System and method for separating particles in fluid

Abstract

A separation element including a microfluidic channel may use a hydraulic separator or a flow routing element to separate particles in a fluid. A particle sensor may be used to count particles in each microfluidic channel. A unique orifice pattern may be used to facilitate the use of a shared particle sensor for multiple microfluidic channels. The separation element may be used in various systems such as engine fuel systems, bulk fuel systems, hydraulic particulate filters, and hydraulic degassing enhancers.

Description

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 942,009, filed on November 29, 2019, the disclosure of which is hereby incorporated by reference in its entirety.

[0002] This disclosure relates to separating particles. In particular, this disclosure relates to separating particles in a fluid.

[0003] In some systems, such as in an engine fuel system, a bulk fuel system, a hydraulic system, or other systems that process or store fluids, particles dispersed in the fluid can cause problems. For example, water particles (or micro-droplets) in fuel can cause problems in an engine fuel system of an internal combustion engine. The water in the fuel can damage fuel injectors due to corrosion or vaporization during the combustion process. Damage to the fuel injectors can lead to various problems in engine operation, such as failure to meet jurisdictional emission standards. Damage to the fuel injectors may require repair or maintenance. For commercial or industrial vehicles, the cost of reduced operating time can be particularly high. Generally, gas, liquid, or solid particles dispersed in a fluid can cause problems in various fluid systems, such as bulk fuel systems, hydraulic systems, etc. Conventional fluid filters capture particles in a media structure. Over time, the media structure can become clogged, requiring maintenance or replacement of the filter. SUMMARY

[0004] The technology of this disclosure generally relates to concentrating certain particles in a fluid in various fluid systems and separating such particles from the fluid or from other sized particles. Generally, a fluid system can include a particle separation element (such as a hydrocyclone element) to concentrate particles within a specific size range. The particle separation element can include an inlet and an outlet having at least two flow branches. Particles within a specific size range can be concentrated into one of the two flow branches. In some embodiments, particles above a threshold size range are concentrated into one of the two flow branches. Any remaining particles can flow through the at least two flow branches. In some embodiments, the particle separation element can be used to supplement or replace a fluid filter.

[0005] In one aspect, the present disclosure relates to a hydroseparator. A system includes a hydroseparation element having one or more hydroseparators, each hydroseparator defining a curved microfluidic channel in fluid communication. Each microfluidic channel defines an inlet and an outlet, the inlet being configured to receive a fluid and particles dispersed in the fluid, wherein the particles have a different composition than the fluid, and the outlet includes a first flow branch and a second flow branch. At a predetermined flow rate, each microfluidic channel is configured to direct any particles exceeding a corresponding threshold size into the second flow branch and direct any remaining particles into the first and second flow branches. The system further includes a particle sensor positioned along one or more of the hydroseparators, the particle sensor being configured to provide signal data representative of a signal corresponding to the fluid and the particles in the fluid. The system further includes a controller operatively coupled to the particle sensor to receive the signal data and operatively coupled to a fluid pump in fluid communication with the hydroseparation element. The controller is configured to: control the fluid pump to direct the fluid through the hydroseparation element, determine, based on the signal data from the particle sensor, whether a threshold level of particles is present in at least one of the microfluidic channels, and in response to determining that a threshold level of particles is present in at least one of the microfluidic channels, control the flow rate through the hydroseparation element to direct the fluid through the hydroseparation element at the predetermined flow rate so as to concentrate any particles exceeding a corresponding threshold size into the second flow branch of at least one of the microfluidic channels.

[0006] In another aspect, the present disclosure relates to a particle diverter. A system includes a particle separation element. The particle separation element includes one or more microfluidic channels in parallel fluid communication. Each microfluidic channel defines an inlet and an outlet, the inlet being configured to receive a fluid and particles dispersed in the fluid, wherein the particles have a different composition than the fluid, and the outlet includes a first flow branch and a second flow branch. The system further includes a flow path selection element positioned along at least one flow branch of at least one of the outlets. The system further includes a particle sensor positioned along one or more of the microfluidic channels, the particle sensor being configured to provide signal data representative of a signal corresponding to the fluid and the particles dispersed in the fluid. The system includes a controller operatively coupled to at least one flow path selection element and operatively coupled to the particle sensor to receive the signal data. The controller is configured to: control the flow path selection element to direct a fluid flow to the first flow branch of at least one of the outlets of at least one of the microfluidic channels, determine, based on the signal data from the particle sensor, whether a threshold level of particles is present in at least one of the microfluidic channels, and in response to determining that a threshold level of particles is present in at least one of the microfluidic channels, control the flow path selection element to direct the fluid flow to the second flow branch of at least one of the microfluidic channels.

[0007] In another aspect, the present disclosure relates to a particle sorter. A system includes a hydroseparation element that includes a plurality of hydroseparators in serial fluid communication. The plurality of hydroseparators includes at least a first hydroseparator and a second hydroseparator. Each hydroseparator defines a curved microfluidic separation channel to separate particles in different size ranges. Each microfluidic separation channel defines an inlet and an outlet. The inlet is configured to receive a fluid containing particles. The outlet includes a first flow branch and a second flow branch. At a particular flow rate, each microfluidic separation channel is configured to direct any particles above a corresponding threshold size into the second flow branch and direct any remaining particles into the first flow branch and the second flow branch, wherein the first flow branch of the first hydroseparator is in fluid communication with the inlet of the second hydroseparator. The system further includes a microfluidic sensing element in fluid communication with the hydroseparation element. The microfluidic sensing element includes a plurality of microfluidic sensing channels, each microfluidic sensing channel in fluid communication with a different flow branch of the hydroseparation element. The plurality of microfluidic sensing channels includes at least: a first microfluidic sensing channel in fluid communication with the second flow branch of the first hydroseparator to receive any particles above a first threshold size, and a second microfluidic sensing channel in fluid communication with the second flow branch of the second hydroseparator to receive any particles above a second threshold size, wherein the first threshold size is greater than the second threshold size.

[0008] In yet another aspect, the present disclosure relates to an orifice pattern. A system includes a plurality of microfluidic sensing channels, each microfluidic sensing channel configured to receive a flow of fluid and particles dispersed in the fluid. The particles have a different composition than the fluid. The system further includes a light source configured to direct a beam of a certain frequency band along a path through the plurality of microfluidic sensing channels. The frequency band is selected such that the particles and the fluid have different light absorption rates. The system further includes an orifice element defining a plurality of light orifices having different sets of light orifices aligned with each microfluidic sensing channel. Each set of light orifices defines a unique spacing pattern along the corresponding microfluidic sensing channel. The system further includes a light detector positioned to receive the beam in a sensing region after the beam passes through the plurality of light orifices of the orifice element and through the plurality of microfluidic sensing channels. The light detector is configured to provide a signal representative of the amount of light of the frequency band remaining after passing through the plurality of microfluidic sensing channels. Further, the system includes a controller operatively coupled to the light detector and configured to: determine signal data based on the signal from the light detector, determine whether a particle has passed through the sensing region based on the signal data, and determine the unique spacing pattern associated with the particle passing through the sensing region based on the signal data.

[0009] In yet another aspect, the present disclosure relates to water droplet detection. A system includes a system according to the present disclosure, wherein the particles include a second fluid different from the fluid.

[0010] In a further aspect, the present disclosure relates to an engine fuel system. A system includes a fuel line configured to deliver fuel to a fuel injector system. The system further includes a hydroseparation element having one or more hydroseparators, each hydroseparator defining a curved microfluidic channel to separate particles in the fuel. Each microfluidic channel defines an inlet and an outlet, the inlet being in fluid communication with the fuel line to receive fuel, and the outlet including a first flow branch in fluid communication with the fuel line to supply fuel to the fuel injector system and a second flow branch to receive particles within a specific size range.

[0011] In another aspect, the present disclosure relates to a bulk fuel system. A system includes a fuel line configured to deliver fuel from a bulk fuel storage tank to a vehicle fuel tank. The system further includes a hydroseparation element having one or more hydroseparators, each hydroseparator defining a curved microfluidic channel to separate particles in the fuel. Each microfluidic channel defines an inlet and an outlet, the inlet being in fluid communication with the fuel line to receive fuel, and the outlet including a first flow branch in fluid communication with the fuel line to supply fuel to the vehicle fuel tank and a second flow branch to receive particles within a specific size range.

[0012] In yet another aspect, the present disclosure relates to a hydraulic particle filter. A system includes a hydraulic fluid line configured to deliver hydraulic fluid from a hydraulic pump to a hydraulic component. The system further includes a hydroseparation element having one or more hydroseparators, each hydroseparator defining a curved microfluidic channel to separate particles in the hydraulic fluid. Each microfluidic channel defines an inlet and an outlet, the inlet being in fluid communication with the hydraulic fluid line to receive hydraulic fluid from the hydraulic pump, and the outlet including a first flow branch in fluid communication with the hydraulic fluid line to supply hydraulic fluid to the hydraulic component and a second flow branch to receive particles within a specific size range.

[0013] In yet another aspect, the present disclosure relates to enhanced hydraulic degassing. A system includes a hydraulic fluid return line configured to convey hydraulic fluid from the hydraulic component to a hydraulic pump. The system further includes a hydraulic separation element having one or more hydraulic separators, each hydraulic separator defining a curved microfluidic channel to separate particles in the hydraulic fluid. Each microfluidic channel defines an inlet and an outlet, the inlet being in fluid communication with the hydraulic fluid line to receive hydraulic fluid from the hydraulic pump, and the outlet including a first flow branch in fluid communication with the hydraulic fluid line to provide hydraulic fluid to the hydraulic pump and a second flow branch to receive particles within a specific size range. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various embodiments of the present disclosure are shown in the drawings, which are summarized as follows:

[0015] Figure 1 is a conceptual diagram showing an example of a fluid system according to the present disclosure, the fluid system including a particle separation element configured to receive a fluid stream from a fluid source.

[0016] Figure 2 is a conceptual diagram showing an example of a fluid system that can be used with Figure 1 the particle separation element to process fuel on a machine.

[0017] Figure 3 is a conceptual diagram showing an example of a fluid system that can be used with Figure 1 the particle separation element to process bulk fuel.

[0018] Figure 4 is a conceptual diagram showing an example of a fluid system that can be used with Figure 1 the particle separation element to convey hydraulic fluid.

[0019] Figure 5 is a conceptual diagram showing an example of a fluid system that can be used with Figure 1 the particle separation element to degas hydraulic fluid.

[0020] Figure 6 is a conceptual diagram showing an example of an optical or light-based particle sensor that can be used in Figure 1 the particle sensor.

[0021] Figure 7 is a conceptual diagram showing an example of an arrangement of a particle sensor using Figure 1 the microfluidic channel.

[0022] Figure 8is a conceptual diagram showing another example of an arrangement of a particle sensor used in conjunction with a microfluidic channel Figure 1 The conceptual diagram of another example of the arrangement of the particle sensor used

[0023] Figures 9 to 10 is a conceptual diagram showing the use of Figure 1 The particle sensor together with a particle separation element and a microfluidic sensing element in another arrangement

[0024] Figures 11A to 11B is a conceptual diagram showing an example of a technique that can be used with Figure 1 The particle sensor to use a shared photodetector to count the number of particles in multiple microfluidic channels

[0025] Figure 12 is a conceptual diagram showing an example of a fluid system that can be used with Figure 1 The particle separation element to remove particles

[0026] Figures 13A to 13D are respectively an image and a graph showing a hydroseparator device and pixel intensity versus channel position

[0027] Figure 14 is a conceptual diagram showing the relative positions of the angles around Figures 13A to 13D The hydroseparator device

[0028] Figure 15 is a diagram showing Figures 13A to 13D The graph of the concentration percentage of the hydroseparator device versus the channel length DETAILED DESCRIPTION

[0029] In the following detailed description, several specific embodiments are referred to. It should be understood that other embodiments are contemplated and can be formed without departing from the scope or spirit of the present disclosure. Accordingly, the following detailed description should not be taken in a limiting sense

[0030] The present disclosure provides techniques for concentrating certain particles in a fluid and separating those particles from the fluid or other sized particles in various fluid systems. Generally, a fluid system can include a particle separation element (such as a hydroseparation element) to concentrate particles within a particular size range. The particle separation element can include an inlet and an outlet having at least two flow branches. Particles within a particular size range can be concentrated into one of the two flow branches. In some embodiments, particles above a threshold size range are concentrated into one of the two flow branches. Any remaining particles can flow through the at least two flow branches. In some embodiments, the particle separation element can be used to supplement or replace a fluid filter

[0031] Particle separation elements (which may include hydro separation elements) can be used as an alternative or supplement to filters. In particular, particle separation elements can be used to concentrate particles above a critical size into a portion of the fluid flow. This portion of the fluid flow can be removed from the system, thereby removing most of the particles above the threshold size. In some cases, this may replace some or all of the functions of a filter. The performance of the particle separation element does not change over time and does not require periodic replacement. In some embodiments, a filter can be used downstream of the particle separation element to remove particles below the threshold size. Further, in some embodiments, the particles concentrated by the particle separation element are filtered. This can be done at a lower surface velocity compared to a system without a particle separation element and thus results in a lower filter pressure drop and longer filter life.

[0032] Particle separation elements (which may include hydro separation elements) can also be used to sort particles of different sizes. In some applications, a threshold size can be determined. The particle separation element can be designed to concentrate particles above the threshold size into an aggregated fluid portion of the fluid flow. The aggregated portion of the fluid flow can be removed from the system. This technique can be used to concentrate particles for particle counting. This technique can also be used to separate different types of particles or to aggregate certain materials for collection.

[0033] Microfluidic particle sensors or microfluidic sensing elements can be used to detect individual contaminants in a fluid (such as a liquid flow). A separator or staging stage can be positioned upstream of the particle sensor. The staging stage or particle separation element can separate particles into different fluid streamlines based on particle size. For example, this can be done by Dean Flow Separation. Once the particles are in the streamlines based on their particle size, these streamlines are fed into different sensing channels of the microfluidic sensing element. The sensing channels are associated with a particle sensor that counts the number of particles. By knowing the number of particles in each sensing channel, an approximate particle size distribution can be determined. The sensor can be an optical sensor, a capacitance sensor, a magnetic sensor, or other sensors. Alternatively, the particle sensor can consist only of microfluidic channels and sensors. Using microfluidic channels can improve the sensitivity to individual contaminants compared to other techniques such as Mie scattering. Signal processing can also be used to identify the type of contaminant.

[0034] Further, a particle separation element that may include a hydroseparation element can be used to selectively remove particulate waste. In some cases, only particles above a certain size can be removed from the system. Uses of selective particulate waste removal can include, but are not limited to: removing or aggregating fat in milk (fat is typically agglomerated at 0.1 to 15 microns), removing or aggregating orange juice pulp, removing contaminants in semiconductor processing fluids, and removing ink agglomerates in industrial ink processing. In one example related to a wafer polishing slurry, the particle separation element can be designed to remove particles above a threshold size, which may be agglomerates or impurities, while allowing particles below the threshold size to pass through. Definition Particle

[0035] As used herein, the term "particle" refers to a discrete amount of material that can be dispersed in different fluids. Non-limiting examples of materials that may form particles include dirt, metal, air bubbles, and microdroplets. In one particular example, microdroplets can be dispersed in a hydrocarbon fluid (such as gasoline or diesel fuel) to form an emulsion. In another example, air bubbles may be dispersed in a hydraulic fluid. Upstream / downstream

[0036] As used herein, the term "downstream" refers to the direction along the fluid flow. The term "upstream" refers to the direction opposite to downstream, or opposite to the direction of the fluid flow. Microfluidic channel

[0037] As used herein, the term "microfluidic channel" refers to a channel having at least one dimension less than 1 millimeter (1000 microns). A microfluidic channel can have a channel width less than 1000 microns, a channel height (or depth) less than 1000 microns, or both. In some embodiments, for higher flow rate applications, at least one dimension of the microfluidic channel can be greater than 1 millimeter. In some embodiments, at least one dimension of the microfluidic channel is greater than or equal to 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 millimeters, or less than or equal to 10, 9, 8, 7, 6, 5, 4, 3, or 2 millimeters. Generally, the channel can have any suitable length to provide a suitable pressure drop balanced with a suitable particle concentration.

[0038] A microfluidic channel can be described by a cross-sectional area width × height. In some embodiments, the cross-sectional area of the microfluidic channel can be less than 10, 9, 8, 7, 6, 5, 4, 3, or 2 square millimeters.

[0039] A microfluidic channel can also be described by a hydraulic diameter. For example, for a microfluidic channel having a rectangular cross-section, the hydraulic diameter can be calculated as follows: where DH is the hydraulic diameter. Other cross-sectional shapes can be calculated according to techniques known to those of ordinary skill in the art who benefit from this disclosure. In some embodiments, the hydraulic diameter of the microfluidic channel can be less than 5, 4, 3, 2, or 1 millimeter. In at least one embodiment, the hydraulic diameter of the microfluidic channel can be less than 1 millimeter. Hydraulic separator

[0040] As used herein, the term "hydraulic separator" refers to a curved fluid channel that includes at least an inlet and an outlet, the inlet for receiving a fluid stream, and the outlet including at least two branches that divide the fluid stream. The fluid channel can be a microfluidic channel. The inlet can receive a fluid that can contain particles of various sizes. At a particular flow rate, the hydraulic separator is configured to concentrate any particles larger than a threshold size into one branch. Any remaining particles are not concentrated in the fluid stream. The remaining particles can be separated among all the branches, e.g., based on the volume fraction or outlet flow ratio associated with each branch. The hydraulic separator can be designed based on at least one or more of the following parameters: Dean number, Reynolds number, hydraulic diameter, radius of curvature, target flow rate, target pressure drop, critical particle size, fluid viscosity, operating temperature (which may affect fluid viscosity), outlet flow ratio, or any combination of these parameters. The hydraulic separator can also be described as a Dean flow separator.

[0041] Generally, the hydraulic separator includes a curved microfluidic channel that is designed to concentrate particles larger than a threshold size onto the curved inner wall. The cross-sectional area of the microfluidic channel limits the maximum particle size that can enter the microfluidic channel. The device defines a geometry (such as width, height, radius of curvature, and channel length) that is designed to concentrate particles in a known fluid at a particular flow rate or flow rate range. Then, by removing a portion of the fluid near the inner wall, the concentrated particles near the inner wall can be removed from the system. In other embodiments, depending on the geometry of the device and operating conditions, the particles and waste stream can alternatively be concentrated near the outer wall. The design of the device may depend on the application flow rate, fluid properties (such as viscosity and density), and threshold particle size. The hydraulic separator can act as a filter or pre-filter in the system.

[0042] Curved microfluidic channels can be used to concentrate particles of a predetermined size under appropriate flow conditions. In a curved channel or pipe under laminar flow conditions, the inertia of the fluid creates a pressure gradient across the channel. To mitigate the pressure gradient, two types of helical flows, known as Dean flows (sometimes also called secondary flows), may form. Dean flows can exert a drag force on any particles in the fluid. In larger channels, the particles can sweep along the channel in a helical motion. When the channel is made smaller, such as in a microfluidic channel, the Dean flow can be balanced by two additional forces such that the particles can be trapped and concentrated on the inner wall of the curved channel. These forces can be described as shear-induced lift and wall-induced lift, where the shear-induced lift causes a lift force towards the wall and, as the particle approaches the wall, the wall-induced lift pushes the particle away from the wall due to the confinement of the fluid flow. The particles can be concentrated into specific streamlines within the curved channel. Concentrating particles in this way can be referred to as hydrodynamic separation or Dean flow separation. Flow routing element

[0043] As used herein, a "flow routing element" refers to a component configured to allow for selective routing of a fluid flow exiting a fluid channel. Non-limiting examples of components of a flow routing element include valves or solenoids. In one example, a flow routing element can include one or more valves configured to divert the flow in any suitable manner to one or more branches. Dean number

[0044] The Dean number describes the fluid behavior in a curved pipe and accounts for the inertial, centripetal, and viscous forces acting on the fluid. In various embodiments, a system is configured to have a Dean number between 5 and 25. The Dean number is defined as: where Re is the Reynolds number and Rc is the radius of curvature of the fluid channel. Reynolds number

[0045] The Reynolds number describes the ratio of inertial forces to viscous forces and is defined as: where ρ is the fluid density, U is the average fluid velocity, and μ is the dynamic viscosity of the fluid.

[0046] Reference will now be made to the accompanying drawings, which depict one or more aspects described in this disclosure. However, it should be understood that other aspects not depicted in the drawings fall within the scope of this disclosure. Like numbers used in the figures refer to like components, steps, etc. However, it should be understood that using a reference numeral to refer to an element in a given figure is not intended to limit the element in another figure labeled with the same reference numeral. Additionally, using different reference numerals to refer to elements in different figures is not intended to indicate that the differently-referred elements cannot be the same or similar.

[0047] Figure 1 is a conceptual diagram showing an example of a fluid system 100 that includes a particle separation element 102 configured to receive a fluid stream from a fluid source 104. The fluid system 100 can be any suitable type of system that can benefit from using the particle separation element 102, such as an engine fuel system, a bulk fuel system, or a hydraulic system. The fluid source 104 can be configured to contain a fluid that can contain particles. The particle separation element 102 can be used as a filter to facilitate the removal of particles within a specific size range from the fluid. For example, particles that are considered contaminants or waste can be removed. Additionally or alternatively, the particle separation element 102 can be used to facilitate the sorting of particles of different sizes. The sorting of particles of different sizes can allow the fluid system 100 to determine how many particles are within different size ranges.

[0048] The particle separation element 102 can be fluidly coupled between the fluid source 104 and a fluid destination, such as optional fluid destinations 106, 108. The particle separation element 102 can be positioned downstream of the fluid source 104. The particle separation element 102 can be positioned upstream of the fluid destinations 106, 108. The fluid destination 106 can be a component of the fluid system 100 that stores, uses, or consumes the fluid, such as fuel consumed by an engine. The fluid destination 108 can be a component of the fluid system 100 that uses the fluid and returns the fluid to the fluid source 104, such as hydraulic fluid used in a hydraulic piston. The particle separation element 102 can remove particles within a specific size range from the fluid before providing the fluid to one of the fluid destinations 106, 108.

[0049] The particle separation element 102 can include any suitable components that can be used to remove particles from the fluid or sort particles in the fluid. In some embodiments, the particle separation element 102 includes a hydroseparation element. Generally, the particle separation element 102 (which can include a hydroseparation element) will not become loaded with particles and will not change performance over time or require regular replacement.

[0050] The hydraulic separation element may include one or more hydrocyclones. In some embodiments, the hydrocyclones are arranged in parallel. The channel length and arrangement of the hydrocyclones can be designed to provide a target pressure drop.

[0051] In some embodiments, the particle separation element 102 includes a flow path selection element. The flow path selection element may be disposed in the outlet of the particle separation element 102. The flow path selection element may include one or more valves or solenoids to divert the fluid flow.

[0052] Generally, the particle separation element 102 includes an outlet having at least two different branches. The fluid flow can be split between the different branches. In some embodiments, using a hydraulic separation element, all particles within a particular size range can be concentrated into one of the branches. Each branch may be associated with a different size range of particles (see Figures 9 to 10 ).

[0053] Each branch may point to a different fluid destination or be in fluid communication with a different fluid destination. In some embodiments, one branch may be directed to the fluid destination 106 and the other branch may be directed to the fluid destination 108.

[0054] The fluid pump 114 can be used to control the flow rate of the fluid through the particle separation element 102. The fluid pump 114 can be positioned relative to the particle separation element 102 at any suitable location (such as upstream, downstream, or integrated with the particle separation element) to facilitate the control of the flow rate. In the illustrated embodiment, the fluid pump 114 is positioned upstream of the particle separation element 102.

[0055] The particle sensor 112 can be used to detect any particles in the fluid flow. The particle sensor 112 can be positioned relative to the particle separation element 102 at any suitable location (such as upstream, downstream, or integrated with the particle separation element) to facilitate the detection of certain particles. In some embodiments, the particle sensor 112 can be positioned between the inlet and the outlet of the particle separation element 102. The particle sensor 112 can use any suitable type of mechanism to detect particles in the fluid. For example, the particle sensor 112 can include or be an optical-based particle sensor 200 ( Figure 6 ) or a capacitance-based sensor.

[0056] The microfluidic sensing element 116 can be used to sense particles of different sizes from one or more branches of the branches of the particle separation element 102. The microfluidic sensing element 116 is shown positioned downstream of the particle separation element 102. In some embodiments, the microfluidic sensing element 116 can be described as part of the particle separation element 102. The microfluidic sensing element 116 can include one or more microfluidic sensing channels. In some embodiments, the microfluidic sensing channels are arranged in parallel. The channel length and arrangement of the microfluidic sensing channels can be designed to provide a target pressure drop and particle concentration.

[0057] Each microfluidic channel can be fluidly coupled to one of the branches of the particle separation element 102. The microfluidic sensing element 116 can also include one or more particle sensors 112 to detect particles of different sizes that have been sorted by the particle separation element 102. The microfluidic sensing element 116 can also be used to determine whether the particle separation element 102 has successfully removed some or all of the particles within a specific size range. The microfluidic sensing element 116 can also include a flow path selection element. The flow path selection element can be used to facilitate the removal of particles within a specific size range.

[0058] The fluid subsystem 120 can be defined to include one or more of the following: the particle separation element 102, the fluid pump 114, the microfluidic sensing element 116, and the controller 110. The controller 110 can be used to facilitate the various functions of the fluid subsystem 120 described herein.

[0059] Various configurations of the fluid system 100 are envisioned. Further configurations of the fluid system 100 and non-limiting examples of the various components are shown and described in more detail herein.

[0060] In one example that can be described as a kidney-shaped loop filter (not shown), the fluid pump 114 can be used to provide a fluid flow from the fluid source 104 or source reservoir through the particle separation element 102, which can include a hydroseparator element that returns the main stream through the filter back to the fluid source 104. An industrial system with a liquid fluid can use a kidney-shaped loop filtration system to remove particles. The particle separation element 102 can be used between the fluid pump 114 and the filter. The particle separation element 102 can provide a main outlet flow to the fluid source 104 and return a secondary outlet flow containing certain particles back to the filter, which can agglomerate the particles and minimize the volume of fluid to be filtered, as well as reduce the surface velocity, which can reduce the filter pressure drop.

[0061] One or more components described herein (such as a controller, sensor, detector, or system) may include a processor, such as a central processing unit (CPU), a computer, a logic array, or other device capable of directing data into and out of the component. The processor may include one or more computing devices having memory, processing, and communication hardware. The processor may include circuitry for coupling the various components of the controller together or coupling the various components of the controller to other components operably coupled to the controller. The functions of the processor may be performed by hardware and / or as computer instructions on a non-transitory computer-readable storage medium.

[0062] The processor may include any one or more of a microprocessor, a microcontroller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), and / or equivalent discrete or integrated logic circuitry. In some examples, the processor may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, and / or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to the processor herein may be implemented as software, firmware, hardware, or any combination thereof.

[0063] In one or more embodiments, the functions of the processor may be implemented by using a computing device with one or more computer programs, which may include one or more processors and / or memory. The program code and / or logic described herein may be applied to input data / information to perform the functions described herein and generate the desired output data / information. The output data / information may be applied as input to one or more other devices and / or methods described herein or applied in a known manner. Given the above, it is apparent that the controller functions described herein may be implemented in any manner known to those skilled in the art.

[0064] Figure 2 is a conceptual diagram showing an example of a fluid system that may be used to process fuel on a machine using a particle separation element 102. The particle separation element 102 (which may include a hydroseparator element) may be used on a fluid system 120 (such as an engine fuel system) and may replace the use of a primary filter along the main fuel line 122. In an engine fuel system, a lift pump draws fluid from a fuel tank and pushes it to a high pressure common rail. Some fuel may return from the fuel injector system to the fuel tank through a fuel return line 128.

[0065] As shown, a fluid pump 114 (such as a fuel pump or a lift pump) can be used to provide a fluid flow, such as fuel, from a fluid source 104 (such as a fuel tank) that flows through a particle separation element 102 and through a main fuel line 122. The particle separation element 102 can use a first flow branch 123 to provide a main outlet flow along the main fuel line 122 to a fluid destination 106 (such as a fuel injector system that can include a high-pressure common rail), and return a secondary outlet flow containing certain particles along a second flow branch 124 to the fluid source 104. Non-limiting examples of particles include dirt and micro water droplets.

[0066] The particle separation element 102 can be positioned upstream or downstream of the fluid pump 114. In the illustrated embodiment, the particle separation element 102 is positioned downstream of the fluid pump 114. A filter 126 can be positioned along the main fuel line 122 downstream of the particle separation element 102. The filter 126 or the fuel filter can be configured to filter particles from gasoline or diesel fuel. The fluid system 120 can also include a fuel return line 128 from the fluid destination 106 to the fluid source 104. In other embodiments (not shown), the filter 126 can be positioned along the second flow branch 124, or another filter 126 can also be positioned along the second flow branch, and the filter can filter particles at a lower flow rate and pressure drop.

[0067] The particle separation element 102 can be configured to remove particles having a diameter that exceeds or is greater than a specific threshold size from the main fuel line 122, while the fluid pump 114 provides fuel for engine operation at a specific flow rate and delivers such particles to the second flow branch 124. Non-limiting examples of the specific threshold size include 1, 2, 5, 10, 15, or 20 microns.

[0068] The outlet of the particle separation element 102 can be described as having two outlet streams: a "clean" outlet stream along a first flow branch 123 to the main fuel line 122, and a "dirty" outlet stream along a second flow branch 124. The clean outlet stream may be substantially free of particles above a threshold size. The clean outlet stream can be conveyed to a filter 126 and ultimately to a fluid destination 106, which is shown as the high-pressure common rail of a fuel injector system. The dirty outlet stream can contain most of the particles above a critical size. The dirty stream can be conveyed back to the fluid source 104 (shown as a fuel tank). In other embodiments, the dirty outlet stream can be combined with a fuel return line from a high-pressure common rail system. In other words, the second flow branch 124 can be fluidly coupled to the fuel return line 128 before returning to the fluid source 104. The particle separation element 102 can have a mechanism for controlling the dirty outlet stream along the second flow branch 124, such as a valve (not shown), to facilitate operation as the filter pressure limit increases over time due to the loading of the filter 126 along the first flow branch 123.

[0069] Figure 3 is a conceptual diagram showing an example of a fluid system that can be used to process bulk fuel using a particle separation element 102. The particle separation element 102 (which can include a hydroseparator element) can be used on a fluid system 140, such as a fuel dispensing station, and can be used to remove particles before fuel is provided to a fluid destination 106, such as a vehicle.

[0070] As shown, a fluid pump 114 can be used to provide a fluid flow, such as fuel, from a fluid source 104, such as a bulk fuel storage tank, through the particle separation element 102 to the main fuel line 142. The particle separation element 102 can use a first flow branch 143 to provide a main outlet stream along the main fuel line 142 to a fluid destination 106, such as a vehicle, and a secondary outlet stream containing certain particles for return along a second flow branch 144 to the fluid source 104 or conveyance to a fluid destination 108, such as a secondary storage tank. Non-limiting examples of particles include dirt and micro water droplets.

[0071] The particulate separation element 102 can be positioned upstream or downstream of the fluid pump 114. In the illustrated embodiment, the particulate separation element 102 is positioned downstream of the fluid pump 114. The filter 146 can be positioned downstream of the particulate separation element 102 along the main fuel line 122. The filter 146 or the fuel filter can be configured to filter particulates from gasoline or diesel fuel. The fluid system 120 can also include a fuel return line 128 from the fluid destination 106 to the fluid source 104. In other embodiments (not shown), the filter 146 can be positioned along the second flow branch 144, or another filter 146 can also be positioned along the second flow branch, and the filter can filter particulates at a lower flow rate and pressure drop.

[0072] The particulate separation element 102 can be configured to remove particulates having a diameter greater than a specific threshold size from the main fuel line 122, while the fluid pump 114 provides fuel at a specific flow rate suitable for a fuel dispensing station and delivers such particulates to the second flow branch 144.

[0073] The outlet of the particulate separation element 102 can be described as having two outlet flows: a "clean" outlet flow along the first flow branch 143 to the main fuel line 142, and a "dirty" outlet flow along the second flow branch 144. The clean outlet flow may be substantially free of particulates larger than the threshold size. The clean outlet flow can be conveyed to the filter 126 and ultimately to the fluid destination 106, which is shown as a high-pressure common rail system. The dirty outlet flow can contain most of the particulates larger than the critical size. The dirty outlet flow can be conveyed back to the fluid source 104 (shown as a bulk fuel storage tank), or can be conveyed to the fluid destination 108 (shown as a separate tank for containing dirty or contaminated fuel). The particulate separation element 102 can have a mechanism for controlling the dirty outlet flow along the second flow branch 144, such as a valve (not shown), to facilitate operation when the filter pressure limit increases over time due to the load on the filter 146 along the first flow branch 143.

[0074] Figure 4 is a conceptual diagram showing an example of a fluid system that can be used to convey hydraulic fluid using the particulate separation element 102. The particulate separation element 102, which can include a hydroseparator element, can be used on a fluid system 160 (such as a hydraulic cylinder system) and can be used to remove particulates before providing the hydraulic fluid to a hydraulic component (such as an actuating cylinder) to protect the hydraulic component against particulates.

[0075] As shown, a fluid pump 114 (such as a hydraulic pump) can be used to provide a fluid flow from a fluid source 104 (such as a hydraulic fluid reservoir) through a particle separation element 102 to a main fluid line 162. The fluid source 104 can be in fluid communication with the inlet of the fluid pump 114. The particle separation element 102 can use a first flow branch 163 to provide a main outlet flow along the main fluid line 162 to a fluid destination 106 (such as a hydraulic component, which can include an actuator cylinder), and a secondary outlet flow containing certain particles, which is used to return to the fluid source 104 along a second flow branch 164. Non-limiting examples of particles include dirt, air bubbles, or micro water droplets. The fluid system 160 can also include a fluid return line 168 from the fluid destination 106 to the fluid source 104. Before returning to the fluid source 104, the second flow branch 164 can be fluidly coupled to the fluid return line 168.

[0076] The particle separation element 102 can be positioned upstream or downstream of the fluid pump 114. In the illustrated embodiment, the particle separation element 102 is positioned downstream of the fluid pump 114. A hydraulic fluid filter 166 can be positioned downstream of the particle separation element 102 along the second flow branch 164, the fluid return line 168, or both. As shown, the second flow branch 164 and the fluid return line 168 merge before reaching the filter 166. The filter 166 can be in fluid communication with the fluid source 104.

[0077] The outlet of the particle separation element 102 can be described as having two outlet flows: a "clean" outlet flow along the first flow branch 163 to the main fluid line 162, and a "dirty" outlet flow along the second flow branch 164. The clean outlet flow can continue to flow to the fluid destination 106, which is shown as a hydraulic component. The dirty outlet flow can be combined with the fluid return line 168, and before returning to the fluid source 104, the fluid return line will pass through the filter 166, and the fluid source is shown as a fluid reservoir. The particle separation element 102 can be designed to operate within a range of temperature, flow rate, and system configuration (such as the extension of a hydraulic cylinder).

[0078] Figure 5 is a conceptual diagram showing an example of a fluid system that can be used to degas hydraulic fluid using a particle separation element 102. The particle separation element 102, which can include a hydroseparator element, can be used on a fluid system 180 (such as a hydraulic cylinder system), and can be used to remove nucleated air bubbles before returning the hydraulic fluid to the fluid source 104 (such as a main hydraulic fluid reservoir) to protect the fluid destination 106 (such as a hydraulic component) from air bubbles.

[0079] As shown, a fluid pump 114 (such as a hydraulic fluid pump) can be used to provide a fluid flow from a fluid source 104 (such as a main hydraulic fluid reservoir) along a main fluid line 182 to a fluid destination 106 (such as a hydraulic component), which can include an actuator cylinder. A return fluid flow can be provided from the fluid destination 106 to a nucleation filter 169 to nucleate bubbles in the fluid along a fluid return line 188. A particle separation element 102 can be positioned downstream of the nucleation filter 169. The nucleation filter 169 can be in fluid communication with the inlet of the particle separation element 102 and the fluid destination 106. The particle separation element 102 can use a first flow branch 183 to provide a main outlet flow along the fluid return line 188 to the fluid source 104 and a secondary outlet flow (such as a settling reservoir or a charged oil collection volume) along a second flow branch 184 to a fluid destination 108, the secondary outlet flow containing certain particles. The fluid destination 108 can be in fluid communication with the fluid source 104 with a restricted flow to allow the charged hydraulic fluid to be collected and settled.

[0080] The fluid in the hydraulic fluid system 180 is pressurized by the fluid pump 114. High-pressure fluid can dissolve more air. When the fluid is depressurized in the fluid return line 188, the fluid may become supersaturated with air, which can cause the nucleation and formation of bubbles in the fluid flow. Before the fluid is drawn up again by the fluid pump 114, the bubbles may have been removed. Bubbles reaching the fluid pump 114 can cause cavitation, which can be loud and can damage the fluid pump. The nucleation filter 169 can be used to nucleate and grow bubbles. The fluid filled with bubbles can be conveyed through the particle separation element 102, which can include a hydroseparator. The bubbles may aggregate into the "charged return oil" outlet flow along the second flow branch 184. The charged return oil outlet flow can return to the fluid destination 108 or the settling reservoir in a volume that allows natural bubble settlement. The fluid destination 108 can be a separate compartment in the same container as the fluid destination 106. The "main return" (without bubbles) along the outlet flow is conveyed along the fluid return line 188 to the fluid destination 106 and can be immediately used by the fluid system 180.

[0081] Figure 6 is a conceptual diagram showing an example of an optical or light-based particle sensor 200, which can be used or serve as a particle sensor 112 ( Figure 1)。Generally, any suitable type of particle sensor can be used, including, for example, the particle sensor described in PCT Application No. PCT / US2019 / 034809 filed on May 31, 2019, which is incorporated herein by reference. When the particle sensor 200 is used to detect microdroplets of a fluid, the particle sensor 200 can be described as a microdroplet sensor. The particle sensor 200 can be operatively coupled to the controller 110 and optically coupled to the microfluidic channel 201, which can be a part of the hydroseparator of the particle separation element 102( Figure 1 ), or a part of the microfluidic sensing element 116( Figure 1 ).

[0082] As shown, the particle sensor 200 includes a light source 202, an aperture 204, and a light detector 206. The controller 110 can be operatively connected to the light detector 206 and can also be operatively connected to the light source 202.

[0083] The microfluidic channel 201 is configured to receive a flow of fluid 208. The microfluidic channel 201 can have any suitable cross-sectional shape, such as rectangular, circular, or oval. The particle sensor 200 can be configured to detect and characterize particles 210 in the flow of fluid 208 that may flow through the microfluidic channel 201, such as microdroplets, bubbles, dirt, metal.

[0084] The particles 210 can be dispersed in the fluid 208 in the microfluidic channel 201. For example, the particles 210 can be suspended in the fluid 208 in a separate phase or made of a different composition or material. In other words, the particles 210, which may be liquid, are not dissolved in the fluid 208. In one example, the particles 210 can include a fluid different from the fluid 208.

[0085] Generally, the size of the microfluidic channel 201 is set to receive one or more particles 210 at a time. In some embodiments, the cross-sectional area size of the microfluidic channel 201 is set to receive a particle 210 of a predetermined size at a time. In particular, the cross-sectional area size of the microfluidic channel 201 can be approximately the same as the cross-sectional area of the particle 210, which can facilitate counting one particle 210 at a time to facilitate accurate counting and sizing of the particles 210.

[0086] The cross-sectional area can be defined as orthogonal to the direction of fluid 208 flow. In other words, the cross-sectional area can be described as transverse to the longitudinal fluid 208 flow. The cross-sectional area can be defined as the channel height (or depth) multiplied by the channel width. Both the channel height and the channel width can be orthogonal to the direction of fluid 208 flow. In some embodiments, the channel depth is less than or equal to the channel width. When particles flow through the microfluidic channel 201, using a relatively shallow channel depth can prevent particles 210 from accumulating between the light source 202 and the light detector 206, or hiding from each other, which increases the chance of each particle being detected. light source

[0087] In the illustrated embodiment, the light source 202 is positioned outside the microfluidic channel 201. At least one light aperture 204 is positioned between the light source 202 and the light detector 206. In some embodiments, the light aperture 204 is positioned before the microfluidic channel 201, e.g., between the light source 202 and the microfluidic channel 201. In some embodiments, the light aperture 204 is positioned after the microfluidic channel 201, e.g., between the microfluidic channel 201 and the light detector 206.

[0088] The light source 202 is configured to direct light 212 through the light aperture 204 to form a light beam 214. The light beam 214 is directed through the microfluidic channel 201. At least for the path length of the light beam 214 through the microfluidic channel 201, the light beam 214 can be collimated or substantially collimated by the light aperture 204. The light beam 214 can define a light beam axis extending through the microfluidic channel 201. The walls of the microfluidic channel 201 can be formed of a light-transmissive material (at least for the light 212 provided by the light source 202).

[0089] The path where the light beam 214 intersects the microfluidic channel 201 defines a sensing region 216, which can also be described as a sensing volume, in which particles 210 can be detected. After the light beam 214 passes through the microfluidic channel 201, the light beam 214 is received by the light detector 206, which can be positioned outside the microfluidic channel 201. When particles 210 and fluid 208 are in the sensing region 216, the light detector 206 can be used to determine the light absorbance of the particles 210 and the fluid 208 with respect to the light beam 214 to detect the particles 210, determine the size of the particle, or otherwise characterize the particle.

[0090] As used herein, the term "path length" refers to the distance that light from the light source 202 travels in the fluid to be measured. In some embodiments, the path length can be approximately equal to the width or depth of the microfluidic channel 201. The path length can be small to increase the sensitivity to particles 210. In some embodiments, the path length is less than or equal to 2000, 1000, 500, 300, 250, 200, 150, or 100 microns. In one or more embodiments, the path length is less than or equal to 1000 microns.

[0091] The light source 202 is configured to produce light in a selected frequency band such that the particles 210 have a different light absorption rate than the fluid 208 in the selected frequency band. In one or more embodiments, for example, when the liquid is water and the fluid 208 is a hydrocarbon fluid, the particles 210 have a higher light absorption rate than the fluid 208. For example, in a fuel system application, the light source 202 can produce light 212 at least in the near-infrared (NIR) frequency band. In some embodiments, the NIR light 212 can include an emission peak in the range of 1400 to 1600 nanometers, or at least include frequencies within this range. In particular, the NIR light 212 can include an emission peak centered at or near 1550 nanometers. In some embodiments, the NIR light 212 can include an emission peak in the range of at least 900 to 1100 nanometers, or at least include frequencies within this range. In particular, the NIR light 212 can include an emission peak centered at or near 1000 nanometers.

[0092] The light source 202 can include any suitable type of light source capable of providing light 212 in the selected frequency band. In some embodiments, the light source 202 is a light-emitting diode (LED). The LED light source 202 can be a low-power LED. In some embodiments, the LED light source emits omnidirectionally or in all directions from the light-emitting junction. In some embodiments, the LED light source emits primarily in one direction. In some embodiments, the light source 202 can be paired with or include an optical fiber cable that directs the light into the microfluidic channel 201. The light aperture 204 can be used to allow a narrow light beam 214 to pass through the microfluidic channel 201, which can facilitate the elimination of noise or false signals, for example, due to scattering and reflection.

[0093] The light aperture 204 can be or include at least one opening in the aperture element 218. As used herein, "aperture" refers to an opening or void within the aperture element 218. The light aperture 204 can have a width sized relative to the microfluidic channel 201 and the light detector 206 to facilitate optimal sensitivity for detecting particles 210 in the fluid 208. In some embodiments, the width of the light aperture 204 is the same as or substantially the same as the channel width of the microfluidic channel 201.

[0094] Additionally or alternatively, the size of the aperture 204 can be set relative to a predetermined particle size of interest. For example, in some embodiments, the width of the aperture 204 can be designed to be less than or equal to 2, 3, 4, 5, 6, 7, 8, 9, or 10 times the particle size of interest. In some embodiments, the width of the aperture 204 can be designed to be greater than or equal to 1, 2, 3, 4, 5, 6, 7, 8, or 9 times the particle size of interest.

[0095] The aperture 204 can have any suitable geometry. In some embodiments, the aperture 204 has a circular or rounded shape, such as circular or oval. In some embodiments, the aperture 204 has a polygonal shape, such as triangular, square, trapezoidal, or rectangular. The aperture 204 can have a length that extends along the same direction as the flow of the fluid 208. In one or more embodiments, the length of the aperture 204 can be the same as or substantially the same as the width of the aperture 204. Light detector

[0096] The light detector 206 can be any suitable type of photodetector sensitive to a selected frequency band, which can be the NIR band. The light detector 206 is also configured to provide a signal representative of the amount of light remaining from the light beam 214 after passing through the microfluidic channel 201. In particular, the light detector 206 can be configured to generate an electrical signal, such as a current signal, a voltage signal, or a power signal, in response to receiving light within the selected frequency band. Non-limiting examples of photodetector types include indium gallium arsenide (InGaAs), germanium (Ge), or silicon (Si) photodiodes. For example, an InGaAs photodiode can be sensitive to light 212 in a band from 1100 to 1700 nanometers. A Ge photodiode can have a peak sensitivity at 1550 nanometers. An Si photodiode can be used for visible light. Controller

[0097] The controller 110 can be configured to detect, determine the size measurement of, or otherwise characterize one or more particles 210 dispersed in the flow of the fluid 208 based on the signal from the light detector 206. In some embodiments, the controller 110 can be configured to detect one particle 210 dispersed in the flow of the fluid 208 at a time, particularly a particle of a predetermined size.

[0098] Generally, when the particle 210 is a fluid, the particle can also be referred to as a droplet. When the particle 210 is a liquid, the signal can be used to determine the amount of liquid (e.g., water) (excluding the liquid dissolved in the fluid) per unit volume of the fluid 208 (e.g., hydrocarbon fluid).

[0099] In some embodiments, the controller 110 is configured to determine the particle rate through the sensing region 216. For example, a change in the absorbance rate detected based on the signal from the light detector 206 can indicate that particles 210 are entering or leaving the sensing region 216. Alternatively or additionally, the controller 110 can be configured to determine the particle size. In some embodiments, the controller 110 can determine the particle rate or the particle size based on at least one of the following: the amplitude of the pulses contained in the signal, the width of the pulses contained in the signal, a first threshold signal level for detecting the smallest size particles in the sensing region, a second threshold signal level for detecting particles that fill the sensing region, and the threshold signal level crossing rate. When the particles are a fluid, the controller 110 can determine the amount of particles 210 in the form of droplets in the fluid 208 per unit volume, such as the particle concentration, based on the particle rate, the particle size, or both. In some applications, such as non-engine applications, when the particle rate is regular or substantially regular, the particle rate can be used to estimate or determine the particle size or concentration.

[0100] In some embodiments, the controller 110 is further configured to determine the amount of particles 210 in the form of droplets in the fluid 208 per unit volume based on the droplet rate and the droplet size. The controller 110 can also be configured to determine the particle size based on the amplitude of the pulses contained in the signal data in response to the signal not crossing the second threshold signal level. The controller 110 can further be configured to determine the particle size based on the pulse width contained in the signal data in response to the signal crossing the second threshold signal level. Further, the controller 110 can be configured to determine the particle size based on the particle rate. Capacitance-based sensor

[0101] In other embodiments, a capacitance-based sensor (not shown) can be used as the particle sensor 112. To detect individual particles and evaluate fuel cleanliness, a capacitance sensor can be fabricated in the microfluidic channel 201 (e.g., near the outlet). The capacitance sensor can be used to detect particles 210, such as water or other droplets or metal particles. The capacitance sensor can include interdigitated electrodes to form a planar capacitor. The capacitance of this channel can be calculated by the following formula: where ε f is the dielectric constant of the fluid in the microfluidic channel, and l, w, and a are the geometric dimensions of the electrodes. When a particle passes through the microfluidic channel, the change in capacitance can be simplified to (approximately proportional to): where ε p is the dielectric constant of the particle, and A p is the area of the particle.

[0102] Capacitive sensors can be used to sense various particles in a fluid, for example, when the dielectric difference between the particulate material and the fluid is sufficient to generate a significant signal. Table 1 below shows the dielectric constants of various particles and fluids. A large difference in the dielectric constant between the particulate material and the background fluid may result in a large signal difference. Generally, in addition to the dielectric difference between the particles and the background fluid, the signal may also be related to the particle size. In the case where the size is known (or approximately known) (which can be determined by using the particle separation element 302 (see Figures 9 to 10 ), the signal can be used to determine the dielectric constant difference and, possibly, the contaminant material. Table 1

[0103] Figure 7 is a conceptual diagram showing an example of an arrangement 220 that uses the particle sensor 112 in combination with the microfluidic channel 221. The microfluidic channel 221 may include an inlet 222 and an outlet 224 that has at least a first flow branch 226 and a second flow branch 228.

[0104] A fluid stream 208 and particles 210 in the fluid stream can be received at the inlet 222. The particle sensor 112 positioned along the microfluidic channel 221 can detect any particles 210 to provide signal data indicative of a signal corresponding to the fluid 208 and the particles 210 dispersed in the fluid. The controller 110 can be operatively coupled to the particle sensor 112 to receive an indication that particles 210 have been detected.

[0105] The controller 110 can be operatively coupled to a flow path selection element 230 positioned along at least one of the flow branches 226, 228 of the outlet 224. In the illustrated embodiment, the flow path selection element 230 includes a single valve 232 that is positioned between the first flow branch 226 and the second flow branch 228 to selectively divert the fluid stream to one branch or the other. The controller 110 can be configured to control the flow path selection element to direct the fluid stream to the first flow branch 226, for example, until the particle sensor 112 in the microfluidic channel 221 detects a threshold level of particles 210. The controller 110 can also be configured to determine whether there is a threshold level of particles 210 in the microfluidic channel 221 based on the signal data from the particle sensor 112. In response to determining that there is a threshold level of particles 210 in the microfluidic channel 221, the controller 110 can control the flow path selection element 230 to direct the fluid stream to the second flow branch 228.

[0106] The threshold level of the particles 210 can be determined in any suitable manner. Non-limiting examples include detecting one or more particles above a threshold size, detecting a number of particles exceeding a threshold number, detecting a threshold rate (or frequency) of particles, or detecting a threshold concentration of particles in a fluid.

[0107] The controller 110 can also determine the flow rate of the fluid 208 in the microfluidic channel 221. The flow rate can be used to determine the appropriate time to control when the fluid routing element 230 directs the fluid to the second flow branch 228, and the duration for which the fluid routing element directs the fluid back to the first flow branch 226.

[0108] The flow routing element 230 can include one, two, or more valves 232, solenoids, or any other suitable mechanism for diverting the fluid 208. In some embodiments (not shown), the flow routing element 230 includes two valves 232, each positioned along one of the flow branches 226, 228. The valves 232 can be opened or closed alternately to allow the fluid 208 to flow through the first flow branch 226 or the second flow branch 228. Water Droplet Removal

[0109] In some embodiments, the arrangement 220 can be described as a water droplet removal system or a microfluidic water droplet diverter system that can be used to remove water droplets (such as particles 210) from a hydrocarbon fluid. The diverter system can include a microfluidic droplet diverter, or a flow routing element 230, and a particle sensor 112 (e.g., of an optical type or a capacitive type) that can detect individual water droplets in the microfluidic channel 221. In the case where the microfluidic channel 221 contains water droplets, the fluid can be diverted to a waste stream, such as the second flow branch 228, via a valve switch or other mechanism (such as the valve 232). The waste stream can be conveyed to a waste collection area, conveyed to a water removal filter (such as a barrier or coalescing filter), or returned to the main fuel tank. The time of fluid diversion can be determined based on the geometry of the microfluidic channel (such as the dimensions and length between the sensor and the diverter valve) and the flow rate. After the water droplets are conveyed into the waste stream, the diverter valve can be switched so that the fluid is conveyed to the main outlet, such as the first flow branch 226. The main outlet is considered to be clean (such as fuel without water droplets) and can be conveyed to a particle removal filter, a high-pressure common rail system, or other parts of the fuel system.

[0110] In another configuration, the microfluidic droplet splitter can include two valves. One valve can be in the main outlet channel, such as the first flow branch 226, and the other valve can be in the waste outlet channel or the second flow branch 228. The valves can be near the junction where the inlet flow channel, the waste outlet channel, and the main outlet channel meet, and are thus incorporated into the microfluidic device. Alternatively, the valves can be remote from the junction and independent of the microfluidic device (e.g., in a tube or pipe leaving the device). When the droplet sensor detects a droplet, the main outlet valve can close, and the waste water outlet valve can open.

[0111] The splitter system can include more than one microfluidic channel to increase the total throughput. The multiple channels can share or not share the same particle sensor 112. The channel containing the droplets can be detected by the sensor output specific to that channel (see Figures 11A to 11B ).

[0112] The splitter system can also be used with a fuel system having two parallel coalescing elements. When a water sensor located downstream of the first coalescing element detects water, one or more valves can switch the flow from the first coalescing element to the second coalescing element. This can allow the driver to change the filter at longer intervals or at more convenient times.

[0113] Figure 8 FIG. is a conceptual diagram showing another example of an arrangement 240 using a particle sensor 112 in combination with a microfluidic channel 241 of a hydroseparator 260, which can be described as a microfluidic separation channel. The microfluidic channel 241 can include an inlet 242 and an outlet 244 having at least a first flow branch 246 and a second flow branch 248. As shown, the microfluidic channel 241 of the hydroseparator 260 is curved. The curve can follow a circular shape. In other embodiments, the microfluidic channel 241 can be curved and have a multiple S-shaped configuration. Any suitable curved shape can be used to provide sufficient inertial forces to concentrate particles within a specific size range at a specific flow rate. The inlet 242 can be located at one end or an end region, and the outlet 244 can be located at the opposite end or end region.

[0114] The hydroseparator 260 can be designed such that at a predetermined flow rate of the fluid 208, the microfluidic channel 241 is configured to direct any particles 210 larger than a corresponding threshold size into the second flow branch 248, and direct any remaining particles into the first flow branch 246 and the second flow branch 248 of the outlet 224.

[0115] A fluid stream 208 and particles 210 in the fluid stream can be received at an inlet 242. A particle sensor 112 positioned along a microfluidic channel 241 can detect any particles 210 to provide signal data representative of a signal corresponding to the fluid 208 and the particles 210 dispersed in the fluid. A controller 110( Figure 1 ) can be operatively coupled to the particle sensor 112 to receive an indication that particles 210 have been detected.

[0116] The controller 110 can be operatively coupled to a fluid pump 114( Figure 1 ) that is in fluid communication with the microfluidic channel 241 of a hydroseparator 260. The fluid pump 114 can be configured to direct fluid through the microfluidic channel 241 of one or more hydroseparators 260. The controller 110 can be configured to control the fluid pump to direct fluid from the inlet 242 through a hydroseparation element to an outlet 244. The controller 110 can also be configured to determine whether a threshold level of particles 210 is present in the microfluidic channel 241 based on signal data from the particle sensor 112. In response to determining that a threshold level of particles 210 is present in the microfluidic channel 241, the controller 110 can control the fluid pump 114 to direct fluid through the microfluidic channel of the hydroseparator 260 at a predetermined flow rate of the fluid 208 to concentrate any particles above a corresponding threshold size into a second flow branch 248.

[0117] Particle sensors 112a,b can be positioned at any suitable location along the microfluidic channel 241. In some embodiments, the particle sensors 112a,b can be positioned between the inlet 242 and the outlet 244. In some embodiments, the particle sensor 112a can be positioned closer to the inlet 242. When closer to the inlet 242, particles 210 above a threshold size do not concentrate along the inner wall 262 of the hydroseparator 260. The particle sensor 112a can define a sensing region (shown schematically as a solid line) that covers most or all of the width of the microfluidic channel 241 from the inner wall 262 to the outer wall 264. When closer to the outlet 244, particles 210 above a threshold size may concentrate along the inner wall 262 of the hydroseparator 260. The particle sensor 112b positioned towards the outlet 244 can define a sensing region (shown schematically as a solid line) that covers some or less than half of the width of the microfluidic channel 241 from the inner wall 262 to the outer wall 264.

[0118] Typically, when a droplet is sensed, the arrangement 240 can alter the fluid flow to concentrate the droplet into the waste stream. The flow rate can be calibrated based on size information from the particle sensors 112a,b to remove droplets or particles of a specific size. The flow rate can be altered by a pressure pulse, a constriction, or a change in the flow path (such as opening or changing the valve position of one or more valves located at the outlet 244).

[0119] In some embodiments, the waste stream (such as the second flow branch 248) can be only a portion of the size of the overall flow stream. This can minimize the impact on the overall flow stream when removing droplets.

[0120] Figures 9 to 10 FIG. is a conceptual diagram showing another arrangement 300 in which the particle sensor 112 is used together with the particle separation element 302 and the microfluidic sensing element 116. The arrangement 300 can be used to sort particles 210 and count the number of particles in different size ranges. Although the two-stage separation element 302 is shown separating the particles into three size ranges, any suitable number (n) of stages can be used to separate the particles into different size ranges (n + 1 size ranges).

[0121] In the illustrated embodiment, the particle separation element 302 is configured to sort the particles 210 in the first size range, the second size range, and the third size range into a first outlet stream 304 (containing particles in the first size range, the second size range, and the third size range), a second outlet stream 306 (containing particles in the second size range and the third size range), and a third outlet stream 308 (containing particles in the third size range) for sensing by the microfluidic sensing element 116. The particle sensor 112 can be positioned along the microfluidic sensing element 116 to detect the number of particles in each outlet stream 304, 306, 308. The controller 110 ( Figure 1 ) can determine the number of particles associated with each size range based on the volume fraction associated with the flow branches of the particle separation element 302.

[0122] As can be seen from Figure 10 the particle separation element 302 can include at least a first hydroseparator 320 and a second hydroseparator 322. Each hydroseparator 320, 322 can define a curved microfluidic channel to separate particles of different size variations, which can be described as a microfluidic separation channel. The outlet of the first hydroseparator 320 can include a first flow branch 326 and a second flow branch 328. The outlet of the second hydroseparator 322 can include a first flow branch 330 and a second flow branch 332.

[0123] The second flow branch 328 of the first hydroseparator 320 can be configured to provide a first outlet stream 304. The second flow branch 332 of the second hydroseparator 322 can be configured to provide a second outlet stream 306. The first flow branch 330 of the second hydroseparator 322 can be configured to provide a third outlet stream 308. The first flow branch 326 of the first hydroseparator 320 can be in fluid communication with or fluidly coupled to the inlet of the second hydroseparator 322 to provide a fourth fluid stream 310.

[0124] The first hydroseparator 320 can be configured to concentrate all particles within a first size range into the second flow branch 328. The first size range can include any particles that exceed a first threshold size. Any remaining particles that do not exceed the first threshold size can be provided to both the first flow branch 326 and the second flow branch 328. The remaining particles can be considered to be evenly distributed. The ratio of the remaining particles provided to each branch 326, 328 can be determined based on the volume fractions associated with each branch 326, 328. Typically, the first flow branch 326 can receive a first portion, and the second flow branch 328 can receive a second portion of any remaining particles that do not exceed the first threshold size. As can be seen Figure 9 from this, the first outlet stream 304 from the second branch 328 includes particles within various size ranges. None of the other outlet streams 306, 308 contain particles that exceed the first threshold size.

[0125] The second hydroseparator 322 can receive the stream from the first branch 326, which includes a second portion of any remaining particles that do not exceed the first threshold size. The second hydroseparator 322 can be configured to concentrate all particles within a second size range into the second flow branch 332. The second size range can include any particles that exceed a second threshold size. Any remaining particles that do not exceed the second threshold size can be provided to both the first flow branch 330 and the second flow branch 332, and these particles can be only those within a third size range. The remaining particles can be considered to be evenly distributed. The ratio of the remaining particles provided to each branch 330, 332 can be determined based on the volume fractions associated with each branch 330, 332. Typically, the first flow branch 330 can receive a first portion, and the second flow branch 332 can receive a second portion of any remaining particles that do not exceed the second threshold size. As can be seen Figure 9 from this, the second outlet stream 306 includes particles that do not exceed the first threshold size in both particle size ranges, and the third outlet stream 308 includes only particles that do not exceed the second threshold size.

[0126] The microfluidic sensing element 116 can be in fluid communication with the particle separation element 302. The microfluidic sensing element 116 can include a plurality of microfluidic channels 340, which can be described as microfluidic sensing channels, each of which is in fluid communication with a different flow branch of the particle separation element 302. The microfluidic channels 340 can be arranged in parallel. In particular, each microfluidic channel 340 receives a different outlet flow 304, 306, 308. The particle sensor 112 can be positioned and configured to detect the number of particles flowing through each microfluidic channel 340.

[0127] The controller 110 can determine the number of particles in each size range by counting the number of particles in any size range in each of the outlet flows 304, 306, 308 in the microfluidic channels 340. For illustrative purposes, assuming a volume fraction of 1:1 between each pair of flow branches and the number of remaining particles (the number of particles not exceeding the particle threshold size) is evenly divided between the two branches, the number of particles in each outlet flow can be calculated as follows:

[0128] where n 1 is the first size range, n 2 is the second size range, n 3 is the third size range, d 1 is the first threshold size, d 2 is the second threshold size, c 1 is the number of particles counted in the first outlet flow 304, c 2 is the number of particles counted in the second outlet flow 306, and c 3 is the number of particles counted in the third outlet flow 308.

[0129] Generally, the inlet of the particle separation element 302 can receive randomly distributed particles 210. The particle separation element 302 can sort the particles 210 into different outlet flows 304, 306, 308. The outlet flows 304, 306, 308 can be received by the microfluidic sensing element 116. The particle sensor 112 can count the number of particles in each microfluidic channel 340 of the microfluidic sensing element 116 and determine the number of particles in each size range.

[0130] In some embodiments, the particle sensor 112 can include a detector that is aligned with each microfluidic channel 340 to count the number of particles in each channel. In other embodiments, the particle sensor 112 can use a shared detector across multiple channels to count the number of particles in each channel.

[0131] The arrangement 300 can be described as a microfluidic particle sensor that can be used to measure the fluid cleanliness level in liquid applications. In one example, the microfluidic particle sensor can be used in a diesel filtration system to measure fluid cleanliness. The sensor can be placed upstream, downstream, or as a bypass of the filter. The sensor can include a staging or particle separation element 302 that separates particles into streamlines based on, for example, ISO cleanliness codes. These streamlines can include particles between 4 and 6 microns in a first stream, particles between 6 and 14 microns in a second stream, and particles greater than 14 microns in a third stream. Particles smaller than 4 microns in size can be excluded from the count, or additional stages (equal to four stages) can be added to capture particles smaller than 4 microns, between 4 and 6 microns, between 6 and 14 microns, and greater than 14 microns. The microfluidic particle sensor can also be used in hydraulic or lubricating oil applications.

[0132] The sensor can be described as having two stages. The first stage can be described as a "separation stage" that concentrates particles into specific streamlines based on particle size, such as the particle separation element 302. The second stage can be described as a "sensing stage" that includes multiple sensing channels (such as the microfluidic sensing elements 116), where the streamlines containing specific particles are routed to different channels. Each channel has a particle sensor or particle counter. The design of the separation stage can determine the range of particle sizes entering each channel. By counting or otherwise detecting the particles in the sensing channels, the particle size distribution can be determined.

[0133] Once the particles have been concentrated into streamlines based on their particle size, these streamlines can be routed to different sensing channels (such as the microfluidic channels 340). Each sensing channel corresponds to a range of particle sizes (based on the design and performance of the separation stage). Each sensing channel can be associated with a particle sensor. The particle sensor can detect the passage of or count the particles in the sensing channel. The particle sensor can be optical (using light absorption, fluorescence, scattering, or other optical methods), electronic (using a capacitance sensor or impedance sensor), or magnetic. When the signal output of each channel is unique, the sensing channels can share a single particle sensor.

[0134] This microfluidic particle sensor that uses a passive particle concentration scheme upstream of the particle counter does not need to be calibrated when counting particles. This can allow for simplified manufacturing. The microfluidic particle sensor can also be designed to work on a range of different types of particles with different properties (such as electrical or magnetic properties). The microfluidic particle sensor can also count individual particles one by one instead of reading the bulk fluid, which can increase sensitivity. Using microfluidic channels can also minimize the effect of the background fluid or carrier fluid.

[0135] Figures 11A to 11Bis a conceptual diagram showing an example of a technique for using a shared photodetector, such as photodetector 206 ( Figure 6 ), to count the number of particles in multiple microfluidic channels 340a, 340b, 340c. The pore element 350 can be similar to the pore element 218 ( Figure 6 ), except that the pore element 350 includes a plurality of pores 204 aligned with the respective microfluidic channels 340a, 340b, 340c. Each set of pores 204 can define a unique spacing pattern along the corresponding microfluidic sensing channels 340a, 340b, 340c. The unique spacing pattern can also be described as a unique orifice pattern.

[0136] The controller 110 (see Figure 6 ) can be configured to determine signal data based on signals from the photodetector 206 and to determine whether a particle has passed through the sensing region 216 based on the signal data. The controller 110 can determine the unique spacing pattern associated with the particles passing through the sensing region 216 based on the signal data. In particular, particles passing through the microfluidic sensing channel 340a can provide first unique signal data 342a, particles passing through the microfluidic sensing channel 340b can provide second unique signal data 342b, and particles passing through the microfluidic sensing channel 340c can provide third unique signal data 342c. The signal processing or pattern recognition processing of the controller 110 can be configured to distinguish these unique patterns to identify the corresponding microfluidic sensing channels 340a, 340b, 340c and the number of particles in the corresponding microfluidic sensing channels.

[0137] Generally, the unique spacing pattern provides a different time profile for droplets moving through a particular microfluidic sensing channel 340a, 340b, 340c. In the illustrated embodiment, a series of holes are placed at different distances from each other such that droplets moving through the channel will give several signal dips and the time pattern of the dips is specific to the channel. Orifice patterns (such as orifice openings of different shapes) that produce different signal profiles can also be used to create a unique signal. The unique spacing and the unique shape can also be used together. If there are multiple droplets in the channel, a signal deconvolution algorithm can be used to distinguish the individual channels.

[0138] In some embodiments, a diffraction grating can also be used to control the light entering the channel. The diffraction grating can be in the channel or enclosed in the channel and direct the light path towards a specific detector in the detector array.

[0139] Although the present disclosure is not limited thereto, an understanding of various aspects of the present disclosure will be obtained through the discussion of specific examples and illustrative embodiments provided below, which provide particle separation to supplement or replace a filter. Various modifications of the examples and illustrative embodiments, as well as additional embodiments of the present disclosure, will be apparent herein.

[0140] Figure 12 FIG. 4 is a conceptual diagram showing an example of a fluid system 360 that can be used to remove particles using a particle separation element 102. The particle separation element 102 (which may include a hydroseparator element) can be used on the fluid system 360 along a main flow line 362.

[0141] As shown, a fluid pump 114 can be used to provide a fluid flow from a fluid source 104 through the particle separation element 102 to the main flow line 362. The particle separation element 102 can provide a main outlet flow using a first flow branch 363 and a secondary outlet flow using a second flow branch 364. The first flow branch 363 and the second flow branch 364 can recombine along the main flow line 362 upstream of a fluid destination 106, which can include the remainder of the system 360.

[0142] The secondary outlet flow can be provided to a filter 366 along the second flow branch 364 upstream of recombination with the main outlet flow. An optional filter 368 can be located, for example, along the first flow branch 363 upstream of recombination or along the main flow line 362 downstream of recombination.

[0143] The particle separation element 102 can be located upstream or downstream of the fluid pump 114. In the illustrated embodiment, the particle separation element 102 is located downstream of the fluid pump 114.

[0144] The particle separation element 102 can be configured to remove particles having a diameter greater than a specific threshold size from the main flow line 362 while the fluid pump 114 provides fluid at a specific flow rate.

[0145] The separator element 102 can be used to concentrate particles above a specific threshold size into a portion of the total fluid flow. The concentrated particle flow can be concentrated or directed into the secondary outlet flow along the second branch 364, which can be provided to a filter 366, which can be described as a dead-end filter, to remove particles. After passing through the filter 366, the fluid of the concentrated particle flow from the second flow branch 364 can be combined with the remaining fluid from the first flow branch 363 and conveyed to the remainder of the system (shown as fluid destination 106). Particles above a critical size can be mostly removed from the overall fluid provided to the fluid destination 106.

[0146] In system 360, only a portion of the total fluid flow is filtered by filter 366. In some embodiments, the aggregated particle flow provided to the second flow branch 364 can include less than 50% of the total fluid volume, less than 25% of the total fluid volume, or less than 10% of the total fluid volume. The flow rate through filter 366 may be lower than, for example, the flow rate in a system that does not use the particle separation element 102. The lower flow rate may result in a lower filter pressure drop and / or a longer filter life, or both a lower filter pressure drop and a longer filter life.

[0147] An additional filter 368 can be used to remove particles below a critical size, for example, along the "clean flow" line of the first flow branch 363 after the fluid streamlines are combined, or along the main flow pipeline 362. A flow meter or variable pressure device in the clean flow along the first flow branch 363 can be used to properly balance the flow rates between the two flows exiting the separator element 102.

[0148] The technique of coupling the separator element 102 to a filter can be used in a variety of applications, such as engine fuel, engine oil, engine hydraulic systems, and stationary hydraulic systems. This technique may be particularly useful in engine oil, engine hydraulic systems, or stationary hydraulic systems where the fluid is recirculated through a filter system. Example Equipment manufacturing

[0149] In Example 1, a hydroseparator was fabricated as a microfluidic device from polydimethylsiloxane (PDMS) using standard soft lithography techniques. Briefly, a photomask was prepared using DraftSight and printed at 20,000 dpi (CAD / Art Services, Inc.; Brandon, OR). An SU-8 mold was prepared using SU-8 2100 photoresist (MicroChem Corp.; Newton, MA). The process parameters are described in the SU-8 2100 data sheet provided by MicroChem Corp. PDMS (Sylguard 184; Dow Corning; 10:1 w / w base: curing agent) was poured onto the mold, degassed for 30 minutes, and cured overnight in an oven at 85 °C. After removing the PDMS from the wafer, inlet and outlet holes were punched using a biopsy needle. Particles and fibers in the PDMS were removed using transparent tape. The final device was prepared by plasma bonding the PDMS to a glass slide at 800 microns (mTorr) for 1 minute using a Harrick Plasma cleaner. The finished device was placed on a hot plate at approximately 100 °C for 15 minutes. The device was designed with a constant radius of curvature, channel width, and channel depth. Particle imaging

[0150] In Example 2, fluorescent particles were suspended in deionized water for testing (Table 1). Particles of 2, 10, and 20 microns (μm) were provided as aqueous suspensions. These samples were diluted and tested directly.

[0151] Particles of 25 μm and 30 μm were provided in powder form. These samples had sodium dodecyl sulfate surfactant (SDS) added in deionized water to prepare the test solution.

[0152] A typical mixture contained 50 mg of particles, 100 mg of SDS, and 500 mL of deionized water. A laser diffraction particle size analyzer (Beckman-Coulter LS-320) was used to determine the particle size distribution.

[0153] The particles were fed into the hydroseparator prepared according to Example 1 using a pressure-driven flow system (ElveFlow OB1-Mk3; Elvesys, Paris, France). The system included an in-line flow meter for real-time measurement of the flow rate (Elveflow FS4 (0 - 1 mL / min) or FS5 (0.2 - 5 mL / min); Elvesys, Inc.; Paris, France). The flow rate could be controlled by pressure or flow rate within the ESI software package.

[0154] An Olympus IX-73 inverted microscope (Olympus LifeScience; Waltham, MA, USA) combined with a mercury vapor short arc lamp (U-HGLGPS, Olympus Life Science; Waltham, MA, USA) was used to optically measure the particle concentration within the hydroseparator. A fluorescence filter cube was selected to match the absorption and emission characteristics of the fluorescent particles. Images were taken with a 10x objective lens. Using MicroManager (version 1.4; https: / / micro-manager.org / wiki / Micro-Manager ) Images were captured using a Prime BSI sCMOS camera (Teledyne Photometrics; Tucson, AZ). Table 2: Fluorescent Particle Characteristics

[0155] Before injecting the particles, each hydroseparator was pressure-flow calibrated using deionized water (DI) to calibrate the unreliable flow meter readings for the particle-containing solution. The data was fit to a second-order polynomial and used to determine the operating pressure for the desired experimental flow rate.

[0156] During the particle experiment, the system pressure was controlled and pressure-flow data were recorded. If the pressure-flow data indicated attenuation within the experimental time range, it was assumed that the particles were collected somewhere in the device and the data were not recorded.

[0157] After the experiment, the device was cut in half and the channel depth was optically measured on a Keyence VHX digital microscope (Keyence; Itasca, Illinois).

[0158] Once the pressure-flow relationship of the device was calibrated, experiments could be conducted using a single fluorescent particle solution at a constant Dean number or flow rate. Fluorescent images were taken at different angles through the device to measure the particle concentration as a function of length (L = αR c , where α is the angular radian through the device and R is the radius of curvature measured on the inner wall). These angles were defined around the circular shape of each hydroseparator as shown, for example, Figure 14 . Figure 14 is a conceptual diagram showing the relative positions of the angles around the hydroseparator 400 at the inlet 10° (A), 180° (B), 270° (C), and the outlet 350° (D). The cMOS camera integration time was set to maximize the signal difference without saturating any pixels.

[0159] Image analysis in the open-source software ImageJ was used to determine the degree of particle concentration. The pixel intensity of the channel was measured at each imaging position of the device. It was assumed that the pixel intensity was proportional to the average particle concentration. The position of particle concentration was determined based on the outlet image (340° or 350°). For each image, the concentration percentage was determined as the ratio of the integrated pixel intensity of the concentrated area to the integrated pixel intensity of the entire channel, as follows:

[0160] Figure 13A shows a representative image from the device inlet 380 at 10 degrees. Figure 13B shows a representative image from the device outlet 382 at 350 degrees. Figure 13C is Figure 13A a graph 390 of the pixel intensity of the channel marked by the line 384 in Figure 13D is Figure 13B a graph 392 of the pixel intensity of the channel marked by the line 386 in Focused study: same equipment, different Dean numbers (140 μm depth: 25 μm particles)

[0161] In Example 3, 25-μm particles are concentrated in a hydrocyclone at two Dean numbers (channel width: 500 μm, channel depth: 140 μm, radius of curvature: 20 mm). Figure 15 Chart 410 shows the concentration percentage versus channel length data at a Dean number of 15 and a pressure of 1010 mbar (3.97 mL / min). Chart 410 shows three different regions: an initial region 412 where the particles are not concentrated, a region 414 where the particles are concentrated, and a region 416 where the particles are fully concentrated.

[0162] At the device inlet, the concentration of the particles is approximately 35%. In the first 14 mm of the channel length, the amount of concentration does not increase, which may be due to shear lift causing the particles to migrate from the center of the channel to the edge of the channel. This region 412 of the device can be described as the particle migration region and has a length L 0 . This length may depend on the particle size, fluid properties, and flow rate.

[0163] After the particle migration region, the percentage of concentrated particles can increase linearly with respect to the channel length. This region 414 of the device can be described as the linear concentration region. The slope of the linear fit can be described as the linear concentration rate (r f ). The percentage of concentrated particles increases linearly overall until a maximum value is reached.

[0164] Once the maximum value of particle concentration is reached, the particle concentration may remain approximately constant. This region 416 of the device can be described as the fully concentrated region. In this example, the maximum concentration percentage (f m ) in the fully concentrated region is shown as approximately 90% (i.e., 90% of the particles are concentrated).

[0165] The length of the hydrocyclone that can be used to achieve a target concentration percentage can be described as: where L D is the length of the hydrocyclone channel required to achieve the target concentration percentage, L 0 is the length of the particle migration region, r f is the linear concentration rate, f 0 is the particle concentration percentage at the inlet (and during the particle migration region 414), and f t is the target concentration percentage. This equation can be used specifically when f 0 < f t < f m .

[0166] Table 3 shows the data from a focused experiment using the same device at different Dean numbers. The length of the particle migration region and the length required to achieve 90% focusing are similar and almost identical. Table 3: Focusing data for experiments using the same device at different Dean numbers Experiments with the same Dean number and different equipment (104 μm depth: 30 μm particles) In Example 4, an experiment similar to Example 3 was conducted using approximately the same Dean number but on devices with two different radii of curvature. Particles of 30 μm were used. The experimental results are shown in Table 4. For the device with a smaller radius of curvature, the length of the particle migration region is shorter. Additionally, for the device with a smaller radius of curvature, the linear focusing rate is higher. Based on these results, for example, for a device with a smaller radius of curvature, the length required to focus the particles to 50% is shorter. Table 4: Focusing data for experiments using the same Dean number but different devices

[0167] Generally, compared to a device with a larger radius of curvature, a device with a smaller radius of curvature can reach the target Dean number at a lower flow rate. When comparing the pressure drop required to focus the particles, a smaller radius of curvature may result in a shorter channel and a lower flow rate, which may have a greater impact on the pressure drop.

[0168] As an example, based on the data in Table 4 and the experimental pressure applied, the pressure drop associated with a hydroseparator designed to focus 50% of the particles is calculated by the following equation:

[0169] where, P app is the pressure applied in the experiment, L D is the length required to achieve 50% focusing (Table 4), R c is the radius of curvature of the device (Table 4), and the term describes the experimental device design in which the device only covers an arc length of 350° to allow for an inlet port and an outlet port. The calculated pressure drop is shown in Table 4. The device with a smaller radius of curvature is used to focus the particles at a much lower pressure drop.

[0170] Length of the linear focused region

[0171] Recently, it has been found that the length of the linear focusing region required to achieve maximum particle focusing (85% - 95% particle focusing) can be described by the following relationship:

[0172] where, Re is the Reynolds number, De is the Dean number, DH is the hydraulic diameter of the hydroseparator, w is the channel width, and R c is the radius of curvature of the hydroseparator. More specifically, the relationship is as follows:

[0173] In addition, for a specific particle size, the length of the linear focusing region required to achieve maximum particle concentration can be described by the following relationship:

[0174] where a is the particle diameter. The particle diameter can be the equivalent spherical diameter of particles with a sphericity greater than 0.5. For particles with a diameter greater than 8% of the channel hydraulic diameter and less than or equal to 50% of the channel height, this equation can predict the length of the linear focusing region.

[0175] The total length of the hydroseparator can be determined or calculated as: L D = L 0 + L f (Equation 13)

[0176] This equation can be used to calculate the minimum hydroseparator channel length required to achieve maximum particle concentration for various applications. Experimental results show that the length range of the particle migration region L 0 is 0% to 29% of the total length of the hydroseparator L D required to achieve maximum particle concentration. Further, the data shows that the length range of the particle migration region L 0 is 0% to 40% of the length of the linear focusing region L f . Thus, the hydroseparator channel length L D can be greater than or equal to the length of the linear focusing region L f to achieve maximum particle concentration. The hydroseparator channel length L D can be no more than 40% greater than the length of the linear focusing region L f to achieve particle concentration balanced with minimizing the pressure drop across the channel. Exemplary embodiments

[0177] Some embodiments relate to hydroseparators.

[0178] In Embodiment A1, a system includes: A hydroseparation element including one or more hydroseparators, each hydroseparator defining a curved microfluidic channel in fluid communication, each microfluidic channel defining: An inlet configured to receive a fluid and particles dispersed in the fluid, wherein the particles have a different composition than the fluid, and An outlet that includes a first flow branch and a second flow branch, wherein, at a predetermined flow rate, each microfluidic channel is configured to direct any particles that exceed a corresponding threshold size into the second flow branch and to direct any remaining particles into both the first and second flow branches; A particle sensor positioned along one or more of the hydrocyclones, the particle sensor being configured to provide signal data representative of a signal corresponding to the fluid and particles in the fluid; and A controller operably coupled to the particle sensor to receive the signal data and operably coupled to a fluid pump in fluid communication with the hydroseparation element, the controller being configured to: Control the fluid pump to direct fluid through the hydroseparation element, Based on the signal data from the particle sensor, determine whether a threshold level of particles is present in the at least one microfluidic channel, and In response to determining that a threshold level of particles is present in the at least one microfluidic channel, control the flow rate through the hydroseparation element to direct fluid through the hydroseparation element at the predetermined flow rate so as to concentrate any particles that exceed a corresponding threshold size into the second flow branch of the at least one microfluidic channel.

[0179] In embodiment A2, a system includes the system according to embodiment A1, wherein the particle sensor includes: A light source configured to direct a beam of a certain frequency band along a path through at least one of the hydrocyclones, wherein the frequency band is selected such that the particles and the fluid have a more different light absorption rate; An aperture element that defines a light aperture positioned in the path of the beam from the light source; and A light detector positioned to receive the beam in a sensing area after the beam has passed through the at least one hydrocyclone and the light aperture, the light detector being configured to provide signal data representative of the amount of light of the frequency band remaining after passing through the at least one hydrocyclone.

[0180] In embodiment A3, a system includes the system according to embodiment A1, wherein the particle sensor includes a capacitance sensor.

[0181] In embodiment A4, a system includes the system according to any of the foregoing A embodiments, the system further including a source reservoir in fluid communication with the inlet and the second flow branch, wherein the fluid and particles can be pumped from the source reservoir to the hydroseparation element and selectively returned to the source reservoir through the second flow branch.

[0182] Some embodiments relate to particle splitters.

[0183] In Example B1, a system includes: A particle separation element, the particle separation element including: One or more microfluidic channels in parallel fluid communication, each microfluidic channel defining: An inlet configured to receive a fluid and particles dispersed in the fluid, wherein the particles have a different composition than the fluid, and An outlet, the outlet including a first flow branch and a second flow branch; A flow path selection element positioned along at least one flow branch of at least one outlet; A particle sensor positioned along one or more microfluidic channels, the particle sensor configured to provide signal data representative of a signal corresponding to the fluid and the particles dispersed in the fluid; and A controller operatively coupled to at least one flow path selection element and operatively coupled to the particle sensor to receive the signal data, the controller configured to: Control the flow path selection element to direct a fluid flow to the first flow branch of at least one outlet of the at least one microfluidic channel, Based on the signal data from the particle sensor, determine whether a threshold level of particles is present in the at least one microfluidic channel, and In response to determining that the threshold level of particles is present in the at least one microfluidic channel, control the flow path selection element to direct the fluid flow to the second flow branch of the at least one microfluidic channel.

[0184] In Example B2, a system includes the system according to Example B1, wherein the particle separation element includes a hydroseparator element, the hydroseparator element including one or more hydroseparators, the one or more hydroseparators including one or more microfluidic channels, wherein each microfluidic channel is curved.

[0185] In Example B3, a system includes the system according to Example B1 or B2, wherein the particle sensor includes: A light source configured to direct a beam of a certain frequency band along a path through at least one microfluidic channel, wherein the frequency band is selected such that the particles and the fluid have more different light absorption rates; A hole element defining a light hole positioned in the path of the beam from the light source; and A photodetector is positioned to receive the light beam in a sensing region after the light beam passes through the at least one microfluidic channel and the light aperture, and the photodetector is configured to provide signal data representing the amount of light in the frequency band remaining after passing through the at least one microfluidic channel.

[0186] In Embodiment B4, a system includes the system according to Embodiment B1 or B2, wherein the particle sensor includes a capacitance sensor.

[0187] In Embodiment B5, a system includes the system according to any of the foregoing B embodiments, and the system further includes a source reservoir in fluid communication with the inlet and the second flow branch, wherein fluid and particles can be pumped from the source reservoir to the hydroseparation element and selectively back to the source reservoir through the second flow branch.

[0188] Some embodiments relate to particle sorters.

[0189] In Embodiment C1, a system includes: A hydroseparation element including a plurality of hydroseparators in series fluid communication, the plurality of hydroseparators including at least a first hydroseparator and a second hydroseparator, each hydroseparator defining a curved microfluidic separation channel to separate particles in different size ranges, each microfluidic separation channel defining: An inlet configured to receive a fluid containing particles, and An outlet including a first flow branch and a second flow branch, wherein at a specific flow rate, each microfluidic separation channel is configured to direct any particles exceeding a corresponding threshold size into the second flow branch and direct any remaining particles into the first flow branch and the second flow branch, wherein the first flow branch of the first hydroseparator is in fluid communication with the inlet of the second hydroseparator; and A microfluidic sensing element in fluid communication with the hydroseparation element, the microfluidic sensing element including a plurality of microfluidic sensing channels, each microfluidic sensing channel in fluid communication with a different flow branch of the hydroseparation element, wherein the plurality of microfluidic sensing channels at least includes: A first microfluidic sensing channel in fluid communication with the second flow branch of the first hydroseparator to receive any particles exceeding a first threshold size, and A second microfluidic sensing channel in fluid communication with the second flow branch of the second hydroseparator to receive any particles exceeding a second threshold size, wherein the first threshold size is greater than the second threshold size.

[0190] In Example C2, a system includes the system according to Example C1, wherein the plurality of microfluidic separation channels include a third hydraulic separator in fluid communication with a first flow branch of a second hydraulic separator.

[0191] In Example C3, a system includes the system according to Example C1 or C2, further comprising: A particle sensor positioned along the plurality of microfluidic sensing channels, the particle sensor being configured to provide signal data representative of a signal corresponding to particles in the fluid; and A controller operably coupled to the particle sensor to receive the signal data, the controller being configured to determine the number of particles associated with each size range based on the signal data based on the volume fraction associated with the flow branch.

[0192] In Example C4, a system includes the system according to Example C3, wherein at least one microfluidic separation channel includes an outlet that includes a first outlet branch and a second outlet branch, further comprising at least one flow path selection element positioned at the outlet of the at least one microfluidic sensing channel, wherein the controller is operably coupled to the at least one flow path selection element and further configured to control the flow path selection element to direct the fluid flow to the second outlet branch in response to detecting particles in the corresponding microfluidic sensing channel.

[0193] In Example C5, a system includes the system according to Example C3 or C4, wherein the particle sensor includes a capacitance sensor.

[0194] In Example C6, a system includes the system according to Example C3 or C4, wherein the particle sensor includes: A light source configured to direct a beam of a certain frequency band along a path through at least one microfluidic sensing channel, wherein the frequency band is selected such that the particles and the fluid have a more different light absorption rate; An aperture element defining a light aperture positioned in the path of the beam from the light source; and A light detector positioned to receive the beam in a sensing region after the beam passes through the light aperture and the at least one microfluidic sensing channel, the light detector being configured to provide signal data representative of the amount of the light of the frequency band remaining after passing through the at least one microfluidic sensing channel.

[0195] In Example C7, a system includes the system according to Example C6, wherein the aperture element includes a plurality of optical apertures, the plurality of optical apertures including an optical aperture positioned in the path of a light beam from a light source, wherein the plurality of optical apertures includes a different set of optical apertures aligned with each microfluidic sensing channel, wherein each set of optical apertures defines a unique spacing pattern along the corresponding microfluidic sensing channel, and wherein a light detector is positioned to receive the light beam in a sensing region after the light beam passes through the plurality of optical apertures and the plurality of microfluidic sensing channels, and wherein a controller is configured to determine the number of particles associated with each size range based on the unique spacing pattern.

[0196] Some embodiments relate to orifice patterns.

[0197] In Example D1, a system includes: a plurality of microfluidic sensing channels, each microfluidic sensing channel configured to receive a fluid flow and particles dispersed in the fluid, wherein the particles have a different composition than the fluid; a light source configured to direct a light beam in a certain frequency band along a path through the plurality of microfluidic sensing channels, wherein the frequency band is selected such that the particles and the fluid have different light absorption rates; an aperture element defining a plurality of optical apertures, the plurality of optical apertures including different sets of optical apertures aligned with each microfluidic sensing channel, wherein each set of optical apertures defines a unique spacing pattern along the corresponding microfluidic sensing channel; a light detector positioned to receive the light beam in a sensing region after the light beam passes through the plurality of optical apertures of the aperture element and through the plurality of microfluidic sensing channels, the light detector configured to provide a signal representative of the amount of light in the frequency band remaining after passing through the plurality of microfluidic sensing channels; and a controller operably coupled to the light detector and configured to: determine signal data based on the signal from the light detector, determine whether a particle has passed through the sensing region based on the signal data, and determine a unique spacing pattern associated with the particles passing through the sensing region based on the signal data.

[0198] In Example D2, a system includes the system according to Example D1, wherein each microfluidic sensing channel is configured to receive particles in different size ranges, and the controller is further configured to determine the number of particles associated with each size range.

[0199] In Example D3, a system includes the system according to Example D1 or D2. The system further includes a hydroseparation element positioned upstream of a plurality of microfluidic sensing channels. The hydroseparation element includes a plurality of hydroseparators in serial fluid communication. The plurality of hydroseparators includes at least a first hydroseparator and a second hydroseparator. Each hydroseparator defines a curved microfluidic separation channel to separate particles in different size ranges. Each microfluidic separation channel defines: an inlet configured to receive a fluid and particles dispersed in the fluid, and an outlet including a first flow branch and a second flow branch, wherein, at a specific flow rate, each microfluidic separation channel is configured to direct any particles larger than a corresponding threshold size into the second flow branch and direct any remaining particles into the first flow branch and the second flow branch. The first flow branch of the first hydroseparator is in fluid communication with the inlet of the second hydroseparator.

[0200] In Example D4, a system includes the system according to Example D3, wherein the controller is further configured to determine the number of particles associated with each size range based on signal data based on the volume fraction associated with the flow branch.

[0201] In Example D5, a system includes the system according to Example D3 or D4, wherein the controller is operatively coupled to a fluid pump in fluid communication with the hydroseparation element. The controller is configured to control the fluid pump to direct fluid through the hydroseparation element at a specific flow rate.

[0202] In Example D6, a system includes the system according to any one of Examples D3 to D5, wherein at least one microfluidic sensing channel includes an outlet including a first outlet branch and a second outlet branch. The system further includes at least one flow path selection element positioned along the outlet of the at least one microfluidic sensing channel. The controller is operatively coupled to the at least one flow path selection element and is further configured to control the flow path selection element to direct the fluid flow into the second outlet branch in response to detecting particles in the corresponding microfluidic sensing channel.

[0203] Some embodiments relate to water droplet detection.

[0204] In Example E1, a system includes the system according to any one of Example A, any one of Example B, any one of Examples C4 to C8, or any one of Example D, wherein the particles include a second fluid different from the fluid.

[0205] In Example E2, a system includes the system according to Example E1, wherein the controller is further configured to determine the amount of the second fluid in the form of droplets in the fluid per unit volume based on the signal data.

[0206] In Example E3, a system includes the system according to Example E2, wherein the amount does not include the second fluid dissolved in the fluid.

[0207] In Example E4, a system includes the system according to any one of the foregoing E examples, wherein the controller is configured to determine the droplet rate or droplet size of one or more droplets of the second fluid dispersed in the fluid flow based on the signal data.

[0208] In Example E5, a system includes the system according to Example E4, wherein the controller is configured to determine the droplet rate or droplet size based on at least one of the following: The pulse amplitude included in the signal data, The pulse width included in the signal data, A first threshold signal level for detecting the smallest-sized droplets in the sensing region, A second threshold signal level for detecting the droplets filling the sensing region, and The threshold signal level crossing rate.

[0209] In Example E6, a system includes the system according to Example E5, wherein the controller is further configured to determine at least one of the following: Determine the amount of the second fluid in the form of droplets in the fluid per unit volume based on the droplet rate and droplet size; Determine the droplet size based on the amplitude of the pulse included in the signal data in response to the signal not crossing the second threshold signal level; Determine the droplet size based on the width of the pulse included in the signal data in response to the signal crossing the second threshold signal level; and Determine the droplet size based on the droplet rate.

[0210] In Example E7, a system includes the system according to any one of the foregoing E examples, wherein the fluid includes a hydrocarbon fluid and the second fluid includes water.

[0211] Some embodiments relate to an engine fuel system.

[0212] In Example F1, a system includes: A fuel line configured to deliver fuel to a fuel injector system; A hydraulic separation element, the hydraulic separation element including one or more hydraulic separators, each hydraulic separator defining a curved microfluidic channel to separate particles in the fuel, each microfluidic channel defining: An inlet in fluid communication with the fuel line to receive fuel, and An outlet, the outlet including a first flow branch in fluid communication with the fuel line to supply fuel to the fuel injector system, and a second flow branch for receiving particles within a specific size range.

[0213] In Embodiment F2, a system includes the system according to Embodiment F1, wherein the particles include micro water droplets dispersed in the fuel.

[0214] In Embodiment F3, a system includes the system according to Embodiment F1 or F2, the system further including a fuel tank in fluid communication with each inlet and in fluid communication with each second flow branch.

[0215] In Embodiment F4, a system includes the system according to any of the foregoing F embodiments, the system further including a fuel filter configured to filter particles from gasoline or diesel fuel located along the fuel line.

[0216] In Embodiment F5, a system includes the system according to any of the foregoing F embodiments, the system further including a fuel pump in fluid communication with the fuel line, wherein the fuel pump is configured to supply a fuel flow along the fuel line to the fuel injector system, wherein the fuel injector system includes a high-pressure common rail.

[0217] Some embodiments relate to bulk fuel systems.

[0218] In Embodiment G1, a system includes: A fuel line configured to transport fuel from a bulk fuel storage tank to a vehicle fuel tank; A hydraulic separation element, the hydraulic separation element including one or more hydraulic separators, each hydraulic separator defining a curved microfluidic channel to separate particles in the fuel, each microfluidic channel defining: An inlet in fluid communication with the fuel line to receive fuel, and An outlet, the outlet including a first flow branch in fluid communication with the fuel line to supply fuel to the vehicle fuel tank, and a second flow branch for receiving particles within a specific size range.

[0219] In Embodiment G2, a system includes the system according to Embodiment G1, the system further including a bulk fuel storage tank for storing fuel, the bulk fuel storage tank being in fluid communication with the inlet and optionally in fluid communication with the second flow branch.

[0220] In Embodiment G3, a system includes the system according to Embodiment G1 or G2, and the system further includes a secondary storage tank storing fuel that is in fluid communication with a second flow branch.

[0221] In Embodiment G4, a system includes the system according to any of the foregoing G embodiments, and the system further includes a fuel filter configured to filter particles from gasoline or diesel fuel located along a fuel pipeline.

[0222] In Embodiment G5, a system includes the system according to any of the foregoing G embodiments, and the system further includes a fuel pump in fluid communication with the fuel pipeline, wherein the fuel pump is configured to provide a fuel flow along the fuel pipeline to a fuel vehicle fuel tank.

[0223] Some embodiments relate to hydraulic particle filters.

[0224] In Embodiment H1, a system includes: A hydraulic fluid pipeline configured to convey hydraulic fluid from a hydraulic pump to a hydraulic component; A hydraulic separation element including one or more hydraulic separators, each hydraulic separator defining a curved microfluidic channel to separate particles in the hydraulic fluid, and each microfluidic channel defining: An inlet in fluid communication with the hydraulic fluid pipeline to receive hydraulic fluid from the hydraulic pump, and An outlet including a first flow branch in fluid communication with the hydraulic fluid pipeline to provide hydraulic fluid to the hydraulic component and a second flow branch for receiving particles within a specific size range.

[0225] In Embodiment H2, a system includes the system according to Embodiment H1, and further includes a hydraulic fluid filter for filtering particles from the hydraulic fluid, the hydraulic fluid filter being located along a hydraulic fluid return pipeline that is in fluid communication between the second flow branch and a hydraulic fluid reservoir, and the hydraulic fluid reservoir being in fluid communication with the inlet of the hydraulic pump.

[0226] Some embodiments relate to enhanced hydraulic degassing.

[0227] In Embodiment I1, a system includes: A hydraulic fluid return pipeline configured to convey hydraulic fluid from the hydraulic component to the hydraulic pump; A hydraulic separation element including one or more hydraulic separators, each hydraulic separator defining a curved microfluidic channel to separate particles in the hydraulic fluid, and each microfluidic channel defining: An inlet that is in fluid communication with a hydraulic fluid line to receive hydraulic fluid from a hydraulic pump, and An outlet that includes a first flow branch that is in fluid communication with the hydraulic fluid line to supply hydraulic fluid to the hydraulic pump, and a second flow branch that receives particles within a specific size range.

[0228] In Embodiment I2, a system includes the system according to Embodiment I1, wherein the particles include air bubbles.

[0229] In Embodiment I3, a system includes the system according to Embodiment I2, and the system further includes a nucleation filter configured to nucleate air bubbles in the hydraulic fluid that is in fluid communication between the hydraulic component and the inlet.

[0230] In Embodiment I4, a system includes the system according to Embodiment I3, and the system further includes: A main reservoir that is in fluid communication between the first flow branch and the hydraulic pump; and A settling reservoir that is in fluid communication between the second flow branch and the main reservoir.

[0231] Accordingly, various embodiments of systems and methods for separating particles in hydrocarbon fluids are disclosed. Although reference is made herein to the accompanying drawings that form a part of this disclosure, those of ordinary skill in the art will appreciate that many different adaptations and modifications of the embodiments described herein are within the scope of this disclosure or do not depart from the scope of this disclosure. For example, aspects of the embodiments described herein can be combined with one another in a variety of ways. Accordingly, it is to be understood that within the scope of the appended claims, the claimed invention can be practiced in other ways than as specifically described herein.

[0232] All references and publications cited herein are hereby expressly incorporated by reference in their entirety for all purposes, unless to the extent that any aspect is directly inconsistent with this disclosure.

[0233] Unless otherwise specified, all scientific and technical terms used herein have the meanings commonly used in the art. The definitions provided herein are to assist in understanding certain terms that are frequently used herein and are not meant to limit the scope of this disclosure.

[0234] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in this specification and the claims are to be understood as being modified by the term "exactly" or "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein or, for example, within the typical experimental error range.

[0235] Recitation of a numerical range by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. As used herein, the term "up to" or "not greater than" a number (e.g., up to 50) includes that number (e.g., 50), and the term "not less than" a number (e.g., not less than 5) includes that number (e.g., 5).

[0236] Orientation-related terms, such as "upstream" and "downstream", are used to describe the relative positions of components and do not imply a limitation on the absolute orientation of the contemplated embodiments.

[0237] The term "coupled" or "connected" means that elements are attached to each other either directly (in direct contact with each other) or indirectly (with one or more elements between and attaching the two elements). Either term may be modified by "operatively" and "operably", which two terms may be used interchangeably to describe a coupling or connection configured to allow components to interact to achieve a function.

[0238] As used herein, the term "configured to" may be used interchangeably with the term "adapted to" or "constructed to", unless the context of the present disclosure clearly dictates otherwise.

[0239] The term "or" is generally used in its inclusive sense, e.g., to mean "and / or", unless the context clearly dictates otherwise. The term "and / or" means one or all of the listed elements or a combination of at least two of the listed elements.

[0240] The phrases "at least one of...", "including at least one of the following", and "one or more of..." followed by a list refer to any item in the list and any combination of two or more items in the list.

Claims

1. A system, comprising: a hydro separation element including a plurality of hydro separators in series fluid communication, the plurality of hydro separators including at least a first hydro separator and a second hydro separator, each hydro separator defining a curved microfluidic separation channel to separate particles in different size ranges, each microfluidic separation channel defining: an inlet configured to receive a first fluid containing particles, and an outlet including a first flow branch and a second flow branch, wherein, at a specific flow rate, each microfluidic separation channel is configured to direct any particles exceeding a corresponding threshold size into the second flow branch and direct any remaining particles into the first flow branch and the second flow branch, wherein the first flow branch of the first hydro separator is in fluid communication with the inlet of the second hydro separator; and a microfluidic sensing element in fluid communication with the hydro separation element, the microfluidic sensing element including a plurality of microfluidic sensing channels, each microfluidic sensing channel in fluid communication with a different flow branch of the hydro separation element, wherein the plurality of microfluidic sensing channels includes at least: a first microfluidic sensing channel in fluid communication with the second flow branch of the first hydro separator to receive any particles exceeding a first threshold size, and a second microfluidic sensing channel in fluid communication with the second flow branch of the second hydro separator to receive any particles exceeding a second threshold size, wherein the first threshold size is greater than the second threshold size.

2. The system according to claim 1, wherein, the plurality of microfluidic sensing channels includes a third hydro separator in fluid communication with the first flow branch of the second hydro separator.

3. The system according to claim 1 or 2, further comprising: a particle sensor positioned along the plurality of microfluidic sensing channels, the particle sensor configured to provide signal data representative of a signal corresponding to particles in the first fluid; and a controller operably coupled to the particle sensor to receive the signal data, the controller configured to determine the number of particles associated with each size range based on the signal data based on the volume fraction associated with each flow branch.

4. The system according to claim 3, wherein, at least one microfluidic separation channel includes an outlet including a first outlet branch and a second outlet branch, further including at least one flow path selection element positioned at the outlet of at least one microfluidic sensing channel, wherein the controller is operably coupled to the at least one flow path selection element and further configured to control the at least one flow path selection element to direct the fluid flow into the second outlet branch in response to detecting particles in the corresponding microfluidic sensing channel.

5. The system according to claim 3 or 4, wherein, the particle sensor includes a capacitance sensor.

6. The system according to claim 3 or 4, wherein, the particle sensor includes: A light source configured to direct a beam of a certain frequency band along a path through at least one microfluidic sensing channel, wherein the frequency band is selected such that the particles and the first fluid have different light absorption rates; An aperture element defining a light aperture positioned in the path of the beam from the light source; and A light detector positioned to receive the beam in a sensing region after the beam has passed through the light aperture and at least one microfluidic sensing channel, the light detector being configured to provide signal data representative of the amount of light of the frequency band remaining after passing through the at least one microfluidic sensing channel.

7. The system according to claim 6, wherein, The aperture element includes a plurality of light apertures, the plurality of light apertures including a light aperture positioned in the path of the beam from the light source, wherein the plurality of light apertures includes a different set of light apertures aligned with each microfluidic sensing channel, wherein each set of light apertures defines a unique spacing pattern along the corresponding microfluidic sensing channel, and wherein the light detector is positioned to receive the beam in the sensing region after the beam has passed through the plurality of light apertures and the plurality of microfluidic sensing channels, and wherein the controller is configured to determine the number of particles associated with each size range based on the unique spacing pattern.

8. The system according to any one of claims 4-7, wherein, The particles include a second fluid different from the first fluid.

9. The system according to claim 8, wherein, The controller is further configured to determine the amount of the second fluid in the form of microdroplets per unit volume of the first fluid based on the signal data.

10. The system according to claim 9, wherein, The amount does not include the second fluid dissolved in the first fluid.

11. The system according to any one of claims 8-10, wherein, The controller is configured to determine the droplet rate or droplet size of one or more microdroplets of the second fluid dispersed in the flow of the first fluid based on the signal data.

12. The system according to claim 11, wherein, The controller is configured to determine the droplet rate or droplet size based on at least one of the following: The pulse amplitude contained in the signal data, The pulse width contained in the signal data, A first threshold signal level for detecting the smallest size droplets in the sensing region, A second threshold signal level for detecting the droplets filling the sensing region, and The threshold signal level crossing rate.

13. The system according to claim 12, wherein, The controller is further configured to determine at least one of the following: Determine the amount of the second fluid in the form of droplets per unit volume of the first fluid based on the droplet rate and droplet size; Determine the droplet size based on the amplitude of the pulse contained in the signal data in response to the signal not crossing the second threshold signal level; Determine the droplet size based on the width of the pulse contained in the signal data in response to the signal crossing the second threshold signal level; and Determine the droplet size based on the droplet rate.

14. A system, comprising: A plurality of microfluidic sensing channels, each microfluidic sensing channel being configured to receive a flow of a first fluid and particles dispersed in the first fluid, wherein the particles have a different composition from the first fluid; A light source configured to direct a beam of a certain frequency band along a path through the plurality of microfluidic sensing channels, wherein the frequency band is selected such that the particles and the first fluid have different light absorption rates; A pore element defining a plurality of light pores, the plurality of light pores including different sets of light pores aligned with each microfluidic sensing channel, wherein each set of light pores defines a unique spacing pattern along the corresponding microfluidic sensing channel; A light detector positioned to receive the beam in a sensing region after the beam passes through the plurality of light pores of the pore element and through the plurality of microfluidic sensing channels, the light detector being configured to provide a signal representative of the amount of light of the frequency band remaining after passing through the plurality of microfluidic sensing channels; and A controller operably coupled to the light detector and configured to: Determine signal data based on the signal from the light detector, Determine whether particles have passed through the sensing region based on the signal data, and Determine the unique spacing pattern associated with the particles passing through the sensing region based on the signal data.

15. The system according to claim 14, wherein, Each microfluidic sensing channel is configured to receive particles within a different size range, and the controller is further configured to determine the number of particles associated with each size range.

16. The system according to claim 14 or 15, further comprising a hydraulic separation element positioned upstream of the plurality of microfluidic sensing channels, the hydraulic separation element including a plurality of hydraulic separators in series fluid communication, the hydraulic separators including at least a first hydraulic separator and a second hydraulic separator, each hydraulic separator defining a curved microfluidic separation channel to separate particles within different size ranges, each microfluidic separation channel defining: An inlet configured to receive the first fluid and particles dispersed in the first fluid, and An outlet including a first flow branch and a second flow branch, wherein, At a specific flow rate, each microfluidic separation channel is configured to direct any particles larger than a corresponding threshold size into the second flow branch and direct any remaining particles into the first flow branch and the second flow branch, wherein the first flow branch of the first hydraulic separator is in fluid communication with the inlet of the second hydraulic separator.

17. The system according to claim 16, wherein, The controller is further configured to determine the number of particles associated with each size range based on the signal data based on the volume fraction associated with each flow branch.

18. The system according to claim 16 or 17, wherein, The controller is operably coupled to a fluid pump in fluid communication with the hydraulic separation element, the controller being configured to control the fluid pump to direct the first fluid through the hydraulic separation element at a specific flow rate.

19. The system according to any one of claims 16 - 18, wherein, At least one microfluidic sensing channel includes an outlet, the outlet including a first outlet branch and a second outlet branch, and further includes at least one flow path selection element positioned along the outlet of the at least one microfluidic sensing channel, wherein a controller is operatively coupled to the at least one flow path selection element and is further configured to control the at least one flow path selection element to direct a fluid flow to the second outlet branch in response to detecting a particle in the corresponding microfluidic sensing channel.

20. The system according to any one of claims 14-19, wherein, the particle includes a second fluid different from the first fluid, and wherein the controller is further configured to determine an amount of the second fluid in the form of microdroplets per unit volume of the first fluid based on signal data.

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