Patent Application
20230059255
In various industries, fluids may be filtered to separate liquids and solids. For example, the fluids may be desalinated or treated to reduce contamination to reach an acceptable concentration for use. In various industries, such as, oil and gas wells, gas plants, desalination plants, wastewater treatment plants, and individual households, a sand filter may be used to treat fluids. Sand filters may have a filter bed within a tank. The filter bed may include layers of a filter medium (e.g., sand) therein. A pre-treated raw water enters the tank and flows through the filter medium. Additionally, the effluent (i.e., waste) drains through a drainage system in the lower part. After flowing through the filter medium, the pre-treated raw water is now treated, and the filtered water may exit the tank via the drainage system. Large process plants have also a system implemented to evenly distribute the raw water to the sand filters. In addition, a distribution system controlling the air flow is usually included. The distribution system may allow a constant air and water distribution to the sand filters. During the filtration process, a grain distribution of the filter medium may alter and accumulated solids from the filter bed may be removed.
In water treatment, backwashing operations may be conducted in sand filters to pump water backwards through the filter medium in the sand filters. Backwashing operations may include multiple steps to allow the filter medium to be reused. First, water is drained to a level that is above a surface of the filter bed within the sand filter. Next, an air scour cycle may occur. In the air scouring cycle, air may be pushed up through the filter medium causing the filter bed to expand breaking up the compacted grains of the filter medium and force the grains into suspension. After the air scour cycle, clean backwash water is forced upwards through the filter bed continuing the filter bed expansion and carrying the grains in suspension into backwash troughs suspended above the filter surface. Backwashing may continue for a fixed time. At the end of the backwash cycle, the upward flow of water is terminated, and the filter bed settles by gravity into its initial configuration. At this point, the filter medium may be rejuvenating and reused such that pre-treated raw water may re-enter the sand filter to be filtered until further backwash cycles are needed.
Conventional filtration systems in the water treatment industry typically require large and costly equipment to detect fluid levels and restore filter mediums. Such conventional filtration systems may also be more expensive because of the higher number of parts and components along with design and installation costs. Additionally, conventional filtration systems assume a fixed filter medium level to only measure a fluid level without addressing variable interfaces levels between the fluid and filter medium. Further, conventional filtration systems may require a set flow rate such that adjusting a fluid level in real-time may not be possible. Conventional filtration systems may also require determining a density of fluids to calculate fluid levels.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In one aspect, embodiments disclosed herein relate to a method for conducting a backwashing operation of a filter medium in a tank. A first height of the filter medium may be predetermined based on a first time measurement of a first signal transmitted from a first sensor positioned on a top of the tank. The method may include draining fluids in the tank to be one inch above the filter medium, and pumping air through the filter medium in an air scouring operation. The method may also include measuring a second height of the fluid within the tank based on a differential pressure reading of a second sensor and a third sensor positioned on the tank, and measuring a third height of an upper most surface of the fluid/filter medium mixture based on a second time measurement of a second signal transmitted by the first sensor. The method may further include determining if the upper most surface of the fluid/filter medium mixture is the fluid or the filter medium based on a difference between the first height and the second height, and maintaining the second height at one inch above the first height.
In another aspect, embodiments disclosed herein relate to a filtration system with a filter device. The filter device may include a tank, a drainage section at a lower most end of the tank, a filter medium above the drainage section and below an upper most end of the tank, and a plurality of sensors provided on the tank. A first sensor of the plurality of sensors may be on a top of the tank, a second sensor of the plurality of sensors may be on an upper most end of the tank, and a third sensor of the plurality of sensors may be on a lower most end of the tank. The first sensor may be configured to measure a first height of the filter medium. The second sensor and the third sensor may be configured to measure a second height of fluids within the tank. Additionally, air is configured to be pumped through the filter medium during an air scouring cycle. A control system may be operational coupled to the filter device, the control system may be configured to maintain the fluids at the second height at one inch above the first height during the air scouring cycle.
In yet another aspect, embodiments disclosed herein relate to a filtration system. The filtration system may include an untreated fluid reservoir fluidly connected to a filter device, untreated fluids from the untreated fluid reservoir are configured to be injected into the filter device; a treated fluid reservoir fluidly connected to the filter device, treated fluids from the filter device are configured to be injected the untreated fluid reservoir; and a waste fluid reservoir fluidly connected to the filter device, waste fluids from the filter device are configured to be injected the waste fluid reservoir. The filter device may include a tank; a drainage section at a lower most end of the tank; a filter medium above the drainage section and below an upper most end of the tank; a plurality of sensors provided on the tank, the plurality of sensors being configured to measure a first height of the filter medium within the tank and measure a second height of fluids within the tank; and a control system configured to maintain, by increasing or decreasing a volume of the fluids, the second height one inch above the first height based on data from the plurality of sensors.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
The following is a description of the figures in the accompanying drawings. In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility. Further, shapes of the elements as drawn are not necessarily intended to convey any information regarding the actual shape of the elements and have been solely selected for ease of recognition in the drawing.
In the following detailed description, certain specific details are set forth to provide a thorough understanding of various disclosed implementations and embodiments. However, one skilled in the relevant art will recognize that implementations and embodiments may be practiced without one or more of these specific details, or with other methods, components, materials, and so forth. For the sake of continuity, and in the interest of conciseness, same or similar reference characters may be used for same or similar objects in multiple figures. As used herein, the term “coupled” or “coupled to” or “connected” or “connected to” “attached” or “attached to” may indicate establishing either a direct or indirect connection, and is not limited to either unless expressly referenced as such. As used herein, fluids may refer to slurries, liquids, gases, and/or mixtures thereof without departing from the scope of the present disclosure.
Embodiments disclosed herein are directed to filtration systems to treat water in sand filters. More specifically, embodiments disclosed herein are directed to determining and controlling a fluid level within a sand filter. The different embodiments described herein may provide a filtration system having a sand filter with a plurality of sensors to determine a fluid level within a sand filter and a controller to control a volume of fluids entering the sand filter. By using the filtration system for water treatment operations disclosed herein, the filtration system may enhance a filtration process and prolong a filtration medium compared to conventionally used filtration systems. Further, a configuration and arrangement of the filtration system to determine and control fluid levels within a sand filter during water treatment operations according to one or more embodiments described herein may provide a cost-effective alternative to conventional filtration systems. For example, one or more embodiments described herein may increase the life of the filtration medium within the filtration system while the filtration medium in conventional filtration systems shorter life spans. The embodiments are described merely as examples of useful applications, which are not limited to any specific details of the embodiments herein.
In accordance with one or more embodiments, a filtration system includes a sand filter to treat water. In one or more embodiments, the sand filter may be a tank or vessel containing a filter medium. The tank may include one or more inlets to receive fluids and one or more outlets for fluids to exit the tank. Further, three or more sensors may be provided on or within the tank to measure, monitor, and transmit fluid and filter medium data within the tank to a control system. The control system may process the transmitted data to determine fluid levels within the tank to maintain a fluid level at a predetermined height with respect to the filter medium during air scouring in a backwashing operation.
Referring to
In one or more embodiments, the filter device 101 of the filtration system 100 is a sand filter to treat fluids from the untreated fluid reservoir 102, the treated fluid reservoir 103, and the waste fluid reservoir 104. For example, untreated fluid from the untreated fluid reservoir 102 enters the filter device 101 and flows through a filter medium within the filter device 101. The filter medium of the filter device 101 may treat/filter the untreated fluid such that treated fluids exit the filter device 101 and enter the treated fluid reservoir 103. From the treated fluid reservoir 103, the treated fluid may be transported to a destination for use. Additionally, during the treatment process, waste fluid is produced in the filter device 101 from the filter medium treating/filtering the untreated fluid. The waste fluid may exit the filter device 101 and enter the waste fluid reservoir 104. From the waste fluid reservoir 104, the waste fluid may be transported to a waste facility.
In some embodiments, fluid may flow between the various components of the filtration system 100. For example, treated fluids in the treated fluid reservoir 103 may be injected back into the filter device 101 for backwash operations or to be re-filtered. Additionally, the treated fluids in the treated fluid reservoir 103 may also be injected into to the untreated fluid reservoir 102 and the waste fluid reservoir 104 to dilute the fluids within the corresponding reservoirs (102, 104). It is further envisioned that the treated fluids may be injected into the untreated fluid reservoir 102 directly from the filter device 101. Further, waste fluids in the waste fluid reservoir 104 may be injected into the filter device 101 to be treated/filtered. It is further envisioned that nozzles 105 may be provided at inlets/outlets of the filter device 101 to control an injection rate of the fluids.
Still referring to
In some embodiments, the plurality of sensors 106 may transmit and receive information/instructions wirelessly and/or through wires via a control system 107. For example, each sensor of the plurality of sensors 106 may have an antenna (not shown) to be in communication (e.g., transmit and receive information/instructions) with the control system 107. The control system 107 may be onsite or at a remote location away from the site. For example, the control system 107 may be a control panel on or near the filter device 101, or in a housing such as a control room where an operator may be within to operator and view the filter device 101, or in a remote location away from the site.
In one aspect, the plurality of sensors 106 may be used to provide information such that a fluid level within the filter device 101, a height of filter medium within the filter device 101, and a height of the upper most level of a fluid/filter medium mixture within the filter device 101 may be obtained by the control system 107. By obtaining such information, the control system 107 may automatically control and adjust a volume of fluids entering the filter device 101 such the fluid level within the filter device 101 is maintained at a predetermined distance, such as at one inch (2.54 centimeters), above the height of filter medium, during backwashing operations, without inspection and reduce or eliminate human interaction with the filtration system 100.
In one or more embodiments, the control system 107 may include a computing system for implementing methods disclosed herein. The computing system may include a human machine interface (“HMI”) (shown in
The plurality of sensors 106 work in conjunction with the control system 107 to display information on the HMI. Having the filtration system 100 may significantly improve overall performance of the filter device 101, increase the life of the filter medium within the filter device 101, reduced risk of (non-productive time) NPT and many other advantages. Embodiments of the present disclosure describe control systems, measurements, and strategies to automating filtration operations (e.g., maintaining a fluid level at a predetermined height). It is further envisioned that the control system 107 may locally collect, analyze, and transmit data to a cloud in real-time to provide information, such as fluid levels, performance metrics, alerts, and general monitoring, to third parties remotely or through the HMI.
In one or more embodiments, the plurality of sensors 106 may communicate with the software application on the control system 107 to automate the filtration system 100, such as the filter device 101. In a non-limiting example, filtration operations may include an automated sequencing based on pre-approved sequence as shown in
With reference to
As illustrated in
In one or more embodiments, the control system 107 is pre-calibrated before the filter medium 111 is disposed within the tank 108. As shown in
For example, in accordance with one or more embodiments, total travel time=final time stamp—the initial time stamp. Based on the total travel time, the control system 107 may determine a height H of tank 108 to pre-calibrate the first sensor 106a. One skilled in the art will appreciate how pre-calibrating the first sensor 106a may allow the control system 107 to be used on any size and shape of the tank 108.
Now referring to
For illustration purposes, the filter medium 111 is a filter bed with a single or multiple filter media layers. For example, the filter medium 111 may include a first layer 112, a second layer 113 below the first layer 112, and a third layer 114 below the second layer 113. It is noted that while only three layers 112-114 are shown, this is shown for illustration purposes only and the filter medium may include any suitable number of layers without departing from the scope of the present disclosure. For example, the filter medium may be a single layer filter. From the first layer 112 to the third layer 114, a grain size of the filter medium 111 may gradually increase such that the smallest grain size is within the first layer 112 and the largest grain size is within the third layer 114. By having a gradually increase in the grain size of the filter medium 111, the first layer 112 may be a fine sand layer, the second layer 113 may be a coarse sand layer, and the third layer 114 may be a gravel support layer. In some embodiments, the filter medium 111 may be a monomedia such that the filter medium 111 is a one layered filter. Furthermore, a head space 117 may be formed above a top surface 116 of the filter medium 111. The head space 117 may be an empty space formed in the tank 108 above the filter medium 111.
In some embodiments, a biologically active film (not shown), such as a schmutzdecke layer, forms on top of the first layer 112. The schmutzdecke layer may consist of various biological materials such as a gelatinous biofilm matrix of bacteria, fungi, protozoa, rotifera and a range of aquatic insect larvae. As the schmutzdecke layer ages, more algae tend to develop, and larger aquatic organisms may be present including some bryozoa, snails and annelid worms. The schmutzdecke layer may improve, in conjunction with the filter medium 111, an efficiency of purification operations within the filter device 101.
Underneath the filter medium 111 at the lower most end 109, the tank 108 includes a drainage section 115. The drainage section 115 has nozzles 105 to inject various fluids from outlets of the filter device 101. For example, one nozzle 105 may be used to push treated fluids out of the filter device 101 while another nozzle 105 may be used to push waste fluids out of the filter device 101. In some embodiments, the drainage section 115 uses gravity to inject the various fluids out of outlets of the filter device 101. However, in backwashing operations, one of the nozzles 105 is used to inject treated water back through the drainage section 115 and upward through the filter medium 111.
In
Now referring to
In some embodiments, as the fluids enter the tank 108, the first sensor 106a is configured to periodically or continuously send signals downward, as described above, to provide data to the control system 107, such that the reference height Hr of the filter medium 111 may be updated in real-time. For this purpose, the first sensor 106a may be a non-contact guided wave radar transmitter. One skilled in the art will appreciate how even if the filter medium 111 is migrated and the level becomes lower, a new reference height Hr of the filter medium 111 may be redetermined by the methods above.
Now referring to
H=ΔP÷SG [Equation 1]
In Equation 1, H is the height of the fluid (e.g., the fluid level 118), AP is the differential pressure (e.g., the pressure difference of the measured pressure at the second sensor 106b subtracted from the measured pressure at the third sensor 106c), and SG is the Specific Gravity of the fluid. As such the fluids are continuously flowing and being controlled, one skilled in the art will appreciate how the Specific Gravity of the fluid is preprogrammed into the control system 107 or parameterized through the configuration of the differential pressure transmitter.
In one or more embodiments, the control system 107 may include a programmable logic controller (PLC) or logic solver to calculate level differences between the two sensors 106b, 106c. One skilled in the art will appreciate how determining the reference height Hr of the filter medium 111 and determining the differential pressure between the second sensor 106b and the third sensor 106c, the control system 107 determines the height Hf of the fluid within the tank 108. In some embodiments, to avoid capillary fill fluid at lower points in the filter device 101, the third sensor 106c may be an electronic remote sensor diaphragm. Additionally, while
In one or more embodiments, with fluids in the tank 108, the first sensor 106a sends signals to determine if an upper most level within the tank 108 is the height Hf of the fluid or the reference height Hr of the filter medium 111. As shown in
In some embodiments, the control system 107 then compares the determined height of the upper most level of the fluid/filter medium mixture to the height Hf of the fluid and the reference height Hr of the filter medium 111 to determine if the fluid or the filter medium 111 is the upper most level within the tank 108. By determining the height of the upper most level of the fluid/filter medium mixture, the control system 107 may adjust flow rates (at inlets and/or outlets) to maintain the height Hf of the fluid at a predetermined height within the tank 108. For example, as shown in
In reference to
In the backwashing operation, the fluids are drained to be one inch (2.54 centimeters) above the reference height Hr of the filter medium 111.
As the fluid continues to flow through the filter medium 111., the backwashing fluids start to settle in the tank 108, as shown in
In one or more embodiments, with the fluid level 119 calculated, the first sensor 106a sends a sixth signal to determine if an upper most level of the fluid/filter medium mixture within the tank 108 is the height Hf2 of the fluid or the reference height Hr of the filter medium 111. As shown in
In some embodiments, the control system 107 then compares the determined height of the upper most level of the fluid/filter medium mixture to the height Hf2 of the fluid and the reference height Hr of the filter medium 111 to determine if the fluid or the filter medium 111 is the upper most level within the tank 108. By determining the height of the upper most level within the tank 108, the control system 107 adjusts flow rates (at inlets and/or outlets) to maintain the height Hf2 of the fluid at a predetermined height within the tank 108. For example, as shown in
In one or more embodiments, the height Hf2 of the fluid determined, the control system 107 may send an alert or a command to start an air scouring cycle. In the air scouring cycle, the control system 107 may control an amount of air being pumped/injected (see block arrows A) through the filter medium 111. The pumped air expands and breaks up compacted grains of the filter medium 111, as well as suspend grains in the backwashing fluid. Further, in one or more embodiments, by having the height Hf2 of the backwashing fluid one inch (2.54 centimeters) above the reference height Hr of the filter medium 111, the air scouring cycle is enhanced such that the fluid level during air scouring is kept to a height that is most effective for air scouring, so that the life of the filter medium 111 is extended for further use. If the fluid is below the filter media, the air scouring is not effective and decreases the life of the filter medium 111. If the fluid is too high, above one inch (2.54 centimeters), the air cannot wash the particles to the first layer 112 of the filter medium 111. With the measurements taken by sensors/transmitters 106a, 106b, 106c, a fluid level in the filter device 101 may be adjusted precisely to be one inch (2.54 centimeters) above the upper layer of the filter medium 111, which is the recommended level for best air scouring results to break filtered particles to be washed away.
During backwashing operations, and before air scouring, the height Hf2 of the fluid and the height of the upper most level of the fluid/filter medium mixture is continuously monitored to maintain the height Hf2 of the fluid one inch (2.54 centimeters) above the reference height Hr of the filter medium 111. For example, as shown in
As shown in
After the air scouring cycle is completed, as shown by
In one or more embodiments, the control system 107 may run the backwashing operations for a fixed time or run the backwashing operations until the filter medium 111 reaches a predetermined quality requirement (e.g., settles back to approximate the initial configuration of the filter bed). Once the control system 107 stops the backwashing operations, the control system 107 may then send alerts and commands to restart treatment operations as shown by
With reference to
The function section 304 may include a command to adjust or stop flow into and out of the filter device 101. The HMI 300 may further display the various components with the filter device 101. For example, a replica of the filter medium 111 within the filter device 101 may be shown at the calculated heights. Additionally, a table section 305 may be displayed on the HMI 300 to display the various levels and heights within the filter device 101 that the control system (see 107 of
The HMI 300 of
In Block 400, as fluids are continuously pumped into the tank of the filter device, various parameters are measured to determine if a backwashing operation is needed to clean the filter medium within the tank. Specifically, in one or more embodiments, samples of fluids within the tank may be taken to determine a particle count in the filter medium. For example, the fluid sample (i.e., water) may be taken at the effluent to check the filter medium effectiveness. If the sampled fluid has a particle count higher than a threshold particle count, the filter medium is due to be cleaned via a backwashing operation. For example, if the particles per 0.05 ml of volume is greater than 200 or if the milligrams of solids per liter of water (mg/L) (total suspended solids TSS) is greater than 0.2, the filter medium 111 is due for cleaning. Additionally, in one or more embodiments, the fluid may be visually inspected to determine if cleaning is due based on the fluid color changing or if suspended solids are visible. Alternatively or subsequently, if particles are blocking the fluid from flowing through the filter medium, a differential pressure head between the lower most end 109 and the upper most end of the tank is higher than a threshold differential pressure head and require the filter medium to be cleaned. For example, the differential pressure head may be set to 25 psi (for high differential pressure) or 30 psi (for high-high differential pressure) to indicate the filter medium 111 needs to be cleaned. Once it is determined that the filter medium needs to be cleaned, an alert or a command may be sent to start a backwashing operation.
In Block 401, to start the backwashing operation, the filter device is isolated from other components in the filtration system. For example, valves may be closed to fluidly isolate the filter device to be offline. Once the filter device is isolated, in Block 402, the fluids are drained to be one inch (2.54 centimeters) above the filter medium. For example, the fluids may be drained out of the tank through the drainage section.
In Block 403, the fluid level of the fluids present in the tank is measured. For example, a differential pressure measurement may be taken between the second sensor and the third sensor and the data is transmitted to the controller. The controller then uses the measured differential pressure in Equation 1 (shown above) to determine the height of the fluid within the tank. In Block 404, with the fluid present in the tank, the height of the upper most level within the tank 108 is measured. The height of the upper most level within the tank 108 is determined by using the first sensor to send signals to reflect off the topmost surface (whether it is the fluid or the filter medium) and create time data packets from this signal.
In Block 405, the controller compares the various measurements to determine if the fluid or the filter medium is the upper most level within the tank. In Block 406, based on the various measurements, the controller determines if the fluid level is one inch (2.54 cm) above the height of the filter medium. If the fluid level is one inch (2.54 cm) above the height of the filter medium, an air scouring cycle is initiated in Block 407. In Block 408, during the air scouring cycle, fresh air is pumped into the tank/vessel through the filter medium, and the method of Blocks 403-406 may continuously repeat. For example, the air may be pumped for 3 minutes. That is, the air scouring cycle may be performed for 3 minutes, approximately. Returning back to Block 406, if the fluid level is not one inch (2.54 cm) above the height of the filter medium, in Block 409, the controller adjusts an injection/drainage rate of the fluids to reach the one inch mark above the height of the filter medium (e.g., sand). For example, if the fluid level is below one inch (2.54 cm), the controller will send a command to increase the volume of fluids being injected and/or decrease the volume of fluids being drained. Alternatively, if the fluid level is above one inch (2.54 cm), the controller will send a command to decrease the volume of fluids being injected and/or increase the volume of fluids being drained. From Block 409, the method may restart back at Block 403 to continue the method.
In Block 410, after the air scouring cycle is completed, backwash fluids are injected upward to go through the filter medium. For example, the backwash fluid may enter the tank via the drainage section and be pushed upward through the filter medium. The backwashing fluids may be continuously pumped upward through the filter medium to continue the filter medium expansion and carrying the particles in suspension. In Block 411, after being pumped through the filter medium for set amount of time, the backwashing fluids may be flushed out through the filter medium via backwash troughs. In Block 412, with the backwashing fluid flushed, the filter device is filled with a fluid to prepare the filter for use. In Block 413, the filter device is returned to service and back online. For example, valve may be opened to fluidly couple the filter device to other components in the filtration system and being treatment operations.
Implementations herein for operating the filtration system 100 may be implemented on control system having a computing system coupled to a controller in communication with the various components of the filtration system 100. Any combination of mobile, desktop, server, router, switch, embedded device, or other types of hardware may be used with the computing system for operating the filtration system 100. For example, as shown in
The computing system 500 may also include one or more input devices 510, such as a touchscreen, keyboard, mouse, microphone, touchpad, electronic pen, or any other type of input device. Additionally, the computing system 500 may include one or more output devices 508, such as a screen (e.g., a liquid crystal display (LCD), a plasma display, touchscreen, LED, cathode ray tube (CRT) monitor, projector, or other display device), a printer, external storage, or any other output device. One or more of the output devices may be the same or different from the input device(s). The input and output device(s) may be locally or remotely connected to the computer processor(s) 502, non-persistent storage 504, and persistent storage 506. Many different types of computing systems exist, and the input and output device(s) may take other forms.
The computing system 500 of
Data may also be presented through various audio methods. Data may be rendered into an audio format and presented as sound through one or more speakers operably connected to a computing device. Data may also be presented to a user through haptic methods. For example, haptic methods may include vibrations or other physical signals generated by the computing system. For example, data may be presented to a user using a vibration generated by a handheld computer device with a predefined duration and intensity of the vibration to communicate the data.
While the method and apparatus have been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope as disclosed herein. Accordingly, the scope should be limited only by the attached claims.
