Patent Description:
Exemplary cells require approximately <NUM> volts and <NUM> amps of electrical power applied thereacross for capacitive deionization functionality. In many CapDI systems, a CapDI module includes a plurality of CapDI cells electrically arranged in a parallel configuration. Providing electrical power to such a module comprises applying the same voltage across each cell, while separately directing current through each cell. In an exemplary six cell parallel configuration, the module would require only <NUM> volts, but up to <NUM> amps of current to operate. Additionally, over time, the CapDI module continues to trap ions from the fluid flowing therethrough. Thus, many systems require an ability to expel the trapped ions from the CapDI module as the module becomes saturated with ions.

The high current demand and regeneration processes necessary of such systems often require large control and power supply systems in addition to the CapDI module to effectively operate a CapDI system. As such, it can be difficult and problematic to incorporate a CapDI system into a space-limited application, such as into a standalone piece of equipment in order to provide deionized fluid thereto.

<CIT> is directed to an operating method of an apparatus for purifying a fluid by means of an apparatus provided with an even number of cells, each of which comprises at least one lead through condenser and is electrically connected to a direct current power supply. The method includes cyclically repeating, for each cell, a charging step, in which the power supply charges the electrodes of the cell at different polarity; a service step, in which a flow of fluid to be treated is forced to pass through the electrodes of the lead through condenser of the cell with progressive build-up of the ionized particles of the fluid on the electrodes; and a regeneration step, in which the electrodes are discharged and a flow of washing fluid is forced to pass in the condenser of the cell with consequent removal of the ionized particles built up on the electrodes. Starting from the charging step of at least one first cell of the two cells, the second cell, once its service step is complete and at the start of its regeneration step, is connected in series with reverse polarity to the first cell to at least partially discharge its electrodes on the first cell in an energy recovery step. During the energy recovery step the first cell is also jointly powered by the power supply, which detects the voltage on the first cell and by means of a control card controls the supply voltage to make a preset operating voltage across the first cell.

The object of the present invention is to provide systems and methods for deionization of a fluid according to the claims. A capacitive deionization (CapDI) system comprises a CapDI module having a fluid inlet and a fluid outlet; a fluid reservoir including a conductivity sensor for determining the conductivity of the fluid configured to provide information regarding the remaining ionization in the fluid after passing through the CapDI module; and a control board comprising a controller, a conductivity sensor interface coupled to the controller and providing communication between the controller and the conductivity sensor, a switching regulator coupled to the controller, a power MOSFET polarity circuit coupled to the switching regulator, and a module connector connectable to the CapDI module and coupled to the power MOSFET polarity circuit. The power MOSFET polarity circuit is configured to provide bidirectional electrical power to the CapDI module via the module connector. The switching regulator provides electrical power to the power MOSFET polarity circuit. The controller is configured to control the providing of electrical power from the switching regulator to the power MOSFET polarity circuit based on the communication between the controller and the conductivity sensor, wherein the controller is configured to increase the current applied to the CapDI module, if a measured conductivity is above a threshold by increasing an applied voltage from the controller to the switching regulator and the controller is configured to decrease the current applied to the CapDI module, if the measured conductivity is below the threshold. The controller is configured to collect conductivity information over a length of time and to calculate an average of the measured conductivity before comparing the conductivity to the threshold. The control board is not larger than <NUM> (<NUM> inches) by <NUM> (<NUM> inches) in dimension. The CapDI System is configured to deionize fluid via the CapDI module and direct deionized fluid to a fluid reservoir for future use. The CapDI system further comprises a first valve coupled between the fluid outlet and a use device; and a second valve coupled between the fluid outlet and a drain. Further a method for treating a fluid using this CapDI system is provided according to the claims.

Exemplary systems include a capacitive deionization (CapDI) module positioned in a fluid flow system and configured to deionize the fluid flowing therethrough. The CapDI module can include a plurality of CapDI cells arranged in series with one another. Thus, the plurality of cells can be powered using comparatively low current when compared to cells arranged in parallel as discussed above.

Systems can include a power MOSFET polarity circuit, such as a solid state H-bridge circuit, configured to provide bidirectional electrical power to the CapDI module. In various embodiments, the power MOSFET polarity circuit can be adjusted in order to change the polarity of electoral power provided to the CapDI module. A switching regulator can be configured to provide power to the power MOSFET polarity circuit. In some examples, a controller is configured to control the providing of the electrical power from the switching regulator to the power MOSFET polarity circuit. The controller can be in communication with a sensor, such as a conductivity sensor, and can control the providing of electrical power to the MOSFET polarity circuit based on communication between the controller and the sensor.

In some embodiments, the controller can compare a conductivity measured using a conductivity sensor to a conductivity threshold. In some such embodiments, in the condition that the detected conductivity exceeds the threshold, the controller can act to increase the electrical power applied from the switching regulator to the power MOSFET polarity circuit. In still further examples, if the detected conductivity is lower than the threshold, the controller can act to decrease the electrical power applied to the power MOSFET polarity circuit In some such examples, the controller acts to adjust the power applied to the power MOSFET polarity circuit by adjusting an electrical potential applied to the switching regulator.

In some examples, systems can include a first valve coupled between the CapDI module and a use device and a second valve coupled between the CapDI module and a drain. In some such examples, during use, electrical power can be applied to the CapDI module from the power MOSFET polarity circuit at a first polarity while the first valve permits the flow of fluid to the use device. Applying power at the first polarity can cause the CapDI module to electrically capture ions from the fluid, thereby creating a deionized fluid to flow toward the use device. During an exemplary process, the first valve can be closed to prevent fluid from flowing from the CapDI module to the use device and the second valve can be opened to allow fluid to flow from the CapDI module to the drain. The power MOSFET polarity circuit can be adjusted to apply electrical power in a second polarity opposite the first to the CapDI module. Such an exemplary process can be performed in response to a detected regeneration condition.

The following description provides some practical illustrations for implementing various embodiments of the present invention. Unless otherwise noted, illustrations of various aspects of the disclosure are not necessarily drawn to scale. Examples of constructions, materials, dimensions, and manufacturing processes are provided for selected elements, and all other elements employ that which is known to those of ordinary skill in the field of the invention.

<FIG> is a schematic diagram of an exemplary CapDI system according to some embodiments. <FIG> shows a representation of an exemplary CapDI system <NUM> including CapDI module <NUM> having a fluid inlet <NUM> and a fluid outlet <NUM>. In the illustrated embodiment, the CapDI module <NUM> receives fluid from a cold water line <NUM> via the fluid inlet <NUM>. In general, the fluid inlet <NUM> can receive fluid from any source appropriate for the desired use of the fluid. In the illustrated embodiments, the CapDI module <NUM> is incorporated into a system comprising various components such as a filter <NUM>, a parallel arrangement of flow restrictors <NUM>, and valves 114a, 114b located in parallel lines 113a, 113b, respectively. In some systems, a plurality of lines such as 113a and 113b can be selectively placed in fluid communication with the fluid inlet <NUM> of the CapDI module <NUM> for various operations and/or procedures using the module <NUM>. Valves 114a, 114b, such as solenoid valves, for example, can be incorporated into one or more such lines in order to selectively couple the lines to the module <NUM> and control fluid flow rate, for example. In general, any number of various components can be placed in line prior to the fluid inlet <NUM> of the CapDI module <NUM> in order to prepare the fluid for its intended use. The CapDI module <NUM> receives and performs a deionization process on the fluid.

The fluid outlet <NUM> of the CapDI module <NUM> is shown comprising two outlet ports <NUM>, <NUM>. In some systems, fluid from the CapDI module can be directed to a use device for using the deionized fluid or to a drain. Use devices can include, for example, a dishmachine, a cooling tower, water softening applications, or others. The CapDI system <NUM> is configured to deionize fluid via the CapDI module <NUM> and direct deionized fluid to a fluid reservoir <NUM> for future use. The CapDI module can comprise a plurality of outlet ports, such as in the embodiment shown in <FIG>, for directing fluid to one of a plurality of possible destinations. In some such embodiments, the CapDI module <NUM> can include a system of one or more valves or other fluid diverters therein for directing fluid as desired. In some configurations, a CapDI system includes a series of one or more external valves coupled to one or more outlet ports of the CapDI module <NUM> to control the destination of fluid coming from the outlet ports. These valves can include any appropriate type of valve for controlling fluid flow, such as solenoids, <NUM>-way valves, and other flow limiting devices.

In the illustrated embodiment, the first outlet port <NUM> of the CapDI module <NUM> is in fluid communication with a first solenoid valve <NUM> and a fluid reservoir <NUM> for a use device. The fluid reservoir <NUM> can comprise a fluid level detector <NUM>, represented in the illustrated embodiment a high float <NUM> and a low float <NUM>, for determining information regarding the amount of deionized fluid in the fluid reservoir <NUM>. Any appropriate detector for detecting information about the amount of fluid in the fluid reservoir <NUM> or use device can be used. In some embodiments, the fluid reservoir <NUM> includes a conductivity sensor <NUM> for determining the conductivity of the fluid. Conductivity sensor is used to provide information regarding the remaining ionization in the fluid after passing through the CapDI module <NUM>. In various embodiments, other appropriate sensors can also be used, such as an optical sensor, a temperature sensor, a flow meter, pH sensor, a total dissolved solid (TDS) sensor, and the like. The second outlet port <NUM> is shown in fluid communication with a second solenoid valve <NUM> and a drain <NUM>.

From a system level, the CapDI module <NUM> can deionize a fluid for use with the use device. Fluid from a source such as a cold water line <NUM> can be directed through various components such as a filter <NUM> to the CapDI module <NUM>, which can act to deionize the incident fluid. The deionized fluid can be directed toward a use device which can include a fluid reservoir <NUM> and a fluid level detector <NUM>. Alternatively, the fluid from the CapDI module <NUM> can be directed toward a drain <NUM>. The direction of the fluid from the CapDI module <NUM> can be dictated by valves <NUM> and <NUM>.

The CapDI module <NUM> acts to deionize a fluid by way of electrically removing ions therefrom. In general, an electric charge is applied between capacitive surfaces between which fluid flows. The applied charge creates an electric field that causes ions to migrate toward one charged surface or the other, where they can be trapped in the capacitive surface or a separate surface designed for trapping ions. In some embodiments, the separate surface is designed for trapping only one polarity of ions, while being impermeable to the other.

<FIG> are exemplary diagrams of a basic CapDI configuration such as may be used in a CapDI module. In the illustrated embodiment, a charge is provided to opposing capacitive surfaces <NUM> and <NUM> from a source <NUM>. Source <NUM> is shown as being a DC source, however, in various embodiments, more complicated power source arrangements can be used. In the illustrated example, a first capacitive surface <NUM> is held at a positive charge with respect to a second capacitive surface <NUM>. When the charge is applied across the surfaces, a negatively charged ion <NUM> in a fluid therebetween will migrate toward the first capacitive surface <NUM> (the more positive surface), while a positively charged ion <NUM> in the fluid will migrate toward the second capacitive surface <NUM> (the more negative surface), as illustrated by the arrows in <FIG>.

In some embodiments, first <NUM> and/or second <NUM> capacitive surfaces comprise a porous material for trapping ions <NUM>, <NUM> therein. In alternative embodiments, first <NUM> and second <NUM> capacitive surfaces comprise a first <NUM> and second <NUM> porous layer, respectively, for trapping ions attracted to the respective capacitive surfaces. In some embodiments, the surface for trapping ions comprises a membrane that selectively allows ions with charge of a certain polarity to pass therethrough. As charge (i.e., ions) migrates through the fluid to respective capacitive surfaces, current flows through the fluid. Accordingly, current flowing to/through the capacitive surfaces and the CapDI module <NUM> is indicative of the number of ions being removed from the fluid.

Over time and with use, the components of the CapDI module that trap ions therein (e.g., porous capacitive surfaces <NUM>, <NUM> or other porous layers <NUM>, <NUM>) can become saturated with ions. Accordingly, it can be desirable to be able to rid such components of ions in order to regenerate the CapDI module <NUM>. For example, with reference to <FIG>, if the polarity of the power source <NUM> were reversed, a negative ion <NUM> trapped in, for example, the first porous layer <NUM> will be repelled away from the first capacitive surface <NUM> (the more negative surface) and into the fluid, while a positive ion <NUM> trapped in, for example, the second porous layer <NUM> will be repelled away from the second capacitive surface <NUM> (the more positive surface) and into the fluid. If the first <NUM> and second <NUM> porous layers comprise selective membranes as mentioned, ions repelled into the fluid cannot simply be trapped in the opposite porous layer, but rather stay in the fluid. Thus, if fluid is flushed through the CapDI module <NUM>, previously trapped ions will be flushed from the module <NUM>, creating room for the further deionization of fluid. Thus, the CapDI module <NUM> comprises at least two modes of operation - a purification mode in which ions are removed from the fluid and trapped in either capacitive surfaces or other porous layer, and a regeneration mode, in which trapped ions are flushed from the CapDI module <NUM>.

As shown in <FIG>, the exemplary CapDI system <NUM> includes a source of electric power to the CapDI module <NUM> to effectively capture ions from a fluid flowing therethrough. As such, with reference back to <FIG>, the CapDI system <NUM> includes a power supply line <NUM> for providing electrical power to the CapDI module <NUM>. Power supply line <NUM> can provide a specified amount of voltage and/or current to the CapDI module <NUM>. In some embodiments, the CapDI module <NUM> operates at approximately 10VDC and between approximately zero and <NUM> amps of current.

In some embodiments, the CapDI module <NUM> comprises a plurality of CapDI cells, each comprising electrodes and possibly porous surfaces such as shown in <FIG>. CapDI cells can be arranged electrically in series or in parallel to form a CapDI module. In an exemplary embodiment, a CapDI module comprises six CapDI cells, each with an operating voltage of approximately <NUM>. 5VDC and an operating current of up to 15A. When arranged in parallel, the CapDI module as a whole can operate at <NUM>. 5VDC (applied across each CapDI cell in parallel), but can requires up to <NUM> x <NUM> = 90A to operate at full capacity. However, a CapDI module comprising the same cells arranged in series can operate at <NUM> x <NUM> = 9VDC but with a maximum operating current of only 15A. Accordingly, in some embodiments, CapDI cells are arranged in series to construct a CapDI module to reduce the amount of current required to operate the CapDI system.

In some embodiments, the CapDI system includes a control board for controlling various aspects of the CapDI system and providing electrical power to the CapDI module. <FIG> is a schematic diagram of an exemplary control board for use with some embodiments of the invention. In the illustrated embodiment, the control board <NUM> comprises module connector <NUM> for electrically coupling the CapDI module <NUM> to the control board <NUM>. The board <NUM> further includes a switching regulator <NUM> and a power MOSFET polarity circuit <NUM> connected to the module connector <NUM>. During operation of the CapDI system, the switching regulator <NUM> provides electrical power to the CapDI module <NUM> via the power MOSFET polarity circuit <NUM> and the module connector <NUM>.

The switching regulator <NUM> can act to regulate the voltage applied to the CapDI module <NUM>. In some embodiments, a certain voltage (e.g., <NUM> VDC) is applied at a single power input <NUM> to the control board <NUM>. However, such a voltage may be inappropriate for all uses on the board or system. For example, in some configurations, the CapDI module <NUM> is configured to operate at <NUM> VDC. In such an embodiment, the switching regulator <NUM> can be configured to receive power from the single power input <NUM> and provide a regulated output of approximately <NUM> VDC to the CapDI module <NUM> via the power MOSFET polarity circuit <NUM> and the module connector <NUM>. The switching regulator <NUM> can additionally source current to the CapDI module <NUM> as ions are trapped in the porous layers <NUM>, <NUM> or capacitive surfaces <NUM>, <NUM>. In some embodiments, the switching regulator <NUM> is adjustable, in that the switching regulator can receive an input corresponding to in output current limit. That is, the switching regulator <NUM> can limit the current output to the power MOSFET polarity circuit <NUM> based on a received input signal. Exemplary switching regulators can comprise 150W adjustable switching regulators.

The power MOSFET polarity circuit <NUM> can include one or more MOSFETS, and be configured to receive electrical power from the switching regulator <NUM> and direct it to the CapDI module <NUM> via the module connector <NUM>. The power MOSFET polarity circuit <NUM> can further output the power to the module connector <NUM> in either of a first or a second polarity. Thus, the power MOSFET polarity circuit <NUM> is configured to enable purification mode or regeneration mode of the CapDI system <NUM> while receiving electrical power from the switching regulator <NUM> in only a single polarity. Accordingly, the switching regulator <NUM> need only supply electrical power in a single direction. In some examples, power MOSFET polarity circuit <NUM> comprises a plurality of power MOSFET devices arranged in an H-bridge configuration for bidirectional operation of the CapDI module <NUM>.

The control board <NUM> of <FIG> further includes a valve control mechanism <NUM> for controlling valves in the CapDI system <NUM>. For example, valve control mechanism <NUM> can be configured to interface with any or all of valves 114a, 114b, <NUM> and <NUM> of the CapDI system <NUM> shown in <FIG> to direct fluid in a desired manner. In some examples, any or all of valves 114a, 114b, <NUM> and <NUM> comprise solenoid valves, or other electrically actuated valves. In such embodiments, valve control mechanism <NUM> can selectively provide electrical power to the valves. Valve control mechanism <NUM> can be electrically coupled to power input <NUM> for receiving power to direct toward appropriate valves in the CapDI system <NUM>.

In some embodiments, components on the control board <NUM>, and resultantly other components of the CapDI system <NUM>, are controlled by a controller <NUM>, which can be included on the control board <NUM>. Controller can include, for example, a microcontroller or other device capable of receiving signals and outputting signals based on the received signals. In some configurations, controller <NUM> is sized such that it can be positioned on a control board <NUM>. In some embodiments, controller <NUM> can be in communication with several components of the control board <NUM>. For example, the controller can be in communication with valve control mechanism <NUM> in order to control the opening and closing of valves at various times during operation of the CapDI system <NUM>. In some configurations, the controller can be in communication with the fluid level detector <NUM> in a fluid reservoir <NUM> in a use device. Accordingly, the controller <NUM> can receive information regarding the level of fluid in the fluid reservoir <NUM> and control valves to direct fluid through the CapDI system <NUM> to the reservoir <NUM> if necessary.

In some examples, controller <NUM> can be in communication with the power MOSFET polarity circuit <NUM> to define the polarity of power applied to the CapDI module <NUM> from the switching regulator <NUM>. For example, in the case of an H-bridge power MOSFET configuration, controller <NUM> can act to "turn on" or "turn off" various MOSFETs in the power MOSFET polarity circuit <NUM> to define the polarity of the electrical power delivered to the CapDI module <NUM>. In some embodiments, controller <NUM> can output a voltage in order to affect the power transmission through the MOSFETs in the power MOSFET polarity circuit <NUM>. Controller <NUM> can provide appropriate voltages to control various MOSFETs in response to a received signal. Such a signal can be initiated, for example, by a sensor, timer, user interface, or any other component appropriate for providing a signal to the controller <NUM>.

For example, in some configurations, controller <NUM> can receive signals from a sensor, timer, controller or other system component indicative of the desired mode of operation for the CapDI module. If the module <NUM> is to be operated in purification mode (to deionize a fluid), the controller <NUM> can apply appropriate voltage to the power MOSFET polarity circuit <NUM> to direct electrical power in a first polarity from the switching regulator <NUM> to the module <NUM>. If the module is to be operated in regeneration mode, the controller <NUM> can apply an appropriate voltage to the power MOSFET polarity circuit <NUM> to direct electrical power in a second polarity, opposite the first, from the switching regulator <NUM> to the CapDI module <NUM>. In some examples, applying appropriate voltage to the power MOSFET polarity circuit <NUM> for purification comprises "turning on" a first pair of MOSFETs while "turning off" a second pair to allow the flow of electricity in one direction through the CapDI module <NUM>. In such examples, applying appropriate voltage to the power MOSFET polarity circuit <NUM> for regeneration comprises "turning off' the first pair of MOSFETs while "turning on" the second pair, allowing electricity to flow in the opposite direction through the module <NUM>.

The controller <NUM> is in communication with the conductivity sensor <NUM> and can be in communication with other appropriate sensor within the system and receive signals indicative of the number of ions in the fluid after deionization in the CapDI module <NUM>. For instance, in some examples, the control board <NUM> includes an integrated conductivity sensor interface <NUM>. The conductivity sensor interface <NUM> is in communication with the controller <NUM>, and provides communication between the controller <NUM> and the conductivity sensor <NUM>. The conductivity sensor <NUM> can provide information to the controller <NUM> regarding the conductivity of the fluid, which can be indicative of the remaining ion content in the fluid. Accordingly, in some embodiments, the conductivity sensor in combination with the conductivity sensor interface can provide a closed loop feedback to the controller regarding the operation of the CapDI module.

The controller <NUM> can signal the switching regulator <NUM> to adjust the current flow or current limit through the CapDI module in order to adjust the number of ions being removed in the deionization process. In some examples, the current limit provided from the switching regulator <NUM> is determined by an input voltage thereto. The controller <NUM> can apply a voltage to the switching regulator <NUM> in order to allow current to flow therefrom, and can adjust the voltage applied thereto to adjust the current allowed to flow from the switching regulator <NUM> to the CapDI module <NUM>. In some examples, the controller <NUM> adjusts the current allowed to flow from the switching regulator <NUM> to the CapDI module in response to signals from the closed loop feedback provided by the conductivity sensor and the integrated conductivity sensor interface.

As has been so far described, the controller <NUM> can communicate with various sensors and other components in the CapDI system <NUM> and on the control board <NUM>. In some embodiments, the controller <NUM> is configured to perform methods in response to various parameters sensed by sensors in the system. Such methods can be, for example, embodied on a non-transitory computer-readable medium embedded in or in communication with the controller <NUM>, which can process and carry out instructions according to such methods.

The control board <NUM> of the CapDI system can further include a communication interface <NUM> for communicating with an external device, such as a computer or external controller. The communication interface <NUM> can include, for example, a serial communication port, a USB communication port, a wireless communication link, or any other appropriate method of control communication. Communication interface <NUM> can provide a link to an external device to, for example, initiate operation of the system via the controller <NUM> or log system information. For example, in some configurations, controller <NUM> receives a command from an external device via communication interface <NUM> to cause the controller <NUM> to perform an operation and to communicate data back to the external device. The external device can include a user interface to allow a user to initiate system operation via communication interface <NUM> and the controller <NUM>.

<FIG> is a process flow diagram illustrating exemplary operation of a CapDI system. In the process of <FIG>, electrical power is applied <NUM> to the CapDI module in a first polarity. Applying <NUM> electrical power is done by the controller outputting a voltage to the switching regulator to provide electrical power to the power MOSFET polarity circuit and thus the CapDI module. The voltage to the switching regulator from the controller can set a current limit for the output of the switching regulator. The controller can subsequently communicate with the valve control mechanism to open <NUM> an inlet valve to allow fluid to enter the CapDI and/or open <NUM> an outlet valve to direct fluid from the CapDI module to a use device, or otherwise allow fluid to flow to such a device. In some embodiments, the CapDI system need not include an inlet valve, but rather the CapDI module can receive fluid directly from a source with the prevention of flow to the use device performed by only an outlet valve. In such embodiments, opening <NUM> an inlet valve is not performed. In embodiments comprising an inlet valve, it should be noted that in various methods of operation, steps <NUM> and <NUM> of opening the inlet and outlet valves can be permuted.

The controller can determine if the use of the use device is complete <NUM>. In some examples, the use device can signal the controller that the use is complete. In other embodiments, the controller can be alerted that use of the device is complete via a user interface. If the use is complete, the controller can close <NUM> the outlet valve between the CapDI module and the use device, and operation can be stopped. If the use is not complete, then the controller can measure or detect <NUM> the conductivity of the fluid from the CapDI module with the conductivity sensor and compare <NUM> the measured conductivity with a threshold value.

In general, a more conductive fluid (i.e., a higher measured conductivity) has a higher concentration of ions in the fluid when compared to a less conductive fluid. Thus, when a measured conductivity is above the threshold, it can be interpreted that there is a higher concentration of ions remaining in the fluid than desired, and the controller increases <NUM> the current applied to the CapDI module. As discussed, increasing the current to the CapDI module can result in the removal of more ions from the fluid. Increasing the current includes increasing an applied voltage from the controller to the switching regulator If the measured conductivity is below threshold, the controllei decreases <NUM> the current applied to the CapDI module, thereby reducing the electrical load on the system.

After increasing <NUM> or decreasing <NUM> the current applied to the CapDI module, the controller can determined if the use of the use device is complete <NUM> and the same analysis is repeated until the use is complete. Thus, the controller can perform an iterative process during which the current to the CapDI module is varied in response to the measured conductivity of the sample as compared to a threshold. The threshold can be preprogrammed into the controller during factory setup, or can be set by a user via a user interface. In some examples, the threshold is adapted for a particular use or use device.

In some embodiments, additional parameters to the conductivity of the fluid, such as parameters detected by any other included sensors, can be measured and utilized in the feedback determination of increasing or decreasing the current to the CapDI module. In addition, adjusting the current to the CapDI module is performed after a certain amount of time. The controller collects conductivity over a length of time and calculate an average of the measured parameter before comparing the parameter to a threshold.

Fluid from the CapDI module is directed to a fluid reservoir for holding fluid for a use device. As described previously with respect to <FIG>, a fluid reservoir <NUM> can include a fluid level detector <NUM> such as a high <NUM> and low float <NUM>. In some embodiments, the system can include an upper and lower fluid threshold. For example, the lower threshold can represent a fluid level such that the use device can be used one more time before requiring the addition of fluid, while the upper fluid threshold can represent a fluid level such that the fluid reservoir <NUM> is full or nearly full. Thus, when the fluid is detected as being below the lower threshold, the system can initiate a fill mode in which fluid is added to the fluid reservoir <NUM> until the fluid level surpasses the upper threshold. The fluid reservoir comprises a conductivity sensor and optionally another type of sensor for measuring a parameter of the sample indicative of the ion concentration therein. Such a measurement is used to adjust operation of the CapDI module during the fluid reservoir filling process.

<FIG> is a process flow diagram illustrating exemplary operation of a CapDI system including a fluid reservoir. The process outlined in <FIG> can be performed, for example, by the controller. In the illustrated embodiment, the controller applies <NUM> electrical power in a first polarity to the CapDI module. Applying electrical power is done via the switching regulator, power MOSFET polarity circuit and module connector as described above. The controller can detect <NUM> the fluid level in the fluid reservoir via, for example, the fluid level detector, and compare <NUM> the detected level to the lower threshold. If the level is detected as being below the lower threshold, the controller can initiate <NUM> a fill mode in which deionized fluid is added to the fluid reservoir. In some embodiments, initiating <NUM> fill mode can include, for example, opening an inlet valve to allow fluid to enter the CapDI module. In other embodiments, the controller can open <NUM> an outlet valve to direct fluid from the CapDI module into the fluid reservoir to initiate <NUM> fill mode or after initiating <NUM> fill mode.

Using the conductivity sensor, the controller measures <NUM> the conductivity of the fluid in the fluid reservoir and compares <NUM> to a conductivity threshold similarly to as described with respect to <FIG>. If the measured conductivity is above the threshold, the controller increases <NUM> the current applied to the CapDI module, while if the measured conductivity is below the threshold, the controller decreases <NUM> the current. After adjusting the current, the controller can once again detect <NUM> the fluid level in the reservoir and compare <NUM> the level to the lower threshold.

If the detected fluid level is above the lower threshold, the controller can determine <NUM> if the system is in fill mode. If the system is in fill mode, the controller can compare <NUM> the fluid level to the upper threshold. If the fluid level is below the upper threshold, the fill process is not complete and the conductivity feedback sequence can be performed, including measuring <NUM> the conductivity, comparing <NUM> the conductivity to a threshold, and increasing <NUM> or decreasing <NUM> the current applied to the CapDI module. However, if the measured fluid level is above the upper threshold, the controller can close <NUM> the valve between the CapDI module and the fluid reservoir, as the fill process is complete.

If it is determined at <NUM> that the system is not in fill mode, then fill mode has not been initiated and the fluid level was not determined to be below the lower threshold. Accordingly, filling of the reservoir is not required and the fluid level determination and adjustment process is complete <NUM>. In such a situation, electrical power can be removed from the CapDI module. In general, if the detected fluid level is between the lower and upper thresholds, the outlet valve remains in its present state. That is, if the system is in fill mode, the valve between the CapDI module and the fluid reservoir is already open and remains open, since the fluid level has not yet surpassed the upper threshold. However, if the system is not in fill mode, then there is no immediate need to open the valve to fill the fluid reservoir. It should be noted that in some embodiments, power need not be applied to the CapDI module until after fill mode is initiated.

As discussed, over time, the CapDI module can become saturated with ions and become less effective at removing additional ions from a fluid flowing therethrough. Accordingly, the system can operate in regeneration mode to remove the trapped ions from the CapDI module. <FIG> is a process flow diagram illustrating exemplary regeneration of a CapDI system. The process steps of <FIG> can be performed, for example, by the controller during a regeneration of the system. After performing <NUM> one or more deionization procedures with a CapDI module in a first polarity, the controller can determine <NUM> if the module needs to be regenerated. In some embodiments, the controller is configured to regenerate the module in response to any number of detected regeneration conditions, such as: a certain amount of time has passed since a most recent regeneration, a certain number of deionization procedures have been performed, a certain volume of fluid has been run through the CapDI module since the most recent regeneration, the current limit applied to the switching capacitors has reached a predetermined level (e.g., it requires a sufficiently high predetermined amount of current to effect the desired deionization operation), or the conductivity sensor (or other sensor indicative of ionic content of the fluid) responds insufficiently to applied and/or increased electrical power applied to the CapDI module. In some instances, a regeneration procedure can be initiated at any time via a user interface.

If it is determined at <NUM> that regeneration is not needed, the system can continue to perform deionization procedures as usual. If regeneration is required, the controller can close <NUM> the outlet valve between the CapDI module and the use device if it is open, preventing the trapped ions from being directed to the use device during the regeneration procedure. The electrical power can be removed <NUM> from the CapDI module, and the power MOSFET polarity circuit can be adjusted <NUM>. Adjusting <NUM> the power MOSFET polarity circuit can include applying power to different MOSFETs within the power MOSFET polarity circuit, for example, In some embodiments, the power MOSFET polarity circuit comprises an H-bridge circuit, and adjusting <NUM> the power MOSFET polarity circuit comprises "turning off" previously conducting MOSFETs and "turning on" alternate MOSFETs such that current is allowed to flow through the adjusted power MOSFET polarity circuit and through the CapDI module in an opposite direction when compared to the deionization procedure of step <NUM>.

After adjusting <NUM> the power MOSFET polarity circuit, the controller can act to apply <NUM> electrical power to the CapDI module in a second polarity. Power can be supplied from the switching regulator, through the (adjusted) power MOSFET polarity circuit, and to the CapDI module via the module connector. For regeneration, in some embodiments, the second polarity is opposite the first. When electrical power of the second polarity is applied, ions trapped in the CapDI module are expelled into the fluid in the module. After applying <NUM> electrical power to the CapDI module in the second polarity, the controller can act to open <NUM> a second outlet valve to direct fluid from the CapDI module to a drain, such that the ions expelled into the fluid are removed from the system via the drain.

The controller can determine <NUM> if the regeneration is complete. Determining the completion of regeneration can be done in any number of ways. For example, the controller can determine regeneration is complete after flowing fluid through the CapDI module to the drain for a predetermined amount of time, or after a predetermined volume of fluid has been directed to the drain. If the controller determines that regeneration is not complete, regeneration continues. If regeneration is complete, the controller can act to close <NUM> the second outlet valve, remove <NUM> electrical power from the CapDI module, and adjust <NUM> the power MOSFET polarity circuit. Similar to step <NUM>, adjusting the power MOSFET polarity circuit at step <NUM> can include applying power to different MOSFETs within the power MOSFET polarity circuit, for example. After adjusting the power MOSFET polarity circuit, the controller can apply electrical power <NUM> to the CapDI module in the first polarity, open <NUM> the outlet valve between the CapDI module and the use device, and flow <NUM> fluid through the CapDI module toward the use device in order to perform <NUM> the deionization procedure.

The procedure of <FIG> begins with a system operating with an inline CapDI module, directing deionized fluid towards a use device. When regeneration is needed, a variety of valves are opened and closed, polarity of power applied to the CapDI module is reversed, and the regeneration fluid is directed toward the drain. Once regeneration is complete, essentially the process happens in reverse, in which valves are closed and opened, the polarity of power applied to the CapDI module is reversed again to the first polarity, and fluid is directed through the regenerated CapDI module and toward the use device. In some embodiments, the controller can determine when regeneration is needed, and when regeneration is complete, as well as control the states of a variety of valves and adjust the power applied to the CapDI module via the switching regulator. Accordingly, the process of <FIG> can be performed entirely autonomously under control of the controller. In some such examples, the fluid source, CapDI system, and use device can form a closed-loop, automated system in which the CapDI system provides deionized fluid to a use device under the control of the controller, regeneration is initiated and controlled by the controller until complete, and system use is resumed under the control of the controller.

With reference to <FIG>, some systems include a plurality of inlet lines (113a, 113b) coupled to the CapDI module <NUM>. In some embodiments, one or more of such lines comprises a valve (e.g., 114a, 114b). During a regeneration process, one or more such valves can be opened to, for example, provide a greater volume of fluid flow through the CapDI module <NUM> for effective regeneration. Valves 114a, 114b can be automatically opened, for example by the controller <NUM> controlling valve control <NUM> during an automated regeneration process, and automatically closed when the process is complete.

Embodiments of the CapDI system <NUM> can be included in various fluid processing systems or standalone machines. For example, a CapDI system <NUM> can be included as part of a dishmachine, receiving water from the water inlet for the machine and either filling a reservoir <NUM> within the dishmachine. Moreover, as previously described, arranging a plurality of CapDI cells in series allows for system operation using lower currents, allowing for the use of relatively smaller components and conductors for handling current. In addition, switching regulator <NUM> as herein described can provide sufficient electrical power for system operation coupled with a variable current limit for feedback adjustment as previously described while remaining sufficiently compact for placement on a control board. The compact power MOSFET polarity circuit <NUM>, such as a power MOSFET H-bridge circuit, operates with the switching regulator <NUM> to enable bidirectional power application to the CapDI module <NUM>, allowing for purification and regeneration modes of operation. Resultantly, the control board <NUM> provides robust control of the CapDI system while remaining sufficiently compact to be placed onboard in a use device. The control board <NUM> is no larger than <NUM> (four inches) by <NUM> (four inches) in dimension, and can include fully integrated components for operating a CapDI system.

In some embodiments, the CapDl system <NUM> can interface with an external controller via communication <NUM> on control board <NUM>. External controller can act to operate the CapDI system100 for a particular dedicated operation. Accordingly, external controller can include a memory comprising operating instructions for the controller <NUM> of the CapDI system <NUM>. For example, in some configurations, the external controller is used in a system requiring water deionized below a threshold particular to the system. Thus, the external controller can define, for example, a conductivity threshold used to dictate operation of the CapDI system. In general, the external system can control any number of operations of the CapDI system <NUM>. In some embodiments, the combination of an external controller and the CapDI controller <NUM> can combine to provide entirely autonomous operation of a CapDI system <NUM>.

The CapDI system <NUM> can be further configured to communicate with external memory, for example via communication <NUM>. External memory can be included in, for example, an external system having an external controller. In such configurations, the controller <NUM> can be configured to read from or write to the external memory. For example, the controller <NUM> can write data to an external memory regarding measured conductivity, electrical power applied to CapDI module <NUM>, the duration of CapDI module <NUM> operation, the amount of fluid deionized by CapDI module <NUM>, or any other system data that can be logged in an external memory.

In some embodiments, external memory receives CapDI system operation data from the controller <NUM> of the CapDI system. External memory can catalog and store CapDI system data for recall. Thus, a user can access past CapDI system data from the external memory for review. In some embodiments, a user can use the stored CapDI system data to analyze system operation over time, or to compare data from one system use to a past use. In other operations, CapDI system data can be recalled by a controller to determine if the system is operating correctly, needs regeneration, or for any other purpose that can be determined by a controller. It will be appreciated that the functionality of external memory as described herein can be embodied in on-board memory on the control board <NUM> of the CapDI system <NUM>. Such integrated memory can be in communication with controller <NUM> and/or an external controller via communication <NUM>.

Claim 1:
A capacitive deionization (CapDI) system (<NUM>) comprising:
a CapDI module (<NUM>) having a fluid inlet (<NUM>) and a fluid outlet (<NUM>);
a fluid reservoir (<NUM>) including a conductivity sensor (<NUM>) for determining the conductivity of the fluid configured to provide information regarding the remaining ionization in the fluid after passing through the CapD) module (<NUM>); and
a control board (<NUM>) comprising:
a controller (<NUM>);
a conductivity sensor interface (<NUM>) coupled to the controller (<NUM>) and providing communication between the controller (<NUM>) and the conductivity sensor (<NUM>);
a switching regulator (<NUM>) coupled to the controller (<NUM>);
a power MOSFET polarity circuit (<NUM>) coupled to the switching regulator (<NUM>); and
a module connector (<NUM>) connectable to the CapDI module (<NUM>) and coupled to the power MOSFET polarity circuit (<NUM>); wherein
the power MOSFET polarity circuit (<NUM>) is configured to provide bidirectional electrical power to the CapDI module (<NUM>) via the module connector (<NUM>);
the switching regulator (<NUM>) provides electrical power to the power MOSFET polarity circuit (<NUM>); and
the controller (<NUM>) is configured to control the providing of electrical power from the switching regulator (<NUM>) to the power MOSFET polarity circuit (<NUM>) based on the communication between the controller (<NUM>) and the conductivity sensor (<NUM>), wherein
the controller (<NUM>) is configured to increase the current applied to the CapDI module (<NUM>), if a measured conductivity is above a threshold by increasing an applied voltage from the controller to the switching regulator and the controller (<NUM>) is configured to decrease the current applied to the CapDl module, if the measured conductivity is below the threshold, wherein
the controller (<NUM>) is configured to collect conductivity information over a length of time and to calculate an average of the measured conductivity before comparing the conductivity to the threshold; wherein
the control board (<NUM>) is not larger than <NUM> (<NUM> inches) by <NUM> (<NUM> inches) in dimension; wherein
the CapDI System (<NUM>) is configured to deionize fluid via the CapDl module (<NUM>) and direct deionized fluid tc the fluid reservoir (<NUM>) for future use , and
further comprising: a first valve coupled between the fluid outlet (<NUM>) and a use device; and a second valve coupled between the fluid outlet (<NUM>) and a drain (<NUM>).