CA2689771C

CA2689771C - Processing equipment including improved screen hole opening constructions

Info

Publication number: CA2689771C
Application number: CA2689771A
Authority: CA
Inventors: Dallas Chapple; Ermanno Simonutti
Original assignee: Esco Corp
Current assignee: Esco Group LLC
Priority date: 2009-01-06
Filing date: 2010-01-06
Publication date: 2017-06-13
Anticipated expiration: 2030-01-06
Also published as: CA2965065C; CA2965065A1; CA2689771A1

Abstract

Rotary breakers and other screening equipment include process holes formed by a matrix of bars. The spacing between at least the longitudinal (or axial) bars making up the process holes may be varied or controlled. For example, the spacing between the longitudinal bars can be selected to improve the flow of desired product material through the process holes. The process holes may have an angled trailing edge side with respect to the material flow direction to better capture the product material and to reduce wear. The longitudinal bars also may have a modular construction to allow for relatively easy removal, repair, replacement, and/or repositioning.

Description

PROCESSING EQUIPMENT INCLUDING
IMPROVED SCREEN HOLE OPENING CONSTRUCTIONS
FIELD OF THE INVENTION

The present invention relates to processing equipment used, for example, in the mining industry to separate oil sands from rocks or other debris that is present after initial surface mining processes. Such processing equipment may include screens for processing the oil sands or other raw materials, such as screens provided in rotary breaker machinery, vibratory screening systems, and stationary screening systems.

BACKGROUND
Rotary breakers are rotary drum structures that break up and separate materials by repeatedly lifting a crude feed material within the drum and allowing it to drop against strong screens that make up the interior surface of the drum. This lifting and dropping action breaks up the feed material (e.g., separates oil sands from any rocks or other elements on which it may be caked, breaks up large pieces of the relatively soft oil sands, etc.). The smaller, broken up particles resulting from this process pass through the screen interior to a collection device provided below. The larger rocks or other harder debris, now cleaned of the desired oil sand material, will not pass through the screens and will be discharged out the other end of the drum (the drum may be oriented on a non-horizontal angle to facilitate feeding of the material through the drum). Similarly, other screening equipment, such as vibratory screening systems and stationary screening systems, may be used to separate oil sands from large rocks or other debris.

In mining processes, several tons of crude rock, sand, and dirt feed material move through rotary breaker screens or other screens of the types described above.
This feed material is extremely heavy and abrasive, which can quickly wear out the materials of the screens as the feed material crashes into and tends to slide along the surface of the screens. While the screen surfaces can be treated with a wear resistant material to increase their useful life, this greatly increases the costs associated with manufacturing and/or maintaining the screens. Moreover, the production downtime involved in repairing or replacing all or a portion of a rotary breaker screen or other screening equipment results in significant production losses of time, manpower, and money.

As noted above, because of the large volumes of material treated, the feed material tends to somewhat "slide" along the top surfaces of the screen (e.g., it is lifted upward and tends to somewhat slide back down under the force of gravity or slides along the screen under gravity and/or vibrational forces). In such an action, it can be somewhat difficult for the desired product material to find its way through the screen holes for collection and further processing. As a result, much useful product material (e.g., oil sands) passes completely through the rotary dnzm or other screening system without the desired product falling through the holes (particularly if the input feed rate and/or drum rotational speed rate are not carefully controlled by the operator based on the product recovery). This results in either excessive waste or prolonged processing times (e.g., if much of the discharged "waste" material from the rotary breaker or other screening system must be recycled or reprocessed in the rotary breaker or in another rotary breaker or other machinery).

Accordingly, there is room in the art for improvements in the structure and construction of screens for rotary breakers and other types of screening machinery.

SUMMARY OF THE INVENTION

The following presents a general summary of aspects of the present invention in order to provide a basic understanding of the invention and various example features of it. This summary is not intended to limit the scope of the invention in any way, but it simply provides a general overview and context for the more detailed description that follows.
Aspects of this invention relate to rotary breaker machinery or other screening equipment in which a matrix of bars defines the process holes and the screen. The bars, which may be oriented in the drum's axial (or longitudinal) direction and the drum's circumferential or transverse direction, may be attached to the border or frame of the screen by welding, mechanical connectors, etc.

2 Additional aspects of this invention relate to rotary breaker machinery or other screening equipment in which the spacing between at least some of the bars (e.g., the longitudinal (or axial) bars in a rotary breaker drum) making up the process holes of the screen may be varied or controlled. For example, the spacings between the longitudinal bars can be set to improve the flow of desired product material through the process holes.
The spacing between the circumferential or transverse bars may be fixed, and it may be selected to set a maximum size of the material that will pass through the process holes.
Additional aspects of this invention relate to providing the process holes in a rotary breaker or other screening equipment with an angled side, for example, at the trailing longitudinal side edge of the hole. By providing an angled, trailing, longitudinal edge, the angle at which the feed material contacts the longitudinal bars can be reduced or minimized, which helps reduce wear of the bars (e.g., by reducing the raw material's sliding action). Additionally, by angling the process hole side, for example, at the trailing longitudinal side edge of the hole, the angle may be selected to better match an expected angle of the flow of the material during the rotary breaking process (e.g., the angle at which the feed material falls downward after being lifted). This feature can improve the flow of desired product material through the process holes and thereby increase the amount of captured product obtained in the process. As used in this context in this specification, unless otherwise noted, the "trailing edge" is the rearmost edge or structure that defines a screen hole with respect to a material flow direction.
Conversely, the "leading edge," as used in this context in this specification unless otherwise noted, is the forwardmost edge or structure that defines a screen hole with respect to a material flow direction.

As some more specific examples, rotary breaker drums according to this aspect of the invention include one or more sections of a screen having a frame member forming a portion of an arc of a circle or a portion of a polygonal cross section of the overall drum.
This frame member includes a plurality of openings defined therein, wherein at least a first opening of the plurality of openings is defmed by: (a) a first circumferential side, (b) a second circumferential side opposite the first circumferential side, (c) a first longitudinal side extending between the first and second circumferential sides to define a

3 leading edge of the first opening with respect to a rotational direction of the rotary breaker drum, and (d) a second longitudinal side extending between the first and second circumferential sides and opposite the first longitudinal side, wherein the second longitudinal side defines a trailing edge of the first opening with respect to the rotational direction of the rotary breaker drum, and wherein an angle between the second longitudinal side and a top surface of the first circumferential side of the first opening is in a range of 30 to less than 90 .

Still additional aspects of this invention relate to providing the process holes in a rotary breaker or other screening system as formed from circumferential or transverse sides and longitudinal sides, wherein at least some of the longitudinal sides have a greater height than the circumferential or transverse sides (e.g., the longitudinal sides extend inward (or upward in a vibratory system) toward the material flow into the drum interior (for a rotary breaker drum) a greater distance than the circumferential or transverse sides).
These features also help reduce wear of the circumferential or transverse sides, help capture the falling desired product within the holes, and help improve desired product recovery.

As some more specific examples, rotary breaker drums in accordance with this aspect of the invention may include sections of a screen having a frame member forming a portion of an arc of a circle or a portion of a polygonal cross section of the drum, wherein the frame member includes a plurality of openings defined therein, and wherein the frame member includes a concave interior side and a convex exterior side. At least a fust opening of the plurality of openings in this screen section is defined by: (a) a first circumferential side, (b) a second circumferential side opposite the first circumferential side, (c) a first longitudinal side extending between the first and second circumferential sides to define a leading edge of the first opening with respect to a rotational direction of the rotary breaker drum, and (d) a second longitudinal side extending between the first and second circumferential sides and opposite the first longitudinal side, wherein the second longitudinal side defines a trailing edge of the first opening with respect to the rotational direction of the rotary breaker drum, and wherein the second longitudinal side

4 extends toward the concave interior side to a greater height than the first or second circumferential sides.

Additional aspects of this invention relate to providing the process holes in a rotary breaker or other screening equipment as formed from circumferential bars and longitudinal bars, wherein at least some of the longitudinal bars are made from straight, uncurved and continuous metal bars. The circumferential bars may be straight or curved (e.g., depending on whether the rotary breaker has a polygonal or round cross section, or depending on whether the bars are used in other screening equipment). The longitudinal bars may be made in a modular construction that facilitates stockpiling of replacement bars. These features ease the production of the screens, ease treatment of the hole interiors to provide a wear resistant overlay (such as hardfacing material), and ease further handling of the screens when making repairs or when replacing the longitudinal bars.

Another aspect of this invention relates to providing the process holes in a rotary breaker or other screening equipment as formed from circumferential or transverse bars and longitudinal bars, wherein only the top and/or interior trailing edge of the longitudinal bars (with respect to the direction of drum rotation) include a wear resistant material thereon, such as a hardfacing material (and the circumferential or transverse bars optionally have no wear resistant material or less wear resistant material).
In other example aspects of this invention, other selected portions of the circumferential or transverse bars and/or the longitudinal bars may include wear resistant material thereon, such as the top corner surfaces of the longitudinal bars (e.g., a portion of the top surface and the interior side surface of a screen hole), the top surfaces of any of these bars, the leading edge surfaces of the longitudinal bars, etc. In other words, wear resistant material may be selectively provided at any desired surfaces of the various bars, e.g., based on typical wear patterns, etc. These features can reduce the amount of and/or lower the cost of providing wear resistant materials on the surface of the breaker drum or other screening equipment, reduce the time involved in applying the wear resistant material, and/or ease the procedure by which the wear resistant material is applied.

Still additional aspects of this invention relate to repairing sections of screens of rotary breaker drums or other screening equipment having a plurality of openings defined therein, wherein a first opening of the plurality of openings is defmed in part by a first longitudinal bar extending across the section of the screen. Such methods may include, for example, disengaging the first longitudinal bar from the section of the screen; and engaging a second longitudinal bar with the section of the screen such that the second longitudinal bar replaces the first longitudinal bar and partially defines the first opening in the repaired section of the screen. As another example, the first opening may be partially defined by a first longitudinal bar extending across the section of the screen and a second longitudinal bar extending across the section of the screen, and the repair method may include: (a) disengaging the first longitudinal bar from the section of the screen; (b) disengaging the second longitudinal bar from the section of the screen; (c) engaging a third longitudinal bar with the section of the screen such that the third longitudinal bar replaces the first longitudinal bar; and (d) engaging a fourth longitudinal bar with the section of the screen such that the fourth longitudinal bar replaces the second longitudinal bar, wherein the third and fourth longitudinal bars partially defme the first opening in the repaired section of the screen.

Other aspects, advantages, and features of the invention will be described in more detail below and will be recognizable from the following detailed description of example structures in accordance with this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limited in the accompanying figures, in which like reference numerals indicate the same or similar elements throughout, and in which:

Fig. 1 illustrates an example oil sands production procedure in which rotary breaker constructions in accordance with examples of =this invention may be utilized;

Figs. 2A through 2C illustrate various examples of features of conventional rotary breaker structures;

Figs. 3A through 3E illustrate various example features of and example steps in production of rotary breaker sections and structures in accordance with this invention;
Figs. 4A and 4B illustrate examples of differences in construction and material flow in holes provided in conventional rotary breaker drums (Fig. 4A) and holes provided in rotary breaker drums in accordance with examples of this invention (Fig. 4B);

Figs. 5A and 5B illustrate examples of features of screen sections for polygonal rotary breaker drums and other processing systems utilizing flat screen sections in accordance with this invention; and Figs. 6A and 6B illustrate example features of vibrational and/or stationary screening systems in accordance with this invention.

The reader is advised that the various parts shown in these drawings are not necessarily drawn to scale.

DETAILED DESCRIPTION

The following description and the accompanying figures disclose example features of rotary breaker machinery or other screening equipment and the process holes formed therein in accordance with the present invention.

Fig. 1 illustrates an example surface mining and oil sands processing procedure 100 in which rotary breaker or other screening machinery in accordance with examples of this invention may be utilized. The rotary breaker drums illustrated in the Fig. 1 process may be replaced with other screening equipment, such as a vibratory screening system (see, e.g., Figs. 6A and 6B). Rotary breaker and other screening machinery in accordance with examples of this invention also may be utilized in other processes without departing from this invention, such as coal processing, alumina processing, and the like.
However, the use of the inventive concepts is especially useful in regard to processing oil sands in rotary breaker drums on account of the high abrasion encountered in these mines and the associated high rate of repair and replacement that is then needed.

As a first step in this overall process, mining shovels 102 dig oil sand ore raw material (or other raw material) in a surface mining process and load it into large trucks 104. In addition to the desired oil sands, this raw material may include snow, ice, rocks, and other large hard pieces of material to which the oil sands may be adhered. The trucks 104 transport the raw material to a crushing station 106 in which the raw material is broken down in size, e.g., to 45 cm pieces or less. Any desired type(s) of crushing equipment can be used without departing from this invention, including crushing equipment that is conventionally known and used in the mining field. Once crushed, if necessary, the resultant material can be transferred to a storage silo 108 to await further processing.

During storage, or at another appropriate time in the processing procedure, the raw material may be mixed with water (e. g. , optionally warmed water) and then fed (e.g., via a pipeline, conveyor, or other suitable transport means 110) to extraction facilities. In the example procedure shown in Fig. 1, a rotary breaker 112 is the first station of the extraction facilities. In the rotary breaker 112, the rotating drum 112 mixes the oil sand and water (and other mined materials) while further reducing the size of the raw material (e.g., to about 5 cm). As will be explained in more detail below, in the rotary breaker 112, the oil sands are separated from any larger rocks or other material. More specifically, rotation of the rotary breaker drum 112 (typically from 5-20 rpm or even between 10-15 rpm) picks up the raw material and drops it onto the interior surface of the drum, which is formed as a screen. The smaller oil sands product falls through the screen for further processing, and the larger rocks and undesired materials that do not fall through the screen are discharged out the free end 1 12b of the breaker 112 (e.g., as waste, for further processing, etc.). Additionally or alternatively, other screening equipment may be used in addition to or in place of the rotary breaker 112, such as vibrational screening systems, stationary screening systems, etc.

From the rotary breaker 112 and/or other screening equipment, the product material (e.g., collected in a hopper located under the rotary breaker screen or other equipment) is transported via pipeline 114 (or other transport means) to a primary separator system 116 (such as a rotary separator). Optionally, the pipeline 114 may include features, such as static mixers or the like, to further mix the oil sand and water material flowing therethrough. From the primary separation system 116, the sand and water tailings are pumped to a settling basin 118 from which the water may be recycled. The dirty bitumen water and sand material are sent to one or more washing stations 120 or other treatment stations. For example, the dirty bitumen water and sand material mixture may be sent to a froth settler and given time to settle. As another example, the bitumen material may be washed with a hydrocarbon solvent. Any desired type of processing may take place at stations 120, including conventional cleaning processes that are known and used in the art.

After cleaning (and optional storage), clean, dry, diluted bitumen may be transported (e.g., via pipeline 122) for further processing. As some more specific examples, the heavy bitumens may be formed into synthetic crude oils, e.g., by breaking the bitumen molecules into smaller molecules and adding hydrogen in the presence of a catalyst, heat and pressure. This may take place at processing system or plant 124. Sulfur and nitrogen also may be removed from the crude bitumens. Products from this processing system or plant 124 may be sold on the general market 126 or may be further processed at a refinery 128, e.g., to gasoline 130, diesel fuel, other fuels or other desired refined chemical products.

As noted above, Fig. 1 simply constitutes one example process in which rotary breaker equipment in accordance with this invention may be utilized. Many variations in the overall process, system, materials, final products, and the like may be used without affecting aspects of this invention.

Figs. 2A through 2C illustrate various features of conventional rotary breaker systems.
Fig. 2A generally illustrates one example rotary breaker installation. While rotary breakers in accordance with the present invention may be constructed in any desired size, conventional rotary breakers may have interior diameters D from 6-20 feet and axial (or longitudinal) lengths L of at least 15 feet, and in many instances at least 20 feet, 30 feet, 40 feet, or even 60 feet or more. The feed material goes into one end 200a of the rotary breaker 200, and waste material is eventually discharged out the opposite end 200b of the breaker 200. Any desired rotary mechanism 202 may be used to rotate the large dnim 200. A collection hopper or collection area 204 may be provided to capture the material that falls through the openings of the screens.

Fig. 2B is a cutaway view of a conventional rotary breaker 200 that better illustrates the interior area of a rotary breaker 200. As shown, a typical rotary breaker drum 200 may be made from multiple independent and curved sections 210. Each section, for example, may extend 45 around the circumference of the drum 200 such that eight sections complete the entire circular cross section of the drum 200. Any desired number of circumferential sections may be provided. Additionally, if desired, two or more circumferential sections may be axially aligned to provide a longer drum structure. In the example illustrated in Fig. 2B, eight circumferential sections are axially aligned to provide the overall desired longitudinal length L of the drum. Rotary breaker structures 112 in accordance with examples of this invention may include this same general modular construction, e.g., with multiple curved sections extending around the drum's circumference and/or with multiple sections extending along the drum's axial or longitudinal length L.

As shown in Fig. 2B, the interior of the rotary breaker 200 may include various lifters 212 or other structures to help pick up the feed material (e.g., to be dropped as the drum 200 rotates) or to otherwise reposition the feed material (e.g., move the material back toward the front of the drum 200, move the material forward toward the outlet end of the drum 200, etc.). This dropping action helps break up the relatively soft oil sands feed material and/or loosen the oil sands (or other desired products) from rocks or other hard materials to which it is adhered. Rotary breaker structures 112 in accordance with examples of this invention may include these same general types of lifters or other feed material repositioning elements.

As mentioned above, rotary breakers include holes through which some of the material falls as the breaker rotates and breaks up the feed material. Fig. 2C
illustrates through holes 220 of a conventional rotary breaker screen. As shown, the holes 220 generally are cut or punched through the material making up a curved section panel 210.
Notably, the entire interior surface of the curved section panel 210 is treated with a wear resistant material 222, such as a plasma transferred arc ("PTA") cladding material as is known and used in the art (e.g., a tungsten carbide overlay or a cast chrome white iron wear bar material). Because the holes 220 are simply cut into or punched through the smooth surface of the screen segment (i. e. , in this example, both the longitudinal portions 224 and the circumferential portions 226 defining the through holes 220 extend into the drum interior the same distance) a relatively smooth interior drum surface is provided. As also shown in Fig. 2C, the section panel 210 may include countersunk bolt areas 228, e.g., that allow the panel section to be attached to other sections 210, to an exterior frame, to other equipment, etc. Fig. 2C further illustrates that some areas of the screen structure may not include through holes 220, e.g., to protect structures that lie beneath that portion of the screen (such as drum frames 250, etc.). Note, also, the areas of the screens without holes shown in Fig. 2B.

Typically, rotary breaker drum sections 210 of this type are initially made flat (with the cut or punched through holes to define the openings 220), and the section 210 is then processed into the curved structure shown in Figs. 2B and 2C. This curving process takes a considerable amount of time and expense, and it places a substantial amount of stress on the various parts of the drum section strncture 210.

Figs. 3A through 3E illustrate examples of rotary breaker drum sections 300 and methods of making them in accordance with examples of this invention. These drum sections 300 differ from the sections 210 described above in conjunction with Figs. 2A
through 2C, although drum sections 300 may still share a similar modular construction in which plural dnxm sections 300 form the circumferential shape of the overall breaker and/or plural drum sections 300 form the longitudinal length of the overall breaker.

As illustrated in Fig. 3A, the drum section 300 begins with an exterior frame member 302, which may be made from one or more parts (e.g., parts 302a through 302d, with one individual part (or more) per each external frame side). When made from multiple parts, the various frame parts 302a through 302d may be joined together in any desired manner, such as via welding, via mechanical connectors (such as bolts), etc. The frame member 302 defines a large central opening 304. At least some of the frame parts 302a through 302d may include countersunk portions 306 into which bolts or other mounting mechanisms or connection structures may be received, e.g., for bolting the various drum sections 300 together, for mounting the drum section 300 to another part of the rotary breaker (such as an exterior skeleton or frame), etc. If desired, the frame member 302 may include other structures, such as holes, ledges, or receptacles into or onto which the various bar members may be mounted, as will be described in more detail below.
Optionally, if desired, the frame members 302a through 302d may include lifters 212 of the types described above or other feed material repositioning elements. As another option, at least some lifters 212 may be positioned on the upstream side of the countersunk portions 306 (with respect to the direction of rotation) to help prevent the heavy feed material from entering or damaging the countersunk portions 306 or the structures contained therein.

Because the example frame member 302 is made from multiple parts 302a through 302d, these parts 302a through 302d may be made in a curved manner with relative ease, as compared to creating a curve in the large, heavy plate section structures 210 shown in Figs. 2A through 2C. The frame member 302 may be made in its curved shape (e.g., to constitute about a 45 arc of the circumference of the drum) either before or after the frame structure 302 is made, and the various parts 302a through 302d may be curved individually or simultaneously without departing from this invention. Other sized frames 302 also may be provided without departing from this invention, such as frames extending 1/2, 1/4, 1/6, 1/10, 1/12, or 1/16 of the circumference of the circular cross section.

Once the frame 302 is made, plural transverse or circumferential (which in this example are curved) bars 308 may be added, as shown in Fig. 3B, to produce slatted frame 310.
The circumferential bars 308 will partially define the size of the holes through that section 300 of the overall rotary breaker, depending on the spacing between the bars 308.
More specifically, the drum section 300 manufacturer or on-site construction team can determine the axial spacing between the various bars 308. As illustrated in Fig. 3B, in this illustrated example slatted frame structure 310, the circumferential bars 308 extend from frame part 302a to frame part 302d and define about one-eighth of the circumference (45 ) of the overall rotary breaker. While the circumferential bars 308 may extend in any desired direction across the opening 304, in this illustrated example, the circumferential bars 308 extend substantially perpendicular to the frames 302a and 302d and substantially parallel to frames 302b and 302c and curve around to create the drum perimeter (or a portion thereof). The circumferential bars 308 of this example slatted frame structure 310 also extend in a direction transverse to the axial direction of the overall rotary breaker drum (i.e., along a perpendicular cross section of the rotary breaker drum, once the drum is constructed from plural sections, such as section 300).
The spacings between bars 308 may be constant or varied over the longitudinal length direction (direction "L") of the slatted frame 310. Also, the bar 308 spacings at one end (e.g., at frame 302a) may differ from the spacings at the other end (e.g., at frame 302d).
The bar 308 spacings also may differ along the longitudinal length of a drum.

The circumferential bars 308 may be engaged with the frame parts (e.g., 302a, 302d) in any desired manner without departing from this invention. As some more specific examples, the circumferential bars 308 may be welded to the frames 302a and 302d, bolted to the frames 302a and 302d, both welded and bolted, etc. As another example, if desired, one or both of the frames 302a and 302d may be fabricated with or modified to include a support structure (such as a ledge 312 along the outside of the frame's length that extends a short distance into the opening 304) to help facilitate consistent positioning of the circumferential bars 308. Optionally, this ledge 312 may be removed before the final drum is constructed from multiple sections 300. Alternatively, particularly if the circumferential bars 308 are engaged with the frame 302 when the frame 302 remains flat, the ledge 312 may be omitted. Thus, the circumferential bars 308 may be made flat and later curved, either before or after they are engaged with the frame 302.

As another alternative, if desired, the frame member 302 may be made as a single piece, optionally with the circumferential bars 308 also integrally formed therewith (i.e., the slatted frame 310 of Fig. 3B also may be made as a single, unitary piece). The frames 302 and/or 310 may be made flat and later curved, e.g., in manners that are known in the steel and metal working arts, or they may be constructed from their constituent parts after the desired curves have been formed.

Fig. 3C illustrates an example longitudinal bar 320 that may be included in the frame member 302 (and/or slatted frame member 310) in rotary breaker constructions in accordance with examples of this invention. The longitudinal bars 320 include an upper or interior portion 322 and a lower portion 324 with spaced apart openings 326 into which the circumferential bars 308 fit. The upper portion 322 and the lower portion 324 of the longitudinal bars 320, along with the circumferential bars 308, define the openings in the rotary breaker drum through which the desired product material falls.
Fig. 3D
illustrates a partial view of the rotary breaker drum section 300 of this example of the invention, including the frame 302, the circumferential bars 308, and the longitudinal bars 320. Therefore, in accordance with this example structure 300 according to the invention, the process holes (e.g., holes 350) in the rotary breaker drum) are defined by the matrix of bars 308 and 320.

Figs. 3C through 3E further illustrate that the top surface 328 and the trailing edge surface 330 of the breaker drum through holes 350 (with respect to the direction of rotation, represented by arrow "A") of the longitudinal bars 320 further include a wear resistant material 332 thereon. While any desired wear resistant material 332 may be used without departing from this invention, some more specific examples of such materials are plasma transferred arc ("PTA") cladding materials as are known and used in the art, such as tungsten carbide or cast chrome white iron wear bar materials.

The longitudinal bars 320 may be engaged with the frame parts (e.g., 302b, 302c) and/or the circumferential bars 308 in any desired manner without departing from this invention.
As some more specific examples, the longitudinal bars 320 may be welded to the frames 302b and 302c, bolted to the frames 302b and 302c, both welded and bolted to the frames 302b and 302c, welded to some or all of the circumferential bars 308, bolted to some or all of the circumferential bars 308, both welded and bolted to some or all of the circumferential bars 308, etc. The spaced apart openings 326 of the longitudinal bars 320 are positioned to overlay the circumferential bars 308, as shown in Fig. 3D, and thus the circumferential bars 308 can support the longitudinal bars 320 during the process in which the longitudinal bars 320 are engaged with the frame 302. Optionally, other fabrication supports (e.g., like ledge 312) can be provided, if necessary or desired.

Like the circumferential bars 308, the longitudinal bars 320 will partially define the size of the holes 350 through that section 300 of the overall rotary breaker, depending on the spacings between the bars 320. More specifically, the manufacturer or on-site construction team can determine the circumferential spacings between the various longitudinal bars 320. As illustrated in Fig. 3D, in this illustrated example frame structure 302, the longitudinal bars 320 extend from frame part 302b to frame part 302c and define at least a portion of the overall longitudinal (or axial) length of the overall rotary breaker. While the longitudinal bars 320 may extend in any desired direction across the opening 304 and across the circumferential bars 308 (e.g., depending on the angles and orientations of the spaced apart openings 326), in this illustrated example, the longitudinal bars 320 take the shortest path from one side 302b to the other side 302c (i. e. , the longitudinal bars 320 extend perpendicular to the side frames 302b and 302c and parallel to frames 302a and 302d). The longitudinal bars 320 of this example structure 302 also extend in a direction parallel to the axial direction of the overall rotary breaker drum (i. e. , transverse to a perpendicular cross section of the rotary breaker drum, once the drum is constructed from plural sections, such as section 300). The spacings between bars 320 and/or the heights of the bars 320 (e.g., the extent to which the tops of bars 320 extend into the drum interior) may be constant or varied over the length of the arc making circumference (direction "A") of the frame 302. Also, the bar 320 spacings and/or bar 320 heights at one end (e.g., at frame 302b) may differ from the spacings and/or heights at the other end (e.g., at frame 302c). The various bars 308 and 320 may be oriented in any desired directions with respect to the frame 302. For example, in some instances, the bars 308 and 320 may be angled with respect to the frame 302 in order to better match the entry direction of the holes 350 with the expected flow direction of the material as it moves within the breaker. The bar 320 spacings and/or heights also may be constant or varied over the longitudinal length of a drum.

If desired, the interior structure of the rotary breaker section 300 may be equipped with one or more lifters 212 and/or other material moving structures, like those described above in conjunction with Fig. 2B. Also, if desired, some of the holes 350 defined between the circumferential bars 308 and the longitudinal bars 320 may be filled or plugged, e.g., like plugged holes 352 in Fig. 3D, to protect other structural components of the drum (or other equipment) that reside outside of the holes 350, such as support beams 250 shown in Fig. 2A. Any desired type of plugging material may be used, such as steel (optionally treated with wear resistant materials, like those described above) welded to the bars 308 and/or 320. The plugging material, when present, may extend to the internal height of the circumferential bars 308 (as shown in Fig. 3D), or to any other desired level.
In the description above, the longitudinal bars 320 are modified to include the spaced apart openings 326. This is just one example constnaction. If desired, the spaced apart openings 326 could be provided on the circumferential bars 308. As another possible option, if desired, both the longitudinal bars 320 and the circumferential bars 308 may include portions of the openings 326 (e.g., portions that mate together).
Combinations of these constructions may be used in an individual screen and/or in an overall drum structure including multiple screens, if desired.

Fig. 4A illustrates the structure of an individual hole 220 in a conventional rotary breaker (with one wall of the hole 220 cut away to illustrate the interior of the hole 220). As shown, the interior drum surface 402 (defined by the top interior surface of the material making up the drum and its through holes 220) is relatively smooth because the structures 404, 406, and 408 defining the holes 220 extend to the same level within the interior of the drum. The holes 220 are arranged perpendicular to the interior surface of the drum, without reference to the path that the material flows in reaching the holes 220. In such a stnicture, as the drum rotates and the material within is lifted up (e.g., by lifters as described above), the material 420 will tend to fall downward and impact the top interior surface 402. While some material 420a that hits the trailing edge of the longitudinal structure defining the hole 220 (with respect to the drum's direction of rotation) will fall within the hole 220, much of the falling material 420b will miss the hole 220 and will essentially slide along the interior surface 402 of the drum. In addition to limiting and/or reducing the recovery of desired material, this sliding action greatly wears the interior surface 402 of the drum (even if the entire interior drum surface 402 is treated with a wear resistant coating).

As shown in Figs. 3C through 3E and 4B, however, the hole openings 350 in accordance with at least some examples of this invention differ significantly from the conventional hole openings 220 described above. First, in accordance with at least some examples of this invention, the spaced apart openings 326 in the longitudinal bars 320 are shaped and arranged such that the longitudinal bars 320 extend inward (toward the drum interior) at an angle as compared to the surface 308a defined by the top surface of the circumferential bar 308 and/or as compared to a radial direction extending out from the central axis of the rotary breaker drum. The angle a defined between the interior side surface 330 of the trailing edge of the longitudinal bar 320 and the corresponding top surface 308a of the circumferential bar 308 defining the hole 350 (or a tangent to the top surface 308a at the location of the trailing edge of the longitudinal bar 320) may be in the range of 30-90 , and in some examples, in the range of 30 to less than 90 , 30-80 , 30-70 , 30-60 , or even 40-50 . In some example structures, this angle a will be about 45 .
The angle P between the interior side surface 330 of the trailing edge of the longitudinal bar 320 and the radial direction of the drum may be in the range of 0-60 , and in some examples, in the range of greater than 0 to 60 , 10-60 , 20-60 , 30-60 , or even 40-50 .
In some example structures, this angle 0 will be about 45 .

Another notable difference between the hole openings 350 in accordance with this example of the invention and those shown in Fig. 4A (and Fig. 2C) relates to the uneven interior drum surface. More specifically, as shown in Figs. 3D, 3E, and 4B, in accordance with at least some examples of this invention, the spaced apart openings 326 in the longitudinal bars 320 are shaped and arranged such that the top surface 328 of the longitudinal bars 320 extends into the interior of the rotary breaker drum farther than the top surface 308a of the circumferential bars 308. The top surface 328 of the longitudinal bars 320 may extend above the top surface 308a of the circumferential bars 308 any desired amount. As some more specific examples, the overall height differential AH (i.e., H2 - HI, including any present wear resistant material) may be at least 0.25 inches, at least 0.5 inches, at least 1 inch, at least 2 inches, at least 3 inches, at least 4 inches, or even more. As additional examples, if desired, the overall height H2 (including any present wear resistant material) may be made to be at least 1.2H1 (including any present wear resistant material), and in some examples, at least 1.5H1, at least 1.75H1, at least 2H1, at least 2.51-11, or even at least 3H1. The measured heights Hl and H2, as well as the height differential AH, also may be measured without including any wear resistant materials (and still fall within the parameters set forth above).

The angles a and R and the height differential AH can be selected so as to better match the expected angle of flow of material 420 within the rotary breaker drum as it falls (e.g., after being elevated by a lifter structure, such as those shown in Fig. 2B) and to better receive the falling material. The angle of material fall may depend on various factors, such as the thickness or consistency of the material in the drum, the rotational speed of the drum, the throughput or amount of material contained in the drum, etc.
With the taller longitudinal sides of the hole 350 (as compared to the circumferential sides) and the angled entry opening to the hole 350, as shown in Fig. 4B, the elevated longitudinal sides of the trailing edge of the hole openings 350 more effectively capture the falling material 420 into the hole opening 350 (e.g., the material 420 is partially within the hole 350 when it contacts the trailing edge side 330). Thus, the holes 350 more effectively capture the desired product material 420a within the hole opening 350, particularly as compared to having the material 420 slide along the relatively smooth interior surface of the drum as described above in conjunction with Fig. 4A. This reduction in material sliding due to the more direct impingement of the feed material 420 on the side surface 330 of the trailing edge longitudinal bar 320 defming the hole opening 350 and the elevated longitudinal side surfaces also reduce wear on the longitudinal bars 320, as well as the circumferential bars 308. As noted above, however, the top and side surfaces 328 and 330 of the longitudinal bars 320 still may be treated with a wear resistant material, such as a PTA material described above. In some examples of this invention, the circumferential bars 308 will not need to be hardfaced and/or treated with a wear resistant material, which can save time and expense, although these bars 308 may be hardfaced and/or treated with wear resistant materials, if necessary or desired (optionally, the bars 308 may require less hardfacing and/or wear resistant material or a less expensive hardfacing and/or wear resistant material). Likewise, as illustrated in Fig.
4B, the surface 330a defming the leading edge of a hole 350 may not need to include hardfacing and/or a wear resistant material.

The hole sizes defined by bars 308 and 320 need not form squares. For example, the spacing between longitudinal bars 320 may be greater than the spacing between circumferential bars 308 in the same area. As some more specific examples, the spacings between adjacent longitudinal bars 320 may be 1.1, 1.25, 1.5, 1.75, 2, or even 2.25 times larger than the spacings between adjacent circumferential bars 308 in the same general area (e.g., around the same hole). This increased spacing between longitudinal bars 320 (particularly at the inlet end of the drum), along with the angling of these bars 320 to better match the falling angle of the material, increases the effective area of the hole thereby allowing more product to fall through the hole initially, improves product recovery or yield, and leaves less material to slide along the screen surfaces and wear them down. These spacing characteristics may be changed, if desired, along the longitudinal length of the drum (e.g., wider bar 320 spacings may be provided at the inlet end of the drum as compared to the outlet end).

There is no requirement that all example structures according to this invention require some height differential AH. Rather, if desired, in some example structures in accordance with this invention, the longitudinal bars 320 may extend into the drum's interior to the same level as the circumferential bars 308 (e.g., OH may be 0). This may be accomplished, for example, if both the circumferential bars 308 and the longitudinal bars 320 include "notches" forming the spaced apart openings 326. In such structures, the angled and spaced bars 320 and 308 defining the holes 350 would be expected to reduce material sliding along the top of the screen, e.g., due to the bar spacing features and improved material capture features described above.

The rotary breaker structures described above include additional advantages.
For example, as illustrated in Figs. 3C and 3D, the longitudinal bars 320 may have a straight or substantially straight (i. e. , non-curved) construction, and they need never be curved or bent (provided they extend in the axial direction). This feature substantially eases the production of the bars 320, which saves both time and expense. This feature also makes it easier to overlay the desired top and interior trailing edge surfaces of the longitudinal bar 320 with the hardfacing and/or wear resistant material 332 (e.g., the straight and non-curved surfaces of the longitudinal bars 320 allows PTA hardfacing and/or wear resistant material application to be easily accomplished by robotic or other automated production techniques).

Moreover, as illustrated in Fig. 3D, each longitudinal bar 320 is separate from the others and separately attached to the frame 302 and/or the circumferential bars 308.
The various longitudinal bars 320 may have the same dimensions, sizes, and/or shapes.
These modular construction features allow easier repair and replacement of individual bars 320 (as compared to repair and replacement of an entire drum section 300), which can substantially reduce down time and the time and expense associated with repairs. The ability to make interim repairs to individual bars 320 also may lengthen the overall life span of an individual section 300 of the rotary breaker drum and increase the time period between major overhauls in which the individual sections 300 of a rotary breaker need to be repaired, refurbished, or replaced.

Advantages also may be realized in the relative ease in which a manufacturer or on-site production manager can select, control, and/or change the size of the process holes 350, select, control, and/or change the angles a and (i of the hole's trailing edge, and/or select, control, and/or change the longitudinal bar 320's overall height H2. In conventional rotary breaker drums in which the through holes are permanently and integrally formed in the dnim screen structure, the hole sizes cannot be changed easily. An entirely new set of screens must be provided on the drum structure, with differently sized holes (or at least some of the existing holes potentially may be enlarged by cutting them larger, provided the remaining screen structure remains sufficiently strong to support the loads). In accordance with at least some examples of this invention, however, the hole sizes may be more readily selected, controlled, and/or changed. For example, screens having a desired hole size may be initially produced, on-site, by controlling the spacings and/or angles of bars 308 and/or 320, and these spacings and angles may be selected based on the characteristics of the material being mined and/or other operating conditions.
As another example, at least the longitudinal bars 320 may be relatively easily removed from the frame 302 and/or the circumferential bars 308 (e.g., by unbolting or otherwise loosening a mechanical connector, by a cutting torch, etc.), at least some of the longitudinal bars 320 may be repositioned (to thereby change the hole size), and the longitudinal bars 320 may be reengaged with the frame 302 and/or circumferential bars (e.g., by mechanical connectors, by re-welding, etc.). The angles a and P of the hole 350's trailing edge and/or the height H2 may be changed by substituting one set of longitudinal bars 320 with another (e.g., by replacing one longitudinal bar 320 set with a set having different spaced apart opening 326 structures (to provide different angles a and P and/or a different height H2)). Furthermore, if desired, all (or most) of this work (e.g., by moving bars 320, by replacing one bar set 320 with another, etc.) can be conducted from the inside of the drum, optionally, while the drum section 300 remains in place in the overall rotary breaker structure. This reduces the down time and significantly eases the work involved in performing these procedures. If desired, stockpiles of longitudinal bars 320 having different heights H2, angles a and 0, and/or spaced apart opening 326 constructions may be kept so that changes in operating conditions (e.g., due to material variations) can be quickly addressed by selecting an appropriate set of longitudinal bars 320 or bar positioning features for the rotary breaker construction. These features provide a great deal of flexibility in determining hole sizes and trailing edge angles.

The reduction in wear of the circumferential bars 308 also may be a significant advantage in at least some examples of the present invention. For example, when the top interior surfaces of the longitudinal bars 320 are elevated above the top interior surfaces of the circumferential bars 308, wear on bars 308 may be reduced due to the reduced amount of material sliding along the bars 308, reduced pressure and/or impact force of feed material on the bars 308, etc. Moreover, as noted above, the enlarged openings 350 and angled trailing edges 330 capture product material more effectively and efficiently (even if the top interior surfaces of bars 308 are not lower than the top interior surfaces of bars 320), thereby reducing the volume of abrasive feed material available to slide along bars 308 and/or to impact against them.

If desired, the drum hole sizes may vary over the surface area of the drum. As one more specific example, the hole sizes may differ at the drum inlet end as compared to the drum outlet end (e.g., the openings at the inlet end may be somewhat larger than the openings at the outlet end). Also, if desired, the angle(s) a and 0 defined by the longitudinal bars 320 may differ along the axial direction of the drum (e.g., with a smaller angle a at the inlet end as compared to the outlet end, or vice versa). Other variations or patterns of variation in the hole sizes also may be used without departing from this invention.

The above description has primarily focused on rotary breaker drums having round cross sections, like those shown in Figs. 1, 2B, and 3A-3E. Other constructions are possible without departing from this invention. For example, instead of a round cross section, rotary breaker drums in accordance with at least some examples of this invention may have a polygonal cross section in which the individual screen sections 500 are flat or substantially flat. Fig. 5A shows a side view of an example rotary breaker screen section 500 similar to that shown in Fig. 3E, except in the screen section 500 shown in Fig. 5A, the side frames 302b and 302c and the circumferential bars 308 are substantially straight rather than curved as shown in Figs. 3A, 3B, 3D and 3E. The various parts in the strncture 500 of Figs. 5A and 5B are shown using the same reference numbers as used in Figs. 3A through 3E for the same or similar parts, and thus the detailed description of these same or similar parts are omitted. The structure 500 of Figs. 5A and 5B
may have any or all of the various features described above with respect to Figs. 3A
through 3E, including the various bar angle features, the various bar relative height features, the wear resistant material features, and the like.

As shown in Fig. 5B, a plurality of these individual screen section members 500 may be engaged together to form a rotary breaker drum 112 having a polygonal cross section and circumference (e.g., plural screen sections 500 in the circumferential direction and/or plural screen sections 500 in the longitudinal direction). While polygonal rotary breaker drnms 112 of this type may have any desired number of sides without departing from this invention, in some example structures according to the invention, the drum 112 will include from 3 to 30 flat sides, and preferably from 4 to 24 flat sides, or even from 6 to 18 flat sides. While an octagonal rotary drum structure 112 is shown in Fig.
5B, other example rotary drums may include 10, 12, or any other desired number of sides.
Moreover, each individual flat side of the polygon structure may be made from one or more screen section members 500 of the types described above. The interior of the drum 112 also may include lifter elements and other structures, exterior frame structures, etc., e.g., as described above.

Aspects of this invention are not limited for use with rotary breaker drums.
Rather, aspects of this invention may be used with other screening technology, such as vibratory screening systems and/or stationary screening systems, including such systems used in oil sands processing. Screen sections for vibratory screening systems and/or stationary screening systems may be flat or substantially flat, like those shown in Figs.
5A and 5B
described above for the polygonal shaped rotary drums. Figs. 6A and 6B
illustrate one example of such screens and a vibrational screening system using such screens.
As shown in Fig. 6A, screen sections 600 of this type include a raw material contact side (over which the raw material to be processed slides) and an exterior or discharge side.
The various parts in the structure 600 of Fig. 6A are shown using the same reference numbers as used in Figs. 3A through 3E for the same or similar parts, and thus the detailed description of these same or similar parts are omitted. The structure 600 of Fig.
6A may have any or all of the various features described above with respect to Figs. 3A
through 3E, including the various bar angle features, the various bar relative height features, the wear resistant material features, and the like.

Fig. 6B illustrates the use of screen sections 600 of the type shown in Fig.
6A in one example vibratory screen system 650 according to this invention. As shown, the screen sections 600 are arranged in a plurality of stages (four stages shown in Fig.
6B). Each stage may include one or more individual screen sections 600. To aid in material flow, the overall screen system 650 and/or the individual stages thereof may be arranged at an angle n with respect to a horizontal base line 652. Moreover, the overall screen system 650 and/or the individual stages thereof may be vibrated (shown in Fig. 6B by arrow 654). The non-horizontal orientation and/or the vibrational features of this screening system 650 will help move the raw material to be treated along the raw material contact surface in the raw material movement direction 656, moving from the screening system inlet end 658 to the outlet end 660. The vertical drop between screen stages also may help break up the raw material. Side walls (not shown in Fig. 6B) may be provided to keep the material to be treated on the screen surfaces. While the angle n may have any desired value without departing from this invention, in some example structures in accordance with this invention, this angle will be at least 3 from horizontal, and in some examples, at least 5 . This angle also may be in the range from 5 to 50 , and even from to 30 .

Stationary screening systems in accordance with examples of this invention may be similar to the system shown in Figs. 6A and 6B, except no vibration mechanism is provided to vibrate the individual screen sections 600 or the overall screening system 650. To help the material move through such systems, the screen sections and/or overall system may be angled more than a typical vibrational screening system (e.g., the angle rc may be at least 15 from horizontal, and in some examples, at least 20 ). This angle also may be in the range from 25 to 50 , and even from 30 to 45 . If desired, baffles may be provided along the material flow path to slow the material drop rate and to help break up the raw material.

These flat screens used in vibratory or stationary processing systems can gain benefits by using the same constructions as described in more detail above for the rotary breaker drums. For example, the equivalent of the "longitudinal" bars (i.e., the bars that are transverse to the sliding of the material across the screen to effect the desired separation, which in this case are transverse to the general flow of the material) can be inclined (and/or can extend above the so-called "transverse" bars) to achieve the same benefits as discussed above.

III. Conclusion The present invention is described above and in the accompanying drawings with reference to a variety of example structures, features, elements, and combinations of structures, features, and elements. The purpose served by the disclosure, however, is to provide examples of the various features and concepts related to the invention, not to limit the scope of the invention. One skilled in the relevant art will recognize that numerous variations and modifications may be made to the example structures described above without departing from the scope of the present invention. For example, the various features and concepts described above in conjunction with this invention may be used individually and/or in any combination or subcombination without departing from at least some aspects of this invention. Additionally, the fabrication procedures may be changed, changed in order, or otherwise modified without departing from at least some aspects of this invention. As yet another example, if desired, the screens may be sized, shaped, and joined together such that the overall rotary breaker has somewhat of a conical or truncated conical structure (i. e. , the cross-sectional radius at one end may be greater than the cross-sectional radius at the other end). Other variations also are possible without departing from this invention.

Claims

WE CLAIM:

1. A section of a screen for a rotary breaker drum, comprising:
a frame member including a first frame element at a first side of the frame member and a second frame element opposite the first frame element and at a second side of the frame member;
a first circumferential bar engaged with and extending between the first frame element and the second frame element;
a second circumferential bar engaged with and extending between the first frame element and the second frame element;
a first longitudinal bar extending across the first and second circumferential bars; and a second longitudinal bar extending across the first and second circumferential bars, wherein the first and second circumferential bars and the first and second longitudinal bars define a first opening in the section of the screen.

2. A section of a screen according to claim 1, wherein each of the first and second longitudinal bars includes: (a) a first portion including a continuous metal construction that extends in a longitudinal direction, and (b) a second portion extending from the first portion, wherein the second portion includes a first opening and a second opening defined therein that are spaced apart in the longitudinal direction of the second portion, and wherein the first circumferential bar is received in the first openings of the first and second longitudinal bars and the second circumferential bar is received in the second openings of the first and second longitudinal bars.

3. A section of a screen according to claim 2, wherein the first portions of the first and second longitudinal bars are located on an interior side of the frame member so as to form a portion of an interior surface of the rotary breaker drum.

4. A section of a screen according to claim 3, further comprising:
a wear resistant material engaged with the first portions of the first and second longitudinal bars.

5. A section of a screen according to claim 3, and wherein the first portions of the first and second longitudinal bars each defines a top surface and a first side surface extending in the longitudinal direction, and wherein the section of the screen further comprises:

a first wear resistant material engaged with the first portion of the first longitudinal bar and overlaying at least a portion of the first side surface of the first longitudinal bar; and a second wear resistant material engaged with the first portion of the second longitudinal bar and overlaying at least a portion of the first side surface of the second longitudinal bar.

6. A section of a screen according to claim 1, wherein each of the first and second longitudinal bars is straight in its longitudinal direction.

7. A section of a screen according to claim 1, wherein the frame member and the first and second circumferential bars define an interior side and an exterior side, and wherein at least a portion of each of the first and second longitudinal bars extends toward the interior side of the screen to a location beyond a surface of the first circumferential bar.

8. A section of a screen according to claim 7, wherein the first longitudinal bar defines a leading edge of the first opening in the screen with respect to a rotational direction of the screen, the second longitudinal bar defines a trailing edge of the first opening with respect to the rotational direction, and wherein the first and second circumferential bars define side edges of the first opening with respect to the rotational direction.

9. A section of a screen according to claim 8, wherein an angle between the trailing edge of the first opening and a top surface of the first circumferential bar at a junction between the trailing edge and the first circumferential bar is in a range of 30° to 80°.

10. A section of a screen according to claim 8, wherein an angle between the trailing edge of the first opening and a top surface of the first circumferential bar at a junction between the trailing edge and the first circumferential bar is in a range of 30° to 60°.

11. A section of a screen according to claim 8, wherein the first longitudinal bar defines a trailing edge of a second opening in the screen located forward of the first opening with respect to the rotational direction of the screen, wherein the second opening is defined by the first longitudinal bar, the first and second circumferential bars, and a third longitudinal bar extending across the first and second circumferential bars and located forward of the first longitudinal bar with respect to the rotational direction of the screen.

12. A section of a screen according to claim 8, wherein the first circumferential bar has a thickness in a radial direction of H and the first longitudinal bar has a thickness in the radial direction of at least 1.2H.

13. A section of a screen according to claim 8, wherein the first circumferential bar has a thickness in a radial direction of H and the first longitudinal bar has a thickness in the radial direction of at least 1.75H.

14. A section of a screen according to claim 8, further comprising:
a wear resistant material engaged with the second longitudinal bar such that at least the trailing edge of the first opening includes the wear resistant material thereon.

15. A section of a screen according to claim 14, wherein no separate wear resistant material is applied to either of the first circumferential bar or the second circumferential bar.

16. A section of a screen according to claim 8, wherein the first portion of the second longitudinal bar defines a top surface and a first side surface extending in the longitudinal direction, and wherein the section of the screen further comprises:
a wear resistant material engaged with the first portion of the second longitudinal bar and overlaying at least a portion of the top surface and the first side surface of the second longitudinal bar.

17. A section of a screen according to claim 8, wherein the first portion of the second longitudinal bar defines a top surface and a first side surface extending in the longitudinal direction, and wherein the section of the screen further comprises:
a wear resistant material engaged with the first portion of the second longitudinal bar and overlaying at least a portion of the first side surface of the second longitudinal bar.

18. A section of a screen according to claim 1, further comprising:
a third circumferential bar engaged with and extending between the first frame element and the second frame element;
a fourth circumferential bar engaged with and extending between the first frame element and the second frame element;
a third longitudinal bar extending across the first, second, third, and fourth circumferential bars; and a fourth longitudinal bar extending across the first, second, third, and fourth circumferential bars, wherein the first and second longitudinal bars additionally extend across the third and fourth circumferential bars, and wherein the first, second, third, and fourth circumferential bars and the first, second, third, and fourth longitudinal bars define a plurality of adjacent openings, including the first opening, in the section of the screen.

19. A rotary breaker drum, comprising:
a first circumferential section including a plurality of sections of screen according to claim 1 arranged to form a first enclosed section; and a second circumferential section including a plurality of sections of screen according to claim 1 arranged to form a second enclosed section, wherein the second circumferential section is located longitudinally adjacent to the first circumferential section.

20. A method of making a rotary breaker drum, comprising:
arranging a plurality of sections of screen according to claim 1 together in a circumferential direction and a longitudinal direction to thereby form an enclosed cylindrical structure.

21. A method of forming a section of a screen for a rotary breaker drum, comprising:
forming a frame member including a first frame element at a first side of the frame member and a second frame element opposite the first frame element and at a second side of the frame member;
securing a first circumferential bar with the first frame element and the second frame element;
securing a second circumferential bar with the first frame element and the second frame element;
securing a first longitudinal bar to the frame member such that it extends across the first and second circumferential bars; and securing a second longitudinal bar to the frame member such that it extends across the first and second circumferential bars, wherein the first and second circumferential bars and the first and second longitudinal bars define a first opening in the section of the screen.

22. A method according to claim 21, wherein each of the first and second longitudinal bars includes: (a) a first portion including a continuous metal construction that extends in a longitudinal direction, and (b) a second portion extending from the first portion, wherein the second portion includes a first opening and a second opening defined therein that are spaced apart in the longitudinal direction of the second portion, wherein the securing of the first longitudinal bar includes placing the first circumferential bar in the first opening of the first longitudinal bar and placing the second circumferential bar in the second opening of the first longitudinal bar, and wherein the securing of the second longitudinal bar includes placing the first circumferential bar in the first opening of the second longitudinal bar and placing the second circumferential bar in the second opening of the second longitudinal bar.

23. A method according to claim 22, wherein the first portions of the first and second longitudinal bars are located on an interior side of the frame member so as to form a portion of an interior surface of the rotary breaker drum, and wherein the method further comprises:
engaging a wear resistant material with the first portions of each of the first and second longitudinal bars.

24. A method according to claim 23, wherein the first portions of the first and second longitudinal bars each define a top surface and a first side surface extending in the longitudinal direction, and wherein the method further comprises:
engaging a first wear resistant material with the first portion of the first longitudinal bar such that the first wear resistant material overlays at least a portion of the first side surface of the first longitudinal bar; and engaging a second wear resistant material with the first portion of the second longitudinal bar such that the second wear resistant material overlays at least a portion of the first side surface of the second longitudinal bar.

25. A method according to claim 21, wherein each of the first and second longitudinal bars is straight in its longitudinal direction.

26. A method according to claim 21, wherein the frame member and the first and second circumferential bars define an interior side and an exterior side, and wherein each of the first and second longitudinal bars is secured such that at least a portion of the first and second longitudinal bars extend toward the interior side of the screen to a location beyond a surface of the first circumferential bar.

27. A method according to claim 26, wherein the first longitudinal bar is secured with the frame member so as to define a leading edge of the first opening in the screen with respect to a rotational direction of the screen, the second longitudinal bar is secured with the frame member so as to define a trailing edge of the first opening with respect to the rotational direction, and wherein the first and second circumferential bars are secured with the frame member so as to define side edges of the first opening with respect to the rotational direction.

28. A method according to claim 27, wherein the second longitudinal bar and the first circumferential bar are secured with the frame member such that an angle between the trailing edge of the first opening and a top surface of the first circumferential bar at a junction between the trailing edge and the first circumferential bar is in a range of 30° to 80°.

29. A method according to claim 27, wherein the second longitudinal bar and the first circumferential bar are secured with the frame member such that an angle between the trailing edge of the first opening and a top surface of the first circumferential bar at a junction between the trailing edge and the first circumferential bar is in a range of 30° to 60°.

30. A method according to claim 27, further comprising:
securing a third longitudinal bar with the frame member such that it extends across the first and second circumferential bars at a location forward of the first longitudinal bar with respect to a rotation direction of the screen, wherein the first longitudinal bar, the third longitudinal bar, the first circumferential bar, and the second circumferential bar define a second opening in the screen located forward of the first opening with respect to the rotational direction of the screen, and wherein the first longitudinal bar defines a trailing edge of the second opening with respect to the rotational direction, the third longitudinal bar defines a leading edge of the second opening with respect to the rotational direction, and the first and second circumferential bars define side edges of the second opening.

31. A method according to claim 27, wherein the first circumferential bar has a thickness in a radial direction of H and the first longitudinal bar has a thickness in the radial direction of at least 1.2H.

32. A method according to claim 27, wherein the first circumferential bar has a thickness in a radial direction of H and the first longitudinal bar has a thickness in the radial direction of at least 1.75H.

33. A method according to claim 27, further comprising:

engaging a wear resistant material with the second longitudinal bar such that at least the trailing edge of the first opening includes the wear resistant material thereon.

34. A method according to claim 33, wherein no separate wear resistant material is applied to either of the first circumferential bar or the second circumferential bar.

35. A method according to claim 27, wherein the first portion of the second longitudinal bar defines a top surface and a first side surface extending in the longitudinal direction, and wherein the method further comprises:
engaging a wear resistant material with the first portion of the second longitudinal bar so as to overlay at least a portion of the top surface and the first side surface of the second longitudinal bar.

36. A method according to claim 27, wherein the first portion of the second longitudinal bar defines a top surface and a first side surface extending in the longitudinal direction, and wherein the method further comprises:
engaging a wear resistant material with the first portion of the second longitudinal bar so as to overlay at least a portion of the first side surface of the second longitudinal bar.

37. A method according to claim 21, further comprising:
securing a third circumferential bar with the first frame element and the second frame element;
securing a fourth circumferential bar with the first frame element and the second frame element;
securing a third longitudinal bar to the frame member such that it extends across the first, second, third, and fourth circumferential bars; and securing a fourth longitudinal bar to the frame member such that it extends across the first, second, third, and fourth circumferential bars, wherein the first and second longitudinal bars additionally extend across the third and fourth circumferential bars, and wherein the first, second, third, and fourth circumferential bars and the first, second, third, and fourth longitudinal bars define a plurality of adjacent openings, including the first opening, in the section of the screen.

38. A section of a screen for a rotary breaker drum, comprising:

a frame member including a plurality of openings defined therein, wherein at least a first opening of the plurality of openings is defined by:
a first circumferential side, a second circumferential side opposite the first circumferential side, a first longitudinal side extending between the first and second circumferential sides to define a leading edge of the first opening with respect to a rotational direction of the rotary breaker drum, and a second longitudinal side extending between the first and second circumferential sides and opposite the first longitudinal side, wherein the second longitudinal side defines a trailing edge of the first opening with respect to the rotational direction of the rotary breaker drum, and wherein an angle between the second longitudinal side and a top surface of the first circumferential side of the first opening is in a range of 30° to less than 90°.

39. A rotary breaker drum, comprising:
a first circumferential section including a plurality of sections of screen according to claim 38 arranged to form a first enclosed section; and a second circumferential section including a plurality of sections of screen according to claim 38 arranged to form a second enclosed section, wherein the second circumferential section is located longitudinally adjacent to the first circumferential section.

40. A method of making a rotary breaker drum, comprising:
arranging a plurality of sections of screen according to claim 28 together in a circumferential direction and a longitudinal direction to thereby form an enclosed cylindrical structure.

41. A section of a screen for a rotary breaker drum, comprising:
a frame member including a plurality of openings defined therein, wherein the frame member includes an interior side and an exterior side, wherein a first opening of the plurality of openings is defined by:
a first circumferential side, a second circumferential side opposite the first circumferential side, a first longitudinal side extending between the first and second circumferential sides to define a leading edge of the first opening with respect to a rotational direction of the rotary breaker drum, and a second longitudinal side extending between the first and second circumferential sides and opposite the first longitudinal side, wherein the second longitudinal side defines a trailing edge of the first opening with respect to the rotational direction of the rotary breaker drum, and wherein the second longitudinal side extends toward the interior side to a greater height than the first or second circumferential sides.

42. A rotary breaker drum, comprising:
a first circumferential section including a plurality of sections of screen according to claim 41 arranged to form a first enclosed section; and a second circumferential section including a plurality of sections of screen according to claim 41 arranged to form a second enclosed section, wherein the second circumferential section is located longitudinally adjacent to the first circumferential section.

43. A method of making a rotary breaker drum, comprising:
arranging a plurality of sections of screen according to claim 41 together in a circumferential direction and a longitudinal direction to thereby form an enclosed cylindrical structure.

44. A method of repairing a section of a screen for a rotary breaker drum, wherein the section of the screen includes: (a) a frame member having a first frame element at a first side of the frame member and a second frame element opposite the first frame element and at a second side of the frame member, (b) a first circumferential bar engaged with and extending between the first frame element and the second frame element, (c) a second circumferential bar engaged with and extending between the first frame element and the second frame element, (d) a first longitudinal bar extending across the first and second circumferential bars, and (e) a second longitudinal bar extending across the first and second circumferential bars, wherein the first and second circumferential bars and the first and second longitudinal bars define a first opening in the section of the screen, and wherein the method comprises:
disengaging the second longitudinal bar from the screen section; and engaging a third longitudinal bar with the screen section such that the third longitudinal bar extends across the first and second circumferential bars, wherein the first and second circumferential bars and the first and third longitudinal bars define the first opening in the section of the screen.

45. A method of repairing a section of a screen for a rotary breaker drum, wherein the section of the screen includes: (a) a frame member having a first frame element at a first side of the frame member and a second frame element opposite the first frame element and at a second side of the frame member, (b) a first circumferential bar engaged with and extending between the first frame element and the second frame element, (c) a second circumferential bar engaged with and extending between the first frame element and the second frame element, (d) a first longitudinal bar extending across the first and second circumferential bars, and (e) a second longitudinal bar extending across the first and second circumferential bars, wherein the first and second circumferential bars and the first and second longitudinal bars define a first opening in the section of the screen, and wherein the method comprises:
disengaging the first longitudinal bar from the screen section;
disengaging the second longitudinal bar from the screen section;
engaging a third longitudinal bar with the screen section such that the third longitudinal bar extends across the first and second circumferential bars; and engaging a fourth longitudinal bar with the screen section such that the fourth longitudinal bar extends across the first and second circumferential bars, wherein the first and second circumferential bars and the third and fourth longitudinal bars define the first opening in the section of the screen.

46. A method of repairing a section of a screen for a rotary breaker drum, wherein the section of the screen includes a plurality of openings defined therein, wherein a first opening of the plurality of openings is defined in part by a first longitudinal bar extending across the section of the screen, and wherein the method comprises:
disengaging the first longitudinal bar from the section of the screen; and engaging a second longitudinal bar with the section of the screen such that the second longitudinal bar replaces the first longitudinal bar and partially defines the first opening in the section of the screen.

47. A method of repairing a section of a screen for a rotary breaker drum, wherein the section of the screen includes a plurality of openings defined therein, wherein a first opening of the plurality of openings is defined in part by a first longitudinal bar extending across the section of the screen and a second longitudinal bar extending across the section of the screen, and wherein the method comprises:
disengaging the first longitudinal bar from the section of the screen;
disengaging the second longitudinal bar from the section of the screen;
engaging a third longitudinal bar with the section of the screen such that the third longitudinal bar replaces the first longitudinal bar; and engaging a fourth longitudinal bar with the section of the screen such that the fourth longitudinal bar replaces the second longitudinal bar, wherein the third and fourth longitudinal bars partially define the first opening in the section of the screen.

48. A section of a screen for oil sands processing equipment, comprising:
a frame member including a first frame element at a first side of the frame member and a second frame element opposite the first frame element and at a second side of the frame member;
a first transverse bar engaged with and extending between the first frame element and the second frame element;
a second transverse bar engaged with and extending between the first frame element and the second frame element;
a first longitudinal bar extending across the first and second transverse bars; and a second longitudinal bar extending across the first and second transverse bars, wherein the first and second transverse bars and the first and second longitudinal bars define a first opening in the section of the screen.

49. A section of a screen according to claim 48, wherein each of the first and second longitudinal bars includes: (a) a first portion including a continuous metal construction that extends in a longitudinal direction, and (b) a second portion extending from the first portion, wherein the second portion includes a first opening and a second opening defined therein that are spaced apart in the longitudinal direction of the second portion, and wherein the first transverse bar is received in the first openings of the first and second longitudinal bars and the second transverse bar is received in the second openings of the first and second longitudinal bars.

50. A section of a screen according to claim 48, wherein each of the first and second longitudinal bars and each of the first and second transverse bars is straight in its longitudinal direction.

51. A section of a screen according to claim 48, wherein the screen defines a raw material contact side and an exterior side, and wherein at least a portion of each of the first and second longitudinal bars extends toward the raw material contact side of the screen to a location beyond a top surface of the first transverse bar.

52. A section of a screen according to claim 51, wherein the first longitudinal bar defines a leading edge of the first opening in the screen with respect to a raw material movement direction, the second longitudinal bar defines a trailing edge of the first opening with respect to the raw material movement direction, and wherein the first and second transverse bars define side edges of the first opening with respect to the raw material movement direction.

53. A section of a screen according to claim 52, wherein an angle between the trailing edge of the first opening and the top surface of the first transverse bar at a junction between the trailing edge and the first transverse bar is in a range of 30° to 80°.

54. A section of a screen according to claim 52, wherein an angle between the trailing edge of the first opening and the top surface of the first transverse bar at a junction between the trailing edge and the first transverse bar is in a range of 30° to 60°.

55. A section of a screen according to claim 52, wherein the first longitudinal bar defines a trailing edge of a second opening in the screen located forward of the first opening with respect to the raw material movement direction, wherein the second opening is defined by the first longitudinal bar, the first and second transverse bars, and a third longitudinal bar extending across the first and second transverse bars and located forward of the first longitudinal bar with respect to the raw material movement direction.

56. A section of a screen according to claim 48, further comprising:
a third transverse bar engaged with and extending between the first frame element and the second frame element;
a fourth transverse bar engaged with and extending between the first frame element and the second frame element;

a third longitudinal bar extending across the first, second, third, and fourth transverse bars; and a fourth longitudinal bar extending across the first, second, third, and fourth transverse bars, wherein the first and second longitudinal bars additionally extend across the third and fourth transverse bars, and wherein the first, second, third, and fourth transverse bars and the first, second, third, and fourth longitudinal bars define a plurality of adjacent openings, including the first opening, in the section of the screen.

57. A method of forming a section of a screen for oil sands processing equipment, comprising:
forming a frame member including a first frame element at a first side of the frame member and a second frame element opposite the first frame element and at a second side of the frame member;
securing a first transverse bar with the first frame element and the second frame element;
securing a second transverse bar with the first frame element and the second frame element;
securing a first longitudinal bar to the frame member such that it extends across the first and second transverse bars; and securing a second longitudinal bar to the frame member such that it extends across the first and second transverse bars, wherein the first and second transverse bars and the first and second longitudinal bars define a first opening in the section of the screen.

58. A method according to claim 57, wherein each of the first and second longitudinal bars includes: (a) a first portion including a continuous metal construction that extends in a longitudinal direction, and (b) a second portion extending from the first portion, wherein the second portion includes a first opening and a second opening defined therein that are spaced apart in the longitudinal direction of the second portion, wherein the securing of the first longitudinal bar includes placing the first transverse bar in the first opening of the first longitudinal bar and placing the second transverse bar in the second opening of the first longitudinal bar, and wherein the securing of the second longitudinal bar includes placing the first transverse bar in the first opening of the second longitudinal bar and placing the second transverse bar in the second opening of the second longitudinal bar.

59. A method according to claim 57, wherein each of the first and second longitudinal bars and each of the first and second transverse bars is straight in its longitudinal direction.

60. A method according to claim 57, wherein the screen defines a raw material contact side and an exterior side, and wherein each of the first and second longitudinal bars is secured such that at least a portion of the first and second longitudinal bars extends toward the raw material contact side of the screen to a location beyond a top surface of the first transverse bar.

61. A method according to claim 60, wherein the first longitudinal bar is secured with the frame member so as to define a leading edge of the first opening in the screen with respect to a raw material movement direction, the second longitudinal bar is secured with the frame member so as to define a trailing edge of the first opening with respect to the raw material movement direction, and wherein the first and second transverse bars are secured with the frame member so as to define side edges of the first opening with respect to the raw material movement direction.

62. A method according to claim 61, wherein the second longitudinal bar and the first transverse bar are secured with the frame member such that an angle between the trailing edge of the first opening and the top surface of the first transverse bar at a junction between the trailing edge and the first transverse bar is in a range of 30° to 80°.

63. A method according to claim 61, wherein the second longitudinal bar and the first transverse bar are secured with the frame member such that an angle between the trailing edge of the first opening and the top surface of the first transverse bar at a junction between the trailing edge and the first transverse bar is in a range of 30° to 60°.

64. A method according to claim 61, further comprising:
securing a third longitudinal bar with the frame member such that it extends across the first and second transverse bars at a location forward of the first longitudinal bar with respect to the raw material movement direction, wherein the first longitudinal bar, the third longitudinal bar, the first transverse bar, and the second transverse bar define a second opening in the screen located forward of the first opening with respect to raw material movement direction, and wherein the first longitudinal bar defines a trailing edge of the second opening with respect to the raw material movement direction, the third longitudinal bar defines a leading edge of the second opening with respect to the raw material movement direction, and the first and second transverse bars define side edges of the second opening.

65. A method according to claim 57, further comprising:
securing a third transverse bar with the first frame element and the second frame element;
securing a fourth transverse bar with the first frame element and the second frame element;
securing a third longitudinal bar to the frame member such that it extends across the first, second, third, and fourth transverse bars; and securing a fourth longitudinal bar to the frame member such that it extends across the first, second, third, and fourth transverse bars, wherein the first and second longitudinal bars additionally extend across the third and fourth transverse bars, and wherein the first, second, third, and fourth transverse bars and the first, second, third, and fourth longitudinal bars define a plurality of adjacent openings, including the first opening, in the section of the screen.

66. A section of a screen for oil sands processing equipment, comprising:
a frame member including a plurality of openings defined therein, wherein at least a first opening of the plurality of openings is defined by:
a first transverse side, a second transverse side opposite the first transverse side, a first longitudinal side extending between the first and second transverse sides to define a leading edge of the first opening with respect to a raw material movement direction, and a second longitudinal side extending between the first and second transverse sides and opposite the first longitudinal side, wherein the second longitudinal side defines a trailing edge of the first opening with respect to the raw material movement direction, and wherein an angle between the second longitudinal side and a top surface of the first transverse side of the first opening is in a range of 30° to less than 90°.

67. A section of a screen for oil sands processing equipment, comprising:

a frame member including a plurality of openings defined therein, wherein the frame member includes a raw material contact side and an exterior side, wherein a first opening of the plurality of openings is defined by:
a first transverse side, a second transverse side opposite the first transverse side, a first longitudinal side extending between the first and second transverse sides to define a leading edge of the first opening with respect to a raw material movement direction, and a second longitudinal side extending between the first and second transverse sides and opposite the first longitudinal side, wherein the second longitudinal side defines a trailing edge of the first opening with respect to the raw material movement direction, and wherein the second longitudinal side extends toward the raw material contact side to a greater height than the first or second transverse sides.

68. A method of repairing a section of a screen for oil sands processing equipment, wherein the section of the screen includes: (a) a frame member having a first frame element at a first side of the frame member and a second frame element opposite the first frame element and at a second side of the frame member, (b) a first transverse bar engaged with and extending between the first frame element and the second frame element, (c) a second transverse bar engaged with and extending between the first frame element and the second frame element, (d) a first longitudinal bar extending across the first and second transverse bars, and (e) a second longitudinal bar extending across the first and second transverse bars, wherein the first and second transverse bars and the first and second longitudinal bars define a first opening in the section of the screen, and wherein the method comprises:
disengaging the second longitudinal bar from the screen section; and engaging a third longitudinal bar with the screen section such that the third longitudinal bar extends across the first and second transverse bars, wherein the first and second transverse bars and the first and third longitudinal bars define the first opening in the section of the screen.

69. A method of repairing a section of a screen for oil sands processing equipment, wherein the section of the screen includes: (a) a frame member having a first frame element at a first side of the frame member and a second frame element opposite the first frame element and at a second side of the frame member, (b) a first transverse bar engaged with and extending between the first frame element and the second frame element, (c) a second transverse bar engaged with and extending between the first frame element and the second frame element, (d) a first longitudinal bar extending across the first and second transverse bars, and (e) a second longitudinal bar extending across the first and second transverse bars, wherein the first and second transverse bars and the first and second longitudinal bars define a first opening in the section of the screen, and wherein the method comprises:
disengaging the first longitudinal bar from the screen section;
disengaging the second longitudinal bar from the screen section;
engaging a third longitudinal bar with the screen section such that the third longitudinal bar extends across the first and second transverse bars; and engaging a fourth longitudinal bar with the screen section such that the fourth longitudinal bar extends across the first and second transverse bars, wherein the first and second transverse bars and the third and fourth longitudinal bars define the first opening in the section of the screen.

70. A method of repairing a section of a screen for oil sands processing equipment, wherein the section of the screen includes a plurality of openings defined therein, wherein a first opening of the plurality of openings is defined in part by a first longitudinal bar extending across the section of the screen, and wherein the method comprises:
disengaging the first longitudinal bar from the section of the screen; and engaging a second longitudinal bar with the section of the screen such that the second longitudinal bar replaces the first longitudinal bar and partially defines the first opening in the section of the screen.

71. A method of repairing a section of a screen for oil sands processing equipment, wherein the section of the screen includes a plurality of openings defined therein, wherein a first opening of the plurality of openings is defined in part by a first longitudinal bar extending across the section of the screen and a second longitudinal bar extending across the section of the screen, and wherein the method comprises:
disengaging the first longitudinal bar from the section of the screen;
disengaging the second longitudinal bar from the section of the screen;

engaging a third longitudinal bar with the section of the screen such that the third longitudinal bar replaces the first longitudinal bar; and engaging a fourth longitudinal bar with the section of the screen such that the fourth longitudinal bar replaces the second longitudinal bar, wherein the third and fourth longitudinal bars partially define the first opening in the section of the screen.