Abstract:
An industrial separator and dewatering plant delivers an influent to an inclined rotating filter belt for filtering out solid matter from the influent. A wash water is sprayed on the return portion of the belt to dislodge residual solid matter captured within the belt. A dewatering portion has an auger screw positioned for receiving the solid matter and the wash water. The auger screw transports the wash water and the solid matter to a compression cage where water is driven out of the solid matter by compression as it exits the plant. Alternately, the solid matter and wash water may be delivered together to a plant exit. Excess wash water is able to drain from the auger screw through a separate drain.

Description:
[0001]    No federally sponsored research or development was used with respect to the apparatus and method herein described, and there is no reference to a sequence listing or table and no computer program listing or compact disc appendix is included herein. 
       BACKGROUND OF THE DISCLOSURE 
       [0002]    This disclosure relates to the field of industrial filtering plants and more particularly to such a plant that uses a continuous filter belt and an auger. Filter belts are often used to filter solid matter from an aqueous mixture. Belts commonly become clogged with the solid matter so that they require occasional or continuous cleaning or reconditioning. Keeping the belt clean is critical to efficient operation and especially for continuous operation. The prior art teaches a variety of ways for ridding filter belts of solid matter. Once the solid matter has been removed from the filter belt it is known, for instance, to mechanically extract fluid via a screw press. Hot water and steam are known to be used to heat and clean filter belts. It is known to use wash nozzles to clean raked-off or screened solid matter. The prior art teaches spraying through a continuous drag-out belt to dislodge debris. It is also known to use compressed air as the primary motive force to clean a moving filter belt. However, the prior art does not provide a solution to preventing effluent from collecting in the bottom of a processing plant. The prior art also does not provide a solution to segregating filtered water from spray-off water. Finally, the prior art also does not provide a solution to possible overflow of water within an auger screw. The present apparatus provides a solution to these difficulties. 
       BRIEF SUMMARY OF THE DISCLOSURE 
       [0003]    The presently described apparatus processes aqueous effluents to extract much of the water content leaving a semi-dry organic solid matter which has value in post processes. The process receives an effluent and first filters it to remove most of its liquid content and then compresses the remaining solid matter to extract much of the remaining water. The filtration step uses a mesh filter belt to capture the solid matter that is within the effluent, and then an auger to press much of the remaining water out of the solid matter. A wash spray is directed onto the back side of the filter belt which washes away solid matter on the front side of the filter belt, and also clears solid matter that is present within pores of the filter belt. In an auguring step, the solid matter and wash spray are compressed, which squeezes out much of the water in the mixture. A free water drain is located at one end of the auger while the solid matter is compressed and moved by the auger in the opposite direction to a compression chamber. Water of the wash spray that is not absorbed by the solid mater in the auger is free to flow above and around the auger&#39;s flights and by gravity flows toward and into the free water drain. By allowing this drainage, a liquid level in the auger is controlled so that the solid matter exiting the dewatering section is able be controlled to meet a specified moisture content. 
         [0004]    An objective of the described apparatus and method is to prevent contamination of the filter belt. 
         [0005]    A further objective is to reduce input energy requirements by eliminating the need for an air blower and air knife common to prior art methods. 
         [0006]    A further objective is to provide sufficient time for gravity drainage of effluents entering the plant. 
         [0007]    A further objective is to provide efficient filter cleaning using relatively little water in a back-spray step. 
         [0008]    Other features and advantages will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the presently described apparatus and method of its use. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0009]    Illustrated in the accompanying drawing is a best mode embodiment of the presently presented plant and its method of use. In such drawing: 
           [0010]      FIG. 1  is an example mechanical schematic of said plant as viewed in a frontal perspective; 
           [0011]      FIG. 2A  is an example mechanical schematic thereof shown in a side perspective view with portions deleted so as to better illustrate interior features; 
           [0012]      FIG. 2B  is an example partial sectional view of a lower portion of a filter belt thereof illustrating a dewatering and filtering process; 
           [0013]      FIG. 3  is an example mechanical schematic thereof shown in a frontal perspective view with portions deleted so as to better illustrate interior features; 
           [0014]      FIG. 4  is an example mechanical schematic thereof shown in a rear elevational view with portions deleted so as to better illustrate interior features; 
           [0015]      FIG. 5  is an example mechanical schematic of a dewatering device thereof shown in an exterior perspective; 
           [0016]      FIG. 6  is an example mechanical schematic perspective view of  FIG. 5  with portions removed to better illustrate interior features; and 
           [0017]      FIG. 7  is an example block diagram illustrating a method of operation of the plant. 
       
    
    
       [0018]    Like reference symbols in the various figures indicate like elements. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0019]      FIG. 1  illustrates an industrial separator and dewatering plant  10  used for processing an effluent  15 A; see  FIG. 7 . Components of plant  10  are supported within and attached externally to a structural enclosure  20 . Locations of a plant: inlet  30  for receiving the effluent  15 A, effluent overflow outlets  40 , wash water pump  50 , outlet  60  for filtered water  15 B, and dewatering device  70  are shown. Techniques for joining in-feed and out-feed conduits to elements  30 ,  40  and  60  are well known in the art. 
         [0020]      FIG. 2A  shows locations of a filter belt  80  supported by a bottom  205  and a top  210  rollers, the filter belt  80  being a fine mesh filter which has an upper belt portion  82  moving above a lower belt portion  84 . Also shown are: filter cavity  85  within which filter belt  80  operates, spray wash nozzle(s)  90 , belt scraper  100 , solid matter collection basin  110 , auger  120 , collection manifold  130 , diverter panel  140 , and catch shelf  150 . Effluent inlet  30  is shown at the left in  FIG. 2A . 
         [0021]      FIG. 2B  shows filter belt  80  as it moves around lower pulley  205  and carries effluent  15 A on upper belt portion  82  upwardly to the left with filtered water  15 B shown dripping through upper belt portion  82  onto diverter pan  170  and flowing through window  172 . A lower dam plate  174  prevents filtered water  15 B from reaching lower pulley  205  and lower belt portion  84 . An upper dam plate  176  is positioned to prevent incoming effluent  15 A, illustrated by a large arrow, from flowing past filter belt  80 . Solid matter  15 C remains on and within upper belt portion  82  and is carried upwardly. 
         [0022]      FIG. 3  shows locations of the diverter pan  170  which, for clarity, is not shown in  FIG. 2A , framework ribs  180  which support upper belt portion  82 , and rubber gasket seals  190  and  192  which constrain filtered water  15 B so it can be secured without being contaminated by solid matter  15 A after passing onto pan  170 . Portions of the enclosure  20 , the filter belt  80 , the filter cavity  85 , and also the wash water pump  50  and the filtered water outlet  60  are also shown in  FIG. 3 . 
         [0023]      FIG. 4  shows locations of a cylindrical wire cage  200 , the top roller  210  which is shown in cross-section, a belt drive  220  for the filter belt  80 , an auger drive  230 , an auger overflow drain  240  for releasing wash water  15 D, a dewatering drain  250  for receiving wash water  15 D and extracted water  15 E, and a compression door  260 .  FIG. 4  also shows: the effluent overflow outlet  40 , filtered water collection basin  130 , filtered water outlets  60 , and belt scraper  100 . 
         [0024]      FIG. 5  shows the dewatering device  70  with its compression door  72  and one of its engaging springs  74 .  FIG. 6  shows interior details of the dewatering device  70  including the wire cage  200 , auger  120 , and dewatering drain  250 . 
         [0025]    Plant  10  separates and dewaters effluent  15 A entering plant  10  at inlet  30 . Effluent  15 A may have a total suspended solids (TSS) in the range of from about 100 to 2,000 mg/L. The effluent  15 A may be collected from a typical municipal sewage system which might have about 300 mg/L TSS. Effluent  15 A may also originate from any other industrial process or source. As shown in  FIG. 7 , trash, garbage and other materials usually found in an effluent drainage may be separated using a pre-filter  75 . Downstream of pre-filter  75  effluent  15 A enters plant  10  at inlet  30  where it encounters diverter panel  140  dropping onto catch shelf  150  whereupon it spills onto filter belt  80  as shown in  FIG. 2B . The diverter panel  140  and catch shelf  150  shown in  FIG. 2  direct the incoming effluent  15 A to filter belt  80  while absorbing most of its incoming kinetic energy. When the inflow of effluent  15 A is in excess of what belt  80  is able to accommodate, it flows out of effluent overflow outlets  40  shown in  FIG. 1  and into an overflow storage tank  85  shown in  FIG. 7  and may be returned to plant  10  later through inlet  30 . The filter belt  80  is made of a filter mesh material of a fineness selected for capturing a desired degree of the TSS carried by effluent  15 A. Once on filter belt  80  effluent  15 A drains by gravity through the top portion  82  of filter belt  80  and, as shown in  FIG. 2 , falls onto diverter pan  170  and from there into alleys  172  and collection manifold  130  to then leave plant  10  via outlets  60  as filtered water  15 B. Gravity drainage continues during the entire time effluent  15 A rides on belt  80 , that is, as belt  80  moves upward. 
         [0026]    Solid matter  15 C is left behind on and in filter belt  80  and comprises between 40-90% of the TSS of the effluent  15 A depending on the type and fineness of the filter material of which filter belt  80  is made. Filter belt  80  moves continuously as an inclined rotating linear filter. Both upper  82  and lower  84  portions of belt  80  may be planar and may move in parallel with each other in opposite directions and over spaced apart top roller  210  and bottom roller  205  ( FIGS. 2A and 2B ). 
         [0027]    As belt  80  moves over top roller  210  some portion of solid matter  15 C may fall into collection basin  110  and therefore into auger screw  120  as best illustrated in  FIG. 2 . As belt  80  starts to move downward a high pressure low volume spray is delivered from one or more nozzles  90  against the inside of the lower belt portion  84  of belt  80  where further solid matter  15 C is washed into collection basin  110 . Subsequently residue of the solid matter  15 C is dislodged by scraper  100  and falls also into collection basin  110 . Solid matter  15 C and wash water  15 D is collected in auger screw  120  and conveyed thereby to the wire cage  200  as best shown in  FIG. 4 , and as described below. Scraper  100  is in position to deflect overspray of wash water  15 D so that it enters collection basin  110 . 
         [0028]    Solid matter  15 C and wash water  15 D are carried by auger screw  120  to the left in  FIG. 4  into wire cage  200  as described above, where wash water  15 D drains into dewatering drain  250 . Solid matter  15 C is compacted by auger screw  120  where most of its water content  15 E is extracted. Brushes  123  attached to, and extending outwardly from the flights of auger screw  120  keep the approximately 1 mm gaps between adjacent wires of the wire cage  200  clear so that extracted water  15 E may flow freely out of wire cage  200  and into dewatering drain  250 . 
         [0029]    Overflow drain  240 , located at the right end of auger screw  120  in  FIG. 4  removes excess wash water  15 D within auger screw  120  when the level of such water rises high enough to flow around auger flights of auger screw  120  which keeps the screw  120  from flooding. 
         [0030]    With the water extraction step described above, solid matter  15 C is converted to a semi-solid consistency which passes out of plant  10  though door  72  when pressure within the wire cage  200  is sufficient to push open door  72  against tension springs  74 . The solid matter  15 C may have a water content of between only 50% and 60%. 
         [0031]    The auger screw  120  is mechanically rotated within auger trough  122  by an electric auger drive motor  230 , as shown in  FIG. 4 . A further drive  220  of belt  80  is also shown in  FIG. 4 . As shown, auger trough  122  is open above auger screw  120  so that solid matter  15 C and wash water  15 D may freely fall into it from belt  80 . Wash water  15 D and extracted water  15 E may be jointly collected into a common manifold outside of plant  10  and may have between 1500 and 5000 mg/L TSS. There are commercial uses for this water because of its high concentration of biological matter. 
         [0032]    Embodiments of the subject apparatus and method have been described herein. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and understanding of this disclosure. Accordingly, other embodiments and approaches are within the scope of the following claims.