Tensioning mechanism for belt-type triboelectric separator device

Abstract

An improved belt separator system and method for separating particle mixtures based on triboelectric separation of particles is disclosed. The separator system includes a tensioning system embodying a tensioning roller and a two-piece rotating shaft assembly. The rotating shaft assembly includes an inner shaft coupled to an outer shaft. The inner shaft is rotated with an actuator. The outer shaft is sized to receive the inner shaft therein and is coupled to a pair of rotating disks.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 831,329, filed April 9, 2019, and entitled "TENSION MECHANISM FOR BELT-TYPE TRIBOELECTRIC SEPARATOR DEVICES," the entire disclosure of which is incorporated herein by reference in its entirety for all purposes.

[0002] FIELD OF THE PRESENT APPLICATION The present invention relates to a tensioning mechanism for a belt-type triboelectric separator system, for example, to providing triboelectric charging and subsequent triboelectric separation of particles using a belt separating device. [Background technology]

[0003] Belt separator systems (BSS) are used to separate components of a particle mixture based on charging of the different components by surface contact (i.e., triboelectric effect). FIG. 1 shows a belt separator system as disclosed in commonly owned U.S. Pat. Nos. 4,839,032 and 4,874,507, which are incorporated herein by reference in their entirety. One embodiment of the belt separator system includes parallel spaced electrodes 10 and 12 arranged longitudinally and defining a process chamber 14 having a longitudinal centerline 16, and a belt 18 traveling longitudinally between the spaced electrodes parallel to the longitudinal centerline. The belt 18 forms a continuous loop, which is driven by a pair of end rollers 20, 22. The particle mixture is loaded onto the belt 18 in a feed region 11 between the electrodes 10. The belt 18 includes counter-traveling belt sections 18A and 18B moving in opposite directions to transport the components of the particle mixture along the length of the electrodes 10 and 12. The only moving part of the BSS is the belt 18, which moves at high speeds, e.g., about 40 miles per hour, in an extremely abrasive environment. Two belt sections 18A, 18B move in opposite directions, parallel to the centerline 16.

[0004] In one embodiment, a negative voltage is applied to the upper electrode 10 and a positive voltage is applied to the lower electrode 12, causing feed particles with a positive charge to be attracted toward the negative upper electrode and feed particles with a negative charge to be attracted in the opposite direction. When the upper belt section 18A sweeps to the right and the lower belt section 18B sweeps to the left, material exiting the right side of the process chamber 14 is enriched with positively charged particles, while material exiting the left side is enriched with negatively charged particles.

[0005] As an example, fly ash containing a mixture of carbon and silica particles can be introduced into the process chamber 14 and the agitation of particle-particle, particle-belt and particle-wall collisions in a strong electric field combined with the movement of the belt 18 results in one output stream being enriched in carbon and the other enriched in silica compared to the original feed.

[0006] In one known embodiment, the belt 18 shown in FIG. 1 has four rollers, two drive rollers 20 and 22 and two idler rollers 20A and 22A. With this basic configuration, belt tensioning is accomplished using a linear actuator(s) connected to the drive rollers and moving them along the same axis as the belt motion. In another known embodiment, two additional idler rollers, called tensioning rollers, can be moved to maintain tension in the belt loops even with substantial stretching of the belt. FIG. 2 illustrates the belt 18 and tensioning rollers 24, 26. The two additional tensioning rollers 24, 26 are the top rollers, and the tensioning mechanism moves these two rollers in a rotary motion to tension the belt 18.

[0007] The belt 18 requires tension at all times during material processing to prevent slipping on the two drive rollers 20, 22 and is therefore pre-tensioned. Drag forces generated on the belt 18, particularly inside the process chamber 14, add additional tension to the belt in sections with belt loops. Current production belts are made from plastic materials that undergo substantial stretching over hundreds of hours of operation due to belt tension. Current systems can accommodate approximately 20 inches of belt stretch on each side of the belt for a total stretch of roughly 40 inches.

[0008] In addition, referring to Figure 3, in known embodiments, each tensioning roller 24, 26 is mounted on two rotating disks, the adjacent rotating disk being shown at 28 in Figure 3, which currently requires an elaborate tensioning mechanism to ensure that both rotating disks rotate the same amount to avoid misalignment of the tensioning rollers with respect to the belt 18. If the tensioning rollers are out of alignment, the belt 18 will not track properly and may crash into one side wall of the process chamber 14. This tensioning mechanism for coupling to the rotating disk movement is shown in Figure 3. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] U.S. Pat. No. 4,839,032 [Patent Document 2] U.S. Pat. No. 4,874,507 Summary of the Invention [Means for solving the problem]

[0010] Aspects and embodiments are directed to a system for delivering a tensioning mechanism for a belt-type triboelectric separator system.

[0011] One aspect of the present disclosure is directed to a tensioning mechanism for tensioning an endless belt. In one embodiment, the tensioning mechanism includes a tensioning roller configured to apply tension to the belt, a pair of rotating disks coupled to the tensioning roller at each end of the tensioning roller configured to move the tensioning roller to apply tension to the belt, and a rotating shaft assembly coupled to the pair of rotating disks. The rotating shaft assembly includes an inner shaft coupled to an outer shaft. The inner shaft is rotated with an actuator. The outer shaft is sized to receive the inner shaft therein and coupled to the pair of rotating disks. The rotating shaft assembly is configured such that both rotating disks of the pair of rotating disks experience approximately the same angular deflection relative to an outer end of the inner shaft when each disk applies an equal amount of torque on the rotating shaft assembly relative to an opposing torque applied by the actuator on the inner shaft.

[0012] An embodiment of the tensioning mechanism may further include holding the pair of rotating disks coaxially with the rotating shaft assembly by bearings on the periphery of the pair of rotating disks. One rotating disk of the pair of rotating disks may be configured to be removed from both the tensioning roller and the rotating shaft assembly and moved apart so that the belt can be disengaged from the tensioning roller and the other rollers defining the belt loop without removing the belt roller. The pair of rotating disks may function as part of the enclosure. The rotating shaft assembly may be locked to the pair of rotating disks during belt operation such that in the event of an explosion or other event inside the enclosure that generates a separating axial force on the rotating members, the rotating shaft assembly holds the pair of rotating disks together. The tensioning mechanism is included in a belt separator system, the belt separator system comprising a first set of two rollers at a first end of the belt separator system and a second set of two rollers at a second end of the belt separator system, the first set of two rollers not including tensioning rollers and the second set of two rollers including tensioning rollers. The drive rollers on the first side may be operated with a motor torque applied substantially more than the drive rollers on the second side such that the motor torque applied on each roller is approximately proportional to the roller circumference in intimate contact with the belt. The outer end of the inner shaft may be held coaxially with the closer end of the outer shaft by a bearing structure capable of resisting radial loads. The bearing structure may consist of three or more cam followers. In another embodiment, instead of containing two rotating disks, the mechanism may have two arms mounted on the outer rotating shaft, each connected to one end of the tensioning roller such that both arms undergo the same angular deflection defined by the plane passing through the center of the tensioning roller at the end of the arm and the axis of the outer rotating shaft under equal load from the tensioning roller on the inner shaft, the outer rotating shaft being held by bearings on both ends, which constrain lateral movement but allow the outer rotating shaft to rotate on its axis. One arm can be removed from the tensioning roller so that the continuous belt can be removed from the tensioning roller without removing the tensioning roller.

[0013] Another aspect of the disclosure is directed to a belt separator system, the belt separator system including first and second electrodes arranged on opposite sides of a longitudinal centerline and configured to provide an electric field between the first and second electrodes, a first set of rollers disposed at a first end of the system, a second set of rollers disposed at a second end of the system, a continuous belt disposed between the first and second electrodes and supported by the first and second set of rollers, a separation zone defined by and between the continuous belt, and a tensioning mechanism for tensioning the continuous belt. The tensioning mechanism includes a tensioning roller configured to apply tension to the continuous belt, and a pair of rotating disks coupled to the tensioning roller at each end of the tensioning roller, the pair of rotating disks configured to move the tensioning roller to apply tension to the continuous belt. The tensioning mechanism further includes a rotating shaft assembly coupled to the pair of rotating disks. The rotating shaft assembly includes an inner shaft coupled to the outer shaft. The inner shaft is rotated using an actuator, the outer shaft is sized to receive the inner shaft therein and is coupled to a pair of rotating disks, the rotating shaft assembly being configured such that both rotating disks of the pair of rotating disks undergo approximately the same angular deflection relative to the outer end of the inner shaft when each disk imparts an equal amount of torque on the rotating shaft assembly relative to an opposing torque imparted by the actuator on the inner shaft.

[0014] The belt separator system embodiment may further include holding the pair of rotating disks coaxially with the rotating shaft assembly by bearings on the periphery of the pair of rotating disks. One rotating disk of the pair of rotating disks can be removed from both the tensioning roller and the rotating shaft assembly and moved apart so that the continuous belt can be disengaged from the tensioning roller and the first and second sets of rollers defining the belt loop without removing the roller. The pair of rotating disks can function as part of the enclosure. The rotating shaft assembly can be locked to the pair of rotating disks during operation so that in the event of an explosion or other event inside the enclosure that generates a separating axial force on the rotating members, the rotating shaft assembly holds the pair of rotating disks together. The two rollers of the first set do not include tensioning rollers, and the two rollers of the second set include tensioning rollers. The drive rollers on the first side can be operated with a motor torque applied substantially more than the drive rollers on the second side such that the motor torque applied on each roller is approximately proportional to the roller circumference in intimate contact with the continuous belt. The outer end of the inner shaft may be held coaxially with the proximal end of the outer shaft by a bearing structure capable of resisting radial loads. The bearing structure may consist of three or more cam followers.

[0015] Another aspect of the disclosure is directed to a method of fluidizing a particle mixture in a belt separator system. In one embodiment, the method includes introducing the particle mixture into a feed port of the belt separator system. The system includes a first electrode and a second electrode arranged on opposite sides of a longitudinal centerline and configured to provide an electric field between the first electrode and the second electrode, a first set of rollers disposed at a first end of the system, a second set of rollers disposed at a second end of the system, a continuous belt disposed between the first electrode and the second electrode and supported by the first set of rollers and the second set of rollers, a separation zone defined by the continuous belt and between the continuous belt, and a tensioning mechanism for tensioning the continuous belt. The tensioning mechanism includes a tensioning roller configured to apply tension to the continuous belt and a pair of rotating disks coupled to the tensioning roller at each end of the tensioning roller. The pair of rotating disks are configured to move the tensioning roller to apply tension to the continuous belt. The tensioning mechanism further includes a rotating shaft assembly coupled to the pair of rotating disks. The rotating shaft assembly includes an inner shaft coupled to the outer shaft. The inner shaft is rotated using an actuator. The outer shaft is sized to receive the inner shaft therein and coupled to the pair of rotating disks. The rotating shaft assembly is configured such that both rotating disks of the pair of rotating disks undergo approximately the same angular deflection relative to the outer end of the inner shaft when each disk exerts an equal amount of torque on the rotating shaft assembly relative to an opposing torque exerted on the inner shaft by the actuator. The method further includes providing a separating influence to at least one of the first electrode and the second electrode, separating different components of the particle mixture in the direction of the separating influence according to their relative influence on the separating influence, mechanically moving the different components of the particle mixture in a direction transverse to the separating influence, and removing the separated components from the separation chamber.

[0016] An embodiment of the method may further include holding the pair of rotating disks coaxially with the rotating shaft assembly by bearings on the periphery of the pair of rotating disks. The method may further include removing one rotating disk of the pair of rotating disks from both the tensioning roller and the rotating shaft assembly, and moving the rotating disk away so that the continuous belt can be disengaged from the tensioning roller and the first and second sets of rollers defining the belt loop without removing the roller. The method may further include locking the rotating shaft assembly to the pair of rotating disks during operation so that the rotating shaft assembly holds the pair of rotating disks together in the event of an explosion or other event inside the enclosure that generates a separating axial force on the rotating members. The method may further include providing a second set of two rollers with the tensioning roller. The method may further include operating the first side drive roller with a motor torque applied substantially more than the second side drive roller such that the motor torque applied on each roller is approximately proportional to the roller circumference in intimate contact with the continuous belt. The method may further include holding an outer end of the inner shaft coaxially with a proximal end of the outer shaft by a bearing structure capable of resisting radial loads. The present invention provides, for example, the following items. (Item 1) A tensioning mechanism for tensioning an endless belt, comprising: A tension roller configured to apply tension to the belt; a pair of rotating disks coupled to the tension roller at each end of the tension roller, the pair of rotating disks configured to move the tension roller to apply tension to the belt; a rotating shaft assembly coupled to the pair of rotating disks, the rotating shaft assembly including an inner shaft coupled to an outer shaft, the inner shaft being rotated using an actuator, the outer shaft being sized to receive the inner shaft therein and coupled to the pair of rotating disks, the rotating shaft assembly being configured such that when each disk exerts an equal amount of torque on the rotating shaft assembly relative to an opposing torque exerted by an actuator on the inner shaft, both rotating disks of the pair of rotating disks undergo approximately the same angular deflection relative to an outer end of the inner shaft; A tensioning mechanism comprising: (Item 2) 2. The tensioning mechanism of item 1, wherein the pair of rotating disks are held coaxially with the rotating shaft assembly by bearings on the periphery of the pair of rotating disks. (Item 3) 2. The tensioning mechanism of claim 1, wherein one rotating disk of the pair of rotating disks is configured to be removed from both the tensioning roller and the rotating shaft assembly and moved away such that the belt can be unhooked from the tensioning roller and other rollers defining a belt loop without removing the belt roller. (Item 4) 4. The tensioning mechanism of item 3, wherein the pair of rotating disks function as part of an enclosure, and the rotating shaft assembly is locked to the pair of rotating disks during belt operation such that in the event of an explosion or other event inside the enclosure that generates a separating axial force on the rotating members, the rotating shaft assembly holds the pair of rotating disks together. (Item 5) The tensioning mechanism is included within a belt separator system, the belt separator system comprising a first set of two rollers at a first end of the belt separator system and a second set of two rollers at a second end of the belt separator system, the first set of two rollers not including tensioning rollers and the second set of two rollers including tensioning rollers. (Item 6) The tensioning mechanism described in item 5, wherein the drive rollers on the first side are operated with a motor torque applied substantially greater than that of the drive rollers on the second side such that the motor torque applied on each roller is approximately proportional to the roller circumference when in close contact with the belt. (Item 7) 2. The tensioning mechanism of item 1, wherein the outer end of the inner shaft is held coaxially with the closer end of the outer shaft by a bearing structure capable of resisting radial loads. (Item 8) 8. The tensioning mechanism according to item 7, wherein the bearing structure comprises three or more cam followers. (Item 9) 2. The tensioning mechanism according to claim 1, wherein instead of containing two rotating disks, the mechanism has two arms mounted on the outer rotating shaft, each arm connected to one end of the tensioning roller such that both arms undergo the same angular deflection as defined by a plane passing through the center of the tensioning roller at the end of the arm and the axis of the outer rotating shaft under equal load from the tensioning roller on the inner shaft, the outer rotating shaft being held by bearings on both ends that constrain lateral movement but allow rotation of the outer rotating shaft on its axis. (Item 10) 10. The tensioning mechanism of claim 9, wherein one arm can be detached from the tensioning roller such that the continuous belt can be removed from the tensioning roller without removing the tensioning roller. (Item 11) 1. A belt separator system comprising: a first electrode and a second electrode, the first electrode and the second electrode being arranged on opposite sides of a longitudinal centerline and configured to provide an electric field between the first electrode and the second electrode; a first set of rollers disposed at a first end of the system; a second set of rollers disposed at a second end of the system; and a continuous belt disposed between the first electrode and the second electrode and supported by the first set of rollers and the second set of rollers; a separation zone defined by and between said continuous belts; A tensioning mechanism for tensioning the continuous belt, a tension roller configured to apply tension to the continuous belt; a pair of rotating disks coupled to the tension roller at each end of the tension roller, the pair of rotating disks configured to move the tension roller to apply tension to the continuous belt; a rotating shaft assembly coupled to the pair of rotating disks, the rotating shaft assembly including an inner shaft coupled to an outer shaft, the inner shaft being rotated using an actuator, the outer shaft being sized to receive the inner shaft therein and coupled to the pair of rotating disks, the rotating shaft assembly being configured such that when each disk exerts an equal amount of torque on the rotating shaft assembly relative to an opposing torque exerted by an actuator on the inner shaft, both rotating disks of the pair of rotating disks undergo approximately the same angular deflection relative to an outer end of the inner shaft; A tension mechanism including: A belt separator system comprising: (Item 12) Item 12. The belt separator system of item 11, wherein the pair of rotating disks are held coaxially with the rotating shaft assembly by bearings on the periphery of the pair of rotating disks. (Item 13) Item 12. The belt separator system of item 11, wherein one rotating disk of the pair of rotating disks can be removed from both the tensioning roller and the rotating shaft assembly and moved away such that the continuous belt can be disengaged from the tensioning roller and the first and second sets of rollers defining a belt loop without removing the rollers. (Item 14) 10. The belt separator system of claim 9, wherein the pair of rotating disks function as part of an enclosure and the rotating shaft assembly is locked to the pair of rotating disks during operation such that in the event of an explosion or other event inside the enclosure that generates a separating axial force on the rotating members, the rotating shaft assembly holds the pair of rotating disks together. (Item 15) Item 12. The belt separator system of item 11, wherein the first set of two rollers does not include a tension roller, and the second set of two rollers includes a tension roller. (Item 16) Item 16. The belt separator system of item 15, wherein the drive rollers on the first side are operated with a motor torque applied substantially greater than the drive rollers on the second side such that the motor torque applied on each roller is approximately proportional to the roller circumference in intimate contact with the continuous belt. (Item 17) Item 12. The belt separator system of item 11, wherein the outer end of the inner shaft is held coaxially with a closer end of the outer shaft by a bearing structure capable of resisting radial loads. (Item 18) Item 18. The belt separator system of item 17, wherein the bearing structure comprises three or more cam followers. (Item 19) 1. A method for fluidizing a mixture of particles in a belt separator system, the method comprising: introducing the particulate mixture into a feed port of the belt separator system, the system comprising: a first electrode and a second electrode, the first electrode and the second electrode being arranged on opposite sides of a longitudinal centerline and configured to provide an electric field between the first electrode and the second electrode; a first set of rollers disposed at a first end of the system; a second set of rollers disposed at a second end of the system; and a continuous belt disposed between the first electrode and the second electrode and supported by the first set of rollers and the second set of rollers; a separation zone defined by and between said continuous belts; A tensioning mechanism for tensioning the continuous belt, the tensioning mechanism comprising: a tension roller configured to apply tension to the continuous belt; a pair of rotating disks coupled to the tension roller at each end of the tension roller, the pair of rotating disks configured to move the tension roller to apply tension to the continuous belt; a rotating shaft assembly coupled to the pair of rotating disks, the rotating shaft assembly including an inner shaft coupled to an outer shaft, the inner shaft being rotated using an actuator, the outer shaft being sized to receive the inner shaft therein and coupled to the pair of rotating disks, the rotating shaft assembly being configured such that when each disk exerts an equal amount of torque on the rotating shaft assembly relative to an opposing torque exerted by an actuator on the inner shaft, both rotating disks of the pair of rotating disks undergo approximately the same angular deflection relative to the outer end of the inner shaft; A tension mechanism including: and providing a decoupling influence to at least one of the first electrode and the second electrode; separating different components of the particle mixture according to their relative influence on the separating influence in the direction of the separating influence; mechanically displacing the different components of the particle mixture laterally relative to the separating influence; removing the separated components from the separation chamber; A method comprising: (Item 20) 20. The method of claim 19, further comprising holding the pair of rotating disks coaxially with the rotating shaft assembly by bearings on the periphery of the pair of rotating disks. (Item 21) 21. The method of claim 20, further comprising removing one of the pair of rotating disks from both the tensioning roller and the rotating shaft assembly, and moving the rotating disk away so that the continuous belt can be unhooked from the tensioning roller and the first and second sets of rollers defining a belt loop without removing the rollers. (Item 22) 22. The method of claim 21, further comprising locking the rotating shaft assembly to the pair of rotating disks during operation such that in the event of an explosion or other event inside the enclosure that generates a separating axial force on the rotating members, the rotating shaft assembly holds the pair of rotating disks together. (Item 23) 20. The method of claim 19, further comprising providing the second set of two rollers with the tension roller. (Item 24) 24. The method of claim 23, further comprising operating the first side drive rollers with a motor torque applied substantially greater than the second side drive rollers such that the motor torque applied on each roller is approximately proportional to the roller circumference in intimate contact with the continuous belt. (Item 25) 20. The method of claim 19, further comprising holding the outer end of the inner shaft coaxially with a proximal end of the outer shaft by a bearing structure capable of resisting radial loads. (Item 26) A belt separator system including a tensioner mechanism as shown and described herein. [Brief description of the drawings]

[0017] Various aspects of at least one embodiment are discussed below with reference to the accompanying figures, which are not intended to be drawn to scale. The figures are included to provide illustrations of and further understanding of various aspects and embodiments, and are incorporated into and constitute a part of this specification, but are not intended as a definition of the limitations of the present invention. Technical features in the figures, detailed description, or any claims are followed by reference symbols, which are included for the sole purpose of increasing the clarity of the figures and descriptions. In the figures, each identical or nearly identical component shown in various figures is represented by a similar number. For purposes of clarity, all components may not be labeled in all figures.

[0018] [Figure 1] FIG. 1 is a schematic diagram of an example of a known belt separator system (BSS). [Diagram 2] FIG. 2 is a side elevational view of a known BSS tensioning system. [Diagram 3] FIG. 3 is a perspective view of an actuator system for the tensioning system shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view of a tensioning system according to one embodiment of the present disclosure. [Diagram 5] FIG. 5 is a perspective view of the components of the tensioning system shown in FIG. [Figure 6] FIG. 6 is another perspective view of the components of the tensioning system shown in FIG. [Figure 7] FIG. 7 is another perspective view of the components of the tensioning system shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Systems and methods are provided as improvements to belt separator systems and the operation of such systems. The systems and methods provided herein may improve or enhance belt separator systems through improved tensioning systems. This may allow for optimized operation of the system and reduced costs associated with operation and reduced time lost due to required equipment replacement.

[0020] It is to be understood that the embodiments of the methods and apparatus discussed herein are not limited in application to the details of construction and arrangement of components set forth in the following description or illustrated in the accompanying drawings. The methods, systems, and apparatuses are capable of implementation in other embodiments and may be practiced or carried out in various ways. Examples of specific implementations are provided herein for illustrative purposes only and are not intended to be limiting. Additionally, the phraseology and terminology used herein are for purposes of description and should not be considered limiting. The use herein of "including," "comprising," "having," "containing," "involving," and variations thereof, is meant to encompass the items listed thereafter and equivalents and additional items thereof. References to "or" may be construed as inclusive, such that any term described using "or" may indicate either a single one, more than one, and all of the described term. Any reference to any of the embodiments or elements or acts of the systems and methods herein that are referred to in the singular may also include embodiments that include a plurality of those elements, and any reference to any embodiment or element or act herein in the plural may also include embodiments that include only a single element. Any references to front and back, left and right, top and bottom, upper and lower, and vertical and horizontal are for convenience of description and are not intended to limit the systems and methods or components thereof to any one location or spatial orientation.

[0021] The present disclosure is directed to an improved tensioning mechanism for belt-type triboelectric separator systems, for example, within a triboelectric counter-current belt type separator system.

[0022] As described above, Figure 1 shows an embodiment of a BSS with a continuous counter-rotating belt 18 moving between two longitudinal parallel planar electrodes 10, 12. The belt can be made from a variety of materials. For example, a woven belt or an extruded belt can be used.

[0023] One current design of ultra-high molecular weight polyethylene (UHMWPE) belts has straight, smooth machine direction edge strands that are thicker than the machine direction or cross direction strands in the interior of the belt. These wider (20-30 mm) edge strands function to carry more of the tensile load, provide dimensional stability, and reduce the incidence of belt failure due to edge wear. Such UHMWPE sheet belts have been proven to have a much longer life than extruded belts. In some applications, such as the separation of unburned carbon from coal combustion fly ash, these UHMWPE belts have been tested and shown to have a maximum life of up to 1,950 hours before failure.

[0024] The embodiments of the present disclosure are directed to a tensioning system that replaces the external shaft and actuator hardware shown in Figure 3 and instead connects two rotating disks with a coaxial internal shaft. Due to the high torque and length of the shaft, a normal single shaft of any reasonable dimension (whether hollow or solid) can twist under torque load, causing significant deflection and tensioning roller misalignment, if a single actuator is used on one end of the shaft. The embodiments of the present disclosure solve this problem by using a hollow shaft with a secondary internal shaft.

[0025] 4, the tensioning mechanism, generally designated 50, includes a tensioning roller 52 coupled to a rotating shaft assembly including a hollow outer shaft 54 ​​and an inner shaft 56. The tensioning roller 52 and rotating shaft assembly are coupled to a pair of rotating disks 58, 60 that are mounted on the outer ends of the tensioning roller. Specifically, the outer and inner shafts 54, 56 of the rotating shaft assembly are mounted along the centerlines of the rotating disks 58, 60, and the tensioning roller 52 is mounted off-axis relative to the rotating disks.

[0026] As shown, the inner shaft 56 can twist independently of the outer shaft 54 ​​in such a way that twisting of the inner shaft does not cause a difference in the angular deflection of the two rotating disks 58, 60 carrying the tensioning roller 52. The hollow outer shaft 54 ​​also experiences torsional deflection, but the cross section of the outer shaft and its attachment to the inner shaft 56 are sized and positioned such that both rotating disks 58, 60 experience equal angular deflection under equal loads relative to the inner shaft. The tensioning system allows the outer end of the inner shaft (right side in FIG. 4) to be pivoted by a single actuator. In one embodiment, referring to FIG. 5, an air piston 62 is provided to actuate the rotating disk 58 and drive the rotation of the other rotating disk via the outer shaft 54 ​​and the inner shaft 56. Any type of drive mechanism, for example an electric screw drive or some other type of drive, can be provided in place of the air piston 62. The two rotating discs 58, 60 have the same rotational stiffness relative to the work shaft (ie, the rotating shaft assembly) so that the tension roller 52 will not become misaligned under the load of a precisely centered belt on the tension roller.

[0027] The disclosed embodiment of the tensioning system 50 allows a desired belt stretch of 40 inches to be accommodated using a single tensioning mechanism. Thus, instead of six rollers, only five belt loops can be used. One side of the tensioning system 50 includes two rollers (e.g., rollers 20A, 20B) as shown on the left in FIG. 1, while the other side of the tensioning system includes three rollers (e.g., rollers 22, 22A, 26) as shown in FIG. 2. Thus, even though the rotating disk of the three-roller side is enlarged from a diameter of about 20 inches to a diameter of 33 inches, significant cost savings are achieved from the implementation of the tensioning system due to the elimination of the elaborate shaft and arm mechanism shown in FIG. 3.

[0028] A two-roller arrangement used on one side can be used to either provide better belt contact and reduce the chance of belt slippage, or to reduce belt tension. The contact area is increased from approximately 120 degrees to 210 degrees of roller circumference angle over the existing three-roller design. The reduced need for belt tension can allow for improved belt design, longer belt life, or a combination of both.

[0029] In one embodiment, the rotating discs 58, 60 are held coaxially with the rotating shaft assembly (outer shaft 54 ​​and inner shaft 56) by bearings on the periphery of the pairs of rotating discs.

[0030] In one embodiment, one of the rotating disks, for example disk 60, can be removed from both the tensioning roller 52 and the rotating shaft assembly (outer shaft 54 ​​and inner shaft 56) and moved apart so that the belt 18 can be removed from the tensioning rollers and the other rollers that define the belt loop without removing the belt rollers. The rotating shaft assemblies (outer shaft 54 ​​and inner shaft 56) function as part of the enclosure, and the rotating shaft assemblies are locked to both rotating disks during belt operation such that in the event of an explosion or other event inside the enclosure that generates a separating axial force on the rotating members, the rotating shaft assemblies hold the rotating disks together.

[0031] In one embodiment, two rollers in one set do not include a tension roller and two rollers in the other set do include a tension roller, and the drive rollers on the two-roller side are operated with a motor torque applied substantially more than the drive rollers on the three-roller side such that the motor torque applied on each roller is approximately proportional to the roller circumference when in intimate contact with the belt.

[0032] In one embodiment, the outer end of the inner shaft 56 is held coaxially with the closer end of the outer shaft 54 ​​by a bearing structure capable of resisting radial loads. The bearing structure consists of three or more cam followers.

[0033] For food / feed applications using nitrogen purge for oxygen inhibition, the tensioned system consumes significantly less nitrogen because the gap between the drive box wall and the rotating disk forms the main inflow of gas into the drive box, and the embodiment shown only needs to fill these gaps with nitrogen on one drive box instead of two. Despite the larger rotating disks used on the tensioned system, it is expected that an approximately 15% reduction in N2 demand will be achieved.

[0034] The volume of the drive box on the 2-roller side is reduced compared to existing 3-roller designs, which reduces the volume of air that needs to be vented in case of an internal explosion of a combustible dust / gas mixture. This is beneficial for food / feed applications where one output stream is expected to present a higher explosion risk than the other, in which case the higher risk output product may be sent to the 2-roller side.

[0035] When a tensioning roller in a belt loop is moved to create tension in the belt, it is important that the forces from the belt do not cause a deflection in the axial alignment of the tensioning roller relative to the belt loop. To accomplish this, the ends of the tensioning roller should ideally be held with a mechanism that causes the deflection on both roller ends to be the same due to the forces from the belt. The tensioning system embodiments disclosed herein solve this problem by using a compound shaft structure that allows for the use of actuation from one side of the tensioning roller while maintaining equal deflection of both tensioning roller ends.

[0036] In other embodiments, instead of containing two rotating disks, the mechanism can have two arms mounted on the outer rotating shaft. Each arm is connected to one end of the tensioning roller such that both arms undergo the same angular deflection defined by the plane passing through the center of the tensioning roller at the end of the arm and the axis of the outer rotating shaft under equal load from the tensioning roller with respect to the inner shaft. The outer rotating shaft is held by bearings on both ends that constrain lateral movement but allow the outer rotating shaft to rotate on its axis. In some embodiments, one arm can be removed from the tensioning roller so that the continuous belt can be removed from the tensioning roller without removing the tensioning roller.

[0037] Thus, having described certain embodiments of a belt separator system with a tensioning system, a method of operating the same, and a method of facilitating the operational life of the belt separator system, various alterations, modifications, and improvements will be apparent to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the present application. Accordingly, the foregoing description is by way of example only and is not intended to be limiting. The present application is limited only as defined by the following claims and equivalents thereto.

Claims

1. A tensioning mechanism for tensioning an endless belt, the tensioning mechanism comprising: A tension roller configured to apply tension to the belt; a pair of rotating disks coupled to the tension roller at each end of the tension roller, the pair of rotating disks being configured to apply tension to the belt by moving the tension roller; a rotating shaft assembly including an inner shaft, the rotating shaft assembly coupled to the pair of rotating disks, the rotating shaft assembly configured such that both rotating disks of the pair of rotating disks undergo substantially the same angular deflection relative to an outer end of the inner shaft when each disk exerts an equal amount of torque on the rotating shaft assembly relative to an opposing torque exerted by an actuator coupled to the inner shaft; Equipped with A tensioning mechanism, wherein the inner shaft is coupled to a hollow outer shaft, the hollow outer shaft being sized to receive the inner shaft with the inner shaft and the hollow outer shaft each being coupled to the pair of rotating disks.

2. 2. The tensioning mechanism of claim 1, wherein the pair of rotating disks are held coaxially with the rotating shaft assembly by bearings on the peripheries of the pair of rotating disks.

3. 2. The tensioning mechanism of claim 1, wherein one of the pair of rotating disks is configured to be removed from both the tensioning roller and the rotating shaft assembly and is configured to be moved apart such that the belt can be removed from the belt roller without removing the tensioning roller and a belt roller that defines a belt loop.

4. The pair of rotating disks function as part of an enclosure and are adapted to be coupled to the rotating shaft assembly such that the rotating shaft assembly holds the pair of rotating disks together in the event of an explosion inside the enclosure or other event that creates a separating axial force on the pair of rotating disks and the rotating shaft assembly.

4. The tensioning mechanism of claim 3, wherein a rotating shaft assembly is engaged with said pair of rotating disks during belt movement.

5. 2. The tensioning mechanism of claim 1, wherein the tensioning mechanism is included within a belt separator system comprising a first set of two rollers at a first end of the belt separator system and a second set of two rollers at a second end of the belt separator system, the first set of two rollers not including tensioning rollers and the second set of two rollers including tensioning rollers.

6. 6. The tensioning mechanism of claim 5, wherein the drive rollers on the first end are operated with a motor torque applied substantially greater than the drive rollers on the second end such that the motor torque applied on each roller is approximately proportional to the roller circumference when in intimate contact with the belt.

7. The tensioning mechanism of claim 1 , wherein the inner shaft is rotated by the actuator.

8. 2. The tensioning mechanism of claim 1, wherein the outer end of the inner shaft is held coaxially with the proximal end of the hollow outer shaft by a bearing structure capable of resisting radial loads.

9. 9. The tensioning mechanism of claim 8, wherein the bearing structure comprises three or more cam followers.

10. 2. The tensioning mechanism of claim 1, wherein instead of containing two rotating disks, the mechanism has two arms mounted on the hollow outer shaft, each arm connected to one end of the tensioning roller such that both arms undergo the same angular deflection defined by a plane passing through the center of the tensioning roller at the end of the arm and the axis of the hollow outer shaft under equal load from the tensioning roller on the inner shaft, the hollow outer shaft being held by bearings on both ends that constrain lateral movement but allow rotation of the hollow outer shaft on its axis.

11. 11. The tensioning mechanism of claim 10, wherein one arm is removable from the tensioning roller such that the belt can be removed from the tensioning roller without removing the tensioning roller.

12. 1. A belt separator system, comprising: a first electrode and a second electrode arranged on opposite sides of a longitudinal centerline, the first electrode and the second electrode configured to provide an electric field between the first electrode and the second electrode; a first set of rollers disposed at a first end of the system; a second set of rollers disposed at a second end of the system; and a continuous belt disposed between the first electrode and the second electrode, the continuous belt being supported by the first set of rollers and the second set of rollers; a separation zone defined by the continuous belt, the separation zone being between the continuous belts; a tensioning mechanism for tensioning the continuous belt; Equipped with The tensioning mechanism includes: a tension roller configured to apply tension to the continuous belt; a pair of rotating disks coupled to the tension roller at each end of the tension roller, the pair of rotating disks configured to apply tension to the continuous belt by moving the tension roller; a rotating shaft assembly including an inner shaft, the rotating shaft assembly coupled to the pair of rotating disks, the rotating shaft assembly configured such that both rotating disks of the pair of rotating disks undergo substantially the same angular deflection relative to an outer end of the inner shaft when each disk exerts an equal amount of torque on the rotating shaft assembly relative to an opposing torque exerted by an actuator coupled to the inner shaft; Including, the inner shaft is coupled to an outer shaft, the outer shaft being sized to receive the inner shaft with the inner shaft and the outer shaft each being coupled to the pair of rotating disks.

13. 13. The belt separator system of claim 12, wherein the pair of rotating disks are held coaxially with the rotating shaft assembly by bearings on peripheries of the pair of rotating disks.

14. 13. The belt separator system of claim 12, wherein one rotating disk of the pair of rotating disks is configured to be removed from both the tensioning roller and the rotating shaft assembly and can be moved apart such that the continuous belt can be removed from the tensioning roller and the first and second sets of rollers defining a belt loop without removing the rollers.

15. 15. The belt separator system of claim 14, wherein the pair of rotating disks act as part of an enclosure and the rotating shaft assembly is locked to the pair of rotating disks during operation such that the rotating shaft assembly holds the pair of rotating disks together in the event of an explosion inside the enclosure or other event that creates a separating axial force on the pair of rotating disks and the rotating shaft assembly.

16. 13. The belt separator system of claim 12, wherein the first set of two rollers does not include a tension roller and the second set of two rollers includes a tension roller.

17. 17. The belt separator system of claim 16, wherein the drive rollers on the first end are operated with a motor torque applied substantially greater than the drive rollers on the second end such that the motor torque applied on each roller is approximately proportional to the roller circumference in intimate contact with the continuous belt.

18. The belt separator system of claim 12 , wherein the inner shaft is rotated by the actuator.

19. 13. The belt separator system of claim 12, wherein the outer end of the inner shaft is held coaxially with a proximal end of the outer shaft by a bearing structure capable of resisting radial loads.

20. 20. The belt separator system of claim 19, wherein the bearing structure comprises three or more cam followers.

21. 13. A method for fluidizing a particulate mixture in a belt separator system according to claim 12, said method comprising: introducing said particulate mixture into a feed port of said belt separator system; providing a decoupling influence to at least one of the first electrode and the second electrode; separating different components of the particle mixture according to their relative influence on the separating influence in the direction of the separating influence; mechanically displacing the different components of the particle mixture laterally relative to the separating influence; removing the separated components from the separation chamber; A method comprising:

22. 22. The method of claim 21, further comprising: maintaining the pair of rotating disks coaxially with the rotating shaft assembly by bearings on peripheries of the pair of rotating disks.

23. 23. The method of claim 22, further comprising removing one rotating disk of the pair of rotating disks from both the tensioning roller and the rotating shaft assembly, and moving the rotating disk away such that the continuous belt can be removed from the tensioning roller and the first and second sets of rollers defining a belt loop without removing the rollers.

24. The pair of rotating disks function as part of an enclosure; 24. The method of claim 23, further comprising locking the rotating shaft assembly to the pair of rotating disks during operation such that the rotating shaft assembly holds the pair of rotating disks together in the event of an explosion inside the enclosure or other event that creates a separating axial force on the pair of rotating disks and the rotating shaft assembly.

25. The method of claim 21 , further comprising providing the second set of two rollers with the tension roller.

26. 26. The method of claim 25, further comprising operating the drive rollers on the first end with a motor torque applied substantially greater than the drive rollers on the second end such that the motor torque applied on each roller is approximately proportional to the roller circumference in intimate contact with the continuous belt.

27. 22. The method of claim 21, further comprising holding the outer end of the inner shaft coaxially with a proximal end of the outer shaft by a bearing structure capable of resisting radial loads.

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