DRYING APPARATUS AND RELATED METHOD

Abstract

There is provided an apparatus for use in drying a sample of geological material having a substantial moisture content. In one aspect, the apparatus comprises a means for providing a flow of heated fluid, and a means for managing the thermal state of the flow of heated fluid. The means for managing the thermal state of the flow of heated fluid is arranged operable with the means for providing a flow of heated fluid so that exposure of the sample to the flow of heated fluid facilitates a reduction of the moisture content of a portion of the sample while substantially preserving one or more chemical and/or physical properties of the portion.

Claims

1-52. (canceled)

53. A method for drying a sample of geological material having a substantial moisture content, the method comprising: providing a flow of heated fluid for flowing through a passage from an upstream end toward an end downstream thereof, the flow of heated fluid being introduced into a portion of the passage in a tangential manner, and managing a thermal state of the flow of heated fluid so as to facilitate, in a rapid or expeditious manner, a reduction of the moisture content of a portion of the sample of material which becomes exposed to the flow of heated fluid while preserving one or more signature characteristics of the minerology of the portion.

54. The method according to claim 53, wherein the method comprises exposing the portion of the sample of geological material to the flow of heated fluid.

55. The method according to claim 53, wherein the thermal state of the flow of heated fluid is managed in a manner so as to facilitate a reduction of the moisture content of the portion of the portion of the sample to substantially below a predetermined level.

56. The method according to claim 53, wherein the managing of the thermal state of the heated fluid flow is performed so as to facilitate a substantial reduction of the moisture content of the portion of the sample while the temperature of the portion remains substantially below a predetermined temperature level.

57. The method according to claim 53, wherein the method includes facilitating or providing a low pressure region downstream of a fluid heating means so as to, at least in part, facilitate the flow of heated fluid.

58. The method according to claim 53, wherein providing the flow of heated fluid involves introducing a rotational, non-linear, or unsteady component of flow into the flow of heated fluid.

59. The method according to claim 53, wherein the method includes causing or facilitating the modification of the sample portion of material so as to increase its effective surface area, so providing for increased exposure of the sample of material, in its modified form, to the flow of heated fluid for drying purposes.

60. The method according to claim 53, wherein the method includes causing or facilitating repetitious exposure of portion(s) of the sample of material to the flow of heated fluid until sufficiently dry so as to be carried by the heated flow of fluid for collection purposes.

61. The method according to claim 53, wherein managing the thermal state of the flow of heated fluid comprises monitoring one or more physical characteristics of the fluid flow, including one or more of the following: fluid temperature, fluid flow velocity, or fluid pressure.

62. The method according to claim 53, wherein the method includes classifying the collected dried material into specific predetermined size ranges.

63. The method according to claim 53, wherein the temperature of the heated flow of fluid is managed so as to be below about 105 degrees Celsius.

64. The method according to claim 53, wherein the heated flow of fluid is managed so as to reduce the moisture content of the sample portion to below about 1 percent by weight.

65. The method according to claim 53, wherein operation of the method results in providing a disagglomerated or disaggregated free flowing powder.

66. The method according to claim 53, wherein the method comprises drying the material in discrete batches.

67. The method according to claim 53, wherein operation of the method provides from about 100 grams to about 200 grams of dried material in a time period of from about 2 minutes to 5 minutes, or from about 2 minutes to about 3 minutes.

68. The method according to claim 53, wherein the method can be performed at a remote location.

69. The method according to claim 53, wherein the method is part of an overarching method for the extraction and analysis of geological material performed at a remote location.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0169] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

[0170] FIG. 1 shows a schematic perspective of one embodiment arranged in accordance with the principles of the invention;

[0171] FIG. 2 shows a schematic perspective view of the chamber of the embodiment shown in FIG. 1;

[0172] FIG. 3 shows a close up perspective view of a lower region of the chamber of the embodiment shown in FIG. 1 and FIG. 2, sectioned along the longitudinal axis X of the chamber;

[0173] FIG. 4 shows another close up perspective view of a lower region of the embodiment shown in FIG. 1 and FIG. 2;

[0174] FIG. 5 shows a further close up perspective view of a lower region of the chamber of the embodiment shown in FIG. 1 and FIG. 2, sectioned along a plane (a vertical oriented plane in view of the embodiment shown) running through the longitudinal axis A;

[0175] FIG. 6 shows a side view of the lower region of the chamber;

[0176] FIG. 7 shows a top view of the upper region of the chamber;

[0177] FIG. 8 shows a close up perspective view of a lower region of the chamber of the embodiment shown in FIG. 1 and FIG. 2, sectioned along a plane (a horizontal oriented plane in view of the embodiment shown) running through the longitudinal axis A;

[0178] FIG. 9 shows a perspective view of the chamber, sectioned along its longitudinal axis;

[0179] FIG. 10 shows a close up perspective view of an upper region of the chamber of the embodiment shown in FIG. 1 and FIG. 2, sectioned along its longitudinal axis; and

[0180] FIG. 11 shows a schematic perspective view according to another embodiment arranged in accordance with the principles on the invention.

[0181] 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 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. 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.

[0182] 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 principles of the invention to the literal interpretation of the term, but rather as would be understood by the skilled reader. Furthermore, reference to positional descriptions, such as ‘upstream’ and ‘downstream’, 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.

DESCRIPTION OF EMBODIMENTS

[0183] Embodiments described herein may include one or more range of values (eg. size, displacement and field strength etc). A range of values will be understood to include all values within the range, including the values defining the range, and values adjacent to the range which lead to the same or substantially the same outcome as the values immediately adjacent to that value which defines the boundary to the range.

[0184] Other definitions for selected terms used herein may be found within the detailed description and apply throughout. Unless otherwise defined, all other scientific and technical terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the invention belongs.

[0185] FIG. 1 shows schematic perspective view of one embodiment of an apparatus 2 used for drying generally moisture laden (typically in the order of about 30% moisture content) geological material samples as extracted in a natural or ‘raw’ state (often a fine granular sticky clay/mud) from a remote geological drilling site, the drying being performed in a manner which seeks to preserve the minerology of the material sample. The apparatus 2 comprises a chamber 8 which defines a passage into which a sample of geological material to be dried is introduced by way of a feed assembly 11 which is associated with the chamber 8 as shown.

[0186] The apparatus 2 includes a means for providing a heated fluid flow. In this regard, the apparatus 2 includes a fluid distribution assembly 10 configured operable with a heat source 14 (provided in the form of an in-line heating element 54 operably associated with a temperature controller 155) for providing the heated airflow. The fluid distribution assembly 10 comprises a vacuum means configured so as to facilitate a flow of fluid within the passage defined by the chamber 8. In the embodiment shown in the Figures and described herein, the vacuum means is provided in the form of vacuum unit 30 (in at least one prototype embodiment, the vacuum means was provided in the form of a Sonixx 2400W (bagless) cyclonic vacuum unit). The fluid distribution assembly 10 further comprises a fluid mixing assembly 16 provided in the form of a rotating member such as an impeller 20 driven by an electric motor 24. The fluid mixing assembly 16 is configured operable for, at least in part, introducing a rotational component of motion into the heated fluid flow. The impeller 20 is provided at a first end 34 of chamber 8, and arranged so that its axis of rotation is substantially aligned with a longitudinal axis X of the chamber. Thus, in the form shown in the figures, impeller 20 is arranged concentric with chamber 8.

[0187] The apparatus 2 further comprises a means 52 for managing the thermal state of the heated fluid flow which is arranged operable with the fluid distribution assembly 10 for drying the moisture laden material so that exposure of the sample material to the heated air flow facilitates a reduction of the moisture content of a portion of the sample while seeking to preserve one or more chemical and/or physical properties of the portion (ie. seeking to substantially preserve the mineralogy of the sample portion). In this manner, any prospective risk in compromising the integrity of the resulting dried material for subsequent analysis processes is avoided or, at the least, reduced. Operation of the apparatus 2 generally seeks to provide a disagglomerated or disaggregated free flowing powder appropriate for analysis/processing purposes.

[0188] The apparatus 2 also includes a means of disaggregating the input sample material for breaking the sample up into smaller portions (as outlined further below) thereby increasing the effective surface area of the sample for drying purposes. In the embodiment described and shown herein, the impeller 20 (and its fins/protrusions (74)) of the fluid mixing assembly 16 also serves to provide this disaggregation function. It will be appreciated that the disaggregation means may also be configured so as to provide a comminution function if needed. Thus, in this arrangement, the fluid mixing assembly 16 and the means for disaggregation (and/or comminution) of the sample material is provided by the same component (ie. impeller 20 with protrusions 74). In the embodiment shown, the impeller 20 is operable for rotating at a rate between about 15,000 to about 25,000 revolutions per minute, the rate of rotation being operable for at least: (1) promoting or facilitating, at least in part, rotational, non-linear, or unsteady flow of the fluid as it progresses downstream within the chamber 8; and/or (2) engaging with the sample material to be dried for the purpose of modifying the sample for increasing its effective surface area which is exposed to the heated fluid flow. The impeller 20 may be of stainless steel material but could be made from other suitable materials depending on the specific circumstances. It will be readily appreciated that the functions of facilitating the rotational nature of the heated flow, and disaggregation of the sample material could be performed by separate components.

[0189] The apparatus 2 also includes a collection means 300 arranged in fluid communication with the chamber 8 and configured operable for the collection of dried material in an appropriate collection receptacle 310. In the embodiment described herein, the collection means 300 is operably associated with the vacuum unit 30 by way of conduit 320. In this manner, the arrangement is configured such that the vacuum unit 30 facilitates flow of the heated fluid (and the dried sample material) to the collection means 300 where it is ultimately separated (by cyclonic separation).

[0190] As is shown throughout FIGS. 1 to 10, the chamber 8 is provided in cylindrical form (provided in the form of a finite length tube section) having opposite first 34 (upstream) and second 38 (downstream) ends. The first end 34 of the chamber 8 is arranged to locate and house the fluid mixing assembly 16 of the fluid distribution assembly 10. In use, the fluid distribution assembly 10 serves to provide a heated flow of fluid through the chamber 8 in the direction of the second (downstream) end 38. In the embodiment shown, the chamber 8 is provided having a volumetric capacity in the order of about 4,000 cubic centimetres. A volumetric capacity of this order has proven to provide good utility in allowing relatively small amounts of sample material to be dried in the desired manner while maintaining sample integrity, and allowing for portability of the apparatus 2. In this regard, the volumetric capacity of the chamber 8 is configured of a size appropriate for the quantity of the sample material input into the chamber to assist in the management of the thermal state of the flow of heated fluid for drying purposes. The performance of prototype embodiments suggest that the volumetric capacity of the chamber assists, at least in part, in providing a thermal environment which can be managed in order to reduce or avoid the risk of compromising the integrity of the mineralogy of the constituents of the sample when seeking to reduce the drying time. In this regard, the volumetric capacity of the chamber 8 may be configured of a size appropriate for a quantity of the sample material input into the chamber for drying the input sample material for achieving an acceptable level of moisture content in the dried sample material (in the order of below about 1% by weight) within an acceptable period of time (which can be between 2 minutes to 5 minutes).

[0191] The second end 38 of the chamber 8 is arranged so as to be in fluid communication with the vacuum unit 30 by way of conduits 42, 320 configured as shown in FIG. 1. When in use, the vacuum unit 30 serves to, at least in part, assist in encouraging the collection of dried material leaving the chamber 8 (by way of being carried by the fluid flow) in the collection receptacle 310 via the cyclone unit 330. In the embodiment shown, conduit 42 is provided in the form of a hose or tube section which is connected to the second end 38 of the chamber 8 in a substantially concentric manner (relative to the orientation of the longitudinal axis X of the chamber). Similarly, conduit 320 is also provided in the form a hose or tube section arranged between the collection means 300 and the vacuum unit 30. Collection of the dried sample material is by way of cyclonic separation in which the dried material collects within the collection receptacle 310 by passing through the cyclone unit 330 fitted to vortex breaker unit 350. After collection of the dried sample, the dried sample material is transferred/removed through the use of a knife-gate valve 360. The knife-gate valve 360 also serves to provide an airtight seal for the collection receptacle 310 necessary for the function of the cyclone unit 330. In other arrangements, the collection receptacle 310 may be more directly associated (ie. arranged integral) with the vacuum unit 30.

[0192] Thus, the embodiment shown in FIG. 1 employs vacuum unit 30 for establishing the vacuum for creating the inherent flow of fluid through the chamber 8 to the collection means 300. The pressure differential provided by vacuum unit 30 assists with the development of the movement of fluid through the system, while the impeller 20 arrangement serves to encourage or help facilitate the rotational nature of the path of the heated airflow within the chamber 8. The presence of the pressure differential caused by the vacuum unit 30 assists in the carriage and collection of the dried material from the chamber 8 to the collection means 300.

[0193] The desired thermal state of the heated fluid flow may be defined by a thermal profile which is composed of information corresponding to any number of physical characteristic(s)/parameter(s) of the heated fluid flow, such as for example, temperature, pressure, and/or flow velocities at regions of interest along the fluid's flow path.

[0194] The means 52 for managing the thermal state of the heated fluid flow comprises one or more sensor units provided at locations along the flow of the heated fluid in the chamber 8 and/or conduit 42. Such sensor units may, for example, include any one or more suitable temperature sensors, pressure sensors, and/or flow velocity sensors (which could be configured so as to measure the effective or average velocity of the flow, and/or the velocity of any localised eddy flows). It will be appreciated that other sensors may be used to measure other physical characteristics of the environment to determine its real-time thermal state. In this manner, the thermal state of the fluid flow can be monitored for control/management purposes in order to ensure that the mineralogy of the sample material being dried is not compromised for analysis purposes.

[0195] For the embodiment shown in FIG. 1, a temperature sensor provided in the form a thermocouple T1 is provided within the chamber 8 (at the mid-section region of the chamber) and the output data (ie. temperature data) measured/monitored by an operator/user of the apparatus 2. In this manner, while the apparatus 2 is in use, an operator/user observes (165) the data received from the temperature sensor T1 to ensure that the sensed value(s) reflects an acceptable thermal state of the fluid flow for drying purposes. If needed, the operator/user may make an appropriate adjustment (175) so as to alter the thermal state of the heated fluid flow as required. Any such adjustment is made by way of adjusting the operational condition of the in-line heating element 54 by way of its associated temperature controller (155), which could be by increasing the output temperature and/or adjusting the flow velocity of any operable fan unit which might be used to assist movement of the air heated by the in-line heating element 54 (or, for example, adjustment to vacuum unit 30).

[0196] It will be understood that multiple temperature sensors could be monitored by the operator/user. For example, with regard to the arrangement shown in FIG. 11, three thermocouples (T1, T2, and T3) are provided and arranged to measure the temperature at selected locations within the chamber 8: at the lower region, mid-region, and upper-regions of the chamber 8. In at least one prototype embodiment, three temperature sensors were installed at regions: immediately upstream of the impeller 20, at the exit of the chamber 8, and further downstream within conduit 42, each recording about 200° C., 100° C., and 80° C. respectively. It will be appreciated that other measurement sensors could be employed and used to inform a control system (or operator/user) configured to manage the thermal state of the fluid flowing through chamber 8 and/or conduit 42.

[0197] Without being bound by results obtained by testing using preliminary prototype embodiments, the temperature sensor(s) may be monitored (manually or otherwise) to ensure that the temperature of the heated fluid in the chamber 8 remains substantially within the range of between about 90 to about 105 degrees Celsius during operation. It has been observed that favourable drying results occur when the temperature within the chamber 8 remains about 90 degrees Celsius. It will be appreciated that temperature variations are likely to occur during operation; for example, the temperature of the environment is likely to fall as moist sample material is introduced into the chamber 8, and will recover (or rise) as the input material begins to dry. In some situations, lower temperatures might be preferable/suitable for achieving acceptable drying rates and resulting form (of the dried material, eg. disaggregated or disagglomerated free flowing powder) depending the circumstances to hand.

[0198] It will be appreciated that as the level of sophistication of the monitoring/control of the thermal environment increases, the management of the thermal state of the fluid flow could be executed in a substantially autonomous manner. In such an embodiment, the means 52 for managing the thermal state of the heated fluid flow may comprise a thermal management unit 150 (see FIG. 11) arranged for monitoring and/or controlling the thermal state of the fluid within the chamber and/or conduit 42 so that drying of the material occurs in a manner which serves to reduce or avoid the potential risk of compromising the mineralogy of the constituents of the input material to be dried.

[0199] The thermal management unit 150 may be configured operable for monitoring (180), controlling (185), and/or managing a desirous thermal profile of the heated fluid as it moves along a portion of the flow path from within the chamber 8 to at or near its downstream end where the dried material is collected in the collection receptacle 310. In one embodiment shown in FIG. 11, the thermal management unit 150 is arranged operable for monitoring the temperature of the heated fluid flow at three locations along the flow path within the chamber 8 so that the thermal state of the fluid flow can be managed appropriately.

[0200] The thermal management unit 150 may be configured operable for varying the temperature of the fluid at one or more locations within the chamber 8 in response to monitoring the thermal state or thermal profile of the fluid within the chamber 8. In this manner, the thermal management unit 150 may further comprise temperature controller 155 which is configured operable so as to be capable of varying (185) the output of the heat source 14 (in-line heating element 54). In one arrangement, the temperature controller 155 may be arranged operable for varying the voltage applied or supplied to the electrical heat source 14 (or operation of the in-line heating element 54). It will also be appreciated that the axial position of the impeller 20 can be controlled (adjusted as discussed below) by way of the thermal management unit 150.

[0201] The thermal management unit 150 may also include one or more sensors units placed at locations along the fluid flow path that measure other physical parameters or characteristics of the flow which can be used to assist in managing the thermal environment within chamber 8. Effective/localised pressure and effective/localised flow velocities are examples of additional parameters which could be measured and used to inform any response needed to ensure the conditions remain appropriate for drying the material without risk to the constituent mineralogy of the sample material. Such parameters, along with temperature data, may all assist in informing the thermal management unit 150 of the estimated thermal profile (or thermal state) of the flow of heated fluid so that any response can be implemented if needed. The skilled reader will appreciate that other parameters could also be monitored.

[0202] With reference again to the arrangement shown in FIG. 11, the thermal management unit 150 may be arranged so as to control or inform the rate of introduction of sample material into the system for drying. As foreshadowed previously, it will be appreciated that the quantity and moisture content of the sample material introduced into the chamber 8 will have the effect of modifying the thermal profile of the fluid in the chamber. In a general sense, the effect in this instance is to reduce the net temperature of the fluid in the chamber 8. As the moisture laden sample material begins to dry and exit from the chamber 8, the thermal profile will change by way of the temperature of the fluid increasing. Thus, the rate at which the moisture laden material is introduced into the chamber 8 serves to, at least in part, alter the temperature profile of the fluid in the chamber—which changes can be monitored by the thermal management unit 150.

[0203] Embodiments of the apparatus 2 could be realised where the moisture content of the incoming material to be dried is measured and sent to the thermal management unit 52 for use in determining whether the thermal state of the heated flow of fluid requires adjustment. Any such adjustment can then be implemented at the appropriate time so that the thermal environment within the chamber 8 is maintained for appropriate operation.

[0204] As noted above, control or operation of the thermal management unit 150 may be conducted a number of ways. Monitoring and control of the thermal state of the heated fluid may be carried out manually by way of manual observation and selective adjustment of the necessary parameters as appropriate. However, as noted, the thermal management unit 150 may be configured so as to manage the thermal environment automatically. For example, in cases where the thermal environment is managed automatically, operation of the thermal management unit 150 could be by way of a programmed PCB or computer CPU. User interaction with the latter could be readily achieved by conventional means (ie. direct access with the programmable PCB or computer terminal) or by way of remote access via the internet using, for example, portable hand held devices such as smart phones, tablet computers and the like (which might include any known wireless protocols for connectivity purposes).

[0205] As noted above, the apparatus 2 includes an integrated separation assembly 360 arranged in operable association with the collection means 300 so that dried material can be separated or classified into specific predetermined portions or sizes of material. The collection receptacle 310 can be configured so as to be emptied (for example, automatically or by manual means) at defined or predetermined intervals. In some arrangements, the defined or predetermined intervals can be prescribed by a user. Emptying of the collection receptacle 310 is, for example, for the purposes of analysis and/or archiving. Means for sample splitting (for example, for providing analytical sampling and/or for archiving purposes) can be achieved by use of a cone splitter or tiered riffle splitter, or by other suitable means known to the skilled reader.

[0206] With regard to FIGS. 3 to 6, the heat source 14 fluidly connects with chamber 8 by way of a connecting means such as a manifold 46 attached to a mounting assembly 85 (described below). In the embodiment shown, the heat source 14 is provided in the form of the in-line heating element 54 which, when operable, serves to heat a body of fluid for introduction into the chamber 8.

[0207] The fluid distribution assembly 10 may include a means by which fluid heated by the heat source 14 may be directed, so that it may engage with the fluid mixing assembly 16. To this end, the in-line heating element 54 could be arranged operable with a fan unit to assist in fluid heated by the in-line heating element 54 being directed or blown into the chamber 8 as appropriate.

[0208] The manifold 46 is configured so as to ensure that substantially all air heated by way of the in-line heating element 54 is introduced or injected tangentially into chamber 8. As discussed above, the use of a fan unit with the heat source 14 is not generally required when a vacuum source such as vacuum unit 30 is fluidically connected to the chamber 8 for facilitating fluid movement therethrough. Furthermore, air for heating and introduction into the chamber 8 is preferably processed by way of a filtering means 380 so that air to be heated is appropriately filtered before entering the chamber 8.

[0209] The manifold 46 comprises a conduit portion 60 (see FIG. 5) which attaches to mounting assembly 85, the arrangement configured so as to provide a passage through which heated fluid (heated by way of the in-line heating element 54) can be introduced or injected into the chamber 8. Conduit portion 60 is dimensioned sufficiently so as to accommodate, in a substantially concentric manner about its longitudinal axis A, an outlet region 64 of in-line heating element 54. The skilled reader will appreciate that, in its simplest form, the relative dimensioning and/or fitting of conduit portion 60 and outlet region 64 is appropriate so as to ensure minimal leakage of heated air when introduced into the chamber 8. Manifold 46 is attached to a region of the mounting assembly 85 by bolts 87 (see FIG. 4), however, it will be appreciated that many other types of fastening arrangements could be used.

[0210] In the form shown in the Figures, manifold 46 is positioned upstream of impeller 20. In this arrangement, heated air from the in-line heating element 54 (temperatures of about 200 degrees Celsius were recorded immediately upstream of the impeller 20 in at least one prototype embodiment) is introduced from an upstream side of impeller 20. Furthermore, and with particular reference to FIG. 5, FIG. 6, and FIG. 8, the attachment of manifold 46 to the mounting assembly 85 is arranged so that the passage it provides for the conveyance of the heated fluid is offset from the longitudinal axis X of the chamber 8 by an offset distance ‘d’ (see FIG. 8). In this manner, heated fluid is introduced into chamber 8 in a substantially tangential manner (in a plane substantially transverse to the longitudinal axis X of the chamber 8). The effect of this is to facilitate appropriate mixing/movement of the heated air within the chamber 8 by, at least in part, imparting a component of angular or rotational motion to the heated fluid flow.

[0211] It will therefore be appreciated that the tangential introduction/injection of the heated air serves to assist in inducing a component of rotational motion to the fluid flow as it enters chamber 8. This can be encouraged by the flow of fluid moving substantially adjacent or across the internal wall of chamber 8, so imparting an angular or rotational component of motion into the flow of fluid. This rotational flow is then engaged by the impeller 20 where protrusions 74 act upon the fluid to further encourage and/or promote the generally rotational or unsteady flow through the chamber 8 (as it progresses downstream). The presence of a rotational flow has been found to be advantageous in ensuring sufficient exposure of the sample material introduced into the chamber 8 to the heated stream of air.

[0212] As shown in at least FIG. 3, impeller 20 comprises a base 70 with a plurality of protrusions 74 extending outward from the base in a substantially downstream oriented direction. The protrusions 74 are shaped so as to promote fluid mixing/movement when the impeller 20 rotates and the protrusions engage with the heated fluid. The skilled person will appreciate that one or more of the protrusions 74 could be shaped so as to increase or reduce mixing or engagement with the heated fluid as desired. Protrusions 74 are provided in the form of elongate truncated fins, each regularly spaced about the base 70 and aligned radially from the centre region of the impeller 20.

[0213] Electric motor 24 drives impeller 20 by way of a drive coupling 80, which is configured sufficiently to provide enough space upstream of impeller 20 to allow for incoming heated fluid through manifold 46 (from the in-line heating element 54) from upstream (or below) the impeller 20. It would be appreciated that many different arrangements could be realised for providing an appropriate driving engagement between impeller 20 and motor 24 (which could be direct or indirect in nature). In the embodiment shown, the motor 24 is provided in the form of a router unit 26 (in this instance, a RT 1350 E plunge router from AEG) having handles 28.

[0214] With reference to FIG. 3, the cylindrical section defining the chamber 8 (and the chamber wall 50) is supported by the mounting assembly 85. The mounting assembly 85 comprises a body 90 having an annular flange 95, the flange being dimensioned sufficiently so as to receive end 34 of the chamber 8 therein. A plate 100 is provided about the annular flange 95 and arranged to bear against lip 103 (see FIG. 3) provided in the body 90. The plate 100 is fastened to body 90 by way of mechanical fastening system using a simple nut/bolt arrangement, however, it will be appreciated that any appropriate fastening system known in the art could be employed for this purpose.

[0215] The skilled reader will understand that plate 100 could readily be arranged to be removeably attachable to the body 90 so that the assembly of the chamber 8, mounting assembly 85, and electric motor 24 can be mounted or fastened to a supporting structure as desired, either in a permanent or removable manner. In such arrangements, such assembly could be connected to any desired mounting structure by way of for example plate 100 (ie. plate 100 supporting body 90). In this sense, apparatus 2 is arranged to be portable for use between different geographical locations.

[0216] A recessed region 102 is provided in the body 90 and defined in part by a shaped annular wall 105. With reference to FIG. 3, a portion of the shaped annular wall 105 is provided in the form of a chamfer which serves to define an outwardly (relative to the longitudinal axis X of the chamber 8) oriented linearly sloping surface portion 107 (hereinafter, ‘chamfered’ section).

[0217] The chamfered section 107 of the shaped annular wall 105 is operable with the impeller 20 of the fluid mixing assembly 16 so that the clearance available between the periphery of the impeller 20 and the shaped annular wall 105 may be varied. In this manner, the impeller 20 is arranged to be moveable or translatable in the direction of the longitudinal axis X, so allowing the clearance with the shaped annular wall 105 to be adjustable. This therefore allows the volume and/or velocity of heated fluid passing by the impeller 20 to be varied, and therefore controlled depending on the volume of heated fluid required/desired in order to maintain sufficient flow velocities and/or internal fluid flow stream temperatures in the chamber 8. It will be appreciated that operation of the apparatus 2 can be optimised if needed given that the air flow and the impeller 20 position can be independently variable.

[0218] Thus, positional adjustment of the impeller 20 in the axial direction of the chamber 8 (or height control in the vertical oriented arrangement shown) in association with the shaped annular wall 105 assists in controlling the volume and velocity of heated air available for engaging the impeller 20 following introduction (tangentially) by way of the in-line heating element 54. In this manner, operable association between the impeller 20 and the shaped annular wall 105 by way of positional adjustment serves to provide an upstream annular nozzle arrangement assisting in developing the generally rotational flow of heated fluid through the chamber 8.

[0219] For practical purposes, the flow of air through manifold 46 may be reversed. Reversing the flow of air through the manifold 46 by use of, for example, a “T” or appropriate valve can serve to evacuate chamber 8 and/or the region upstream of the chamber (that adjacent to the impeller 20) of any material that fails to be transferred out of the drying chamber. This is necessary to provide for sample cleaning to maintain sample integrity, minimise carryover, and therefore reduce the risk of contamination of subsequent samples. Additionally, positional adjustment of the impeller 20 can assist for cleaning purposes when seeking to remove any contaminants from the base (eg. recessed region 102) of the chamber 8 and/or the manifold 46.

[0220] Active control/adjustment of the height of the impeller 20 can assist in altering the operational characteristics of the apparatus 2 in real-time if required. In this manner, the thermal state of the heated fluid flow could be controlled as required in order to maintain an acceptable thermal state. The skilled reader will appreciate that technology providing for the automation of the positional adjustment of the impeller 20 could be readily employed to seek to optimise the desired flow characteristics for any material sample type. Furthermore, manual/automated adjustment of the impeller 20 in combination with the shape of the annular wall 105 could realise many different configurations which could serve to advantageously manipulate the flow characteristics of the incoming heated fluid in order to optimise the performance of the apparatus 2. For example, rather than the chamfered section 107 being linear, this section of the shaped annular wall 105 could be curvilinear in nature. Alternatively, the position of the impeller 20 could remain constant and the shape of the annular wall 105 could be arranged to be adjustable. In the embodiment shown in FIG. 11, operational control of the position of the impeller 20 is managed by the thermal management unit 52.

[0221] It will be appreciated that a range of sensors could be used to measure a variety of performance characteristics, the or each sensor being monitored and used to cause or facilitate specific adjustments to ensure the apparatus operates as might be required for drying a specific geological material of interest. For example, temperature and air flow sensors could be provided at various locations throughout the chamber 8, and used to inform the degree of adjustment needed to be made to the position of the impeller 20 to favour a desired operating objective, ie. substantially constant internal operating temperature (for a given geological sample, for example), and/or a predetermined fluid flow velocity at any specific location within the chamber 8.

[0222] The apparatus 2 may comprise or be configured operable with X-ray fluorescence (XRF) and X-ray diffraction (XRD) sensors for analysing dried material. Such sensors may be incorporated within the collection receptacle 310, or could be provided as part of any transport arrangement used to carry dried material from the chamber 8. The skilled person would readily appreciate where such sensors could be provided for advantageous operation.

[0223] The chamber 8 is formed from a material having favourable heat capacity or thermal capacitance characteristics so as to exploit the presence of a thermal mass and minimise temperature variations. In the embodiment shown, the material of chamber 8 is steel having a relatively high heat capacity or thermal capacitance. Thus, moisture variations occurring within the chamber 8 (or at various locations in the flow stream) during operation can be dampened or compensated for relatively quickly and are therefore less likely to compromise the thermal environment within the chamber 8. Similar may also apply to the material from which conduit 42 is provided of.

[0224] In some situations, it may also be advantageous to employ materials having good insulation properties or high thermal conductivity. In this manner, such materials may serve to provide improved cooling capability so as to prevent, at least in part, ‘caking’ of the input material on the chamber interior walls. Furthermore, it may also be necessary to line the interior wall of the chamber 8 with a non-stick, thermally stable material such as for example, polytetrafluoroethylene (Teflon), to reduce material retention in the chamber and maintain sample integrity.

[0225] With reference to FIG. 3, FIG. 4, and FIG. 6, material to be dried is introduced into the chamber 8 by way of the feed assembly 11 which comprises a plunger feeding unit. In the form shown, the feed assembly 11 comprises a feed conduit 12 which is arranged in fluid communication with chamber 8 by way of collar 110 which seats within chamber wall 50. The skilled reader will understand that other arrangements for fluidly connecting the feed conduit 12 to chamber 8 will be known. It will be appreciated that the arrangement of the feed assembly 11 relative to the chamber 8 (ie. position) may vary depending on the specific drying application. The skilled reader will be aware of other arrangements which could be adapted to achieve an equivalent function, such as auger or extrusion arrangements. Thus, various feed mechanisms could be adapted for use to improve the current operational performance of the prototype apparatus described herein. Examples may include manual or automated/continuous feed mechanisms.

[0226] With reference to FIG. 7 and FIG. 10, the second end 38 of the chamber 8 is closed by way of a closure assembly 115. The closure assembly 115 is provided in the form of a closure 120 which serves to provide a sealed fluid connection between conduit 42 and chamber 8. Particularly, closure 120 is of circular form having an annular flange 122 at its periphery which is appropriately dimensioned for receiving the free end (38) of chamber 8. The closure 120 further comprises a circular aperture 125 which provides a recessed seat 130 configured to support a base 137 of a nozzle 135, the nozzle providing a shaped region to which a free end of conduit 42 connects with. The base 137 of nozzle 135 is held in position by way of a retaining washer 140. As with the connection of the feed conduit 12 to chamber 8, the skilled reader will understand that other arrangements for fluidly connecting conduit 42 to chamber 8 for providing a substantially closed thermal environment could be developed.

[0227] In operation, substantially wet granular geological material to be dried is fed into chamber 8 by way of feed conduit 12 of feed assembly 11. Once introduced, the material is subject to the heated and generally rotational fluid flow provided within the chamber 8. In general, particulate having substantial moisture content will tend to gravitate toward the lower end (first end 34) of chamber 8 by way of gravity. As the particulate dries upon being subject to the oncoming heated fluid stream, it lightens in weight and becomes more susceptible to carriage by the moving air flow. Material not sufficiently dry will continue to fall by way of gravity toward the lowermost end 34 of chamber 8. If while continuing to fall the material dries sufficiently, its weight will reduce to the point at which it will be carried by the flow to the collection means 300. If not sufficiently dry, the material will continue to fall.

[0228] Non-sufficiently dry material may ultimately make contact with the impeller 20. In this event, the centripetal forces developed by the impeller 20 as it rotates will serve to cause the still moisture laden material to be directed radially outward from the centre axis of the impeller and toward the periphery (interior wall region) of the chamber 8 where the heated fluid flow engages the protrusions/fins 74 for mixing purposes. Thus, moist material again becomes exposed to the heated fluid flow for drying, where it is likely to be blown downstream (upwards into the chamber 8) by the relatively high flow velocities experienced proximal the periphery of the impeller 20. If not sufficiently dried/disaggregated/comminuted by the reiterated exposure, the material will again fall to the impeller 20, where it will be directed a further time to the periphery of the impeller 20 for another iteration of exposure to the heated fluid flow. It will be appreciated that, depending on the thermal environment desired, some portions of sample material may undergo a number of cycles of exposure to the heated fluid flow (and repeated contact with the impeller 20) before becoming sufficiently dry/disaggregated/comminuted to be susceptible for carriage by the flow to the collection means 300.

[0229] Furthermore, it will be appreciated that contact with the impeller 20 and protrusions 74 by falling material samples serves, at least in part, to break the sample up into smaller portions thereby increasing its effective surface area for drying purposes. In this manner, increasing the effective surface area of the sample portion has the effect of increasing the surface area of the material that is directly exposed to the heated environment, so reducing the drying time.

[0230] Additionally, larger particles or agglomerates may fall by way of gravity. The dryness of the sample material may, in some instances, likely not control whether the sample material falls or not. If the dried sample is sufficiently fine, it will flow through the system whether dry or not, but the rate of drying will be sufficiently high so that the sample material is dry by the time it is collected (or when leaving the chamber 8). Wetter sample material will tend to become agglomerated more readily meaning that larger heavier particles may be less influenced by the air flow.

[0231] Various performance parameters and associated results of a number of prototype tests are described below.

[0232] In one embodiment, the apparatus 2 may be provided in the form of a spin flash dryer arranged for receiving a wet (estimated up to about 30% moisture content) fine grained sticky mud and drying it to less than 1% moisture content within a short period of time (generally within a number of minutes or seconds) without raising the temperature of the material above the point where its mineralogy may change (at about 105 degrees Celsius).

[0233] Some embodiments of the apparatus described herein may find application to the drying of geological materials (soils, and drilling fines from diamond drilling) using a rugged and field portable system appropriate for use in the field at a remote drill site or similar.

[0234] Performance data of at least one test embodiment of the apparatus is as follows: [0235] Impeller (20) rotation about 22,000 revolutions per minute; [0236] 2.5 mm radial clearance between chamber (8) wall and impeller (20); [0237] 98.5 mm diameter spinning disc; [0238] rotor circumferential speed 111 m/s; [0239] air velocity at radial gap 212 m/s; [0240] air velocity in chamber, 0.5 m/s; [0241] air flow 2501 l/m.

[0242] In another prototype embodiment, testing using a meat grinder auger to feed wet material to the chamber (10 minute test run) with accurate dust collection and weighing, resulted in the following data: [0243] Dry solid collected in separator: 94.91 g [0244] Dry solid collected in chamber: 8.32 g [0245] Dry solid collected below disc: 3.18 g [0246] Total dry solid collected: 106.41 g [0247] % of Total in separator: 89.19% [0248] % of Total in chamber: 7.82% [0249] % of Total below disc: 2.99%

[0250] In another prototype embodiment, testing using improved feed control accuracy, a plunger device, 10×10 g samples introduced into air flow chamber (8) in 1 min intervals (ie, a 10 minute feed period), and with 99% of dry solid accounted for, the following data was collected: [0251] Wet sample total: 101.42 g Wet sample (MC): 29.99 g [0252] Weight water: 30.41529 g Weight solid: 71.00471 g [0253] Dry solid collected in separator: 70.06 g [0254] Dry solid collected in chamber: 0.06 g [0255] Dry solid collected below disc: 0.11 g [0256] Total dry solid collected: 70.23 g [0257] % of total in separator: 99.76% [0258] % of total in chamber: 0.09% [0259] % of total below disc: 0.16% [0260] Missing solids: 0.77471 g [0261] Missing %: 1.09% [0262] Wet feed rate: 0.61 kg/hr [0263] Evaporation rate: 0.18 kg/hr [0264] Sample collection rate: 0.42 kg/hr

[0265] In this test, the wet feed rate, evaporation rate ans sample collection rate correspond to 10 grams/minute, 3 grams/minute, and 7 grams/minute respectively.

[0266] Further refinements of prototype embodiments have worked to increase efficiency allowing drying of, for example, in the order of about 150 g of material in about 2 to 3 minutes, with minimal material left remaining in the chamber (eg. <5 g). Such refinements have included favouring use of a plunger unit (over earlier used auger feed units) for introducing the material into the chamber 8 by allowing multiple, finer (eg. in the order or about 1 mm) streams. The plunger unit allows for a known quantity of sample material to be introduced into the chamber 8. In this manner, the size of the portion inserted by way of the plunger unit is balanced appropriately with respect to the size of the chamber 8 so as to ensure that the material inserted can be dried within an acceptable time frame and is of acceptable form (ie. preferably of a disagglomerated or disaggregated free flowing powder).

[0267] Those skilled in the art will appreciate that embodiments of the apparatus 2 described herein are susceptible to variations and modifications other than those specifically described. The invention includes all such variation and modifications. The invention also includes all of the steps, features, formulations and compounds referred to or indicated in the specification, individually or collectively and any and all combinations or any two or more of the steps or features.

[0268] For example, the means of collecting the dried geological sample(s) is an area where improvement of the apparatus could be realised. In practice, the dried particulate may need to travel extended distances in order to be processed. Thus, conduit 42 could be reconfigured depending upon which transport mechanism is to be employed. Relevant pressure differentials and conduit forms are some of the variables which might require consideration if dried particulate needs to be transported across large distances.

[0269] Transport of the dried particulate from the chamber 8 could be adapted to improve system performance. As such, technologies could be employed to improve carriage velocities and volume to the collections means (300). Such systems could be configured to assist with appropriate temperature and pressure regulation of the thermal environment within which dried particulate is subject to during transport to the collection means. Additionally, such systems could be subject to manual or automated control technologies.

[0270] The chamber 8 may be arranged so as to reduce the risk of dried geological sample adhering to the internal surfaces of the chamber 8. In one embodiment, the chamber 8 could be arranged so as to be subject to a cyclical vibration which serves to ‘shake’ the chamber 8 during operation. This physical motion is considered desirable for assisting in the increase in yield of dried sample.

[0271] As noted, various materials or material coatings could be used to coat or line the internal surfaces of any of the internal components (such as for example, the internal surfaces of the chamber 8 and conduit 42, and the external surface of the impeller 20 and its fins 74) with the view to ensuring that dried sample does not inadvertently adhere to the surfaces. As one example, polytetrafluoroethylene (Teflon) was used to good effect to line the interior surface of the chamber 8.

[0272] As is clear from the principal aspects described above, various embodiments of methods for using the apparatus 2 (and prospective variations) can be readily performed for drying geological material. Furthermore, various embodiments of a system configured for use in drying geological material can be developed drawing from the principles of the operation of the invention described herein. Accordingly, such methods and systems are within the scope of the principles of the invention described herein.

[0273] Throughout this specification, and in the claims which follow, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, 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.

[0274] Furthermore, throughout the specification, unless the context requires otherwise, 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.

[0275] Additionally, where the terms “system”, “device”, and “apparatus” are used in the context of the invention, they are to be understood as including reference to any group of functionally related or interacting, interrelated, interdependent or associated components or elements that may be located in proximity to, separate from, integrated with, or discrete from, each other.

[0276] Modifications and variations such as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.