Dispersion apparatus

Abstract

There is provided a dispersion apparatus for use with a solid fuel burner. The dispersion apparatus comprises a passage through which particulate material may flow toward an outlet region for dispersal therefrom, the flow being at least in part rotational about the longitudinal axis of the passage. The dispersion apparatus also comprises a downstream guide means arranged within the passage at or near the outlet region, the downstream guide means configured to at least reduce the rotational motion so that the flow progresses toward the outlet region in a substantially uniform manner in a direction aligned with a longitudinal axis of the passage.

Claims

1. A dispersion apparatus for use in conditioning the flow of a particulate material flowing therethrough, the apparatus comprising: a passage through which particulate material may flow from an inlet region toward an outlet region for dispersal therefrom, the flow being at least in part, rotational about a longitudinal axis of the passage; a downstream guide arranged within the passage, the downstream guide configured to at least reduce the rotational motion so that the flow progresses from the downstream guide toward the outlet region in a substantially uniform manner in a direction aligned with the longitudinal axis of the passage; an upstream guide provided upstream of the downstream guide and configured for introducing into the flow a component of angular or rotational motion for moving the particulate material about the longitudinal axis of the passage; wherein the upstream guide comprises more than one spiral, the spirals arranged within the passage and configured so as to extend along the passage from the inlet region to the downstream guide; and wherein the inlet region comprises a manifold arrangement which serves to direct the particulate material into an upstream region of the passage, wherein the manifold arrangement is configured to divide incoming particulate material into a number of streams of flow, such that each stream of flow is directed toward a respective spiral.

2. A dispersion apparatus according to claim 1, wherein the inlet region comprises an inlet configured so as to introduce the particulate material into the passage in a direction tangential thereto.

3. A dispersion apparatus according to claim 1, wherein the spiral comprises a sidewall portion provided at a peripheral edge region of the spiral and arranged for preventing the particulate material travelling beyond the periphery of the passage at the peripheral edge region, the sidewall portion arranged so as to extend along at least a portion of the peripheral edge region.

4. A dispersion apparatus according to claim 1, wherein the downstream guide comprises one or more protrusions arranged about the longitudinal axis of the passage, the or each protrusion configured so as to engage with the passing flow of particulate material.

5. A dispersion apparatus according to claim 1, wherein the downstream guide comprises one or more annular rings arranged concentric with the passage and configured so as to engage with the passing flow of particulate material.

6. A dispersion apparatus according to claim 1, wherein the downstream guide comprises a plurality of elongate elements spaced about a periphery of the passage and configured so as to engage with the passing flow of particulate material, each elongate element having an elongate direction which is aligned with the longitudinal axis of the passage.

7. A dispersion apparatus according to claim 1, further comprising a shroud member which is configured to define at least a portion of the passage.

8. A dispersion apparatus according to claim 7, wherein the shroud member surrounds a portion of the downstream guide or upstream guide.

9. A dispersion apparatus according to claim 7, wherein the passage is defined, at least in part, by an interior surface of an annular channel in which the dispersion apparatus is installed.

10. A dispersion apparatus according to claim 1, wherein the flow of a particulate material is a mixture of gas and solid particles.

11. A method for modifying the path of travel of particulate material flowing through a passage of a dispersion apparatus or dispersion lance from which the particulate material is to be dispersed from, the method comprising: introducing into the flow of particulate material at an inlet region of the passage upstream and proximal of an outlet region, a component of angular or rotational motion for moving the particulate material about the longitudinal axis of the passage by providing more than one spiral within the passage, the spiral configured to extend along the passage from the inlet region to a downstream guide; directing the particulate material into an upstream region of the passage with a manifold arrangement, wherein the manifold arrangement divides the particulate material into a number of streams of flow, such that each stream of flow is directed toward a respective spiral; and modifying the path of flow of the particulate material using the downstream guide of the dispersion apparatus or dispersion lance to at least reduce any rotational motion of the flow about a longitudinal axis of the passage so that the flow progresses from the downstream guide toward the outlet region in a substantially uniform manner in a direction aligned with the longitudinal axis of the passage.

12. A method according to claim 11, wherein introducing the component of angular or rotational motion into the flow comprises introducing the particulate material into the passage in a direction tangential thereto.

13. A method according to claim 11, wherein modifying the path of flow of the particulate material at the outlet region comprises providing one or more protrusions arranged about the longitudinal axis of the passage, the or each protrusion configured so as to engage with the passing flow of particulate material.

14. A method according to claim 11, wherein modifying the path of flow of the particulate material at the outlet region comprises providing a plurality of elongate elements spaced about a periphery of the passage and configured so as to engage with the passing flow of particulate material, each elongate element having an elongate direction which is aligned with the longitudinal axis of the passage.

15. A method according to claim 11, wherein the flow of particulate material is a mixture of gas and solid particles.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order to facilitate a better understanding of the underlying inventive concept, various embodiments of the invention will now be further explained and illustrated, by way of example only, with reference to any one or more of the accompanying drawings, in which:

(2) FIG. 1A shows an isometric view of one embodiment of a dispersion apparatus arranged in accordance with the present invention;

(3) FIG. 1B shows an isometric view of the lower portion of the embodiment of the dispersion apparatus shown in FIG. 1A;

(4) FIG. 1C shows an isometric view of the upper portion of the embodiment of the dispersion apparatus shown in FIG. 1A:

(5) FIG. 2A shows an isometric view of another embodiment of a dispersion apparatus arranged in accordance with the present invention;

(6) FIG. 2B shows an isometric view of embodiment of the dispersion apparatus shown in FIG. 2A, but showing detail otherwise hidden in FIG. 2A;

(7) FIG. 2C shows a schematic cross section of the embodiment shown in FIGS. 2A and 2B taken along the passage at the location generally indicated by the arrow (showing the sidewall portions provided at the peripheral edge of the spiral features);

(8) FIG. 3A shows an elevation view of the embodiment of the dispersion apparatus shown in FIGS. 1A to 1C when arranged with a single feed chute (showing particle flow);

(9) FIG. 3B shows an elevation view of the embodiment of the dispersion apparatus shown in FIGS. 1A to 1C when arranged with a dual feed chute arrangement (showing particle flow);

(10) FIG. 3C shows an alternative elevation view of the embodiment of the dispersion apparatus shown in FIG. 3A (showing particle flow);

(11) FIG. 4A shows an isometric view of the inlet region for the embodiment of the dispersion apparatus shown in FIGS. 1A to 1C (showing particle flow);

(12) FIG. 4B shows an alternative isometric view (rotated slightly) of the embodiment of the dispersion apparatus shown in FIG. 4A (showing particle flow);

(13) FIG. 4C shows an isometric elevation view of the lower portion of the embodiment of the dispersion apparatus shown in FIG. 4A and FIG. 4B (showing particle flow):

(14) FIG. 5A shows an isometric view of the estimated particle flow pattern around the mid-section of the embodiment of the dispersion apparatus shown in FIGS. 1A to 1C;

(15) FIG. 5B shows an isometric view of the estimated particle flow pattern at the lower section for the embodiment of the dispersion apparatus shown in FIGS. 1A to 1C;

(16) FIG. 6 shows an isometric view of the embodiment of the dispersion apparatus shown in FIGS. 1A to 1C;

(17) FIG. 7 shows a close up isometric view of the mid-section of the embodiment of the dispersion apparatus shown in FIG. 6;

(18) FIG. 8 shows an embodiment of the dispersion apparatus installed within a conventional single entry solid fuel burner;

(19) FIG. 9 shows a cut away view of an embodiment of the dispersion apparatus as mounted in, for example, a flash smelting burner incorporating a dual feed entry arrangement;

(20) FIG. 10 shows an isometric view of another embodiment of a dispersion apparatus arranged in accordance with the present invention;

(21) FIG. 11 shows an isometric view of a further embodiment of a dispersion apparatus arranged in accordance with the present invention;

(22) FIG. 12 shows, for one trial embodiment of a dispersion apparatus arranged in accordance with the principles described herein, a graphical representation of percentage of ideal mass mass flow versus angular location around the dispersion cone, as compared to a conventional dispersion configuration; and

(23) FIG. 13 shows, for one trial embodiment of a dispersion apparatus arranged in accordance with the principles described herein, the actual improvement in combustion efficiency observed at an industrial flash smelting facility, as compared to a conventional dispersion configuration.

(24) In the figures, like elements are referred to by like numerals throughout the views provided. The skilled reader will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to facilitate an understanding of the various embodiments of the invention described herein. Also, common but well understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to provide a less obstructed view of these various embodiments of the present invention. It will also be understood that the terms and expressions used herein adopt the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.

(25) Specifically, reference to positional descriptions, such as lower and upper, and associated forms such as uppermost and lowermost, are to be taken in context of the embodiments shown in the figures, and are not to be taken as limiting the invention to the literal interpretation of the term, but rather as would be understood by the skilled reader. Furthermore, reference to upstream and downstream, and associated forms, are to be taken in context of the embodiments shown in the figures, and are not to be taken as limiting the invention to the literal interpretation of the term, but rather as would be understood by the skilled reader.

DETAILED DESCRIPTION

(26) FIGS. 1 to 11 show a dispersion apparatus for a solid fuel burner designed to deliver a particle stream to a combustion environment in a manner that provides favourable conditions for combustion of the solid particles. A solid fuel burner could include any burner known in the art, for example, a concentrate burner.

(27) FIG. 1A through 1C shows one embodiment of a dispersion apparatus (hereinafter, disperser 2)often referred to as a dispersion or injection lance (refer FIG. 6 and FIG. 7 for corresponding isometric line drawings of the embodiment shown in FIGS. 1A through 1C). The disperser 2 comprises a passage 8 having a longitudinal axis A and through which the particulate material (hereinafter, particles) may travel or flow in a direction 12 toward an outlet region 16 from which the particles are dispersed.

(28) The general path of travel 12 of the particles through the passage 8 is in a direction substantially aligned with the longitudinal axis A. In all embodiments shown in the Figures and described herein, the passage 8 is generally cylindrical of a linear nature and its longitudinal axis A is aligned vertically. Thus, movement of the particles through the passage 8 is due to the influence of gravity. It will be appreciated, however, that a vertical alignment is not exclusively required as arrangements could be realised in which movement of the particles is achieved by other means, such as for example, gas flow.

(29) With reference to FIGS. 1A-1C, the disperser 2 includes a downstream guide assembly (hereinafter, conditioning section 36) provided near the outlet region 16 which is configured for conditioning the flow of the particles so as to at least reduce any angular or rotational motion present in the flow (which is directed about the longitudinal axis A) so that the flow progresses in a more substantially uniform manner in a direction aligned with the longitudinal axis A of the passage 8 toward the outlet region 16. The downstream guide assembly is provided in the form of an assembly of a plurality (32 in total) of elongate ribs 40 (of square cross section, and approximately 10 mm10 mm in the embodiment shown) spaced about and near the periphery of the passage 8 (or the interior wall of a cylindrical shroud provided in the form of a cylindrical tube section 28).

(30) As shown in FIGS. 1A-1C, the elongate ribs 40 are arranged substantially parallel one another such that an elongate direction of each elongate ribs 40 is aligned with the longitudinal axis A of the passage 8. In this manner, the assembly of the elongate ribs 40 forms a cage like structure. The length of the elongate ribs 40 may be dimensioned as appropriate to the circumstance at hand.

(31) As noted, the assembly of elongate ribs 40 serves to condition the flow of the particles prior to dispersion from the outlet region 16. In this manner, the elongate ribs 40 are configured or shaped so as to engage the passing flow of particles so as to at least reduce any non-uniformity in the flow so that it progresses toward the outlet region 16 in a manner more aligned with longitudinal axis A. This arrangement has been found to have the effect of improving the spatial distribution of the particles at or near the outlet region 16 for dispersal purposes. In some embodiments, the configuration of the conditioning section 36 serves to provoke or facilitate an increase in radial movement or scatter of the particles as they move toward the outlet region region 16 which, at least in part, reduces any component of angular or rotational motion in the flow.

(32) The disperser 2 further comprises an upstream guide assembly (hereinafter, guide 20) arranged within the passage 8 and configured so as to modify the general path of travel of the particles through the passage 8 so as to cause movement of the particles about the longitudinal axis A as they move toward the outlet region 16.

(33) The modification to the particle flow by way of the guide 20 serves to introduce a component of angular or rotational motion (ie. movement in a circumferential direction relative to the longitudinal axis A) into the flow so as to cause the particles to move radially outward from the axis A and toward the periphery of the passage 8. When subsequent conditioning of the flow is conducted by way of the conditioning section 36, a more spatially uniform distribution of the particles at or near the outlet region 16 is achieved which has been shown to improve combustion efficiency rates when used to feed a concentrate burner. When particles conditioned in this manner are released from disperser 2 into a subsequent combustion process, the efficiency levels of such combustion processes have been found to improve (as shown in FIG. 13). Thus, the disperser 2, and certain variations, may find favourable application in the fields of flash smelting of copper, lead or nickel concentrates, flash converting of sulphide mattes or other like fields where spatial uniformity of feed flow is considered advantageous.

(34) The particles are introduced into the passage 8 by way of a feed means (such as for example a feed chute) provided at an inlet region 15 upstream of the guide 20. Thus, the inlet region 15 is fluidly connected to a feed chute 24 (see FIG. 3A). The passage 8 therefore serves as a conduit providing passage for the particles to travel toward the outlet region 16 for dispersal purposes.

(35) The skilled person will appreciate that some feed arrangements will not introduce the particles in a symmetrical (in orientation and velocity) manner, thereby causing the particles to follow different trajectories within the passage 8 (albeit in the general downstream direction) and making it difficult to reliably condition the particles into a substantially uniform stream. Thus, the motion imparted by the guide 20 has been found to encourage the particles into a more predictable arrangement so that they can be more reliably conditioned by conditioning section 36 and dispersed from outlet region 16 more uniformly.

(36) The disperser 2 further includes a shroud provided in the form of a section of cylindrical tube 28 which defines an outer wall of a portion of the passage 8. The section of cylindrical tube 28 extends along the passage 8 to the extent that it substantially surrounds the guide 20 and/or elongate ribs 40 of conditioning section 36 (as discussed further below). A ring 29 is provided about the uppermost end of the cylindrical tube 28 and arranged so as to prevent particles from entering the region between the cylindrical tube 28 and an outer sleeve of the disperser (not shown).

(37) As noted, the guide 20 is configured so as to introduce a component of angular or rotational motion to the particles as they move from the feed chute 24 (see FIG. 3A) toward the outlet region 16. This component of angular or rotational motion serves to move the particles about their general direction of travel as they move toward the outlet region 16. The rotational motion assists in the development of centripetal forces which encourages the particles into a more predictable arrangement for subsequent conditioning.

(38) For the embodiments shown throughout the Figures, the guide 20 comprises four spirals 32 which extend along a portion of the length of the guide 20. Each spiral 32 comprises a surface defined by a three dimensional curve wound uniformly about a portion of the longitudinal axis (which is aligned concentric with the longitudinal axis A) of the guide 20, at a distance outward therefrom (width dimension). The width dimension defines the outermost or peripheral edge of each spiral 32, and is generally uniform along each spiral's length.

(39) The slope of each spiral 32 is a function of the pitch and the diameter (more specifically, the circumference)which is the length of the spiral when measured parallel to its axis (for the embodiments shown and described herein, generally aligned with longitudinal axis A). The pitch of each spiral 32 is commensurate with the degree of angular velocity imparted to the particles.

(40) For the majority of the embodiments shown in the Figures, the pitch of each spiral 32 is uniform along its length. However, the pitch can be non-uniform so to allow the rotational velocity component imparted to the particles to be varied along certain regions of the guide 20 (see the embodiment shown in FIG. 11 in which the pitch is varied along the length of the spiral section 156).

(41) There is no finite number of times that each spiral 32 needs to wind about its axisonly sufficient length is required so that the particles are encouraged to move towards the periphery of the passage 8 so they reach the interior surface of the cylindrical tube 28. The length of each spiral 32 depends on how easily the particulate material flows. The skilled person will appreciate that a balance exists between the flow velocity of the material and the nature of the particulate material, ie. if the velocity of the particles is too slow, then the particles are (a), less likely to reach the periphery of the passage 8, and (b) blockages may occur. Thus, the flow velocity of the particles is controlled by the number of spirals employed, and their respective pitch. For the case of a more readily flowable particulate material, a guide arrangement having a flatter pitch with fewer spirals may be preferable. For a particulate material more resistant to flow, a guide arrangement having a steeper pitch (so to increase particle velocity) with a larger number of spirals may be more desirable.

(42) With reference to FIGS. 2A, 2B and 2C, the spiral 32 features may be provided with a sidewall portion 22 arranged at or near the outermost or peripheral edge of the spiral 32. In this manner, the sidewall portion 22 is configured as an edge barrier portion for preventing particulate material from travelling beyond the periphery of the passage 8. As shown in at least FIG. 2C, the sidewall portion 22 is arranged so as to extend away from the edge region (and substantially upstream thereof) of the surface of the spiral 32 so as to restrain radial movement of the particles flowing therealong.

(43) As shown in FIGS. 2A and 2B, the sidewall portion 22 is configured to extend along at least a portion of the peripheral edge of each spiral 32 at sections not covered by a section of the cylindrical tube 28. Thus, it will be understood that the sidewall portion 22, where ever provided, seeks to prevent the particles from moving beyond the extremities of the passage 8 and further assists in establishing the generally angular or rotational particle flow through and about the passage 8. It will be further appreciated that the sidewall portion 22 can be configured in any manner which serves the latter purpose. It will be appreciated that for embodiments of the disperser 2 in which the tube 28 completely covers the spirals 32, the need for the sidewall portion 22 might not exist.

(44) The disperser 2 further comprises a column 18 extending from the inlet region 15 toward the outlet region 16 and about which the guide 20 is arranged. The column 18 is configured so as to provide support for the guide 20. The column 18 is provided in the form of a tubular elongate member of substantially uniform cross section along the majority of its length, terminating at a downstream end in the form of a cone portion 17, often referred to as a dispersion cone (shown in FIG. 8 and FIG. 9). The column 18 is configured for allowing a gas to flow through the hollow of the tubular region for release at the cone portion 17. The column 18 is arranged so that gas exiting from the cone portion 17 is directed so as to assist dispersion of the particles exiting from the outlet region 16 of the disperser 2. The column 18 and the guide 20 are fixed relative to one another.

(45) With reference to FIGS. 3A to 3C, estimated flow streams are shown for two different particle feeding arrangements illustrating the predicted flow pattern of the particles caused by the spirals 32; FIG. 3A and FIG. 3C both show a single feed arrangement, and FIG. 3B shows a dual feed arrangement.

(46) The conditioning section 36 may also include an annular ring 42 provided downstream of the elongate ribs 40 and provided at or near the periphery of the passage 8 (generally at or near the interior wall of the cylindrical tube 28).

(47) The inlet region 15 comprises a manifold arrangement which serves to direct particles received from the feed chute 24 into an upstream region of the passage 8. The manifold arrangement is configured so as to divide incoming particulate matter into a number of streams of flow (generally four separate streams as shown), the configuration being such that each stream of flow is directed toward a respective spiral 32.

(48) FIG. 4A and FIG. 4B each show diagrammatic representations of the estimated flow patterns of different embodiments of an entry region (15/15) which are each configured to transition the incoming particles from the feed chute to respective spirals 32. In FIG. 4A, the entry region 15 is configured with each spiral 32 having an extended portion 35 which extends sufficiently relative to the passage 8 so that the incoming feed impacts the portion 35 causing a substantial abrupt change in the state of flow (operating such as a deflector of the particles in some configurations). FIG. 4B shows an entry region 15 which is arranged such that a smooth transition from the feed chute to the spiral 32 is provided for. In the arrangement shown in FIG. 4B, the inlet is angled relative to the passage 8 so that the particles are introduced into the passage in a substantially tangential manner.

(49) FIG. 4C shows the effect that the assembly of elongate ribs 40 are predicted to have on the particles exiting the spiral 32. It can be seen that the particles are substantially spatially uniformly distributed around the circumference of the interior wall of the cylindrical tube 28 as they continue to progress downward toward the outlet region 16.

(50) Similarly, FIG. 5A and FIG. 5B show close up diagrammatic representations of the flow patterns observed by discrete element modelling showing the particle flow through the spirals 32 (FIG. 5A) and the conditioning section 36 (FIG. 5B).

(51) A number of specific arrangements of disperser configurations are outlined below in the context of operational use in a conventional flash, concentrate or solid fuel burner.

(52) FIG. 8 shows the embodiment of the disperser 2 shown in FIG. 1A to FIG. 1C, as mounted inside a conventional single-entry burner 44. The disperser 2 is fed by a single feed chute 24 which enters through the upper portion of a water cooled sleeve 48. Particulate material enters the disperser 2 through the feed chute 24 which is divided internally into four sections. Each section of the feed chute 24 feeds a baffled inlet 52. The baffled inlet 52 directs the four particle streams toward respective spirals 32 (generally hereinafter, spiral section 33) each of which then guides the particles toward and against the interior wall of the cylindrical tube 28.

(53) The particles exit the spiral section 33 with vertical and angular (circumferential) velocity components. As the particles interact with the elongate ribs 40, located in the conditioning section 36, their circumferential velocity component reduces. The particles then descend along the length of the conditioning section 36, and interact with annular ring 42 provided at the lowermost or downstream end of the elongate ribs 40, and aligned substantially transverse and concentric with the longitudinal axis A as shown. This interaction serves to provoke inter-particle collisions and/or scatter which leads to the particles becoming more evenly dispersed (as shown in FIG. 4C). The resulting mass flow rate distribution (marked, Present Invention), presented in graphical form in FIG. 12, is shown to be advantageously more spatially uniform than that produced by a conventional disperser arrangement (marked, Prior Art).

(54) FIG. 9 shows an embodiment in which the disperser 2 is mounted inside a conventional double-entry burner 60. In this arrangement, the disperser 2 is fed by two feed chutes 62 which enter through an upper portion of a water-cooled sleeve 64. Concentrate particles enter the disperser 2 through the two feed chutes 62, each of which are divided into two sections thereby providing four streams of flowing particles. Each section of feed chute 62 feeds a baffled inlet 68 provided in the disperser 2. The baffled inlet 68 serves to direct the four particle streams to an entry region 72 upstream of the spirals 32. The spirals 32 then guide the particles toward and against the interior wall of the cylindrical tube 28.

(55) The particles exit the spiral section 33 with vertical (downward direction) and circumferential velocity components, and encounter the conditioning section 36. As the particles interact with elongate ribs 40 in the conditioning section 36, their circumferential velocity component is reduced. The particles continue to descend along the length of the conditioning section 36 to then interact with the annular ring 42 in a manner previously described.

(56) FIG. 10 shows an embodiment of a disperser 90 intended for mounting inside a conventional single-entry burner. In this arrangement, the cylindrical tube 28 tapers along its longitudinal axis in the direction of the particle flow. Furthermore, this embodiment of the disperser 90 omits elongate ribs 40, but comprises an internal nozzle ring (hereinafter, annular ring 128) positioned at or near the downstream end of a conditioning section 132 (analogous to the conditioning section 36). Particles enter the disperser 90 through a feed chute (24 as shown in FIG. 8) which is divided internally into four sections for feeding a baffled inlet region 92, so guiding each of the particle streams toward respective spirals 32 in spiral section 33.

(57) The particles exit the spiral section 33 with vertical and circumferential velocity components. The particles then interact with the annular ring 128 located at the lower most edge of cylindrical tube 28 and are forced to alternately converge and diverge from the centre of the disperser 90. This arrangement serves also to promote inter-particle collisions thereby promoting greater spatial uniformity and conditioning the flow so as to progress in a more uniform manner in a direction aligned with the longitudinal axis A of the passage toward the outlet region 16.

(58) FIG. 11 shows an embodiment of a disperser 140 for mounting within a water cooled sleeve (not shown), fed by a conventional single-entry feed arrangement. The particles enter the disperser 140 through a single feed chute (not shown) which is divided internally into four sections for feeding a baffled inlet region 148. The baffled inlet region 148 directs the four concentrate streams toward (respective) spirals 152 (in spiral section 156) which serve to guide the particles toward and against the interior wall of the water cooled sleeve 150 in which the disperser 140 is mounted. In this arrangement, the spirals 152 have a decreasing pitch along their respective lengths. This variable pitch arrangement serves to increase the angular velocity component of the particle stream as it passes through the length spiral section 156. When the particles exit the spiral section 156, they continue to move along or adjacent the interior wall of the water-cooled sleeve 150 and lose their angular velocity due to, at least in part, friction caused by contact with the interior wall of the water-cooled sleeve. In this arrangement, the spirals 156 each terminate with wedge like portions 160 which serve to engage with the passing flow so as to provoke interparticle scatter/movement for reducing the angular or rotational motion present in the flow.

(59) FIG. 13 shows the actual improvement in combustion efficiency observed at an industrial flash smelting facility, when utilising embodiments of the claimed invention compared to conventional arrangements typical of prior art configurations. For a four day period, operating with consistent feed characteristics, feed rate, and product quality, the remnant oxygen in the smelter off-gas was found to be reduced significantly when a disperser arranged in accordance with the principles of the present invention was in use. As will be clear from FIG. 13, the level of oxygen present in the smelter off-gas is seen to drop from an average in excess of 5% to less than 1% due to the improved combustion effecting a near complete consumption of the available oxygen.

(60) The skilled reader will appreciate that various configurations seeking to condition the flow at or near the outlet region of the disperser 2 are possible. For example, in another embodiment (not shown), the cylindrical tube 28 may be arranged so as to taper along its longitudinal axis in the direction of the particle flow, and the conditioning section 36 provided at any region within the tapering section of the cylindrical tube 28. As one example arrangement of this type, the conditioning section 36 could be arranged having two annular rings: a trailing annular ring provided at or near the downstream most end of the cylindrical tube 28, and a leading annular ring provided at or near the entrance to the conditioning section 36 and, of course, upstream of the trailing annular ring.

(61) In an arrangement of this nature, particles enter the disperser through a feed chute (which might be again, for example, subdivided internally into four sections for feeding a baffled inlet provided in the disperser). The baffled inlet guides the four particle streams toward respective spirals 32 which then guides the particles toward and against the interior wall of cylindrical tube 28. It will be understood that the particles exit the spiral section 33 with vertical and circumferential velocity components.

(62) As the particles engage or interact with the leading annular ring located at or near the entrance to the conditioning section 132, they are forced to alternately converge and diverge from the centre of the disperser. The trailing annular ring may be provided having one or more lip or protruding formations which serve to encourage further particle scatter upon impact. Arrangements of this nature can be therefore assist in promoting inter-particle collisions and/or scatter, so promoting increased radial movement and which has been found to lead to a more uniform circumferential particle distribution for improving spatial uniformity.

(63) The skilled reader will readily appreciate the materials and manufacturing techniques which might be relevant for constructing the componentry described herein. For example, 316 stainless steel finds broad application to many embodiments of the apparatus, as does various lower grade carbon steels and other stainless steel specifications.

(64) The words used in the specification are words of description rather than limitation, and it is to be understood that various changes may be made without departing from the spirit and scope of the invention. Those skilled in the art will readily appreciate that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations are to be viewed as falling within the ambit of the inventive concept.

(65) Moreover, the word comprising and forms of the word comprising as used in this description, and the claims which follow, are not intended to be limited to the invention claimed so as to exclude any such modifications, alterations, and combinations. Furthermore, the word include or variations such as includes or including, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.