Patent Publication Number: US-11642447-B2

Title: Reverse osmosis water system with heat forward function

Description:
CLAIM OF PRIORITY 
     This application claims priority to and the benefit of U.S. Provisional application with Ser. No. 62/573,447, filed on Oct. 17, 2017, entitled PORTABLE REVERSE OSMOSIS WATER PURIFICATION SYSTEM, which is herein incorporated by reference in its entirety. 
    
    
     CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application relates to U.S. Patent Publication No. 2014/0151297, filed on Nov. 27, 2013, and entitled “Portable Reverse Osmosis Water Purification System,” the disclosure of which is incorporated by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to water purification systems. More specifically, the present disclosure relates to a portable reverse osmosis water purification system. 
     BACKGROUND 
     Reverse osmosis (RO) is a filtration method that removes many types of large molecules and ions from solutions by applying pressure to the solution when it is on one side of a selective membrane. More formally, RO is the process of forcing a solvent from a region of high solute concentration through a semipermeable membrane to a region of low solute concentration by applying a pressure in excess of the osmotic pressure. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other side. The membrane is selective in that large molecules or ions are not allowed through the pores in the membrane, but allows smaller components of the solution (such as the solvent) to pass freely. RO filtration has various applications, including drinking water purification, wastewater purification, food industry uses (e.g., for concentrating food liquid), and health care uses (e.g., dialysis systems). 
     When RO systems are used for providing pure water to a dialysis machine or system issues of component contamination can arise when the pure water source system and the dialysis system have to be disconnected or separated, for instance, when the RO unit is used in a home patient situation where cleanliness is a concern and proper periodic disinfection is critical to patient health or in an RO unit servicing situation when both systems have to be reconnected. At the time of reconnection, the outlet hose or pipe from the pure water source system and the inlet hose or pipe from the dialysis machine may not be totally disinfected and now the operator must manually disinfect the transition point between the two systems with a chemical solution before it is returned to full service. Although the chemical solution and cleaning step may be effective, it is time consuming and the operator needs to flush out the system properly to ensure it is safe to be used on patients. The reconnection becomes an even greater challenge where portable RO machines are being used and such portable units are moved around within a facility or from one facility to the next and the operator needs to ensure that the portable device they intend to use is chemically cleaned (as well as microbial free/bug free) and thoroughly rinsed before patient use. Storage of portable RO units, when not chemically treated for storage, leads to tremendous buildup of active bugs and/or microbial elements. 
     Although all dialysis machines run their own heat disinfection cycle, there is still an area at the water inlet that is not included in this “self-heat disinfection” process. Therefore, it would be very advantageous to provide a chemical-free simple cleaning method of heat disinfecting all three critical areas: the RO unit, the pure water supply path, and the dialysis machine. It would also be highly advantageous to the market to provide a portable or standalone RO system with the capability to disinfect or sanitize any external device (e.g., dialysis machine) or an external port or portion physically disposed or located beyond the pure water source outlet. Further, it would also be advantageous to be able to conduct such a sanitizing or heat disinfecting process without the need for establishing a communications link between the reverse osmosis system and the external device or space being sanitized (forming a closed loop system), as well as without the need for using compatible or like brands (or models) of equipment, thereby allowing all users to be able to take advantage of such a feature. 
     SUMMARY 
     In one example embodiment, In one example embodiment, there is provided a method for sanitizing an external heat tolerant device with heated purified water coupled to an outlet of a heat sanitizable reverse osmosis (RO) system, the RO system having an inlet for receiving potable water from an external potable feed water supply and an internal storage tank for storing purified water, at least one RO membrane unit adapted to receive water from the potable feed water supply and configured to purify the water and deliver the purified water through a delivery conduit to the external heat tolerant device, the method including the step of activating a purified water flow control system configured to supply and regulate the purified water flow and thereafter initiating a variable frequency drive (VFD) pump coupled to the internal storage tank to operate at a first pumping rate until an average feed water supply temperature and a purified water flow rate is determined and then transitioning to a second pumping rate. The method also includes initiating VFD pump stabilization as a flow volume measuring sensor coupled to the purified water flow is triggered upon sensing a water flow below a predefined level and then controlling via controller module the flow of the purified water in the RO system before activating heating of the purified water to be delivered continuously and in a stable state to the external device. In addition, the method includes activating a heat power application system including a heating device for applying heat to the purified water flow initiated by the controller module which is communicatively coupled with the heat power application system, and delivering a heat sanitizing purified water flow with the pump continuously through to the external heat tolerant device. The method further includes regulating a back pressure of the heated purified water via a system control of internal fluid flow directing valves with the controller module such that the controller monitors and controls one or more of a speed of the pump, a water temperature, and a water pressure in a non-closed loop system with the external device during a heat forward process of disinfection of an inlet of the external device. 
     In various related example embodiments disclosed herein of the heat forward process, the flow remains unaffected by feed water disturbances and overall power disturbances once the RO system is restarted. While performing the heat forward process the controller module varies the amount of applied power with a controller to a direct contact inline heating element assembly with an integral thermal sensor disposed within a purified water heating chamber as a function of a sensed purified water temperature. Finally, in ending the heat forward process, a user activates an exit process of the RO system thereby turning off the heating element, emptying the storage tank and cooling water flow paths and returning RO system to an idle mode. 
     In another example embodiment, there is provided a RO and sanitizing system is provided for delivering heated purified water, the RO system having an inlet for receiving potable water from an external potable feed water supply and an internal storage tank for storing purified water, the RO system having at least one RO membrane unit adapted to receive water from the potable feed water supply and configured to purify the water and deliver the purified water through a delivery conduit. The RO system also includes a controller module designed to activate a heat sanitizing cycle within the sanitizing system, the controller module further including a heating power management control circuit configured to isolate the RO system and drive heated sanitized purified water solely through an external heat tolerant device of any brand or manufacturer. Sanitizing water is provided in a continual and stable manner regardless of external flow conditions. The RO system also includes a variable frequency drive (VFD) pump coupled to an RO membrane unit inlet and is communicatively coupled to the controller module, the VFD pump configured to operate at a first pumping rate until an average feed water supply temperature and pressure is determined and then transitioning to a second pumping rate. The VFD pump is further configured to draw water from the storage tank to stabilize the VFD pump from pressure fluctuations in the external feed water supply. The RO system further includes a solenoid valve and manifold assembly that is communicatively coupled to the controller module and to the VFD pump and is configured to control flow of the feed water supply and the purified water. The RO system, in this example embodiment, also includes a low flow velocity sensor communicatively coupled to the controller module and the VFD pump that is configured to initiate VFD pump stabilization. In a related embodiment, the RO system includes an inline heating element with an integral thermal sensor that raises the temperature of the water provided by the VFD pump to a first temperature and also includes a high flow pressure regulating control valve that is communicatively coupled to the controller module that regulates the water pressure from an outlet of the VFD pump flowing into the RO membrane unit. In one example embodiment, the heat forward system does not require a return port or conduit but the feed water temperature should be in a range of about 40° F. to about 100° F. (+/−1° F.) and the target temperature of the heated purified water is above 180° F., preferably 185° F. The minimum flow of feed water should also be about 800 ml to about 1000 ml/minute (but in some cases can be as low as 200 ml/minute). Once the flow target is reached the pump is locked in that pumping rate and the system uses the storage tank as the primary water source. In this example embodiment, the flow remains unaffected by feed water disturbances and overall power disturbances once the RO system is restarted. In a related embodiment, the method includes the step of varying amount of applied power with a controller to a direct contact inline heating element assembly with an integral thermal sensor disposed within a purified water heating chamber as a function of a sensed purified water temperature analyzed and processed by the controller module. In this embodiment, a user activates an exit process of the RO system thereby turning off the heating element, emptying the storage tank and cooling water flow paths and returning RO system to an idle mode. 
     In yet another example embodiment, there is provided a method for sanitizing an external heat tolerant device with heated purified water coupled to an outlet of a heat sanitizable RO system, the RO system having an inlet for receiving potable water from an external potable feed water supply and an internal storage tank for storing purified water, at least one RO membrane unit adapted to receive water from the potable feed water supply and configured to purify the water and deliver the purified water through a delivery conduit to the external heat tolerant device. The method includes the steps of activating a purified water flow control system configured to supply and regulate the purified water flow and of activating a heating power application system including a heating device configured to apply heat to the purified water flow and configured to deliver a heat sanitizing purified water flow continuously to the external heat tolerant device. The method also includes the step of initiating a variable frequency drive (VFD) pump coupled to the internal storage tank to operate at a first pumping rate until an average feed water supply temperature and a purified water flow rate is determined and then transitioning to a second pumping rate. The method further includes the step of initiating VFD pump stabilization as a flow volume measuring sensor coupled to the purified water flow is triggered upon sensing a water flow below a predefined level and providing a regulated flow of purified water by stabilizing the VFD pump from water pressure fluctuations in the external potable water supply by drawing water from the internal storage tank via an isolated storage tank. In a related embodiment, the method includes the step of controlling the flow of the purified water in the RO system before activating the heating of the purified water to be delivered continuously and in a stable state to the external device. 
     In yet another example embodiment, there is provided a method for sanitizing an external heat tolerant device with heated purified water coupled to an outlet of a heat sanitizable RO system, the RO system having an inlet for receiving potable water from an external potable feed water supply and an internal storage tank for storing purified water, and at least one RO membrane unit adapted to receive water from the potable feed water supply and configured to purify the water and deliver the purified water through a delivery conduit. The method includes the steps of activating a heating power application system including a heating device configured to apply heat to the purified water flow and configured to deliver a heat sanitizing purified water flow continuously through to the external heat tolerant device and initiating a variable frequency drive (VFD) pump coupled to the internal storage tank to operate at a first pumping rate until an average feed water supply temperature and a purified water flow rate is determined and then transitioning to a second pumping rate and providing a regulated flow of heated purified water by increasing or decreasing the VFD pumping rate as a function of water temperature fluctuations in the external potable water supply. 
     In any of the disclosed embodiments, the controller is communicatively coupled to a plurality of solenoid control valves and, with the VFD pump, regulates flow and water pressure applied to the RO membrane unit and thus production of heated purified water flow into and out of the external heat tolerant device or its inlet. 
     While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view of an embodiment of a RO water purification system having a heat forward capability for disinfecting an inlet of an external device. 
         FIG.  2    is a schematic view of an example embodiment of a RO water purification system having a heat forward capability for disinfecting an external device as shown. 
         FIG.  3    is a schematic view of the RO system operating to provide a dialysis machine pure water. 
         FIG.  4 A and  4 B  are schematic views of the RO system running a purge operation of a pure water storage tank and refilling the pure water storage tank with pure water, respectively. 
         FIG.  5    is a schematic view of the RO system recirculating heat sanitizing water through components of the RO system. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the Figures,  FIGS.  1  and  2    illustrate schematic views of an embodiment of a RO water purification system having a heat forward capability for disinfecting an external device and the associated fluid flows through the system, respectively. The RO system  100  purifies water provided by a feed water supply  110  for use in various applications, such as dialysis. The RO system  100  possesses monitoring for feed water pressure, feed water quality, feed water temperature, pump outlet pressure, product water pressure, product water temperature, product water quality, and membrane performance (percent rejection), while RO system  200  more specifically discloses the heat forward function and the associated flows with the controlling components in the system. A variable frequency pump  120  provides the pressure required to push water through the RO membrane and against a fixed orifice, while fluid controls along with a controller  160  provide a means of managing flow rates and pressures. In particular, RO system  100  provides for sanitizing with heated purified water, with the RO system having an inlet  112  for receiving potable water from an external (city) potable feed water supply  110  and an internal storage tank  180  for storing purified or potable water (and/or a combination of both depending on the active process), the RO system having at least one RO membrane unit  140  that receives water from potable feed water supply  110  and which purifies the water and delivers the purified water through delivery conduit  142  (and delivers concentrate or waste water through conduit  141  and main manifold  115 ) and eventually provides purified product water at product water outlet  150 . RO system  100  also includes a return outlet  170  for directing excess or unused product water through manifold  115  to storage tank  180  or to a drain outlet  130 . Drain outlet  130  can also receive waste water from membrane  140 . The drain output  130  may be connected to a receptacle or other system for proper disposal of the drain fluid. 
     In this example embodiment, RO system  100  also includes controller module  160  which activates a heat sanitizing cycle within the sanitizing system and that is programmed to operate the components of the system  100  to provide various functionalities (e.g., water purification, sanitization, etc.). Controller module  160  further includes a heating power management control circuit  161  programmed to help isolate part of RO system  100  and drive heated sanitized purified water solely through an external heat tolerant device (heat forward function), such as a dialysis machine or other heat tolerant device or heat tolerant section or portion (device  256  in system  200 ) of an overall system (not shown in system  100 ). A challenge with most prior art RO systems and dialysis machines is found in an external connection section of most dialysis machines when trying to connect the dialysis machine to an RO system—this external connection or portion being called “no man&#39;s land”—as an operator has to remember to separately sanitize or disinfect this area or connection section between the RO system and the dialysis machine. With the various RO systems described herein, this external connection section can be cleaned and disinfected with the heat forward process by using heated purified water that is directed to the non-sterilized connection section, with the right temperature, time and flow, to thoroughly clean and disinfect this external connection section. Such cleaning/disinfection can now be advantageously performed without the need for, as in current RO systems and cleaning accessory combinations, direct/indirect or wired/wireless closed-loop communication between RO system  100  and the dialysis unit (or external heat tolerant device) or the need to introduce a chemical cleaner or process that would need further rinsing after chemical disinfection. 
     Prior art systems require the closed-loop system, between the dialysis machine and the RO sanitizing system in order to overcome stability issues of controlling the water temperature as heating water can quickly turn into a dangerous situation of the temperature escalates to quickly or running indefinitely or exceeding the system&#39;s heat rating or capability (potential for building up too much steam). The heat forward system described herein very closely controls and monitors the heating of the product water through controller  160  and  260  and the various sensors; and flows through the system are monitored closely to look for disturbances and to monitor any pressure potentially building up in the system. An altering or reduction in the heating power application and/or altering a return flow path using one of the solenoid valves and check valves helps to bring RO system and the heat forward process back under control. Any levels that reach maximum current draw for any of the heating elements are managed immediately by controller  160 / 260  so as to limit the current. Further, a control of the pump speed of pump  120 / 220  or control of the flow path also within the purview of the capabilities of controller  160 / 260 . 
     Referring again to  FIGS.  1  and  2   , in this example embodiment of RO system  100 , a series of solenoid valves (SV), check valves (CK) and conductivity sensors (Q) are housed in main manifold  115  to facilitate precise control of heating and cooling flows throughout the RO system and also facilitate the heat forward process, hence a detailed description of these components is provided in connection with  FIG.  1   . Solenoid valve (SV1)  116  is a rinse water solenoid that is a normally closed valve used during the purge, rinse and the heat forward process. It is also open if there is not enough water in the internal water tank during normal dialysis operation. Solenoid valve (SV2)  126  is a waste water valve assembly that includes two solenoids. During normal dialysis operation SV2a is closed and water flows through the orifice hole. The valve is open during flushing, chemical and heat disinfection processes. On the other hand, solenoid valve SV2b opens during the heat forward process to provide a specific amount of backpressure on the membrane. Solenoid valve (SV3)  122 A is a product water solenoid that is normally closed. During startup, the water flow is diverted. Once the product water quality improves below the product water quality alarm, it opens and supplies water to the product line. Solenoid valve (SV4)  128  is a waste recycle control solenoid which is a 3-way valve that directs waste flow to the drain of the RO system. This valve can recycle waste water into the internal tank when the RO system is set up for the water saver function. Solenoid valve (SV5)  172  is a product water return solenoid valve having two solenoids: a) solenoid SV5a provides backpressure during normal operation of the RO system allowing it to supply product water at a pressure of approximately 30 PSI. During heat and chemical modes, this valve is open allowing full flow for proper operation; and b) solenoid SV5b allows product water to the tank or direct to drain. Finally, solenoid valve (SV6)  185  is an inlet water solenoid valve which provides feed water to the internal tank during operation of the RO system during chemical rinse, heat forward and normal dialysis processes. During a heat forward disinfecting process, solenoid valve  126  opens to help configure RO system  100  at a predetermined condition of flow during the heat forward process. 
     Referring again to  FIGS.  1  and  2   , a series of check valves are provided that operate with the various solenoid valves and controller  160  to control the various flows for the heat forward process. A check valve CK1, which is located on the waste side of the membrane, provides backpressure during the heat forward process. A check valve CK2, which is located between the drain line and solenoid valve (SV5)  172 , prevents waste water from entering the product line  150 . A check valve CK3, which is located between the internal tank  180  and drain  130 , will divert water to the tank if the drain line is obstructed. A check valve CK5, which is located in the tank outlet path to the pump  120 , prevents RO feed water  110  from being fed into internal tank  180 . 
     RO system  100  also includes a series of conductivity sensors (Q) which are in communication with controller  160  as well as the solenoid valves and check valves to control flows within system  100 . An RO feed water conductivity sensor (Q1)  118  which monitors the quality and temperature of the inlet water to pump  120 . Inlet water quality and temperature can be viewed from an ANALOG screen on the RO system display/GUI (user interface). The value is compared to the product water quality reading to calculate the percent rejection and is a temperature compensated sensor. A product water conductivity sensor (Q2)  122 C monitors the quality and temperature of the water after it exits the membrane  140 . Product water quality can be viewed from a RUN screen during normal operation and the value is compared to the inlet water quality reading to calculate the percent rejection. Temperature can also be viewed from the ANALOG screen of the RO system  100  display and this sensor is also temperature compensated. An RO feed water pressure sensor (PS1) (near regulator  114 ) monitors the incoming water pressure to the RO system  100  and will shut down the RO system if there is low or high RO feed water pressure. The feed water pressure can be viewed from the ANALOG screen. A pump outlet pressure sensor (PS2)  124  monitors the output of the pump  120  and will shut down the RO system if an over-pressure or under-pressure condition is sensed. The pump outlet pressure can be viewed from the RUN screen of the system display and pump pressure can also be viewed from the ANALOG screen. A product water pressure sensor (PS3-near return  170 ) monitors the product water pressure and will shut down the RO system if an overpressure condition is detected. The product water pressure can be viewed from the RUN screen or from the ANALOG screen. A pressure regulator (PR)  114  controls the incoming feed pressure to the RO system when solenoid valve (SV1)  116  is open. A flow sensor (FS1)  193  switch monitors the flow of product water from the membrane  140 , thereby displaying flow on the RUN screen or the ANALOG screen. A thermocouple (TC/F)  191 , which is located near the heater  190 , monitors the temperature of the water exiting the heater. The temperature is displayed on the RUN screen and can also be viewed from the ANALOG screen. 
     In this example embodiment, RO system  100  also includes a variable frequency drive (VFD) pump  120  that is coupled to an RO membrane unit inlet  139  and that is communicatively coupled to controller module  160 . Pump  120  generally controls the fluid pressure through RO system  100  and generally controls water pressure input to membrane  140 . In some embodiments, pump  120  maybe a pump other than a VFD pump and has a pump pressure of about 160-200 pounds per square inch (psi) (1.10-1.24 MPa). In some embodiments, a pump includes a pressure sensor used to control the operation of VFD pump  120  so as to shut down system  100  if an overpressure condition is detected. In this example embodiment, VFD pump  120  is designed to operate at a first pumping rate until an average feed water supply temperature and pressure (provided by city feed  110 ) is determined and once an appropriate predefined temperature and pressure is achieved then transitioning to a second pumping rate. VFD pump is further designed to draw water from storage tank  180  to stabilize VFD pump  120  from pressure fluctuations in external feed water supply  110 . RO system  100  further includes a solenoid valve and manifold assembly  115  that is communicatively coupled to controller module  160  and to VFD pump  120 , the main manifold being configured to control flow of feed water supply  110  via line  112  and the purified water provided by membrane unit  140  via delivery conduit or outlet  142 . 
     Referring again to  FIG.  1   , during a normal water purification cycle, the solenoid valve  185  (and alternatively valve  116 ) cycles depending on the level of water in the tank  180 . During heating and chemical sanitization modes of operation, described in more detail below, the solenoid valve  116  operates independently to isolate the pump  120 . The quality sensor  122 C and temperature sensor  122 B monitor the quality and temperature of the product water, respectively, after the pure product water exits membrane  140 . The product water quality measured by the quality sensor  122 C can be reviewed (e.g., on a screen associated with the system  100 ) during normal operation. The input of a check valve  144  is connected between the output of the membrane  140  via the valve body  122 A, and an output of check valve  144  is connected to the input of internal tank  180 . Check valve  144  is configured to prevent backflow of water in internal tank  180  into the product water provided to the product water output  150  and simply blocks back flow into the divert valve  122   a . In another part of the system, a solenoid valve  172   a  provides fluid flow resistance during normal operation to the unused product water returning from the external connection  170 . Check valve  174  is configured to prevent backflow of water in internal tank  180  into return water input  170 . In some embodiments, the solenoid valve  172  provides a backpressure to maintain the product water at a pressure of approximately 35 psi (0.241 MPa). Check valve  184  is configured to prevent backflow of water in internal tank  180  from city feed water supply  110 . Check valve  154  is configured to provide a flow path into tank  180  for waste flow if the drain  130  becomes blocked or restricted. Check valve  184  is at an outlet of tank  180  and prevents pressurized potable water from entering tank  180  when valve  116  is open and feeding pump  120  directly. Check valve  174  is connected between drain output  130  and valve  172  and is configured to prevent back flow from drain  130  into valve  172  and or provide a restricted forward flow from valve  172  to drain  130 ; dependent on process conditions. A solenoid valve  185  is controllable to provide potable water flow into tank  180 ; depending on process conditions. 
     In some embodiments, RO membrane  140  is a single membrane comprised of a polymeric material and may include a dense layer in a polymer matrix, such as the skin of an asymmetric membrane or an interfacial polymerized layer within a thin-film-composite membrane, where the separation of the product water from the waste water occurs. Membrane  140  may have a variety of configurations including, for example, spiral wound or hollow fiber configurations. Outputs  141  passes through product water manifold  122  into the larger main manifold  115  and valve  126  at  125  and with the valve  126   a  closed flows through an internal orifice to valve  128 . The flow through  142  enters product water manifold  122  and valve  122   a  and flows to  192  or  144  depending on process and water quality conditions. A check valve  129  prevents backflow from the storage tank and recirculating into valve  126   b.    
     In operation, a purified water flow control system as part of RO system  100  supplies and regulates the purified water flow as well as activates a heating power application system from the heat power module  161 . Heater element  190  applies heat to the purified water flow and through a heat forward process delivers a heat disinfecting purified water flow continuously through to the external heat tolerant device. In operation, variable frequency drive (VFD) pump  120  that is operatively coupled to the internal storage tank is initiated and operates at a first pumping rate until an average feed water supply temperature and a purified water flow rate is determined and then pump  120  transitions to a second pumping rate. VFD pump  120  stabilization is initiated as a flow volume measuring sensor  193  coupled to the purified water flow is triggered upon sensing a water flow below a predefined level and provides a regulated flow of purified water by stabilizing VFD pump  120  from water pressure fluctuations in the external potable water supply  110  by drawing water from the internal storage tank  180  via an isolated storage tank feed. In a related embodiment, this condition occurs when the external potable water pressure falls below a predefined water pressure level. 
     Controller  160  initiates raising the temperature of the regulated purified water flow provided by VFD pump  120  via the internal inline heater element to a predefined level above a fixed minimum temperature of about 80° C. for disinfecting the external heat tolerant device. In a related embodiment, controller  160  varies the amount of applied power to a direct contact inline heating element assembly with an integral thermal sensor disposed within a purified water heating chamber as a function of a sensed purified water temperature. Controller  160  further regulates the purified and heated water flow and pressure into and out of the external heat tolerant device and monitors the water temperature so as to increase or decrease a VFD pump rate to maintain the water temperature at a defined level. Controller  160  also regulates a back pressure of the supplied heated purified water via a system control of internal flow directing check valves and assists in the collection of a redirected flow of heated purified water and unused heated purified water into internal storage tank  180 . 
     Controller  160  provides various operating modes to compensate for a reduction in heated purified water flow in the RO system. Upon sensing a reduction in heated purified water flow below a predetermined level, controller  160  initiates controlling heated purified water flow and temperature within a heating chamber by opening multiple valves on a return side of the heated water flow and increasing the VFD pump rate so as to increase heated water flow velocity. In the instance where the heated purified water temperature fluctuates above or below a defined temperature range, controller  160  initiates adjusting heating power values up or down for a predetermined time and then further monitors a number of water temperature fluctuations above and below the defined temperature range during a defined time period when the number of fluctuations exceeds a defined number during a defined time. Controller  160  also allows the user to manually activate an exit process of the RO system  100  thereby turning off the heating element, emptying the storage tank and cooling water flow paths and returning RO system to an idle mode. 
     In a related embodiment, controller  160  initiates activating a heating power application system of heat power controller  161  including a heating device configured to apply heat to the purified water flow and configured to deliver a heat sanitizing purified water flow continuously through to the external heat tolerant device and initiating a variable frequency drive (VFD) pump coupled to the internal storage tank to operate at a first pumping rate until an average feed water supply temperature and a purified water flow rate is determined and then transitioning to a second pumping rate and providing a regulated flow of heated purified water by increasing or decreasing the VFD pumping rate as a function of water temperature fluctuations in the external potable water supply. Controller  160  controls the flow of the purified water in RO system  100  before activating the heating of the purified water to be delivered continuously and in a stable state to the external device. Upon the heated purified water temperature fluctuating above or below a defined temperature range, heating power values are adjusted up or down for a predetermined time and then further monitoring is initiated of the number of water temperature fluctuations above and below the defined temperature range during a defined time period when the number of fluctuations exceeds a defined number during a defined time. In one example embodiment, controller  160  assists in operating RO system  100  with low inlet pressure from the external feed water supply without shutting down system  100  (as well as system  200  below). 
     Referring now to  FIG.  2   , more specifically there is illustrated a schematic view of an example embodiment of a RO water purification system  200 , illustrating the fluid flows for the heat forward process of system  100 , (having a heat forward capability for disinfecting an external device  256 . In particular, process  200  drives product hot water flow at the product flow outlet  250  via conduit  255  and directs return  270 , via conduit  275 , hot water via main manifold  215  to the storage tank  280  or to the drain output  230 . The drain output  230  may be connected to a receptacle or other system for proper disposal of the drain fluid. In particular, RO system  200  provides for sanitizing with heated purified water the external connection (“no man&#39;s land”) to the external device  256  with water primarily sourced from storage tank  180 . RO system also includes a return outlet  270  and conduit  275  for directing excess or unused product water to storage tank  280  or to a drain outlet  230 . Drain outlet  230  can also receive waste water from membrane  240 . 
     Referring again to  FIG.  2   , in this example embodiment, controller module  260  of RO system  200  not only activates a heat sanitizing cycle within the sanitizing system as well as managing the heat power management control circuit  261  but controller  260  also helps to isolate part of RO system  200  and drive heated sanitized purified water solely through an external heat tolerant device  256 , such as a dialysis machine or other heat tolerant device or heat tolerant section or portion of an overall system, which is coupled to system  200 . Upon the user of RO system  200  selecting the heat forward process via the system GUI (user interface), pump  220  ramps up mainly flowing concentrate through solenoid valve  226 , through check valve  229  and inlet valve  227  and out through drain  230 . Pump  220  further starts moving some volume of pure product water through flow sensor  293  to and out of product outlet  250  and through external device  256  (or the external connection). After flowing through inlet of external device  256 , the product water returns to return  270  and flows through solenoid valve  272  via inlet valve  271   a  and through outlet valve  217   b , and then flows through check valve  274  and out to drain  230  or flows to tank  280 . Once flow is sensed by flow sensor  293 , pump  220  continues to ‘tune’ for a flow rate pre-determined by flow sensor  293  and controller  260  as a function of the temperature measured at quality sensor  218 . Once the target fluid flow rate is stabilized, pump  220  locks its pumping action conditions. Thereafter, with pump  220  in a locked mode, controller  260  initiates the heating of product water flow  250  by a signal to heating power module  261  which in turn signals inline heater  290  and thermocouple  291  to initiate heating and heat monitoring. 
     During all of the heat forward processes (including start-up, running and heat forward cool down), city feed water  210  is always provided via line  212 , and through solenoid valve  285 , and fluid levels usable in the RO system are sensed by water level sensors  281 ,  282 ,  283  of storage tank  280 . Internal tank  280  receives water from check valve  244  and/or the return input  270 . The level of the fluid in internal tank  280  is measured by the level sensors  281 ,  282  and  283  with level sensor  281  being triggered when water in tank  280  is at or above a maximum water level, level sensor  282  being triggered when water in tank  280  is at or below an intermediate water level, and level sensor  283  being triggered when the water in tank  280  is at or below a minimum water level. Outflow from storage tank  280  then occurs through check valve  284  and the inlet of pump  220 . Concentrate flow is discharged to drain  230  via a flow to and through solenoid valve  226  and then through check valve  229  and through valve  227  of solenoid valve  228 . Precise water product flow  250  and thermal stability, under all circumstances, is provided via input signals from sensor  218 , temperature sensor  222 B, pressure sensor  224 , flow sensor  293 , pressure sensor PS 3  at outlet of return  270  and an algorithm uploaded to controller  260 , which precisely controls the operations of solenoid valve  228  (and individual valves  271   a  and  271   b ), inline heater  290  and thermocouple  291 , and pump  220 . 
     In the above embodiments, controller  260  is communicatively coupled to a plurality of solenoid control valves and with VFD pump  220  and as a system regulate flow and water pressure applied to RO membrane unit  240  and thus production of heated purified water flow into and out of the inlet of external heat tolerant device  256  (such as a dialysis machine). The controller is also communicatively coupled to a plurality of solenoid control valves and with the VFD pump so as to regulate flow and water pressure applied to the RO membrane unit and distribution of heated purified water flow throughout the RO system and control and senses fluid outflows out of system  200 . 
     After the external connection or external heat tolerant device is sanitized, a user can initiate a stop of the heat forward process or select “EXIT” procedure, at which time system  200  will automatically proceed to cool itself down via a heat forward cooling cycle in which water flows primarily from, but is not necessarily limited to, city feed  210 . In a related embodiment, water from the storage tank  280  can also be used to cool the system. Water from city feed  210  flows through main manifold  215  and is pumped with pump  220  through membrane  240  through to product outlet  250  (and through heater  290 ) and returns through return port  270  and back through to storage tank  280 . Waste water from membrane  240  also flows back through main manifold  215  and through solenoid valve  226  and check valve  229  and through solenoid valve  228  and out to drain outlet  230 . 
     In a related embodiment, the heat forward system  200  uses storage tank  280  in either break tank mode or it can go directly into a multimode configuration. The heat forward process typically operates at temperatures above 185° F. and can commence as soon as the water temperature is above 185° F. Once the water temperature reaches its target temperature, it locks onto the target and begins flow stability within system  200 . A target temperature of system  200  is dependent on the feed water temperature provided to as system  200  determines as a function of the feed water temperature how much pure water that it can produce, at what volume and at what flow rate. The colder the feed water temperature, the slower and lower the amount of pure water that system  200  will be able to produce in a certain timeframe as cold water takes longer to permeate membrane  140  or  240  than does warmer water. A key advantage is that system  200  can be stable in the heating process due to the low amount of water in the system and due to the stabilization of the flow and stabilization of the pump. In one example embodiment, where the feed water temperature is cold and flow is stable (with the help of solenoid valve (SV5)  272 ), system  200  can estimate generating about 200 ml/minute of flow of product water. Hence, manipulating SV5 and slowing down the operation of pump  120  helps to control any potential pressure build-up in system  200 . If there is a disturbance in the water temperature, controller  260  along with the various temperature sensors and solenoid valves will drive promptly towards system control and stability by monitoring the current fluid flow within system  200 . Further, system  200  shuts down if there is a loss of power as system  200  is configured for manned operation. In one example embodiment, system  200  can reach a target temperature of about 185° F. for heat forward sanitization or for the self-heating process in about 30 minutes depending on the size hose or conduit used in the external connection portion and the temperature of the feed water being used. System  200  will take will take longer to reach a desired pure water generation level depending on the water feed temperature and on the hose length depending on whether the hose used is longer between the dialysis machine and the RO system generating the heat forward water. 
     In this example embodiment, RO system  200  includes a low flow velocity sensor assembly  203  which senses if flow in the line is substantially slowing down, and also protects an inline heater  290 , is communicatively coupled to controller module  260  and VFD pump  220  that is configured to initiate VFD pump stabilization should there be fluctuations in water pressure from city feed  210 . In this example embodiment, RO system  200  also includes an integral thermal sensor  291  that quickly raises the temperature of RO water provided by VFD pump  220  and membrane  240  to a first temperature as a function of a sensed purified water temperature. Unlike previous RO systems that have had the heater element located in the storage tank, moving the heater element out of the storage tank facilitates precise control of the temperature of the purified product water being delivered by RO system  200  and reduces power requirements as only the water that is needed is heated and not the entire storage tank  280  as in other RO systems. In this example embodiment of RO system  200  there is also included a high flow pressure regulator  214  that is communicatively coupled to controller module  260  and which regulates water pressure from city feed  210  and flow sensor  293  that monitors an outlet  221  of VFD pump  220  flowing into RO membrane unit  240 . 
     Further in the above example embodiment, upon sensing an overheating condition in system  200 , controller  260  monitors the water temperature so as to increase or decrease a VFD pump rate to maintain the water temperature at a defined level and upon sensing a reduction in heated purified water flow below a predetermined level, controller  260  proceeds to control the heated purified water flow and temperature by opening multiple valves (primarily solenoid valves) on a return side of the heated water flow and increases the VFD pump rate so as to increase heated water flow velocity thereby eliminating the overheat condition. So as not to have a runaway heating or pressure condition within system  200 , upon the heated purified water temperature fluctuating above or below a defined temperature range and being sensed and acknowledged by controller  260 , controller  260  proceeds to adjust the heating power values up or down for a predetermined time and then further monitors a number of water temperature fluctuations above and below the defined temperature range during a defined time period when the number of fluctuations exceeds a defined number during a defined time. This constant monitoring by controller  260  and associated sensors assists in keeping system  200  stable and in control. 
     One of the main advantages of system  200  and the heat forward method and system taught herein is that fluid outflow from product port  150 / 250  and any other port or orifice of system  200  is controlled and monitored by controller  160 , allowing system  200  to work independently of the dialysis machine (or any other external device) that system  200  is connected to. When solenoid valve (S5)  272  leading to tank  280  but also connected with return  270  at the other end, is open and the fluid flow from external device  256  stops, then controller  260  senses that external device  256  is longer taking water (or the internal solenoid valve is closed and/or their internal tank is full), solenoid valve  272  then adjusts the return path and begins to direct water back through to return port  270  and back to tank  280 . This capability also allows system  200  to control the outflow of heated water by using SV5a to direct water to tank  280  or using SV5 to direct water to drain  230 . In this example, such outflow control if facilitated by the use of a Y-connector to the hose going from product port  250  to external device  256  (one branch) and to return port  270  (second branch). 
       FIG.  3    is a schematic view of RO system  200  operating to provide an external device (e.g., dialysis machine) with pure water. Note from a line code  300  provided on the upper left hand corner describing the various operating conditions of the RO systems described herein. In this example embodiment, product water flows  310  out and there is an intermittent water flow  320  from the return port  270 . There is also a conditional water flow  330 A that flows to storage tank  280  and a water flow  330 B that flows out to drain port  230 . An alternate flow is also provided through solenoid valve SV5 from return  270  out to either tank  280  or out to drain  230 . Waste water can also flow from membrane  240  through SV2 and through its orifice when the solenoid coils are not energized though to solenoid valve (SV4)  128  and then out to either drain  230  or upper path back to tank  280 . Finally, there is a water flow  340  from city feed  210  back to storage tank  280 . 
       FIGS.  4 A and  4 B  are schematic views of the RO system running a purge operation  400  of a pure water storage tank and refilling the pure water storage tank with pure water, respectively. In this example embodiment, storage tank  280  is first emptied then pump  220  is engage via controller  260  to energize solenoid valve SV1 to allow city water  210  to flow through to pump  220 .  FIG.  4 A  the check valve is open for storage tank purge but is closed in  FIG.  4 B  when refilling storage tank. Tank  280  is then refilled and water is pushed around the various conduits of system  200  to continue with purge operation. Once level switch (LSI2)  282  is activated at about half of the tank refill level, controller  260  is signaled to stop pushing water through system  200 . Once purge is complete, chemical cleaning/purge or self-heat cleaning can continue. 
       FIG.  5    is a schematic view of RO system  200  recirculating heat sanitizing water through components of the RO system. In this example embodiment, check valve  229  closes off line  241  from membrane  240 , check valve  244  closes off any back from the outgoing product water line and check valve  274  closes off any backflow from the return line. Storage tank level sensor  282  stays on to measure the storage tank level to ensure there is sufficient water to run the heat circulation process. 
     U.S. Patent Publication No. 2014/0151297 filed on Nov. 27, 2013 is incorporated herein by reference in its entirety. 
     Various embodiments of the invention have been described above for purposes of illustrating the details thereof and to enable one of ordinary skill in the art to make and use the invention. The details and features of the disclosed embodiment[s] are not intended to be limiting, as many variations and modifications will be readily apparent to those of skill in the art. Accordingly, the scope of the present disclosure is intended to be interpreted broadly and to include all variations and modifications coming within the scope and spirit of the appended claims and their legal equivalents.