by complementary notches formed therein.
11. A perforated plate for supporting screening material in a screen assembly, the screen assembly for use in a vibratory separator, the screen assembly comprising a generally rectangular outer frame section having a pair of spaced apart longitudinal side members and a pair of spaced apart transverse end members; the perforated plate comprising:
a substantially planar portion with a plurality of openings formed therein, the planar portion for being supported on a top of the frame; and a pair of opposing L-shaped tabs extending downwardly from the planar portion, the tabs having a vertical portion and a horizontal portion, the vertical portion for extending along an outer side of the transverse end members when the planar portion is supported on the top of frame, the horizontal portion for extending along a bottom of the transverse end members when the planar portion is supported on the frame.
a substantially planar portion with a plurality of openings formed therein, the planar portion for being supported on a top of the frame; and a pair of opposing L-shaped tabs extending downwardly from the planar portion, the tabs having a vertical portion and a horizontal portion, the vertical portion for extending along an outer side of the transverse end members when the planar portion is supported on the top of frame, the horizontal portion for extending along a bottom of the transverse end members when the planar portion is supported on the frame.
12. A method of assembling the screen assembly of claim 1 comprising:
fitting the perforated plate over the frame by inserting a longitudinal side into channels defined by the L-shaped tabs and further sliding the frame into the channels to form a perforated plate-frame unit;
attaching the fitted perforated plate to the frame by bonding with epoxy thermosetting resin by coating the perforated plate-frame unit with the resin and subjecting the perforated plate-frame unit to a temperature that permits bonding;
placing the screening material over the perforated plate to form a screen assembly; and attaching the screening material to the perforated plate by subjecting the screen assembly to heat press at a temperature that permits bonding.
fitting the perforated plate over the frame by inserting a longitudinal side into channels defined by the L-shaped tabs and further sliding the frame into the channels to form a perforated plate-frame unit;
attaching the fitted perforated plate to the frame by bonding with epoxy thermosetting resin by coating the perforated plate-frame unit with the resin and subjecting the perforated plate-frame unit to a temperature that permits bonding;
placing the screening material over the perforated plate to form a screen assembly; and attaching the screening material to the perforated plate by subjecting the screen assembly to heat press at a temperature that permits bonding.
13. The method of claim 12 further comprising:
attaching the fitted perforated plate to the frame by spot welding prior to the attaching of the fitted perforated plate to the frame by bonding with epoxy thermosetting resin.
attaching the fitted perforated plate to the frame by spot welding prior to the attaching of the fitted perforated plate to the frame by bonding with epoxy thermosetting resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2528542 CA2528542A1 (en) | 2005-12-01 | 2005-12-01 | Screen assembly for a vibratory separator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2528542 CA2528542A1 (en) | 2005-12-01 | 2005-12-01 | Screen assembly for a vibratory separator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2528542A1 true CA2528542A1 (en) | 2007-06-01 |
Family
ID=38110510
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2528542 Abandoned CA2528542A1 (en) | 2005-12-01 | 2005-12-01 | Screen assembly for a vibratory separator |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2528542A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008038014A2 (en) * | 2006-09-29 | 2008-04-03 | United Wire Limited | Injection molded grid for saving screen frames |
| CN113751316A (en) * | 2021-09-23 | 2021-12-07 | 陕西竹园嘉原矿业有限公司 | Ore sorting unit is used in mining |
| CN113893599A (en) * | 2020-07-06 | 2022-01-07 | 河北冠能石油机械制造有限公司 | Vibrating screen mesh for a shale shaker |
| CN114505222A (en) * | 2022-01-29 | 2022-05-17 | 合肥开比锐精机科技有限公司 | High-purity clean silicon material classifying and screening device and using method thereof |
-
2005
- 2005-12-01 CA CA 2528542 patent/CA2528542A1/en not_active Abandoned
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008038014A2 (en) * | 2006-09-29 | 2008-04-03 | United Wire Limited | Injection molded grid for saving screen frames |
| WO2008038014A3 (en) * | 2006-09-29 | 2009-09-24 | United Wire Limited | Injection molded grid for saving screen frames |
| US8393474B2 (en) | 2006-09-29 | 2013-03-12 | United Wire Limited | Injection molded grid for saving screen frames |
| US9156061B2 (en) | 2006-09-29 | 2015-10-13 | United Wire Limited | Injection molded grid for saving screen frames |
| CN113893599A (en) * | 2020-07-06 | 2022-01-07 | 河北冠能石油机械制造有限公司 | Vibrating screen mesh for a shale shaker |
| CN113751316A (en) * | 2021-09-23 | 2021-12-07 | 陕西竹园嘉原矿业有限公司 | Ore sorting unit is used in mining |
| CN113751316B (en) * | 2021-09-23 | 2022-07-05 | 陕西竹园嘉原矿业有限公司 | Ore sorting unit is used in mining |
| CN114505222A (en) * | 2022-01-29 | 2022-05-17 | 合肥开比锐精机科技有限公司 | High-purity clean silicon material classifying and screening device and using method thereof |
| CN114505222B (en) * | 2022-01-29 | 2024-04-19 | 合肥开比锐精机科技有限公司 | High-purity clean silicon material classifying and screening device and application method thereof |
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| Date | Code | Title | Description |
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