Abstract:
A system and method of reducing odors of livestock confinement operations which utilizes a V-shaped filter of wood chips disposed in front of exhaust fans from manure pits under a livestock confinement building and a method of cleaning the wood chips involving spraying them with a solution.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/529,233 filed on Dec. 15, 2003 by Roger H. Treloar of Solon, Iowa and Robert R. Treloar of Fountain Hills, Ariz., entitled PORC P7 (pork odor reducing control). 

   BACKGROUND OF INVENTION 
   Over the past 10 years, water and air quality issues relating to the swine industry have been a public concern in the United States. Fairly or not, strong opposition by the general public and many environmental groups to new swine facility construction or renovation has prompted the United States Environmental Protection Agency (EPA) to enact, through state agencies such as the Department of Natural Resources (DNR), stringent, and increasingly limiting, construction, disposal, and emission standards. These new guidelines have merit in what they are trying to achieve—cleaner air and water, with better construction practices to ensure a minimal risk of contamination to the environment. However, the overall effect of these new regulations has been to cause some states to put a moratorium on any new swine facility construction, and further has caused many growers to rethink their expansion plans. Industry leaders estimate the value of pork production in Iowa alone is $12 billion. Significant declines in pork production would represent a considerable loss to the economy in terms of activities involved directly or indirectly with pork production. The new DNR regulations may guide the direction of the future of the swine industry, but they do not address existing sites where urban sprawl and real estate concerns for property owners near facilities have caused disharmony between producers and urban residents. 
   Currently, there are many technologies dealing with odor control. Some deal with application methods, such as manure injection below ground. A few address the issue of open pits versus covered pits. Others deal with composting of mortalities and the installation of windbreaks. 
   While these prior art technologies have enjoyed some success and have been used or at least experimented with in the past, they do have some drawbacks. 
   First of all, the direct injection of manure below ground is an efficient way to control runoff and potential water contamination but falls short in the odor this process creates during the 24- to 48-hour soil saturation period during application. 
   Secondly, composting is a good way to deal with disposal of mortalities, but it is a small percentage of the odor produced by a swine facility. 
   Thirdly, windbreaks of growing trees are either very expensive or have very long lead times until they become optimal in their performance and may alter the airflow dynamics of the site. As a result, effective and efficient ventilation may be compromised. 
   Fourthly, pit additives are costly and vary greatly in their performance. Some additives may alter the water chemistry and change the composition of the manure. Changing this composition would affect the elements of the manure management plan. 
   Experimentation with the natural bio-filtering may cause clogging and sealing of the filtering medium. The apparatus demands a great deal of site preparation and ground work and is labor intensive during maintenance and replacement of the filtering medium. 
   Adaptation of industrial scrubbers to address the odor issue requires the addition of input energy and water into the system. The addition of water may dilute the manure in the pit if returned to the pit. This would change the composition of the manure and affect the fertilizer value of the manure. Efforts to recycle the water from the scrubber are currently complex and costly. 
   Consequently, there exists a need for improved methods and systems for reducing the undesirable effluent from swine production facilities. 
   SUMMARY OF INVENTION 
   It is an object of the present invention to provide a system and method for reducing odorous emissions from swine production facilities in an efficient manner. 
   It is a feature of the present invention to utilize a filtering system disposed at exhaust fans in swine production facilities. 
   It is an advantage of the present invention to remove much of the undesirable odorous emissions before they are permitted to become dispersed. 
   It is another advantage of the present invention to reduce noise output from swine production facilities which employ exhaust fans. 
   It is yet another advantage of the present invention to reduce the level of animal dander exhausted from the facilities; it is believed that this may reduce the distance that odor can travel from the facility. 
   It is another feature of the present invention to provide for alternate exhaust escape routes in the event that the filter may be clogged. 
   It is another advantage of the present invention to not expose the swine to danger as a result of improper operation of the odor emission control system. 
   It is another feature of the present invention to utilize inexpensive components for the filter. 
   It is yet another advantage of the present invention to provide a relatively low cost approach to achieving significant reductions in odorous emissions. 
   It is yet another feature of the invention to utilize a filter system which has no moving parts and utilizes no electricity. 
   It is another advantage of the invention to provide a highly reliable odorous emission control system. 
   It is another advantage of the present invention to utilize a filtering medium that may be reused and recycled in an environmentally friendly way. 
   The present invention is an apparatus and method for reducing undesirable emissions from swine production facilities, which has been designed to satisfy the aforementioned needs, provide the previously stated objects, include the above-listed features, and achieve the already articulated advantages. The present invention is carried out in a “wasted resource-less” manner in a sense that the cost of the present invention is low, the time consumed in repairing, maintaining and/or replacing the present invention is low, and the energy consumption used by the present invention is low. 
   Accordingly, the present invention is a system and method comprising a partial filter being placed in front of an exhaust fan on a swine production facility. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The invention may be more fully understood by reading the following description of the preferred embodiments of the invention, in conjunction with the appended drawings wherein: 
       FIG. 1  is a perspective view of a side of a swine production facility with several filters of the present invention. 
       FIG. 2  is a perspective view of one of the filters of  FIG. 1 . 
       FIG. 3  is a partially dismantled upper perspective view of the filter of  FIG. 2  with a top portion having been removed to expose a backside of the filter. 
       FIG. 4  is an upper perspective view of the filter of  FIG. 3  with the top portion in place. 
       FIG. 5  is a view of the material retaining structures of the present invention in an unassembled state. 
   

   DETAILED DESCRIPTION 
   Now referring to the drawings wherein like numerals refer to like matter throughout, and more specifically referring to  FIG. 1 , there is shown a swine production facility of the present invention generally designated  100 , including a confinement building having an exterior wall  102  and numerous exhaust ports  104 . The facility  100  may be a typical confinement building with a concrete waste pit disposed underneath it for collecting and treating animal waste (primarily feces, urine and undigested animal feed). The exhaust ports  104  are typically exhaust fans blowing the vapors associated with the waste pit out of the pit so as to maintain livable conditions within the building. The exhaust port  104  may have a large fan, which could have an output of between 1500 cubic feet per minute (CFM) and 4000 CFM. 
   The filter system  110  is shown having a filter system top section  112 , which is preferably in two pieces, but tops having a single or more than two pieces may be preferred in certain applications. Filter system top section  112  has a filter system top section edge flow restricting barrier  113 , which may be a board, plastic or other panel which tends to force the air exiting through the filter system top section  112  to flow upward through the media therein and not diagonally through the edges. Filter system  110  is shown in a triangular shape and has two filter system side sections  114  (only one side is shown in  FIG. 1 ). Filter system side section  114  includes a filter system side section frame  116 , which is preferably made of polyvinylchloride (PVC) pipe or other material with properties suitable to exposure to the outdoor elements and to the emissions which exhaust from the pit. Filter system top section or panel  112  and filter system side section or panel  114  also comprise a hardware cloth, wire mesh, non-metallic mesh or chicken wire. Preferably this mesh is coated with a plastic material, such as PVC or a suitable substitute to reduce corrosion. 
   In an exemplary embodiment of the present invention, the filter system side section  114  is approximately 30 in. high and 54 in. long with a thickness of 5 in. The top filter panels  112  consist of two identical right triangles with 38-inch sides and 4-inch thickness constructed in the same manner. Top filters rest on a top section support structure  402  ( FIG. 4 ), which is preferably 15×15×30 inches. Filter system top section edge flow restricting barrier  113  may be treated wood panels attached to the top filter panels to also contain the filtering medium, while a front panel  122  is fastened to contain the filtering medium at the seam or “V” of the side panels  114 . The filter system base edge  118  is a 3-inch diameter base frame of PVC which surrounds the filter system  110  to allow for a collection area when the filter medium  119  is being changed. By using PVC and PVC-coated hardware cloth, the optimum standards may be achieved while maintaining cost effectiveness and durability. By using the absorption capabilities of wood mulch/chips as the filtering medium  119 , a reusable, environmentally friendly product of the filtration process is created which is easily disposed or recycled. The wood chips are medium sized with an average size being 1″ to 2″, and it is believed that western bark may be preferred, but it should be understood that quality and consistency of the wood or bark may vary efficiency. 
   It should be understood that the foregoing description is preferred when the exhaust port  104  has a flow rate of between 1500 CFM and 4000 CFM and an exit opening of between 18″ and 24″. In general, the higher the flow rate, the larger the required surface area of the internal sides of the filter system  110 . 
   Now referring to  FIG. 2 , there is shown a larger view of the filter system  110  of  FIG. 1 , with a better view of filter system top section  112  and both filter system side sections  114 . It should be understood that a V-shaped configuration with a top section is preferred; however, other shapes and configurations which cause a large portion of the exhaust air from exhaust port  104  to pass through the medium  119 , could be used as well. 
   Now referring to  FIG. 3 , there is shown a partially dismantled view of the filter system  110  of  FIGS. 1 and 2 . The filter system top section  112  has been removed to expose to view the inside of filter system  110 . Exhaust fan outlet end  302  is shown, as well as alternate exhaust air escape opening  304 . Alternate exhaust air escape opening  304  is an important gap or opening. Without an alternate exhaust air escape opening  304 , or with an inadequately sized alternate exhaust air escape opening  304 , a deadly backup of the system could occur if the filter system  110  were to become clogged or have a dramatically reduced ability to pass exhaust through. The area of alternate exhaust air escape opening  304  would need to be larger as the flow rate of the exhaust port  104  increases. For example, swine facilities with larger and fewer exhaust fans would require large filter systems  110  with larger alternate exhaust air escape openings  304  than would facilities with more fans each outputting a lower volume of air per minute. With an exhaust fan operating at 3000 CFM, it is believed that the separation of filter system side section  114  from exterior wall  102  would be about 18 inches. 
   Also, medium (bark) is shown disposed at the apex of the V between the panel  122  and the front edges of filter system side sections  114 . 
   Now referring to  FIG. 4 , there is shown a filter system  110  of  FIG. 3 , with the filter system top sections  112  disposed on a top section support structure  402 . 
   Now referring to  FIG. 5 , there is shown the components of the filter system  110 , in an unassembled state, without the medium. 
   Throughout this description, reference is made to swine production, because it is believed that the beneficial aspects of the present invention would be most readily apparent when used in connection with swine; however, it should be understood that the present invention is not intended to be limited to swine, and should be hereby construed to include other stock confinement and manure treatment applications as well. For example only, and not intended as a limitation, the filter system  110  could be used with turkey, chicken, or cattle confinement operations. Also, the filter system  110  could be used with any type of manure or animal waste storage or treatment facility irrespective if it is located under an animal confinement building. 
   In operation, the filter system  110  of the present invention could be operated as follows: 
   1.Filter system  110  is deployed in front of an exhaust port  104  of a containment structure for manure and/or animal waste. 
   2.Air from inside the containment structure exits through the exhaust port  104  and encounters the filter system  110 . 
   3.A solution such as ASBA 5 and BP5 is applied to the medium in the filter system  110 , which tends to enhance the performance of the medium in filtering out undesired emissions. 
   The solution may be variable, depending upon the particular type of emission which is targeted for removal. For example, if ammonia is the primary targeted emission for filtering, then a preferred solution may be: 
   The ASBA5 available from PORC Systems, LLC of Solon, Iowa, which is made up of water, sulfuric acid not greater than 5%, dilute acetic acid not greater than 5%, pine oil not greater than 1.5%, emulsifier not greater than 1.5%. 
   If Hydrosulfide is the primary target, then a preferred solution may be: 
   The BP5, also available from PORC Systems, LLC of Solon, Iowa, is made up of water, sodium bicarbonate not greater than 5%, pine oil not greater than 1.5%, emulsifier not greater than 1.5%. The emulsifier may be common house-hold dishwashing liquid. 
   The solution may be applied with a hand sprayer to the exterior and interior surface of the filter system  110 . It is believed that a 1 to 2-week interval may be sufficient; of course, in some situations, more frequent applications may be desirable. 
   It is thought that the method and apparatus of the present invention will be understood from the foregoing description and that it will be apparent that various changes may be made in the form, construct steps, and arrangement of the parts and steps thereof, without departing from the spirit and scope of the invention or sacrificing all of their material advantages. The form herein described is merely a preferred exemplary embodiment thereof.