Abstract:
An auto-cleaning marination filter for a poultry injector system including an outer housing having a liquid inlet and outlet, a screen that allows passage of liquids and impedes passage of solid particles, and a wiper surrounded by said screen for removing solid particles attached to the screen by reverse flow of the liquid through a gap in the wiper.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/798,607, entitled “Auto-Cleaning Marination Filter for Injector” and filed on Mar. 15, 2013. The complete disclosure of said provisional patent application is hereby incorporated by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to automated poultry needle injector systems that mechanically pump a brine solution into poultry products using a pump pulling from a brine tank and a bank of needles mounted in an injection head. 
     2. Brief Description of the Related Art 
     Prior art needle injection systems pull a brine solution from a tank by means of a centrifugal pump, and the discharge goes through a series of filters and screens to separate the solid particles from the brine solution before it goes into the injection head. Once the brine gets to the injection head, it flows through a series of needles and from those needles into the product (e.g. poultry carcasses). Not all of the brine stays inside the product. The excess flows through the injector body and back into the brine tank to be filtered and reused. One drawback of the prior art system is that, throughout the process, all of the screens become clogged with solid particles that have been separated from the brine when filtered and the filters lose surface area. This causes a decrease in pressure in the discharge line downstream of the filter and prohibits the injector from injecting product consistently during the full run time shift. The injection percentage will drop after the filter becomes clogged due to running at a lower pressure. Another drawback is that as the standard filters become clogged, an operator has to manually switch from the filter in use to a secondary filter so the previous one can be removed and cleaned prior to being used again. During a normal shift, this can happen many times which requires substantial time and resources to keep the system running correctly. 
     The limitations of the prior art are overcome by the present invention as described below. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is directed to an auto-cleaning filter that has a wiper inside a cylindrical filtering screen to remove solids that accumulate on the internal screen surface and through the screen perforations. The wiper continuously moves along the length of the screen and removes the solids along the entire surface area. By doing this, the screen stays clean and unclogged with particles so the brine can flow freely through it and to the injection head. The solids are flushed out by brine flowing through the filtering screen in an opposite direction of normal flow, which moves the particles through a gap in the wiper. The particles are then moved out of the filter to a rotating cylindrical screen over the brine tank that includes an auger to pass the solids to a waste bin. This keeps the filter continuously free of solid debris so brine can always flow through the filter easily and without restriction. It also eliminates the extra time and resources needed to switch and clean filters throughout the shift. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of the exterior of the auto-cleaning filter of the present invention. 
         FIG. 2  shows a cut-away view of the auto-cleaning filter of the present invention taken along the line A-A of  FIG. 1 . 
         FIG. 3  is a detailed cut-away view of the wiper internal the filter screen of  FIG. 2 . 
         FIG. 4  is a schematic of the complete filter system for the injector using the auto-cleaning filter in-line with the system. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIGS. 1-4 , the preferred embodiments of the present invention may be described. The auto-cleaning filter  19  of the present invention includes an outer filter housing  1  and a filter screen  10 . The outer filter housing  1  and filter screen  10  are preferably cylindrical. The cylindrical filter screen  10  allows the liquid brine to pass through its perforations, but collects any solids against its surface.  FIG. 2  shows a sectional view illustrating the internal components of the auto-cleaning filter  19 . On the inside surface of the cylindrical screen  10  is a wiper  8  that is attached to a tube  2 . The wiper  8  is continuously moved or stroked with the tube  2  to the top of the screen  10  and then with the tube  2  to the bottom of the screen  10  by pneumatic cylinders  4  attached to tube  2  below valve  3 . This cycle is repeated continuously so the wiper  8  is constantly moving inside the cylindrical surface of the screen  10 . 
     The filter  19  has a brine inlet  5  on the bottom of the housing  1  and a brine outlet  7  on the side of the housing  1 . Brine is pumped through the inlet  5  and into the space  12  created between the tube  2  and the screen  10 . The brine mixture then moves through the screen  10  into the space  13  created between the outside surface of the screen  10  and the outer filter housing  1 . As the brine flows through the screen  10 , the solid particles within the brine mixture are trapped on the inner surface of the screen  10  while the liquid flows through the screen  10 . The liquid brine then moves out of the filter  19  through the filter outlet  7  attached to the outer filter housing  1 . 
     The wiper  8  has a top half and a bottom half that are separated slightly to create a gap  9  between them. This gap provides a passage to the inside of the tube  2  on which the wiper  8  is connected. The tube  2  extends out of the filter housing  1 . As shown in  FIG. 2 , a sealed cap  11  is attached to the top of the outer filter housing  1  and receives the tube  2  as it exits the outer filter housing  1 . The cap  11  prevents leakage of brine. At the top of the tube  2 , there is a valve  3  that opens and closes. Opening the valve causes the brine to flow through the screen in the opposite direction (i.e. from outside the screen to inside the screen) as described above. The opposite flow of the brine is only permitted in the area surrounding the gap  9  formed in the wiper. The brine in the space  13  between the outside surface of the screen  10  and the outer filter housing  1  flows through the screen  10  and the gap  9  in the wiper. The brine then moves into the tube  2  and out of an outlet port  6  on the valve  3  on the filter  19 . As this occurs, the reverse flowing brine will clean the solid particles off the inside of the screen  10  and flush them out through the valve outlet port  6 . The valve outlet port  6  is connected to a hose that will transport the brine and the solid mixture back to an open screen  15  where the solids will be carried out by an auger and the brine will be re-used. 
     In operation, the brine inside the filter  19  will always be at a certain system pressure, which will be determined by the requirements of the operation. When the valve  3  on the filter  19  opens, the pressure through the tube  2  and in the gap  9  between the wiper  8  will drop substantially compared to the system pressure. This causes the brine to back flow in this gap  9  area only, thus cleaning a small spot on the filter each time the valve  3  opens. As this is repeated when the wiper is in different locations, the filter screen  10  will stay much cleaner than a standard system without any internal cleaning system. 
       FIG. 4  shows a representative drawing of a complete filter system used to filter the brine on a product injector system. In this system, brine will be pulled from a brine tank  14  into a pump  34  through a pump inlet  31 , and discharged from a pump outlet  32  and into the inlet  5  of the auto-cleaning filter  19 . From there, the brine exits the auto-cleaning filter  19  through the outlet port  7 . The brine may then flow into a backup in-line filter  18 . This is an optional filter to catch any solid particles that may have made it through the auto-cleaning filter. If utilized, the brine will travel into the backup filter  18  through an inlet port  27  on the backup filter  18  and then through an internal screen and out of the outlet port  26  on the backup filter  18 . The backup filter  18  is cleaned manually when clogged, but by using the auto-cleaning filter upstream of it, the cleaning should be minimal. After the brine exits the backup filter  18 , it flows through a valve (not shown) and into the injector head of the injector  16  through an inlet port  24 . The brine flows through the head, enters the injection needles  25  extending downwardly from the head, and is then discharged through the bottom of the needles  25  into the product  33 , such as poultry carcasses, that are on top of a perforated belt  17 . 
     Any excess brine that is not retained in the product  33  will flow through the perforated belt  17  and down into the lower body  20  of the injector  16 . The brine then drains out of the lower body  20  through a drain port  21  and into an open screen solid separating rotary filter  15  through the inlet side  22  of the filter  15 . The open screen solid separating rotary filter  15  has a screen with an internal auger system that rotates to push solids out the discharge end  23  and let the brine fall through the screen and back into the brine tank  14 . This cycle then continues as previously described. 
     The brine mixture that is created as the wiper cleans the screen in the auto-cleaning filter is discharged through the exit port  6  of the auto-cleaning filter. This is reintroduced into the brine system by plumbing this line in with the drain port  21  from the lower injector body  20 . The brine mixture is discharged by the open screen rotary filter  15  where the brine will flow through the filter and back into the brine tank  14  to be reused. 
     The present invention has been described with reference to certain preferred and alternative embodiments that are intended to be exemplary only and not limiting to the full scope of the present invention.