TENSIONING MECHANISM FOR BELT-TYPE TRIBOELECTRIC SEPARATOR DEVICES

Abstract

An improved belt separator system and an improved method for separating particle mixtures based on triboelectric particle separation are disclosed. The separator system includes a tensioning system containing a tension roller and a two-part rotating shaft assembly.

Description

This application claims the benefit of priority to United States Provisional Patent Application No. 62 / 831,329, filed on April 9, 2019, entitled “TENSIONING MECHANISM FOR BELT-TYPE TRIBOELECTRIC SEPARATOR DEVICES” which is incorporated herein by reference in its entirety for all purposes. FIELD OF INVENTION The present invention relates to a tensioning mechanism for a belt-type triboelectric separator system, for example, to provide for the electrical charging and subsequent triboelectric separation of particles with the belt separation apparatus. Analysis of the related technique Belt separator systems (BSS) are used to separate the constituents of particle mixtures based on the charge of the different constituents by surface contact (i.e., the triboelectric effect). Figure 1 shows a belt separator system as disclosed in U.S. Common Property Patents 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 in a longitudinal direction to define a process chamber 14 having a longitudinal centerline 16, and a belt 18 traveling in the longitudinal direction between the spaced electrodes, parallel to the longitudinal centerline. The belt 18 forms a continuous loop that is driven by a pair of end rollers 20, 22. A particle mixture is loaded onto the belt 18 in a feed area 11 between the electrodes 10.Belt 18 includes countercurrent belt segments 18A and 18B that move in opposite directions to transport the constituents of the particle mixture along the lengths of electrodes 10 and 12. The only moving part of the BSS is belt 18, which moves at high speed, for example, about 64.3738 km / h (40 miles per hour), in an extremely abrasive environment. The two belt segments 18A and 18B move in opposite directions, parallel to the centerline 16. In one mode, a negative voltage is applied to the upper electrodes 10 and a positive voltage to the lower electrode 12, causing positively charged feed particles to be attracted to the negative upper electrodes and negatively charged feed particles to be attracted in the opposite direction. As the upper belt segment 18A moves to the right and the lower belt segment 18B moves to the left, the material exiting the process chamber 14 on the right will be enriched. WUUa / ZUZl / U1 ZύύZ with positively charged particles while the material coming out from the left will be negatively enriched, charged particles. 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 collisions, particle belt and particle walls in the strong electric field, together with the movement of the belt 18, will result in one output stream being enriched in carbon and the other output stream being enriched in silica compared to the original feed. In one known embodiment, the belt 18 shown in Figure 1 has four rollers: two drive rollers 20 and 22 and two idler rollers 20A and 22A. For this basic configuration, belt tension is achieved by linear actuator(s) connected to the drive rollers, which move the drive roller along the same axis as the belt's movement. In another known embodiment, two additional idler rollers, called tensioner rollers, can be moved to maintain tension in the belt loop even with substantial belt elongation. Figure 2 illustrates the belt 18 and the tensioner rollers 24 and 26. The two additional tensioner rollers 24 and 26 are the upper rollers, and the tensioning mechanism moves these two rollers in a rotary motion to tension the belt 18. Belt 18 requires constant tension during material processing to prevent slippage on the two drive rollers 20 and 22, so pre-tensioning is applied. Drag forces generated on belt 18 (particularly within the processing chamber 14) add additional tension to the belt in certain segments of the belt loop. Current production belts are made of a plastic material, which experiences substantial elongation over several hundred hours of operation due to belt tension. The current system can accommodate approximately 50.8 cm (20 in) of belt elongation on each side of the belt, for a total elongation of approximately 101.6 cm (40 in). With further reference to Figure 3, in a known embodiment, each tension roller 24, 26 is mounted on two rotating discs, the near-side rotating disc being designated 28 in Figure 3. This currently requires an elaborate tensioning mechanism to ensure that both rotating discs rotate by the same amount to prevent misalignment of the tension roller with respect to the belt 18. If the tension rollers become misaligned, the belt 18 will not travel correctly and may strike a side wall of the process chamber 14. This tensioning mechanism for coupling the movement of the rotating disc is shown in Figure 3. iviA / a / ¿u¿ i / ui ¿ ύύζ BRIEF DESCRIPTION OF THE INVENTION The aspects and modalities are directed to a system to supply a tensioning mechanism for a triboelectric belt-type separator system. One aspect of this disclosure relates to a tensioning mechanism for tensioning an endless belt. In one embodiment, the tensioning mechanism comprises a tensioning roller configured to apply tension to a belt, a pair of rotating discs coupled to the tensioning roller at the respective ends of the tensioning roller, the pair of rotating discs being configured to move the tensioning roller to apply tension to the belt, and a rotating shaft assembly coupled to the pair of rotating discs. The rotating shaft assembly includes an inner shaft coupled to an outer shaft. The inner shaft is rotated by an actuator. The outer shaft is dimensioned to receive the inner shaft inside and is coupled to the pair of rotating discs.The rotating shaft assembly is configured so that both rotating disks of the rotating disk pair experience approximately the same angular deflection about the outer end of the inner shaft when each disk exerts the same amount of torque on the rotating shaft assembly against the opposing torque exerted by an actuator on the inner shaft. The tensioning mechanism may also include securing the pair of coaxial rotating discs to the rotating shaft assembly by means of bearings at the perimeters of the rotating disc pair. One rotating disc of the rotating disc pair may be configured to separate from both the tensioner roller and the rotating shaft assembly, and to move away so that the belt can be removed from the tensioner roller and other rollers, defining a belt loop without removing the rollers from the belt. The rotating disc pair may serve as part of an enclosure. The rotating shaft assembly may be locked to the rotating disc pair during belt operation, so that the rotating shaft assembly holds the rotating disc pair together in the event of an explosion within the enclosure or another event that generates axial separation forces on the rotating members.The tensioning mechanism may be 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, wherein the first set of two rollers does not include a tensioning roller and the second set of two rollers includes a tensioning roller. A driving roller on the first side may operate with a substantially higher applied torque than a driving roller on the second side, such that the applied torque on each roller is approximately proportional to the length of the circumference of the roller in firm contact with the belt. The outer end of the inner shaft may be kept coaxial to the nearest end of the outer shaft by a support structure capable of resisting radial loads. The support structure may consist of three or more cam followers.In another embodiment, instead of containing two rotating discs, the mechanism may have two arms mounted on the outer rotating shaft, with each arm connected to one end of the tension roller so that both arms experience the same angular deflection defined by a plane through the center of the tension roller at the arm end and the axis of the outer rotating shaft under equal loads. The tension roller, relative to the inner shaft, is supported by bearings at both ends, which restrict lateral movement but allow rotation of the outer rotating shaft about its axis. One arm can be separated from the tension roller so that the continuous belt can be removed from the tension roller without removing the tension roller itself. Another aspect of the present disclosure is directed to a belt separator system comprising a first electrode and a second electrode disposed 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 set of rollers and the 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 tensioner roller configured to apply tension to a continuous belt and a pair of rotating discs coupled to the tensioner roller at its respective ends. The pair of rotating discs is configured to move the tensioner roller to apply tension to the continuous belt. The tensioning mechanism further includes a rotating shaft assembly coupled to the pair of rotating discs. The rotating shaft assembly includes an inner shaft coupled to an outer shaft. The inner shaft is rotated by an actuator. The outer shaft is dimensioned to receive the inner shaft and is coupled to the pair of rotating discs.The rotating shaft assembly is configured so that both rotating disks of the rotating disk pair experience approximately the same angular deflection about the outer end of the inner shaft when each disk exerts the same amount of torque on the rotating shaft assembly against the opposing torque exerted by an actuator on the inner shaft. The belt separator system may also include securing the pair of coaxial rotating discs to the rotating shaft assembly by means of bearings at the perimeters of the rotating disc pair. One rotating disc of the rotating disc pair may be separated from both the tensioner roller and the rotating shaft assembly, and moved away so that the continuous belt can be removed from the tensioner roller and the first and second sets of rollers that define a belt loop without removing the rollers. The rotating disc pair may serve as part of an enclosure. The rotating shaft assembly may be locked to the rotating disc pair during operation, so that the rotating shaft assembly holds the rotating disc pair together in the event of an explosion within the enclosure or other event that generates axial separation forces on the rotating members. The first set of two rollers does not include one roller. The first set of two rollers includes a tension roller, and the second set includes a tension roller. A drive roller on the first side can operate with a substantially higher applied torque than a drive roller on the second side, such that the applied torque on each roller is approximately proportional to the length of the circumference of the roller in firm contact with the continuous belt. The outer end of the inner shaft can be kept coaxial to the nearest end of the outer shaft by a support structure capable of resisting radial loads. The support structure can consist of three or more cam followers. Another aspect of this disclosure relates to a method for fluidizing a particle mixture within a belt separator system. In one embodiment, the method comprises introducing the particle mixture into a feed port of the belt separator system. The system comprises 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 and second electrodes, a first set of rollers arranged at a first end of the system, a second set of rollers arranged at a second end of the system, a continuous belt disposed between the first and second electrodes and supported by the first and second sets 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 tension roller configured to apply tension to a continuous belt and a pair of rotating discs coupled to the tension roller at its respective ends. The pair of rotating discs is configured to move the tension roller to apply tension to the continuous belt. The tensioning mechanism further includes a rotary shaft assembly coupled to the pair of rotating discs. The rotary shaft assembly includes an inner shaft coupled to an outer shaft. The inner shaft is rotated by an actuator. The outer shaft is sized to receive the inner shaft and is coupled to the pair of rotating discs.The rotating shaft assembly is configured such that both rotating discs of the rotating disc pair experience approximately the same angular deflection with respect to the outer end of the inner shaft when each disc exerts the same amount of torque on the rotating shaft assembly against the opposing torque exerted by an actuator on the inner shaft. The method further comprises providing a separation influence to at least one of the first and second electrodes; separating the different components of the particle mixture in the direction of the separation influence according to their relative influence; mechanically moving the different components of the particle mixture transversely to the separation influence; and removing the separated components from said separation chamber. The method may further include securing the pair of coaxial rotating discs to the rotating shaft assembly by means of bearings at the perimeters of the rotating disc pair. The method may further include separating one rotating disc from the pair of rotating discs from both the tensioner roller and the rotating shaft assembly, and moving the rotating disc away so that the continuous belt can be removed from the tensioner roller and the first and second sets of rollers that define a belt loop without removing the rollers. The method may further include locking the rotating shaft assembly to the pair of rotating discs during operation, so that the rotating shaft assembly holds the pair of rotating discs together in the event of an explosion within the enclosure or other event that generates axial separation forces on the rotating members. The method may further include providing the second set of two rollers with the tensioner roller.The method may further include operating a drive roller on the first side with a substantially greater applied torque than a drive roller on the second side, such that the applied torque on each roller is approximately proportional to the circumference of the roller in firm contact with the continuous belt. The method may further include supporting the outer end of the inner shaft coaxial to the nearest end of the outer shaft by means of a support structure capable of resisting radial loads. BRIEF DESCRIPTION OF THE DRAWINGS Several 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 illustration and further understanding of the various aspects and embodiments and are incorporated into and form part of this specification, but are not intended to define the limits of the invention. Where technical features in the figures, the detailed description, or any claim are followed by reference signs, the reference signs have been included solely to enhance the intelligibility of the figures and the description. In the figures, each identical or nearly identical component illustrated in several figures is represented by a similar number. For clarity, not all components may be labeled in all figures. In the figures: Figure 1 is a diagram of an example of a known belt separator system (BSS); Figure 2 is a side elevation view of the tensioning system of a known BSS; Figure 3 is a perspective view of an actuator system for the tension system shown in Figure 2; Figure 4 is a cross-sectional view of a tension system of one modality of the present disclosure; Figure 5 is a perspective view of components of the tension system shown in Figure 4. WUUa / ZUZl / U1 ZÓÓZ Figure 6 is another perspective view of the tension system components shown in Figure 4; and Figure 7 is another perspective view of the tension system components shown in Figure 4. DETAILED DESCRIPTION The systems and methods provided herein are intended as improvements to belt separator systems and their operation. Specifically, the systems and methods described herein can enhance or augment belt separator systems through an improved tensioning system. This can lead to optimized system operation and reduce operating costs and downtime due to equipment replacement. It should be noted that the modalities of the methods and apparatus discussed here are not limited in their application to the construction details and component arrangement set forth in the following description or illustrated in the accompanying drawings. The methods, systems, and apparatus are capable of implementation in other modalities and of being put into practice or carried out in various ways. Examples of specific implementations are provided here for illustrative purposes only and are not intended to be limiting. Furthermore, the phraseology and terminology used in this document are for descriptive purposes and should not be considered limiting. The use herein of terms including, comprising, having, containing, implying, and variations thereof is intended to encompass the elements listed below and their equivalents, as well as additional elements.References to "or" may be interpreted inclusively so that any term described using "or" may indicate any one, more than one, or all of the terms described. Any reference to modalities, elements, or acts of the systems and methods mentioned herein in the singular may also encompass modalities that include a plurality of these elements, and any reference in the plural to any modality, element, or act herein may also encompass modalities that include only a single element. Any reference to front and back, left and right, top and bottom, upper and lower, and vertical and horizontal is intended for convenience of description, not to limit the systems and methods herein or their components to any positional or spatial orientation. This disclosure relates to an improved tensioning mechanism for a triboelectric belt-type separator system, for example, in a countercurrent triboelectric belt-type separator system. As noted above, Figure 1 shows the BSS mode with a continuous countercurrent belt 18 moving between two parallel longitudinal flat electrodes 10, 12. The belts can be made of various materials. For example, woven belts or extruded belts can be used. A current design of an ultra-high-molecular-weight polyethylene (UHMWPE) belt features straight, smooth edge strands in the machine direction that are thicker than the machine-direction or cross-direction strands on the inside of the belt. These wider edge strands (20–30 mm) support higher tensile loads, provide dimensional stability, and reduce the incidence of belt failure due to edge abrasion. These UHMWPE sheet belts have demonstrated a significantly longer lifespan than extruded belts. In certain applications, such as separating unburned carbon from fly ash produced during coal combustion, these UHMWPE belts have been tested and shown to have a maximum service life of up to 1,950 hours before failure. The embodiments of this disclosure relate to a tensioning system that replaces the external shaft and actuator hardware shown in Figure 3, and instead connects the two rotating disks with a coaxial internal shaft. Due to the high torque and shaft length, a single regular shaft of any reasonable dimension (whether hollow or solid) would twist under the torque load and cause significant deflections and misalignment of the tension roller if a single actuator were used at one end of the shaft. The embodiments of this disclosure solve this problem by using a hollow shaft with a secondary internal shaft. Referring to Figure 4, the tensioning mechanism, generally designated 50, includes a tension roller 52 coupled to a rotating shaft assembly comprising a hollow outer shaft 54 ​​and an inner shaft 56. The tension roller 52 and the rotating shaft assembly are coupled to a pair of rotating discs 58, 60 mounted on the outer ends of the tension roller. Specifically, the outer shaft 54 ​​and the inner shaft 56 of the rotating shaft assembly are mounted along a centerline of the rotating discs 58, 60, with the tension roller 52 mounted off-axis with respect to the rotating discs. As shown, the inner shaft 56 can rotate independently of the outer shaft 54 ​​such that the torsion of the inner shaft does not cause a difference in the angular deflection of the two rotating discs 58, 60 that carry the tension roller 52. The hollow outer shaft 54 ​​will also experience torsional deflection, but a cross-section of the outer shaft and the connection to the inner shaft 56 is dimensioned and positioned so that both rotating discs 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 (on the right in Figure 4) to be rotated by a single actuator. In one embodiment, with reference to Figure 5, an air piston 62 is provided to actuate the rotating disc 58 to drive the rotation of the other rotating disc via the outer and inner shafts 54, 56.Any type of drive mechanism may be provided in place of the air piston 62, for example, an electric screw drive or some other type of drive. Since the two rotating discs 58, 60 have the same rotational rigidity with respect to the drive shaft (i.e., the rotating shaft assembly), the tension roller 52 will not become misaligned under a belt load well centered on the tension roller. The modalities of the tensioning system 50 of this disclosure allow a desired 101.6 cm (40 in) of belt elongation to be accommodated with a single tensioning mechanism. Thus, instead of six rollers, the belt loop can use only five. One side of the tensioning system 50 includes two rollers as shown on the left in Figure 1, e.g., rollers 20A and 20B, while the other side of the tensioning system includes three rollers as shown in Figure 2, e.g., rollers 22, 22A, and 26. Significant cost savings are therefore achieved with the implementation of the tensioning system due to the elimination of the elaborate shaft and arm mechanism shown in Figure 3, even though the rotating disc on the three-roller side has been enlarged from approximately 50.8 cm (20 in) in diameter to 83.82 cm (33 in) in diameter. The two-roller arrangement used on one side provides better belt contact and can be used to reduce the possibility of belt slippage or to reduce belt tension. The contact area increases from approximately 120 degrees to 210 degrees of roller circumference angle compared to the existing three-roller design. The reduced belt tension requirement can allow for improved belt designs, longer belt life, or a combination of both. In one embodiment, the rotating discs 58, 60 are held coaxial to the rotating shaft assembly (outer shaft 54 ​​and inner shaft 56) by means of bearings on the perimeters of the pair of rotating discs. In one embodiment, one of the rotating discs, for example, disc 60, can be separated from both the tensioner roller 52 and the rotating shaft assembly (outer shaft 54 ​​and inner shaft 56), and moved away so that the belt 18 can be removed from the tensioner roller and other rollers defining a belt loop without removing the rollers from the belt. The rotating shaft assembly (outer shaft 54 ​​and inner shaft 56) serves as part of an enclosure, with the rotating shaft assembly locked to both rotating discs during belt operation, so that the rotating shaft assembly holds the rotating discs together in the event of an explosion within the enclosure or other event that generates axial separation forces on the rotating members. In one embodiment, one set of two rollers does not include a tension roller, while the other set of two rollers includes a tension roller. A drive roller on one side of a two-roller assembly is operated with a substantially higher applied torque than a drive roller on one side of a three-roller assembly, such that the torque applied to each roller is approximately proportional to the length of the circumference of the roller in firm contact with the belt. In one embodiment, the outer end of the inner shaft 56 is held coaxial to the nearest end of the outer shaft 54 ​​by a support structure capable of resisting radial loads. The support structure consists of three or more cam followers. For food / food processing applications that use nitrogen purging for oxygen suppression, the tensioning system consumes significantly less nitrogen. This is because the spaces between the drive housing walls and the rotating discs form the main gas entry point to the drive housings, and the embodiment shown only needs to flood these spaces with nitrogen in one drive housing instead of two. Despite the larger rotating discs used in the tensioning system, a reduction of approximately 15% in N2 demand is expected. The transmission case volume on the two-roller side is reduced compared to the existing three-roller design, thus reducing the volume of air that must be vented in the event of an internal explosion of combustible dust / gas mixtures. This is beneficial for food / consumer applications where one outlet stream is expected to present a higher explosion risk than the other, in which case the higher-risk outlet stream would be directed to the two-roller side. When a tension roller is a moving belt loop that generates belt tension, it is important that the belt forces do not cause deflections in the axial alignment of the tension roller with respect to the belt loop. To achieve this, ideally the ends of the tension roller should be secured with a mechanism that deflects equally at both ends due to the belt forces. The tensioning system modalities described here solve this problem by using a composite shaft structure, which allows the drive to be used from one side of the tension roller while maintaining the same deflection at both ends. In other embodiments, instead of containing two rotating discs, the mechanism may have two arms mounted on the outer rotating shaft. Each arm is connected to one end of the tension roller so that both arms experience the same angular deflection defined by a plane passing through the center of the tension roller at the arm's end, and the axis of the outer rotating shaft is under equal loads from the tension roller relative to the inner shaft. The outer rotating shaft is supported by bearings at both ends, which restrict lateral movement but allow rotation of the outer rotating shaft about its axis. In one embodiment, one arm can be separated from the tension roller so that the continuous belt can be removed from the tension roller without removing the tension roller itself. Having thus described certain embodiments of a belt separator system comprising a tensioning system, methods for operating the same, and methods for extending the service life of the belt separator system, various alterations, modifications, and improvements will be evident to those skilled in the art. It is intended that such alterations, variations, and improvements are within the spirit and scope of the application. Accordingly, the foregoing description is by way of example and is not intended to be limiting. The application is limited only as defined in the following claims and their equivalents.

Claims

1. A tensioning mechanism for tensioning an endless belt, the tensioning mechanism comprising: a tension roller configured to apply tension to a belt; a pair of rotating discs coupled to the tension roller at the respective ends of the tension roller, the pair of rotating discs being configured to move the tension roller to apply tension to the belt;and a rotating shaft assembly coupled to the pair of rotating discs, the rotating shaft assembly includes an inner shaft coupled to an outer shaft, the inner shaft being rotated by an actuator, the outer shaft being sized to receive the inner shaft thereon and coupled to the pair of rotating discs, the rotating shaft assembly being configured so that both rotating discs of the pair of rotating discs experience approximately the same relative angular deflection with the outer end of the inner shaft when each disc exerts the same amount of torque on the rotating shaft assembly against the opposing torque exerted by an actuator on the inner shaft.

2. The tensioning mechanism according to claim 1, wherein the pair of rotating discs is held coaxial to the rotating shaft assembly by means of bearings on the perimeters of the pair of rotating discs.

3. The tensioning mechanism according to claim 1, wherein a rotating disc of the pair of rotating discs is configured to separate from both the tensioning roller and the rotating shaft assembly, and to move away so that the belt can be removed from the tensioning roller and other rollers defining a belt loop without removing the rollers from the belt.

4. The tensioning mechanism according to claim 3, wherein the pair of rotating discs serves as part of an enclosure, wherein the rotating shaft assembly is locked to the pair of rotating discs during belt operation, such that the rotating shaft assembly keeps the pair of rotating discs together in the event of an explosion within the enclosure or other event that generates axial separation forces on the rotating members.

5. The tensioning mechanism according to 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, wherein the first set of two rollers does not include a tensioning roller and the second set of two rollers includes a tensioning roller.

6. The tensioning mechanism according to claim 5, wherein a drive roller on the first side operates with a substantially greater applied motor torque than a drive roller on the second side such that the motor torque applied to each roller is approximately proportional to the length of the circumference of the roller in firm contact with the belt.

7. The tensioning mechanism according to claim 1, wherein the outer end of the inner shaft is held coaxial to the nearest end of the outer shaft by means of a support structure capable of resisting radial loads.

8. The tensioning mechanism according to claim 7, wherein the support structure consists of three or more cam followers.

9. The tensioning mechanism according to claim 1, wherein instead of containing two rotating discs, the mechanism has two arms mounted on the outer rotating shaft, each arm connected to one end of the tension roller so that both arms experience the same angular deflection defined by a plane through the center of the tension roller at the arm end and the axis of the outer rotating shaft under equal loads of the tension roller relative to the inner shaft, the outer rotating shaft being held by bearings at both ends, which restrict lateral movement but allow rotation of the outer rotating shaft about its axis.

10. The tensioning mechanism according to claim 9, wherein an arm can be separated from the tensioner roller so that the continuous belt can be removed from the tensioner roller without removing the tensioner roller.

11. A belt separator system, comprising: 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 and second electrodes; a first set of rollers arranged at a first end of the system; a second set of rollers arranged at a second end of the system; a continuous belt disposed between the first and second electrodes and supported by the first set of rollers and the 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 including a tension roller configured to apply tension to the continuous belt, a pair of rotating discs coupled to the tension roller at the respective ends of the tension roller, the pair of rotating discs being configured to move the tension roller to apply tension to the belt,and a rotating shaft assembly coupled to the pair of rotating discs, the rotating shaft assembly includes an inner shaft coupled to an outer shaft, the inner shaft being rotated by an actuator, the outer shaft being sized to receive the inner shaft thereon and coupled to the pair of rotating discs, the rotating shaft assembly being configured such that both rotating discs of the pair of rotating discs experience approximately the same relative angular deflection with the outer end of the inner shaft when each disc exerts the same amount of torque on the rotating shaft assembly against the opposing torque exerted by an actuator on the inner shaft.

12. The belt separator system according to claim 11, wherein the pair of rotating discs is held coaxial to the rotating shaft assembly by bearings on the perimeters of the pair of rotating discs.

13. The belt separator system according to claim 11, wherein a rotating disc of the pair of rotating discs can be separated from both the tensioner roller and the rotating shaft assembly, and moved away so that the continuous belt can be removed from the tensioner roller and the first and second sets of rollers defining a belt loop without removing the rollers.

14. The belt separator system according to claim 9, characterized in that the pair of rotating discs serves as part of an enclosure, wherein the rotating shaft assembly is locked to the pair of rotating discs during operation, so that the rotating shaft assembly keeps the pair of rotating discs together in the event of an explosion within the enclosure or other event that generates axial separation forces on the rotating members.

15. The belt separator system according to claim 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.

16. The belt separator system according to claim 15, wherein a drive roller on the first side is operated at a substantially greater applied torque than a drive roller on the second side such that the applied torque on each roller is approximately proportional to the length of the circumference of the roller in firm contact with the continuous belt.

17. The belt separator system according to claim 11, wherein the outer end of the inner shaft is held coaxial to the nearest end of the outer shaft by means of a support structure capable of resisting radial loads.

18. The belt separator system according to claim 17, wherein the support structure consists of three or more cam followers.

19. A method for fluidizing a particle mixture within a belt separator system, the method comprising: introducing the particle mixture into a port of the belt separator system, the system comprising: a first electrode and a second electrode disposed 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 set of rollers and the 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 including a tension roller configured to apply tension to the continuous belt,a pair of rotating discs coupled to the tensioner roller at the respective ends of the tensioner roller, the pair of rotating discs being configured to move the tensioner roller to apply tension to the belt, and a rotating shaft assembly coupled to the pair of rotating discs, the rotating shaft assembly including an inner shaft coupled to an outer shaft, the inner shaft being rotated by an actuator, the outer shaft being sized to receive the inner shaft thereon and coupled to the pair of rotating discs,The rotating shaft assembly is configured such that both rotating discs of the rotating disc pair experience approximately the same relative angular deflection with respect to the outer end of the inner shaft when each disc exerts the same amount of torque on the rotating shaft assembly against the opposing torque exerted by an actuator on the inner shaft; providing a separation influence to at least one of the first and second electrodes; separating different components of the particle mixture in the direction of the separation influence according to their relative influenceability with the separation influence; mechanically moving the different components of the particle mixture transversely to the separation influence; and removing the separated components from said separation chamber.

20. The method according to claim 19, further comprising maintaining the pair of coaxial rotating discs to the rotating shaft assembly by means of bearings on the perimeters of the pair of rotating discs.

21. The method according to claim 20, further comprising separating a rotating disc from the pair of rotating discs from both the tensioner roller and the rotating shaft assembly, and moving the rotating disc away so that the continuous belt can be removed from the tensioner roller and the first and second sets of rollers defining a belt loop without removing the rollers.

22. The method according to claim 21, further comprising locking the rotating shaft assembly to the pair of rotating discs during operation, so that the rotating shaft assembly keeps the pair of rotating discs together in the event of an explosion within the enclosure or other event that generates axial separation forces on the rotating members.

23. The method according to claim 19, further comprising providing the second set of two rollers with the tension roller.

24. The method according to claim 23, further comprising operating a drive roller on the first side with a substantially greater applied torque than a drive roller on the second side, such that the applied torque on each roller is approximately proportional to the length of the circumference of the roller in firm contact with the continuous belt.

25. The method according to claim 19, further comprising maintaining the outer end of the inner shaft coaxial to the nearest end of the outer shaft by means of a support structure capable of resisting radial loads.

26. A belt separator system including a tensioning mechanism as shown and described herein.

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