AU2008261618B2

AU2008261618B2 - On-line analyser

Info

Publication number: AU2008261618B2
Application number: AU2008261618A
Authority: AU
Inventors: Cheryl Su-Lean Lim; Stephen Rainey
Original assignee: Commonwealth Scientific and Industrial Research Organization CSIRO
Current assignee: Commonwealth Scientific and Industrial Research Organization CSIRO
Priority date: 2007-06-15
Filing date: 2008-06-13
Publication date: 2013-10-03
Anticipated expiration: 2028-06-13
Also published as: AU2008261618A1; ZA201000156B; WO2008151378A1

Abstract

The invention in a preferred embodiment is directed to an on-line analyser (10) comprising an upper L-shaped module (12) that connects to a lower L-shaped module (14). The modules (12) and (14) connect together to define a tunnel (16) through which material conducting means such as a conveyor belt (18) can pass. The modules (12) and (14) have cavities such as (24, 26, 28, 30) and (32) arranged to receive either a radiation source holder such as (34), a detector holder such as (36), or a blanking tube such as (39). The radiation source holder or rod (34) comprises a medium energy neutron source or alternatively a neutron generator or some other source of radiation which may not be neutrons.

Description

ON-LINE ANALYSER FIELD OF THE INVENTION The present invention relates broadly to an on-line analyser and relates particularly, although not exclusively, to an on-conveyor belt analyser for use in the mining, mineral 5 processing and energy industries. BACKGROUND OF THE INVENTION There is an increasing need in industry, arising from both economic and environmental considerations, to reduce costs and improve product quality through the use of automation. The use of on-line analysis instrumentation provides plant operators with a means for 10 continuous measurement and rapid response. This can result in better control of process efficiency, product quality and resource utilisation, all of which produce significant economic and environmental benefits. Rapid on-line measurement of bulk elemental composition is important in many industrial applications and can be achieved with highly penetrating neutron-gamma techniques. 15 SUMMARY OF THE INVENTION According to the present invention there is provided an on-line analyser comprising a pair of L shaped modules being arranged to connect to one another to together define a tunnel through which a conveyor belt passes, the L-shaped modules configured to be oriented transverse to the conveyor belt and located between conveyor belt idlers. 20 Typically the on-line analyser is arranged for elemental analysis of materials conducted through the tunnel by the conveyor belt. Preferably one of the L-shaped modules is an upper module resting on the other of the L shaped modules being a lower module. More preferably one leg of each of the L-shaped modules is oriented substantially upright and dimensioned to preset the height of the tunnel. 25 Still more preferably the other leg of each of the L-shaped modules is dimensioned to preset the width of the tunnel.

WO 2008/151378 PCT/AU2008/000850 Preferably one of the L-shaped modules defines a cavity for containing either a radiation source or a radiation detector. More preferably the cavity is located in either of the upper or the lower L-shaped modules. Still more preferably the cavity includes a passageway. Even still more preferably the cavity contains both a radiation source and a radiation 5 detector. Yet still more preferably both of the L-shaped modules define a cavity for containing either a radiation source or a radiation detector. Preferably the on-line analyser also comprises a shielding module located alongside the L-shaped modules. More preferably the shielding module is U-shaped. Even more preferably the U-shaped shielding module is one of two shielding modules located either 10 side of the L-shaped modules. Preferably one of the pair of L-shaped modules has alignment means configured to mate with corresponding alignment means of the other of the pair of L-shaped modules. Preferably the on-line analyser also comprises a radiation source holder being elongate and foldable along its length. More preferably the source holder is retractably received in 15 the passageway. Preferably the analyser further comprises a radiation source. More preferably the analyser further comprises a neutron source such as a radioisotope or a neutron generator such as a Deuterium-Tritium neutron generator. Even more preferably the radioisotope is contained by the radiation source holder. 20 Preferably the analyser is arranged to detect scattered or induced radiation from the material. More preferably the analyser is arranged to detect neutron-induced gamma rays. Even more preferably the analyser is arranged to detect gamma rays induced by one or more of neutron inelastic scattering, thermal neutron capture, delayed activation or nuclear particle reactions. 25 The on-line analyser may also comprise a support frame mounted to one of the L-shaped modules and including guide means for supporting the conveyor belt.

WO 2008/151378 PCT/AU2008/000850 3. BRIEF DESCRIPTION OF THE FIGURES In order to achieve a better understanding of the nature of the invention a preferred embodiment of an on-line belt analyser will now be described, by way of example only, with reference to the accompanying figures, in which: 5 Figure 1 is an exploded perspective view of a preferred embodiment of an on-line analyser; Figure 2 is an exploded perspective view of another embodiment of an on-line analyser, through which a conveyor belt passes. Figure 3 is a perspective view of yet another embodiment of an on-line analyser. 10 Figure 4 is a perspective view of connected L-shaped modules of the analyser of figure 3; Figure 5 is a perspective view of a lower module of the on-line analyser of figure 3; Figure 6 is a perspective view of a radiation source holder of the on-line analysers of figures 1, 2 and 3; Figure 7 is a perspective view of the radiation source holder of figure 6 in its folded 15 configuration; Figure 8 is a perspective view of a detection rod of the on-line analysers of figures 1, 2 and 3; and Figure 9 is a blanking tube of the on-line analyser of figure 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 20 A preferred embodiment of an on-line analyser according to the present invention is shown in figure 1 and generally designated by reference numeral 10. The analyser 10 comprises an upper L-shaped module 12 that connects to a lower L-shaped module 14. The modules 12 and 14 connect together to define a tunnel 16 through which material conducting means in the form of a conveyor belt (indicated by the numeral 18 in figure 3 25 which depicts another embodiment of an on-conveyor belt analyser where parts similar to parts of the embodiment of figure 1 are similarly numbered) can pass. The conveyor belt WO 2008/151378 PCT/AU2008/000850 4. may be replaced by a chute in some embodiments. The legs 20, 22 of each of the modules 12, 14 are orientated substantially upright and dimensioned to preset the height of the tunnel 16. The other legs 21 and 23 of the modules 12,14 are dimensioned to preset the width of the tunnel. The modules 12 and 14 have cavities which in this 5 embodiment include elongate passageways 24, 26, 28, 30 and 32 arranged to receive either a radiation source holder such as 34, a detector holder such as 36, or a blanking tube such as 39. A variable number of detectors and/or sources may be employed. In the preferred embodiment the radiation source holder or rod 34 comprises a medium energy neutron source such as the radio isotope 24 'Am-Be located adjacent one end of 10 the rod 34. Some embodiments, however, may include a neutron generator such as Deuterium-Tritium neutron generator or some other source of radiation which may not be neutrons. In this embodiment however, the emitted neutrons interact with the atomic nuclei of any matter (not shown) conveyed by the belt (indicated by reference numeral 18 in figure 3) through the analyser 10, resulting in the emission of gamma rays by the matter 15 of energy characteristic to the nucleus. Measurement of the gamma rays by a detector within the detector holder 36 enables determination of the matter's elemental composition. In the preferred embodiment the primary reaction types may be any one of neutron inelastic scattering, thermal neutron capture, delayed activation and particle reactions. In embodiments of an on-line analyser with a neutron source, promptly emitted gamma-rays 20 from neutron inelastic scattering and thermal neutron capture are preferred in most cases. However, the measurement of delayed activation gammas may be beneficial in some circumstances. In embodiments of an on-line analyser with a Deuterium-Tritium neutron generator, gamma rays from all four of the above mentioned reactions are expected. In most cases, the first three will be preferred, although in some cases, particle reactions 25 may be useful. As shown in figure 1, the preferred embodiment of the lower module 14 includes both the source holder 34 and the detection holder 36 located alongside one another in their respective passageways 28 and 26. The holders 34 and 36 at a distal end protrude into a common source/detection cavity 35 covered by an access panel 33. 30 In at least the preferred embodiment of an on-line analyser 10, the bulk of the modules 12, 14 act as a radiation shield. The lower L-shaped module 14 has protruding lugs such as 38 which meet with corresponding recesses such as 40 in the downward facing surface of WO 2008/151378 PCT/AU2008/000850 5. the upper L-shaped module 14. The lugs 38 and recesses 40 allow alignment of the upper 12 and lower 14 modules. Figure 5 shows the lugs 38 in closer detail. The on-line analyser 10 may also have a pair of U-shaped shielding modules 46, 48 located alongside the L-shaped modules 12, 14 and defining a shielding tunnel 50 for passing of the 5 conveyor 18. There may be one or more concrete foundations such as 55 supporting the shielding modules 46, 48 and lower L-shaped module 14. The concrete foundations 55 may provide further shielding. In environments where the conveyor and/or analyser 10 are elevated it may be desirable not to include the concrete foundations 55 and the analyser 10 may instead be supported by a steel framework. 10 Figure 2 depicts another embodiment of an on-line analyser 10 where parts similar to parts of the embodiment of figure 1 are similarly numbered. As displayed by the embodiment of figure 2 the source/detection cavity 35 typically includes optional shielding elements which in this embodiment are fabricated from tungsten 37. The tungsten elements 37 reduce the number of gamma-rays emitted by the radioisotope entering the 15 detectors, although in some circumstances such as when using 24 Am-Be it is desirable not to reduce the gamma rays to undetectable levels. The lower module 14 also includes a blanking tube 39 positioned in the vacant cavity 24. The upper module 12 includes two (2) further detection holders 41 and 43 located in respective passageways 30 and 32. The on-line analyser of figure 2 also comprises an idler roller support frame 42 mounted to 20 the lower module 14. In this embodiment the frame 42 is screwed to the lower module 14 via an intermediate mounting bracket 45. The frame 42 includes idler rollers such as 44 for supporting the conveyor belt 18. These idler rollers 44 reduce sagging of the conveyor belt 18 which is otherwise unsupported through the tunnel 16. In an altemate arrangement the idler support rollers 44 may be replaced with wear or support plates (not shown). 25 The embodiment of the on-line analyser 10 shown in figure 2 includes optional shielding slabs or inserts such as 57 to be placed under a conveyor belt beneath each U-shaped shielding module 46, 48. Figures 6 and 7 show one embodiment of the radiation source holder comprising a radioisotope and a rod 34 which is elongate and foldable. The rod 34 has a front end 30 component 56 that holds a neutron or radioactive source and a back end component 58. The front 56 and back 58 end components are threaded together to allow an incorporated swivel motion. The rod 34 may be retracted within the lower module 14, thus blocking the WO 2008/151378 PCT/AU2008/000850 6. radiation. The front 56 and back end 58 components can be longitudinally separated to allow folding relative to one another at about 900 as depicted in figure 7. The front end 56 of the rod 34 is locked into a 90* angle relative to the back end 58. This prevents the radiation source holder 34 from protruding too far from the lower module 14 when it is 5 withdrawn such that the radioisotope moves from a position adjacent to the conveyor belt to a storage position that allows maintenance to be carried out. In some embodiments, there may be mechanised means for retraction of the radiation source holder 34. No radiation source holder would be necessary if an electronic radiation source is used. Now that several preferred embodiments of an on-line analyser have been described, it 10 will be appreciated that at least some embodiments have the following advantages: * The analyser can be installed without modification to the plant, possibly between existing conveyor belt idlers; * It is relatively simple to co-join the two L-shaped modules; * A range of dimensions of the L-shaped module allows different tunnel 15 dimensions and therefore allows the design to be flexible for different conveyor belts; 0 There is no personnel exclusion or safety zone around the analyser, so that a person proximal to the analyser would experience acceptable radiation levels; and 20 0 The analyser can be used without alteration for a wide range of plant applications. It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present 25 embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

1. An on-line analyser comprising a pair of L-shaped modules being arranged to connect to one another to together define a tunnel through which a conveyor belt passes, the L-shaped modules configured to be oriented transverse to the 5 conveyor belt and located between conveyor belt idlers..

2. An on-line analyser as defined in claim 1 wherein the analyser is arranged for elemental analysis of materials conducted through the tunnel by the conveyor belt.

3. An on-line analyser as defined in any one of the preceding claims wherein one of the 10 L-shaped modules is an upper module resting on the other of the L-shaped modules being a lower module.

4. An on-line analyser as defined in claim 3 wherein one leg of each of the L-shaped modules is oriented substantially upright and dimensioned to preset the height of the tunnel. 15

5. An on-line analyser as defined in claim 4 wherein the other leg of each of the L shaped modules is dimensioned to preset the width of the tunnel.

6. An on-line analyser as defined in any one of claims 3 to 5 wherein one of the L shaped modules defines a cavity for containing either a radiation source or a radiation detector. 20

7. An on-line analyser as defined in claim 6 wherein the cavity is located in either of the upper or the lower L-shaped modules.

8. An on-line analyser as defined in either of claims 6 or 7 wherein the cavity includes a passageway.

9. An on-line analyser as defined in any one of claims 6 to 8 wherein the 25 cavity contains both a radiation source and a radiation detector.

10. An on-line analyser as defined in any one of claims 6 to 9 wherein both of the L-shaped modules define a cavity for containing either a radiation source or a radiation detector. 8

11. An on-line analyser as defined in any one of the preceding claims also comprising a shielding module located alongside the L-shaped modules.

12. An on-line analyser as defined in claim 11 wherein the shielding module is U shaped. 5

13. An on-line analyser as defined in claim 12 wherein the U-shaped shielding module is one of two shielding modules located either side of the L-shaped modules.

14. An on-line analyser as defined in any one of the preceding claims wherein one of the pair of L-shaped modules has alignment means configured to mate with corresponding alignment means of the other of the pair of L-shaped modules. 10

15. An on-line analyser as defined in claim 8 also comprising a radiation source holder being elongate and foldable along its length.

16. An on-line analyser as defined in claim 15 wherein the source holder is retractably received in the passageway.

17. An on-line analyser as defined in any one of the preceding claims further 15 comprising a radiation source.

18. An on-line analyser as defined in any one of claims 1 to 16 further comprising a neutron source including a radioisotope or a neutron generator including a Deuterium-Tritium neutron generator.

19. An on-line analyser as defined in claim 15 wherein a radioisotope is contained by the 20 radiation source holder.

20. An on-line analyser as defined in any one of the preceding claims wherein the analyser is arranged to detect scattered or induced radiation from the material.

21. An on-line analyser as defined in claim 20 wherein the analyser is arranged to detect neutron-induced gamma-rays. 25

22. An on-line analyser as defined in claim 21 wherein the analyser is arranged to detect gamma rays induced by one or more of neutron ineleastic scattering, thermal neutron capture, delayed activation or nuclear particle ractions. 9

23. An on-line analyser as defined in any one of the preceding claims also comprising a support frame mounted to one of the L-shaped modules and including guide means for supporting the conveyor beft.