FILTER MONITORING SYSTEM

Abstract

A method of determining flux of fluid across a filtration membrane includes: receiving an initial flow rate of fluid on a feed side; determining a change in concentration of a species between an initial concentration of a species in the fluid and a final concentration of the species in the fluid; determining a final flow rate of fluid flowing on the feed side based on the change in concentration of the species and the initial flow rate of fluid; determining flux of the fluid that has passed through the filtration membrane based on a difference between the initial flow rate of fluid and the final flow rate of fluid, and the surface area of the membrane; determining that the flux of the fluid is outside a predetermined threshold; and adjusting one or more parameters to maintain the flux of fluid through the filtration membrane below a threshold value.

Claims

1. A method of determining flux of fluid across a filtration membrane, the method comprising: receiving, from a sensor, an initial flow rate of fluid on a feed side before fluid flows past a filtration membrane; determining a change in concentration of a species between an initial concentration of the species in the fluid on the feed side and a final concentration of the species in the fluid on the feed side after the fluid has flowed past the filtration membrane; determining a final flow rate of fluid flowing on the feed side based on the change in concentration of the species and the initial flow rate of fluid; determining flux of the fluid that has passed through the filtration membrane based on a difference between the initial flow rate of fluid on the feed side and the final flow rate of fluid on the feed side, and a surface area of the membrane; determining that the flux of the fluid is outside a predetermined threshold; and adjusting one or more parameters to maintain the flux of fluid through the filtration membrane below a threshold value.

2. The method of claim 1, wherein the fluid is an aqueous fluid.

3. The method of claim 2, wherein the species is ions and/or particulates within the fluid.

4. The method of claim 1, wherein the adjusting of the one or more parameters includes adjusting a pressure of the fluid against the filtration membrane.

5. The method of claim 4, wherein the adjusting of the pressure of the fluid includes controlling pumps and/or valves at an inlet, permeate outlet, and/or reject outlet.

6. The method of claim 1, wherein the adjusting of the one or more parameters includes increasing a rate of the fluid driven past and/or through the filtration membrane.

7. The method of claim 6, wherein increasing the rate of the fluid includes determining hydraulic permeability of the filtration membrane and net driving pressure.

8. The method of claim 7, wherein the net driving pressure is a difference between trans-membrane pressure and osmotic pressure difference between the fluid on the feed side and a permeate side of the filtration membrane.

9. The method of claim 8, wherein the osmotic pressure is determined based on the concentration of the species in the fluid.

10. The method of claim 1, further comprising: determining that a severity of fouling is above a fouling threshold; conducting a cleaning process to maintain a permeate flow rate in constant flux operations and in constant pressure operations.

11. The method of claim 10, wherein the cleaning process includes utilizing acidic and/or alkaline solutions to restore system performance.

12. The method of claim 1, wherein at least one sensor module including the sensor is operable to determine data regarding the initial flow rate of the fluid, the initial concentration of the species in the fluid, the final concentration of the species in the fluid, and/or the final flow rate of the fluid.

13. The method of claim 12, wherein each of the at least one sensor module is operable to determine the data between a first fluid filtration module and a second fluid filtration module, wherein the fluid flows from the first fluid filtration module to the second fluid filtration module.

14. The method of claim 12, wherein the at least one sensor module is operable to determine the data across the filtration membrane.

15. The method of claim 12, wherein a sensor of each of the at least one sensor module is operable to determine the data at an inlet, a permeate outlet, and a reject outlet of a fluid processing pressure vessel including the filtration membrane.

16. The method of claim 12, wherein one or more of the at least one sensor module is operable to transmit the data to a central processing unit.

17. The method of claim 16, wherein the central processing unit is operable to adjust a pressure of the fluid when the flux of the fluid is outside a predetermined threshold.

18. The method of claim 17, wherein the central processing unit is operable to adjust the pressure of the fluid when the flux of the fluid is back within the predetermined threshold.

19. A system comprising: a sensor operable to determine an initial flow rate of fluid on a feed side before fluid flows past a filtration membrane; a central processing unit in communication with the sensor operable to: determining a change in concentration of a species between an initial concentration of the species in the fluid on the feed side and a final concentration of the species in the fluid on the feed side after the fluid has flowed past the filtration membrane; determining a final flow rate of fluid flowing on the feed side based on the change in concentration of the species and the initial flow rate of fluid; determining flux of the fluid that has passed through the filtration membrane based on a difference between the initial flow rate of fluid on the feed side and the final flow rate of fluid on the feed side, and a surface area of the membrane; determining that the flux of the fluid is outside a predetermined threshold; and adjusting one or more parameters to maintain the flux of fluid through the membrane below a threshold value.

20. The system of claim 19, to adjust the one or more parameters, the central processing unit is operable to control pumps and/or valves at an inlet, permeate outlet, and/or reject outlet to adjust a pressure of the fluid against the filtration membrane.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0174] Embodiments of the present invention will now be described, by way of non-limiting example, with reference to the accompanying drawings.

[0175] FIG. 1A: A side cross section view of a sensor module according to an embodiment,

[0176] FIG. 1B: A front view of a sensor module according to an embodiment;

[0177] FIG. 2: A side cross sectional view of two adjacent water filtration modules connected by a connector tube;

[0178] FIG. 3: A side cross sectional view of two adjacent water filtration modules connected by a sensor module according to an embodiment;

[0179] FIG. 4: An example water filtration module used in the art;

[0180] FIG. 5: An example water filtration membrane wrapped around a permeate tube from a water filtration module;

[0181] FIG. 6: A side cross sectional view of a water filtration system of the art;

[0182] FIG. 7: A side cross sectional view of a detection system according to an embodiment installed in a pressure vessel of a water filtration system; and

[0183] FIG. 8: A side cross sectional view of sensor module according to an embodiment.

DETAILED DESCRIPTION

[0184] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.

[0185] To facilitate the understanding of this invention, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as a, an and the are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as outlined in the claims.

[0186] The apparatus, systems and methods of the present disclosure are suitable for filtration of any appropriate fluid. The apparatus and systems of the present disclosure are exemplified below using a water filtration system such as those used in desalination plants that produce potable water from sea water. This example should not be construed as limiting on the applications of the apparatus, systems and methods of the disclosure and are merely illustrative of the underlying principles.

Example 1

[0187] With reference to FIGS. 1A and 1B there is provided a sensor module 1 comprising a tubular body 2 and a support 4 extending from the tubular body 2. The tubular body 2 comprises a first end 6 and a second end 8 and a channel 10 extending from the first end 6 to the second end 8. The support 4 comprises radial elements (acting as elongate elements, for example 12), an inner circular connecting portion 14 and an outer circular connecting portion 16. Control electronics 17 are provided adjacent the tubular body 2. The first end 6 comprises two sealing o-rings 18 and the second end 8 comprises two sealing o-rings 20. The tubular body 2 further comprises a first pressure transducer 22 (acting as a first pressure sensor) on the inside of the channel 10 and a second pressure transducer 24 (acting as a second pressure sensor) on the outside of the tubular body 2.

[0188] One radial element 12 comprises an array of conductivity sensors 26. The support 4 comprises a target device 28 at the extremity of the support 4 furthest from the tubular body 2. The target device 28 comprises a near-field induction coil configured to receive energy from an external initiator device and to modulate the carrier electromagnetic field of an external initiator device.

[0189] Typically, adjacent water filtration modules in water filtration plants are connected together with a connector pipe 30 that connects the permeate pipe 32 (acting as a permeate tube) of a first water filtration module 34 to the permeate pipe 36 (acting as a permeate tube) of the adjacent second water filtration module 38 (see FIG. 2, for example). An example connector pipe 30 is a cylindrical tube having an outer diameter of 25 mm with first and second ends comprising two o-rings to seal the connection between the connector pipe and a permeate pipe, the first and second ends having an outer diameter of 27 mm. With reference to FIG. 3, the connector pipe 30 is replaced with a sensor module 1. The sensor module 1 is installed between adjacent water filtration modules. The first end 6 of the tubular body 2 is inserted into the permeate tube 40 of a first water filtration module 42 and the second end 8 of the tubular body 2 is inserted into the permeate tube 44 of a second water filtration module 46. The o-rings 18 of the first end 6 form a seal between the inner surface of the permeate tube 40 of the first water filtration module 42 and the tubular body 2 and the o-rings 20 of the second end 8 forms a seal between the inner surface of the permeate tube 44 of the second water filtration module 46 and the tubular body 2. The support 4 extends from the tubular body 2 across the anti-telescoping device 48 (acting as a cap) of the first and second water filtration modules 42, 46 such that the target device 28 is positioned adjacent to the outside 50 of the first and second water filtration devices 42, 46.

Example 2

[0190] An example system within which the sensor module of example 1 can be used is a sea water filtration/desalination plant where sea water is processed in a desalination process to produce substantially pure water.

[0191] Desalination processes typically pump sea water or another source of salty water (the feed) to be processed through a plurality of water filtration modules provided in series within a pressure vessel (acting as a fluid processing pressure vessel). With reference to FIGS. 4-6 example industry standard water filtration modules 50 comprise a filtration membrane 52 wrapped around a perforated permeate collection pipe 54 (acting as a permeate tube). The filtration membranes 52 are retained within the water filtration module 50 by anti-telescoping devices (acting as caps) that prevent the filtration membrane 52 from being pushed out of the water filtration module 50 when water is urged through the water filtration module 50 at high flow rates during use. The filtration membrane 52 comprises a filtration membrane envelope that comprises a first membrane 56, a permeate spacer 58 and a second membrane 60 such that during use water flows across the first membrane 52 and the second membrane 60 into the permeate spacer 58. From the permeate spacer 58 the water flows into the perforated permeate collection pipe 54. The filtration membrane 52 thereby filters salt and other impurities from the water such that substantially pure water 53 is collected in the perforated permeate collection pipe 54.

[0192] The feed 55 that enters a water filtration module 50 has a given salinity and the feed that exits the other side of the water filtration module 50 (the reject) typically has a higher salinity due to the reduction in the volume of water in the feed as water (permeate) is filtered out of the feed into the permeate collection pipe 54.

[0193] Accordingly, the feed 55 entering a second water filtration module will have a higher salinity and a lower pressure, and a lower flow rate due to the reduction in volume and hydraulic resistance in the first module, than that of the feed entering the preceding first water filtration module.

[0194] In some facilities the pressure vessel may retain seven water filtration modules provided in series. Accordingly, the feed flows through the water filtration system from a first water filtration module to the seventh water filtration module via the second through sixth water filtration modules in sequence.

[0195] Alternative pressure vessels may retain two, three, five, ten or fourteen or any other number of water filtration modules, for example.

[0196] A pressure vessel 62 has an inlet 64 that feeds into a first water filtration module 66. The pressure vessel 62 further includes a permeate outlet 68 to thereby allow the permeate to be removed from the pressure vessel 62. The pressure vessel 62 includes a reject outlet 69 to thereby allow the feed that has passed through all water filtration modules 70 (also known as reject 57) to flow out of the pressure vessel 62. The resulting reject may then flow into another pressure vessel for further processing. The pressure vessel 62 of this example retains seven water filtration modules provided in series.

[0197] Typically, with reference to FIG. 7, the permeate collection pipe 80 of a first water filtration module 82 feeds into the permeate collection pipe 84 of a second water filtration module 86 and so on such that the permeate collection pipes of the series of water filtration modules form a continuous permeate collection pipe.

[0198] Previously, operators of a desalination plant that comprises many banks of pressure vessels, for example, would use data obtained from feed at the inlet of the pressure vessel and at the reject outlet of the pressure vessel to determine the performance of the each bank of pressure vessels. Typically, a measured change in the pressure drop across the pressure vessel as a whole or a change in the transmembrane pressure or of the overall salt passage was indicative of either a failure or fouling of membranes within the series of water filtration modules, which would result in the specific bank of pressure vessels concerned being taken off line and a course of treatment be applied to the specific pressure vessel.

[0199] In this example, a sensor module 1 according to example 1 is provided between adjacent water filtration modules such that a sensor module 1 is provided after each water filtration module such that pressure data and conductivity data can be provided for each water filtration module. For example, as shown in FIG. 7, a sensor module 1 is provided in the permeate collection pipe 80 of a first water filtration module 82 and the permeate collection pipe 84 of a second water filtration module 86. Sensors (not shown) are also provided at the inlet 64 of the pressure vessel 62 to determine the pressure and conductivity of the fluid entering the pressure vessel 62 during use and sensors (not shown) are provided at the reject outlet.

[0200] Referring to FIG. 7, a data collection module 100 is provided on the outside of the pressure vessel 62 for each sensor module 1. The data collection module 100 comprises an initiator device 102 configured to communicate with and to power the corresponding sensor module 1 via the target device 28 of that sensor module 1. Each data collection module 100 is positioned on the pressure vessel 62 such that the initiator device 102 of that data collection module 100 is positioned adjacent to the target device 28 of the sensor module 1.

[0201] During use, sea water is urged under high pressure (up to approximately 100 bar) into the inlet 64 of the pressure vessel 62 such that the sea water flows through each water filtration module sequentially. Water is removed from the sea water via the permeate outlet 68 that has collected water from each water filtration module.

[0202] Each sensor module 1 collects pressure data and conductivity data and transmits that data to the corresponding data collection module 100. Each data collection module 100 transmits the received data to a central processing unit (not shown) where the data is collated and analyzed. In addition, the data from the inlet 64 and the reject outlet 80 is also transmitted to the central processing unit for collation and analysis.

[0203] The central processing unit calculates the change in pressure (P), the transmembrane pressure (TMP), salt passage (from measured conductivity) and the change in conductivity (C) across each water filtration module. A change in any or all of the parameters for a given water filtration module from normal operation values (acting as reference data) for that water filtration module is indicative of either failure or fouling of that specific water filtration module.

[0204] Typically, a change in P compared to reference data for one of the first two water filtration modules in the series of water filtration modules is indicative of biofouling and therefore, an operator knows that the likely corrective action to take is to apply or regulate the dosage of a biocide or similar anti-biofouling composition to the modules in that pressure vessel.

[0205] Typically, a change in TMP and/or transmembrane flux (TMF) compared to reference data for one of the final two water filtration modules in the series of water filtration modules is indicative of mineral scaling and therefore, an operator knows that the likely corrective action to take when the TMP or TMF for one of the final water filtration modules changes from normal operation TMP or TMF is to apply or regulate the dosage of an anti-scalant composition to the feed solution for that pressure vessel.

[0206] The data is provided regularly to the operator such that fouling incidents can be addressed early by an operator to thereby reduce downtime for the water filtration system and to minimize the risk of damage to the water filtration modules.

[0207] Provision of the C for the feed/reject water for each water filtration module also allows the flux of water through the filtration membranes of the water filtration modules, known as trans-membrane flux, to be calculated.

[0208] As has been previously described above, the removal of water from sea water by a water filtration module reduces the volume of fluid but retains the same amount of salt. Accordingly, the concentration of salt increases directly in proportion to the change in volume of water within the sea water fed into a subsequent water filtration module (the feed water). The measured conductivity of feed water is proportional to the salt concentration of the feed water.

[0209] The measurement of C per water filtration module along with the known total feed flow rate into the pressure vessel allows an operator to determine the change in concentration of salt in the sea water across the water filtration module and therefore to determine the change in volume of the sea water to thereby determine the flux of water through the filtration membrane per water filtration module (the trans-membrane flux).

[0210] Determination of the trans-membrane flux per water filtration module allows an operator to identify any change in the trans-membrane flux of any individual water filtration module to thereby identify any reduction in the trans-membrane flux early and to thereby apply a corrective action if necessary.

[0211] Further, the ability to monitor the trans-membrane flux per water filtration module over time allows any change in trans-membrane flux for any given water filtration module that may be associated with the onset of critical flux to be detected. Accordingly, the operator may determine that critical flux is approaching for one specific water filtration module and may take preventative action to prevent critical flux from occurring. For example, the operator may decrease the pressure inside the pressure vessel by opening a reject outlet valve to thereby reduce the driving pressure and increase the cross-flow to clear contamination and prevent critical flux being exceeded.

Example 3

[0212] With reference to FIG. 8, a sensor module 200 comprises a tubular body 202. The tubular body 202 comprises a first end 204, a central portion 206 and a second end 208 opposed to the first end 204. A channel 210 extends from the first end 204 to the second end 208. The first end 204 comprises two sealing o-rings 212 and the second end 208 comprises two sealing o-rings 214. The central portion 206 further comprises a first pressure sensor 216 on the inside of the channel 210 of the tubular body 202 and a second pressure sensor 218 on the outside of the tubular body 202. The central portion 206 further comprises a battery 220 and a data transmitter 222.

[0213] The first end 204 of the tubular body 202 is configured to be inserted into the permeate pipe (acting as a permeate tube) of a first fluid filtration module and the second end 208 of the tubular body 202 is configured to be inserted into the permeate pipe of a second fluid filtration module that is adjacent to the first fluid filtration module in a series of fluid filtration modules. The first pressure sensor 216 is exposed to fluid flowing through the channel 210 of the tubular body 202. The second pressure sensor 218 is exposed to fluid flowing between the adjacent fluid filtration modules past the exterior of the tubular body 202.

[0214] During use, the sensor module 200 is powered by the battery 220. Pressure data is determined by the first pressure sensor 216 and the second pressure sensor 218 and transmitted to an external device by the data transmitter 222.

Example 4

[0215] A water filtration system (not shown) comprises fourteen water filtration modules provided in series within two pressure vessels (seven water filtration modules retained in a first pressure vessel and seven water filtration modules retained within a second pressure vessel) connected in series. The arrangement of pressure vessels comprises an inlet, a permeate outlet and a reject outlet with the reject outlet of the first pressure vessel being connected to the inlet of the second pressure vessel and the permeate outlet of the first pressure vessel being connected to the permeate tube of the second pressure vessel. Each water filtration module corresponds to a water filtration module as described in Example 2. A sensor module according to Example 3 is provided between the first and second water filtration modules, the second and third water filtration modules, the fifth and sixth water filtration modules, and the sixth and seventh water filtration modules of the first pressure vessel and of the second pressure vessel. A sensor module is also provided at the inlet of the first pressure vessel and the second pressure vessel. A sensor module is also provided at the reject outlet of the first pressure vessel and the reject outlet of the second pressure vessel.

[0216] A data collection module is provided on the outside of the pressure vessel for each sensor module. The data collection module comprises an initiator device configured to communicate with the corresponding sensor module via the transmitter of that sensor module. Each data collection module is positioned on the pressure vessel such that the initiator device of that data collection module is positioned adjacent to the transmitter of the sensor module.

[0217] During use, data is collected as described for Example 2. The operator is presented with data for the first, second, sixth and seventh water filtration modules for each pressure vessel to allow them to monitor the performance of each water filtration module in each pressure vessel and to thereby detect a drop in performance of any of these water filtration modules independently. As a result the operator is able to address any drop in performance for any of the monitored water filtration modules early to thereby ensure that the water filtration system runs at maximum efficiency.

[0218] While there has been hereinbefore described approved embodiments of the present invention, it will be readily apparent that many and various changes and modifications in form, design, structure and arrangement of parts may be made for other embodiments without departing from the invention and it will be understood that all such changes and modifications are contemplated as embodiments as a part of the present invention as defined in the appended claims.