Patent Publication Number: US-2005126477-A1

Title: Color code identification of powder filters

Description:
RELATED APPLICATION  
      This application claims the benefit of pending U.S. provisional patent application Ser. No. 60/529,125 filed on Dec. 12, 2003 for COLOR CODE IDENTIFICATION OF POWDER FILTERS, the entire disclosure of which is fully incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      Powder filter cartridges are common in powder application systems. The filters are typically used as part of a powder overspray recovery system. Such systems commonly use a large air flow or containment air to draw powder overspray into the recovery system. The filters are used to separate the powder from the containment air. The powder may be returned to the supply or otherwise dispositioned. Once laden with powder it is often difficult for an operator to know what type of filter is needed for replacement, and it can also be difficult to identify filters from the original manufacturer. Other types of filters are used in recovery systems, such as after filters.  
     SUMMARY OF THE INVENTION  
      The invention contemplates ways to identify filters so as to make their replacement much easier and less time consuming. In accordance with one aspect of the invention, a filter is provided with a visually perceptible indicia or coding that readily identifies one or more characteristics of the filter, without interfering with the operation of the filter. In one embodiment, the visually perceptible indicia is realized in the form of a color code.  
      In accordance with another aspect of the invention, a visual indicator is provided with a filter to convey information to an operator with the information relating to one or more characteristics of the filter, wherein the indicator need not be removed from the filter during its use. In one embodiment, a color band or other color coding is provided with the filter.  
      These and other aspects and advantages of the present invention will be understood and apparent from the following detailed description of the exemplary embodiments in view of the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective illustration partially exploded of a powder recovery system using one or more filters in accordance with the invention; and  
       FIG. 2  is an isometric of a filter in accordance with an exemplary embodiment of the invention. 
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS  
      With reference to  FIG. 1 , a typical powder spray system  10  is partially shown and includes a powder containment spray booth  12  having a plurality of walls  14 , a ceiling  15  and a floor  17 . Although there are many different types of powder overspray recovery systems, in the example of  FIG. 1  there is a recovery system  16  in the form of a bank of filters  18  that are exposed to the interior volume of the booth  12 . The number of filters  18  used in a particular system (six are illustrated in  FIG. 1  hereof, namely  18   a - 18   f ) will depend on the amount of powder overspray generated among other factors. A blower or other air mover (not visible in the drawings) is used to pull air from the spray booth through the filters  18 . Powder laden air passes into the filters and the powder is separated from the air. Secondary or after filters  20  are typically provided to further separate powder from the air before the air is exhausted to atmosphere. Air is drawn through the filters  18  through opening  19  that communicate with the after filters and blower. Operation of such a recovery system is well known and taught, for example, in U.S. Pat. No. 6,514,305 issued to Stephens, et al., the entire disclosure of which is fully incorporated herein by reference. The application system  10  also would include one or more spray guns (not shown).  
      Various aspects of the invention are described herein and are illustrated as embodied in various combinations in the exemplary embodiments. These various aspects however may be realized in alternative embodiments either alone or in various other combinations thereof. Some of these alternative embodiments may be described herein but such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments. Those skilled in the art may readily adopt one or more of the aspects of the invention into additional embodiments within the scope of the present invention even if such embodiments are not expressly disclosed herein. Additionally, even though some features and aspects and combinations thereof may be described herein as having a preferred form, function, arrangement or method, such description is not intended to suggest that such preferred description is required or necessary unless so expressly stated. Those skilled in the art will readily appreciate additional and alternative form, function, arrangement or methods that are either known or later developed as substitute or alternatives for the embodiments described herein.  
      As would be appreciated from  FIG. 1 , when the filters  18  are installed in the recovery system  16  they are only partially visible and once they are laden with powder their characteristics may be difficult to discern. Therefore, it may be difficult for an operator to know the size, mounting arrangement, media and other filter specific information that is needed in order to replace one or more of the filters once they are no longer useable.  
       FIG. 2  illustrates an exemplary embodiment of the invention as incorporated into one or more of the filters  18 . In this example, the filter unit  50  includes a filter media portion  52  that is porous to air but that separates out a large portion of the powder. The filter media will separate powder particles that are larger than the porous openings in the media, as is known. It is therefore important for a replacement filter to have the correct media characteristics, dimensions, size and mounting arrangement. Prior to the present invention, the dirty filter would have to be partially or fully removed and visually inspected in order to ascertain some of these characteristics. The filter shown in  FIG. 2  is a pleated filter media such as with pleats  52   a  although other media configurations may be used.  
      Typical filters also include end caps  54  that are used to position and stabilize the filter within the recovery system. The end caps may optionally have gaskets  56  to provide air tight seals to prevent powder from entering the after filter or blower arrangements.  
      In accordance with the invention, the filter  50  is provided with a color code  58  that can be used to visually convey to an operator the information needed about the filter in order to select an appropriate replacement or original installation. In this example the color code is realized in the form of a color band  60  that is placed about the periphery or outer surface of the media. The band can be made of an appropriate size that it is easily viewable yet does not interfere with the function of the media. There can be many different embodiments of a band, including a band that is only partially about the filter and that is located other than in the middle of the filter structure. The color code concept can be realized in many other different ways. For example but not by way of limitation, a color stripe may be applied to the media external surface or the media itself colored. Multiple colors may be used to convey additional information, or specific color patterns may be used. Moreover, especially for use when new, the gaskets or end caps may include coloration.  
      The information conveyed by the color code can be any number of characteristics of the filter, including but not limited to: size or other dimensions, mounting arrangement, media porosity, media material, pleat count and so on. The color code concept can improve efficiency not only of identifying filter characteristics of spent filters but also can make new filter installation and inventory control more accurate.  
      The invention also contemplates a powder application system that incorporates a filter having a color code. The invention also contemplates a method for making a filter that includes the step of incorporating a color code with the filter to convey visually information about the filter.  
      Although the exemplary embodiment illustrates the invention in use with cartridge filters that typically are readily viewable by an operator, the invention may also find application with other filters, such as for example the after filters  20 . These filters typically can be viewed upon moving one or more access panels, but the filters may also be color coded to provide information to the operator as in the case with the cartridge filters. In most cases they can be viewed without removing access panels.  
      The invention has been described with reference to the preferred embodiment. Modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.