Patent Description:
This application relates to <CIT>, filed on Nov. <NUM>, <NUM>, and entitled "Portable Reverse Osmosis Water Purification System,".

The present disclosure relates to water purification systems. More specifically, the present disclosure relates to a portable reverse osmosis water purification system.

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. <CIT> describes a heat sanitization system for a reverse osmosis unit that utilizes the pure water produced by the reverse osmosis unit to sanitize parts of the reverse osmosis unit.

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.

The invention is as claimed in the claims. In one example, 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 RO membrane unit inlet 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 examples 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, a RO 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 <NUM> kelvin (<NUM>°F) to about <NUM> kelvin (<NUM>°F) plus or minus <NUM> kelvin (+/- <NUM>°F) and the target temperature of the heated purified water is above <NUM> kelvin (<NUM>°F), preferably <NUM> kelvin (<NUM>°F). The minimum flow of feed water should also be about <NUM> to about <NUM>/minute (but in some cases can be as low as <NUM>/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, 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 RO membrane unit inlet 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, 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 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, and alternatives falling within the scope of the invention as defined by the appended claims.

Referring now to the Figures, <FIG> and <FIG> 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 <NUM> purifies water provided by a feed water supply <NUM> for use in various applications, such as dialysis. The RO system <NUM> 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 <NUM> more specifically discloses the heat forward function and the associated flows with the controlling components in the system. A variable frequency pump <NUM> provides the pressure required to push water through the RO membrane and against a fixed orifice, while fluid controls along with a controller <NUM> provide a means of managing flow rates and pressures. In particular, RO system <NUM> provides for sanitizing with heated purified water, with the RO system having an inlet <NUM> for receiving potable water from an external (city) potable feed water supply <NUM> and an internal storage tank <NUM> 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 <NUM> that receives water from potable feed water supply <NUM> and which purifies the water and delivers the purified water through delivery conduit <NUM> (and delivers concentrate or waste water through conduit <NUM> and main manifold <NUM>) and eventually provides purified product water at product water outlet <NUM>. RO system <NUM> also includes a return outlet <NUM> for directing excess or unused product water through manifold <NUM> to storage tank <NUM> or to a drain outlet <NUM>. Drain outlet <NUM> can also receive waste water from membrane <NUM>. The drain output <NUM> may be connected to a receptacle or other system for proper disposal of the drain fluid.

In this example embodiment, RO system <NUM> also includes controller module <NUM> which activates a heat sanitizing cycle within the sanitizing system and that is programmed to operate the components of the system <NUM> to provide various functionalities (e.g., water purification, sanitization, etc.). Controller module <NUM> further includes a heating power management control circuit <NUM> programmed to help isolate part of RO system <NUM> 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 <NUM> in system <NUM>) of an overall system (not shown in system <NUM>). 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'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 <NUM> 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'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 <NUM> and <NUM> 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 <NUM>/<NUM> so as to limit the current. Further, a control of the pump speed of pump <NUM>/<NUM> or control of the flow path also within the purview of the capabilities of controller <NUM>/<NUM>.

Referring again to <FIG> and <FIG>, in this example embodiment of RO system <NUM>, a series of solenoid valves (SV), check valves (CK) and conductivity sensors (Q) are housed in main manifold <NUM> 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>. Solenoid valve (SV1) <NUM> 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) <NUM> 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) 122A 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) <NUM> is a waste recycle control solenoid which is a <NUM>-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) <NUM> 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 <NUM> 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) <NUM> 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 <NUM> opens to help configure RO system <NUM> at a predetermined condition of flow during the heat forward process.

Referring again to <FIG> and <FIG>, a series of check valves are provided that operate with the various solenoid valves and controller <NUM> 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) <NUM>, prevents waste water from entering the product line <NUM>. A check valve CK3, which is located between the internal tank <NUM> and drain <NUM>, 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 <NUM>, prevents RO feed water <NUM> from being fed into internal tank <NUM>.

RO system <NUM> also includes a series of conductivity sensors (Q) which are in communication with controller <NUM> as well as the solenoid valves and check valves to control flows within system <NUM>. An RO feed water conductivity sensor (Q1) <NUM> which monitors the quality and temperature of the inlet water to pump <NUM>. 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) 122C monitors the quality and temperature of the water after it exits the membrane <NUM>. 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 <NUM> display and this sensor is also temperature compensated. An RO feed water pressure sensor (PS1) (near regulator <NUM>) monitors the incoming water pressure to the RO system <NUM> 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) <NUM> monitors the output of the pump <NUM> and will shut down the RO system if an overpressure 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 <NUM>) 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) <NUM> controls the incoming feed pressure to the RO system when solenoid valve (SV1) <NUM> is open. A flow sensor (FS1) <NUM> switch monitors the flow of product water from the membrane <NUM>, thereby displaying flow on the RUN screen or the ANALOG screen. A thermocouple (TC/F) <NUM>, which is located near the heater <NUM>, 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 <NUM> also includes a variable frequency drive (VFD) pump <NUM> that is coupled to an RO membrane unit inlet <NUM> and that is communicatively coupled to controller module <NUM>. Pump <NUM> generally controls the fluid pressure through RO system <NUM> and generally controls water pressure input to membrane <NUM>. In some embodiments, pump <NUM> maybe a pump other than a VFD pump and has a pump pressure of about <NUM>-<NUM> pounds per square inch (psi) (<NUM>-<NUM> MPa). In some embodiments, a pump includes a pressure sensor used to control the operation of VFD pump <NUM> so as to shut down system <NUM> if an overpressure condition is detected. In this example embodiment, VFD pump <NUM> is designed to operate at a first pumping rate until an average feed water supply temperature and pressure (provided by city feed <NUM>) 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 <NUM> to stabilize VFD pump <NUM> from pressure fluctuations in external feed water supply <NUM>. RO system <NUM> further includes a solenoid valve and manifold assembly <NUM> that is communicatively coupled to controller module <NUM> and to VFD pump <NUM>, the main manifold being configured to control flow of feed water supply <NUM> via line <NUM> and the purified water provided by membrane unit <NUM> via delivery conduit or outlet <NUM>.

Referring again to <FIG>, during a normal water purification cycle, the solenoid valve <NUM> (and alternatively valve <NUM>) cycles depending on the level of water in the tank <NUM>. During heating and chemical sanitization modes of operation, described in more detail below, the solenoid valve <NUM> operates independently to isolate the pump <NUM>. The quality sensor 122C and temperature sensor 122B monitor the quality and temperature of the product water, respectively, after the pure product water exits membrane <NUM>. The product water quality measured by the quality sensor 122C can be reviewed (e.g., on a screen associated with the system <NUM>) during normal operation. The input of a check valve <NUM> is connected between the output of the membrane <NUM> via the valve body 122A, and an output of check valve <NUM> is connected to the input of internal tank <NUM>. Check valve <NUM> is configured to prevent backflow of water in internal tank <NUM> into the product water provided to the product water output <NUM> and simply blocks back flow into the divert valve 122a. In another part of the system, a solenoid valve 172a provides fluid flow resistance during normal operation to the unused product water returning from the external connection <NUM>. Check valve <NUM> is configured to prevent backflow of water in internal tank <NUM> into return water input <NUM>. In some embodiments, the solenoid valve <NUM> provides a backpressure to maintain the product water at a pressure of approximately <NUM> psi (<NUM> MPa). Check valve <NUM> is configured to prevent backflow of water in internal tank <NUM> from city feed water supply <NUM>. Check valve <NUM> is configured to provide a flow path into tank <NUM> for waste flow if the drain <NUM> becomes blocked or restricted. Check valve <NUM> is at an outlet of tank <NUM> and prevents pressurized potable water from entering tank <NUM> when valve <NUM> is open and feeding pump <NUM> directly. Check valve <NUM> is connected between drain output <NUM> and valve <NUM> and is configured to prevent back flow from drain <NUM> into valve <NUM> and or provide a restricted forward flow from valve <NUM> to drain <NUM>; dependent on process conditions. A solenoid valve <NUM> is controllable to provide potable water flow into tank <NUM>; depending on process conditions.

In some embodiments, RO membrane <NUM> 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 <NUM> may have a variety of configurations including, for example, spiral wound or hollow fiber configurations. Outputs <NUM> passes through product water manifold <NUM> into the larger main manifold <NUM> and valve <NUM> at <NUM> and with the valve 126a closed flows through an internal orifice to valve <NUM>. The flow through <NUM> enters product water manifold <NUM> and valve 122a and flows to <NUM> or <NUM> depending on process and water quality conditions. A check valve <NUM> prevents backflow from the storage tank and recirculating into valve 126b.

In operation, a purified water flow control system as part of RO system <NUM> supplies and regulates the purified water flow as well as activates a heating power application system from the heat power module <NUM>. Heater element <NUM> 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 <NUM> 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 <NUM> transitions to a second pumping rate. VFD pump <NUM> stabilization is initiated as a flow volume measuring sensor <NUM> 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 <NUM> from water pressure fluctuations in the external potable water supply <NUM> by drawing water from the internal storage tank <NUM> 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 <NUM> initiates raising the temperature of the regulated purified water flow provided by VFD pump <NUM> via the internal inline heater element to a predefined level above a fixed minimum temperature of about <NUM> for disinfecting the external heat tolerant device. In a related embodiment, controller <NUM> 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 <NUM> 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 <NUM> 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 <NUM>.

Controller <NUM> 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 <NUM> 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 <NUM> 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 <NUM> also allows the user to manually activate an exit process of the RO system <NUM> 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 <NUM> initiates activating a heating power application system of heat power controller <NUM> 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 <NUM> controls the flow of the purified water in RO system <NUM> 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 <NUM> assists in operating RO system <NUM> with low inlet pressure from the external feed water supply without shutting down system <NUM> (as well as system <NUM> below).

Referring now to <FIG>, more specifically there is illustrated a schematic view of an example embodiment of a RO water purification system <NUM>, illustrating the fluid flows for the heat forward process of system <NUM>, (having a heat forward capability for disinfecting an external device <NUM>. In particular, process <NUM> drives product hot water flow at the product flow outlet <NUM> via conduit <NUM> and directs return <NUM>, via conduit <NUM>, hot water via main manifold <NUM> to the storage tank <NUM> or to the drain output <NUM>. The drain output <NUM> may be connected to a receptacle or other system for proper disposal of the drain fluid. In particular, RO system <NUM> provides for sanitizing with heated purified water the external connection ("no man's land") to the external device <NUM> with water primarily sourced from storage tank <NUM>. RO system also includes a return outlet <NUM> and conduit <NUM> for directing excess or unused product water to storage tank <NUM> or to a drain outlet <NUM>. Drain outlet <NUM> can also receive waste water from membrane <NUM>.

Referring again to <FIG>, in this example embodiment, controller module <NUM> of RO system <NUM> not only activates a heat sanitizing cycle within the sanitizing system as well as managing the heat power management control circuit <NUM> but controller <NUM> also helps to isolate part of RO system <NUM> and drive heated sanitized purified water solely through an external heat tolerant device <NUM>, 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 <NUM>. Upon the user of RO system <NUM> selecting the heat forward process via the system GUI (user interface), pump <NUM> ramps up mainly flowing concentrate through solenoid valve <NUM>, through check valve <NUM> and inlet valve <NUM> and out through drain <NUM>. Pump <NUM> further starts moving some volume of pure product water through flow sensor <NUM> to and out of product outlet <NUM> and through external device <NUM> (or the external connection). After flowing through inlet of external device <NUM>, the product water returns to return <NUM> and flows through solenoid valve <NUM> via inlet valve 271a and through outlet valve 217b, and then flows through check valve <NUM> and out to drain <NUM> or flows to tank <NUM>. Once flow is sensed by flow sensor <NUM>, pump <NUM> continues to 'tune' for a flow rate pre-determined by flow sensor <NUM> and controller <NUM> as a function of the temperature measured at quality sensor <NUM>. Once the target fluid flow rate is stabilized, pump <NUM> locks its pumping action conditions. Thereafter, with pump <NUM> in a locked mode, controller <NUM> initiates the heating of product water flow <NUM> by a signal to heating power module <NUM> which in turn signals inline heater <NUM> and thermocouple <NUM> 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 <NUM> is always provided via line <NUM>, and through solenoid valve <NUM>, and fluid levels usable in the RO system are sensed by water level sensors <NUM>, <NUM>, <NUM> of storage tank <NUM>. Internal tank <NUM> receives water from check valve <NUM> and/or the return input <NUM>. The level of the fluid in internal tank <NUM> is measured by the level sensors <NUM>, <NUM> and <NUM> with level sensor <NUM> being triggered when water in tank <NUM> is at or above a maximum water level, level sensor <NUM> being triggered when water in tank <NUM> is at or below an intermediate water level, and level sensor <NUM> being triggered when the water in tank <NUM> is at or below a minimum water level. Outflow from storage tank <NUM> then occurs through check valve <NUM> and the inlet of pump <NUM>. Concentrate flow is discharged to drain <NUM> via a flow to and through solenoid valve <NUM> and then through check valve <NUM> and through valve <NUM> of solenoid valve <NUM>. Precise water product flow <NUM> and thermal stability, under all circumstances, is provided via input signals from sensor <NUM>, temperature sensor 222B, pressure sensor <NUM>, flow sensor <NUM>, pressure sensor PS3 at outlet of return <NUM> and an algorithm uploaded to controller <NUM>, which precisely controls the operations of solenoid valve <NUM> (and individual valves 271a and 271b), inline heater <NUM> and thermocouple <NUM>, and pump <NUM>.

In the above embodiments, controller <NUM> is communicatively coupled to a plurality of solenoid control valves and with VFD pump <NUM> and as a system regulate flow and water pressure applied to RO membrane unit <NUM> and thus production of heated purified water flow into and out of the inlet of external heat tolerant device <NUM> (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 <NUM>.

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 <NUM> 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 <NUM>. In a related embodiment, water from the storage tank <NUM> can also be used to cool the system. Water from city feed <NUM> flows through main manifold <NUM> and is pumped with pump <NUM> through membrane <NUM> through to product outlet <NUM> (and through heater <NUM>) and returns through return port <NUM> and back through to storage tank <NUM>. Waste water from membrane <NUM> also flows back through main manifold <NUM> and through solenoid valve <NUM> and check valve <NUM> and through solenoid valve <NUM> and out to drain outlet <NUM>.

In a related embodiment, the heat forward system <NUM> uses storage tank <NUM> in either break tank mode or it can go directly into a multimode configuration. The heat forward process typically operates at temperatures above <NUM> kelvin (<NUM>°F) and can commence as soon as the water temperature is above <NUM> kelvin (<NUM>°F). Once the water temperature reaches its target temperature, it locks onto the target and begins flow stability within system <NUM>. A target temperature of system <NUM> is dependent on the feed water temperature provided to as system <NUM> 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 <NUM> will be able to produce in a certain timeframe as cold water takes longer to permeate membrane <NUM> or <NUM> than does warmer water. A key advantage is that system <NUM> 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) <NUM>), system <NUM> can estimate generating about <NUM>/minute of flow of product water. Hence, manipulating SV5 and slowing down the operation of pump <NUM> helps to control any potential pressure buildup in system <NUM>. If there is a disturbance in the water temperature, controller <NUM> 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 <NUM>. Further, system <NUM> shuts down if there is a loss of power as system <NUM> is configured for manned operation. In one example embodiment, system <NUM> can reach a target temperature of about <NUM> kelvin (<NUM>°F) for heat forward sanitization or for the self-heating process in about <NUM> minutes depending on the size hose or conduit used in the external connection portion and the temperature of the feed water being used. System <NUM> 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 in this example embodiment, RO system <NUM> includes a low flow velocity sensor assembly <NUM> which senses if flow in the line is substantially slowing down, and also protects an inline heater <NUM>, is communicatively coupled to controller module <NUM> and VFD pump <NUM> that is configured to initiate VFD pump stabilization should there be fluctuations in water pressure from city feed <NUM>. In this example embodiment, RO system <NUM> also includes an integral thermal sensor <NUM> that quickly raises the temperature of RO water provided by VFD pump <NUM> and membrane <NUM> 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 <NUM> and reduces power requirements as only the water that is needed is heated and not the entire storage tank <NUM> as in other RO systems. In this example embodiment of RO system <NUM> there is also included a high flow pressure regulator <NUM> that is communicatively coupled to controller module <NUM> and which regulates water pressure from city feed <NUM> and flow sensor <NUM> that monitors an outlet <NUM> of VFD pump <NUM> flowing into RO membrane unit <NUM>.

Further in the above example embodiment, upon sensing an overheating condition in system <NUM>, controller <NUM> 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 <NUM> 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 <NUM>, upon the heated purified water temperature fluctuating above or below a defined temperature range and being sensed and acknowledged by controller <NUM>, controller <NUM> 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 <NUM> and associated sensors assists in keeping system <NUM> stable and in control.

One of the main advantages of system <NUM> and the heat forward method and system taught herein is that fluid outflow from product port <NUM>/<NUM> and any other port or orifice of system <NUM> is controlled and monitored by controller <NUM>, allowing system <NUM> to work independently of the dialysis machine (or any other external device) that system <NUM> is connected to. When solenoid valve (S5) <NUM> leading to tank <NUM> but also connected with return <NUM> at the other end, is open and the fluid flow from external device <NUM> stops, then controller <NUM> senses that external device <NUM> is longer taking water (or the internal solenoid valve is closed and/or their internal tank is full), solenoid valve <NUM> then adjusts the return path and begins to direct water back through to return port <NUM> and back to tank <NUM>. This capability also allows system <NUM> to control the outflow of heated water by using SV5a to direct water to tank <NUM> or using SV5 to direct water to drain <NUM>. In this example, such outflow control if facilitated by the use of a Y-connector to the hose going from product port <NUM> to external device <NUM> (one branch) and to return port <NUM> (second branch).

<FIG> is a schematic view of RO system <NUM> operating to provide an external device (e.g., dialysis machine) with pure water. Note from a line code <NUM> 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 <NUM> out and there is an intermittent water flow <NUM> from the return port <NUM>. There is also a conditional water flow 330A that flows to storage tank <NUM> and a water flow 330B that flows out to drain port <NUM>. An alternate flow is also provided through solenoid valve SV5 from return <NUM> out to either tank <NUM> or out to drain <NUM>. Waste water can also flow from membrane <NUM> through SV2 and through its orifice when the solenoid coils are not energized though to solenoid valve (SV4) <NUM> and then out to either drain <NUM> or upper path back to tank <NUM>. Finally, there is a water flow <NUM> from city feed <NUM> back to storage tank <NUM>.

<FIG> and <FIG> is a schematic view of the RO system running a purge operation <NUM> of a pure water storage tank and refilling the pure water storage tank with pure water, respectively. In this example embodiment, storage tank <NUM> is first emptied then pump <NUM> is engage via controller <NUM> to energize solenoid valve SV1 to allow city water <NUM> to flow through to pump <NUM>. <FIG> the check valve is open for storage tank purge but is closed in <FIG> when refilling storage tank. Tank <NUM> is then refilled and water is pushed around the various conduits of system <NUM> to continue with purge operation. Once level switch (LSI2) <NUM> is activated at about half of the tank refill level, controller <NUM> is signaled to stop pushing water through system <NUM>. Once purge is complete, chemical cleaning/purge or self-heat cleaning can continue.

<FIG> is a schematic view of RO system <NUM> recirculating heat sanitizing water through components of the RO system. In this example embodiment, check valve <NUM> closes off line <NUM> from membrane <NUM>, check valve <NUM> closes off any back from the outgoing product water line and check valve <NUM> closes off any backflow from the return line. Storage tank level sensor <NUM> stays on to measure the storage tank level to ensure there is sufficient water to run the heat circulation process.

Claim 1:
A method for sanitizing with heated purified water an external heat tolerant device 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, the method comprising:
(a) 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;
(b) initiating a variable frequency drive (VFD) pump coupled to the RO membrane unit inlet 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
(c) 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.