Abstract:
A mining apparatus dust collection component including a vessel to receive and circulate an airflow and an entrained particulate material; said vessel separating said particulate material from airflow by a centrifugal effect said vessel including an inlet and an outlet for said airflow said component including attachment means to attach a detachable bag to said vessel said detachable bag preventing air passing through it. A mining apparatus dust collection system including: at least one inlet associated with a respective drilling unit to draw air and dust into said system from a drill bit when said drilling unit is in use; at least a first stage of dust removal being a mining dust collection component as described connected to at least one of said inlet; a vacuum pump to draw air and dust from said drilling unit. A method of operating a dust collection system said method including the collection of dust particles during a drilling operation passing same to at least one separator being a first stage, the output of the at least one separators being passed to a filtration unit being a second stage, the filtration unit passing filtered air through to a vacuum pump.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to a dust collection system which can be used with a bolting machine. While the discussion below is directed to bolting machines, it will be readily understood that the present invention is applicable to other mining apparatus other than just bolting machines.  
         BACKGROUND OF THE INVENTION  
         [0002]    In recent times, the presence of fine particles in the air in a work environment have been found to cause health problems and difficulties to workers. This has impacted upon the operations of mines and mining companies. In some countries like the USA, laws or regulations limit the amount of air borne silica dust that is permitted to be in the work environment around miners and people engaged in mining operations.  
         SUMMARY OF THE INVENTION  
         [0003]    The present invention provides a mining apparatus dust collection component including a vessel to receive and circulate an airflow and an entrained particulate material; said vessel separating said particulate material from airflow by a centrifugal effect, said vessel including an inlet and an outlet for said airflow said component including attachment means to attach a detachable bag to said vessel said detachable bag preventing air passing through it.  
           [0004]    The detachable bag is preferably sealable after detachment from said vessel.  
           [0005]    The detachable bag can include a zipper to seal said bag after detachment from said vessel.  
           [0006]    The vessel or the bag can include a means to keep said bag in an open condition. The means can be a structure such as a wire frame which sits inside said bag, or it may be the parts of the housing containing the separator to which the outside of the bag can attach.  
           [0007]    The invention also provides a mining apparatus dust collection system including: at least one inlet associated with a respective drilling unit to draw air and dust into said system from a drill bit when said drilling unit is in use; at least a first stage of dust removal being a mining dust collection component as described previously connected to at least one of said inlet; a vacuum pump to draw air and dust from said drilling unit.  
           [0008]    The mining apparatus dust collection system can be such that each dust collection component feeds outgoing air exiting said first stage into a single filter or separation component being a second stage.  
           [0009]    The vacuum pump is preferably downstream of the second stage.  
           [0010]    The at least one inlet preferably has a similar sized opening as provided through said drill unit and a drill bit connected to said drill unit.  
           [0011]    A restrictor or variable restrictor can be provided with communicable passage to said inlet and through which air and entrained particulate material will flow.  
           [0012]    Preferably there is included a third stage of filtration or separation whereby air exiting said vacuum pump passes through a filter before exiting said dust collection system.  
           [0013]    The invention further provides a method of operating a dust collection system said method including the collection of dust particles during a mining operation passing same to at least one separator being a first stage, the output of the at least one separator flowing to a filtration unit being a second stage, the filtration unit passing filtered air through to a vacuum pump.  
           [0014]    Preferably there is included a third stage of filtering or separation downstream of the outlet of the vacuum pump.  
           [0015]    Preferably at least one separator of said first and or said second stage and or said third stage has a door to cover an outlet therefrom whereby when a predetermined operation occurs on the mining apparatus the outlet will open thus depositing any separated particulate onto the ground.  
           [0016]    The emptying operation can be automatically timed to be completed before the next said predetermined operation begins.  
           [0017]    The apparatus can be a bolting apparatus. Said predetermined operation can be the retraction of a temporary roof support. In this case preferably said outlet closes the next time that the temporary roof support is moved so as to re-engage a mine roof.  
           [0018]    Preferably the first and or second stage separators will discharge separated particulate into a sealable container. Alternatively the first or second stage separators can discharge the separated particulate onto the ground. Alternatively a combination of both discharge methods can be used.  
           [0019]    Preferably the absence or rupture of one container prevents a mining operation from occurring. The containers are preferably flexible sealable bags.  
           [0020]    In this specification and claims, where the words “comprising”, “comprised” or words derived therefrom are used, those terms are to be interpreted inclusively rather than exclusively. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    Embodiments of the present invention will now be described, by way of example only by reference to the accompanying drawings in which:  
         [0022]    [0022]FIG. 1 illustrates a plan view of the arrangements of components on a bolting machine.  
         [0023]    [0023]FIG. 2 illustrates a side elevation of the apparatus of FIG. 1;  
         [0024]    [0024]FIG. 3 illustrates a perspective view of a cyclone battery;  
         [0025]    [0025]FIG. 4 illustrates a front elevation of the apparatus of FIG. 3;  
         [0026]    [0026]FIG. 5 illustrates a plan view of the apparatus of FIG. 3;  
         [0027]    [0027]FIG. 6 illustrates a side view of the apparatus of FIG. 3;  
         [0028]    [0028]FIG. 7 illustrates a plan view of a wet scrubber assembly;  
         [0029]    [0029]FIG. 8 illustrates a front elevation showing hidden detail of the apparatus of FIG. 7;  
         [0030]    [0030]FIG. 9 illustrates a perspective view of the apparatus of FIG. 7;  
         [0031]    [0031]FIG. 10 illustrates a side elevation of the apparatus of FIG. 7;  
         [0032]    [0032]FIG. 11 illustrates a perspective view of a two cyclone battery for use with the present invention;  
         [0033]    [0033]FIG. 12 illustrates a right side view of the apparatus of FIG. 11;  
         [0034]    [0034]FIG. 13 illustrates a rear elevation of the apparatus of FIG. 11;  
         [0035]    [0035]FIG. 14 illustrates a plan view of the apparatus of FIG. 11;  
         [0036]    [0036]FIG. 15 illustrates a cross section through the left side of the apparatus of FIG. 14 in the direction of arrows AA;  
         [0037]    [0037]FIG. 16 illustrates a schematic layout of a dust collection system;  
         [0038]    [0038]FIGS. 17, 18 and  19  illustrate a bag which can be used with the cyclone dust collectors of the apparatus of FIGS.  3  to  6  or FIGS.  11  to  15 . 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0039]    Illustrated in FIG. 1 is a mobile bolting apparatus such as that described in co-pending application PCT/AU00/00686 filed on Jun. 17, 2000 having International Publication Date of Dec. 28, 2000. The specification and drawings of which is incorporated herein by reference.  
         [0040]    The illustration in FIG. 1 shows the main features of the bolting machine in a general layout view showing the placement of equipment and some of the major features of the bolting machine.  
         [0041]    The bolting machine  10  has a dust collection system  12  located at the rear of the vehicle; three wheels being front wheels  14  and a rear steering wheel  16 ; storage pods  18  located around the middle of the vehicle the front and rear wheels  14  and  16  being extendable and retractable relative to the vehicle frame or chassis; a canopies  20  and  21  over the work area for the protection operators; a line of bolting rigs  22  with the outboard rigs being extendible from a tramming position as illustrated on the left side of machine  10  to a fully extended position outside the tramming width as illustrated on the right side of the machine  10 .  
         [0042]    Centrally positioned and at the forward end of the vehicle is a canopy support structure or lemniscate linkage  24  to which is pivotally mounted a temporary roof support structure  26  which carries the temporary roof support  28 . Also at the front of the vehicle are four bolting rigs  22 . At the rear of the machine  10  is a cable reel  29 , a starter control box  30 , and an electric motor  32  with two driven hydraulic pumps  34  and  36  to drive the dust collection system  12  and or other hydraulically driven components on the mining apparatus or vehicle.  
         [0043]    As illustrated in FIGS. 1 and 16, the dust collection system generally designated by the numeral  12  includes a battery  12 A of four cyclonic separators. The individual cyclonic separators  12 B,  12 C and  12 D and  12 E have their inlets  50  connected to the drill units  22  so as to draw through hollow drill bits  308  (see FIG. 16) air and dust which results from that drilling process. The hoses are not illustrated which connect the inlets  50  to the base drill units  22 .  
         [0044]    Cyclonic separators  12 B through to  12 E are illustrated in more detail in FIGS.  3  to  6 . Each cyclonic separator has a tangentially located inlet  50  which forces incoming air into a spiral path down the separator tube  52 . Particulate material separates from the spiralling air stream by a centrifugal effect. Separated particulate material will fall through outlet  54  into the chamber  56 . At the base of the chamber  56  is an opening  58  which is closable by a door (not illustrated) which can be opened automatically. The air which has separated from the particulate material, is forced to exit the separator by central outlet  57  with a flow path which travels inwardly then upwardly above the cone  59 . The air exiting each of the separators  12 B through to  12 E passes into a single conduit  61  preferably through the left side  64  of the cyclonic separator housing  62 .  
         [0045]    From the cyclonic separator housing  62 , the air and any dust particulate still entrained in the air will pass into a filter  12 F. The filter  12 F is a cartridge filter comprising typically a two stage filter. The filter  12 F is attached to a hydraulic vibrator so as to continually dislodge the build up of particulate material on the cartridge.  
         [0046]    Air from the secondary filter  12 F passes via a conduit  69  to a vacuum pump  12 G powered by a hydraulic motor which obtains its power from one of the hydraulic pumps  34  or  36  attached to the electric motor  32 . The air is drawn through the vacuum pump  12 G and passes via a conduit  67  into a wet scrubber  12 H.  
         [0047]    The wet scrubber  12 H is the last filtration process before the air exits the dust collection system and is released to the mine atmosphere. The wet scrubber is illustrated in more detail in FIGS.  7  through to  10  and consists of a inlet spout  70  to convey the air and any entrained particulate material into the chambers of scrubber  12 H. While this construction of a wet scrubber is detailed, it will be readily understood that other suitably constructed wet scrubbers or filters could be utilised.  
         [0048]    The inlet  70  communicates with the interior of the main scrubber housing  72 .  
         [0049]    The main scrubber housing  72  is of a generally rectangular configuration and consists of a series of baffles which extend from the left hand side through to the right hand side of the housing  72  (that is into the page of FIG. 8). The first, third and fifth baffles  74 ,  76  and  78  define the sealing surfaces to co-operate and seal with covers  80 ,  82 ,  84  and  86  forcing any air entering the housing  72  to pass under the lower edge of each of the baffle  74 ,  76  and  78 . The base of the housing  72  is filled with water which will be filled to a level approximately equivalent to the water line  88  of FIG. 8.  
         [0050]    The lower end of the baffle  74  when the scrubber  12 H is level will be between ½ and 2 inches (12 mm to 50 mm) below the surface of the water line  88 .  
         [0051]    The second, fourth and sixth baffles  90 ,  92  and  94  each extend from close to the base of the housing  72  and terminate below the covers  80 ,  82  and  84 .  
         [0052]    By this construction air passing through inlet  70 , with the housing filled with water to the level indicated by water line  88 , will be forced under the pressure in first chamber  96 , through the water. The air and any entrained particulate material will pass through the water in the direction of arrow  98  into the second chamber  100 . Thence under pressure from chamber  100  to chamber  102  in the direction of arrow  104  repeating the process until all the air has passed through the water three times thereby removing from the air any particulate material. The air will exit the scrubber  12 H via outlet aperture  104  and outlet duct  106 , as clean and dust free as the system is capable of producing.  
         [0053]    The cover plates  80 ,  82 ,  84  and  86  are fitted with a gasket ring or o-ring and have fitting tabs  110  which are engaged by a latching loop  112  of an over-centre latch mechanism  114 . By the latch mechanism  114 , sufficient downward pressure is applied by the covers  80 ,  82 ,  84  and  86  to create an air tight seal via the gasket material.  
         [0054]    The embodiment illustrated in FIGS.  1  through to  10  shows the battery  12 A on one side of the bolting machine. It may be preferable to provide two batteries, one on each side of the bolting machine and to this end a dual cyclonic housing is illustrated in FIGS.  11  through to  15 . The housing  11  through to  15  is constructed similarly to the housing of the previous figures.  
         [0055]    In FIGS.  11  to  15  is illustrated an automatic release mechanism  120  which has a hydraulic cylinder  122  with its piston rod  124  being pivotally connected to bar  126 . The bar  126  which is rotatably connected to the cranks  128  and  130 . The cranks  128  and  130  are connected to the shaft  132  of a butterfly valve (not visible) which closes the outlet in the base of the outlet tube  134 .  
         [0056]    The cyclonic separator of FIGS.  11  through to  15  has a tangential air inlet  136  which receives air from the drilling operations as described previously. The air spirals downward through the cyclonic separator and once the particulate has separated from the air, the air returns back through the centre of the separator and out through the central outlet  138  whereupon the air stream from one separator joins the air stream from another and passes on to the secondary filter  12 F as described above with respect to the previous figures.  
         [0057]    The cyclonic separators of the figures are illustrated as discharging dust onto the mine floor. This discharge process is preferably arranged so that when the temporary roof support is retracted the emptying mechanism  120 , or the door opening mechanism of the apparatus of FIGS.  1  through to  10 , is opened whereby any collected dust during the immediately preceding drilling operation is deposited onto the floor. The cyclonically separated particulate material tends to be comprised of relatively large sized particles as the fine sized particles tend to remain entrained in the cyclonic air stream. The larger sized particles tend to be of lesser risk to mine workers and thus deposition onto the mine floor is thought to have relatively little risk associated with it.  
         [0058]    However, in order to further reduce risk to mine workers, the outlet cylinders attached to the cyclonic separators can be replaced with a flanged outlet  200  as illustrated in FIG. 17. The flanged outlet  200  allows for the attachment of a bag  202 . The bag  202  has a zippered upper periphery  204  and this is opened out enabling the bag  202  to be placed on the flanged outlet  200  as illustrated in FIG. 18. This allows the bag  202  at the upper portions thereof to be clamped by means of an over-centre clamping ring  206  to the cylindrical wall of the flanged outlet  200 . This will provide an air tight seal allowing the dust to fall into the bag  202 .  
         [0059]    Once the bag is full or at a predetermined point in the bolting operation (such as at a change of shift), an operator can remove the bag by unclamping the over-centre clamp  206 , taking off the bag and closing the zipper as illustrated in FIG. 19 by pulling the zip closer  208  from one side of the bag opening to the other. This will allow the bags to be removed from the site without silica dust and other harmful dust particles re-entering the mine atmosphere. Preferably the bags are of a volume equal to approximately 38 liters so that the dust extracted will be a weight which is within the carrying limits of mining personnel, thereby ensuring that the bags can be readily lifted out of the cyclonic separator housings and onto transport to remove them from the mine entry.  
         [0060]    The bag will preferably be of an air tight material, or if the enclosure in which the bag is located is made air tight then a non-air tight material can be used for the bag. Whilst a zipper closing arrangement is described, other closing systems such as VELCRO, clips etc could be used. If a bag of air tight material is used then a frame to hold the bag open may be required.  
         [0061]    Illustrated in FIG. 16 is a schematic diagram of the apparatus described above except that a bag  202  is fitted to each of the cyclonic separators  12 E,  12 D,  12 C and  12 B.  
         [0062]    As schematically illustrated the drill rig  22  has a drill chuck  300  which has a passage  302  therethrough. At a portion of the chuck  300  is a flange  304  which has an annular cylindrical seat  306  upon which a hollow drill rod  308  will sit at the base of the chuck  300 . The base of the chuck  300  via passage  309  communicates with an inlet  311 . The inlet  311  can supply sufficient restriction in the air flow, but if this is not enough, a restrictor or variable restrictor  310  may need to be used. The variable restrictor whilst illustrated in FIG. 16, will be understood as being a preferment.  
         [0063]    When the pump  12 G is activated, air will be drawn through the drill rod  308  the air inlet  311  and the restrictor  310  whereupon it flows through an intermediate manifold  313  and into the cyclonic separators  12 B through to  12 E. The particulate material will fall into the bags  202  whilst the air exits through the top of the cyclonic separator.  
         [0064]    The outlets of the four separators feed into the secondary filter  12 F. The filter  12 F illustrated in FIG. 16 is a filter element which utilises two cartridges represented by the diamond shapes within the bounds of filter  12 F. However, the filter  12 F could instead be of a plate tip filter type which utilises two cartridges or another cyclonic separator which is capable of removing finer particulate. If a cyclonic separator is utilised a bag can be also utilised with the secondary filter  12 F.  
         [0065]    As air exiting the secondary filter  12 F will be largely free of dust particles, the final filter  12 H, such as the wet scrubber described above, will remove further dust particles. However, if desired a further cartridge filter could be utilised. Due to the presence of a primary and secondary stage of filtering the tertiary filter  12 H could be sized to allow approximately six months&#39; life before it requires changing at normal service and maintenance intervals.  
         [0066]    If desired, in addition to the bag  202 , facility can be provided, as described above, for the discharge of particulate material to the mine floor via a butterfly type valve member (such as that indicated by numeral  132  in FIG. 13), as schematically indicated by arrows  203  in FIG. 16. In this way a combination of both facilities can be used. For example the bag  202  can be used until full, and if the workers shift has not ended, the additional particulate material can be deposited on the mine floor to ensure minimal disruption to the shift and productivity.  
         [0067]    One of the features of the dust collection system when bags are utilised, is that the absence of any one bag will mean that the whole dust collection system will not operate. This is because the system will draw air through the separator without a bag and not through the other restrictors and separators. Thus, providing the bags are not located in air tight enclosures, the dust collection system will fail to operate. By simply detecting loss of air flow from the drill rigs, an override switch can be activated by the detector and prevent the drill rigs being operated until such time as the missing bag is fitted. In this way the drill rigs can only be operated in a suitable working environment for the operators.  
         [0068]    If desired, three hydraulic pumps can be provided instead of the two hydraulic pumps  34  and  36  so that two hydraulic pumps power two drilling rigs each, whilst one hydraulic pump could be utilised for the dust collection system and other power requirements.  
         [0069]    If desired the flow path of air in the dust collection systems described above can terminate with a muffler or other sound absorbing apparatus. This can be provided as part of the secondary or tertiary filters such as the wet scrubber  12 H.  
         [0070]    It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.  
         [0071]    The foregoing describes embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto, without departing from the scope of the present invention.