Pressure Screen

FIG. 1 shows an elevational view of the portable pressure screen housing of the instant invention.

FIG. 2 shows a top plan view of the pressure screen housing of FIG. 1.

FIG. 3 shows an elevational view of the second stage treatment apparatus of the instant invention including the swingable cyclone and conduit apparatus.

FIG. 4 shows an elevational view of the system of the instant invention.

FIG. 5 shows a sectional view of the pressure screen housing of FIG. 1 taken along lines 5--5 of FIG. 2.

FIG. 6 shows a cut-away view showing the detail of the pressure screen housing interior taken along lines 6--6 of FIG. 5.

FIG. 7 is a top plan view of the pressure screen housing with the upper half thereof removed.

FIG. 8 shows a rear view of the door means for clearing large particulate matter from the interior of said pressure screen housing.

FIG. 9 is a detailed cut-away showing a potential configuration for sealing the pressurized housing.

FIG. 10 shows a biasing means for closing the upper half of the pressurized housing in sealing engagement atop the lower half of said pressurized housing.

FIG. 11 shows a hinge means for hinging the upper and lower halves of the pressure screen housing together.

FIG. 12 shows a gasket flange connected to the lower half of the pressure screen housing of FIG. 9.

FIG. 13 is a cross-sectional view taken along lines 13--13 of FIG. 6 of the cyclone outrigger construction.

Referring now to the drawings, FIGS. 1 and 2 show the portable pressure screen apparatus, designated generally by the reference numeral 10, to be comprised of a preferably cylindrically shaped housing member 12 comprised of upper and lower relatively hingable halves 14 and 16, respectively. A support frame means 20 is employed to adjustably support pressure screen housing 12 in a generally tilted attitude as best shown in FIG. 1. Tilting housing 12 causes gravity to draw filtered matter within said housing 12 downwardly due to gravity toward door 18, which is selectively openable or closeable when emptying of the interior of pressure screen 10 is needed. The angle of tilt of housing 12 may be adjusted by moving struts 22 and 24 to raise or lower the rear or front, respectively, of housing 12. In FIG. 1, the front of the housing 12 is to the right and the rear is to the left. An aperture at the end of each said strut 22 and 24 may be aligned as desired with any of a plurality of apertures in legs 23 and 25, respectively, of support means 20. Reference numeral 22 o 24 is used to refer to either of the pair of said adjustable struts 22 and 24 associated with either left or right side of housing 12 as best shown in FIG. 6. Hitch member 27 may be employed in association with support means 20 for towing transport of the screening apparatus 10. Preferably, support jacks or other stabilization means 29 are used in connection with pressure screen apparatus 10 so as to provide the necessary degree of stability and safety while the unit is in operation.

As best shown in FIGS. 1, 4 and 5, a slurry S is pumped using pump P from body of water W, such as a lake or the like, to be dredged, through conduit 30 into the interior of pressure screen housing 12. In a typical application, said slurry consists of approximately 20% solids and 80% liquid. Because it is desired to obtain 100% sand in the preferred embodiment, the liquid and larger solids must be removed. To this end, slurry S enters the interior of housing 12 and comes into dissipating contact with a deflector or baffle plate 32. Said plate 32 deflects the flow of slurry S generally downwardly on to filter screen 34 near the front of pressure screen housing 12 so that the slurry S to be filtered will move downwardly, from right to left in FIG. 5, across the entire length of screen 34. In this way, slurry S is exposed to the maximum amount of filtration across the screen 34 as the heavier particulate matter A moves downwardly as a result of gravity and the internal pressure of housing 12 toward collection box 36. Once a sufficient amount of particulate matter A accumulates in box 36, door 18 can be opened through activation of hydraulic cylinders or other opening means 19 connected between box 36 and door 18, and particulate matter A is permitted to fall out of said box 36.

As this clearing operation of matter A takes only a few seconds, the filtering operation can continue uninterrupted.

Screen 34 is generally curved in cross-section as best shown in FIG. 6 and is held in place by supporting ribs 38, which are mounted to lower pressure screen housing half 16.

Deflector plate 32 is preferably perforated so as to allow a portion of slurry S to pass therethrough but while still causing the larger matter A to deflect thereoff onto the upper portion of screen 34 in the vicinity of deflector plate 32.

The filtered slurry S' exits pressure screen housing 12 through an aperture at the bottom thereof connected to discharge conduit 40. Slurry S' travels through conduit 40 under pressure through rotatable coupling 41 and thereafter against gravity to manifold 42 which divides the flow of slurry S' into, in the instant embodiment, a pair of separators 44, commonly known as cyclones or some other separating device. Additional water is extracted from the slurry S' so that the discharge S" from said cyclones is approximately 85% solid, 15% water.

The water extracted from slurry S' in cyclones 44 travels through return conduits 46 into return manifold 47 and is thereafter transferred through return conduit 48 to, preferably, the body of water from which it was required. As is to be appreciated from FIG. 4, the discharge S" of cyclones 44 can be distributed across an area defined by the arc through which the cyclone/conduit apparatus swings. Coupling 41, which is interposed along conduit 40, allows the apparatus comprising the cyclone and conduits to rotate relative to pressure screen housing 12 to distribute an even greater amount of material S" before it must be transported away.

Housing 12 is comprised of upper and lower halves 14 and 16, respectively, which are hinged relative to each other about hinge 52. Cable means 53 may be employed to support upper half 14 relative to lower half 16 when access to the interior of housing 12 is desired, as for routine maintenance procedures.

Housing 12 further comprises a pair of pressure sensing means 54 and 56 associated with upper and lower halves 14 and 16, respectively, of housing 12. As material A builds up within housing 12, and particulate matter clogs screen 34, the pressure above the screen will increase relative to the pressure below the screen. This pressure differential is sensed by sensing means 56. When the pressure differential reaches a predetermined value, hydraulic cylinders 19 are activated, either manually or automatically, to open door 18 and expel filtered material A from housing 12.

As best shown in FIG. 13, conduit 40 and water return conduits 46 are interconnected in truss-like fashion to impart the greatest structural rigidity and strength to the cyclone/conduit apparatus. The conduits 40 and 46 are supported by means of swingable boom means 60 with which is associated a supporting cable arrangement 62. The cyclone 44/conduit 40, 46 arrangement may be moved from side to side to distribute the discharge material S" from cyclones 44. It should be noted that the discharge end 45 of cyclones 44 should be at a predetermined vertical height above the discharge end of conduit 48 in order for said cyclones 44 to function properly, as they work on a syphon principal. To this end, as mentioned above.

Cable securement means such as U-hook 63 of FIG. 13 or the like may be utilized as attachment means between support cable structure 62 and cyclone/conduit structure.

In use, housing 12 is preferably sealed against leakage by means of gaskets 70 connected to L-shaped flange means 72, 74, respectively, continuous lengths of which are connected to upper and lower housing halves 14 and 16. Any suitable sealing means may be utilized, including 0-rings or interfitting channels about housing 12.

As best shown in FIG. 10, upper housing half 14 may be releasably secured to lower housing half 16 by means of any convenient clamping means, such as threaded rod 82 with handle 8 threadably engageable within a female receiving element 83. Threaded rod 82 may be passed through aligned apertures in extensions 84 of flanges 72 and 74 so as to provide for the proper registration of flanges 72 and 74 with gasket 70.

The periphery of the interior of pressure screen housing may be lined with a material 76 having a strong resistance to abrasion. Suitable material might be, for example, but not by way of limitation, a rubber abrasive material.

The instant invention has been shown and described herein in what it is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.