US 20050000867 A1
A drinking water filter assembly has a filter cartridge which includes a filter element contained in a pressure vessel for unitary disposal, the cartridge received on a base containing attachment fittings for ease in installation and replacement with limited exposure to contaminants during a filter change. A flow powered flow meter is provided which measures the quantity of flow through the filter for alerting the user to replace the filter cartridge.
15. A device for monitoring a flow of water to a water filter comprising a water filter counter having a rotatable impeller in fluid communication with a water supply delivered to a water filter, the impeller having means for generating an electrical output in proportion to water flow by the impeller, and counter means to receive the electrical output and to total the quantity of water flowing to the filter.
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This application claims priority in U.S. Provisional patent application No. 60/329,278, filed Oct. 13, 2001.
This invention relates to a water filtering apparatus particularly suited for use in the home. The water filtering apparatus may be counter top or under sink mounted.
The quality of drinking water is of concern to those obtaining water from public water systems as well as those obtaining water from private wells. There can be a wide variation in the amount and type of contaminants contained in drinking water, such as those occurring with seasonal runoff, or those present as by-products from water chlorination. To assure individual water quality, local filters may be used for removing contaminants from drinking water, mounted on or under a counter top, or on a faucet. These have gained in popularity.
In U.S. Pat. No. 6,001,249, a water filter system having multiple filters is shown. In U.S. Pat. No. 6,024,867, a counter top water filtering system is shown. In U.S. Pat. No. 5,622,618, a water filter with a flow metering system is described. However, the success of these and other filters for drinking water has been limited primarily because they require periodic user attention to change the filter at the appropriate time. Several of the filters are complex in design, making it difficult for the user to change a filter. Typically, the filter element is a disposable stand alone unit which is placed in a permanent housing which acts as a pressure vessel during the filtration process. Consequently when changing the filter element, the user must remove the housing to expose the filter element and the user is then exposed to a wet, contaminated filter, removal possibly causing some contaminants to dislodge and enter the drinking water after the new filter element is installed.
If not changed at the correct interval, due to inconvenience or otherwise, filtration efficiency could deteriorate to the point where the contaminants begin to pass through into the drinking water.
Consequently, there is a need for a relatively simple water filtering apparatus having the capability for quick and easy change of the filter element, without exposing the user to contaminants or release of the contaminants from the filter element. There is also a need for means to monitor filter usage and to alert a user to timely change the filter element.
It is object of the present invention to provide a water filtering apparatus that has a simple design.
It is a further object of the present invention to provide a water filtering apparatus with a limited number of parts.
It is a further object of the present invention to provide a water filtering apparatus with a contained filter element to avoid leakage and exposure of the user to contaminants.
It is yet another object of the present invention to provide a water filtering apparatus that has monitoring means to alert the user that the life of the filter is expiring.
These and other objects of the present invention are achieved by a water filtering apparatus comprising:
Using a self-contained filter element avoids the user having to contact a contaminated filter element as the contained filter element and container are disposed of as a unit. The container itself is a pressure vessel, but one of low cost and simple construction, so as to minimize replacement cost. A non-water receiving cover may be used for aesthetic purposes to cover the assembly.
To change a filter element, the self-contained filter element or cartridge is released from the base and a new cartridge mounted in its place. Because it is a simple unit, this can be done without exposing the user to the filtered contaminants, or even wetting their hands.
The filter cartridge 3 has a container 19 surrounding a filter element 20. The container totally encloses the filter element except for a pair of openings, 21 and 22, best seen in
There are numerous types of filter elements that can be contained such as those designed to remove particulate matter, such as microporous filters, or those designed to remove organic compounds, such as carbon filters. Others may include filter elements incorporating reverse osmosis membranes, ion exchange media, resins, polymers, diatomous earth, etc. Generally, a microporous carbon or ceramic filter with at least one membrane to capture particles and micro-organisms could be used because of its adaptability. However, a carbon filter alone would likely be sufficient in most applications.
The filter element may be sized to be received in the container with a slight interference fit to provide a degree of compression for maintaining the position of the filter element and sealing at the ends such that all water entering the container can only exit after passing through the filter element. However, over compression should be avoided to prevent damage to the filter element or buckling which could produce a leakage path allowing unfiltered water to by-pass the filter element. The threaded container assembly may have an advantage as the degree of compression can be somewhat controlled as the container halves are tightened together.
As described previously, the filter cartridge has two openings, one for unfiltered water to enter and one for filtered water to exit. As shown in
The water filter assembly 1 has the advantage that it can be used on a counter top or under a sink. During installation or replacement, the user never contacts the filter element as this is encased in the container. An advantage of the inventive water filter assembly is that the connections between the filter cartridge and base are small and thus more easily sealed. (See
It may be preferred to use a filter element of carbon block with paper wrapping and having plastic molded ends, for low cost contaminant removal. Also, the threaded passage 29 can be provided by using a metal insert which is press fit into the bottom housing 24, which may be made of plastic.
Quick connect couplings 10 and 11 are preferably used to connect the supply tubing 12 and discharge tubing 13 to the base to ease assembly, as again, the object is to provide a water filter apparatus that is simple in design, construction, installation and operation.
The output tube 13 is pressed into the quick connect fitting on one end and is pressed on or clamped to a fitting on the other end leading to the spigot 14. The input tube is pressed into the quick connect fitting 10 at the filter and is attached to the water supply at the other end by clamping, threading, etc., depending on the supply piping and available or installed fittings. The two quick connects thus mate to the element support 2 a in the base which receives the housing.
The base 40 has a pair of threaded coupling points, 49 and 50 for engaging a supply tube and a return tube, not shown. The assembly can thus be somewhat remotely located for convenient servicing.
A particular problem with water filters is the need to timely change the filter element. The life of a filter is dependant on the quantity of fluid flow through the filter and level of contaminants. However, fluid flow is difficult to monitor in a cost effective manner, and most systems rely on periodic filter replacement, for example on a semi-annual or quarterly basis of course, water usage can vary significantly from day to day, and periodic replacement risks disposing of a filter which still has adequate filtration capacity, or continuing to use a filter which has passed its ability to provide good filtration. However, no simple reliable system for assuring timely changing of a filter element has been available.
The impeller has a stationary magnet 65 that is in proximity to a pair of wire coils 63 and 64, forming a generator such that as the impeller spins electricity is generated. The electricity powers an electronic counter 66, with the power flow from the generator being proportional to water flow, to provide a simple self contained self powered counter which can be preset such that when a given throughput volume is reached, the user is alerted to replace the filter cartridge. The alert can be given using visual, audio or another type of signal. Thus, the life of the filter is tracked by the quantity of fluid delivered to the filter, and the optimum utilization of the filter element is achieved.
One advantage of the inventive water filter assembly is that two small o-rings seal the fluid passages concentrically to the housing. In addition, the threads engaging the housing to the element support are also relatively small (perhaps ⅝″ diameter verses 5-6″ dia. with the prior art reusable housing). Thus, there is a mechanical advantage in sealing the housing to the threaded surfaces. As the housing only needs to last the life of the filter (up to about 1 year), the cost of producing a structurally sound housing is reduced. Further, the customer does not have contact with the actual filter element during a filter change, as any contaminants would be contained within the disposable housing.
No tools are required to change the filter, and the change does not result in significant fluid leakage. The user's mechanical advantage is maximized by the difference of the filter assembly's diameter to the sealing o-ring's diameters.
The attachment is preferably obtained using fine pitch metal threads that also increases the user's mechanical advantage. The inlet connection hose can exit the water filter system in any direction because of the swiveled right angle quick disconnect that is used to attach it. The pressure vessel may be hidden with the optional decorative cover. The under counter model preferably consists of a structure that uses compression of the filter assembly to hold it rigidly in position and allow the same filter assembly to be used in an application where greater pressures exist. This allows a more cost effective design for the replacement filter cartridge assembly.
Using the present invention, a simple filtration solution is obtained which enables a user to install a filter system easily, enable filter changes with limited exposure to the contaminated filter element, and without concern for releasing residue in a housing as occurs when only the filter element is removed from the filter assembly.
While preferred embodiments of the invention have been shown and described it will be understood that various changes or modifications can be made without varying from the scope of the invention.