Systems and methods for separating particles in fluids

Abstract

To provide a system for focusing specific particles in a fluid in various fluid systems and separating the specific particles from the fluid or from particles of other sizes.SOLUTION: Separation elements including microfluidic channels may use a hydrodynamic separator or a flow routing element to separate particles in fluids. Particle sensors may be used to count particles in each microfluidic channel. A unique orifice pattern may be used to facilitate use of a shared particle sensor for multiple microfluidic channels. Separation elements may be used in various systems, such as engine fuel systems, bulk fuel systems, hydraulic particle filters, and hydraulic deaeration enhancers.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 942,009, filed November 29, 2019, the entire disclosure of which is incorporated herein by reference. [Background technology]

[0002] The present disclosure relates to particle separation. In particular, the present disclosure relates to particle separation in a fluid.

[0003] Particles dispersed in a fluid can be problematic in certain systems, such as engine fuel systems, bulk fuel systems, hydraulic systems, or other systems for handling or storing fluids. For example, water (or water droplets) particles in fuel can be problematic in the engine fuel systems of internal combustion engines. Water in fuel can damage fuel injectors through corrosion or vaporization during combustion. Damage to the injectors can cause various problems in engine operation, including failure to comply with local emissions standards. Damaged fuel injectors can require repair or maintenance. Reduced operating time can be particularly costly for commercial or industrial vehicles. In general, the presence of gaseous, liquid, or solid particles dispersed in a fluid can cause problems in various fluid systems, such as bulk fuel systems and hydraulic systems. Traditional fluid filters trap particles within a media structure. Over time, the media structure can become clogged, necessitating maintenance or filter replacement. Summary of the Invention [Problem to be solved by the invention]

[0004] The techniques of the present disclosure generally relate to focusing specific particles in a fluid in various fluid systems and separating the specific particles from the fluid or other sized particles. Generally, the fluid system may include a particle separation element, such as a hydrodynamic separation element, to focus particles within a specific size range. The particle separation element may include an inlet and an outlet having at least two flow branches. Particles within a specific size range may be focused into one of the two flow branches. In some embodiments, particles above a threshold size range are focused into one of the two flow branches. The remaining particles may flow through the at least two flow branches. In some embodiments, the particle separation element may be used to supplement or replace a fluid filter. [Means for solving the problem]

[0005] In one aspect, the present disclosure relates to a hydrodynamic separator. A system includes a hydrodynamic separation element having one or more hydrodynamic separators each defining a curved microfluidic channel in fluid communication with the element. Each microfluidic channel defines an inlet configured to accept a fluid and particles dispersed in the fluid, the particles having a different composition from the fluid, and an outlet including a first flow branch and a second flow branch. At a predetermined flow rate, each microfluidic channel is configured to direct any particles above a corresponding threshold size to the second flow branch and any remaining particles to both the first flow branch and the second flow branch. The system also includes a particle sensor positioned along the one or more hydrodynamic separators and configured to provide signal data representative of the fluid and particles in the fluid. The system further includes 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 hydrodynamic separation element. The control device is configured to control the fluid pump to pass the fluid through the hydrodynamic separation element, determine whether a threshold level of particles is present in the at least one microfluidic channel based on the signal data from the particle sensor, and, in response to determining that the threshold level of particles is present in the at least one microfluidic channel, control the flow rate through the hydrodynamic separation element to pass the fluid through the hydrodynamic separation element at a predetermined flow rate and focus any particles above a corresponding threshold size into a second flow branch of the at least one microfluidic channel.

[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 configured to accept a fluid and particles dispersed in the fluid, the particles having a different composition than the fluid, and an outlet including a first flow branch and a second flow branch. The system also includes a flow routing element positioned along at least one flow branch of the at least one outlet. The system further includes a particle sensor positioned along the one or more microfluidic channels and configured to provide signal data representative of the fluid and particles dispersed in the fluid. The system includes a controller operably coupled to the at least one flow routing element and operably coupled to the particle sensor to receive the signal data. The control device controls the flow routing element to direct the fluid flow to a first flow branch of at least one outlet of the at least one microfluidic channel, determines whether a threshold level of particles is present in the at least one microfluidic channel based on the signal data from the particle sensor, and, in response to determining that the threshold level of particles is present in the at least one microfluidic channel, controls the flow routing element to direct the fluid flow to a second flow branch of the at least one microfluidic channel.

[0007] In another aspect, the present disclosure relates to a particle sorter. The system includes a hydrodynamic separation element having multiple hydrodynamic separators in serial fluid communication, each including at least a first hydrodynamic separator and a second hydrodynamic separator, each defining a curved microfluidic separation channel for separating particles of different size ranges. Each microfluidic separation channel defines an inlet configured to receive a fluid containing particles and an outlet including a first flow branch and a second flow branch. At a specific flow rate, each microfluidic separation channel is configured to direct any particles above a corresponding threshold size to the second flow branch and any remaining particles to both the first flow branch and the second flow branch, with the first flow branch of the first hydrodynamic separator in fluid communication with the inlet of the second hydrodynamic separator. The system also includes a microfluidic sensing element in fluid communication with the hydrodynamic separation element. The microfluidic sensing element includes multiple microfluidic sensing channels, each in fluid communication with a different flow branch of the hydrodynamic separation element. The plurality of microfluidic sensing channels includes at least a first microfluidic sensing channel in fluid communication with a second flow branch of the first hydrodynamic separator to accept any particles above a first threshold size, and a second microfluidic sensing channel in fluid communication with the second flow branch of the second hydrodynamic separator to accept 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 configured to receive a flow of fluid and particles dispersed in the fluid. The particles have a different composition than the fluid. The system also includes a light source configured to direct a light beam within a frequency band along a path through the plurality of microfluidic sensing channels. The frequency band is selected so that the absorbance by the particles differs from the absorbance by the fluid. The system further includes an aperture element defining a plurality of optical apertures, with different sets of optical apertures aligned in each microfluidic sensing channel. Each set of optical apertures defines a unique spacing pattern along the corresponding microfluidic sensing channel. The system also includes a photodetector positioned to receive the light beam at a sensing region after passing through the plurality of optical apertures of the aperture element and the plurality of microfluidic sensing channels. The photodetector is configured to provide a signal representative of the amount of light within the frequency band remaining after passing through the plurality of microfluidic sensing channels. The system further includes a controller operably coupled to the photodetector and configured to determine signal data based on the signal from the photodetector, determine based on the signal data whether the particle has passed through the sensing region, and determine based on the signal data a unique spacing pattern associated with the particle passed through the sensing region.

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

[0010] In a further aspect, the present disclosure relates to an engine fuel system. The system includes a fuel line configured to deliver fuel to a fuel injector system. The system also includes a hydrodynamic separation element having one or more hydrodynamic separators, each defining a curved microfluidic channel for separating particles in the fuel. Each microfluidic channel is in fluid communication with the fuel line and defines an inlet for receiving fuel, and an 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.

[0011] In another aspect, the present disclosure relates to a bulk fuel system. The system includes a fuel line configured to deliver fuel from a bulk fuel storage tank to a vehicle fuel tank. The system also includes a hydrodynamic separation element having one or more hydrodynamic separators, each defining a curved microfluidic channel for separating particles in the fuel. Each microfluidic channel defines an inlet in fluid communication with the fuel line for receiving fuel, and an outlet including a first flow branch in fluid communication with the fuel line for supplying fuel to the vehicle fuel tank, and a second flow branch for receiving 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 also includes a hydrodynamic separation element having one or more hydrodynamic separators, each defining a curved microfluidic channel for separating particles in the hydraulic fluid. Each microfluidic channel defines an inlet in fluid communication with the hydraulic fluid line for receiving hydraulic fluid from the hydraulic pump, and an outlet in fluid communication with the hydraulic fluid line, the outlet including a first flow branch for providing hydraulic fluid to the hydraulic component and a second flow branch for receiving particles within a specific size range.

[0013] In yet another aspect, the present disclosure relates to improved hydraulic degassing. A system includes a hydraulic fluid return line configured to deliver hydraulic fluid from a hydraulic component to a hydraulic pump. The system includes a hydrodynamic separation element having one or more hydrodynamic separators, each defining a curved microfluidic channel for separating particles in the hydraulic fluid. Each microfluidic channel defines an inlet in fluid communication with the hydraulic fluid line for receiving hydraulic fluid from the hydraulic pump, and an outlet in fluid communication with the hydraulic fluid line, the outlet including a first flow branch for providing hydraulic fluid to the hydraulic pump and a second flow branch for receiving particles within a specific size range.

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

[0015] [Figure 1] FIG. 1 is a conceptual diagram illustrating an example of a fluid system including a particle separation element configured to receive a fluid flow from a fluid source according to the present disclosure. [Figure 2] 2 is a conceptual diagram illustrating an example of a fluid system that can be used to process fuel in a machine that can be used with the particle separation element of FIG. 1. [Figure 3] FIG. 2 is a conceptual diagram illustrating an example of a fluid system that can be used to process bulk fuel that can be used with the particle separation element of FIG. 1. [Figure 4] FIG. 2 is a conceptual diagram illustrating one example of a fluid system that can be used to deliver hydraulic fluid usable with the particle separation element of FIG. 1. [Figure 5] FIG. 2 is a conceptual diagram illustrating one example of a fluid system that can be used to degas a hydraulic fluid that can be used with the particle separation element of FIG. 1. [Figure 6] FIG. 2 is a conceptual diagram illustrating an example of an optical or light-based particle sensor that may be used in the particle sensor of FIG. 1. [Figure 7] FIG. 2 is a conceptual diagram illustrating an example of a configuration for using the particle sensor of FIG. 1 with a microfluidic channel. [Figure 8] FIG. 2 is a conceptual diagram illustrating another example of a configuration for using the particle sensor of FIG. 1 with a microfluidic channel. [Figure 9] FIG. 2 is a conceptual diagram illustrating another configuration for using the particle sensor of FIG. 1 in conjunction with a particle separation element and a microfluidic sensing element. [Figure 10] FIG. 2 is a conceptual diagram illustrating another configuration for using the particle sensor of FIG. 1 in conjunction with a particle separation element and a microfluidic sensing element. [Figure 11A] FIG. 2 is a conceptual diagram illustrating an example of a technique for counting the number of particles in multiple microfluidic channels using a shared photodetector that can be used with the particle sensor of FIG. 1. [Figure 11B] FIG. 2 is a conceptual diagram illustrating an example of a technique for counting the number of particles in multiple microfluidic channels using a shared photodetector that can be used with the particle sensor of FIG. 1. [Figure 12] FIG. 2 is a conceptual diagram illustrating an example of a fluid system that can be used to remove particles, which can be used with the particle separation element of FIG. 1. [Figure 13A] 1A-1C are images and plots showing a hydrodynamic separator device and pixel intensity versus channel position, respectively. [Figure 13B] 1A-1C are images and plots showing a hydrodynamic separator device and pixel intensity versus channel position, respectively. [Figure 13C] 1A-1C are images and plots showing a hydrodynamic separator device and pixel intensity versus channel position, respectively. [Figure 13D] 1A-1C are images and plots showing a hydrodynamic separator device and pixel intensity versus channel position, respectively. [Figure 14] FIG. 13B is a conceptual diagram showing the relative positions of angles around the hydrodynamic separator device of FIGS. 13A-D. [Figure 15] 13A-13D are plots showing focusing ratio versus channel length for the hydrodynamic separator device of FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the following detailed description, reference is made to certain specific embodiments. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present disclosure. Therefore, the following detailed description is not to be taken in a limiting sense.

[0017] The present disclosure provides techniques for focusing specific particles in a fluid and separating the specific particles from the fluid or other sized particles in various fluid systems. Generally, a fluid system may include a particle separation element, such as a hydrodynamic separation element, to focus particles within a specific size range. The particle separation element may include an inlet and an outlet having at least two flow branches. Particles within a specific size range may be focused into one of the two flow branches. In some embodiments, particles above a threshold size range are focused into one of the two flow branches. The remaining particles may flow through the at least two flow branches. In some embodiments, the particle separation element may be used to supplement or replace a fluid filter.

[0018] Particle separation elements, which may include hydrodynamic separation elements, can be used as an alternative or complement to filters. In particular, particle separation elements can be used to concentrate particles above a critical size in a portion of the fluid flow. This portion of the fluid flow can be removed from the system, thereby removing most particles above a threshold size. In some cases, this can replace some or all of the function of a filter. The performance of the particle separation element may not change over time and may not require periodic replacement. In some embodiments, a filter can be used downstream of the particle separation element to remove particles below a threshold size. Furthermore, in some embodiments, particles concentrated by the particle separation element are filtered. This can be done at a lower face velocity than in systems without a particle separation element, resulting in lower pressure drop across the filter and longer filter life.

[0019] Particle separation elements, which may include hydrodynamic separation elements, can also be used to separate particles of different sizes. In some applications, a threshold size may be determined. The particle separation element can be designed to concentrate particles above the threshold size into a concentrated fluid portion of the fluid stream. The concentrated portion of the fluid stream 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 concentrate specific materials for collection.

[0020] A microfluidic particle sensor or microfluidic sensing element can be used to detect individual contaminants in a fluid, such as a liquid stream. A separator or segmentation stage can be positioned upstream of the particle sensor. The segmentation stage or particle separation element can separate particles into different fluid streamlines based on particle size. This can be achieved, for example, using Dean flow separation. Particles enter several streamlines based on particle size, and each streamline is sent to a different sensing channel of the microfluidic sensing element. The sensing channels are associated with particle sensors that count the number of particles. By knowing the number of particles in each sensing channel, an approximate particle size distribution can be determined. The sensors can be optical, capacitive, magnetic, or other sensors. Alternatively, the particle sensor can include only a microfluidic channel and a sensor. The use of a microfluidic channel can increase sensitivity to individual contaminants compared to other techniques, such as Mie scattering. Signal processing can also be used to identify the type of contaminant.

[0021] Additionally, particle separation elements, which may include hydrodynamic separation elements, can be used for selective particle waste removal. In some cases, only particles above a certain size may be targeted for removal from the system. Uses for selective particle waste removal may include, but are not limited to, fat removal or concentration in milk (fat is typically in agglomerates between 0.1 and 15 micrometers), orange juice pulp removal or concentration, contaminant removal in semiconductor processing fluids, and ink agglomerate removal in industrial ink processing. In one example involving wafer polishing slurries, particle separation elements can be designed to remove particles above a threshold size, which may be agglomerates or impurities, and allow particles below the threshold size to pass.

[0022] definition particle As used herein, the term "particle" refers to a discrete amount of material that may be dispersed in various fluids. Non-limiting examples of materials that may form particles include dirt, metal, air bubbles, and water droplets. In one particular example, water droplets may be dispersed in a hydrocarbon fluid, such as gasoline or diesel fuel, to create an emulsion. In another example, air bubbles may be dispersed in a hydraulic fluid.

[0023] Upstream / downstream As used herein, the term "downstream" refers to the direction along with the fluid flow. The term "upstream" refers to the opposite of downstream, or the direction against the fluid flow.

[0024] Microfluidic Channels As used herein, the term "microfluidic channel" refers to a channel having at least one dimension less than 1 millimeter (1000 micrometers). A microfluidic channel may have a channel width less than 1000 micrometers, a channel height (or depth) less than 1000 micrometers, or both. In some embodiments, for higher flow rate applications, at least one dimension of a microfluidic channel can be greater than 1 millimeter. In some embodiments, at least one dimension of a microfluidic channel is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 millimeters or more, or 10, 9, 8, 7, 6, 5, 4, 3, or 2 millimeters or less. In general, a channel can have any suitable length to provide an appropriate pressure drop balanced with appropriate particle focusing.

[0025] A microfluidic channel can be described by its cross-sectional area, i.e., width x height. In some embodiments, the cross-sectional area of ​​a microfluidic channel can be less than 10, 9, 8, 7, 6, 5, 4, 3, or 2 millimeters square.

[0026] A microfluidic channel can also be described by its hydraulic diameter. For example, for a microfluidic channel with a rectangular cross section, the hydraulic diameter can be calculated as follows:

number

[0027] Hydrodynamic Separator As used herein, the term "hydrodynamic separator" refers to a curved fluid channel including at least an inlet for receiving a fluid flow and an outlet including at least two branches for splitting the fluid flow. The fluid channel may be a microfluidic channel. The inlet may receive a fluid that may contain particles of various sizes. At a certain flow rate, the hydrodynamic separator is configured to focus particles above a threshold size into one branch. The remaining particles are not focused into the fluid flow. The remaining particles can be divided among all branches based on, for example, the volume fraction or outlet flow rate ratio associated with each branch. The hydrodynamic 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 rate ratio, or any combination thereof. The hydrodynamic separator may also be referred to as a Dean flow separator.

[0028] Generally, a hydrodynamic separator includes a curved microfluidic channel designed to focus particles above a threshold size onto the inner wall of the curve. The cross-sectional area of ​​the microfluidic channel limits the maximum particle size that can enter the microfluidic channel. The device defines a geometry (width, height, radius of curvature, channel length, etc.) designed to focus particles in a known fluid at a specific flow rate or flow rate range. The focused particles near the inner wall can then be removed from the system by removing a portion of the fluid near the inner wall. In other embodiments, depending on the device geometry and operating conditions, particles and waste streams may alternatively be focused near the outer wall. The device design may depend on the flow rate, fluid properties (such as viscosity and density), and threshold particle size of the application. The hydrodynamic separator may function as a filter or prefilter within the system.

[0029] Curved microfluidic channels can be used to focus particles of a given size under appropriate flow conditions. In a curved channel or pipe under laminar flow conditions, fluid inertia creates a pressure gradient across the channel. To alleviate the pressure gradient, two spiral flows known as Dean flows (sometimes called secondary flows) can occur. Dean flows can exert a drag force on any particle in the fluid. In larger channels, particles can be swept along the channel in a spiral motion. When channels become smaller, such as microfluidic channels, Dean flows can be balanced by two additional forces, which can trap and focus particles on the inner wall of the curved channel. These forces can be represented as a shear-induced lift force, which causes lift toward the wall, and a wall-induced lift force, which pushes particles away from the wall due to the rebound of the fluid flow as they approach the wall. Particles can be focused into specific streamlines within a curved channel. Focusing particles in this way is sometimes called hydrodynamic or Dean flow separation.

[0030] Flow Routing Elements As used herein, a "flow routing element" refers to a component configured to enable selective routing of a fluid flow exiting a fluid channel. Non-limiting examples of flow routing element components include valves or solenoids. In one example, a flow routing element may include one or more valves configured to divert the flow into one or more branches in any suitable manner.

[0031] Dean number The Dean number describes the behavior of a fluid in a curved pipe and takes into account the inertial, centripetal, and viscous forces acting on the fluid. In various embodiments, the system is configured to have a Dean number between 5 and 25. The Dean number is defined as:

number

[0032] Reynolds number The Reynolds number represents the ratio of inertial forces to viscous forces and is defined as follows:

number

[0033] Reference will now be made to the drawings, which illustrate one or more aspects described in the present disclosure. However, it should be understood that other aspects not shown in the drawings are also within the scope of the present disclosure. Like numbers used in the figures represent like components, steps, etc. However, it should be understood that the use of a reference number to refer to an element in a given figure is not intended to limit the element in another figure bearing the same reference number. Furthermore, the use of different reference numbers to refer to elements in different figures is not intended to indicate that the differently referenced elements may not be identical or similar.

[0034] FIG. 1 is a conceptual diagram illustrating an example of a fluid system 100 including a particle separation element 102 configured to receive a fluid flow from a fluid source 104. The fluid system 100 may be any suitable type of system that can benefit from the use of the particle separation element 102, such as an engine fuel system, a bulk fuel system, or a hydraulic system. The fluid source 104 may be configured to contain a fluid that may contain particles. The particle separation element 102 may be used as a filter to facilitate the removal of particles within a certain size range from the fluid. For example, particles that are considered contaminants or waste may be removed. Additionally or alternatively, the particle separation element 102 may be used to facilitate the separation of particles of different sizes. By separating particles of different sizes, the fluid system 100 may determine the number of particles that fall within different size ranges.

[0035] The particle separation element 102 can be fluidly coupled between a 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 a fluid, such as fuel consumed by an engine. The fluid destination 108 can be a component of the fluid system 100 that uses a fluid, such as hydraulic fluid used in a hydraulic piston, and returns the fluid to the fluid source 104. 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.

[0036] The particle separation element 102 can include any suitable component usable to remove or sort particles in a fluid. In some embodiments, the particle separation element 102 includes a hydrodynamic separation element. Generally, the particle separation element 102, which may include a hydrodynamic separation element, may not be subject to particle loading and may not change in performance over time or require periodic replacement.

[0037] The hydrodynamic separation element may include one or more hydrodynamic separators. In some embodiments, the hydrodynamic separators are arranged in parallel. The channel length and arrangement of the hydrodynamic separators can be designed to provide a target pressure drop.

[0038] In some embodiments, the particle separation element 102 includes a flow routing element. The flow routing element can be disposed at an outlet of the particle separation element 102. The flow routing element can include one or more valves or solenoids for diverting the fluid flow.

[0039] Generally, the particle separation element 102 includes an outlet with at least two different branches. The fluid stream may be split between the different branches. In some embodiments, a hydrodynamic separation element may be used to focus all particles within a particular size range into one of the branches. Each branch may be associated with particles within a different size range (see Figures 9-10).

[0040] Each branch may be directed to or in fluid communication with a different fluid destination. In some embodiments, one branch may be directed to fluid destination 106 and another branch may be directed to fluid destination 108.

[0041] A fluid pump 114 can be used to control the flow rate of fluid through the particle separation element 102. The fluid pump 114 can be positioned at any suitable location relative to the particle separation element 102 to facilitate flow rate control, such as upstream of the particle separation element, downstream of the particle separation element, or integral with the particle separation element. In the illustrated embodiment, the fluid pump 114 is positioned upstream of the particle separation element 102.

[0042] The particle sensor 112 can be used to detect any particle in the fluid stream. The particle sensor 112 can be positioned in any suitable location relative to the particle separation element 102 to facilitate detection of a particular particle, such as upstream of the particle separation element, downstream of the particle separation element, or integrated with the particle separation element. In some embodiments, the particle sensor 112 can be positioned between the inlet and 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 ( FIG. 6 ) or a capacitance-based sensor.

[0043] The microfluidic sensing element 116 can be used to sense particles of different sizes from one or more 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 may be represented as part of the particle separation element 102. The microfluidic sensing element 116 may 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 focusing.

[0044] 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 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 properly removed some or all particles within a particular size range. The microfluidic sensing element 116 can also include a flow routing element. The flow routing element can be used to facilitate the removal of particles within a particular size range.

[0045] A fluidic subsystem 120 may be defined, which may include one or more of the particle separation element 102, the fluid pump 114, the microfluidic sensing element 116, and the controller 110. The controller 110 may be used to facilitate various functions of the fluidic subsystem 120 described herein.

[0046] Various configurations of the fluid system 100 are contemplated. Non-limiting examples of additional configurations and various components of the fluid system 100 are illustrated and described in more detail herein.

[0047] In one example, sometimes referred to as a kidney loop filter (not shown), a fluid pump 114 can be used to provide a fluid flow from a fluid source 104 or source reservoir through a particle separation element 102, which may include a hydrodynamic separator element, which returns the main flow through a filter to the fluid source 104. Industrial systems using liquid fluids can use kidney loop filtration systems 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 a secondary outlet flow containing certain particles back to the filter, which can concentrate the particles, minimize the volume of fluid that needs to be filtered, reduce face velocity, and reduce the pressure drop across the filter.

[0048] One or more of the components of a controller, sensor, detector, or system described herein may include a processor, e.g., a central processing unit (CPU), computer, logic array, or other device that allows data to flow into and out of the component. A processor may include one or more computing devices having memory, processing, and communication hardware. A processor may include circuitry used to couple various components of the controller together or with other components operatively coupled to the controller. The functions of the processor may be implemented by hardware and / or as computer instructions residing on a non-transitory computer-readable storage medium.

[0049] A processor may include any one or more of a microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA), and / or equivalent discrete or integrated logic circuitry. In some examples, a processor may include multiple components, such as one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, and / or one or more FPGAs, and any combination of other discrete or integrated logic circuitry. Functionality attributed to a processor herein may be embodied as software, firmware, hardware, or any combination thereof.

[0050] In one or more embodiments, the processor functionality may be implemented using one or more computer programs using a computing device, 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 desired output data / information. The output data / information may be applied as input to one or more other devices and / or methods, as described herein or applied in a known manner. In view of the above, it should be readily apparent that the controller functionality described herein may be implemented in any manner known to those skilled in the art.

[0051] 2 is a conceptual diagram illustrating one example of a fluid system that can be used to process fuel in a machine using a particle separation element 102. The particle separation element 102, which may include a hydrodynamic separator element, can be used in a fluid system 120, such as an engine fuel system, and can replace the use of a primary filter along a main fuel line 122. In an engine fuel system, a lift pump draws fluid from a fuel tank and pushes the fluid into a high-pressure common rail. Some fuel can be returned to the fuel tank from the fuel injector system in a fuel return line 128.

[0052] As shown, a fluid pump 114, such as a fuel pump or lift pump, may be used to provide a fluid flow, such as fuel, from a fluid source 104, such as a fuel tank, through a main fuel line 122 through the particle separation element 102. The particle separation element 102 may provide a main outlet flow along the main fuel line 122 to a fluid destination 106, such as a fuel injector system, which may include a high-pressure common rail, using a first flow branch 123, and a secondary outlet flow, containing certain particles, back to the fluid source 104 along a second flow branch 124. Non-limiting examples of particles include dirt and water droplets.

[0053] The particle separation element 102 may 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 may be positioned downstream of the particle separation element 102 along the main fuel line 122. The filter 126, or fuel filter, may be configured to filter particles from gasoline or diesel fuel. The fluid system 120 may 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 may be positioned along the second flow branch 124, or another filter 126 may be positioned along the second flow branch 124, which may filter particles at a lower flow rate and pressure drop.

[0054] The particle separation element 102 can be configured to remove particles above or larger than a particular threshold size in diameter from the main fuel line 122, and the fluid pump 114, which provides fuel at a particular flow rate for engine operation, provides such particles to the second flow branch 124. Non-limiting examples of the particular threshold size include 1, 2, 5, 10, 15, or 20 micrometers.

[0055] 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 primarily free of particles above a threshold size. The clean outlet stream may be routed to a filter 126 and ultimately to a fluid destination 106, shown as a high-pressure common rail of a fuel injector system. The dirty outlet stream may contain most of the particles above a critical size. The dirty stream may be routed back to the fluid source 104, shown as a fuel tank. In other embodiments, the dirty outlet stream may be combined with a fuel return line extending from the high-pressure common rail system. In other words, the second flow branch 124 may be fluidly coupled to a fuel return line 128 before returning to the fluid source 104. The particle separation element 102 may have a mechanism, such as a valve (not shown), for controlling the dirty outlet flow along the second flow branch 124, to facilitate operation as the filter pressure limit increases over time due to loading of the filter 126 along the first flow branch 123.

[0056] 3 is a conceptual diagram illustrating 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 may include a hydrodynamic separator element, can be used in a fluid system 140, such as a fuel dispensing station, to remove particles before providing the fuel to a fluid destination 106, such as a vehicle.

[0057] As shown, a fluid pump 114 may be used to provide a fluid flow, such as fuel, from a fluid source 104, such as a bulk fuel storage tank, to a main fuel line 142 through a particle separation element 102. The particle separation element 102 may provide a main outlet flow along the main fuel line 142 to a fluid destination 106, such as a vehicle, using a first flow branch 143, and a secondary outlet flow containing certain particles along a second flow branch 144 for return to the fluid source 104 or for delivery to a fluid destination 108, such as a secondary storage tank. Non-limiting examples of particles include dirt and water droplets.

[0058] The particle separation element 102 may 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 146 may be positioned downstream of the particle separation element 102 along the main fuel line 122. The filter 146, or fuel filter, may be configured to filter particles from gasoline or diesel fuel. The fluid system 120 may 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 may be positioned along the second flow branch 144, or another filter 146 may be positioned along the second flow branch 144, which may filter particles at a lower flow rate and pressure drop.

[0059] The particle separation element 102 can be configured to remove particles larger than a certain diameter threshold size from the main fuel line 122, and the fluid pump 114 provides fuel at a certain flow rate suitable for the fuel dispensing station and provides such particles to the second flow branch 144.

[0060] 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 143 to the main fuel line 142, and a “dirty” outlet stream along a second flow branch 144. The clean outlet stream may be primarily free of particles above a threshold size. The clean outlet stream may be routed to a filter 126 and ultimately to a fluid destination 106, shown as a high-pressure common rail. The dirty outlet stream may contain most of the particles above a critical size. The dirty outlet stream may be routed back to the fluid source 104, shown as a bulk fuel storage tank, or to a fluid destination 108, shown as a separate tank for containing dirty or contaminated fuel. The particle separation element 102 may have a mechanism, such as a valve (not shown), for controlling the dirty outlet stream along the second flow branch 144, allowing for easier operation as the filter pressure limit increases over time due to loading of the filter 146 along the first flow branch 143.

[0061] 4 is a conceptual diagram illustrating one example of a fluid system that can be used to deliver hydraulic fluid using a particle separation element 102. The particle separation element 102, which may include a hydrodynamic separator element, can be used in a fluid system 160, such as a hydraulic cylinder system, to remove particles before delivering hydraulic fluid to hydraulic components, such as actuation cylinders, to protect the hydraulic components from particles.

[0062] As shown, a fluid pump 114, such as a fuel pump, may be used to provide a fluid flow from a fluid source 104, such as a hydraulic fluid reservoir, through the particle separation element 102, and into a main fuel line 162. The fluid source 104 may be in fluid communication with an inlet of the fluid pump 114. The particle separation element 102 may provide a main outlet flow along the main fuel line 162 to a fluid destination 106, such as a hydraulic component that may include an actuator cylinder, using a first flow branch 163, and a secondary outlet flow containing certain particles along a second flow branch 164 back to the fluid source 104. Non-limiting examples of particles include dirt, air bubbles, and water droplets. The fluid system 160 may also include a fluid return line 168 from the fluid destination 106 to the fluid source 104. The second flow branch 164 may be fluidly coupled to the fluid return line 168 before returning to the fluid source 104.

[0063] 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. The 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 are combined before reaching the filter 166. The filter 166 can be in fluid communication with the fluid source 104.

[0064] 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 163 to the main fuel line 162, and a “dirty” outlet stream along a second flow branch 164. The clean outlet stream can proceed to a fluid destination 106, shown as a hydraulic component. The dirty outlet stream can merge into a fluid return line 168, which will pass through a filter 166 before returning to the fluid source 104, shown as a fluid reservoir. The particle separation element 102 can be designed to operate over a variety of temperatures, flows, and system configurations (e.g., hydraulic cylinder extensions).

[0065] 5 is a conceptual diagram illustrating one 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 may include a hydrodynamic separator element, can be used in a fluid system 180, such as a hydraulic cylinder system, to remove nucleated gas bubbles before returning the hydraulic fluid to a fluid source 104, such as a main hydraulic fluid reservoir, to protect fluid destinations 106, such as hydraulic components, from gas bubbles.

[0066] As shown, a fluid pump 114, such as a hydraulic fluid pump, may 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 may include an actuator cylinder. A return fluid flow may be provided from the fluid destination 106 along a fluid return line 188 to a nucleation filter 169 to nucleate bubbles in the fluid. The particle separation element 102 may be positioned downstream of the nucleation filter 169. The nucleation filter 169 may be in fluid communication with an inlet of the particle separation element 102 and the fluid destination 106. The particle separation element 102 may provide a main outlet flow to the fluid source 104 using a first flow branch 183 along the fluid return line 188 and a secondary outlet flow containing specific particles along a second flow branch 184 to the fluid destination 108, such as a settling reservoir or an aerated oil collection volume. The fluid destination 108 may be in restricted flow fluid communication with the fluid source 104 to allow the aerated hydraulic fluid to collect and settle.

[0067] The fluid in the hydraulic fluid system 180 is pressurized by the fluid pump 114. The pressurized fluid can dissolve more air. When the fluid is depressurized in the fluid return line 188, the fluid can become supersaturated with air, which can lead to the nucleation and formation of air bubbles in the fluid stream. The air bubbles can be removed before the fluid is pumped again by the fluid pump 114. Air bubbles that reach the fluid pump 114 can cause cavitation, which can create noise and damage the fluid pump. A nucleation filter 169 can be used to nucleate and grow the air bubbles. The bubble-laden fluid can be sent through the particle separation element 102, which may include a hydrodynamic separator. The air bubbles can be concentrated in the “aerated oil return” outlet flow along the second flow branch 184. The aerated oil return outlet flow can be returned to the fluid destination 108 or a settling reservoir in a volume that allows natural bubble settling. Fluid destination 108 may be a separate compartment within the same vessel as fluid destination 106. A "main return" along with the outlet flow, free of bubbles, may be sent along fluid return line 188 to fluid destination 106 and immediately available for use by fluid system 180.

[0068] FIG. 6 is a conceptual diagram illustrating an example of an optical or light-based particle sensor 200 that can be used in or as particle sensor 112 (FIG. 1). Generally, any suitable type of particle sensor can be used, including, for example, those described in PCT Application No. PCT / US2019 / 034809, filed May 31, 2019, which is incorporated by reference. When particle sensor 200 is used to detect droplets of fluid, particle sensor 200 may also be referred to as a droplet sensor. Particle sensor 200 can be operably coupled to controller 110 and optically coupled to microfluidic channel 201, which can be part of a hydrodynamic separator of particle separation element 102 (FIG. 1) or part of microfluidic sensing element 116 (FIG. 1).

[0069] As shown, particle sensor 200 includes a light source 202, a light aperture 204, and a light detector 206. Controller 110 may be operably connected to light detector 206 and may also be operably connected to light source 202.

[0070] 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, such as droplets, bubbles, dirt, metal, etc., in the flow of fluid 208 that can flow through the microfluidic channel 201.

[0071] Particles 210 may be dispersed in fluid 208 within microfluidic channel 201. For example, particles 210 may be suspended in fluid 208 in a separate phase or may be of a different composition or substance. In other words, particles 210, which may be a liquid, are not dissolved in fluid 208. In one example, particles 210 may comprise a different fluid than fluid 208.

[0072] Generally, the microfluidic channel 201 is sized to accept one or more particles 210 at a time. In some embodiments, the microfluidic channel 201 has a cross-sectional area sized to accept one particle 210 of a predetermined size at a time. In particular, the cross-sectional area of ​​the microfluidic channel 201 can be approximately the same size as the cross-sectional area of ​​the particle 210, which can facilitate counting one particle 210 at a time and facilitate accurate counting and sizing of the particles 210.

[0073] The cross-sectional area can be defined perpendicular to the direction of flow of the fluid 208. In other words, the cross-sectional area can be expressed as across the longitudinal flow of the fluid 208. The cross-sectional area can be defined as the product of the channel height (or depth) multiplied by the channel width. Both the channel height and the channel width can be perpendicular to the direction of flow of the fluid 208. In some embodiments, the channel depth is less than or equal to the channel width. Using a relatively shallow channel depth can prevent particles 210 from stacking or getting hidden behind each other between the light source 202 and the photodetector 206 as they flow through the microfluidic channel 201, thereby increasing the chances of each particle being detected.

[0074] light source 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.

[0075] 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 to pass through the microfluidic channel 201. The light beam 214 may be collimated or substantially collimated by the light aperture 204 over at least a path length of the light beam 214 through the microfluidic channel 201. The light beam 214 may define a beam axis that extends through the microfluidic channel 201. The walls of the microfluidic channel 201 may be formed of an optically transparent material at least to the light 212 provided by the light source 202.

[0076] The path of the light beam 214 that intersects the microfluidic channel 201 defines a sensing region 216, which may also be referred to as a sensing volume, in which the particle 210 may be detected. After the light beam 214 passes through the microfluidic channel 201, it is received by a photodetector 206, which may be positioned outside the microfluidic channel 201. When the particle 210 and fluid 208 are in the sensing region 216, the photodetector 206 may be used to determine the absorbance of the light beam 214 by the particle 210 and fluid 208 to detect, size, or otherwise characterize the particle 210.

[0077] As used herein, the term "path length" refers to the distance that light from the light source 202 travels through the fluid being measured. In some embodiments, the path length may be approximately equal to the width or depth of the microfluidic channel 201. The path length may also be reduced to improve sensitivity to particles 210. In some embodiments, the path length is 2000, 1000, 500, 300, 250, 200, 150, or 100 micrometers or less. In one or more embodiments, the path length is 1000 micrometers or less.

[0078] Light source 202 is configured to generate light within a selected frequency band such that particles 210 have a different absorbance than fluid 208 within the selected frequency band. In one or more embodiments, for example, when the liquid is water and fluid 208 is a hydrocarbon fluid, particles 210 have a higher absorbance than fluid 208. In a fuel system application, for example, light source 202 may generate light 212 at least within a near-infrared (NIR) frequency band. In some embodiments, NIR light 212 may include an emission peak in the range of 1400 to 1600 nanometers, or at least include frequencies within that range. In particular, NIR light 212 may include an emission peak centered at or near 1550 nanometers. In some embodiments, NIR light 212 may include an emission peak in the range of 900 to 1100 nanometers, or at least include frequencies within that range. In particular, NIR light 212 may include an emission peak centered at or near 1000 nanometers.

[0079] The light source 202 may include any suitable type of light source capable of providing light 212 within a selected frequency band. In some embodiments, the light source 202 is a light emitting diode (LED). The LED light source 202 may be a low-power LED. In some embodiments, the LED light source emits light omnidirectionally or omnidirectionally from a light emitting junction. In some embodiments, the LED light source emits light primarily in one direction. In some embodiments, the light source 202 may be paired with or include a fiber optic cable that directs light into the microfluidic channel 201. An optical aperture 204 may be used to allow a narrow light beam 214 to pass through the microfluidic channel 201, which may facilitate the removal of noise or erroneous signals due to, for example, scattering and reflections.

[0080] The optical aperture 204 may be or may include at least one opening in the aperture element 218. As used herein, "aperture" refers to an opening or void in the aperture element 218. The optical aperture 204 may have a width sized relative to the microfluidic channel 201 and the optical detector 206 to facilitate optimal sensitivity for detecting particles 210 in the fluid 208. In some embodiments, the width of the optical aperture 204 is the same as or substantially the same as the channel width of the microfluidic channel 201.

[0081] Additionally or alternatively, the optical aperture 204 may be sized for a predetermined particle size of interest. For example, in some embodiments, the width of the optical aperture 204 may be designed to be 2, 3, 4, 5, 6, 7, 8, 9, or 10 times or less the particle size of interest. In some embodiments, the width of the optical aperture 204 may be designed to be 1, 2, 3, 4, 5, 6, 7, 8, or 9 times or more the particle size of interest.

[0082] The light aperture 204 can have any suitable geometric shape. In some embodiments, the light aperture 204 has a round or circular shape, such as a circle or an ellipse. In some embodiments, the light aperture 204 has a polygonal shape, such as a triangle, square, trapezoid, or rectangle. The light aperture 204 can have a length that can extend along the same direction as the flow of the fluid 208. In one or more embodiments, the length of the light aperture 204 can be the same as or substantially the same as the width of the light aperture 204.

[0083] Photodetector The photodetector 206 may be any suitable type of photodetector sensitive to a selected frequency band, which may be the NIR frequency band. The photodetector 206 is also configured to provide a signal representative of the amount of light from the light beam 214 remaining after passing through the microfluidic channel 201. In particular, the photodetector 206 may be configured to generate an electrical signal, such as a current, voltage, or power signal, in response to receiving light within the selected frequency band. Non-limiting examples of types of photodetectors include indium-gallium-arsenide (InGaAs), germanium (Ge), or silicon (Si) photodiodes. For example, an InGaAs photodiode may be sensitive to light 212 within the frequency band of 1100 to 1700 nanometers. A Ge photodiode may have a peak sensitivity at 1550 nanometers. A Si photodiode may be used for visible light.

[0084] Control device The controller 110 can be configured to detect, size, or otherwise characterize one or more particles 210 dispersed in the flow of fluid 208 based on the signal from the photodetector 206. In some embodiments, the controller 110 can be configured to detect one particle 210 dispersed in the flow of fluid 208 at a time, particularly a particle of a predetermined size.

[0085] Generally, when the particles 210 are fluid, they may also be referred to as droplets. When the particles 210 are liquid, the signal can be used to determine the amount of liquid (e.g., water) per unit volume of the fluid 208 (e.g., a hydrocarbon fluid), excluding any liquid dissolved in the fluid.

[0086] In some embodiments, the controller 110 is configured to determine particle velocity through the sensing region 216. For example, a change in absorbance detected based on the signal from the photodetector 206 may indicate that the particle 210 is entering or exiting the sensing region 216. Alternatively or additionally, the controller 110 may be configured to determine particle size. In some embodiments, the controller 110 may determine particle velocity or particle size based on at least one of the following: the magnitude of a pulse contained in the signal; the width of a pulse contained in the signal; a first threshold signal level for detecting a particle of a minimum size within the sensing region; a second threshold signal level for detecting particles that fill the sensing region; and a threshold signal level crossing rate. When the particles are fluid, the controller 110 may determine the amount of particles 210 in droplet form per unit volume of the fluid 208, such as particle concentration, based on the particle velocity, the particle size, or both. In some applications, such as non-engine applications, when the particle velocity is constant or substantially constant, the particle velocity may be used to estimate or determine particle size or concentration.

[0087] In some embodiments, the controller 110 is further configured to determine the amount of particles 210 in droplet form per unit volume of the fluid 208 based on the droplet velocity and the droplet size. The controller 110 can also be configured to determine the particle size based on the magnitude of a pulse included in the signal data in response to the signal not exceeding a second threshold signal level. Additionally, the controller 110 can also be configured to determine the particle size based on the width of a pulse included in the signal data in response to the signal exceeding the second threshold signal level. Additionally, the controller 110 can also be configured to determine the particle size based on the particle velocity.

[0088] Capacitance-Based Sensors In other embodiments, a capacitance-based sensor (not shown) can be used as the particle sensor 112. To detect single particles and assess the cleanliness of the fuel, a capacitance sensor can be fabricated in the microfluidic channel 201, for example, near the outlet. The capacitance sensor can be used to detect particles 210, such as water or other liquid droplets or metal particles. The capacitance sensor may include interdigitated electrodes to form a planar capacitor. The capacitance of the channel can be calculated from the following equation:

number

number

[0089] Capacitive sensors can be used to sense various particles in fluids, for example, when the difference in dielectric constant between the particle material and the fluid is sufficient to generate a significant signal. Table 1 below shows the dielectric constants for various particles and fluids. Particle materials with a larger difference in dielectric constant from the background fluid can generate a larger signal difference. In general, the signal can be related to the particle size in addition to the difference in dielectric constant between the particle and the background fluid. If the size is known (or approximately known) (which can be determined by using particle separation element 302 (see Figures 9-10)), the signal can be used to determine the difference in dielectric constant and, optionally, the contaminant.

[0090] [Table 1]

[0091] 7 is a conceptual diagram illustrating one example of a configuration 220 for using the particle sensor 112 with a microfluidic channel 221. The microfluidic channel 221 may include an inlet 222 and an outlet 224 having at least a first flow branch 226 and a second flow branch 228.

[0092] The flow of fluid 208 and particles 210 in the fluid flow may be received at the inlet 222. Any particles 210 may be detected by particle sensors 112 positioned along the microfluidic channel 221 to provide signal data representative of signals corresponding to the fluid 208 and the particles 210 dispersed therein. The controller 110 may be operatively coupled to the particle sensors 112 to receive an indication that a particle 210 has been detected.

[0093] The controller 110 can be operably coupled to a flow routing element 230 positioned along at least one flow branch 226, 228 of the outlet 224. In the illustrated embodiment, the flow routing element 230 includes a single valve 232 positioned between the first flow branch 226 and the second flow branch 228 to selectively divert the fluid flow to one branch or the other. The controller 110 can be configured to control the flow routing element to direct the fluid flow to the first flow branch 226 until, for example, a threshold level of particles 210 is detected by a particle sensor 112 in the microfluidic channel 221. The controller 110 can also be configured to determine whether a threshold level of particles 210 is present in the microfluidic channel 221 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 221, the controller 110 can control the flow routing element 230 to direct the fluid flow to the second flow branch 228.

[0094] The threshold level of particles 210 may be determined in any suitable manner, including, but not limited to, detecting one or more particles above a threshold size, detecting a number of particles above a threshold number, detecting a threshold velocity (or frequency) of particles, or detecting a threshold concentration of particles in the fluid.

[0095] 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 timing to control the fluid routing element 230 to direct the fluid into the second flow branch 228 and the duration to control the fluid routing element to return the fluid to the first flow branch 226.

[0096] The flow routing element 230 may include one, two, or more valves 232, solenoids, or any other suitable mechanism for diverting the flow of 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 may alternately open and close to allow the fluid 208 to flow through the first flow branch 226 or the second flow branch 228.

[0097] Water droplet removal In some embodiments, configuration 220 can be represented as a water droplet removal system or 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 flow routing element 230, and a particle sensor 112 (e.g., optical or capacitive) that can detect individual water droplets in microfluidic channel 221. If microfluidic channel 221 contains water droplets, the fluid can be diverted to a waste stream, such as second flow branch 228, via a valve switch or other mechanism, such as valve 232. The waste stream can be sent to a waste collection area, a water removal filter (such as a barrier or coalescing filter), or returned to the main fuel tank. The time the fluid is diverted can be determined from the geometry of the microfluidic channel (such as dimensions and the length between the sensor and the diverter valve) and the flow rate. After the water droplets are sent to the waste stream, the diverter valve can be switched, and the fluid is sent to a main outlet, such as first flow branch 226. The main outlet is considered clean (eg, fuel without water droplets) and may be routed to a particulate filter, a high pressure common rail system, or another part of the fuel system.

[0098] In another configuration, the microfluidic droplet diverter may include two valves. One valve may be located in a main outlet channel, such as the first flow branch 226, and the other valve may be located in a waste outlet channel or the second flow branch 228. The valve may be located near the junction where the inlet flow channel, the waste outlet channel, and the main outlet channel meet, and thus may be integrated into the microfluidic device. Alternatively, the valve may be remote from the junction and separate from the microfluidic device (e.g., in tubing or piping exiting the device). When droplets are sensed by the droplet sensor, the main outlet valve may close and the waste outlet valve may open.

[0099] A diverter system may contain two or more microfluidic channels to increase total throughput. Multiple channels may or may not share the same particle sensor 112. A channel containing droplets can be detected by making the sensor output specific to that channel (see Figures 11A-B).

[0100] The diverter system can also be used with a fuel system with two parallel combining elements. When a water sensor positioned downstream of the first combining element detects water, one or more valves can switch flow from the first combining element to the second combining element. This allows the driver to switch filters at longer intervals or at more convenient times.

[0101] FIG. 8 is a conceptual diagram illustrating another example of a configuration 240 for using a particle sensor 112 with a microfluidic channel 241 of a hydrodynamic separator 260, sometimes referred to as a microfluidic separation channel. The microfluidic channel 241 may 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 hydrodynamic separator 260 is curved. The curvature may follow a circular shape. In other embodiments, the microfluidic channel 241 may be curved and have multiple S-shaped configurations. Any suitable curved shape may be used to provide sufficient inertial force to focus particles within a particular size range at a particular flow rate. The inlet 242 may be positioned at one end or end region, and the outlet 244 may be positioned at the opposite end or end region.

[0102] The hydrodynamic separator 260 can be designed such that, at a predetermined flow rate of the fluid 208, the microfluidic channel 241 is configured to direct particles 210 above a corresponding threshold size to the second flow branch 248 and direct the remaining particles to both the first flow branch 246 and the second flow branch 248 of the outlet 224.

[0103] The flow of fluid 208 and particles 210 in the flow of fluid may be received at the inlet 242. Any particles 210 may be detected by particle sensors 112 positioned along the microfluidic channel 241 to provide signal data representative of signals corresponding to the fluid 208 and the particles 210 dispersed therein. The controller 110 (FIG. 1) is operably coupled to the particle sensors 112 and may receive an indication that a particle 210 has been detected.

[0104] The controller 110 may be operably coupled to a fluid pump 114 ( FIG. 1 ) in fluid communication with the microfluidic channels 241 of the hydrodynamic separator 260. The fluid pump 114 may be configured to pass a fluid through the microfluidic channels 241 of one or more of the hydrodynamic separators 260. The controller 110 may be configured to control the fluid pump to flow the fluid through the hydrodynamic separation element from the inlet 242 to the outlet 244. The controller 110 may also be configured to determine whether a threshold level of particles 210 is present in the microfluidic channels 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 channels 241, the controller 110 may control the fluid pump 114 to pass the fluid 208 through the microfluidic channels of the hydrodynamic separator 260 at a predetermined flow rate to focus particles above a corresponding threshold size into a second flow branch 248.

[0105] The particle sensors 112 a, b may be positioned at any suitable location along the microfluidic channel 241. In some embodiments, the particle sensors 112 a, b may be positioned between the inlet 242 and the outlet 244. In some embodiments, the particle sensor 112 a may be positioned closer to the inlet 242. Nearer the inlet 242, particles 210 above a threshold size may be unfocused along the inner wall 262 of the hydrodynamic separator 260. The particle sensor 112 a may define a sensing region (schematically shown by 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. Nearer the outlet 244, particles 210 above a threshold size may be focused along the inner wall 262 of the hydrodynamic separator 260. The particle sensor 112b positioned toward the outlet 244 can define a sensing area (schematically shown by a solid line) covering some or less than half the width of the microfluidic channel 241 from the inner wall 262 to the outer wall 264.

[0106] Generally, when a droplet is sensed, the arrangement 240 can alter the fluid flow to focus the droplet into a waste stream. The flow may be calibrated to remove droplets or particles of a particular size based on sizing information from the particle sensors 112a,b. The flow can be altered by a pressure pulse, a dip, or a change in the flow path (such as opening or changing the valve position of one or more valves positioned at the outlet 244).

[0107] In some embodiments, the waste stream, such as second flow branch 248, may be only a fraction of the size of the overall flow stream, thereby minimizing the impact on the overall flow stream when removing droplets.

[0108] 9-10 are conceptual diagrams illustrating another configuration 300 for using the particle sensor 112, including a particle separation element 302 and a microfluidic sensing element 116. The configuration 300 can be used to sort particles 210 and calculate the number of particles in different size ranges. Although a two-stage separation element 302 is shown to separate particles into three size ranges, any suitable number of stages (n) can be used to separate particles into different size ranges (n+1 size ranges).

[0109] In the illustrated embodiment, the particle separation element 302 is configured to sort particles 210 within a first size range, a second size range, and a third size range into a first outlet stream 304 (comprising particles within the first size range, the second size range, and the third size range), a second outlet stream 306 (comprising particles within the second size range and the third size range), and a third outlet stream 308 (comprising particles within the third size range) for sensing by the microfluidic sensing element 116. A particle sensor 112 is positioned along the microfluidic sensing element 116 to detect the number of particles in each outlet stream 304, 306, 308. The controller 110 ( FIG. 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.

[0110] 10 , the particle separation element 302 may include at least a first hydrodynamic separator 320 and a second hydrodynamic separator 322. Each hydrodynamic separator 320, 322 may define a curved microfluidic channel for separating particles of different size ranges, which may also be referred to as a microfluidic separation channel. The outlet of the first hydrodynamic separator 320 may include a first flow branch 326 and a second flow branch 328. The outlet of the second hydrodynamic separator 322 may include a first flow branch 330 and a second flow branch 332.

[0111] The second flow branch 328 of the first hydrodynamic separator 320 may be configured to provide the first outlet stream 304. The second flow branch 332 of the second hydrodynamic separator 322 may be configured to provide the second outlet stream 306. The first flow branch 330 of the second hydrodynamic separator 322 may be configured to provide the third outlet stream 308. The first flow branch 326 of the first hydrodynamic separator 320 may be in fluid communication or fluidly coupled to an inlet of the second hydrodynamic separator 322 to provide the fourth fluid stream 310.

[0112] The first hydrodynamic separator 320 can be configured to focus all particles within a first size range into the second flow branch 328. The first size range can include any particles above a first threshold size. The 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 uniformly distributed. The ratio of the remaining particles provided to each branch 326, 328 can be determined based on the volume fraction associated with each branch 326, 328. Generally, the first flow branch 326 can accept a first portion of the remaining particles that do not exceed the first threshold size, and the second flow branch 328 can accept a second portion. As seen in FIG. 9 , the first outlet flow 304 from the second branch 328 contains particles of all size ranges. Neither of the other outlet flows 306, 308 contains particles above the first threshold size.

[0113] The second hydrodynamic separator 322 can receive a flow from the first branch 326 that includes a second portion of the remaining particles that do not exceed the first threshold size. The second hydrodynamic separator 322 can be configured to focus all particles within a second size range into the second flow branch 332. The second size range can include any particles that exceed the second threshold size. The 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, or can be only particles within a third size range. The remaining particles can be considered to be uniformly dispersed. The proportion of the remaining particles provided to each branch 330, 332 can be determined based on the volume fraction associated with each branch 330, 332. Generally, the first flow branch 330 can receive the first portion, and the second flow branch 332 can receive the second portion of the remaining particles that do not exceed the second threshold size. As can be seen in FIG. 9, the second outlet stream 306 contains particles of both particle size ranges that do not exceed the first threshold size, and the third outlet stream 308 contains only particles that do not exceed the second threshold size.

[0114] The microfluidic sensing element 116 can be in fluid communication with the particle separation element 302. The microfluidic sensing element 116 can include multiple microfluidic channels 340, sometimes referred to as microfluidic sensing channels, with each microfluidic channel 340 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 stream 304, 306, 308. The particle sensor 112 can be positioned and configured to detect the number of particles flowing through each microfluidic channel 340.

[0115] The controller 110 can determine the number of particles in each size range by counting the number of particles of any size range in each outlet stream 304, 306, 308 in the microfluidic channel 340. For illustrative purposes, assuming a 1:1 volume ratio between each pair of flow branches and the number of remaining particles (those not exceeding the particle threshold size) is divided equally between the two branches, the number of particles in each outlet stream can be calculated as follows:

number

[0116] Generally, the inlet of the particle separation element 302 can accept a random distribution of particles 210. The particle separation element 302 can sort the particles 210 into different outlet streams 304, 306, 308. The outlet streams 304, 306, 308 can be accepted 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 within each size range.

[0117] In some embodiments, the particle sensor 112 may include a detector aligned with each microfluidic channel 340 to count the number of particles in each channel. In other embodiments, the particle sensor 112 may use a shared detector across multiple channels to count the number of particles in each channel.

[0118] The configuration 300 can be described as a microfluidic particle sensor that can be used to measure fluid cleanliness levels in liquid applications. In one example, the microfluidic particle sensor can be used in a diesel fuel filtration system to measure fluid cleanliness. The sensor can be placed upstream of a filter, downstream of a filter, or as a bypass relative to a filter. The sensor can include a segmentation stage or particle separation element 302 that separates particles into streamlines, for example, based on ISO cleanliness codes. The streamlines can include particles 4-6 micrometers in a first stream, particles 6-14 micrometers in a second stream, and particles greater than 14 micrometers in a third stream. Particle sizes less than 4 micrometers can be omitted, or additional stages (e.g., four stages) can be added to capture particles less than 4 micrometers, 4-6 micrometers, 6-14 micrometers, and greater than 14 micrometers. The microfluidic particle sensor can also be used in hydraulic or lubrication applications.

[0119] The sensor can be described as having two stages. The first stage, sometimes called a "segregator stage," such as particle separation element 302, focuses particles into specific streamlines based on particle size. The second stage, sometimes called a "sensing stage," includes multiple sensing channels, such as microfluidic sensing element 116, where streamlines containing specific particles are routed to different channels. Each individual channel has a particle sensor or particle counter. The design of the segregator stage may dictate which particle size range falls in each channel. By counting or otherwise detecting particles in the sensing channels, the particle size distribution can be determined.

[0120] Once particles are focused into streamlines based on their particle size, the streamlines may be routed to different sensing channels, such as microfluidic channel 340. Each sensing channel corresponds to a particular particle size range (based on the design and performance of the segregator stage). Each sensing channel may be associated with a particle sensor. The particle sensor can detect or count the passage of particles through the sensing channel. The particle sensor can be optical (using absorbance, fluorescence, scattering, or other optical methods), electronic (using capacitance or impedance sensors), or magnetic. When the signal output from each channel is unique, the sensing channels can share a single particle sensor.

[0121] Such microfluidic particle sensors, which use a passive particle focusing scheme upstream of the particle counter, may not require calibration when particles are counted. This may facilitate manufacturing. Microfluidic particle sensors can also be designed to work with a variety of different types of particles with different properties, such as electronic or magnetic properties. Microfluidic particle sensors can also count individual particles one at a time instead of reading the bulk fluid, which may result in increased sensitivity. The use of microfluidic channels can also minimize the effects of background or carrier fluid.

[0122] 11A-B are conceptual diagrams illustrating one example of a technique for counting the number of particles in multiple microfluidic channels 340a, 340b, 340c using a shared photodetector, such as photodetector 206 (FIG. 6). Aperture element 350 may be similar to aperture element 218 (FIG. 6), except that aperture element 350 includes multiple apertures 204 aligned in each microfluidic channel 340a, 340b, 340c. Each set of apertures 204 can define a unique spacing pattern along the corresponding microfluidic sensing channel 340a, 340b, 340c. The unique spacing pattern may also be referred to as a unique orifice pattern.

[0123] The controller 110 (see FIG. 6 ) can be configured to determine signal data based on the signal 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 unique spacing patterns associated with the particles passed through the sensing region 216 based on the signal data. In particular, a particle passing through microfluidic sensing channel 340a may provide first unique signal data 342a, a particle passing through microfluidic sensing channel 340b may provide second unique signal data 342b, and a particle passing through microfluidic sensing channel 340c may provide third unique signal data 342c. Signal processing or pattern recognition processing by the controller 110 can be configured to distinguish these unique patterns and identify the corresponding microfluidic sensing channels 340a, 340b, 340c and the number of particles in the corresponding microfluidic sensing channels.

[0124] In general, a unique spacing pattern provides a different temporal profile for droplets traveling through a particular microfluidic sensing channel 340a, 340b, 340c. In the illustrated embodiment, a series of holes are positioned at different distances from each other, such that droplets traveling through the channel provide several signal dips, and the temporal pattern of the dips is unique to the channel. Orifice patterns that provide different signal profiles (such as orifice holes of different shapes) can also be used to create unique signals. Unique spacing and unique shapes can also be used in combination. When multiple droplets are present in a channel, signal deconvolution algorithms can be used to distinguish between individual channels.

[0125] In some embodiments, a diffraction grating can also be used to control the light entering the channel. The diffraction grating may be within or confined within the channel and can direct the light path to a specific detector in an array of detectors.

[0126] An understanding of various aspects of the present disclosure can be gained through a discussion of specific examples and exemplary embodiments provided below that provide particle separation to supplement or replace a filter. However, the present disclosure is not limited thereto. Various modifications of the examples and exemplary embodiments, as well as additional embodiments of the present disclosure, will become apparent herein.

[0127] 12 is a conceptual diagram illustrating one 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 hydrodynamic separator element, may be used in the fluid system 360 along a main flow line 362.

[0128] As shown, a fluid pump 114 may be used to provide a fluid flow from a fluid source 104 through a particle separation element 102 to a main flow line 362. The particle separation element 102 may 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 may be recombined along the main flow line 362 upstream of a fluid destination 106, which may include the remainder of the system 360.

[0129] The secondary outlet flow may be provided to a filter 366 along second flow branch 364 upstream of the recombination with the primary outlet flow. An optional filter 368 may be positioned upstream of the recombination, for example along first flow branch 363, or downstream of the recombination along primary flow line 362.

[0130] 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.

[0131] The particle separation element 102 can be configured to remove particles larger than a certain threshold size in diameter from the main flow line 362, and the fluid pump 114 provides the fuel at a certain flow rate.

[0132] The separator element 102 can be used to focus particles above a certain threshold size into a portion of the total fluid stream. The focused particle stream may be focused or directed along a second branch 364 into a secondary outlet stream that may be provided to a filter 366, sometimes referred to as a dead-end filter, for particle removal. After passing through the filter 366, the fluid from the focused particle stream from the second flow branch 364 may be combined with the remainder of the fluid from the first flow branch 363 and delivered to the remainder of the system, shown as the fluid destination 106. Particles above a critical size can be largely removed from the total fluid provided to the fluid destination 106.

[0133] In system 360, only a portion of the total fluid flow is filtered through filter 366. In some embodiments, the concentrated particle stream provided to second flow branch 364 may comprise 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, a system in which particle separation element 102 was not used. A lower flow rate may result in a lower filter pressure drop, a longer filter life, or both.

[0134] For example, an additional filter 368 can be used along the "clean stream" line along the first flow branch 363 or along the main flow line 362 after the fluid streamlines join to remove particles below a critical size. Flow metering or variable pressure objects can be used in the clean stream along the first flow branch 363 to properly balance the flow between the two streams exiting the separator element 102.

[0135] The technique for coupling the separator element 102 to a filter can be used in many applications, such as engine fuel, engine oil, engine hydraulics, and stationary hydraulics. This technique can be particularly useful in engine oil, engine hydraulics, or stationary hydraulics where the fluid is recirculated through a filter system. [Example]

[0136] Device fabrication In Example 1, a hydrodynamic separator was fabricated as a microfluidic device from polydimethylsiloxane (PDMS) using standard soft photolithography techniques. Briefly, a photomask was prepared using DraftSight and printed at 20,000 dpi (CAD / Art Services, Inc.; Brandon, Oregon). SU-8 2100 photoresist (MicroChem, Inc.; Newton, MA) was used to prepare an SU-8 mold. The process parameters are described in the SU-8 2100 data sheet provided by MicroChem. PDMS (Sylguard 184; Dow Corning; 10:1 w / w base:hardener) was poured into 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 with a biopsy needle. Particles and fibers were removed from the PDMS using Scotch tape. The final device was prepared by plasma bonding the PDMS to a glass slide using a Harrick Plasma cleaner at 800 mtorr for 1 minute. The completed device was placed on a hotplate at approximately 100°C for 15 minutes. Devices were designed with a constant radius of curvature, channel width, and channel depth.

[0137] Particle Imaging In Example 2, fluorescent particles were suspended in deionized water for testing (Table 1). 2, 10, and 20 micrometer (μm) particles were provided in aqueous suspension. These samples were diluted and tested directly.

[0138] The 25 μm and 30 μm particles were provided as powders, and these samples were added to deionized water along with sodium dodecyl sulfate surfactant (SDS) to prepare test solutions.

[0139] A typical mixture contained 50 mg of particles, 100 mg of SDS, and 500 mL of deionized water. Particle size distribution was confirmed with a laser diffraction particle sizer (Beckman-Coulter LS-320).

[0140] Particles were fed into a hydrodynamic separator formed according to Example 1 using a pressure-driven flow system (ElveFlow OB1-Mk3; Elvesys; Paris, France). The system included an in-line flow meter (Elveflow FS4 (0-1 mL / min) or FS5 (0.2-5 mL / min); Elvesys; Paris, France) to measure flow in real time. Flow could be controlled by pressure or flow rate within the ESI software package.

[0141] Particle focusing within the hydrodynamic separator was optically measured using an Olympus IX-73 inverted microscope (Olympus Life Science; Waltham, MA) coupled with a mercury vapor short-arc lamp (U-HGLGPS, Olympus Life Science; Waltham, MA). A fluorescence filter cube was selected to match the absorbance and emission characteristics of the fluorescent particles. Images were taken using a 10x objective. Images were captured using a Prime BSI sCMOS camera (Teledyne Photometrics; Tuscan, AZ) using MicroManager (version 1.4; https: / / micro-manager.org / wiki / Micro-Manager).

[0142] [Table 2]

[0143] Prior to particle injection, a pressure-flow calibration was determined for each hydrodynamic separator using deionized (DI) water to calibrate the unreliable flow meter readings for the particle-containing solution. The data were fitted to a second-order polynomial equation and used to determine the operating pressure for the desired experimental flow rate.

[0144] During particle experiments, the system pressure was controlled and pressure-flow data was recorded. If the pressure-flow data showed a decay over the experimental time frame, it was assumed that particles had collected somewhere in the device and no data was recorded.

[0145] After the experiment, the devices were cut in half and the channel depth was optically measured with a Keyence VHX digital microscope (Keyence; Itasca, IL).

[0146] After the pressure-flow relationship of the device was calibrated, experiments were performed at a constant Dean number or flow rate using a single fluorescent particle solution. c To measure particle focusing as α = α, where α is the angle through the device in radians and R is the radius of curvature measured at the inner wall, fluorescence images were taken at various angles through the device. Angles were defined around the circular shape of each hydrodynamic separator, as shown, for example, in Figure 14. Figure 14 is a conceptual diagram showing the relative positions of angles around a hydrodynamic separator 400 at the inlet (A), 180° (B), 270° (C), and outlet (D) at 350°. The integration time of the cMOS camera was set to maximize signal difference without saturating the pixels.

[0147] The degree of particle focusing was determined using image analysis with ImageJ open-source software. Pixel intensity was measured across the channel at each imaging location on the device. Pixel intensity is assumed to be proportional to the average particle concentration. The location of particle focusing was determined from the exit image (340° or 350°). For each image, the focusing ratio was determined as the ratio of the integrated pixel intensity at the focused region to the integrated pixel intensity across the channel:

number

[0148] 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 a plot 390 of pixel intensity versus channel position (in pixels) across the channel indicated by line 384 in Figure 13A. Figure 13D is a plot 392 of pixel intensity versus channel position (in pixels) across the channel indicated by line 386 in Figure 13B. Boxes 394, 396 were considered focal regions.

[0149] Focusing study: same device, different Dean numbers (140 μm depth: 25 μm particles) In Example 3, 25 μm particles were focused in a hydrodynamic separator (channel width: 500 μm, channel depth: 140 μm, radius of curvature: 20 mm) at two Dean numbers. A plot 410 showing the focusing ratio versus channel length data for a Dean number of 15 at a pressure of 1010 mbar (3.97 mL / min) is shown in FIG. 15. Plot 410 shows three distinct regions: an initial region 412 where the particles are unfocused, a region 414 where the particles are focused, and a region 416 where the particles are fully focused.

[0150] At the device inlet, particles are approximately 35% focused. Over the first 14 mm of channel length, the amount of focusing does not increase. This may be due to particle migration from the center of the channel to the channel edges due to shear lift forces. This region 412 of the device, sometimes referred to as the particle migration region, has a length L0. This length may depend on particle size, fluid properties, and flow rate.

[0151] After the particle transfer region, the fraction of particles that are focused may increase linearly with channel length. This region 414 of the device is sometimes called the linear focusing region. The slope of the line fit is the linear focusing rate (r f ), the fraction of particles that are focused typically increases linearly up to a maximum value.

[0152] Once the maximum particle focusing is reached, the particle focusing may remain approximately constant. This region 416 of the device is sometimes referred to as the fully focused region. In this example, the maximum focusing ratio (f m ) is about 90% (i.e., 90% of the particles are focused).

[0153] The length of the hydrodynamic separator that can be used to reach the target focusing ratio can be expressed as:

number

[0154] Table 3 shows data for focusing experiments performed with the same device but at different Dean numbers. The length of the particle movement region and the length required to reach 90% focusing are similar and nearly identical.

[0155] [Table 3]

[0156] Experiments with the same Dean number, different devices (104 μm depth: 30 μm particle) In Example 4, an experiment similar to that in Example 3 was performed with devices having approximately the same Dean number but two different radii of curvature. 30 μm particles were used. The results of the experiment are shown in Table 4. The length of the particle movement region was shorter in the device with the smaller radius of curvature. Furthermore, the linear focusing ratio was higher in the device with the smaller radius of curvature. Based on these results, for example, the length required to focus particles to 50% was shorter in the device with the smaller radius of curvature.

[0157] [Table 4]

[0158] In general, devices with smaller radii of curvature may achieve a target Dean number at a lower flow rate than devices with larger radii of curvature. When comparing the pressure drop required to focus particles, a smaller radius of curvature may result in shorter channels and lower flow rates, which can have a significant impact on the pressure drop.

[0159] As an example, from the data in Table 4 and the experimental pressures applied, the pressure drop associated with a hydrodynamic separator designed to focus 50% of the particles was calculated from the following equation:

number

number

[0160] Length of the linear focusing region Recently, it has been discovered that the length of the linear focusing region required to achieve maximum particle focusing (85% to 95% particle focusing) can be expressed by the following relationship:

number

number

[0161] Furthermore, the length of the linear focusing region required to achieve maximum particle focusing for a particular particle size can be expressed by the following relationship:

number

[0162] The overall length of the hydrodynamic separator can be determined or calculated as follows: L D =L0+L f (Formula 13)

[0163] This formula can be used to calculate the minimum hydrodynamic separator channel length required to achieve maximum particle focusing for various applications. Experimental results show that the particle migration region length L0 is proportional to the hydrodynamic separator L required to achieve maximum particle focusing. DFurthermore, the data show that the length of the particle transport region, L0, is in the range of 0% to 29% of the total length of the linear focusing region, L f It has been shown that the length of the hydrodynamic separator channel, L, is in the range of 0% to 40% of the length of the separator channel. Therefore, to achieve maximum particle focusing, the length of the hydrodynamic separator channel, L, D the linear focusing region L f The hydrodynamic separator channel length L D is the linear focusing region L to achieve particle focusing balanced with minimizing the pressure drop across the channel. f may be no more than 40% longer than the length of the

[0164] Exemplary Embodiments Some embodiments relate to a hydrodynamic separator.

[0165] In embodiment A1, the system: A hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel in fluid communication, each microfluidic channel comprising: an inlet configured to receive a fluid and particles dispersed in the fluid, the particles having a different composition than the fluid; an outlet having a first flow branch and a second flow branch; Define the a hydrodynamic separation element configured such that, at a predetermined flow rate, each microfluidic channel directs any particles above a corresponding threshold size to the second flow branch and any remaining particles to both the first flow branch and the second flow branch; a particle sensor positioned along the one or more hydrodynamic separators and configured to provide signal data representative of the fluid and a signal corresponding to particles in the fluid; a controller operably coupled to the particle sensor to receive the signal data, the controller being operably coupled to the fluid pump in fluid communication with the hydrodynamic separation element, the controller comprising: controlling a fluid pump to pass a fluid through the hydrodynamic separation element; determining whether a threshold level of particles is present in the at least one microfluidic channel based on the signal data from the particle sensor; a controller configured to, in response to determining that a threshold level of particles is present in the at least one microfluidic channel, control a flow rate through the hydrodynamic separation element to pass fluid through the hydrodynamic separation element at a predetermined flow rate and to focus any particles above a corresponding threshold size into a second flow branch of the at least one microfluidic channel; Equipped with.

[0166] In embodiment A2, the system comprises a particle sensor comprising: a light source configured to direct a beam of light within a frequency band along a path through the at least one hydrodynamic separator, the frequency band being selected such that absorbance by the particles differs from absorbance by the fluid; an aperture element defining an optical aperture positioned in the path of the light beam from the light source; a photodetector positioned to receive the light beam at a sensing region after passing through the at least one hydrodynamic separator and the optical aperture, the photodetector configured to provide signal data representative of the amount of light within the frequency band remaining after passing through the at least one hydrodynamic separator; The system of embodiment A1 includes:

[0167] In embodiment A3, the system includes the system of embodiment A1, in which the particle sensor comprises a capacitance sensor.

[0168] In embodiment A4, the system includes any one of the above A embodiments, further comprising a source reservoir in fluid communication with the inlet and the second flow branch, and capable of pumping fluid and particles from the source reservoir to the hydrodynamic separation element and selectively back to the source reservoir through the second flow branch.

[0169] Some embodiments relate to particle diverters.

[0170] In embodiment B1, the system A particle separation element comprising one or more microfluidic channels in parallel fluid communication, each microfluidic channel comprising: an inlet configured to receive a fluid and particles dispersed in the fluid, the particles having a different composition than the fluid; a particle separation element defining a first flow branch and an outlet having a second flow branch; a flow routing element positioned along at least one flow branch of the at least one outlet; a particle sensor positioned along one or more microfluidic channels and configured to provide signal data representative of a fluid and a signal corresponding to particles dispersed in the fluid; a controller operably coupled to the at least one flow routing element and operably coupled to the particle sensor to receive signal data, controlling the flow routing element to direct the fluid flow into a first flow branch of the at least one outlet of the at least one microfluidic channel; determining whether a threshold level of particles is present in the at least one microfluidic channel based on the signal data from the particle sensor; a controller configured to control the flow routing element to direct the fluid flow into a second flow branch of the at least one microfluidic channel in response to determining that a threshold level of particles is present in the at least one microfluidic channel; Equipped with.

[0171] In embodiment B2, the system includes the system described in embodiment B1, wherein the particle separation element comprises a hydrodynamic separator element comprising one or more hydrodynamic separators, the one or more hydrodynamic separators comprising one or more microfluidic channels, each microfluidic channel being curved.

[0172] In embodiment B3, the particle sensor comprises: a light source configured to direct a beam of light within a frequency band along a path through at least one microfluidic channel, the frequency band being selected such that absorbance by the particles differs from absorbance by the fluid; an aperture element defining an optical aperture positioned in the path of the light beam from the light source; a photodetector positioned to receive the light beam within the sensing region after passing through the at least one microfluidic channel and the optical aperture, the photodetector configured to provide signal data representative of the amount of light within the frequency band remaining after passing through the at least one microfluidic channel; The system of embodiment B1 or B2 includes:

[0173] In embodiment B4, the system includes the system of embodiment B1 or B2, wherein the particle sensor comprises a capacitance sensor.

[0174] In embodiment B5, the system includes a system described in any one of the above B embodiments, further comprising a source reservoir in fluid communication with the inlet and the second flow branch, and capable of pumping fluid and particles from the source reservoir to the hydrodynamic separation element and selectively back to the source reservoir through the second flow branch.

[0175] Some embodiments relate to a particle classifier.

[0176] In embodiment C1, the system 1. A hydrodynamic separation element comprising a plurality of hydrodynamic separators in serial fluid communication, including at least a first hydrodynamic separator and a second hydrodynamic separator, each defining a curved microfluidic separation channel for separating particles of different size ranges, wherein each microfluidic separation channel comprises: an inlet configured to receive a fluid containing particles; an outlet having a first flow branch and a second flow branch; Define the a hydrodynamic separation element configured such that, at a particular flow rate, each microfluidic separation channel directs any particles above a corresponding threshold size to a second flow branch and any remaining particles to both the first flow branch and the second flow branch, the first flow branch of the first hydrodynamic separator being in fluid communication with an inlet of the second hydrodynamic separator; A microfluidic sensing element in fluid communication with the hydrodynamic separation element, the microfluidic sensing element comprising a plurality of microfluidic sensing channels each in fluid communication with a different flow branch of the hydrodynamic separation element, the plurality of microfluidic sensing channels comprising at least: a first microfluidic sensing channel in fluid communication with the second flow branch of the first hydrodynamic separator for accepting any particles above a first threshold size; a microfluidic sensing element comprising: a second microfluidic sensing channel in fluid communication with the second flow branch of the second hydrodynamic separator for accepting any particles above a second threshold size, the second microfluidic sensing channel having a first threshold size greater than the second threshold size; Equipped with.

[0177] In embodiment C2, the system includes the system of embodiment C1, wherein the plurality of microfluidic separation channels comprises a third hydrodynamic separator in fluid communication with the first flow branch of the second hydrodynamic separator.

[0178] In embodiment C3, the system comprises: particle sensors positioned along the plurality of microfluidic sensing channels and configured to provide signal data representative of signals corresponding to particles in the fluid; a controller operably coupled to the particle sensor to receive the signal data, the controller configured to determine, based on the signal data, a number of particles associated with each size range based on a volume fraction associated with the flow branch; The system of embodiment C1 or C2 further comprises:

[0179] In embodiment C4, the system includes the system described in embodiment C3, wherein at least one microfluidic separation channel has an outlet having a first outlet branch and a second outlet branch, and further comprises at least one flow routing element positioned along the outlet of the at least one microfluidic sensing channel, and the control device is operably coupled to the at least one flow routing element and further configured to control the at least one flow routing element to direct fluid flow to the second outlet branch in response to detection of a particle in the corresponding microfluidic sensing channel.

[0180] In embodiment C5, the system includes the system of embodiment C3 or C4, wherein the particle sensor includes a capacitance sensor.

[0181] In embodiment C6, the system comprises a particle sensor: a light source configured to direct a beam of light within a frequency band along a path through at least one microfluidic sensing channel, the frequency band being selected such that absorbance by the particles differs from absorbance by the fluid; an aperture element defining an optical aperture positioned in the path of the light beam from the light source; a photodetector positioned to receive the light beam within the sensing region after passing through the optical aperture and the at least one microfluidic sensing channel, the photodetector configured to provide signal data representative of the amount of light within the frequency band remaining after passing through the at least one microfluidic sensing channel; The system of any one of embodiments C3 to C4 includes:

[0182] In embodiment C7, the system is a system described in embodiment C6, wherein the aperture element comprises a plurality of optical apertures including an optical aperture positioned in the path of a light beam from the light source, the plurality of optical apertures comprising different sets of optical apertures arranged in each microfluidic sensing channel, each set of optical apertures defining a unique spacing pattern along the corresponding microfluidic sensing channel, the optical detector is positioned to receive the light beam at the sensing region after passing through the plurality of optical apertures and the plurality of microfluidic sensing channels, and the control device is configured to determine the number of particles associated with each size range based on the unique spacing pattern.

[0183] Some embodiments relate to an orifice pattern.

[0184] In embodiment D1, the system: a plurality of microfluidic sensing channels each configured to receive a flow of a fluid and particles dispersed in the fluid, the particles having a different composition than the fluid; a light source configured to direct a beam of light within a frequency band along a path through a plurality of microfluidic sensing channels, the frequency band being selected such that absorbance by the particles differs from absorbance by the fluid; an aperture element defining a plurality of optical apertures with a different set of optical apertures aligned with each microfluidic sensing channel, each set of optical apertures defining a unique spacing pattern along a corresponding microfluidic sensing channel; a photodetector positioned to receive the light beam at a sensing region after passing through the plurality of optical apertures of the aperture element and the plurality of microfluidic sensing channels, the photodetector configured to provide a signal representative of the amount of light within the frequency band remaining after passing through the plurality of microfluidic sensing channels; operatively coupled to the photodetector; determining signal data based on the signal from the photodetector; determining whether the particle has passed through the sensing region based on the signal data; a controller configured to determine a unique spacing pattern associated with particles passed through the sensing region based on the signal data; Equipped with.

[0185] In embodiment D2, the system includes the system described in embodiment D1, wherein each microfluidic sensing channel is configured to accept particles within a different size range, and the control device is further configured to determine the number of particles associated with each size range.

[0186] In embodiment D3, the system further comprises a hydrodynamic separation element positioned upstream of the plurality of microfluidic sensing channels, the hydrodynamic separation element comprising a plurality of hydrodynamic separators in serial fluid communication, including at least a first hydrodynamic separator and a second hydrodynamic separator, each defining a curved microfluidic separation channel for separating particles of different size ranges, each microfluidic separation channel comprising: an inlet configured to receive a fluid and particles dispersed in the fluid; an outlet having a first flow branch and a second flow branch; Define the at a particular flow rate, each microfluidic separation channel is configured to direct any particles above a corresponding threshold size to the second flow branch and any remaining particles to both the first flow branch and the second flow branch, and the first flow branch of the first hydrodynamic separator is in fluid communication with the inlet of the second hydrodynamic separator; The system includes the system of embodiment D1 or D2.

[0187] In embodiment D4, the system includes the system described in embodiment D3, wherein the controller is further configured to determine the number of particles associated with each size range based on the volume fraction associated with the flow branch based on the signal data.

[0188] In embodiment D5, the system includes the system described in embodiment D3 or D4, wherein the control device is operably coupled to a fluid pump in fluid communication with the hydrodynamic separation element, and the control device is configured to control the fluid pump to pass fluid through the hydrodynamic separation element at a specific flow rate.

[0189] In embodiment D6, the system includes a system described in any one of embodiments D3 to D5, wherein at least one microfluidic sensing channel has an outlet having a first outlet branch and a second outlet branch, and further comprises at least one flow routing element positioned along the outlet of the at least one microfluidic sensing channel, and wherein the control device is operably coupled to the at least one flow routing element and is further configured to control the flow routing element to direct the fluid flow toward the second outlet branch in response to detection of a particle in the corresponding microfluidic sensing channel.

[0190] Some embodiments relate to detecting water droplets.

[0191] In embodiment E1, the system includes the system of any A embodiment, any B embodiment, any one of embodiments C4-C8, or any D embodiment, wherein the particles comprise a second fluid different from the fluid.

[0192] In embodiment E2, the system includes the system of embodiment E1, wherein the controller is further configured to determine, based on the signal data, an amount of the second fluid in droplet form per unit volume of the fluid.

[0193] In embodiment E3, the system includes the system of embodiment E2, in which the amount excludes a second fluid dissolved in the fluid.

[0194] In embodiment E4, the system includes a system described in any one of the above E embodiments, wherein the control device is configured to determine, based on the signal data, a droplet velocity or droplet size of one or more droplets of a second fluid dispersed in the fluid stream.

[0195] In embodiment E5, the system further comprises a control device The magnitude of the pulse contained in the signal data, The width of the pulse contained in the signal data, a first threshold signal level for detecting a minimum size droplet within the sensing area; a second threshold signal level for detecting a droplet filling the sensing area; Threshold signal level crossing rate and The system of embodiment E4 is configured to determine droplet velocity or droplet size based on at least one of:

[0196] In embodiment E6, the system further comprises a control device: determining an amount of the second fluid in droplet form per unit volume of the fluid based on the droplet velocity and droplet size; responsive to the signal not exceeding a second threshold signal level, determining a droplet size based on the magnitude of a pulse contained in the signal data; determining a droplet size based on a width of a pulse included in the signal data in response to the signal exceeding a second threshold signal level; and Determining droplet size based on droplet velocity The system of embodiment E5 is further configured to perform at least one of the following:

[0197] In embodiment E7, the system comprises the system of any one of the above E embodiments, wherein the fluid comprises a hydrocarbon fluid and the second fluid comprises water.

[0198] Some embodiments relate to an engine fuel system.

[0199] In embodiment F1, the system comprises: a fuel line configured to deliver fuel to the fuel injector system; 1. A hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel for separating particles in a fuel, wherein each microfluidic channel comprises: an inlet in fluid communication with the fuel line for receiving fuel; a hydrodynamic separation element defining a first flow branch in fluid communication with the fuel line to supply fuel to the fuel injector system, and an outlet having a second flow branch for receiving particles within a specified size range; Equipped with.

[0200] In embodiment F2, the system includes the system of embodiment F1, wherein the particles include water droplets dispersed in the fuel.

[0201] In embodiment F3, the system includes the system of embodiment F1 or F2, further comprising a fuel tank in fluid communication with each inlet and in fluid communication with each second flow branch.

[0202] In embodiment F4, the system includes the system of any one of the above F embodiments, further including a fuel filter configured to filter particles from the gasoline or diesel fuel positioned along the fuel line.

[0203] In embodiment F5, the system includes the system of any one of the above F embodiments, further comprising a fuel pump in fluid communication with the fuel line, the fuel pump configured to provide fuel flow along the fuel line to a fuel injector system, and the fuel injector system comprising a high-pressure common rail.

[0204] Some embodiments relate to a bulk fuel system.

[0205] In embodiment G1, the system comprises: a fuel line configured to deliver fuel from the bulk fuel storage tank to the vehicle fuel tank; 1. A hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel for separating particles in a fuel, wherein each microfluidic channel comprises: an inlet in fluid communication with the fuel line for receiving fuel; a hydrodynamic separation element defining a first flow branch in fluid communication with a fuel line for supplying fuel to a vehicle fuel tank, and an outlet having a second flow branch for receiving particles within a specified size range; Equipped with.

[0206] In embodiment G2, the system includes the system of embodiment G1, further comprising a bulk fuel storage tank for storing fuel in fluid communication with the inlet and optionally in fluid communication with the second flow branch.

[0207] In embodiment G3, the system includes the system of embodiment G1 or G2, further comprising a secondary storage tank for storing fuel, in fluid communication with the second flow branch.

[0208] In embodiment G4, the system includes the system of any one of the above G embodiments, further comprising a fuel filter configured to filter particles from the gasoline or diesel fuel positioned along the fuel line.

[0209] In embodiment G5, the system includes the system of any one of the above G embodiments, further comprising a fuel pump in fluid communication with the fuel line, the fuel pump configured to provide a flow of fuel along the fuel line to the vehicle fuel tank.

[0210] Some embodiments relate to a hydraulic particulate filter.

[0211] In embodiment H1, the system: a hydraulic fluid line configured to deliver hydraulic fluid from the hydraulic pump to the hydraulic component; 1. A hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel for separating particles in a hydraulic fluid, wherein each microfluidic channel comprises: an inlet in fluid communication with the hydraulic fluid line for receiving hydraulic fluid from the hydraulic pump; an outlet in fluid communication with the hydraulic fluid line, the outlet having a first flow branch for providing hydraulic fluid to the hydraulic component and a second flow branch for accepting particles within a specified size range; a hydrodynamic separation element defining Equipped with.

[0212] In embodiment H2, the system includes the system of embodiment H1, further including a hydraulic fluid filter positioned along the hydraulic fluid return line in fluid communication between the second flow branch and the hydraulic fluid reservoir for filtering particles from the hydraulic fluid, the hydraulic fluid reservoir being in fluid communication with the inlet of the hydraulic pump.

[0213] Some embodiments relate to improved hydraulic degassing.

[0214] In embodiment I1, the system comprises: a hydraulic fluid return line configured to deliver hydraulic fluid from the hydraulic component to the hydraulic pump; 1. A hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel for separating particles in a hydraulic fluid, wherein each microfluidic channel comprises: an inlet in fluid communication with the hydraulic fluid line for receiving hydraulic fluid from the hydraulic pump; an outlet in fluid communication with the hydraulic fluid line, the outlet having a first flow branch for providing hydraulic fluid to the hydraulic pump and a second flow branch for accepting particles within a specified size range; a hydrodynamic separation element defining Equipped with.

[0215] In embodiment I2, the system comprises the system of embodiment I1, wherein the particles comprise gas bubbles.

[0216] In embodiment 13, the system includes the system of embodiment 12, further including a nucleation filter in fluid communication between the hydraulic component and the inlet for nucleating gas bubbles in the hydraulic fluid.

[0217] In embodiment I4, the system comprises: a main reservoir in fluid communication between the first flow branch and the hydraulic pump; a settling reservoir in fluid communication between the second flow branch and the main reservoir; The system of embodiment I3 further comprises:

[0218] Various embodiments of systems and methods for separating particles in hydrocarbon fluids have been disclosed. Reference is made herein to a series of accompanying drawings that form a part of this disclosure. Those skilled in the art will recognize that various adaptations and modifications of the embodiments described herein are within the scope of, or do not depart from, the present disclosure. For example, aspects of the embodiments described herein can be combined with each other in various ways. It is therefore to be understood that within the scope of the appended claims, the claimed invention may be practiced other than as expressly described herein.

[0219] All references and publications cited herein are incorporated by reference in their entirety for all purposes, except to the extent that any aspect directly contradicts this disclosure.

[0220] All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are intended to facilitate understanding of certain terms used frequently herein and are not meant to limit the scope of the present disclosure.

[0221] Unless otherwise specified, all numbers expressing size, quantity, and physical properties of features used in the specification and claims can be understood to be modified by either the term "exactly" or "about." Accordingly, unless otherwise indicated, the numerical parameters set forth in the foregoing specification and appended claims are approximations that can vary depending upon the desired properties sought to be obtained by those of ordinary skill in the art utilizing the teachings disclosed herein, or within typical ranges of experimental error, for example.

[0222] The recitation of numerical ranges by endpoints includes all numbers subsumed within that range and any range within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). As used herein, the terms "up to" or "less than or equal to" a number (e.g., up to 50) include that number (e.g., 50), and the term "greater than or equal to" a number (e.g., 5 or greater) includes that number (e.g., 5).

[0223] Orientation-related terms such as "upstream" and "downstream" are used to describe the relative positions of components and are not intended to limit the absolute orientation of contemplated embodiments.

[0224] The terms "coupled" or "connected" refer to elements that are attached to one another either directly (in direct contact with one another) or indirectly (having one or more elements between and connecting the two elements). Both terms may be modified by "operably" and "operably," which may be used interchangeably, and refer to a coupling or connection that allows the components to interact to perform a function.

[0225] As used herein, the term "configured" may be used interchangeably with the terms "adapted" or "structured," unless the context of this disclosure makes clear otherwise.

[0226] The term "or" is generally employed in its inclusive sense, i.e., meaning "and / or," unless the context clearly indicates otherwise. The term "and / or" refers to one or all of the listed elements or a combination of at least two of the listed elements.

[0227] The phrases "at least one of," "comprising at least one of," and "one or more of" following a list refer to any one of the items in the list and any combination of two or more items in the list.

Claims

1. A hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel in fluid communication, each microfluidic channel comprising: an inlet configured to receive a first fluid and particles dispersed in the first fluid, the particles having a different composition than the first fluid; an outlet having a first flow branch and a second flow branch; Define the a hydrodynamic separation element configured such that, at a predetermined flow rate, each microfluidic channel directs any particles above a corresponding threshold size to the second flow branch and any remaining particles to both the first flow branch and the second flow branch; a particle sensor positioned along the one or more hydrodynamic separators and configured to provide signal data representative of the first fluid and a signal corresponding to the particles in the first fluid; a controller operably coupled to the particle sensor to receive the signal data, the controller being operably coupled to a fluid pump in fluid communication with the hydrodynamic separation element, controlling the fluid pump to pass the first fluid through the hydrodynamic separation element; determining whether a threshold level of particles is present in at least one microfluidic channel based on the signal data from the particle sensor; a controller configured to, in response to determining that the threshold level of particles is present in the at least one microfluidic channel, control a flow rate through the hydrodynamic separation element to pass the first fluid through the hydrodynamic separation element at the predetermined flow rate and to focus any particles above the corresponding threshold size into the second flow branch of the at least one microfluidic channel; A system comprising:

2. The particle sensor a light source configured to direct a beam of light within a frequency band along a path through at least one hydrodynamic separator, the frequency band being selected such that absorbance by the particles differs from absorbance by the first fluid; an aperture element defining an optical aperture positioned in the path of the light beam from the light source; a photodetector positioned to receive the light beam at a sensing region after passing through the at least one hydrodynamic separator and the optical aperture, the photodetector configured to provide the signal data indicative of an amount of light within the frequency band remaining after passing through the at least one hydrodynamic separator; The system of claim 1 , comprising:

3. The system of claim 1 , wherein the particle sensor comprises a capacitance sensor.

4. 4. The system of claim 1, further comprising a source reservoir in fluid communication with the inlet and a second flow branch, wherein the first fluid and the particles can be pumped from the source reservoir to the hydrodynamic separation element and selectively back to the source reservoir through the second flow branch.

5. The system of any one of claims 1 to 4, wherein the particles comprise a second fluid different from the first fluid.

6. The system of claim 5 , wherein the controller is further configured to determine an amount of the second fluid in droplet form per unit volume of the first fluid based on the signal data.

7. The system of claim 6 , wherein the amount excludes the second fluid dissolved in the first fluid.

8. 8. The system of claim 5, wherein the controller is configured to determine a droplet velocity or a droplet size of one or more droplets of the second fluid dispersed in the stream of the first fluid based on the signal data.

9. The control device The magnitude of a pulse included in the signal data; a pulse width included in the signal data; and a first threshold signal level for detecting a minimum size droplet within the sensing area; a second threshold signal level for detecting a droplet filling the sensing area; Threshold signal level crossing rate and The system of claim 8 , configured to determine the droplet velocity or the droplet size based on at least one of:

10. The control device determining an amount of a second fluid in droplet form per unit volume of the first fluid based on the droplet velocity and droplet size; responsive to the signal not exceeding the second threshold signal level, determining the droplet size based on the magnitude of pulses included in the signal data; determining the droplet size based on the width of a pulse included in the signal data in response to the signal exceeding the second threshold signal level; and determining the droplet size based on the droplet rate; The system of claim 9 , further configured to perform at least one of:

11. The system of any one of claims 5 to 10, wherein the first fluid comprises a hydrocarbon fluid and the second fluid comprises water.

12. A particle separation element comprising one or more microfluidic channels in parallel fluid communication, each microfluidic channel comprising: an inlet configured to receive a first fluid and particles dispersed in the first fluid, the particles having a different composition than the first fluid; an outlet having a first flow branch and a second flow branch; a particle separation element defining a flow routing element positioned along at least one flow branch of the at least one outlet; a particle sensor positioned along the one or more microfluidic channels and configured to provide signal data representative of the first fluid and a signal corresponding to the particles dispersed in the first fluid; a controller operably coupled to the flow routing element and operably coupled to the particle sensor to receive the signal data, controlling the flow routing element to direct fluid flow into the first flow branch of the at least one outlet of at least one microfluidic channel; determining whether a threshold level of particles is present in at least one microfluidic channel based on the signal data from the particle sensor; In response to determining that the threshold level of particles is present in the at least one microfluidic channel, controlling the flow routing element to direct fluid flow into the second flow branch of the at least one microfluidic channel. A control device configured as above, A system comprising:

13. 13. The system of claim 12, wherein the particle separation element comprises a hydrodynamic separator element including one or more hydrodynamic separators, the one or more hydrodynamic separators comprising the one or more microfluidic channels, each microfluidic channel being curved.

14. The particle sensor a light source configured to direct a beam of light within a frequency band along a path through at least one microfluidic channel, the frequency band being selected such that absorbance by the particles differs from absorbance by the first fluid; an aperture element defining an optical aperture positioned in the path of the light beam from the light source; a photodetector positioned to receive the light beam within a sensing region after passing through the at least one microfluidic channel and the optical aperture, the photodetector configured to provide the signal data representative of an amount of light within the frequency band remaining after passing through the at least one microfluidic channel; 14. The system according to claim 12 or 13, comprising:

15. 14. The system of claim 12 or 13, wherein the particle sensor comprises a capacitance sensor.

16. 16. The system of any one of claims 12 to 15, further comprising a source reservoir in fluid communication with the inlet and a second flow branch, wherein the first fluid and the particles can be pumped from the source reservoir to the separation element and selectively back to the source reservoir through the second flow branch.

17. The system of any one of claims 12 to 16, wherein the particles comprise a second fluid different from the first fluid.

18. 20. The system of claim 17, wherein the controller is further configured to determine an amount of the second fluid in droplet form per unit volume of the first fluid based on the signal data.

19. 20. The system of claim 18, wherein the amount excludes the second fluid dissolved in the first fluid.

20. 20. The system of claim 17, wherein the controller is configured to determine a droplet velocity or a droplet size of one or more droplets of the second fluid dispersed in the stream of the first fluid based on the signal data.

21. The control device The magnitude of a pulse included in the signal data; a pulse width included in the signal data; and a first threshold signal level for detecting a minimum size droplet within the sensing area; a second threshold signal level for detecting a droplet filling the sensing area; Threshold signal level crossing rate and The system of claim 20 , configured to determine the droplet velocity or the droplet size based on at least one of:

22. The control device determining an amount of a second fluid in droplet form per unit volume of the first fluid based on the droplet velocity and droplet size; responsive to the signal not exceeding the second threshold signal level, determining the droplet size based on the magnitude of pulses included in the signal data; determining the droplet size based on the width of a pulse included in the signal data in response to the signal exceeding the second threshold signal level; and determining a droplet size based on said droplet rate; 22. The system of claim 21, further configured to perform at least one of:

23. The system of any one of claims 17 to 22, wherein the first fluid comprises a hydrocarbon fluid and the second fluid comprises water.

24. 1. A hydrodynamic separation element comprising a plurality of hydrodynamic separators in serial fluid communication, including at least a first hydrodynamic separator and a second hydrodynamic separator, each defining a curved microfluidic separation channel for separating particles of different size ranges, wherein each microfluidic separation channel comprises: an inlet configured to receive a first fluid containing particles; an outlet having a first flow branch and a second flow branch; Define the a hydrodynamic separation element, wherein at a particular flow rate, each microfluidic separation channel is configured to direct any particles above a corresponding threshold size to the second flow branch and any remaining particles to both the first flow branch and the second flow branch, the first flow branch of the first hydrodynamic separator being in fluid communication with the inlet of the second hydrodynamic separator; a microfluidic sensing element in fluid communication with the hydrodynamic separation element, the microfluidic sensing element comprising a plurality of microfluidic sensing channels each in fluid communication with a different flow branch of the hydrodynamic separation element, the plurality of microfluidic sensing channels comprising at least: a first microfluidic sensing channel in fluid communication with the second flow branch of the first hydrodynamic separator for receiving any particles above a first threshold size; a microfluidic sensing element comprising: a second microfluidic sensing channel in fluid communication with the second flow branch of the second hydrodynamic separator for accepting any particles above a second threshold size, the first threshold size being greater than the second threshold size; and A system comprising:

25. 25. The system of claim 24, wherein the plurality of microfluidic sensing channels comprises a third hydrodynamic separator in fluid communication with the first flow branch of the second hydrodynamic separator.

26. a particle sensor positioned along the plurality of microfluidic sensing channels and configured to provide signal data representative of a signal corresponding to the particles in the first fluid; a controller operably coupled to the particle sensor to receive the signal data, the controller configured to determine, based on the signal data, the number of particles associated with each size range based on a volume fraction associated with each flow branch; 26. The system of claim 24 or 25, further comprising:

27. 27. The system of claim 26, wherein at least one microfluidic separation channel comprises an outlet comprising a first outlet branch and a second outlet branch, and further comprises at least one flow routing element positioned along the outlet of at least one microfluidic sensing channel, wherein the control device is operably coupled to the at least one flow routing element and is further configured to control the at least one flow routing element to direct fluid flow to the second outlet branch in response to detection of a particle in a corresponding microfluidic sensing channel.

28. 28. The system of claim 26 or 27, wherein the particle sensor comprises a capacitance sensor.

29. The particle sensor a light source configured to direct a beam of light within a frequency band along a path through at least one microfluidic sensing channel, the frequency band selected such that absorbance by the particles differs from absorbance by the first fluid; an aperture element defining an optical aperture positioned in the path of the light beam from the light source; a photodetector positioned to receive the light beam within a sensing region after passing through the optical aperture and the at least one microfluidic sensing channel, the photodetector configured to provide the signal data indicative of an amount of light within the frequency band remaining after passing through the at least one microfluidic sensing channel; 28. The system of claim 26 or 27, comprising:

30. 30. The system of claim 29, wherein the aperture element comprises a plurality of optical apertures including the optical aperture positioned in the path of the light beam from the light source, the plurality of optical apertures comprising different sets of optical apertures aligned with each microfluidic sensing channel, each set of optical apertures defining a unique spacing pattern along a corresponding microfluidic sensing channel, the optical detector positioned to receive the light beam at the sensing region after passing through the plurality of optical apertures and the plurality of microfluidic sensing channels, and the controller configured to determine a number of particles associated with each size range based on the unique spacing patterns.

31. The system of any one of claims 27 to 30, wherein the particles comprise a second fluid different from the first fluid.

32. 32. The system of claim 31, wherein the controller is further configured to determine an amount of the second fluid in droplet form per unit volume of the first fluid based on the signal data.

33. 33. The system of claim 32, wherein the amount excludes the second fluid dissolved in the first fluid.

34. 34. The system of claim 31, wherein the controller is configured to determine a droplet velocity or a droplet size of one or more droplets of the second fluid dispersed in the stream of the first fluid based on the signal data.

35. The control device The magnitude of a pulse included in the signal data; a pulse width included in the signal data; and a first threshold signal level for detecting a minimum size droplet within the sensing area; a second threshold signal level for detecting a droplet filling the sensing area; Threshold signal level crossing rate and 35. The system of claim 34, configured to determine the droplet velocity or the droplet size based on at least one of:

36. The control device determining an amount of a second fluid in droplet form per unit volume of the first fluid based on the droplet velocity and droplet size; responsive to the signal not exceeding the second threshold signal level, determining the droplet size based on the magnitude of pulses included in the signal data; determining the droplet size based on the width of a pulse included in the signal data in response to the signal exceeding the second threshold signal level; and determining the droplet size based on the droplet rate; 36. The system of claim 35, further configured to perform at least one of:

37. The system of any one of claims 31 to 36, wherein the first fluid comprises a hydrocarbon fluid and the second fluid comprises water.

38. a plurality of microfluidic sensing channels each configured to receive a flow of a first fluid and particles dispersed in the first fluid, the particles having a different composition than the first fluid; a light source configured to direct a beam of light within a frequency band along a path through the plurality of microfluidic sensing channels, the frequency band selected such that absorbance by the particles differs from absorbance by the first fluid; an aperture element defining a plurality of optical apertures with a different set of optical apertures aligned with each microfluidic sensing channel, each set of optical apertures defining a unique spacing pattern along a corresponding microfluidic sensing channel; a photodetector positioned to receive the light beam at a sensing region after passing through the plurality of optical apertures of the aperture element and the plurality of microfluidic sensing channels, the photodetector configured to provide a signal representative of the amount of light within the frequency band remaining after passing through the plurality of microfluidic sensing channels; operatively coupled to the photodetector; determining signal data based on the signal from the photodetector; determining whether a particle has passed through the sensing region based on the signal data; determining the unique spacing pattern associated with the particles passed through the sensing region based on the signal data; A control device configured as follows: A system comprising:

39. 40. The system of claim 38, wherein each microfluidic sensing channel is configured to accept particles within a different size range, and the controller is further configured to determine a number of particles associated with each size range.

40. The method further comprises a hydrodynamic separation element positioned upstream of the plurality of microfluidic sensing channels, the hydrodynamic separation element comprising a plurality of hydrodynamic separators in serial fluid communication, including at least a first hydrodynamic separator and a second hydrodynamic separator, each defining a curved microfluidic separation channel for separating particles of different size ranges, each microfluidic separation channel comprising: an inlet configured to receive the first fluid and particles dispersed in the first fluid; an outlet having a first flow branch and a second flow branch; Define the at a particular flow rate, each microfluidic separation channel is configured to direct any particles above a corresponding threshold size to the second flow branch and any remaining particles to both the first flow branch and the second flow branch, and the first flow branch of the first hydrodynamic separator is in fluid communication with the inlet of the second hydrodynamic separator; 40. A system according to claim 38 or 39.

41. 41. The system of claim 40, wherein the controller is further configured to determine a number of particles associated with each size range based on a volume fraction associated with each flow branch based on the signal data.

42. 42. The system of claim 40 or 41, wherein the controller is operably coupled to a fluid pump in fluid communication with the hydrodynamic separation element, the controller being configured to control the fluid pump to pass the first fluid through the hydrodynamic separation element at the particular flow rate.

43. 43. The system of any one of claims 40-42, wherein at least one microfluidic sensing channel comprises an outlet comprising a first outlet branch and a second outlet branch, and further comprises at least one flow routing element positioned along the outlet of the at least one microfluidic sensing channel, wherein the controller is operatively coupled to the at least one flow routing element and is further configured to control the at least one flow routing element to direct fluid flow towards the second outlet branch in response to detection of a particle in a corresponding microfluidic sensing channel.

44. The system of any one of claims 38 to 43, wherein the particles comprise a second fluid different from the first fluid.

45. 45. The system of claim 44, wherein the controller is further configured to determine an amount of the second fluid in droplet form per unit volume of the first fluid based on the signal data.

46. 46. ​​The system of claim 45, wherein the amount excludes the second fluid dissolved in the first fluid.

47. 47. The system of any one of claims 44 to 46, wherein the controller is configured to determine a droplet velocity or a droplet size of one or more droplets of the second fluid dispersed in the stream of the first fluid based on the signal data.

48. The control device The magnitude of a pulse included in the signal data; a pulse width included in the signal data; and a first threshold signal level for detecting a minimum size droplet within the sensing area; a second threshold signal level for detecting a droplet filling the sensing area; Threshold signal level crossing rate and 48. The system of claim 47, configured to determine the droplet velocity or the droplet size based on at least one of:

49. The control device determining an amount of a second fluid in droplet form per unit volume of the first fluid based on the droplet velocity and droplet size; responsive to the signal not exceeding the second threshold signal level, determining the droplet size based on the magnitude of pulses included in the signal data; determining the droplet size based on the width of a pulse included in the signal data in response to the signal exceeding the second threshold signal level; and determining the droplet size based on the droplet rate; 49. The system of claim 48, further configured to perform at least one of:

50. 50. The system of any one of claims 44 to 49, wherein the first fluid comprises a hydrocarbon fluid and the second fluid comprises water.

51. a fuel line configured to deliver fuel to the fuel injector system; a hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel for separating particles in the fuel, each microfluidic channel comprising: an inlet in fluid communication with the fuel line for receiving fuel; a hydrodynamic separation element defining a first flow branch in fluid communication with the fuel line for supplying fuel to the fuel injector system, and an outlet having a second flow branch for receiving particles within a specified size range; A system comprising:

52. 52. The system of claim 51, wherein the particles comprise water droplets dispersed in the fuel.

53. 53. The system of claim 51 or 52, further comprising a fuel tank in fluid communication with each inlet and in fluid communication with each second flow branch.

54. 54. The system of any one of claims 51 to 53, further comprising a fuel filter positioned along the fuel line and configured to filter particles from gasoline or diesel fuel.

55. 55. The system of any one of claims 51 to 54, further comprising a fuel pump in fluid communication with the fuel line, the fuel pump configured to provide a flow of fuel along the fuel line to the fuel injector system, the fuel injector system comprising a high pressure common rail.

56. a fuel line configured to deliver fuel from the bulk fuel storage tank to the vehicle fuel tank; a hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel for separating particles in the fuel, each microfluidic channel comprising: an inlet in fluid communication with the fuel line for receiving fuel; a hydrodynamic separation element defining a first flow branch in fluid communication with the fuel line for supplying fuel to the vehicle fuel tank, and an outlet having a second flow branch for receiving particles within a specified size range; A system comprising:

57. 57. The system of claim 56, further comprising a bulk fuel storage tank in fluid communication with the inlet and optionally in fluid communication with the second flow branch for storing fuel.

58. 58. The system of claim 56 or 57, further comprising a secondary storage tank in fluid communication with the second flow branch for storing fuel.

59. 59. The system of any one of claims 56 to 58, further comprising a fuel filter positioned along the fuel line and configured to filter particles from gasoline or diesel fuel.

60. 60. The system of any one of claims 56 to 59, further comprising a fuel pump in fluid communication with the fuel line, the fuel pump configured to provide a flow of fuel along the fuel line to the vehicle fuel tank.

61. a hydraulic fluid line configured to deliver hydraulic fluid from the hydraulic pump to the hydraulic component; 1. A hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel for separating particles in the hydraulic fluid, wherein each microfluidic channel comprises: an inlet in fluid communication with the hydraulic fluid line for receiving hydraulic fluid from the hydraulic pump; a hydrodynamic separation element in fluid communication with the hydraulic fluid line and defining an outlet with a first flow branch for providing hydraulic fluid to the hydraulic component and a second flow branch for accepting particles within a specified size range; A system comprising:

62. 62. The system of claim 61, further comprising a hydraulic fluid filter positioned along a hydraulic fluid return line in fluid communication between the second flow branch and a hydraulic fluid reservoir for filtering particles from the hydraulic fluid, the hydraulic fluid reservoir being in fluid communication with an inlet of the hydraulic pump.

63. a hydraulic fluid return line configured to deliver hydraulic fluid from the hydraulic component to the hydraulic pump; 1. A hydrodynamic separation element comprising one or more hydrodynamic separators each defining a curved microfluidic channel for separating particles in the hydraulic fluid, wherein each microfluidic channel comprises: an inlet in fluid communication with the hydraulic fluid return line for receiving hydraulic fluid from the hydraulic pump; a hydrodynamic separation element in fluid communication with the hydraulic fluid return line and defining an outlet having a first flow branch for providing hydraulic fluid to the hydraulic pump and a second flow branch for accepting particles within a specified size range; A system comprising:

64. 64. The system of claim 63, wherein the particles comprise gas bubbles.

65. 65. The system of claim 64, further comprising a nucleation filter in fluid communication between the hydraulic component and the inlet for nucleating gas bubbles in the hydraulic fluid.

66. a main reservoir in fluid communication between the first flow branch and the hydraulic pump; a settling reservoir in fluid communication between the second flow branch and the main reservoir; 66. The system of claim 65, further comprising:

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