Classifications

• • 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
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/01—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements
  • B01D29/012—Making filtering elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/01—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements
  • B01D29/05—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor with flat filtering elements supported
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D29/00—Filters with filtering elements stationary during filtration, e.g. pressure or suction filters, not covered by groups B01D24/00 - B01D27/00; Filtering elements therefor
  • B01D29/62—Regenerating the filter material in the filter
  • B01D29/70—Regenerating the filter material in the filter by forces created by movement of the filter element
  • B01D29/72—Regenerating the filter material in the filter by forces created by movement of the filter element involving vibrations
• • 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
• • 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
  • B07B2201/00—Details applicable to machines for screening using sieves or gratings
  • B07B2201/02—Fastening means for fastening screens to their frames which do not stretch or sag the screening surfaces

Definitions

• Drilling mud typically a mixture of clay, water and various additives
• Drilling mud is pumped down through a hollow drill string (pipe, drill collar, bit, etc.) into a well being drilled and exits through holes in the 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.
• the solids-laden mud is discharged over a shale shaker, a device which typically has a series of screens arranged in tiered or flat disposition with respect to each other.
• a vibrating screen may be formed from one or more layers of wire mesh.
• Wire mesh is generally described with reference to the diameter of the wires from which it is woven, the number wires per unit length (called the mesh count) and the shape or size of the openings between wires .
• Wire mesh comes in various grades . "Market” grade mesh generally has wires of relative large diameter. "Mill” grade has comparatively smaller diameter wires and “bolting cloth” has the smallest diameter wire. The type of mesh chosen depends on the application. Smaller diameter wires have less surface and thus less drag, resulting in greater flow rates. Smaller diameter wires also result, for a given opening size, in a larger percentage of open area over the total area of the screen, thus allowing greater flow rates and increased capacity.
• screens of bolting cloth tear more easily than market or mill grade screens, especially when used in harsh conditions such as drilling and mining operations .
• the smaller diameter wires tend to have less tensile strength and break more easily, and the finer mesh also tends not to retain its shape well .
• Most meshes suffer from what is termed “near sized particle blinding".
• wires separate enough to allow particles of substantially the same size or slightly larger than the openings to fall between the wires and become lodged, thus “blinding" the openings of the screen and reducing capacity of the screen . If a particle becomes lodged when the wires are at their maximum distance apart, it is almost impossible to dislodge the particle. Sometimes, however, wires will subsequently separate further to release the lodged particle.
• 4,033,865 describes layering two meshes in a manner that results in at least one wire of the lower of the two meshes bisecting each opening in the upper mesh.
• the openings in each mesh are at least twice as wide as the diameters of the wires and the lower mesh has openings the same size as or slightly larger than the openings in the upper mesh.
• the lower mesh when held tightly against the upper mesh, prevents particles from migrating far enough into an opening in the upper mesh to be trapped. Some relative movement of the layers also helps to dislodge particles caught in the upper layer.
• the two-layer arrangement has the further benefit of a finer "cutting point," allowing smaller particles to be separated out.
• a third "backing" layer of relatively coarse, mill grade mesh is often used to carry most of the load on the screen and to increase the tensile strength of the screen.
• a torn screen must be replaced or repaired.
• the screen layers are bonded to a rigid or semi-rigid support panel that has a pattern of large openings , forming on the screen a plurality of small cells of wire mesh.
• the mesh remaining within the cell in which the tear occurred is cut out and the cell is plugged.
• the capacity of the screen is diminished but its life is extended.
• several cells of a screen can be repaired before its capacity drops far enough to require replacement.
• bonding the screen to the support panel further restricts relative movement of the layers and the wires in each mesh layer, thus compounding the problem of blinding .
• the present invention provides a method for making a screen assembly for a vibratory separator, the method comprising the steps of placing at least two layers of screening material one on top of the other, introducing glue to one of the at least two layers of screening material for adhering at least portions of them together, said glue introduced to one of the at least two layers of screening material from a roller with a patterned surface thereon such that the amount of glue is introduced to the at least two layers of screening material in a pattern substantially corresponding to said patterned surface of the roller.
• the invention also relates to a screen made by the method and to a system for making a screen in accordance with the method.
• the invention also relates to a screen made by the above method and to a system for making a screen in accordance with the method.
• Figure 1 is a side schematic view of a first embodiment of an apparatus for making screens in accordance with the present invention, indicating steps in a method of making screens in accordance the present invention ;
• FIG 3 is an enlarged side view of an alternative roller apparatus for use in the apparatus as shown in Figures 1 or 2 ;
• Figure 4A is an enlarged front view of part of a pattern roller for apparatus as in Figure 1 ;
• Figure 5B is a side view of the roller of Figure 5A;
• Figure 6A is an end view of a second embodiment of pattern roller ;
• Figure 6B is a side view of the roller of Figure 6A;
• Figures 7 and 8 are side views of alternative pattern rollers ;
• Figure 9 is a top view of a screen in accordance with the present invention.
• Figure 10 is a top view of a screen in accordance with the present invention with parts cut-away; and
• FIG. 1 shows a system 100 according to the present invention for making a screen 2 according to the present invention by a method according to the present invention .
• the system 100 produces a screen 2 which includes a lower coarse mesh or screen 4 , an intermediate mesh or screen 6 , and a top mesh or screen 8. Any one of these meshes (or screens) 4, 6, 8 may be omitted. Alternatively one or more additional mesh layers may be added.
• the coarse mesh 4 is initially wound on a roller 11 from which it is unwound and passes over a rotating roller 13. From the roller 13 the coarse mesh moves to a position beneath a gluing station 20 where glue in a pattern is applied on the coarse mesh 4.
• the coarse mesh is 19 mesh made of wire with a diameter of about 0.32cm (0.126 inches) .
• a pattern roller 30 applies a layer of glue in a desired pattern onto the coarse mesh 4.
• Glue 40 from a reservoir/manifold 50 flows to a space forming a "pond" of glue between a first roller 15 and a transfer roller 17. Either or both of these rollers may be a heated roller.
• hot air from an optional heater H may be blown at the roller (s) and/or at the "pond", and/or it may heat the glue in the reservoir/manifold 50.
• the transfer roller 17 rotates counter-clockwise as viewed in Figure 1 and the first roller 15 rotates clockwise; thus a film of glue is deposited on the outer surface of the transfer roller 17 which film, in turn, contacts parts of a pattern in or on an outer surface of the pattern roller 30 which rotates clockwise as viewed in Figure 1.
• the film on the pattern parts of the pattern roller 30 is applied in the pattern onto the coarse mesh 4 moving beneath the pattern roller 30.
• glue is applied on top of a combination of two , three , or more meshes prior to entering between the rollers 61 (rather than on top of the coarse mesh when it comes off the roll 11) .
• the glue is applied only to the mesh from either the roll 9 or the roll 7.
• the coarse mesh 4 with glue thereon in a desired pattern determined by the pattern on the pattern roller 30 advances to a pressing station 60.
• the intermediate mesh 6 is fed between rollers 61 and 62 of the pressing station 60 from a roll 7 as is the top mesh 8 from a roll 9.
• a fine mesh is unwound from the roll 111 and fine, finer, or coarse mesh or meshes are unwound from the rolls 107 and 109.
• the glue 40, 140 may be any suitable glue, including, but not limited to, polyethylene glues and hot melt glues at a suitable temperature for flowing to and from a reservoir/manifold and onto a mesh, for example, but not limited to at about 121°C (250°F) , between 121°C (250°F) and 204°C (400°F) , or at other suitable temperatures for the particular glue being used.
• Figures 5A and 5B show a pattern roller 80 useful as the pattern roller 30 of the system 100 in Figure 1. Raised portions 81 on an exterior surface 82 of the pattern roller 80 form the desired pattern for applying glue to a mesh.
• the roller 80 is solid with end shafts 83 for mounting to suitable supports for rotation.
• Figures 7 and 8 present pattern rollers with patterns or raised portions different from that of the patterns of the rollers of Figures 5B and 6B .
• the rollers of Figures 7 and 8 may have any of the options of the rollers of Figures 5B and 6B (including, but not limited to end shafts 83 and bore 84 , or a perforated tube structure) .
• a roller 85 in Figure 7 has raised lines 86 that define a pattern across the roller.
• a roller 87 in Figure 8 has raised portions 88 and 89 that define a pattern across the roller.
• Figure 9 shows a screen 90 produced with a system like the system 100 of Figure 1, using a roller like the roller 85 of Figure 7.
• Figure 10 shows a screen 92 with a glue layer 93 according to the present invention produced with a system like the system 100 of Figure 1 using a roller like the roller 87 of Figure 8.
• the screen 92 is like the screens disclosed in U.S. Patent 4,575,421 (incorporated fully herein for all purposes), but made with a system according to the present invention and by a method according to the present invention.
• the screen 92 has three layers of mesh or screening material 56, 57 and 58 and a lower perforated plate 54. Any of the layers of mesh may be omitted and the glue 93 may be applied on top of any of the layers .
• Figure 4A shows an enlargement of part of a pattern roller 96 which is similar to the roller 80 of Figure 5B, but which has valleys, recesses or grooves 97 in raised portions 98 of the roller. Glue is received within the grooves 97 so that a relatively higher or thicker level or bead of glue is applied to a mesh by the roller as compared to the layer or film of glue applied by a roller like the roller 80. Any raised portion of any roller disclosed herein may include such a valley recess, or groove to increase the amount of glue applied on a mesh.
• FIG. 4B shows a cross-section of one glue bead's B profile applied to a screen S with a pattern roller having grooves in raised portions of the pattern.
• the distance "a” is, in this embodiment, about 0.16cm (one-sixteenth of an inch) .
• the distance "b" is as thin as possible.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Laminated Bodies (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=23805804

Family Applications (1)

Country Status (5)

Cited By (9)

Citations (4)

• 2000
  • 2000-12-04 WO PCT/GB2000/004615 patent/WO2001039861A1/en not_active Application Discontinuation
  • 2000-12-04 EP EP00981470A patent/EP1242158A1/en not_active Withdrawn
  • 2000-12-04 CA CA002382705A patent/CA2382705A1/en not_active Abandoned
  • 2000-12-04 AU AU18707/01A patent/AU1870701A/en not_active Abandoned
• 2002
  • 2002-05-03 NO NO20022119A patent/NO20022119L/no not_active Application Discontinuation

Patent Citations (4)

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