Reverse osmosis water system with heat forward function

A reverse osmosis (RO) system is described that is connectable to a dialysis machine and is capable of using heated purified water to clean and disinfect an external connection section or portion disposed between the RO system and the dialysis unit (or any other external heat tolerant device) without forming a closed loop system between both systems before and during a heat forward process. This can be accomplished without the need for direct/indirect or wired/wireless communication with the dialysis unit or the need to introduce a chemical cleaner or process that would require further rinsing after chemical disinfection.

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.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the Figures,FIGS.1and2illustrate 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 system100purifies water provided by a feed water supply110for use in various applications, such as dialysis. The RO system100possesses 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 system200more specifically discloses the heat forward function and the associated flows with the controlling components in the system. A variable frequency pump120provides the pressure required to push water through the RO membrane and against a fixed orifice, while fluid controls along with a controller160provide a means of managing flow rates and pressures. In particular, RO system100provides for sanitizing with heated purified water, with the RO system having an inlet112for receiving potable water from an external (city) potable feed water supply110and an internal storage tank180for 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 unit140that receives water from potable feed water supply110and which purifies the water and delivers the purified water through delivery conduit142(and delivers concentrate or waste water through conduit141and main manifold115) and eventually provides purified product water at product water outlet150. RO system100also includes a return outlet170for directing excess or unused product water through manifold115to storage tank180or to a drain outlet130. Drain outlet130can also receive waste water from membrane140. The drain output130may be connected to a receptacle or other system for proper disposal of the drain fluid.

In this example embodiment, RO system100also includes controller module160which activates a heat sanitizing cycle within the sanitizing system and that is programmed to operate the components of the system100to provide various functionalities (e.g., water purification, sanitization, etc.). Controller module160further includes a heating power management control circuit161programmed to help isolate part of RO system100and 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 (device256in system200) of an overall system (not shown in system100). 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 system100and 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 controller160and260and 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 controller160/260so as to limit the current. Further, a control of the pump speed of pump120/220or control of the flow path also within the purview of the capabilities of controller160/260.

Referring again toFIGS.1and2, in this example embodiment of RO system100, a series of solenoid valves (SV), check valves (CK) and conductivity sensors (Q) are housed in main manifold115to 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 withFIG.1. Solenoid valve (SV1)116is 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)126is 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)128is 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)172is 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)185is 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 valve126opens to help configure RO system100at a predetermined condition of flow during the heat forward process.

Referring again toFIGS.1and2, a series of check valves are provided that operate with the various solenoid valves and controller160to 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 line150. A check valve CK3, which is located between the internal tank180and drain130, 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 pump120, prevents RO feed water110from being fed into internal tank180.

RO system100also includes a series of conductivity sensors (Q) which are in communication with controller160as well as the solenoid valves and check valves to control flows within system100. An RO feed water conductivity sensor (Q1)118which monitors the quality and temperature of the inlet water to pump120. 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 membrane140. 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 system100display and this sensor is also temperature compensated. An RO feed water pressure sensor (PS1) (near regulator114) monitors the incoming water pressure to the RO system100and 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)124monitors the output of the pump120and 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 return170) 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)114controls the incoming feed pressure to the RO system when solenoid valve (SV1)116is open. A flow sensor (FS1)193switch monitors the flow of product water from the membrane140, thereby displaying flow on the RUN screen or the ANALOG screen. A thermocouple (TC/F)191, which is located near the heater190, 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 system100also includes a variable frequency drive (VFD) pump120that is coupled to an RO membrane unit inlet139and that is communicatively coupled to controller module160. Pump120generally controls the fluid pressure through RO system100and generally controls water pressure input to membrane140. In some embodiments, pump120maybe 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 pump120so as to shut down system100if an overpressure condition is detected. In this example embodiment, VFD pump120is designed to operate at a first pumping rate until an average feed water supply temperature and pressure (provided by city feed110) 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 tank180to stabilize VFD pump120from pressure fluctuations in external feed water supply110. RO system100further includes a solenoid valve and manifold assembly115that is communicatively coupled to controller module160and to VFD pump120, the main manifold being configured to control flow of feed water supply110via line112and the purified water provided by membrane unit140via delivery conduit or outlet142.

Referring again toFIG.1, during a normal water purification cycle, the solenoid valve185(and alternatively valve116) cycles depending on the level of water in the tank180. During heating and chemical sanitization modes of operation, described in more detail below, the solenoid valve116operates independently to isolate the pump120. The quality sensor122C and temperature sensor122B monitor the quality and temperature of the product water, respectively, after the pure product water exits membrane140. The product water quality measured by the quality sensor122C can be reviewed (e.g., on a screen associated with the system100) during normal operation. The input of a check valve144is connected between the output of the membrane140via the valve body122A, and an output of check valve144is connected to the input of internal tank180. Check valve144is configured to prevent backflow of water in internal tank180into the product water provided to the product water output150and simply blocks back flow into the divert valve122a. In another part of the system, a solenoid valve172aprovides fluid flow resistance during normal operation to the unused product water returning from the external connection170. Check valve174is configured to prevent backflow of water in internal tank180into return water input170. In some embodiments, the solenoid valve172provides a backpressure to maintain the product water at a pressure of approximately 35 psi (0.241 MPa). Check valve184is configured to prevent backflow of water in internal tank180from city feed water supply110. Check valve154is configured to provide a flow path into tank180for waste flow if the drain130becomes blocked or restricted. Check valve184is at an outlet of tank180and prevents pressurized potable water from entering tank180when valve116is open and feeding pump120directly. Check valve174is connected between drain output130and valve172and is configured to prevent back flow from drain130into valve172and or provide a restricted forward flow from valve172to drain130; dependent on process conditions. A solenoid valve185is controllable to provide potable water flow into tank180; depending on process conditions.

In some embodiments, RO membrane140is 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. Membrane140may have a variety of configurations including, for example, spiral wound or hollow fiber configurations. Outputs141passes through product water manifold122into the larger main manifold115and valve126at125and with the valve126aclosed flows through an internal orifice to valve128. The flow through142enters product water manifold122and valve122aand flows to192or144depending on process and water quality conditions. A check valve129prevents backflow from the storage tank and recirculating into valve126b.

In operation, a purified water flow control system as part of RO system100supplies and regulates the purified water flow as well as activates a heating power application system from the heat power module161. Heater element190applies 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) pump120that 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 pump120transitions to a second pumping rate. VFD pump120stabilization is initiated as a flow volume measuring sensor193coupled 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 pump120from water pressure fluctuations in the external potable water supply110by drawing water from the internal storage tank180via 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.

Controller160initiates raising the temperature of the regulated purified water flow provided by VFD pump120via 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, controller160varies 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. Controller160further 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. Controller160also 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 tank180.

Controller160provides 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, controller160initiates 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, controller160initiates 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. Controller160also allows the user to manually activate an exit process of the RO system100thereby 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, controller160initiates activating a heating power application system of heat power controller161including 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. Controller160controls the flow of the purified water in RO system100before 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, controller160assists in operating RO system100with low inlet pressure from the external feed water supply without shutting down system100(as well as system200below).

Referring now toFIG.2, more specifically there is illustrated a schematic view of an example embodiment of a RO water purification system200, illustrating the fluid flows for the heat forward process of system100, (having a heat forward capability for disinfecting an external device256. In particular, process200drives product hot water flow at the product flow outlet250via conduit255and directs return270, via conduit275, hot water via main manifold215to the storage tank280or to the drain output230. The drain output230may be connected to a receptacle or other system for proper disposal of the drain fluid. In particular, RO system200provides for sanitizing with heated purified water the external connection (“no man's land”) to the external device256with water primarily sourced from storage tank180. RO system also includes a return outlet270and conduit275for directing excess or unused product water to storage tank280or to a drain outlet230. Drain outlet230can also receive waste water from membrane240.

Referring again toFIG.2, in this example embodiment, controller module260of RO system200not only activates a heat sanitizing cycle within the sanitizing system as well as managing the heat power management control circuit261but controller260also helps to isolate part of RO system200and drive heated sanitized purified water solely through an external heat tolerant device256, such as a dialysis machine or other heat tolerant device or heat tolerant section or portion of an overall system, which is coupled to system200. Upon the user of RO system200selecting the heat forward process via the system GUI (user interface), pump220ramps up mainly flowing concentrate through solenoid valve226, through check valve229and inlet valve227and out through drain230. Pump220further starts moving some volume of pure product water through flow sensor293to and out of product outlet250and through external device256(or the external connection). After flowing through inlet of external device256, the product water returns to return270and flows through solenoid valve272via inlet valve271aand through outlet valve217b, and then flows through check valve274and out to drain230or flows to tank280. Once flow is sensed by flow sensor293, pump220continues to ‘tune’ for a flow rate pre-determined by flow sensor293and controller260as a function of the temperature measured at quality sensor218. Once the target fluid flow rate is stabilized, pump220locks its pumping action conditions. Thereafter, with pump220in a locked mode, controller260initiates the heating of product water flow250by a signal to heating power module261which in turn signals inline heater290and thermocouple291to initiate heating and heat monitoring.

During all of the heat forward processes (including start-up, running and heat forward cool down), city feed water210is always provided via line212, and through solenoid valve285, and fluid levels usable in the RO system are sensed by water level sensors281,282,283of storage tank280. Internal tank280receives water from check valve244and/or the return input270. The level of the fluid in internal tank280is measured by the level sensors281,282and283with level sensor281being triggered when water in tank280is at or above a maximum water level, level sensor282being triggered when water in tank280is at or below an intermediate water level, and level sensor283being triggered when the water in tank280is at or below a minimum water level. Outflow from storage tank280then occurs through check valve284and the inlet of pump220. Concentrate flow is discharged to drain230via a flow to and through solenoid valve226and then through check valve229and through valve227of solenoid valve228. Precise water product flow250and thermal stability, under all circumstances, is provided via input signals from sensor218, temperature sensor222B, pressure sensor224, flow sensor293, pressure sensor PS3at outlet of return270and an algorithm uploaded to controller260, which precisely controls the operations of solenoid valve228(and individual valves271aand271b), inline heater290and thermocouple291, and pump220.

In the above embodiments, controller260is communicatively coupled to a plurality of solenoid control valves and with VFD pump220and as a system regulate flow and water pressure applied to RO membrane unit240and thus production of heated purified water flow into and out of the inlet of external heat tolerant device256(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 system200.

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 system200will 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 feed210. In a related embodiment, water from the storage tank280can also be used to cool the system. Water from city feed210flows through main manifold215and is pumped with pump220through membrane240through to product outlet250(and through heater290) and returns through return port270and back through to storage tank280. Waste water from membrane240also flows back through main manifold215and through solenoid valve226and check valve229and through solenoid valve228and out to drain outlet230.

In a related embodiment, the heat forward system200uses storage tank280in 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 system200. A target temperature of system200is dependent on the feed water temperature provided to as system200determines 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 system200will be able to produce in a certain timeframe as cold water takes longer to permeate membrane140or240than does warmer water. A key advantage is that system200can 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), system200can estimate generating about 200 ml/minute of flow of product water. Hence, manipulating SV5 and slowing down the operation of pump120helps to control any potential pressure build-up in system200. If there is a disturbance in the water temperature, controller260along with the various temperature sensors and solenoid valves will drive promptly towards system control and stability by monitoring the current fluid flow within system200. Further, system200shuts down if there is a loss of power as system200is configured for manned operation. In one example embodiment, system200can 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. System200will 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 system200includes a low flow velocity sensor assembly203which senses if flow in the line is substantially slowing down, and also protects an inline heater290, is communicatively coupled to controller module260and VFD pump220that is configured to initiate VFD pump stabilization should there be fluctuations in water pressure from city feed210. In this example embodiment, RO system200also includes an integral thermal sensor291that quickly raises the temperature of RO water provided by VFD pump220and membrane240to 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 system200and reduces power requirements as only the water that is needed is heated and not the entire storage tank280as in other RO systems. In this example embodiment of RO system200there is also included a high flow pressure regulator214that is communicatively coupled to controller module260and which regulates water pressure from city feed210and flow sensor293that monitors an outlet221of VFD pump220flowing into RO membrane unit240.

Further in the above example embodiment, upon sensing an overheating condition in system200, controller260monitors 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, controller260proceeds 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 system200, upon the heated purified water temperature fluctuating above or below a defined temperature range and being sensed and acknowledged by controller260, controller260proceeds 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 controller260and associated sensors assists in keeping system200stable and in control.

One of the main advantages of system200and the heat forward method and system taught herein is that fluid outflow from product port150/250and any other port or orifice of system200is controlled and monitored by controller160, allowing system200to work independently of the dialysis machine (or any other external device) that system200is connected to. When solenoid valve (S5)272leading to tank280but also connected with return270at the other end, is open and the fluid flow from external device256stops, then controller260senses that external device256is longer taking water (or the internal solenoid valve is closed and/or their internal tank is full), solenoid valve272then adjusts the return path and begins to direct water back through to return port270and back to tank280. This capability also allows system200to control the outflow of heated water by using SV5a to direct water to tank280or using SV5 to direct water to drain230. In this example, such outflow control if facilitated by the use of a Y-connector to the hose going from product port250to external device256(one branch) and to return port270(second branch).

FIG.3is a schematic view of RO system200operating to provide an external device (e.g., dialysis machine) with pure water. Note from a line code300provided on the upper left hand corner describing the various operating conditions of the RO systems described herein. In this example embodiment, product water flows310out and there is an intermittent water flow320from the return port270. There is also a conditional water flow330A that flows to storage tank280and a water flow330B that flows out to drain port230. An alternate flow is also provided through solenoid valve SV5 from return270out to either tank280or out to drain230. Waste water can also flow from membrane240through SV2 and through its orifice when the solenoid coils are not energized though to solenoid valve (SV4)128and then out to either drain230or upper path back to tank280. Finally, there is a water flow340from city feed210back to storage tank280.

FIGS.4A and4Bare schematic views of the RO system running a purge operation400of a pure water storage tank and refilling the pure water storage tank with pure water, respectively. In this example embodiment, storage tank280is first emptied then pump220is engage via controller260to energize solenoid valve SV1 to allow city water210to flow through to pump220.FIG.4Athe check valve is open for storage tank purge but is closed inFIG.4Bwhen refilling storage tank. Tank280is then refilled and water is pushed around the various conduits of system200to continue with purge operation. Once level switch (LSI2)282is activated at about half of the tank refill level, controller260is signaled to stop pushing water through system200. Once purge is complete, chemical cleaning/purge or self-heat cleaning can continue.

FIG.5is a schematic view of RO system200recirculating heat sanitizing water through components of the RO system. In this example embodiment, check valve229closes off line241from membrane240, check valve244closes off any back from the outgoing product water line and check valve274closes off any backflow from the return line. Storage tank level sensor282stays 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.