Patent Description:
The present invention relates generally to a filter backwash control system and process in a water treatment plant. More particularly, but not by way of limitation, embodiments of the present invention use filter media bed expansion and filter tank backwash turbidity to conserve water by reducing the amount of water utilized during the filter backwash process.

Surface water, such as lake, stream, canal or river water, or subterranean water, are generally treated in water treatment plants to prepare the water for use as drinking or potable water for human consumption or use, including coagulation, sedimentation, filtration and disinfection processes. This raw or pre-treated water often contains bacteria, pathogens, organic and inorganic substances that can cause a bad taste or odor, or is otherwise not safe for human consumption. For example, the water may contain organic substances from decaying vegetation, or chemicals from various agricultural or industrial applications, such as pesticides and herbicides. These water treatment plants utilize filtration systems to remove suspended solids from the water prior to it being delivered to the end consumer.

Many wastewater treatment plants include a final stage of wastewater treatment usually referred to as a tertiary surface water gravity filter system to prepare the wastewater before returning to the general environment including rivers, lakes, streams or the ocean or for human non-potable reuse purposes such as watering golf courses, lawns and public areas. This final treatment of the wastewater removes suspended solids from the water prior to it reaching the Wetwell, a finished wastewater storage area in the wastewater water plant, before ultimately being delivered to the environment.

These filtration or filter systems can be single, dual or multi-media filters that are designed and built in all types of physical configurations which allow water to flow thru the filter by gravity. The filter systems are designed so that the media in the filters catch sufficient suspended solids in the water as it flows thru the media to reduce the filter effluent (i.e. the water coming out of the filter) turbidity to a predetermined acceptable level (e.g., for human consumption or to be returned to the environment). Over time, the captured suspended solids in the filter's media starts to clog the filter reducing the performance and flow of water out of the filter. Once the filter's performance is reduced to a predetermined low level, the filter must be backwashed to clean them and return them to service for maximum performance. This phenomenon is measured in various ways including increasing filter effluent turbidity, increasing filter headloss, increasing filter level, and a predetermined time duration. If any of these events occur, the filter must be backwashed to return it to maximum performance.

The filters need to be backwashed periodically, sometimes as much as two (<NUM>) to three (<NUM>) times per week depending on water effluent quality conditions. During the backwash procedure, the treated water used to clean the filter is routed to a wastewater treatment system in the plant such as a clarifier, lagoon, pond and or pumped back to the head of the plant. Typically, this filter backwash wastewater is sent to the treatment plant's wastewater treatment system for processing, treatment and removal. The excess backwash water wasted can be substantial and worth a significant amount of money and reduced production to the treatment plant. Thus, optimizing a filter backwash system's performance can reduce the amount of filter backwash wastewater used during the backwash process thereby increasing plant water production and decreasing plant wastewater treatment while saving money.

<CIT> discloses applying different washwater velocities to fluidize different ranges of a filter medium layer. <CIT> discloses a water filter system comprising a control system, communication means, piping, actuators, sensors and valves. The control system utilizes a communication bus for controlling and monitoring water flow through the piping via control of the actuators and valves. <CIT> discloses a valve for diverting a flow of water to be passed in one direction or the reverse through a water rejuvenation bed.

While certain embodiments will be described in connection with the preferred illustrative embodiments shown herein, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives and modifications as may be included within the scope of the invention as defined by claims. In the drawing figures, which are not to scale, the same reference numerals are used throughout the description and in the drawing figures for components and elements having the same structure, purpose or function.

The present disclosure will now be described more fully hereinafter with reference to the accompanying figures and drawings, which form a part hereof, and which show, by way of illustration, specific example embodiments. Subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any example embodiments set forth herein; example embodiments are provided merely to be illustrative.

Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase "in one embodiment" as used herein does not necessarily refer to the same embodiment and the phrase "in another embodiment" as used herein does not necessarily refer to a different embodiment. It is intended, for example, that claimed subject matter include combinations of example embodiments in whole or in part.

For example, terms, such as "and", "or", or "and/or," as used herein may include a variety of meanings that may depend at least in part upon the context in which such terms are used. Typically, "or" if used to associate a list, such as A, B or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term "one or more" as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense.

<FIG> depicts a schematic diagram of a water treatment filter system <NUM> during the process of filtering water that includes a filter backwash process control system and method in a filter backwash process control system (more precisely: a process for backwashing a water treatment filter) in accordance with an embodiment of the present invention. The instrumentation, components, operation, and configuration of a filter and filter backwash system is described in detail below. While <FIG> depicts the filter system <NUM> and its associated instrumentation, and valves, <FIG> shows the various instrumentation, actuators and valves of the filter system <NUM> operatively in communication with a control system <NUM>, such as a DCS, PLC, SCADA, or wireless control system (e.g., wireless instrumentation and control devices that communicate in over a wireless network, including those that implement industry standards, such as the WirelessHART or HART <NUM> standard), or a combination of these types of control systems that are used to monitor and control the operation of water filter system, including a backwash process control system and process in accordance with an embodiment of the present invention. Further, communication and connection of the various instrumentation, actuators and valves with the control system, can also include a communication bus for controlling and monitoring the various instrumentation, actuators and valves within the water filter system, wherein the communication bus comprises an Actuator Sensor-Interface (AS-I) two-wire network in a loop and or star configuration coupling various instrumentation, actuators and valves to the filter control system, such as depicted in <FIG>. Further, the actuators that facilitate the movement of the valves from an open to a close position may be a vane-type pneumatic actuator, cylinder-type pneumatic actuator, hydraulic-type actuator, or electric-type actuator.

For example, in reference to <FIG>, the flow of water through the water filter system is monitored by instrumentation and controlled by valves and piping and is typically operated by allowing water to flow through the filter by gravity (non-pressurized) thru multimedia (e.g. anthracite, sand and gravel), then thru the filter bottom into a collection gullet and finally out of the filter through an effluent flow control valve into a water plant well, such as a clearwell or a wastewater plant wetwell. The process of treating water for use or reuse includes first flowing through an influent valve <NUM> prior to entry into a filter <NUM>. The filter <NUM> can include various media to eliminate certain undesirable elements from the pre-treated water. For instance, the filter <NUM> can be a multi-media <NUM> filter that can include, gravel <NUM>, sand <NUM> and anthracite <NUM> which operate to filter the pre-treated water as it flows thru the media <NUM>. Using control system <NUM>, INFLUENT valve <NUM> allows the flow of treated or settled water from the water source into the filter <NUM>. The level of water in the filter <NUM> can be ascertained by a level sensor <NUM>. The EFFLUENT flow control valve <NUM> controls the amount of filtered water that leaves filter <NUM> and
is measured by the effluent flow meter <NUM>. The effluent flow control valve <NUM> can be a modulating (i.e. percentage open) or a non-modulating (i.e. open/close) valve.

Level sensor <NUM> can include hydrostatic pressure devices, such as differential pressure transmitters or submersible pressure sensors that utilize piezoresistive sensing elements, ultrasonic/sonar level devices, radar level devices, ultrasonic level devices, capacitance level devices, vibronic level devices, and ball-float level devices. As described above, the filter <NUM> is a dual media filter that must be backwashed from time-to-time which requires level sensor <NUM> to monitor the level as the filter level is lowered and raised during the backwash and to monitor and assist in controlling the filter level while filter <NUM> is filtering water.

Effluent flow meter <NUM> can include any suitable flow meter that is capable of measuring the flow of water, including using venturi flow tubes with differential pressure transmitters, orifice plate with differential pressure transmitters, ultrasonic, turbine and magnetic flowmeters. As described above, the filter <NUM> is a dual media filter that filters water and from time-to-time must be backwashed which requires the effluent flow meter <NUM> to measure and control the filtered water flow out of filter <NUM> in conjunction with EFFLUENT flow control valve <NUM> and level sensor <NUM> to regulate this flow to maintain a constant water level on top of filter
<NUM>. During a backwash, EFFLUENT flow control valve <NUM> is closed after the filter level is lowered to a predetermined low level, remains closed throughout the remainder of the backwash and reopens when the filter backwash is complete and the filter effluent turbidity is at or below a specified low level such as <NUM> NTU.

In an embodiment of the present invention, a multiphase or interface level device that can measure both the media level (e.g., the level of the anthracite <NUM>) and the overall fluid level within the filter <NUM> is used. For example, multiphase measurement can be done with a radiometric level device, a guided wave radar and capacitance sensor, such as multi-electrode capacitance level sensors, combined in a single device. While it may be preferable to utilize a multiphase or interface level measurement device, embodiments of the present invention can also utilize separate level measurement devices, wherein one level device <NUM> provides a media level expansion measurement, and a separate level device <NUM> provides the overall water level in the filter, wherein level device <NUM> is capable of measuring an interface level that provides the level of the media below the overall filter <NUM> water level.

Turbidity is a parameter used to determine the quality of water exiting the filter <NUM> through the EFFLUENT flow control valve <NUM>. Typically, turbidity is measured by a nephelometer which uses light measurements thru water samples to measure the quantity of suspended solids in units referred to as Nephelometric Turbidity Units (NTU). For example, clean water has very low levels of suspended solids or low values of NTU while dirtier water has higher levels of NTU. The quality of potable or drinking water is generally determined by federal, state or community authorities. For example, acceptable desired operational turbidity values in filtered water exiting from the filter effluent are typically less than <NUM> NTU. An effluent turbidity analyzer <NUM> is used to determine the turbidity of the effluent filtered water. If the filtered water from the filter <NUM> is determined to be acceptable, for example, the filter effluent has a turbidity of less than
<NUM> NTU, a BACKWASH WASTE valve <NUM>, a FILTER TO WASTE valve <NUM>, a BACKWASH SUPPLY valve <NUM>, and a SURFACE SWEEP/AIR SCOUR valve <NUM>, are all closed to allow the filtered water to exit the system via an opened EFFLUENT flow control valve <NUM>.

As the filter <NUM> operates, over time, the captured suspended solids in the filter's media <NUM> starts to clog the filter <NUM> reducing the performance and effluent water flow out of the filter <NUM>. As the filter <NUM> becomes clogged or dirtier, the effluent turbidity can start to increase, and the filter <NUM> may begin to experience head loss or a loss of head, meaning that the pressure differential across the filter <NUM> is increased. A HEAD LOSS device <NUM>, such as a differential pressure transmitter can be used to determine the filter's loss of head.

Some water treatment facilities also utilize Filter Effluent Particle Counter Analyzers. Particle counter analyzers are used to measure the size and quantity of suspended solids in water and can be used to detect Cryptosporidium. Cryptosporidium is a microscopic parasite that causes the diarrheal disease cryptosporidiosis. If the filter effluent particle count begins to rise, this may indicate the need to backwash the filter.

The reduction in filter <NUM> performance can be measured in various ways including rising filter effluent turbidity, rising filter headloss, rising filter level and time. Should the turbidity of the filtered water or the pressure differential indicated on the head loss device reach unacceptable levels, or if there is a rise in the filter level, such as in varying level filters, more than likely, the filter <NUM> is no longer capable of removing the undesirable elements from the pre-treated water. Additionally, filter <NUM> performance tends to degrade overtime. Filter runtime is one of the most common reasons to backwash the filter <NUM>. State regulatory agencies typically recommend
and often mandate a maximum duration in hours that a filter <NUM> should run before it is backwashed. Once the filter's performance is reduced or in instances where it reaches a predetermined filter <NUM> maximum runtime, the filter <NUM> must be backwashed to clean it and return the filter <NUM> to optimum performance. The filter <NUM> is cleaned using a backwash water system <NUM> and mechanical surface sweeps or air scour systems <NUM>. The backwash water system <NUM> includes a BACKWASH SUPPLY valve <NUM>, BACKWASH FLOW CONTROL valve <NUM>, backwash flow meter <NUM>, and a backwash pump (not shown) or backwash holding tank (not shown). The air scour systems <NUM> include an air blower (not shown) and AIR WASH valve <NUM>. In systems that use mechanical surface sweeps, pressurized water is used to cause a mechanical arm to rotate to loosen the debris in the media <NUM> surface.

Media level sensor <NUM> can be a level device that is capable of measuring the level in a multiphase solution as described above in reference to filter level sensor <NUM>. For example, media level sensor <NUM> can be an ultrasonic sonar level device which must be immersed in water in order to measure the level of the media. When using a level device such as an ultrasonic level device, media level sensor <NUM> is installed in filter <NUM> with the bottom of the sensor at a height just below the top of the troughs <NUM> in order to ensure that media level sensor <NUM> is submerged at all times during a backwash. As described above, the filter <NUM> is a media filter, and in an embodiment of the present invention, a sonar level or capacitance level device is used in filter <NUM> that can measure both the media level while filtering water (e.g., the combined level of the anthracite <NUM>, sand <NUM>, and gravel <NUM>) and the increase in level of the media <NUM> (media expansion), which is the media level below the overall water level in the filter during a backwash procedure. From this level and change in level, media bed expansion can be calculated in inches, millimeters, or percent. Media bed expansion is defined as the change in media level from the settled media level (e.g., the combined level of the anthracite <NUM>, sand <NUM>, and gravel <NUM> while filter <NUM> is filtering water) and the amount that the media is fluidized, expanded or raised during a backwash procedure. Media expansion is caused by reversing water flow through the media from below it with the backwash water system <NUM> which is controlled by opening the BACKWASH SUPPLY valve <NUM>. The rate of backwash flow, which creates the media expansion, is measured by the backwash flowmeter <NUM> and controlled by the BACKWASH FLOW CONTROL valve <NUM>. Using control system <NUM>, during the backwash procedure and media bed expansion process the backwash water raises the level of the water in filter <NUM> to a level that the backwash water flows over and into filter troughs <NUM> (e.g., typically, one or more troughs are installed across a filter above the media at a certain height and spaced at even intervals to allow backwash procedures to be performed based on the specific design characteristic of a filter). Troughs <NUM> are long cylindrical tubes, open at the top and installed in opposite filter walls with openings through the filter walls at one or both ends of the trough <NUM> to allow water to enter or leave the filter. Water that needs to be filtered enters filter <NUM> through INFLUENT valve <NUM> on one end of the troughs <NUM> and then flows into the filter <NUM>. While filtering, the BACKWASH WASTE valve <NUM> is closed. During a backwash procedure, the INFLUENT valve <NUM> is closed and the BACKWASH WASTE valve <NUM> is open. This allows the backwash wastewater to leave filter <NUM> by overflowing the trough and draining out of the end of the troughs <NUM>, through the BACKWASH WASTE valve <NUM> to a wastewater treatment system.

Backwash water turbidity sensor <NUM> is a turbidity analyzer that measures the turbidity of the backwash water during a backwash procedure. The backwash water turbidity sensor <NUM> is typically installed in filter <NUM> with the bottom of the sensor at a height just below the top of the troughs <NUM> in order to ensure that the turbidity of the backwash water is measured at all times during a backwash. As described above, the filter is a media filter, and in an embodiment of the present invention, a backwash water turbidity device is used in filter <NUM> that can measure both the in-filter or settled turbidity of the water while filtering water (typically, <NUM> to <NUM> NTU) and the turbidity of the backwash waste water during a backwash procedure (typically, <NUM> to <NUM> NTU). Backwash water is caused by reversing water flow through the media from below it with backwash system water <NUM> and the duration of the backwash procedure is controlled by the length of time that the BACKWASH SUPPLY valve <NUM> is open. During the backwash procedure, the backwash water raises the level of the water in filter <NUM> to a level that the backwash water flows over and into filter troughs <NUM> allowing the backwash turbidity device <NUM> to measure the backwash waste water as it flows over and into the filter troughs <NUM>. During a backwash procedure, the INFLUENT valve <NUM> is closed and the BACKWASH WASTE valve <NUM> is open allowing the backwash wastewater to leave filter <NUM> by draining out of the end of the troughs <NUM>, through the BACKWASH WASTE valve <NUM> to a wastewater treatment system.

Filter systems are designed and built in all types of physical configurations but with two major hydraulic processes for water to flow thru them by gravity (non-pressurized). A majority of these systems fall into two categories-constant level filters and varying level filters. It should be noted that embodiments of the present invention can be used in all types of water filter systems. Although <FIG> depicts a single filter <NUM>, water treatment plants typically include multiple filters ranging from as few as two to over one hundred depending on the size of the water treatment plant, and embodiments of the invention described herein can be used in each of a water treatment plant's filters.

Constant level filter systems typically include three or more filters <NUM> and utilize a common influent channel or pipeline to allow the flow of treated or settled water from the water source to each of the filters <NUM>. Water from the influent channel or pipeline flows directly into each filter <NUM> thru open INFLUENT valves <NUM> above the media <NUM> and equalizes at the same level in all filters <NUM>. Water flows downward thru each filter <NUM> by gravity thru the media <NUM> and then thru filter underdrain or bottom equipment <NUM> into a collection gullet where it flows out of the filter <NUM> thru a modulating EFFLUENT FLOW CONTROL valve <NUM> prior to it being delivered to the end consumer or to the environment. Notwithstanding any minimal loss of fluid via evaporation, maintenance or testing performed on the filter <NUM> system during operation, in general, the total amount of water that goes into a filter <NUM> system thru the common influent channel or pipeline must come out of the filter <NUM> system through the sum of the individual modulating filter EFFLUENT FLOW CONTROL valves <NUM> which maintains a constant level in the filter <NUM> system. This constant level is accomplished by utilizing a modulating EFFLUENT FLOW CONTROL valve <NUM> on the effluent of each filter <NUM> in conjunction with an effluent flow meter <NUM> and filter level sensor <NUM>.

Filters <NUM> which have been backwashed recently have clean or substantially clean media <NUM> which allow water to flow through them at a much quicker rate than filters <NUM> which have dirty or partially dirty media <NUM>. The longer that a filter <NUM> runs, the more it collects suspended solids in its media <NUM> increasingly impeding water flow thru that filter <NUM>. Typically, in a water treatment plant with multiple filters <NUM>, each individual filter <NUM> will have a different flow rate proportional to the cleanliness of the media <NUM> in the filter <NUM>. The sum total of the effluent flows <NUM> out of the filters <NUM> shall be equal to the flow into the filter <NUM> system from the flow of treated or settled water from the water source.

Each filter <NUM> has its own level sensor <NUM> and modulating EFFLUENT FLOW CONTROL valve <NUM> which, the process control system <NUM> uses to maintain a relatively constant level in the filter <NUM> regardless of the effluent flow rate through that filter <NUM>. After a backwash, when a filter <NUM> with clean media <NUM> is placed back in service, the cleaned media <NUM> allows a maximum water flow rate through it which proportionately and slightly lowers the level of the overall filter <NUM> system. The process control system <NUM> utilizes each filter's level sensor <NUM> measurement to react to this very slight but declining level change and adjusts a filter's respective modulating EFFLUENT FLOW CONTROL valve <NUM> to close slightly in order to restrict water flow out of its filter <NUM> to compensate for the decreasing level change which then increases to maintain a constant level over the filter <NUM> system at all times. In one embodiment, the effluent flow meter <NUM> measurement and filter level device <NUM> measurement are used in combination to maintain a relatively constant level in the filter.

Water flow through a filter <NUM>'s media <NUM> is inversely proportional to the cleanliness of the media <NUM>. After a backwash, when a filter <NUM> has the cleanest media <NUM>, the EFFLUENT FLOW CONTROL valve <NUM> is open a minimum amount allowing a flow rate through filter <NUM> proportionate to the total number of filters <NUM> in the filter <NUM> system. As water flows through the media <NUM>, the media <NUM> begins to collect suspended solids slowly becoming dirty and impeding the flow of water through filter <NUM>. Over time, the increasingly dirty media <NUM> causes the EFFLUENT FLOW CONTROL valve <NUM> to slowly open to allow more water to flow through filter <NUM> to maintain the constant level across the filter <NUM> system. Often, immediately before filter <NUM> is due to be backwashed with the media <NUM> at its dirtiest, the EFFLUENT FLOW CONTROL valve <NUM> is open a maximum amount allowing a flow rate through filter <NUM> proportionate to the total number of filters <NUM> in the filter system <NUM>.

As the various filters become dirty over time, the water level slowly rises and the level sensors <NUM> compensate by slowly modulating the effluent control valves <NUM> of each filter to open or close more in order to maintain a constant level over the filters at all times. The longer a filter <NUM> runs before being backwashed the dirtier it becomes, reducing the flow of water thru it, and as a result, the respective effluent control valve <NUM> must increasingly open in order to maintain constant level. In a constant level filter system, you can determine how dirty a filter <NUM> is respective to other filters in the filter system by the percentage amount that its effluent control valve <NUM> is open compared to the other filters. The more open the effluent control valve <NUM> is, is an indication that the filter <NUM> is dirtier as compared to other filters. This can also be used to determine when a backwash of the filter <NUM> is needed.

Varying level filter systems typically include three or more filters <NUM> and utilize a common influent channel or pipeline to provide water to all of the filters <NUM> over individual weirs into each filter <NUM>. The weirs are physically adjusted and set to a specific but equal height to ensure that a proportionate and equal amount of water flows from the common influent channel or pipeline into each filter <NUM>. After the weir, the water flows through an INFLUENT valve <NUM> into filter <NUM>, allowing each filter to operate at a different level. In lieu of or in combination with weirs, varying level filter systems can also utilize modulating influent control valves <NUM> that can be used to regulate the effluent flow rate, including controlling the respective filters' influent modulating control valves to achieve substantially identical effluent flow rates across the filters. Similar to constant level filters water flows downward through the media <NUM> by gravity and then through filter underdrains or bottom equipment <NUM> into a collection gullet where it flows out of the filter <NUM> typically through a fully open/fully close non-modulating EFFLUENT FLOW CONTROL valve <NUM> prior to it being delivered to the end consumer or to the environment. However, modulated effluent control valves, such as those typically used in constant level filters can also be used. Further, varying level filter systems can also utilize modulating effluent control valves that can be also used to regulate the effluent flow rate, including controlling the respective filters' effluent modulating control valves to achieve substantially identical effluent flow rates across the filters.

In the case of varying level filters while filtering water, the open-close EFFLUENT FLOW CONTROL valves <NUM> are typically fully open at all times allowing each filter <NUM> to seek its own level based on a certain flow rate, the gravitational effect of water's weight and how dirty the filter's media <NUM> is. The cleaner the media <NUM> is at any flow rate, the lower the level in filter <NUM> will be. As the media <NUM> collects suspended solids over time, the water level in filter <NUM> will increase proportionate to the flow rate, the gravitational effect of water's weight and the dirtiness or resistance of the media <NUM>. When the water level in filter <NUM> has risen to a predetermined maximum height, the media <NUM> is considered dirty and it is time for filter <NUM> to perform a backwash. Clean filters that have been backwashed recently allow water to flow thru them at a much quicker rate than dirty or partially dirty filters. The longer that a filter <NUM> runs, the more it collects suspended solids in its multimedia causing it to become dirtier and impeding flow thru that filter. In a water treatment plant with multiple varying level filters, each filter <NUM> will typically run at the same flow rate but with different water levels in each filter <NUM> based on individual filter <NUM> runtimes, water height and degree of cleanliness.

Varying level filters are typically taller in height than constant level filters to allow the filter <NUM> level to increase over time proportionate to filter <NUM> flow rate and media <NUM> cleanliness. Typically, the influent water cascades into the filter and because the effluent control valve <NUM> in varying level filters is typically run in a fully open position, the filter level is a result of how quickly the water can flow thru the multimedia, which is based on the dirtiness of the filter.

After a backwash when a clean filter is placed back in service, the influent flow control valve <NUM> is opened and the water flows thru the media very quickly and is at its lowest level. As the media gets dirty, the level in the filter begins to increase due to resistance and dirt in the media. Because the effluent valve <NUM> is typically fully opened and therefore provides a constant effluent flow rate, the amount that the water rises is typically proportional to the dirtiness of the media and the gravitational effect of water's weight pushing thru the ever increasingly dirty media.

Like constant level filters, each filter <NUM> can include its own level sensor <NUM> that measures the level of the water in the respective filter <NUM>. In the case of varying level filter systems, level sensor <NUM> is used to measure the increasing water level in filter <NUM> as it filters water over time, but because the effluent control valve <NUM> in these filters is typically fully opened/fully closed, these level sensors <NUM> are typically used to measure the water level as an indicator of when a backwash may need to be initiated. Additionally, like constant level filter systems, when the filter water level reaches a dangerously high level (e.g., approaching filter overflow), the system can generate an alarm, and automatically close the filter INFLUENT control valve <NUM>. Level sensors <NUM> can also be used in combination with modulated influent control valves <NUM> or modulated effluent control valves <NUM>, or a combination of both to achieve substantially identical effluent flow rates across the filters.

In a typical varying level filter system that utilizes non-modulating influent or effluent control valves (<NUM>, <NUM> respectively), as the various filters become dirty over time, the water level in respective filters slowly rise and you can determine the dirtiness of a filter respective to other filters by looking at the height of water in each filter. The higher a filter's level the dirtier the filter is. The height of the filter's water can also be used to determine when a backwash of the filter is needed.

In one embodiment, the process control system <NUM> in both constant level and varying level filter systems, uses modulated influent and effluent control valves (<NUM>, <NUM> respectively), including in combination with the filter water level to control the overall runtime of a filter <NUM>, by reducing the time required to backwash a given filter <NUM>. For example, in instances of higher demand for water supply, controlling these devices can allow longer filter runtime, by for example, reducing the flow rate in a given filter, in order to maintain an acceptable turbidity reading or turbidity rate increase. Additionally, when a filter is out of service, for example due to maintenance, including the need for backwashing a filter, controlling the influent and effluent control valves (<NUM>, <NUM> respectively), the influent and effluent flow rates, and including using the filter level sensor <NUM> of the remaining online filters can be used to increase effluent flow rates to meet the demand due to a filter being out-of-service.

While <FIG> depicts the filter system <NUM> and its associated instrumentation, and valves, <FIG> shows the various instrumentation, actuators and valves of the filter system <NUM> operatively in communication with a control system <NUM>, such as a DCS, PLC, SCADA, or wireless control system (e.g., wireless instrumentation and control devices that communicate in over a wireless network, including those that implement industry standards, such as the WirelessHART or HART <NUM> standard), or a combination of these types of control systems that are used to monitor and control the operation of a water filter system, including a backwash process control system and process in accordance with an embodiment of the present invention. Further, communication and connection of the various instrumentation, actuators and valves with the control system, can also include a communication bus for controlling and monitoring the various instrumentation, actuators and valves within the water filter system, wherein the communication bus comprises an Actuator Sensor-Interface (AS-I) two-wire network <NUM> in a loop and or star configuration coupling various instrumentation, actuators and valves to the filter control system, such as depicted in <FIG>.

In one embodiment, the operation and control of the filter system <NUM>, including all of the valves, pumps and sensors (cumulatively, the "devices") can be controlled or monitored by a control subsystem <NUM>. The devices are generally coupled to the control panel <NUM> via a bus <NUM>. Additionally, the system can be controlled and monitored remotely, and filter system <NUM> data for one or a multitude of filter systems is collected, analyzed, and used for benchmarking purposes, as well as optimization and predicting operation of filters to generate and predict filter setpoints, measurements, and values. For example, and as shown in <FIG> and as discussed further below, there is data collection via a computer communication network of the filter operating parameters and determined setpoint data for a plant filter system, wherein using data analytics, artificial intelligence, machine learning and/or neural network methodologies to: predict the subject, a related, or an unrelated filter's performance and/or operational setpoints; generate benchmarking metrics for filter systems' operation and maintenance; and/or generate setpoints and anticipated measurement and filter operational values.

<FIG> shows an example of a deep neural network (NN) architecture <NUM> including a matrix of connected neuron processors. The matrix of neural processors is configured as a computation unit that operates as a two-dimensional systolic array. The two-dimensional systolic array includes multiple cells that are configured to identify probabilities for three categories of content. By way of example, the input neurons x<NUM> through x<NUM> are activated through input data and operate as sensors that perceive the input, and are for example in an embodiment of the invention, filter parameter data, such as measurement data that is received from filter instrumentation, and can include filter media level from level device <NUM>, filter tank turbidity measurements from backwash turbidity meter <NUM>, and filter backwash flow rate from filter backwash flowmeter <NUM>. The middle layers, sometimes referred to as the hidden layers, which include neural processor layers h<NUM> through h<NUM> and h<NUM> through h<NUM>, are activated through weighted connections and receive activation data from previous neural processors. For the sake of simplicity, two middle layers are shown although these layers can be multiples of what is shown and the number of layers depends upon the input and how "deep" of an accumulative learning process is required to obtain a reliable result. Some of the neural processors in the middle layers will influence the output by triggering events based upon one or more other events occurring in the middle layer or directly from input data. Depending upon the accuracy and comprehensiveness of the input data, the problem to be solved and how the neural processors are connected, obtaining an output z<NUM> and z<NUM>, for example optimum filter bed media expansion setpoint during the high-wash backwash procedure, and optimum filter backwash tubidity after completion of the high-wash backwash procedure, that reliable within a degree certain can require long causal chains of computational stages wherein each of the stages in the chain transforms the activation of the subsequent stages in a non-linear fashion. As shown in <FIG>, the deep neural network <NUM> is configured to analyze each of the vectors to generate probabilities to determine a final confidence score for the output z<NUM> and z<NUM> that reliable within a degree certain.

Further, in one embodiment, communication and control of the control subsystem <NUM> and the devices adhere to the Actuator Sensor-Interface (AS-I) standard. The AS-I bus <NUM> is comprised of two (<NUM>) wires, preferably fourteen (<NUM>) gauge wires, capable of carrying digital data and power to the various devices. The power to the bus <NUM> is provided by the control subsystems' power supplies PS1 and PS2. The AS-I standard specifies that the power supply generally provide a low voltage generally twenty-four (<NUM>) to thirty (<NUM>) volts over the bus <NUM>.

As shown in <FIG>, the control logic of the control subsystem <NUM> is a programmable logic controller (PLC) <NUM>. However, other control systems or control system components, such as SCADA, DCS and wireless control systems can be used in accordance with an embodiment of the invention. The controller <NUM> provides the necessary processors to transmit and receive data over the bus <NUM>. Should the PLC or other control system component be non-AS-I compliant, a gateway <NUM> provides the necessary interface for the control subsystem <NUM> to transmit and receive digital data and power over the bus <NUM>. A display <NUM> generally provides status information of the filter system <NUM>. In addition, a man machine interface <NUM> provides the necessary interface for a user to initiate various control and monitoring functions of the devices, such as initiating a backwash process. For security, the control subsystem <NUM> may include hardware (such as a key lock) or software (password) to prevent unauthorized personnel from using the system.

The AS-I standard generally specifies a master/slave bus configuration. The control subsystem (master) and the devices (slave) are designed to operate on an AS-I bus <NUM>, wherein the devices, such as valves and measurement instrumentation (sensors) are coupled to the bus for power and communication via an AS-I interface. For example, a device may be a valve, such as the INFLUENT valve <NUM>. The INFLUENT valve <NUM> includes a valve, an actuator and an AS-I interface <NUM>. The INFLUENT VALVE <NUM> is coupled to the AS-I bus <NUM> via AS-I interface <NUM>. In addition, the interface can include a switch and a disconnect switch offering a convenient method to remove, replace or repair a slave device while the remainder of the bus devices remain on line. Further the state of the valves can be ascertained by the AS-I interface. The AS-I valve interfaces may include positioning sensors to ascertain the state (e.g., the position of a disc of a butterfly type valve) of the valves. In addition, the AS-I interfaces can include processing capabilities to communicate digital data to and from the sensors and valves and provide power from the bus <NUM>. As shown in <FIG>, the actuators of valves <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> are coupled to the AS-I bus <NUM> via AS-I interfaces <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>, respectively. Similarly, measurement sensors <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, are coupled to he AS-I bus <NUM> via AS-I interfaces <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, respectively.

Referring to <FIG>, each AS-I Interface includes a processor (not shown) for sending and receiving data from the bus <NUM>. The AS-I interfaces are configured in a serial fashion on the bus <NUM> and each interface (i.e., each slave) has its own identification number. Furthermore, the AS-I interfaces also provide power from the bus <NUM> to energize/de-energize the solenoids of the actuators of the various valves. Consequently, should the filter system operate in the normal mode (e.g., pre-treated water flowing through the filter bed and out of the system), the control subsystem <NUM> would provide the necessary power and command over bus <NUM> to open the INFLUENT valve <NUM> via interface <NUM> and the EFFLUENT valve <NUM> via interface <NUM>, while closing the DRAIN VALVE <NUM> via interface <NUM>, the BACKWASH valve <NUM> via interface <NUM>, the AIRWASH valve <NUM> via interface <NUM> and the FILTER TO WASTE valve <NUM> via interface <NUM>. In addition, should it be necessary to enter a backwash process, the control subsystem <NUM> would provide the necessary power and command to the appropriate valves to perform such process (as previously described). Thus, operating parameters of the water treatment system may be monitored by the control subsystem <NUM> via the AS-I bus <NUM>.

Although the topology of the various AS-I interfaces and devices can be in a number of configurations, such as a linear configuration or a tree configuration, the preferred topology is a loop configuration (as shown in <FIG>). The loop configuration provides for better fault tolerance. For example, should the bus <NUM> experience a break <NUM>, power and data and still be carried over the bus <NUM> in either direction A or B, away from the break. Furthermore, a test sequence may be initiated by the control subsystem <NUM> to test the various devices. Upon receipt of a test command, the processor within the AS-I interfaces performs a self-test to determine the status of the device. The results of the self-test are transmitted to the control subsystem <NUM> via the bus <NUM>.

Next, the control subsystem <NUM> is capable of interfacing to a Supervisory Control and Data Acquisition (SCADA) system or other control subsystems via a communication link <NUM> or a wireless system. In one embodiment, the communication link <NUM> is an Institute of Electrical and Electronic Engineer (IEEE) standard <NUM> bus (ETHERNET). Typically, a water treatment plant includes a number of water filter systems. Therefore, from a single location, the SCADA system can monitor and control the various water filter systems from one location via the communication link <NUM>.

Also, status from the various devices may be monitored by a user or a software routine for further action. For example, the water filter system may be damaged should one of the valves in the system malfunction. For instance, should valve <NUM> not close upon a command to close, the valve's AS-I interface <NUM> could sense the malfunction and trigger an alarm. Since each AS-I device has its own identification device number, the AS-I interface <NUM> would transmit the alarm status to the control subsystem <NUM> via the bus <NUM>, whereby the control subsystem <NUM> would identify the malfunctioned valve.

In addition, the devices and control subsystem of the present invention may be prepackaged in a kit form. The devices and control subsystem may be pre-tested for installation. Consequently, the kit can be used to retrofit existing and new water filter systems.

The need to perform a filter backwash can be determined by a variety of measured, control system <NUM> generated, or external system generated filter parameters, including a predetermined high effluent turbidity that is measured by effluent turbidity meter <NUM>, high head loss, which is measured by pressure differential transmitter <NUM>, maximum filter runtime, high water level in the filter <NUM> (e.g., in varying level filters), percentage open of the effluent flow control valve <NUM>, effluent flow rate, influent flow rate, filter effluent particle count, anticipated values for these parameters that is generated through data analytics, artificial intelligence, machine learning and/or neural network methodologies, or a combination of these values. These value setpoints can be stored in a database, in processor memory, integrated into the control system <NUM>, or received via external or remote inputs. The system receives inputs from the various instrument devices, or by internal system programs that analyze, manipulate, or transform the instrument value data into new system data that is a system process value. For example, one setpoint might be an effluent turbidity setpoint of <NUM> NTU. As the system <NUM> receives effluent turbidity measurement data from effluent turbidity meter <NUM>, the system <NUM> compares this to the stored or in some cases generated effluent turbidity setpoint, and if the effluent turbidity setpoint is reached, the control system <NUM> signals initiation of the backwash procedure, as depicted in the flowchart shown in <FIG> at step <NUM>. Similarly, if the measured or system generated values of one of the preceding filter parameters exceeds the programmed setpoint, the system <NUM> initiates the backwash procedure <NUM>.

At the beginning of a backwash procedure, using control system <NUM>, the level of the water in the filter <NUM> is lowered to a predetermined or system <NUM> generated low-level setpoint above the media <NUM>, which is typically between four (<NUM>) to six (<NUM>) inches (i.e. <NUM>,<NUM> to <NUM>,<NUM> centimeters) above the media <NUM>, by closing INFLUENT valve <NUM> while the EFFLUENT FLOW CONTROL valve <NUM> is still opened as shown in the flowchart in <FIG> at step <NUM>. The backwash low-level setpoint can be generated using data analytics, artificial intelligence, machine learning and/or neural network methodologies, or a combination of these values to: predict the subject, a related, or an unrelated filter's performance and/or operational setpoints; and/or generate benchmarking metrics for filter systems' operation and maintenance. For example, the optimum low-level backwash setpoint can vary based on the current conditions of the filter <NUM> and operational parameters of the filter <NUM> since the most recent backwash procedure was performed. For example, it is possible that at the time of backwash, the filter media <NUM> bed is dirtier than normal, and lowering the filter level too much, for example <NUM>" above the media <NUM>, might remove too much water such that the surface sweeps or air scours cannot operate effectively, creating a more viscous sludge in the filter <NUM>, that could result in under-fluidization of the media <NUM> in subsequent low and high wash steps <NUM>, <NUM> (<FIG>). For example, the influent water supply might have a higher than normal NTU value of <NUM>, and/or the filter has been running at maximum capacity or designed production rate, causing a dirtier filter bed. In one embodiment, the system determines and anticipates the recommended low-level backwash setpoint based on these and/other filter parameters using historical filter data, including data analytics, artificial intelligence, machine learning and/or neural network methodologies, or a combination of these processes.

In one embodiment, during step <NUM>, level sensor <NUM> measures the decreasing water level in filter <NUM> until it reaches a predetermined or system <NUM> generated level setpoint above media <NUM>, which then closes EFFLUENT FLOW CONTROL valve <NUM>. Once control system <NUM> confirms or receives an input that EFFLUENT FLOW CONTROL valve <NUM> is closed, using control system <NUM> the BACKWASH WASTE valve <NUM> is fully opened. The SURFACE WASH or AIR WASH valve <NUM>, the FILTER TO WASTE valve <NUM> and the BACKWASH SUPPLY valve <NUM> remain in a closed position, and in one embodiment control system <NUM> confirms these valve positions, and provides an alarm if the valves are not in a correct state at the stage of the backwash procedure. The level drop can be detected by the level sensor <NUM>. Using control system <NUM> after the water level is dropped to a predetermined or system <NUM> generated acceptable level (e.g., as detected for example by the level sensors <NUM> or <NUM>), the DRAIN valve <NUM> is closed. The INFLUENT valve <NUM>, the EFFLUENT valve <NUM>, the BACKWASH valve <NUM> and the FILTER TO WASTE valve <NUM> remain closed, and in one embodiment control system <NUM> confirms these valve positions, and provides an alarm if the valves are not in a correct state at the stage of the backwash procedure.

Referring to step <NUM> in the flowchart in <FIG>, in older filter systems, multiple mechanical rotating surface sweeps, depending on the surface area size of a filter <NUM>, installed in the anthracite media <NUM> and driven by distribution system water pressure are used to assist the low-wash flowrate backwash water at the beginning of a backwash procedure to help break up the compacted and dirty media <NUM> and assist in fluidizing the media <NUM>. Surface sweeps are mechanical arms that rotate (generally slowly) by control system <NUM> opening the SURFACE WASH valve <NUM>' and forcing pressurized water through orifices located on the back of the sweep arms to force them to rotate just beneath the surface of the media <NUM>. Fluidized media is defined as applying a reverse flow of water through settled media <NUM> to elevate, mix and ultimately wash suspended solids from the media <NUM> at predetermined flow rates and predetermined media bed expansion. Media bed expansion is defined as the difference in level in inches, millimeters, any suitable basis for measurement, or percent between the settled media level while filtering water and the expanded media level while backwashing filter <NUM>. For example, typical media <NUM> in a filter <NUM> can be a lower level of <NUM> inches (i.e. <NUM>,<NUM> centimeters) of sand <NUM> and an upper level of <NUM> inches (i.e. <NUM>,<NUM> centimeters) of anthracite <NUM>. Hence the total media <NUM> depth or level is <NUM> inches while filtering. While backwashing with a sufficient reverse flow of water from under the media <NUM>, the media will expand or fluidize by as much as <NUM>% or more (<NUM> inches (i.e. <NUM>,<NUM> centimeters or more) to an overall fluidized level of <NUM> inches (i.e. <NUM>,<NUM> centimeters) or more. ) Similar to the air blower, to control the speed of rotation of the mechanical sweeps, control system <NUM> can control a variable frequency drive that is operatively coupled to surface wash supply pump <NUM>' or can control a surface wash supply control valve <NUM>'.

Referring to step <NUM> in the flowchart in <FIG>, in newer filter systems, compressed air from a blower system <NUM> is used to assist low-wash flowrate backwash water at the beginning of the backwash procedure to help break up the compacted and dirty media <NUM> and assist in fluidizing the media <NUM>. Air washes and air bubbles from them have been determined to be more effective than older surface sweep systems as they cover the entire surface area of filter <NUM> and more effectively fluidize the media <NUM> during the initial low-wash procedure. Using control system <NUM>, compressed air is supplied by a blower system <NUM> (that includes a blower <NUM> (<FIG>) and air wash valve <NUM>) through a header to filter <NUM> by opening AIR WASH valve <NUM> during the initial low-wash flowrate step of the backwash procedure. Air wash valve <NUM> can be an open/close valve or a modulating control valve that opens or closes in increments, based on the control system <NUM> output values to the air wash valve <NUM> actuator to control the air wash flow rate. Typically, the optimal air flow rate for a filter <NUM> is predetermined by using the size of the blower system, physical hydraulic air header system and depth of media <NUM>. Typically during an air wash procedure, control system <NUM> runs blower system <NUM> at full capacity to produce the required air wash flow rate based on the physical characteristics of filter <NUM> and the media <NUM>. However, in another embodiment using control system <NUM>, a variable frequency drive can be used to control the air blower <NUM> in order to control the air flow rate, which can be measured by an air flow device, such as an orifice with a differential pressure transmitter. Although not shown in <FIG>, a VFD can also receive multiple inputs via the two-wire AS-I bus or direct/indirect wiring from a control panel to the VFD. Control system <NUM> can also control the air flow rate by sending outputs to control both the air blower <NUM> (e.g., via VFD (not shown)) and air wash valve <NUM>.

In one embodiment, as shown in <FIG> at step <NUM>, the air wash or surface wash is performed before backwash water enters the filter <NUM>. Using control system <NUM>, the air wash system <NUM> utilizes the remaining low level water in the filter <NUM> after the filter has been drained to a predetermined low level to help fluidize the media bed <NUM> and breakup the compacted and dirty media <NUM> before proceeding to the next step <NUM> (low-wash backwash procedure) of the backwash procedure as shown in <FIG>.

After a predetermined period of time for the surface wash or air wash procedure to elapse, or in one embodiment, once the media is fluidized to an optimal fluidization, optimum breakup of the filter debris or backwash turbidity, control system <NUM> initiates the initial backwash low-wash step <NUM> as shown in the <FIG> flowchart. At the beginning of the backwash low- wash step <NUM>, control system <NUM> controls the backwash flow rate at a low flow by monitoring the flow using the backwash supply flow meter <NUM> and controlling backwash supply pump <NUM> or backwash control valve <NUM>. In another embodiment, control system <NUM> controls the backwash low-wash flow using the filter level or rise rate of the filter level. In another embodiment, control system <NUM> controls the low-wash backwash flow rate by monitoring the fluidization of media bed <NUM>, filter level, or filter tank turbidity using a filter backwash turbidity meter <NUM> installed at or below the filter troughs <NUM>. Still in another embodiment, control system <NUM> controls the low- wash backwash flow rate by monitoring the filter tank's turbidity increase or rate of increase and comparing that to a backwash flow rate, total flow, or flow over elapsed time.

The flow of backwash water up through the media <NUM> causing expansion of the media is called fluidization of the media bed <NUM>. Because the backwash process cleans the filter to remove the influent water debris and particles that have settled in the media <NUM>, the water becomes very muddy, increasing the turbidity in the filter. Although this is a low backwash flow, there is still the potential for over-fluidization of the filter media <NUM>, meaning that there is too much backwash fluid added causing the media <NUM> to spill over the troughs <NUM> with the backwash water into the drain. For example, because the trigger to initiate a filter backwash is typically based on State regulatory agencies mandated filter runtime limits, it is possible that at the time of backwash, mandated or otherwise, the filter media <NUM> bed is not sufficiently dirty to necessitate higher low-wash flow rates, which if used, could result in over-fluidization of the filter media <NUM>. For example, if the influent water supply has a low NTU value of <NUM>, and/or the filter has been running below its capacity or designed average production rate, and/or the effluent turbidity, and/or the filter <NUM> level has been low (e.g. in varying level filters) the filter <NUM> may not be sufficiently dirty to perform backwash at preprogramed low and high wash rates because of the potential for over-fluidization.

In one embodiment, during the initial low backwash process as depicted in <FIG> at step <NUM>, a predetermined low backwash media expansion setpoint is used, and the networked computer system monitors the media expansion and controls the media expansion in order to maintain the desired low backwash media expansion setpoint by controlling the backwash low flow that is flowing up through the media <NUM>, such as using BACKWASH FLOW CONTROL valve <NUM>. In another embodiment, the system <NUM> determines the optimum initial low backwash media expansion setpoint or initial low backwash low flow rate and initial low backwash total run time or initial low backwash total flow using filter system operating parameters since the last backwash of: an average or mean influent NTU, effluent NTU, filter box NTU as measured by backwash filter backwash turbidity meter <NUM>, filter <NUM> level, filter effluent flow rate or filter <NUM> differential pressure, filter <NUM> runtime or filter effluent production; or any combination of these filter system operating parameters. In yet another embodiment, there is data collection via a computer communication network of these filter operating parameters and determined setpoint data for a plant filter system, wherein using data analytics, artificial intelligence, machine learning and/or neural network methodologies to: predict the subject, a related, or an unrelated filter's performance and/or operational setpoints; and/or generate benchmarking metrics for filter systems' operation and maintenance.

In another embodiment, during the initial low backwash process, the system monitors the media expansion and controls the media expansion using a predetermined low flow rate in order to maintain the media expansion by controlling the backwash low flow that is flowing up through the media <NUM>. As backwash water is added the media bed experiences fluidization. Once the initial low backwash process has completed the system initiates the backwash high flow rate or high-wash backwash procedure as shown in <FIG> at step <NUM>.

Referring to the flow chart in <FIG>, in another embodiment, a low flow rate of backwash supply water is provided simultaneously with the air wash to help fluidize the media bed <NUM> and breakup the compacted and dirty media <NUM> before proceeding to the next step of the backwash procedure as shown in <FIG> at steps <NUM>' and <NUM>'. Here, while air is being provided to the media bed <NUM> to break up the dirty media, backwash water is provided to the filter using a backwash pump, opening BACKWASH valve <NUM> or backwash control valve <NUM> and monitoring the backwash flow using backwash flow meter <NUM>. And when backwash water is being supplied at the same time as the air scour, the control system <NUM> can also control the backwash flow by varying the speed of the backwash pump <NUM> (<FIG>) using a VFD and modulating the open- closed percentage of the backwash control valve <NUM>. In another aspect of this embodiment, filter media bed expansion is monitored and controlled by control system <NUM> based on a predetermined optimal air or surface wash flow rate and low flow rate backwash, wherein control system <NUM> controls the air or surface wash flow rate and low flow backwash flow rate to control the media fluid bed expansion or rate of media bed expansion. The flow of backwash water up through the media <NUM> causing expansion of the media is called fluidization of the media bed <NUM>.

In one embodiment, at the beginning of the initial backwash low-wash step <NUM>' shown in <FIG>, the SURFACE WASH valve <NUM> or the AIR WASH valve <NUM> is fully open and the INFLUENT valve <NUM>, EFFLUENT FLOW CONTROL valve <NUM> and the FILTER TO WASTE valve <NUM> remain fully closed, and the BACKWASH WASTE valve <NUM> remains opened, and in one embodiment control system <NUM> confirms these valve positions, and provides an alarm or stops the backwash procedure if the valves are not in a correct state at the stage of the backwash procedure. Using control system <NUM>, the backwash water system <NUM> is turned on, BACKWASH SUPPLY valve <NUM> is opened allowing potable backwash water from the clearwell (i.e., typically, a large concrete basin that stores treated water from the filters <NUM> before being pumped into the distribution system for consumers use) or directly from the consumer distribution system to enter filter <NUM> through the backwash flowmeter <NUM> and the modulating BACKWASH FLOW CONTROL valve <NUM>. In one embodiment control system <NUM> confirms these valve positions, and provides an alarm or stops the backwash procedure if the valves are not in a correct state at the stage of the backwash procedure. The initial low-wash backwash step is used to slowly refill the filter <NUM> while assisting the surface sweeps or air wash systems in breaking up and fluidizing the media <NUM>. Once the desired fluidization is reached, which as discussed above in reference to <FIG> and step <NUM>, can be determined or generated using various filter parameters and predictive parameters using data analytics, artificial intelligence, machine learning and/or neural network methodologies to: predict the subject, a related, or an unrelated filter's performance and/or operational setpoints; and/or generate benchmarking metrics for filter systems' operation and maintenance, control system <NUM> terminates the initial backwash low-wash <NUM>' and surface wash or airwash <NUM>' procedures as shown in <FIG> and initiates the backwash high-wash procedure as shown in <FIG> and <FIG> at step <NUM>.

In another embodiment, the ending of steps <NUM>' and <NUM>' in <FIG>, can also be achieved by filter level sensor <NUM> providing a measurement to control system <NUM> that is a predetermined level value (e.g., that the filter water level has risen to a level where the water can flow over the troughs <NUM> and out of filter <NUM>), and then the system <NUM> initiates the high-wash backwash procedure as shown in <FIG> at step <NUM>.

A variety of backwash water supply systems can be utilized. For example, Lead Lag Dual Variable Speed Pump Systems utilize two pumps running at variable speeds to create a low- wash flow rate and a high-wash flow rate. One pump is used for the low-wash flow rate and both pumps are used for the high-wash flow rate. The pumps are started based on which one is assigned the lead designation and the other one a lag designation. In these systems, a modulating flow control valve <NUM> is not typically used, and instead the backwash flow to a given filter in a multi-filter configuration water treatment system is controlled by BACKWASH valve <NUM>. In single pump systems, a common backwash flow control valve <NUM> and common Backwash Flowmeter <NUM>. This system utilizes one pump to provide backwash supply water from the clearwell. The water is pumped thru a common Backwash Flowmeter <NUM> and common Backwash flow control valve <NUM> which controls the backwash flow rate for both low and high washes for all filters.

Backwash holding tank systems use an elevated Backwash Holding Tank installed high enough above the filters to allow gravity flow from the tank to provide adequate low and high wash flow rates without the benefit of a pump. Water from the clearwell is pumped into the holding tank by one or more pumps and controlled by a level system in the tank. The level system is responsible to maintain a sufficient level in the holding tank at all times for at least two or more backwashes. Backwash water from the holding tank is provided to the Filter Backwash Supply flow control valve <NUM> thru a common Backwash supply line and backwash pump <NUM>.

In one embodiment of the present invention, the backwash high-wash procedure <NUM> (<FIG> or <FIG>) in the control system <NUM> includes a pre-determined or generated high-wash flow rate control system and/or a pre-determined or generated timer control. In a further aspect of an embodiment of the present invention, the control system <NUM> determines a backwash high-wash flow rate or backwash high-wash duration based on the filter level or rise rate of the filter level, the fluidization of media bed <NUM>, filter tank turbidity using filter backwash turbidity meter <NUM>, the filter tank's turbidity increase or rate of increase, the low-backwash flow rate, low-backwash total flow, or low-backwash flow over elapsed time, or any combination of these parameters. Control system <NUM> includes the backwash high-wash flow control system, which can include a backwash flowmeter <NUM>, modulating BACKWASH FLOW CONTROL valve <NUM>, backwash flow rate set point, backwash total flow, high-wash backwash duration timer, a media expansion level setpoint, a media level setpoint, or a media level expansion rate of change setpoint. In some cases a minimum high-wash backwash duration is set by a consultant or state regulatory agency. As discussed in this paragraph, these filter parameters and setpoints can be a variety of measured, control system <NUM> generated, or external system generated filter values, and anticipated values for these parameters can be generated through data analytics, artificial intelligence, machine learning and/or neural network methodologies, or a combination of these procedures. These value setpoints can be stored in a database, in processor memory, integrated into the control system <NUM>, or received via external or remote inputs. The system receives inputs from the various instrument devices, or by internal system programs that analyze, manipulate, or transform the instrument value data into new system data that is a system process value.

Referring to <FIG>, as the backwash water flows upward through the media <NUM>, the water level begins to rise and flow over the filter troughs <NUM>, out of the filter <NUM> through filter drain <NUM> into a wastewater treatment system. In an embodiment of the present invention, using media level sensor <NUM>, which is installed in filter <NUM> to allow control system <NUM> to monitor media bed expansion <NUM>, control system <NUM> controls the backwash flow rate using backwash supply control valve <NUM>, in order to ensure that the media bed <NUM> is fluidized or expanded sufficiently to a pre-determined level to efficiently clean the media <NUM>, while not over expanding or over fluidizing the media <NUM> and washing media <NUM> over the troughs <NUM> causing the quantity of media <NUM> in the filter <NUM> to diminish to insufficient levels over time. In one embodiment, control system <NUM> controls media bed expansion <NUM> by predetermined or generated values or setpoints for a high-wash backwash flow setpoint, a rate of media bed expansion, or the media bed expansion value, or a combination of these parameters. In this embodiment, control system <NUM> adjust the output to the backwash supply control valve <NUM> to adjust the high-wash backwash flow rate in order to maintain a specific media bed expansion <NUM> using the foregoing parameters. Because colder water is denser than warmer water and can therefore cause increased media bed expansion <NUM> for a given flow rate, in a further embodiment of the present invention, control system <NUM> automatically adjusts the high-wash backwash flow rate to achieve and maintain a specific media bed expansion <NUM> set point that eliminates any effect of actual water temperature.

In an embodiment of the present invention, backwash water turbidity sensor <NUM> is installed in the filter box of filter <NUM> to monitor the filter turbidity and using control system <NUM>, during the high-wash backwash procedure <NUM> control the termination of the high-wash backwash procedure to ensure that the media <NUM> is washed sufficiently to a pre-determined backwash turbidity value, typically between <NUM> and <NUM> NTU, and not over washed, which results in not only hundreds of thousands of wasted water, but also results in removing necessary seasoning (turbidity) in the media <NUM> for an efficient return to service and operation of filter <NUM>. The backwash water turbidity sensor <NUM> also measures settled water turbidity while filter <NUM> is filtering water. In one embodiment, control system <NUM> terminates the high-wash backwash procedure <NUM>, when turbidity sensor <NUM> provides a turbidity value equal to a predetermined or generated setpoint in NTUs that is typically between <NUM> and <NUM> NTU. In another embodiment, the control system includes controls that terminate the high-wash backwash procedure <NUM> by a duration set point if the backwash turbidity sensor <NUM> fails for any reason, and a longer than anticipated high-wash backwash procedure has elapsed. In this embodiment if the control system <NUM> terminates the high-wash backwash procedure by the duration set point control, it indicates that there was likely a backwash turbidity sensor <NUM> failure. In a further aspect, an alarm is triggered through the control system to trigger inspection of the system.

In another embodiment of the present invention, while maintaining a desired media level expansion <NUM> setpoint, control system <NUM> terminates the high-wash backwash procedure <NUM> once the filter backwash turbidity, read by turbidity meter <NUM>, reaches a predetermined or generated setpoint that is designed to minimize the high-wash backwash procedure to ensure that the media <NUM> is backwashed sufficiently to a pre-determined backwash turbidity value and not over washed below that value which removes necessary seasoning (turbidity) in the media <NUM> for efficient return to service and operation of filter <NUM>. During this high-wash backwash process <NUM>, the turbidity of the water spikes extremely high due to a phenomenon called a mudboil. This turbidity spike is extremely high and may be so high that it exceeds the value that is able to be read by turbidimeter <NUM>. However, once the tubdidity starts to come down from the increased spike to a predetermined value (e.g., <NUM> to <NUM> NTUs, or any other value that has determined to be appropriate for seasoning of the filter media <NUM> prior to return to service), which can include a delta value from a peak turbidity to calculated change, and can include a specific value that is based on the influent water and a the control system <NUM> determining the turbidity value, a specific value determined by historical performance of the filter, or any specific value provided by the control system <NUM>, the high-wash backwash procedure is terminated.

Similarly as discussed above in reference to the initial low wash backwash procedure, it is possible that at the time of the high-backwash, the filter media <NUM> bed is not sufficiently dirty to necessitate higher high-wash flow rates, which if used, could result in over-fluidization of the filter media <NUM> and loss of filter media <NUM>. Hence, the filter parameters and setpoints for the high-backwash procedure <NUM> as shown in <FIG> and <FIG>, including the high wash filter backwash turbidity setpoint, can be a variety of measured, control system <NUM> generated, or external system generated filter values, and anticipated values for these parameters can be generated through data analytics, artificial intelligence, machine learning and/or neural network methodologies, or a combination of these procedures. These value setpoints can be stored in a database, in processor memory, integrated into the control system <NUM>, or received via external or remote inputs. The system receives inputs from the various instrument devices, or by internal system programs that analyze, manipulate, or transform the instrument value data into new system data that is a system process value.

After the high-wash backwash procedure <NUM> has been completed, control system <NUM> initiates a second low-wash backwash procedure step <NUM> to slowly resettle and stratify the media <NUM> in filter <NUM> with the anthracite <NUM> on top of the sand <NUM>. In one embodiment, during this step, the SURFACE WASH valve <NUM> or the AIR WASH valve <NUM> remain fully closed, the INFLUENT valve <NUM>, EFFLUENT FLOW CONTROL valve <NUM> and the FILTER TO WASTE
valve <NUM> remain fully closed and the BACKWASH WASTE valve <NUM> remains opened. The control system <NUM> controls the second low-wash backwash flow by monitoring the backwash flow meter <NUM> measurement or controlling the backwash supply pump <NUM> using a VFD. Control system <NUM> uses a predetermined or generated second low-wash backwash flow rate, including a second low-wash backwash flow rate that is designed to reduce the filter media expansion to an acceptable level that represents the resettling of the media <NUM>. In one embodiment, control system <NUM> terminates the second low-wash backwash after a predetermined or generated elapsed time, a second low-wash backwash total flow has been achieved, or a predetermined or generated acceptable reduced media expansion, or a combination of these parameters. In one embodiment, control system <NUM> terminates the second low-wash backwash based on the media level as determined by level device <NUM>, as an indicator of the filter media settling. For example, as discussed above, level device <NUM> can be a multi-electrode capacitance level sensor <NUM> that is capable of measuring an interface level that provides the level of the media below the overall filter <NUM> water level. Once control system <NUM> terminates the second low-wash backwash procedure <NUM>, control system <NUM> proceeds to return filter <NUM> to service by initiating the filter-to-waste procedure step <NUM>.

Once the second low-wash backwash procedure <NUM> is complete, control system <NUM> initiates the filter-to-waste step <NUM>. In one embodiment, during the filter to waste procedure step <NUM>, the BACKWASH SUPPLY valve <NUM> is fully closed, the backwash water system is turned off and the BACKWASH WASTE valve <NUM> is fully closed, the SURFACE WASH <NUM>' or AIR SCOUR valve <NUM>, and the EFFLUENT FLOW CONTROL valve <NUM> remain fully closed. The INFLUENT valve <NUM> is fully opened, then the FILTER TO WASTE valve <NUM> is fully opened to
allow the initial return-to-service filtered water to exit the filter to a wastewater treatment system until such time as the effluent turbidity of this water, which is measured by the effluent turbidity meter <NUM>, reaches a pre-determined or generated low turbidity value, usually less than <NUM> NTU acceptable for human consumption or use. In one embodiment, once this effluent turbidity value has been reached, control system <NUM> terminates the filter-to-waste step <NUM> by closing FILTER TO WASTE valve <NUM>.

In a further embodiment, once the system <NUM> terminates the filter-to-waste step <NUM>, the system initiates the filter return to service step <NUM> as shown in <FIG> and <FIG>, by opening modulating EFFLUENT FLOW CONTROL valve <NUM> allowing filtered water to go to the clearwell and to consumers for consumption anduse.

Similarly as discussed above in reference to the initial low wash backwash procedure <NUM>, and high-wash backwash procedures <NUM>, for the second low-wash backwash procedure <NUM>, filter to waste procedure <NUM>, and filter return to service procedure <NUM>, the filter parameters and setpoints for these procedures <NUM>, <NUM> and <NUM>, can be a variety of measured, control system <NUM> generated, or external system generated filter values, and anticipated values for these parameters can be generated through data analytics, artificial intelligence, machine learning and/or neural network methodologies, or a combination of these procedures. These value setpoints can be stored in a database, in processor memory, integrated into the control system <NUM>, or received via external or remote inputs. The system receives inputs from the various instrument devices, or by internal system programs that analyze, manipulate, or transform the instrument value data into new system data that is a system process value.

In another aspect of an embodiment of the present invention, the control system <NUM> generates output signals to control the various flow control valves and VFDs, using proportional-integral-derivative (PID), proportional, integral or derivative controllers. In another aspect of an embodiment of the present invention, the control system <NUM> generates output signals that are discrete on/off for valve actuators and pumps and blowers, and also generates output signals that are variable to control valve actuators and VFDs to pumps andblowers.

The before and after results of an example of a Georgia plant that has implemented certain embodiments of the invention is depicted in <FIG>. <FIG> shows the operation before implementation of certain embodiments of the invention. The green line <NUM> depicts the filter backwash turbidity before backwash. Orange line <NUM> depicts the fluid media level before the backwash. <NUM> depicts the filter backwash turbidity spike during initiation of the high-wash. <NUM> depicts the media expansion during high wash. <NUM> depicts the turbidity drop during the high wash. And <NUM> depicts the <NUM> minutes of additional time of backwashing, that has been eliminated by certain embodiments of the present invention.

<FIG> shows the operation of the Georgia plant after the implementation of certain embodiments of the invention. The green line <NUM> depicts the filter backwash turbidity before backwash. Orange line <NUM> depicts the fluid media level before the backwash. <NUM> depicts the filter backwash turbidity spike during initiation of the high-wash. <NUM> depicts the media expansion during high wash of about <NUM>%. <NUM> depicts the turbidity drop during the high wash down to around <NUM> NTU. And <NUM> depicts the <NUM> minutes of backwashing time, and <NUM> minutes of backwashing time eliminated by certain embodiments of the present invention.

In the Georgia plant, implementation of certain embodiments of the invention resulted in over $<NUM>,<NUM> in annual savings to the plant, the elimination of <NUM>,<NUM>,<NUM> million of gallons (ca. <NUM> cubic meters) of backwash water wasted ever year, and the elimination of a lagoon holding area for excess backwash waste water before reduced time for the high wash saved. Additionally, the effluent turbidity spike and filter to waste after filter backwash and placing filter back in service was virtually eliminated using certain embodiments of the invention.

Claim 1:
A water treatment filter backwash process control system, comprising: a control system (<NUM>) that is configured to receive filter backwash turbidity data from a backwash control turbidity sensor (<NUM>); and
wherein the control system further being configured to receive filter media level data from a filter media level sensor (<NUM>);
the control system (<NUM>) having a filter media level set point, wherein the filter media level set point corresponds to a desired filter media bed expansion;
the control system (<NUM>) having a filter backwash turbidity set point,
wherein the control system (<NUM>) is configured to control the filter backwash process while monitoring the filter backwash turbidity and the filter media level, by sending one or more variable output signals that are used to control a backwash inlet liquid flow in order to maintain the desired filter media bed expansion and by sending one or more discrete output signals that are used to stop the backwash inlet liquid flow when the filter backwash turbidity set point is reached.