Abstract:
A water treatment system is provided having an encapsulate manifold with a reverse osmosis cartridge and one or more filter cartridges. The filter cartridge includes a detent for being received within a slot in the manifold head for secure locking engagement. The water treatment system further includes a single probe conductivity monitoring system for monitoring the performance of a reverse osmosis membrane. The water treatment system is also provided in a modular arrangement wherein manifold heads are physically and fluidly coupled together via a clip which interfaces with the modular manifold heads. The water treatment system also allows for a retrofit application to include a permeate pump. The cartridges are also designed to provide a minimum annular inlet gap to minimize spillage during changing of the cartridges.

Description:
[0001]    This application claims priority to U.S. Provisional Patent Application Ser. No. 60/647,680, filed Jan. 27, 2005. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates to water treatment systems and, in particular, to such systems having an encapsulated manifold head and a reverse osmosis cartridge and one or more filter cartridges. 
       BACKGROUND OF THE INVENTION 
       [0003]    Reverse osmosis systems are known. The main part of the system is a semi-permeable membrane through which the untreated water passes. Such systems typically include an additional carbon or ceramic filter which removes contaminates either prior to passing through the membrane or after. Such systems are often installed in residential applications. 
         [0004]    The prior art includes electronic systems which detect when the reverse osmosis membrane requires replacement. Typical prior art systems include measuring the conductivity of the water entering the reverse osmosis cartridge, and then measuring the conductivity of the water at the outlet of the reverse osmosis cartridge. The conductivity of the water is proportional to the total dissolved solids. A ratio of the conductivity levels will provide an indication of the rejection efficiency of the reverse osmosis membrane. 
         [0005]    Prior art systems also include an application wherein a permeate pump is included in a factory installation. The permeate pump provides greater efficiency in the system. The permeate pump increases the net pressure across the reverse osmosis membrane by isolating the membrane pressure from the pressure in the products water and thus reducing the permeate back pressure. 
         [0006]    The prior art also includes systems which address reducing the spillage of fluid occurring during replacement of the cartridges. 
       SUMMARY OF THE INVENTION 
       [0007]    It is an object of the present invention to provide an improved locking mechanism for a filter cartridge and manifold head. 
         [0008]    It is a further object of the present invention to provide an improved method of monitoring the performance of a reverse osmosis membrane in a drinking water supply system. 
         [0009]    It is further object of the present invention to provide a modular manifold head system. 
         [0010]    It is an object of the present invention to provide a system for retrofitting a reverse osmosis filter system to include a permeate pump application. 
         [0011]    It is an object of the present invention to provide a cartridge which has a reduced inlet opening to reduce spillage during changing of the cartridge. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of a water treatment system with a reverse osmosis cartridge and two filter cartridges. 
           [0013]      FIG. 2  is a perspective view of a filter cartridge of  FIG. 1 . 
           [0014]      FIG. 3  is a top view of the filter cartridge of  FIG. 2 . 
           [0015]      FIG. 4  is an exploded view of the filter cartridge of  FIG. 2 . 
           [0016]      FIG. 5  is a bottom perspective view of a manifold head incorporated in the water treatment system of  FIG. 1 . 
           [0017]      FIG. 6  is a block diagram of a reverse osmosis membrane monitoring system. 
           [0018]      FIG. 7  is a process flow chart for the system of  FIG. 6 . 
           [0019]      FIG. 8  is a perspective view of a modular manifold head system. 
           [0020]      FIG. 9  is top perspective view of a modular manifold head. 
           [0021]      FIG. 10  is a schematic diagram of a reverse osmosis water treatment system with a permeate pump. 
           [0022]      FIG. 11  is a cross-sectional view of the modular manifold head and cartridges of  FIG. 1 . 
           [0023]      FIG. 12  is a top perspective view of a modular manifold head in a permeate pump application. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]      FIG. 1  shows one embodiment of a water treatment system in accordance with the present invention. The system includes a manifold head, (see  FIG. 5 ) a first filter cartridge, a reverse osmosis cartridge and a second filter cartridge. A manifold cover is also shown. 
         [0025]      FIG. 2  shows a filter cartridge in accordance with the present invention. The filter cartridge includes a housing having an annular collar with a double lead thread. An inner annular collar is also shown which includes an O ring to provide a seal. A connection fitting is shown extending through the annular collar. 
         [0026]      FIG. 3  shows a top view of the filter cartridge and shows the cylindrical wall of the inner annular collar, as well as the longitudinal extending bead. 
         [0027]      FIG. 4  shows the filter cartridge in an exploded view so as to more clearly show the longitudinal extending bead. It can be seen that the longitudinal extending bead includes a leading end. 
         [0028]      FIG. 5  shows the manifold head having the filter cartridge connection fitting. The filter cartridge connection fitting includes a threaded outer annular collar and an inner annular collar. The inner annular collar having an annular lip and four longitudinal slots. The longitudinal slots are equally spaced apart from one another. 
         [0029]    It will be appreciated that when the filter cartridge is rotated into a fully secured position onto the connection fitting, the filter cartridge comes to rest with the longitudinal extending beads being received by the respective slot. 
         [0030]      FIG. 6  shows a block diagram of a system for monitoring the performance of a reverse osmosis membrane. The system includes a microcontroller having a memory wherein a program resides. The system includes a single probe set which is located downstream of the reverse osmosis membrane. The probe set includes a reference resistor and a thermal resistor. The microcontroller is coupled to a faucet LED for providing an indication to replace the reverse osmosis cartridge. The microcontroller is also coupled to an onboard LED for feedback during operation of an onboard push button also coupled to the microcontroller. A water flow sensor is also coupled to the microcontroller. 
         [0031]      FIG. 7  shows a block diagram which represents the functional steps as executed by the program resident in the memory. 
         [0032]      FIG. 8  is an embodiment of a modular water treatment system. The water treatment system shown in  FIG. 8  includes a modular manifold, a manifold cover, a first filter cartridge, a reverse osmosis cartridge and a second filter cartridge. Also shown is a further modular manifold head and cover, as wells as additional cartridge unit. The system of  FIG. 8  provides a modular system wherein additional modular manifold units may be coupled to the water treatment system via a clip. The clip includes a plurality of arms extending from a planar body portion. Each arm includes a slot and a slanted leading edge. The clip also includes a tubular portion extending through the main body portion. The tubular portion includes a bore extending throughout the tubular portion. 
         [0033]    Each manifold includes an end wall having four openings. 
         [0034]      FIG. 9  shows a perspective view of the manifold including the two ends each having four openings. The openings are arranged in pairs, one above the other. For example, lower opening and upper opening comprise one pair. Each pair of openings includes a pair of upright walls in a spaced apart facing relationship. The upright walls are shown extending from the interior surface of the end wall and the lower surface of the manifold head. A flange extends from the inner surface of the end wall towards the interior compartment of the manifold head. The flange includes an upper ramp and a lower ramp. The flange includes a forward edge and first and second sight edges. The forward edge is generally parallel to the end wall. The first side edge and second side edges form the upper ramp and lower ramp. The upper ramp and lower ramp diverge from one another in a direction away from the inner interior surface towards the interior compartment of the manifold head. One of the four flanges is shown in phantom in  FIG. 9 . The ramps include a proximal end a distal end. The proximal end is located slightly away from the edge of the opening. The distal end is spaced in an interference relationship regarding alignment of the opening.  FIG. 9A  shows additional detail. 
         [0035]    With reference to  FIG. 8 , it will be appreciated that as the clip is inserted into the openings of the manifold head to the right of the figure, the slanted edge of each of the resilient arms will be deflected by the respective ramp. Once the clip if fully inserted through the four openings, the slot will extend past the distal end and the two arm pairs will clamp about the respective distal end with the edge of the slot coming into locking engagement with the distal end of the ramp. Meanwhile, the tubular portion will be received by the tube fitting connector for sealing engagement. The other modular manifold head will be coupled in similar manner. 
         [0036]      FIG. 10  shows a graphical representation of a water treatment system wherein an automatic shut-off valve cover may be removed and replaced with another cover adapted to accommodate a permeate pump application. With reference to  FIG. 11 , a cross-section of a water treatment system is shown including the modular manifold head, first cartridge, reverse osmosis cartridge and second filter cartridge. The manifold head is shown to include a connection fitting for receiving the respective connection fitting of the reverse osmosis cartridge. The manifold head includes a first manifold access port for coupling to an output of a reverse osmosis cartridge, a second manifold access port coupled to an output of a reverse osmosis stage. A non-permeate pump cover is adapted to seal the first and second access ports for a non-permeate pump application. A permeate pump cover is adapted to also seal the first and second access ports and includes a permeate pump output port which receives a tube fitting connector. The permeate pump cover includes a first access and a second access port and a flow channel in communication with the first and second access ports, as well as the permeate pump output port. A check valve assembly is located in the first access port for coupling the output of the reverse osmosis cartridge. The second cover includes a substantially planer body portion which defines a first end and a second end. Mounting holes are provided for fastening the cover to the manifold head. 
         [0037]    The manifold includes a lower diaphragm receptacle portion having an opened upper portion. The second cover includes an upper diaphragm receptacle portion for mating with the opened upper portion to form a diaphragm cavity which receives a diaphragm. The upper diaphragm receptacle portion includes an opening and fluid communication with the fluid channel. The manifold head includes a flow channel coupled to an output port of a pre-filter stage and an input port of the reverse osmosis stage, wherein the flow channel is in fluid communication with the lower diaphragm receptacle portion of the manifold head. It will appreciated that the water treatment system may be assembled at the factory with a non-permeate pump cover, wherein the plug is provided at the permeate pump output port. A retrofit kit may be provided wherein the first cover is removed and replaced with the second cover having the tube fitting connector. A quarter inch tubing may then be coupled to the tube fitting connector and extend through a routing hole as shown in  FIG. 12 . The tubing extends downward and to a permeate pump as shown in  FIG. 10 . The permeate pump has a permeate outport having a tubing which runs to a T-connector. The T-connector has a further tubing coupled to a storage tank, as well a tubing coupled back to the manifold head. The brine side of the permeate pump includes a brine end from the drain flow of the manifold head and a brine out tubing which couples to the drain point. For sake of completeness, the tubing is also shown coming from the supply inlet and tubing is shown going to the faucet. 
         [0038]    The installation kit includes at a minimum the second cover and further may include a replacement check valve, as well replacement O rings, tubing, fasteners and installation instructions. 
         [0039]      FIG. 11  also shows the filter cartridge having a reduced gap at the connection fitting in order to minimize spillage during changing of the filter cartridge. The novel features of the filter cartridge are explained below. However, it will be apparent that the features can be incorporated into the reverse osmosis cartridge as well. 
         [0040]    The filter cartridge includes external cartridge housing having a cylindrical portion with a top portion and a bottom portion. The bottom portion has a closed end. The top portion includes a shoulder having a generally cylindrical neck portion extending upward from the shoulder. The cylindrical neck portion defines a portion of a connection fitting. The cylindrical neck portion defines a cylindrical bore having a cylindrical bore wall which defines a first diameter. The cylindrical bore wall includes an annular ring protruding from the wall and defining a second diameter which is smaller than the first diameter. An internal cartridge housing includes a top portion with a shoulder, a tube portion extending upward from the internal shoulder, and the tube portion defining an outlet bore. The tube portion defines an outer diameter having a third diameter, wherein the third diameter is smaller than the first and second diameter. The tube portion and the annular ring define a cartridge inlet having an annular gap. It will be appreciated that the annular gap is minimized by this design and thereby reduces the likelihood of spillage. The manifold head is adapted to conform with the filter cartridge. In particular, the manifold head includes a connection fitting which includes an internal annular collar having a length defined such that when the cartridge is assembled to the manifold, the internal annular collar extends around the tube portion and up to the annular ring, with a minimum spacing for tolerance.