GB2513424A

GB2513424A - Apparatus for reducing particle size

Info

Publication number: GB2513424A
Application number: GB1310766.9A
Authority: GB
Inventors: Abdul-Karem Souleyman Mouhamed
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-06-17
Filing date: 2013-06-17
Publication date: 2014-10-29
Anticipated expiration: 2033-06-17
Also published as: GB2513424B; GB201310766D0

Abstract

A particle size reduction apparatus, or grinder, has a spherically shaped chamber (fig.1) and spherically shaped internal particle reduction tool (fig.5). In a method of usage of the apparatus, grinding beads are introduced into the chamber. The apparatus and method may be used from the production of micro or nano scales particles.

Description

APPARATUS FOR REDUCING PARTICLE SIZE

Field of the Invention

[0001] The present invention relates to an apparatus for reducing the size of material particles. More particularly, the present invention relates to a modular apparatus for reducing the size of material particles in the sub-millimeter domain.

Background of the Invention

[0002] Many methods and devices have been devised for reducing the size of material particles in the micrometric and nanometric domains. An important advantage of nanotechnology is the vastly increased ratio of surface area to volume present in many nanoscale materials, which enables new quantum mechanical effects. Examples include altering the electronic properties of solids when their particle size is greatly reduced, or their optical properties which may become a function of the particle diameter. Such effects do not occur in a reduction from the macro to the micro domain, but become pronounced when the nanometer domain is reached. Physical properties of materials can also be altered by the inclusion of nanoparticles therein. When suffused within a bulk material, nanoparticles can influence the mechanical properties of that material, such as its stiffness or elasticity. For example, polymers can be reinforced by nanoparticles, resulting in novel materials which can be used as lightweight replacements for metals.

[0003] Polymeric nano-materials have attracted much interest because their properties provide a wide range of new applications, such as cargo storage and delivery, EMO (Electronics Magnetics Optoelectronics) devices, coatings, and the like. Various processes are known for preparing such materials, and involve predominantly wet synthesizing synthetic methods such as the dispersion of preformed polymers, or the polymerization of monomers in dispersed media.

[0004] In that context, nano-powders are solid powders of nanoparticles, often containing micron-sized nanoparticle agglomerates, and nanoparticle dispersions are suspensions of nanoparticles in water or organic solvents.

Moreover, at such at small scales, encapsulation of materials into capsules becomes discrete. Nano-encapsulation is the coating of one or more substances within another material at nanometre scales. The encapsulated material is commonly referred to as the internal phase or core material, and the encapsulation material is known as the external phase or shell. As the core material for different nano-capsules may vary greatly in size, shape and composition, the encapsulated particle can be have an appearance that ranges from having regular, uniform shape through to being jagged and irregular. A main advantage of the nano-encapsulation technique is to temporarily protect a core material and then release it when required. Examples of applications for this technique include targeted drug delivery systems that release the drug only when the drug has arrived at the site in the body where it is required timed release drug delivery where the nano-encapsulation material slowly allows the drug to be released into the body embedded fragrances for branded perfumed clothing food additions and enhancements such as Omega-3 fatty acid additions to bread that do not alter taste; and increasing shelf life and stability of products like vitamins.

[0005] A constant challenge in all such processes is that the behavior of fluids can differ between the macroscopic and microscopic scales, in that factors such as surface tension, energy dissipation and fluidic resistance may come to dominate the process. At small scales, for instance with channel diameters of approximately 100 nanometers, some interesting and sometimes unintuitive properties can appear. In particular, the Reynolds number (which compares the effect of momentum of a fluid to the effect of viscosity) can become very low. An important consequence of this effect is that fluids do not necessarily mix in a conventional manner, but molecular transport between them must be achieved through diffusion.

[0006] Preferred processes for preparing polymeric nanomaterials, nanopowders and nanoparticle dispersions should be fast, preferably consisting of a one-step procedure, with little energy requirements and limited impact on the environment. They should also preferably offer control of the output polymer microstructure and composition, and of the characteristics of the polymeric nanomaterial, for example to obtain particles that are hollow, or configured with a multifunctional surface. The combination of all these requirements represents a challenge, for which few and sub-optimal solutions have so far been proposed.

Summary of the Invention

[0007] According to a first aspect of the present invention, there is provided a system for reducing the particulate size of a material, comprising a chamber having at least first and second portions, wherein each of the first and second portions is releasably connected to the other and the portions collectively define a substantially spherical volume, and wherein the first portion comprises at least one inlet and the second portion comprises at least one outlet a substantially spherical tool located within the chamber and driven by a shaft through a substantially central aperture of the first portion; and means for driving the shaft.

[0008] This relatively simple combination provides a material processing system suitable for use in very many environments, which is not constrained by imperatives of room and/or building safety aspects such as are dictated by the very high pressures, heat dissipation requirements and such other hazards associated with conventional systems.

[0009] In an embodiment of the above system, the tool may comprise peripheral striations projecting from the substantially smooth surface of the tool, the striations being substantially parallel to one another and substantially perpendicular to the shaft in use.

[0010] This configuration advantageously facilitates the grinding or such other mechanical treatment of any one or more materials located within the chamber, and mitigates effects associated with high-speed volume displacement of the chamber contents.

[0011] In a variant of this embodiment, at least some of the peripheral striations may have a substantially square section. In an alternative variant of this embodiment, at least some of the peripheral striations may have a substantially convex section. In another variant of this embodiment, at least some of the peripheral striations may have a substantially concave section.

[0012] In an embodiment of the above system, at least some the striations may be substantially recessed into the surface of the tool, whereby the tool surface is stepped.

[0013] In an embodiment of the above system, at least some the striations may comprise a plurality of projections spaced equidistantly apart about the tool.

[0014] In an embodiment of the above system, the tool may comprise a combination of the above striations.

[0015] These specific geometries all provide respective material processing functionalities to the tool and, correspondingly, to the system of the invention in which it is used. For instance, peripheral striations with a substantially square, concave or convex section are particularly suitable for dispersion and encapsulation, wherein each distinct type may be best suitable for one or more respective, relevant materials. Striations with a plurality of projections are particularly suitable for reducing particulate size and/or homogenously mixing one or more materials.

[0016] In an embodiment of the above system, the chamber may comprise a third interstitial portion located between the first and second portions in use. In a variant of this embodiment, the third interstitial portion may have a substantially annular shape.

[0017] These configurations advantageously lend a modular character to the chamber of the system, so that the first and second portions thereof may accommodate a larger tool, again for a specific processing requirement.

[0018] In an embodiment of the above system, the second portion may have a substantially hemispherical outer surface corresponding substantially to the hemispherical chamber volume provided by the second portion.

[0019] In an embodiment of the above system, the outlet may be located at a substantially central aperture of the second partition, co-axially with the shaft.

[0020] This configuration advantageously allows the processed material to exit the chamber of the system substantially at the level of the chamber at which its contents have the least internal velocity or displacement.

[0021] According to another aspect of the present invention, there is also provided a method of reducing the particulate size of a material with any of the embodiments of the above, the method comprising the steps of locating a plurality of grinding beads within the chamber; driving the shaft; and feeding material through the inlet into the chamber, so that a volume of material fed, added to the volume of grinding beads and to the volume of the tool, equals the total volume of the chamber.

[0022] In an embodiment of the above method, wherein the tool comprises a plurality of peripheral striations substantially parallel to one another and substantially perpendicular to the shaft, the method may comprise the further step of mixing the material homogeneously.

[0023] In an embodiment of the above method, wherein the tool has comprises a plurality of peripheral striations substantially parallel to one another and substantially perpendicular to the shaft, the method may comprise the further step of encapsulating the material.

[0024] In an embodiment of the above method, wherein the chamber comprises a second inlet, comprising the further step of feeding a second material through the second inlet.

[0025] In a variant of this embodiment, either of the materials may be a solid, a liquid, in a gaseous phase, or any combination thereof.

[0026] In a variant of these embodiments, the first and second materials may have different viscosities and/or densities relative to one another.

[0027] Other aspects are as set out in the claims herein.

Brief Description of the Drawings

[0028] For a better understanding of the invention and to show how the same may be carried into effect, there will now be described by way of example only, specific embodiments, methods and processes according to the present invention with reference to the accompanying drawings in which: Figure 1 is an exploded side view of an embodiment of a chamber according to the invention, including first and second portions; Figure 2A is a perspective view of both the outer and inner ends of a first portion of the chamber of Figure 1; Figure 2B is a perspective view of the outer end of Figure 2A fitted with a hopper; Figure 2C shows exploded orthogonal views of side and top aspects of the outer end of Figure 2B; Figure 3A shows exploded orthogonal views of side and front aspects of a second portion of the chamber of Figure 1; Figure 3B is a perspective view of an outer end of the second portion of Figures 1 and 3A; Figure 4 shows both a perspective view and exploded orthogonal views of side and front aspects of an intermediary portion for a modular chamber as shown in Figures 1 to 3; Figure 5 is a perspective view of a first embodiment of a substantially spherical tool for use within the chamber of Figures 1 to 4; Figure 6 is a side view of a second embodiment of a substantially spherical tool for use within the chamber of Figures 1 to 4 Figure 7 is a perspective view of a third embodiment of a substantially spherical tool for use within the chamber of Figures 1 to 4; Figure 8A is a perspective view of a fourth embodiment of a substantially spherical tool for use within the chamber of Figures 1 to 4; Figure 8B is an exploded orthogonal view of a side aspect of the spherical tool of Figure 8A; Figure 9A is a perspective view of a fifth embodiment of a substantially spherical tool for use within the chamber of Figures ito 4; and Figure 9B is an orthogonal view of a co-axial aspect of the spherical tool of Figure 9A.

Detailed Descriøtion of the Embodiments [0029] There will now be described by way of example a specific mode contemplated by the inventors. In the following description numerous specific details are set forth in order to provide a thorough understanding. It will be apparent however, to one skilled in the art, that the present invention may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to

unnecessarily obscure the description.

[0030] With reference to Figures 1 to 3B, a first embodiment of a chamber for use with the system of the invention is shown, suitable for processing one or more materials at micrometric and nanometric scales, in a variety of ways according to the type of tool located therein in use.

[0031] The chamber 10 comprises a first portion 20, which in this embodiment includes a cylindrical hollow member 21 delimited by a first substantially closed circular end plate 22 and a second substantially open circular end plate 23 opposed and parallel to the first end plate 22. Both the first and second end plates 22, 23 have a same outer diameter and are in co-axial alignment both with one another and relative to the cylindrical hollow member 21.

[0032] The first end plate 22 includes a central through aperture 24 co-axial with a main longitudinal axis of the cylindrical member 21, of a diameter sufficient to accommodate a drive shaft (not shown) for rotating there through. The first end plate 22 further includes an inlet through aperture 25 to which a hopper is secured.

The inlet aperture 25 is off-centred relative to, and located higher than, the central through aperture 24 so that material may be fed there through by at least gravity.

The hopper comprises a funnel 26 disposed substantially perpendicular to the inlet through aperture 25 and pointing upward, and an elbow duct 27 disposed between the funnel 26 and the inlet aperture 25.

[0033] The second end plate 23 defines a mating ring 23 extending from an edge of the inner surface 28 of the cylindrical member 21, perpendicularly to the main longitudinal axis of the cylindrical member 21. The mating ring 23 comprises a plurality of equidistant through-holes 29, which fasteners may engage when the first portion 20 is releasably secured to a second portion 30 of the chamber 10 described hereafter.

[0034] A characteristic of the first portion 20 is that both the inner surface 28, or wall, of the cylindrical member 21 and the width of first end plate 22 substantially perpendicular to the cylindrical member 21, are collectively configured to define a first hemi-spherical volume 31, which is centred relative to the central through aperture 24. Thus, the inner surface 28 of the cylindrical member 21 is shaped as a portion of a sphere, having a maximum diameter substantially at the level of the inner edge of the second end plate 23, tapering uniformly towards the central through aperture 24 of the first end plate 22, which truncates it.

[0035] The chamber 10 next comprises the second portion 30, which in this embodiment includes a hemispherical hollow member 30 delimited by a substantially open circular end plate 33, from which a hemispherical portion 34 extends perpendicularly, and relative to which the hemispherical portion 34 is centred. Both the second end plate 23 of the first portion 20 and the circular end plate 33 of the second portion 30 have a same outer diameter and, in use, are in co-axial alignment both with one another and relative to the cylindrical hollow member 21 and the hemispherical portion 34.

[0036] The open circular end plate 33 defines a mating ring 33 extending from an edge of the inner surface 35 of the hemispherical portion 34, perpendicularly to the main longitudinal axis of the hemispherical hollow member 30. The mating ring 33 again comprises a plurality of equidistant through-holes 29, which fasteners may engage jointly with correspondingly-aligned equidistant through-holes 29 of the mating ring 23 of the first portion 20, when the second portion 30 is being secured to the first portion 20 of the chamber 10.

[0037] The hemispherical portion 34 includes a central through aperture 36 co-axial with the main longitudinal axis of the hemispherical hollow member 30.

The central through aperture 36 is an outlet aperture to which an exhaust is secured. The exhaust comprises a funnel 37 disposed substantially perpendicular to the outlet aperture 36 and pointing downward, and an elbow duct 38 disposed between the funnel 37 and the outlet aperture 36.

[0038] A characteristic of the second portion 30 is that the inner surface 35, or wall, of the hemispherical portion 34 is configured to define a second hemispherical volume 39, which is centred relative to the central through aperture 36, and has a same radius of curvature as the first hemispherical volume 31 of the first portion 20. Thus, the inner surface 35 of the hemispherical hollow member 30 is shaped as a portion of a sphere, having a maximum diameter substantially at the level of the inner edge of the end plate 33, tapering uniformly towards the central through aperture 36 of the hemispherical portion 34, which truncates it. In this embodiment therefore, the respective radius of curvature for the first and second portions 20, 30 is such that both portions define a substantially uniform spherical volume 31, 39 when secured to one another.

[0039] A further characteristic of the second portion 30 is that a portion 301 of the inner surface 35, or wall, of the hemispherical portion 34 corresponding to the central through aperture 36 is configured as a mesh surface 301. The mesh surface 301 is adapted to retain particulate material grinding media which is located within the spherical volume 31, 39 in use, for instance high-density zirconium beads, so that only the processed material(s) may exit the chamber 10 via the outlet 36, and so that the processing action of the system may continue to be performed as a next batch of material(s) is inserted the spherical volume 31, 39 viatheinlet2s.

[0040] Accordingly, when the first and second portions 20, 30 of the chamber are secured to one another in use, the central through aperture 24 of the first end plate 22 of the first portion 20, co-axial with the main longitudinal axis of the cylindrical member 21, is also in co-axial alignment with the mesh surface 301 and central through aperture 36, themselves co-axial with the main longitudinal axis of the hemispherical hollow member 30.

[0041] It will be readily understood by the skilled person that many variations on the above principle of construction for the processing chamber may be envisaged, for instance to accommodate chamber volume requirements and/or geometry or displacement of the tool therein, or for processing several materials in a same operation. For instance, the inventor has considered the adjunction of at least second inlet aperture 25 to the first end plate 22, through which a second material may be fed. Moreover, with reference now to Figure 4, an alternative, modular embodiment of a chamber 10 considers an intermediary, chamber-extending member 40, described herein by way of non-limitative example only.

With reference to the exploded view shown in Figure 1, in this alternative embodiment the intermediary member 40 locates over the spherical tool 100 between the first and second portions 20, 30.

[0042] In this embodiment, the chamber comprises a third intermediate portion 40 for locating between the first and second portions 20, 30 in use. The intermediate member 40 includes a cylindrical hollow member 41 delimited by a first substantially open circular end plate 42 and a second substantially open circular end plate 43 opposed and parallel to the first end plate 42. Both the first and second end plates 42, 43 have a same outer diameter, which is substantially the same as both the second end plate 23 of the first portion 20 and the circular end plate 33 of the second portion 30 such that, in use, all end plates of the three portions 20, 30, 40 are in co-axial alignment with each other.

[0043] Each of the first and second open circular end plates 42, 43 defines a mating ring 42, 43 extending from an edge of the inner surface 44 of the cylindrical hollow member 41, perpendicularly to the main longitudinal axis of the cylindrical hollow member 41. Each mating ring 42, 43 again comprises a plurality of equidistant through-holes 29, which fasteners may engage jointly with correspondingly-aligned equidistant through-holes 29 of, respectively, the mating ring 23 of the first portion 20 and the mating ring of the second portion 30, when all three portions 20, 30, 40 are being secured to one another.

[0044] A characteristic of the intermediate portion 40 is that the inner surface 44, or wall, of the cylindrical member 41 is configured with a concave profile between the opposed end plates 42, 43. By comparison to the hemispherical volumes 31, 39 respectively defined by the first and second portions 20, 30, the concave profile of the intermediate portion 40 defines a third, oblate spheroidal volume. In this embodiment, the respective radius of curvature for the internal surfaces 28, 35, 44 of the first, second and intermediate portions 20, 30, is such that all portions jointly define a substantially uniform spherical volume 31, 45, 39 when secured to one another.

[0045] With reference to Figures 5 to 9, the system of the invention relies on driving a spherical tool 100 within any of the above embodiments of its chamber, into which one or more materials is introduced by the one or more inlets is 25 as a solid, a liquid, in a gaseous phase, or in any combination, moreover with a same or different viscosities and/or densities relative to one another, in order to process the one or more materials into a desired output material, for instance a nanopowder or a suspension containing dispersed nanoparticles. The system thus also includes appropriate means for driving the tool in the required range of rotations per minutes, wherein such driving means may be electric, pneumatic, hydraulic or any suitable equivalent. Such driving means are for instance releasably secured to a shank portion 110 of the tool 100 by a corresponding socket (not shown).

[0046] The tool 100 is generally configured as a substantially spherical tool 100, for location within the substantially spherical volume of the chamber 10 and externally driven through the central aperture 24 of the first portion 10. The tool has a spherical portion 120 with a main surface having an outer diameter in such range as to provide clearance in the range 0,01 mm to 20mm relative to the internal surfaces 28, 35, 44 of the first, second and optional intermediate portions 20, 30, 40. The shank 110 projects from the main surface 120 co-axially with a radius of the spherical portion 120, whereby sliding the shank 110 within the central aperture 24 of the first portion 10 for engagement by an external socket of the driving means effectively positions the spherical portion 120 of the tool 110 centrally within the substantially spherical volume of the chamber 10,. The shank further comprises a safety notch 115, which extends longitudinally over a portion of its length from an extremity 117 of the shank 110 opposed to the spherical portion 120. The skilled reader will readily understand from the present description that dimensional characteristics of the chamber portions and of the tool may vary widely for practical purposes, for instance to vary the processing time, material volume, internal displacement properties and more such variables, without departing from the scope of the present disclosure.

[0047] Several embodiments of a tool 100 are shown in each of Figures 5 to 9B, each for processing one or more materials in a particular manner and/or according to properties of the one or more materials to process. Most such embodiments of the tool 100 comprise peripheral or annular striations 200 along the substantially spherical and smooth surface 120 of the tool 100, as described hereafter.

[0048] With reference to Figure 5 firstly, in this embodiment the tool 100 comprises six striations 200 which are disposed equidistantly relative to one another and relative to the diameter of the spherical portion 120 of the tool. The striations are also disposed parallel to one another and perpendicularly to a main axis of the tool co-axial with the shank portion 110. Each striation 200 has a substantially square cross-section, comprising opposed upper and lower peripheral surfaces 201, 202 extending from the surface 120 of the tool perpendicularly to the main axis of the tool co-axial with the shank portion 110, which end at a peripheral surface 203 parallel with the main axis of the tool co-axial with the shank portion 110. Respective dimensions of the striation surfaces 201, 202, 203 may vary according to the material processing properties required for the tool 100 and may result in asymmetrical striations relative to the equatorial plane of the tool 100, for instance wherein a striation 200a nearer the shank 110 has larger overall dimensions relative to its equatorial opposite 200b.

[0049] With reference to Figure 6 next, in this embodiment the tool 100 comprises twelve striations 200, six of which are disposed equidistantly relative to one another and intermediate the intersection of the shank 110 with the spherical portion 120 and an equatorial section 205 of the spherical portion 120, and the remaining six of which are disposed in a mirrored configuration on the opposed side of the equatorial section 205, and wherein all twelve striations are disposed parallel to one another and perpendicularly to a main axis of the tool co-axial with the shank portion 110. Each striation 200 is implemented by notching the spherical portion 120 peripherally about its axis with a right-angle tool, wherein the resulting v-shaped notch consists of a first surface 206 extending from the surface 120 into the tool perpendicularly to the main axis of the tool co-axial with the shank portion 110, and a second surface 207 extending from the surface 120 into the tool in parallel with the main axis of the tool co-axial with the shank portion 110. The tool surface 120 is effectively stepped transversely to the main axis of the tool 100.

[0050] With reference to Figure 7 next, in this embodiment the tool 100 comprises six striations 200 which are disposed equidistantly relative to one another and relative to the diameter of the spherical portion 120 of the tool. The striations are also disposed parallel to one another and perpendicularly to a main axis of the tool co-axial with the shank portion 110. Each striation 200 has a substantially curved cross-section, of a uniform radius 208 about the spherical portion 120 such that each striation is effectively shaped like a continuous annular bead projecting from the spherical surface 120. Respective dimensions of the striation radii 208 may vary according to the material processing properties required for the tool 100 and may result in asymmetrical striations relative to the equatorial plane of the tool 100, for instance wherein a striation 200c nearer the shank 110 has larger overall dimensions relative to its equatorial opposite 200d.

[0051] With reference to Figures 8A and 8B next, in this embodiment the tool 100 comprises a plurality of apertures 300 profiled according to the direction of rotation 301 of this tool. Each aperture 300 is profiled to taper inwardly into the tool, from a first end 302, which is substantially at the level of the spherical surface 120, towards a second end 303, which is a distance away from the first end 302 in a direction both opposed to the direction of rotation 301 and substantially perpendicular to a main axis of the tool co-axial with the shank portion 110. The second end 303 takes the form of a substantially curved surface 303, such that each aperture 300 is shaped substantially as a teardrop extending away from the direction of rotation 301 and substantially perpendicular to the main axis of the tool co-axial with the shank portion 110. Respective dimensions of the apertures 300 may vary according to the material processing properties required for the tool 100 and may result in asymmetrical apertures 300 relative to the equatorial plane of the tool 100, for instance wherein apertures 300a, 300b nearer the shank 110 have smaller overall dimensions relative to equatorially-opposed apertures 300c, 300d.

Those skilled in the art will readily understand that many permutations of aperture geometries and sizes may be possible without departing conceptually from the

present example.

[0052] With reference to Figures 9A and 9B next, in this embodiment the tool 100 corresponds substantially to the embodiment described with reference to Figure 6, in that it comprises seven striations 200, wherein all seven striations are disposed parallel to one another and perpendicularly to a main axis of the tool co-axial with the shank portion 110, and each striation 200 is implemented by notching the spherical portion 120 peripherally about its axis with a right-angle tool, wherein the resulting v-shaped notch consists of a first surface 206 extending from the surface 120 into the tool perpendicularly to the main axis of the tool co-axial with the shank portion 110, and a second surface 207 extending from the surface into the tool in parallel with the main axis of the tool co-axial with the shank portion 110. The tool surface 120 is effectively stepped transversely to the main axis of the tool 100.

[0053] In this embodiment however, a plurality of fixed projections 400 are implemented on each first surface 206, and are spaced equidistantly relative to one another about the length of each striation 200. Relative to the equatorial plane of the spherical portion 120, which intersects the main axis of the tool co-axial with the shank portion 110 perpendicularly, the projections 400 on first surfaces 206 located between the shank 110 and the equatorial plane project towards the shank and substantially parallel to the main axis; on the opposite side of the equatorial plane, the projections 400 on first surfaces 206 project away from the shank 110 and still substantially parallel to the main axis.

[0054] Each projection 400 takes the form of a substantially symmetrical shape comprising a central rectilinear edge 401 projecting perpendicularly from the surface 206, from which two convex curves 402 extend away, in opposition to one another and each towards a respective edge of the surface 206. The convex curves 402 extend from the central edge 401 by a same length, and a third curved surface 403 extends between their respective ends distal the central edge 401, transversely to the width of the surface 206.

[0055] The striation designs described hereinbefore are intended to assist the simultaneous generation of discrete areas of high and low pressure within the chamber 10, to promote the dispersion and/or processing of the one or more materials therein, and to maximise the distance travelled by the material(s) within the chamber, so as to correspondingly maximise the processing effect performed therein. In particular, a dispersion process with the above system increases the potential for material particles to cover more surface area than pre-processed particles, thus also resulting in increased viscosity of the material.

[0056] In use, the chamber portions 20, 30 are taken apart by releasing fasteners engaged in the mating holes 29 of their respective mating rings 23, 33. A relevant tool 100 is selected for the material or materials at hand and the material processing output required, its shank 110 is slid within the central aperture 24 of the first portion 20, then the mating ring 33 of the second portion 30 is abutted to the corresponding mating ring 23 of the first portion 20, their respective mounting holes 29 aligned, and the fasteners engaged therein for securely fastening the two chamber portions to one another.

[0057] If the operation is intended to reduce the particulate size of a material then, after mating the chamber 10 including the tool 100 to the driving means, a plurality of grinding beads are introduced within the chamber 10 via the inlet 25, and are maintained captive within the chamber 10 by the mesh surface 301. The grinding beads may for instance be made of high-density zirconium. The internal volume remaining within the chamber, apt to accommodate the material to be ground, may be determined by various methods that will be well-known to the skilled person. A simple technique may involve filling the chamber with an inert liquid, and measuring its displacement as the beads are introduced via the inlet 25.

[0058] Thereafter, the tool 100 is driven by an external motive force, for instance provided by an electric, pneumatic or hydraulic engine, at a relatively high rotational speed. A notional operating speed range is 1 to 5000 RPM, however it is will be readily understood by the skilled person that still higher rotational speeds may be used, depending on the material(s), tool variation and/or processing operation considered. One or more materials to be processed are subsequently fed into the chamber 10 via the inlet 25, until a volume of material fed, added to the volume of grinding beads and to the volume of the tool 100, equals the total volume of the chamber 10.

[0059] By way of non-limitative example, for a material particle size of 1mm at the time of its introduction within the chamber 10 via the inlet 25, wherein the chamber has a diameter of 140mm, thus wherein the chamber has a total surface of 88m2, and wherein the tool is driven at a speed of 4,800 rotations per minute, each particle thus undergoes processing over a distance of up to 422,400 meters per minute.

Claims

Claims 1. A system for reducing the particulate size of a material, comprising: a modular chamber having at least first and second portions, wherein each of the first and second portions is releasably connected to the other and the portions collectively define a substantially spherical volume, and wherein the first portion comprises at least one inlet and the second portion comprises at least one outlet; a substantially spherical tool located within the chamber and driven by a shaft through a substantially central aperture of the first portion; and means for driving the shaft.
2. A system according to claim 1, wherein the tool comprises peripheral striations projecting from the substantially smooth surface of the tool, the striations being substantially parallel to one another and substantially perpendicular to the shaft in use.
3. A system according to claim 2, wherein at least some of the peripheral striations have a substantially square section.
4. A system according to claim 2, wherein at least some of the peripheral striations have a substantially convex section.
5. A system according to claim 2, wherein at least some of the peripheral striations have a substantially concave section.
6. A system according to any of claims 2 to 5, wherein at least some the striations are substantially recessed into the surface of the tool, whereby the tool surface is stepped.
7. A system according to claim any of claims 2 to 6, wherein at least some the striations comprise a plurality of projections spaced equidistantly apart about the tool.
8. A system according to any of claims 2 to 7, wherein the tool comprises a variety of striations.
9. A system according to any of claims 2 to 8, wherein the modular chamber comprises a third interstitial portion located between the first and second portions in use.
10. A system according to claim 9, wherein the third interstitial portion has substantially annular shape.
11. A system according to any of claims 1 to 10, wherein the second portion has a substantially hemispherical outer surface corresponding substantially to the hemispherical chamber volume provided by the second portion.
12. A system according to any of claims 2 to 11, wherein the outlet is located at a substantially central aperture of the second partition, co-axially with the shaft.
13. A method of reducing the particulate size of a material with the system of any of claims ito 12, comprising the steps of: locating a plurality of grinding beads within the chamber; driving the shaft; and feeding material through the inlet into the chamber, so that a volume of material fed, added to a volume of the grinding beads and to a volume of the tool, equals the total volume of the chamber.
14. A method according to claim 13, wherein the tool comprises a plurality of peripheral striations substantially parallel to one another and substantially perpendicular to the shaft, comprising the further step of mixing the material homogeneously.
15. A method according to claim 13, wherein the tool has comprises a plurality of peripheral striations substantially parallel to one another and substantially perpendicular to the shaft, comprising the further step of encapsulating the material.
16. A method according to any of claims 13 to 15, wherein the chamber comprises a second inlet, comprising the further step of feeding a second material through the second inlet.
17. A method according to claim 16, wherein either of the materials is a solid, a liquid, in a gaseous phase, or any combination thereof.
18. A method according to claim 17, wherein the first and second materials have different viscosities and/or densities relative to one another.Amendments to the claims have been filed as follows: Claims 1. A system for reducing the particulate size of a material, comprising: a modular chamber having at least first and second portions, wherein each of the first and second portions is releasably connected to the other and the portions collectively define a substantially spherical volume, and wherein the first portion comprises at least one inlet and the second portion comprises at least one outlet; a substantially spherical tool located within the chamber and driven by a shaft through a substantially central aperture of the first portion; and means for driving the shaft; wherein the tool comprises peripheral striations projecting from the substantially smooth surface of the tool, the striations being substantially parallel to one another and substantially perpendicular to the shaft in use.2. A system according to claim 1, wherein at least some of the peripheral striations have a substantially square section.3. A system according to claim 1, wherein at least some of the peripheral striations have a substantially convex section.4. A system according to claim 1, wherein at least some of the peripheral striations have a substantially concave section. 0 *.5. A system according to any of claims 1 to 4, wherein at least some the * striations are substantially recessed into the surface of the tool, whereby the tool *..* surface is stepped. S... S *e.* 6. A system according to claim any of claims 1 to 5, wherein at least some the striations comprise a plurality of projections spaced equidistantly apart about the tool.7. A system according to any of claims 1 to 6, wherein the tool comprises a variety of striations.8. A system according to any of claims 1 to 7, wherein the modular chamber comprises a third interstitial portion located between the first and second portions in use.9. A system according to claim 8, wherein the third interstitial portion has substantially annular shape.10. A system according to any of claims 1 to 9, wherein the second portion has a substantially hemispherical outer surface corresponding substantially to the hemispherical chamber volume provided by the second portion.11. A system according to any of claims I to 10, wherein the outlet is located ata substantially central aperture of the second partition, co-axially with the shaft.12. A method of reducing the particulate size of a material with the system of any of claims 1 to 11, comprising the steps of: locating a plurality of grinding beads within the chamber; driving the shaft; and feeding material through the inlet into the chamber, so that a volume of material fed, added to a volume of the grinding beads and to a volume of the tool, equals the total volume of the chamber.13. A method according to claim 12, wherein the tool comprises a plurality of peripheral striations substantially parallel to one another and substantially perpendicular to the shaft, comprising the further step of mixing the material homogeneously.14. A method according to claim 12, wherein the tool has comprises a plurality *0e*.* of peripheral striations substantially parallel to one another and substantially *°. 30 perpendicular to the shaft, comprising the further step of encapsulating the *:*. material.15. A method according to any of claims 12 to 14, wherein the chamber comprises a second inlet, comprising the further step of feeding a second material through the second inlet. -2316. A method according to claim 15, wherein either of the materials is a solid, a liquid, in a gaseous phase, or any combination thereof.17. A method according to claim 16, wherein the first and second materials have different viscosities and/or densities relative to one another. ** $4 * * * S*5S*** * S... * S S...*54S5* * . * * . . * a. S. *S S S