Abstract:
Methods and apparatus for removing sediment from a liquid are provided. Pulses of pressurized air are directed into a conduit having an inlet disposed within a first liquid-containing vessel adjacent to (or within) the sediment to cause a slurry of liquid and sediment to flow through the conduit into a second vessel elevated above the first vessel. The slurry of liquid and sediment is allowed to drain from the second vessel into a third vessel that is positioned at an elevation lower than the second vessel. Liquid is drained from the third vessel (to another vessel or elsewhere) as sediment accumulates within the third vessel. The third vessel may be removed when accumulation of sediment therewithin reaches a predetermined amount. The accumulated sediment within the third vessel is removed and the third vessel is returned to service, or another empty vessel may be substituted therefor.

Description:
RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/296,794, filed Jun. 8, 2001, the disclosure of which is incorporated herein by reference in its entirety as if set forth fully herein. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to sediment removal and, more particularly, to methods and apparatus for removing sediment from liquid.  
         BACKGROUND OF THE INVENTION  
         [0003]    Abrasive jet cutting machines are used in many industries for machining various types of products and materials. An abrasive jet cutting machine mixes abrasive material, such as garnet, with high pressure fluid (e.g., water) flowing at a high rate of speed. After a machining operation, the abrasive fluid typically accumulates in a catcher tank where the abrasive material settles to the bottom. Over time, the amount of abrasive material in the catcher tank builds up and must be removed. Removing the abrasive material by conventional methods such as manual shoveling or vacuum suction typically involves shutting the jet cutting machine down, which may be economically undesirable.  
           [0004]    U.S. Pat. Nos. 4,872,975 (the &#39;975 patent) and 5,979,663 (the &#39;663 patent) describe methods for continuously separating and recovering abrasive material without requiring that the jet cutting equipment be shut down. The method proposed by the &#39;975 patent involves separating abrasive material from a slurry via a centrifugal pump and settling tank. The centrifugal pump separates some of the abrasive from the slurry via centrifugal force and the settling tank is used to separate the remaining abrasive material. Unfortunately, centrifugal pumps are generally not recognized as being reliable when handling abrasive materials. Centrifugal pumps may be susceptible to wear and clogging in the presence of abrasive materials, which may require significant and costly maintenance.  
           [0005]    The &#39;663 patent describes a method for recovering garnet using a diaphragm pump and coarse filter. Although generally recognized as being more effective at handling solids than centrifugal pumps, diaphragm pumps may also be susceptible to wear and clogging in the presence of abrasive material, which may require significant and costly maintenance.  
           [0006]    International Pat. App. Nos. WO 99/55492 and WO 01/14102 describe respective methods of using gas bubbles injected into an arrangement of conduits to move a slurry mixture of garnet and water into a settling container. Unfortunately, the proposed arrangements of conduits is somewhat complex, and utilizes multiple horizontal runs and elbows which can become obstructed with abrasive material. Typically, a back-flushing operation is required to remove clogs from the conduit.  
           [0007]    The principal of using compressed air bubbles to lift water from a well or other source is well documented (e.g., see Section  4 - 4  of US Army Field Manual FM 5-484 dated Mar. 8, 1994).  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention utilizes a system of controlled air pulses and a passive collection system to continuously remove solids and other types of materials (e.g., sediment) that have settled to the bottom of a vessel (e.g., a waterjet catcher tank) or other liquidcontaining basin. Embodiments of the present invention can overcome the limitations of prior art methods for removing abrasive material described above by eliminating the need for centrifugal or diaphragm pumps and horizontal conduits, valves and tank penetrations.  
           [0009]    Embodiments of the present invention utilize controlled pulses of pressurized air into a single extraction device or multiple extraction devices for conveying a slurry of fluid and sediment (e.g., garnet/abrasive material) to one or more holding and/or settling reservoirs. The garnet/abrasive material can be emptied from the reservoir or recycled using various methods. Embodiments of the present invention may require no moving parts that are exposed to abrasive material flow. Moreover, centrifugal or diaphragm pumps are not required, thereby reducing equipment down time and maintenance requirements.  
           [0010]    According to embodiments of the present invention, an apparatus for removing sediment (e.g., abrasive material such as garnet) from a liquid (e.g., water) includes a first vessel disposed at a first elevation, a second vessel disposed at a second elevation that is higher than the first elevation, a third vessel disposed at a third elevation that is lower than the second elevation, and a fourth vessel at fourth elevation that is lower than the third elevation. The first vessel contains a liquid and a layer of sediment therewithin. A first conduit defines a first fluid path between an inlet and an outlet. The first conduit inlet is positioned adjacent to (or within) the layer of sediment and the first conduit outlet is in fluid communication with the second vessel.  
           [0011]    According to embodiments of the present invention, a penetration stop may be secured to the first conduit and may be utilized to limit how far the first conduit inlet extends into the layer of sediment. According to embodiments of the present invention, the penetration stop rests on top of the sediment in the first vessel.  
           [0012]    An air source directs pulses of pressurized air into the first conduit to cause a slurry of liquid and sediment to flow through the first conduit into the second vessel. A second conduit defines a second fluid path between an inlet in fluid communication with the second vessel and an outlet in fluid communication with the third vessel. The second conduit is configured to drain a slurry of liquid and sediment from the second vessel into the third vessel.  
           [0013]    The fourth vessel is configured to receive liquid from the third vessel. A third conduit defines a third fluid path between an inlet in fluid communication with the third vessel and an outlet in fluid communication with the fourth vessel. The third conduit is configured to drain liquid from the third vessel into the fourth vessel as sediment accumulates within the third vessel. A fourth conduit defines a fourth fluid path between an inlet in fluid communication with the fourth vessel and an outlet in fluid communication with the first vessel. The fourth conduit is configured to drain liquid from the fourth vessel into the first vessel.  
           [0014]    A fifth conduit defines a fifth fluid path between an inlet in fluid communication with the second vessel and an outlet in fluid communication with the first vessel. The fifth conduit serves as a pressure relief conduit for the second vessel.  
           [0015]    According to embodiments of the present invention, the first conduit is a vertically-oriented, elongated tube having an inlet on one end and an outlet on the opposite end. The outlet is in fluid communication with the second vessel that is elevated above the first vessel. The elongated tube may be movably secured within the first vessel. For example, the elongated tube may be moved manually, or may be configured to move automatically.  
           [0016]    According to embodiments of the present invention, the first vessel may include one or more pairs of generally horizontal slats that extend across the first vessel from one side to an opposite side thereof. The slats in each pair are preferably spaced apart so as to form a slot. The elongated tube may be moved periodically along the slot either manually or automatically.  
           [0017]    According to embodiments of the present invention, one of the slats extending across the first vessel may include a first set of ratchet teeth disposed on an upper surface thereof. A support member for movably securing the elongated tube within the first vessel may include a second set of ratchet teeth that are configured to matingly engage with the first set of ratchet teeth. Vibration of the first conduit caused by pulsed air flow through the first conduit causes the second set of ratchet teeth to move along the first set of ratchet teeth at a predetermined speed. Accordingly, the elongated tube may be configured to move along a predetermined direction automatically.  
           [0018]    The first conduit inlet may include one or more nozzles having various shapes, sizes and configurations. According to embodiments of the present invention, a nozzle assembly is provided that is in fluid communication with the first conduit inlet. The nozzle assembly includes a body, a plurality of circumferentially spaced-apart apertures formed within the body, and a plurality of passageways, wherein each passageway is in fluid communication with a respective aperture and with the first conduit fluid path. The nozzle assembly configuration is designed to create a vortex within the first conduit inlet which can facilitate sediment removal and can reduce the possibility of clogging.  
           [0019]    According to embodiments of the present invention, a portion of one or more of the various conduits and vessels may be transparent such that flow therethrough and/or therein can be observed.  
           [0020]    According to embodiments of the present invention, a sixth conduit may be provided to prevent clogging of the first conduit inlet. The sixth conduit includes an outlet positioned adjacent to the first conduit inlet and is configured to deliver pressurized fluid and/or air adjacent the first conduit inlet.  
           [0021]    According to embodiments of the present invention, an apparatus for removing sediment contained within a volume of liquid is provided. Apparatus includes a vessel comprising an inlet and an outlet; an elongated, substantially linear first conduit comprising an inlet and an outlet, wherein the first conduit inlet is configured to be positioned adjacent to (or within) a layer of sediment within a volume of liquid, and wherein the first conduit outlet is in fluid communication with the vessel via the vessel inlet; an air source that is configured to direct pulses of pressurized air into the first conduit to draw a slurry of liquid and sediment through the first conduit and into the vessel; and a second conduit in fluid communication with the vessel via the vessel outlet, wherein the second conduit is configured to drain a slurry of liquid and sediment from the vessel.  
           [0022]    According to embodiments of the present invention, a method for removing sediment (e.g., abrasive material such as garnet) from a liquid (e.g., water) contained within a first vessel includes the following steps: directing pulses of pressurized air into a conduit having an inlet disposed within the first vessel adjacent to (or within) the sediment to cause a slurry of liquid and sediment to flow through the conduit into a second vessel elevated above the first vessel, draining the slurry of liquid and sediment from the second vessel into a third vessel that is positioned at an elevation lower than the second vessel, and draining liquid from the third vessel (to another vessel or elsewhere) as sediment accumulates within the third vessel. The third vessel may be removed when accumulation of sediment therewithin reaches a predetermined amount. The accumulated sediment within the third vessel is removed and the third vessel is returned to service, or another empty vessel may be substituted therefor.  
           [0023]    According to embodiments of the present invention, the conduit is periodically moved along a predetermined path within the first vessel. Movement may be manual or automatic. For example, the conduit may be moved along the predetermined path in response to the pulses of pressurized air flowing through the conduit.  
           [0024]    According to embodiments of the present invention, pressurized air and/or fluid may be directed into the sediment adjacent to the conduit inlet substantially simultaneously with the step of directing pulses of pressurized air into the conduit.  
           [0025]    An advantage of the present invention is that the slurry flow path upwardly through the conduit is substantially unobstructed and the pulse action of the pressurized air (or other gas) generates a self-priming and self-clearing action. Moreover, the conduit is substantially straight with no bends. As a result, no back-flushing is required. Further, baffles and valves are not required and a catcher tank does not need to be modified to include penetrations for the conduit. Embodiments of the present invention are also designed to be removable, thereby providing accessibility to normally submerged components not readily accessible in prior art devices.  
           [0026]    Embodiments of the present invention are designed to function without the need for an outlet nozzle penetrating a catcher tank or connected piping, which can be susceptible to clogging and may not be readily accessible for cleaning. Eliminating the tank nozzle also may have the benefit that existing catcher tanks need not be modified to include such a nozzle.  
           [0027]    There are other inherent economic benefits in applying embodiments of the present invention to the removal of garnet/abrasive from catcher tanks. By eliminating conventional pumps, hard piping and associated maintenance, the system can be more cost effective due to its simplicity and power consumption efficiency.  
           [0028]    Embodiments of the present invention are not limited to the removal of abrasive material, such as garnet, from catcher tanks of water jet cutting devices. Other potential applications for embodiments of the present invention include, but are not limited to, pumping sand/water slurry to control erosion, extracting slurry from underground storage tanks, removing sediment from water fountains, removing silt from wells, and removing sediment and other solid materials from various liquid-containing basins. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]    The accompanying drawings, which form a part of the specification, illustrate key embodiments of the present invention. The drawings and description together serve to fully explain the invention.  
         [0030]    [0030]FIG. 1 is a schematic illustration of a sediment removal system according to embodiments of the present invention.  
         [0031]    [0031]FIG. 2 is an enlarged, cutaway side view of the inlet of a slurry extraction tube according to embodiments of the present invention illustrating an adjacent conduit for directing pressurized air/fluid into the sediment adjacent the slurry extraction tube inlet.  
         [0032]    [0032]FIG. 3 is an enlarged, cutaway side view of the inlet of a slurry extraction tube according to embodiments of the present invention illustrating multiple adjacent conduits for directing pressurized air/fluid into the sediment adjacent the slurry extraction tube inlet.  
         [0033]    [0033]FIG. 4 is a side view of the receiving vessel in the sediment removal system of FIG. 1, according to embodiments of the present invention.  
         [0034]    [0034]FIG. 5 is a side view of a support bracket for And supporting a slurry extraction tube in the sediment removal system of FIG. 1, according to embodiments of the present invention.  
         [0035]    [0035]FIG. 6A is an enlarged, partial side view of a nozzle assembly at the slurry extraction tube inlet, according to embodiments of the present invention.  
         [0036]    [0036]FIG. 6B is a bottom view of the nozzle assembly of FIG. 6A taken along lines  6 B- 6 B.  
         [0037]    [0037]FIG. 7 is a plan view of a liquid and sediment containing vessel having a plurality of pairs of adjacent slats forming slots within which slurry extraction tubes according to embodiments of the present invention are movable.  
         [0038]    [0038]FIG. 7A is a partial side view of a slurry extraction tube of FIG. 7 taken along lines  7 A- 7 A.  
         [0039]    [0039]FIG. 8 is a broken plan view of a liquid and sediment containing vessel having a plurality of pairs of adjacent slats forming slots within which slurry extraction tubes according to embodiments of the present invention are movable, and wherein the slurry extraction tubes are configured to move along a predetermined path via respective complimentary sets of ratchet teeth.  
         [0040]    [0040]FIG. 8A is a partial side view of a slurry extraction tube of FIG. 8 taken along lines  8 A- 8 A illustrating ratchet teeth engagement between the slurry extraction tube support member and a vessel slat.  
         [0041]    FIGS.  8 B- 8 D illustrate movement of a respective set of ratchet teeth for the embodiment of FIG. 8.  
         [0042]    [0042]FIG. 9 is a partial side view of a slurry extraction tube having a ballast ball attached thereto, according to embodiments of the present invention.  
         [0043]    [0043]FIG. 10 is an enlarged, cut-away side view of a nozzle assembly at the slurry extraction tube inlet, according to embodiments of the present invention.  
         [0044]    [0044]FIG. 11 is an enlarged, cutaway side view of the inlet of a slurry extraction tube according to embodiments of the present invention illustrating an air conduit extension extending through the slurry extraction tube inlet. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0045]    The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of lines, layers and regions, as well as scale, may be exaggerated for clarity.  
         [0046]    Embodiments of the present invention can provide methods and apparatus for removing sediment from various liquid locations (e.g., tanks, vessels, rivers, streams, etc.). As used herein, the term sediment means any material that settles to the bottom of a liquid and includes, but is not limited to, abrasive material from jet cutting processes, silt, sand, mud, clay, etc. According to a specific embodiment of the present invention, methods and apparatus for removing abrasive material, such as garnet, from catcher tanks of water jet cutting machines will be described herein. However, it is understood that embodiments of the present invention may be utilized to remove various other types of sediments from various liquid environments.  
         [0047]    Embodiments of the present invention preclude the need for conventional pumps and devices that utilize moving parts which may be subjected to corrosion, erosion and clogging in the presence of abrasive material. All parts of a sediment removal system according to embodiments of the present invention that are exposed to an abrasive material are designed to function without any significant wear and without requiring significant maintenance.  
         [0048]    Referring to FIG. 1, a sediment removal system  10  according to embodiments of the present invention is schematically illustrated. The illustrated sediment removal system  10  is configured to remove sediment (in this case, abrasive material) from a catcher tank  12  of a jet cutting machine (not illustrated). The illustrated sediment removal system  10  includes a slurry extraction conduit or tube  14 , an air source and regulator  16  for providing pulses of pressurized air (or other gas or fluid), a second vessel referred to as a receiving vessel  18 , a third vessel referred to as a primary collection tank  20 , and a fourth vessel referred to as a secondary collection tank  22 . The slurry extraction tube  14  defines a fluid path  15  between an inlet  14   a  and an outlet  14   b . The inlet  14   a  is positioned adjacent to (or in) the sediment  50  to be removed and the outlet  14   b  is in fluid communication with the receiving vessel  18 . The slurry extraction tube  14  is designed to be self-priming and self-clearing when positioned adjacent to the abrasive material  50  or when immersed directly into the abrasive material  50  in the catcher tank  12 . The slurry extraction tube  14  conveys an abrasive slurry mixture  50   a  to the receiving vessel  18  via pulses of pressurized air provided and regulated by the air source and regulator  16 . The air source and regulator  16  regulates air pressure, air volume, and air pulse cycle time.  
         [0049]    The linear arrangement of the slurry extraction tube  14  and inlet  14   a  reduces the likelihood of clogging caused by the abrasive material. In addition, a slurry extraction tube  14  may be configured to be movably inserted within various locations of a catcher tank. Although FIG. 1 illustrates a single slurry extraction tube  14 , embodiments of the present invention may utilize multiple slurry extraction tubes as illustrated in FIG. 7. Multiple slurry extraction tubes may be moved individually or collectively within a vessel.  
         [0050]    In operation, pulses of pressurized air (or other gas or fluid) are delivered to the slurry extraction tube  14  via tubing  30  from the air source and regulator  16  to nozzle  32 . Air pulses may be delivered having an exemplary pressure of between 40 psi and 80 psi and in exemplary time intervals of between about 0.5 seconds and 2 seconds. However, embodiments of the present invention may utilize various pressures and time intervals without limitation.  
         [0051]    The slurry extraction tube  14  is inserted within the catcher tank  12  such that the inlet  14   a  is positioned adjacent to (or immersed within) the abrasive material  50  on the bottom of the catcher tank  12 . In the illustrated embodiment of FIG. 2, the nozzle  32  is attached to a penetration stop  42  that limits the distance the inlet  14   a  of the slurry extraction tube  14  can be extended into the abrasive material  50 . Pulses of pressurized air provided into the slurry extraction tube  14  via nozzle  32  force a slurry of water (or other liquid that is in the catcher tank  12 ) and abrasive material  50  into the receiving vessel  18 .  
         [0052]    Air pulses directed into the slurry extraction tube  14  draw an abrasive material slurry upward due to the change in specific gravity within the slurry extraction tube  14 . Applicants have unexpectedly found that using pulsed air is more effective for moving a slurry of abrasive material than is a steady air stream.  
         [0053]    In the illustrated embodiment of FIG. 2, the penetration stop  42  contains a passageway  43  that is in fluid communication with the nozzle  32  and with an aperture  44  in the sleeve inner wall  45  of the penetration stop  42 . Aperture  44  is in fluid communication with an elongated aperture  46  formed within the slurry extraction tube  14 . Accordingly, air flows into the nozzle  32  through the passageway  43  and into the fluid path  15  of the slurry extraction tube  14  via apertures  44  and  46 . Elongated aperture  46  allows the slurry extraction tube  14  to be slidably moved within the penetration stop  42 , while maintaining fluid communication with air flowing through passageway  43 .  
         [0054]    In the illustrated embodiment, the slurry extraction tube  14  is slidably supported within the penetration stop  42 . Accordingly, the extent to which the inlet  14   a  can be inserted into the abrasive material can be controlled by sliding the slurry extraction tube  14  within the penetration stop  42 . Air pulses are provided within the slurry extraction tube  14  as described above via nozzle  32  which is fluid communication with the air source and regulator  16  via air supply conduit  30 .  
         [0055]    According to embodiments of the present invention, the inlet  14   a  of the slurry extraction tube  14  may incorporate one or more nozzles. These nozzles may be removable and changeable and may have various shapes, sizes and configurations. For example, FIGS.  6 A- 6 B illustrate a nozzle assembly according to embodiments of the present invention. The illustrated nozzle assembly includes a plurality of circumferentially spaced-apart apertures  41   a  formed within a body  41  of the nozzle assembly, and a plurality of eccentrically positioned, radially extending passageways  41   b  that are configured to create an agitation zone directly below the slurry extraction tube inlet  14   a . Each passageway  41   b  is in fluid communication with a respective aperture  41   a  and with the first conduit inlet  14   a . This configuration is designed to increase the amount of abrasive material in suspension and, thereby, increase removal of abrasive material. FIG. 6B is a bottom end view of the nozzle assembly of FIG. 6A illustrating the configuration of passageways  41   a . Although illustrated as a single nozzle, it is anticipated that embodiments of the present invention may utilize multiple inlet nozzles at the inlet  14 a. Various inlet nozzle sizes and configurations may be utilized without limitation.  
         [0056]    [0056]FIG. 10 is a partial cut-away view of the nozzle assembly of FIGS.  6 A- 6 B according to embodiments of the present invention and illustrating a slurry extraction tube  14  therein. Air from the air source and regulator  16  is provided via air supply conduit  30  to nozzle  32  and then via air supply conduit extension  30   a  into the slurry extraction tube inlet  14 a. A “duckbill” valve  47  (available from A. C. Hoffman Engineering Inc., 5876 Republic St., Riverside, Calif. 92504) is connected to the end of the air supply conduit extension  30   a  within the slurry extraction tube inlet  14   a  to prevent the ingress of abrasive slurry mixture into the air supply conduit extension  30   a . Duckbill valves are well known to those skilled in the art and need not be described further herein. Moreover, other mechanisms known to those skilled in the art may be utilized to prevent the ingress of abrasive slurry mixture into the air supply conduit extension  30   a.    
         [0057]    [0057]FIG. 11 is an enlarged, cutaway side view of the inlet of a slurry extraction tube  14  according to other embodiments of the present invention. Air from the air source and regulator  16  is provided via air supply conduit  30  to nozzle  32  and then via air supply conduit extension  30   a  into the slurry extraction tube inlet  14   a . A duckbill valve  47  is connected to the end of the air supply conduit extension  30   a  within the slurry extraction tube inlet  14   a  to prevent the ingress of abrasive slurry mixture into the air supply conduit extension  30   a . Other mechanisms known to those skilled in the art may be utilized to prevent the ingress of abrasive slurry mixture into the air supply conduit extension  30   a.    
         [0058]    Referring back to FIG. 1, the abrasive material slurry  50   a  within the receiving vessel  18  flows gravimetrically from the receiving vessel  18  into the primary collection tank  20  via conduit  34 . According to embodiments of the present invention, the receiving vessel  18 , or one or more portions thereof, is formed of transparent material to facilitate visual inspection of its contents. Pressure within the receiving vessel  18  is vented to the catcher tank  12  via a conduit  36 .  
         [0059]    When abrasive material slurry  50   a  flows from the receiving vessel  18  into the primary collection tank  20 , the abrasive material settles to the bottom of the liquid in the primary collection tank  20 . The liquid is drained into the secondary collection tank  22  via an overflow conduit  38  as the abrasive material accumulates in the primary collection tank  20 . The primary collection tank  20 , thus, fills with abrasive material and can be removed from the system  10  and emptied when full. Water in the secondary collection tank  22  is drained back to the catcher tank  12  via conduit  39 .  
         [0060]    According to embodiments of the present invention, one or more of the various conduits  34 , 36 ,  38 ,  39  may be transparent to permit visual inspection of flow therethrough. In addition, one or more of the various conduits  34 , 36 ,  38 ,  39  may be flexible tubing.  
         [0061]    According to embodiments of the present invention illustrated in FIGS.  2 - 3 , one or more optional clearing tubes  60  may be utilized to blow pressurized pulses of gas (e.g., air) and/or liquid (e.g., water) directly into the abrasive material  50  adjacent the inlet  14 a of the slurry extraction tube  14 . If the inlet  14   a  of the slurry extraction tube  14  is extended too far into the abrasive  50 , pressurized liquid and/or gas provided via a clearing tube  60  can clear the inlet  14   a  (including any nozzles utilized with the inlet  14   a ) and can initiate the flow of abrasive slurry upwardly into the slurry extraction tube  14 . Air flow through a clearing tube  60  may be controlled by the air source and regulator  16 .  
         [0062]    [0062]FIG. 3 illustrates two clearing tubes  60  positioned on respective opposite sides of a slurry extraction tube  14 , according to embodiments of the present invention. Each clearing tube  60  may be configured to deliver pressurized gas and/or liquid as described above. Moreover, one clearing tube  60  may be configured to deliver pressurized gas and the other clearing tube  60  may be configured to deliver pressurized liquid.  
         [0063]    The outlet  14   b  of the slurry extraction tube extends upwardly into the receiving vessel  18 . An enlarged side view of the receiving vessel  18  is illustrated in FIG. 4. The receiving vessel  18  is configured to receive the abrasive slurry from the slurry extraction tube outlet  14   b  and then allow the abrasive slurry  50   a  to drain gravimetrically to the primary collection tank  20 . According to embodiments of the present invention, the receiving vessel  18  is transparent or has one or more portions that are formed from transparent material (e.g., clear plastic, glass, etc.) to permit inspection of abrasive slurry flow during operation. The receiving vessel  18  may have various shapes, sizes and configurations according to embodiments of the present invention and is not limited to the illustrated embodiment. Moreover, embodiments of the present invention are not limited to the illustrated shapes and configurations of any of the components of the sediment removal system  10 .  
         [0064]    Referring back to FIG. 1, operations of the illustrated abrasive removal system  10  will now be described. With the inlet  14   a  of the slurry extraction tube  14  inserted into (or adjacent to) the abrasive material  50 , the operation cycle begins as the air source and regulator  16  releases pulses of pressurized air into the nozzle  32  through the supply tube  30 . To generate pulses, the air source and regulator  16  may utilize a commercially available solenoid valve, on-off switch, time delay relay or PLC and a filter regulator, as would be understood by those skilled in the art. It should be understood that pulses of pressurized gas other than air may be utilized according to embodiments of the present invention.  
         [0065]    The abrasive slurry mixture is directed into the receiving vessel  18 . The receiving vessel  18  redirects the abrasive slurry flow to the primary collection tank  20  by gravity through conduit  34 . The primary collection tank  20  receives the abrasive slurry and settling of the abrasive material begins. As water (or other slurry liquid) rises in the primary collection tank  20 , excess water overflows into the secondary collection tank  22  through conduit  38 . The secondary collection tank  22  contains primarily clear water with minor abrasive carry-over which settles to the bottom thereof.  
         [0066]    According to other embodiments of the present invention, the secondary collection tank  22  may be eliminated and water or other slurry fluid may be returned directly to the catcher tank  12  or to another location. Alternatively, multiple additional secondary collection tanks  22  may be utilized.  
         [0067]    The overflow of water in the secondary collection tank  22  is returned to the catcher tank  12  by gravity through conduit  39 . When the primary collection tank  20  is full, or nearly full, of abrasive material, air flow into the slurry extraction tube  14  can be stopped and the primary collection tank  20  can be emptied or replaced with an empty tank.  
         [0068]    According to embodiments of the present invention, the slurry extraction tube  14  may be supported on or within the catcher tank  12  in various ways. For example, as illustrated in FIG. 4, a support bracket  90  may be configured to attach the slurry extraction tube  14  to a side wall of a catcher tank  12  or to a slat or other member extending thereacross.  
         [0069]    Referring to FIGS.  7 - 7 A, a support bracket  91  is configured to support a slurry extraction tube  14  disposed within a slot  92  formed by a pair of spacedapart, adjacent slats  93  that extend across the catcher tank  12 . In the illustrated embodiment, multiple pairs of slats  93  and corresponding slots  92  are provided. A slurry extraction tube  14  is be inserted into the catcher tank  12  through a respective slot  92  and can be moved within the tank  12  as indicated by arrow A, as well as upwardly and downwardly into the contents of the catcher tank.  
         [0070]    Various support devices may be utilized to support slurry extraction tubes within tanks and vessels according to embodiments of the present invention. The present invention is not limited to the illustrated support bracket embodiments.  
         [0071]    In the illustrated embodiment, the plurality of slurry extraction tubes are movable collectively within slots  92  via connectors  94 . However, a plurality of slurry extraction tubes  14  may be moved individually and need not be connected.  
         [0072]    According to additional embodiments of the present invention illustrated in FIGS.  8 - 8 D, slurry extraction tubes  14  may be configured to automatically move within a catcher tank or other vessel. As illustrated in FIGS.  8 - 8 A, each slat  93  includes a set of ratchet teeth  95  on an upper surface  93   a  thereof. The support bracket  92  may include a corresponding complimentary set of ratchet teeth  96  that are configured to matingly engage the ratchet teeth  95  on the slat  93 . Vibration of the slurry extraction tube  14  caused by the pulsing of air therethrough is configured to cause the slurry extraction tube  14  to “walk“ along the slat at a predetermined speed. For example, in FIG. 8B, vibration caused by the pulsed air is not enough to lift the support bracket  91  and slurry extraction tube  14  secured thereto. In FIG. 8C, the air pulses have caused enough vibration to cause the support bracket  91  and slurry extraction tube  14  secured thereto to rise upwardly slightly (indicated by arrow A 1 ). The ratchet teeth configuration causes the support bracket  91  to move in a predetermined direction (indicated by arrow A 2 ) by one tooth (or by multiple teeth depending on the ratchet teeth configuration). The ratchet teeth on the support bracket  91  and slat  93  then reengage in mating relationship as illustrated in FIG. 8D until vibration is sufficient to raise the support bracket  91  again.  
         [0073]    According to another embodiment of the present invention and illustrated in FIG. 9, a ballast ball  100  may be attached to a portion of a slurry extraction tube  14  that is submerged beneath the water level in a catcher tank. The ballast ball  100  is configured to facilitate buoyancy of the slurry extraction tube  14  such that movement of the slurry extraction tube  14  within a liquid requires reduced force.  
         [0074]    The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.