Patent Abstract:
An airnet constructed of a filtering fabric sewn in the shape of a windsock is connected to the discharge end of a fan. Actuation of the fan causes ambient air to flow through the fan and into the airnet. The air passes through the filtering fabric of the airnet and particulate matter in the ambient air is trapped and retained within the airnet. The airnet and fan combined form a portable air filtration system capable of filtering the ambient air in confined spaces, such as bathrooms being finished or remodeled, in a relatively quick and efficient manner.

Full Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the field of air filtration, and more particularly to an air filtration system and method that provides a portable and effective structure for filtering particulate matter from ambient air. 
     BACKGROUND 
     Construction of the type including finishing and remodeling of interior rooms of commercial and residential buildings typically involves procedures that cause particulate matter to be raised into the ambient air. Such particulate pollution may be even more prevalent during demolition projects. 
     For example, when finishing of a room requires the installation of drywall, also known as gypsum board, plasterboard, rock lath, and sheetrock, the drywall must be appropriately processed. Such processing usually includes cutting of the drywall to fit specified dimensions and to provide openings for fixtures, such as electrical switches and outlets, as well as overhead lights and ceiling fans. 
     Cutting of the drywall in this manner causes dust particulates to rise up into the ambient air. Since this occurs in a typically closed environment, workers are exposed to inhalation of these dust particles. Appropriate precautions, such as the use of breathing masks, must then be taken in order to limit the exposure of workers to such dust particulates. 
     Another construction procedure that causes dust particulates to enter the ambient air is the cutting of concrete blocks, concrete tile board, bricks, ceramic tiles, or plaster and/or fiberglass materials. Again, during the construction or finishing of rooms, such materials must be appropriately cut to size and to provide suitable access to fixtures. 
     In all of these processes, the dust particles tend to hang in the ambient air in a confined space, such as a bathroom, thus exposing the workers therein to breathing in such particles. As mentioned above, breathing masks may be used in order to limit such exposure, however, such masks are uncomfortable and inconvenient to wear. 
     Further, eye protection is also necessary in order to protect the worker&#39;s eyes from exposure to such dust particles. 
     Accordingly, the following disclosure discusses embodiments of a portable air filtration system that can quickly and efficiently remove particulate matter from the ambient air in confined spaces. 
     SUMMARY 
     The portable air filtration system discussed herein is composed of an airnet filtering bag. The airnet filtering bag is formed of an air permeable filtering fabric processed into the general shape of a windsock having one open end and one closed end. The open end of the airnet filtering bag is defined by a perimeter. 
     A closing element, such as an elastic band, or bungee cord, is retained within a chamber formed around substantially the entire perimeter of the open end. As an alternative, a pull cord having two free ends extending through respective openings in the chamber may be provided as a closing element. 
     The open end of the airnet is arranged to be attached to the discharge end of a fan and the closing element is configured to close the open end around a perimeter of the fan in order to retain the airnet in position thereon. This may be accomplished via the elasticity of the closing element, or in the case of the pull cord, by tying the free ends in a knot. 
     The chamber in which the closing element is retained may be formed by folding over and sewing a flap of the fabric at the open end onto itself. The elastic closing element can be sewn into the chamber and can extend around the perimeter of the open end. 
     In an exemplary embodiment, the filtering fabric has an air permeability of about 55 cfm. 
     The above described airnet filtering bag can be utilized in a system that includes a fan having a discharge end. The fan has a perimeter, which may be circular, rectangular, or square, or any other suitable shape. The open end of the airnet filtering bag is placed around the perimeter of the fan at the discharge end and is secured in place by the closing element. 
     The above described system may be used to filter ambient air by providing the above described airnet filtering bag, providing a fan having a discharge end, engaging the open end of the airnet filtering bag to the perimeter of the fan at the discharge end of the fan, closing the closing element around the perimeter of the fan to retain the airnet in position thereon, and actuating the fan in order to filter ambient air through the airnet. 
     Thus, a convenient and efficient portable air filtering system is provided to eliminate dust and other particulate matter from the ambient air in a substantially enclosed space is provided. Of course, the use of the disclosed air filtering system is not limited to construction or demolition sites, but may be utilized in any area where it is desired to remove particulate matter from the ambient air. 
     The numerous other advantages, features and functions of embodiments of an air filtration system will become readily apparent and better understood in view of the following description and accompanying drawings. The following description is not intended to limit the scope of the air filtration system, but instead merely provides exemplary embodiments for ease of understanding. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
         FIG. 1  is an exploded view of the airnet, closing element, and fan of a first embodiment of an air filtration system; 
         FIG. 2  is an exploded view of the airnet, closing element, and fan of a another embodiment of an air filtration system; 
         FIG. 3  is a partial cross-sectional view of the closing element within the chamber according to the embodiment of the air filtration system of  FIG. 1 ; 
         FIG. 4  is a perspective view of the air filtration system of  FIG. 1  in an unactuated state; and 
         FIG. 5  is a perspective view of the air filtration system of  FIG. 4  in an actuated state. 
     
    
    
     It should be noted that the drawing figures are not necessarily drawn to scale, but instead are drawn to provide a better understanding of the components thereof, and are not intended to be limiting in scope, but rather to provide exemplary illustrations. It should further be noted that the figures illustrate exemplary embodiments of an air filtration system and the components thereof, and in no way limit the structures or configurations of an air filtration system and components thereof according to the present disclosure. 
     DETAILED DESCRIPTION 
     In an exemplary embodiment, as seen in  FIG. 1 , an air filtration system includes an airnet filtering bag  10  having a perimeter  12  that defines an open end  14  of the airnet. Opposed to the open end  14  is a closed end  16 . Thus, the airnet  10  has a generally windsock shaped configuration. 
     The airnet  10  is formed from a filtering fabric. The fabric may be formed from any suitable natural or synthetic materials, including, but not limited to, polyester and/or nylon and/or cotton continuous filament and/or spun yarns. For example, the fabric may be a woven natural polyester having a weave on the order of 55 cfm. The fabric may be in sheet form and folded into the generally windsock shape. The shape of the airnet  10  may be formed by sewing the filtering fabric. Alternatively, adhesives or ultrasonic welding may be utilized to create the seams necessary to provide the generally windsock shape. 
     The filtering fabric is an air permeable fabric that allows air to pass through the fabric, but which does not allow particulate matter, such as drywall, concrete, plaster, ceramic, and/or fiberglass particles, to pass therethrough. In an exemplary configuration, the filtering fabric has an air permeability of about 55 cfm. In other words, the filtering fabric will allow an air volume of about 55 cubic feet per minute to pass therethrough. 
     The airnet  10  is used in combination with the discharge end of any suitable fan  30  in order to filter particulate matter from the ambient air. In this exemplary embodiment, the fan  30  has a housing  32  that is defined by a circular perimeter  34 . 
     As will be understood by a skilled artisan, the fan  30  has two sides. When the fan  30  is actuated ambient air will pass from the supply side, through the fan housing  32  and out of the discharge side of the fan  30 . 
     The open end  14  of the airnet  10  is engaged with the perimeter  34  of the fan  30  around the discharge side of the fan  30  so that when the fan  30  is actuated, the ambient air will flow out of the discharge end of the fan  30  and into the airnet filtering bag  10 . Thus, any particulate matter that is contained in the ambient air will be trapped within the airnet filtering bag  10 , while the air permeability of airnet filtering bag  10  will allow the ambient air to flow therethrough, thus filtering the ambient air of particulate matter. 
     In order to maintain the airnet filtering bag  10  in place on the discharge end of the fan  30 , a closing element  20  is provided around the perimeter  12  of the open end  14  of the airnet filtering bag  10 . 
     As shown in detail in  FIG. 3 , the closing element  20  is positioned within a chamber  18  that is formed around the perimeter  12  of the open end  14  of the airnet filtering bag  10 . The chamber  18  may be formed by folding a flap of fabric at the open end  14  over and onto itself and creating a seam by sewing, adhesion, ultrasonic welding, or any other suitable method. 
     The closing element  20  may be inserted into the space defining the chamber  18  prior to the step of sewing, so as to be sewn into the chamber  18 . 
     The closing element  20  may be in the form of an elastic band or bungee cord, or any other suitable material that will provide a secure closure mechanism, as discussed below. 
     As shown in  FIGS. 4 and 5 , the air net  10  is secured to the perimeter  12  of the fan  30  at the discharge end of the fan  30 . A suitable frame or stand  40  may be provided to elevate the fan  30  and the airnet  10  from the ground or supporting surface so that when the fan is actuated, the airnet  10  can expand under the increase in pressure provided by the airflow from the supply side to the discharge side of the fan  30 . 
     The closing element  20  is sized such that, in an unstretched state, it is slightly smaller than the perimeter  34  of the fan  30 . Thus, when the open end  14  of the air net  10  is engaged around the perimeter  34  of the fan  30 , the closing element  20  will expand. In this manner, a frictional engagement between the perimeter  12  of the open end  14  of the airnet  10  and the perimeter  34  of the fan  30  is accomplished. Thus, the airnet  10  is retained in position on the fan  30  such that all of the ambient air passing from the discharge end of the fan  30  must past through the airnet filtering bag  10 . 
     Thus, the airnet filtering bag  10  serves to accumulate the particulate matter that was suspended in the ambient air that passed through the fan. 
     In this exemplary embodiment, the ambient air in a substantially closed space, such as a bathroom, having a size of 5 feet by 8 feet will circulate through the airnet  10  in about 50 seconds, thus clearing the entire room of substantially all of the airborne pollutants, such as particles of concrete dust. Therefore, after the air filtering system is used in such a room for 50 seconds, it is not necessary for workers to wear masks or goggles. 
     After the room has been cleared of airborne particles, the fan can be turned off, and the airnet  10  removed therefrom. The airnet  10  then acts as a container for the filtered particles. The particles within the airnet  10  can be removed simply and easily to another suitable container, such as a garbage bin or dumpster. The airnet  10  may be simply turned inside out and shaken to remove all of the particulate matter. 
     Thus, in the exemplary embodiment shown in FIGS.  1  and  3 - 5 , the air filtration system is set up and used in the following manner. The airnet  10  and the fan  30  are provided. The open end  14  of the airnet  10  is engaged around the perimeter  34  of the discharge end of the fan  30 . The closing element  30  and the open end  14  are then closed such the airnet is retained in position on the fan  30 . The assembly is positioned directly in the area where the ambient air is meant to be filtered, and the fan  30  is actuated in order to draw the ambient air therethrough, as illustrated at A in  FIG. 4 , and into the airnet  10 . The fan  30  is left running for as long as desired in order to filter the ambient air through the airnet  10 . The fan  30  is then turned off, and the airnet  10  may be removed from the fan  30 . 
     It is noted that the fan speed may be varied depending upon the particulate sizes or weights to be filtered. For example, for lighter particulates, the fan may be set at a lower speed to provide slower blade movement in order to avoid a backpressure that may hinder the accumulation of the particulates. For larger or heavier particulates, a higher fan speed that provides a quicker blade movement may be used. 
     As previously mentioned, the airnet filtering bag may be connected to any suitable fan. Accordingly, in an alternative embodiment, a rectangular or square shaped box fan is utilized. 
     As shown in  FIG. 2 , the air filtration system has a similar construction to the previously discussed embodiment. An airnet filtering bag  50  having a perimeter  52  defining an open end  54  and further having an opposed closed end  56  is shown. The airnet filtering bag  50  may be constructed in the same manner as discussed above. 
     A rectangular or square box fan  70  having a box housing  72  that defines a rectangular or square perimeter  74  is shown. The open end  54  of the airnet  50  maybe engaged with the discharge end of the fan  70  in the manner discussed above in order to achieve the functions discussed above, with the exception of an alternative closing element  60 . 
     As shown in  FIG. 2 , the closing element  60  is a draw or pull string that is substantially inelastic, and which has two free ends. The closing element  60  can be retained in a chamber around substantially the entire perimeter  52  of the open end  54  of the airnet  50  in the same manner as discussed above. 
     The chamber includes first and second openings  58  defined therethrough to allow the first and second free ends of the drawstring closing element  60  to extend out of the chamber. 
     The airnet filtering bag  50  can be engaged to the discharge end of the fan  70 , and the free ends of the closing element  60  can be tied in a knot  62  (shown in phantom in  FIG. 2 ) so as to create a frictional engagement between the perimeter  52  of the airnet and the perimeter  74  of the fan  70 . 
     In all remaining respects, the air filtering system of this embodiment functions as described above with respect to the embodiment of FIGS.  1  and  3 - 5 . 
     While particular embodiments of a portable air filtering system are discussed above utilizing specific components, the components of the system described herein may be formed in any suitable manner recognized by a skilled artisan. 
     It is understood that the size of the airnet and the components thereof can be adjusted in order to accommodate numerous different fan sizes and numerous different airflow settings. 
     Of course, it is to be understood that not necessarily all objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. 
     The skilled artisan will recognize the interchangeability of various disclosed features. In addition to the variations described herein, other known equivalents for each feature can be mixed and matched by one of ordinary skill in this art to construct an air filtration system in accordance with principles of the present invention. 
     Although this invention has been disclosed in the context of certain exemplary embodiments and examples, it therefore will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above.

Technology Classification (CPC): 1