Abstract:
The current application is to multi-canister water-filtration systems with two or more canister-type water filters as well as pressure-monitoring components to allow for the pressure drop across at least one of the canister-type water filters to be monitored and filtration-efficiency degradation detected.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Provisional Application No. 61/637,006, filed Apr. 23, 2012. 
     
    
     TECHNICAL FIELD 
       [0002]    The current application is directed to water-filtration systems and, in particular, to a multi-canister water-filtration system that includes multiple canister-type water filters and filter-monitoring devices. 
       BACKGROUND 
       [0003]    Canister-type water filters have been available for many years for initial treatment of public-utility-supplied water and treatment of private-well water supplied to residential and commercial buildings. While cost effective and generally robust, canister-type water-filtration systems currently include only a single type of filter media and therefore exhibit relatively low efficiencies for removing certain classes of water contaminants while having relatively greater efficiencies for removing other classes of water contaminants. Furthermore, canister-type water filtration systems may exhibit significant pressure losses and various types of degradation over time, both of which are difficult to monitor for and detect. Building owners and residents continue to seek broader-spectrum and higher-capacity water-filtration systems which exhibit less and more easily detected filtration-efficiency degradation. 
       SUMMARY 
       [0004]    The current application is to multi-canister water-filtration systems with two or more canister-type water filters as well as pressure-monitoring components to allow for the pressure drop across at least one of the canister-type water filters to be monitored and filtration-efficiency degradation detected. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  shows an external view of a dual-canister multi-filter water-filtration system that represents one example of the water-filtration systems to which the current application is directed. 
           [0006]      FIG. 2  shows the dual-canister multi-filter water-filtration system from the rear. 
           [0007]      FIG. 3  shows a view of the dual-canister multi-filter water-filtration system from below. 
           [0008]      FIG. 4  is an exploded view of the dual-canister multi-filter water-filtration system discussed above with reference to  FIGS. 10-3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]      FIG. 1  shows an external view of a dual-canister multi-filter water-filtration system that represents one example of the multi-canister water-filtration systems to which the current application is directed. The dual-canister multi-filter water-filtration system receives input, untreated water in a source-water tube  102  and outputs filtered water to an output pipe  104 . The filtration system includes two canister-type water filters  106  and  108  mounted below a shelf-like metal housing  110  with two pressure indicators  112  and  114 . Pressure-relief buttons for the two canister-type filters are exposed through the housing  116  and  118 . 
         [0010]      FIG. 2  shows the dual-canister multi-filter water-filtration system from the rear. In this illustration, the two canisters  106  and  108  are clearly visible, including the lower canister housings  202  and upper head units  204  for the canister-type water filters. A first tap  206  into the source-water pipe provides a source-water pipe pressure input  208  to the first pressure gauge ( 112  in  FIG. 1 ) and a second pressure tap  210  in the output filter-water pipe provides a pressure input  212  to the second pressure gauge ( 114  in  FIG. 1 ). 
         [0011]      FIG. 3  shows a view of the dual-canister multi-filter water-filtration system from below. In this illustration, the second pressure gauge ( 114  in  FIG. 1 ) and the first pressure gauge ( 112  in  FIG. 1 ) are clearly visible, as are the taps  212  and  206  into the filtered-water pipe and source-water pipe, respectively. Note that the source-water pipe  102  branches into two source-water branches  302  and  304  input to the two canister-type filters and each canister-type filter separately outputs filtered water to output-branch pipes  306  and  308  that are later combined to form a single output pipe  104 , as shown in  FIG. 1 . 
         [0012]      FIG. 4  is an exploded view of the dual-canister multi-filter water-filtration system discussed above with reference to  FIGS. 1-3 . For sake of conciseness, those elements already discussed and labeled with numeric labels in the previous figures are provided similar labels in  FIG. 4 . Note that the canister-type water filters each include multiple O-rings  401 - 404  and internal filter canisters  406  and  408 . Additional fittings and fasteners are shown in  FIG. 4 . 
         [0013]    By dividing the input water-source pipe into two branches, the input water is filtered, in parallel, by two canister-type water filters, decreasing by half the flow of water through each canister with respect to a single canister-type water filter effectively doubling the water-filter volume across which pressure is dropped. As a result, the lifetime of the water filters is extended and potential for significant pressure loss through the water-filtration system significantly decreased. The pressure gauges allow for this pressure drop across the first canister-type water filter to be monitored, so that critical contaminant loading and other conditions that may affect water-filtration efficiency can be prevented. Canister-type water filters are provided a stable, robust mounting platform that allows the canister housings to be unscrewed from the filter head units without removing the filter head units from the dual-canister multi-filter system. 
         [0014]    Although the present invention has been described in terms of particular embodiments, it is not intended that the invention be limited to these embodiments. Modifications within the spirit of the invention will be apparent to those skilled in the art. For example, multi-canister water-filtration systems may employ more than two canister-type water filters and more than a single pair of pressure gauges. Additional types of filter-monitors devices may be included in alternative examples of the multi-canister water-filtration system. The multi-canister water-filtration systems to which the current application is directed may have various different dimensions and use various different types of fasteners and fittings to securely mount the canister-type filters within the multi-canister water-filtration-system assembly to provide separate input and output pipe branches to each canister-type water filter. 
         [0015]    It is appreciated that the previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.