Abstract:
An agricultural cleaning apparatus includes a coarse filter assembly, a coarse filter assembly collection tank disposed to receive intermediate slurry from the coarse filter assembly, and a line disposed to receive the intermediate slurry from the coarse filter assembly collection tank. A coagulant addition device in the line adds coagulant to the intermediate slurry upon receipt of the intermediate slurry from the coarse filter assembly collection tanks. A mixer is in the line, downstream of the coagulant addition device. A flocculant addition device in the line adds flocculant to the intermediate slurry downstream of the mixer. A fine filter assembly receives the intermediate slurry from the line and filters it.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority from U.S. Provisional Patent Application No. 60/717,505 filed Sep. 15, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to cleaning agricultural equipment and treating the run off therefrom.  
         [0004]     2. Related Art  
         [0005]     Agriculture produces waste that requires treatment. In a broad variety of circumstances, beneficial treatment of agricultural waste requires the separation of solids and liquids. These circumstances may include run off from cleaning agricultural facilities such as buildings, treating mixed solid/liquid slurry material pumped from collection pits, and/or treating the run off from agricultural equipment, including tractor trailers used for the transportation of livestock. In some circumstances treated liquids may be released for further use on a farm, or may be released for discharge into a municipal sewer system, as for example in the case of cleaning transportation trucks.  
         [0006]     Prior art treatment systems addressing the need to separate solids from liquids have too often focused on mechanical applications alone. U.S. patent application Ser. No. 10/793,085, incorporated by reference herein, is one example of an adequate mechanical screening system for separation of some particles. However, the resulting output from such exclusively mechanical apparatuses often produces an output that is insufficiently cleaned, particularly when output will be discharged into a municipal sewage system and needs to comply with certain minimum standards for content of biological material and suspended solids in the liquid.  
         [0007]     There is a need in the art for a more comprehensive and thorough liquid/solid waste treatment apparatus and system.  
         [0008]     Further problems arise in the installation, maintenance, and in some circumstances transportability of such an apparatus. There is a need in the art for an apparatus and system whose size, integration and components are readily installed at a wide variety of facilities, and, in other circumstances, easily transportable. There is a further need for adaptability of components. As always, there is a continuing need for economy, durability and efficiency of operation and maintenance.  
       SUMMARY OF THE INVENTION  
       [0009]     An agricultural cleaning apparatus includes a coarse filter assembly, a coarse filter assembly collection tank disposed to receive intermediate slurry from the coarse filter assembly, and a line disposed to receive the intermediate slurry from the coarse filter assembly collection tank. A coagulant addition device in the line adds coagulant to the intermediate slurry upon receipt of the intermediate slurry from the coarse filter assembly collection tanks. A mixer is in the line, downstream of the coagulant addition device. A flocculant addition device in the line adds flocculent to the intermediate slurry downstream of the mixer. A fine filter assembly receives the intermediate slurry from the line and filters it.  
         [0010]     An alternative embodiment has a single filter, the filter is disposed to receive a slurry after coagulant has been added, mixed and then a flocculant has been added.  
         [0011]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0013]      FIG. 1  is a schematic representation of the system of the present invention.  
         [0014]      FIG. 2  is a close-up representation of transfer line  30  including a mixer.  
         [0015]      FIG. 3  is schematic representation of an alternative embodiment. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0017]     Referring now to the drawings where like reference numbers indicate like elements,  FIG. 1  is a schematic representation of the apparatus and system of the present invention. In the depicted embodiment an agricultural truck  6  is being cleaned. Truck  6  is washed with water, as for example a high pressure hose, using known techniques. Waste water is collected in sump  8 . Thereafter the system  10  of the present invention is put into use. From mixed waste sump  8  the waste slurry is pumped with pump  12  through a raw feedline  14  to a first reservoir  18 . In the depicted embodiment, the pump  12  used is a three horsepower pump having a flow rate of up to 160 gallons per minute. The first reservoir is part of a coarse filter assembly  16 .  
         [0018]     First reservoir  18  is disposed to evenly distribute the mixed waste slurry onto a first screen that is a coarse screen  20 . Reservoir  18  has a trap or screen to catch oversized particles such as rocks. The reservoir fills to a preconfigured level and then discharges onto the top of the first coarse screen  20 . Thus, the reservoir  18  serves to properly spread the mixed waste slurry to flow evenly over the screen.  
         [0019]     In the depicted embodiment, the coarse screen  20  is an angled screen over which the mixed waste slurry is poured. Solid waste rolls, tumbles or slides down the slope of the coarse screen  20  and off of the screen. Smaller particles and the liquid portion of the slurry drop through the holes in the screen to be collected in coarse filter tank  22 . In the depicted embodiment the first coarse screen is made of sheet metal with holes fabricated therein that are about 1/16 th  inch in diameter. It is anticipated that in most agricultural applications or applications being used to clean agricultural equipment such as trucks at truck stops, that screens with holes from 1/32 nd  to ⅛ th  inch would be most applicable. However, it is within the scope of the present invention that other diameter perforations or slotted screens may be used. This first processing step produces in the first filter tank  22  intermediate slurry comprised of smaller particulate matter and water. Larger particulate matter has rolled or slid down the coarse screen  20 . At the bottom of the coarse screen  20  a roller system  24  receives these solids and pinches them between rollers to compress them further. Water produced from this application of pressure is returned to the mixed waste sump  8 .  
         [0020]     Overflow from the reservoir  18  is returned to the mixed waste slurry sump via overflow line  28 . Solids dropping through the roller system  24  are collected in receptacle  26  and removed for application elsewhere.  
         [0021]     Coarse filter tank  22  has an exit to intermediate transfer line  30  which receives the intermediate slurry from the coarse filter tank  22 . Material entering transfer line  30  may be pumped with flow rate up to that of pump  12 . Transfer line  30  is described in greater detail below. Proximate to the coarse filter tank  22  and disposed to apply a next process step is a coagulant addition device  32 . In the depicted embodiment, this device is a diaphragm pump. A hopper or tank (not shown in  FIG. 1 ) contains a coagulant, as is more fully described below. In the depicted embodiment, the first coarse diaphragm pump has a flow rate of 4 to 20 gallons per hour. A preconfigured or user adjustable amount of coagulant is added through the diaphragm pump. The amount of coagulant added may be controlled either by adjusting the diaphragm injection rate, and/or by adjusting the overall flow through rate of the intermediate slurry.  
         [0022]     To be effective, the coagulant requires efficient mixing and time. After the addition of coagulant the next process step is mixing. It is within the scope of the present invention that mixing be had with static internal baffles, an active mixer, an open channel or by other means. In the depicted embodiment, as explained in further detail below, mixing is by a series of baffles; that is, a zigzag or serpentine configuration of transfer line  30 .  
         [0023]     The next process step is addition of a flocculant with a flocculant addition device  40 . The flocculant used in the depicted embodiment is described in greater detail below. Like the coagulant, the flocculent is added in the depicted embodiment with a diaphragm pump. The proportions of flocculant used may be preconfigured or user adjustable. This is achieved by adjusting the amount of flocculant inserted in the line  30  through the diaphragm pump and/or adjusting the overall throughput of the line  30  with the pump  32  and/or pump  40 .  
         [0024]     The flocculant is added proximate to the second, fine filter assembly  50 . The second filter assembly is comprised of a second reservoir  52 , a fine screen  54  and discharge  58 . A second filter tank  56  may be included. The intermediate slurry with the coagulant and flocculant added is received at second reservoir  52 . Like first reservoir  18 , the fine filter reservoir  52  is disposed to collect the intermediate slurry and evenly pour it over the fine screen  54  at the top. In the depicted embodiment, the fine screen  54  is a slanted woven screen of  80  mesh. While it is anticipated that screens of 50 to 200 mesh will be most applicable to the fixed installation, agricultural facility, agricultural structure and agricultural machine cleaning installations of some anticipated uses, other meshes remain within the scope of the present invention. Similar to the coarse filter, the fine filter allows water to drop through the screen and the coagulated and flocculated particulate matter to roll or slide across and down the angled screen. Unlike the first filter step, the solid material arriving at the bottom of screen  54  is not processed through any pinch roller or otherwise compressed. From the second filter collecting tank  56 , return line  58  takes the finely filtered water to final sump  60 . Return line  58  may be pumped to final sump  60 . From final sump  60 , the filtered fluid is now ready for return to a municipal sewer service or other uses in an agricultural installation.  
         [0025]      FIG. 2  is a close up of the transfer line  30 , showing the static mixing construction. The transfer line receives intermediate slurry from the coarse filter assembly at the lower left of  FIG. 2  where coagulant is added with a coagulant adding device (diaphragm pump)  32 . Optionally, a flow meter may be installed in the line. Thereafter, in order that the coagulant may have sufficient time to chemically act upon particulate waste matter, the length of transfer line  30  is increased, and correspondingly the flow through time is also increased, by incorporating a zigzag or serpentine configuration  34 . In the depicted embodiment, transfer time from the addition of coagulant to the addition of flocculant is approximately  33  seconds at a flow rate of 90 gallons per minute. The multiple comers in the line  30  created by this serpentine array increase the effective mixing of the coagulant by creating turbulence which promotes mixing of the intermediate slurry with the coagulant. A turn in transfer line  30  is represented on the right hand side of  FIG. 2 , corresponding to the need of the line to raise the intermediate slurry from the bottom of the coarse filter tank  22  to the top of the fine filter assembly reservoir  50 . Further zigzags are installed in transfer line  30  and represented in the side view at  36 . Thereafter, in a post mixing process step, flocculant is added with flocculant adding device  40 . Flocculant adding device  40  may be a diaphragm pump or a positive displacement pump. Thereafter the intermediate slurry is deposited in the fine filter assembly  50  reservoir  52  in the upper left hand corner of the  FIG. 2 .  
         [0026]     In the depicted embodiment, the fine filter assembly includes a screen cleaning device. The disclosure of U.S. patent application Ser. No. 10/793,085 is incorporated by reference as if fully set forth herein. The screen cleaning device includes a moveable pressurized line underneath the screen that incorporates a plurality of nozzles. The nozzles are oriented upwards, towards the screen where they spray pressurized water upwards through the screen in order to keep the perforations and/or screen mesh clear.  
         [0027]      FIG. 3  depicts an alternative embodiment of the present invention. At some applications, a single screen may be adequate. Hence, in the apparatus depicted in  FIG. 3 , sump pump  12  removes waste water to be treated from source  8  and transfers in via line  14  straight into the transfer line  30 . Before the transfer line  30 , the coagulant addition device  32  adds coagulant as it did in the previous described embodiment. Thereafter, all other structure of the apparatus and steps of the method are as described previously, including, generally, the addition of coagulant, a mixing apparatus and step, the addition of flocculant, and screening.  
         [0000]     Coagulants  
         [0028]     A wide variety of coagulants may be advantageously used in combination with the structures of the present invention. These may include organic and non-organic coagulants. They may include straightforward chemical compounds such as aluminum sulfate, iron sulfate or other ferric compositions. They may also include commercially available chemical compounds, such as Magnasol 2765 offered by Ciba.  
         [0029]     As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.