Methods and systems for monitoring characteristics in a fluid flow path having a filter for filtering fluid in the path
First Claim
1. A method of monitoring characteristics in a fluid flow path having a filter that is actively filtering fluid in the path, the method comprising the steps of:
- measuring Δ
P (pressure drop) in the fluid as it flows through the active filter;
normalizing the measured Δ
P to a state having predetermined reference conditions;
comparing the measured Δ
P at the normalized state to a Δ
P of a hypothetical reference filter for which there exists a known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions as a function of at least one of time, contaminant load and volume of fluid filtered;
wherein the contaminant removal from fluid is defined by the time-weighted ratio of the number concentration of particles larger than a certain size upstream of the hypothetical reference filter to the number concentration of particles larger than the same size downstream of the hypothetical reference filter under a standardized laboratory filter test; and
estimating contaminant removal from fluid filtered by the active filter as a function of at least one of time and contaminant load and volume of fluid filtered for the active filter wherein contaminant removal from fluid filtered by the active filter is estimated based on the known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions for the hypothetical reference filter.
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Accused Products
Abstract
Methods and systems are provided for measuring pressure drop through a filter in the flow path and then using the measured pressure drop, possibly at a normalized state and in conjunction with time and/or other data from the system, to estimate characteristics of the fluid, the filter, and/or a working component supplied with the filtered fluid. Such characteristics could include an operating condition of the filter, the remaining useful life of the filter, the relative contaminant concentration in the fluid, and/or the remaining useful life of a working component supplied with the filtered fluid.
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Citations
22 Claims
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1. A method of monitoring characteristics in a fluid flow path having a filter that is actively filtering fluid in the path, the method comprising the steps of:
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measuring Δ
P (pressure drop) in the fluid as it flows through the active filter;normalizing the measured Δ
P to a state having predetermined reference conditions;comparing the measured Δ
P at the normalized state to a Δ
P of a hypothetical reference filter for which there exists a known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions as a function of at least one of time, contaminant load and volume of fluid filtered;wherein the contaminant removal from fluid is defined by the time-weighted ratio of the number concentration of particles larger than a certain size upstream of the hypothetical reference filter to the number concentration of particles larger than the same size downstream of the hypothetical reference filter under a standardized laboratory filter test; and estimating contaminant removal from fluid filtered by the active filter as a function of at least one of time and contaminant load and volume of fluid filtered for the active filter wherein contaminant removal from fluid filtered by the active filter is estimated based on the known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions for the hypothetical reference filter. - View Dependent Claims (2, 3, 4, 5)
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6. A method of monitoring characteristics in a fluid flow path having a filter that is actively filtering fluid in the path, the method comprising the steps of:
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measuring Δ
P (pressure drop) in the fluid as it flows through the active filter;normalizing the measured Δ
P to a state having predetermined reference conditions;comparing the measured Δ
P at the normalized state to a Δ
P of a hypothetical reference filter for which there exists a known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions as a function of at least one of time, contaminant load and volume of fluid filtered;wherein the contaminant removal from fluid is defined by the time-weighted ratio of the number concentration of particles larger than a certain size upstream of the hypothetical reference filter to the number concentration of particles larger than the same size downstream of the hypothetical reference filter under a standardized laboratory filter test; and determining an operational condition of the active filter wherein the operational condition is determined based on the known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions for the hypothetical reference filter. - View Dependent Claims (7, 8, 9, 10, 11, 12)
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13. A fluid filtration system comprising:
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a fluid flow path having at least one filter actively filtering fluid that flows along the flow path; a sensor measuring Δ
P (pressure drop) in the fluid as it flows through the active filter; anda controller programmed to (1) normalize the measured Δ
P to a state having predetermined reference conditions, (2) compare the measured Δ
P at the normalized state to a Δ
P of a hypothetical reference filter for which there exists a known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions as a function of at least one of time, contaminant load and volume of fluid filtered, (3) analyze the contaminant removal from the fluid, and (4) define contaminant removal from fluid by the time-weighted ratio of the number concentration of particles larger than a certain size upstream of the hypothetical reference filter to the number concentration of particles larger than the same size downstream of the hypothetical reference filter under a standardized laboratory filter test; andwherein the controller is programmed to estimate contaminant removal from fluid filtered by the active filter as a function of at least one of time, contaminant load and volume of fluid filtered for the active filter, and the controller estimates contaminant removal from fluid filtered by the active filter based on the known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions for the hypothetical reference filter. - View Dependent Claims (14, 15, 16)
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17. A fluid filtration system comprising:
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a fluid flow path having at least one filter actively filtering fluid that flows along the flow path; a sensor measuring Δ
P (pressure drop) in the fluid as it flows through the active filter; anda controller programmed to (1) normalize the measured Δ
P to a state having predetermined reference conditions, (2) compare the measured Δ
P at the normalized state to a Δ
P of a hypothetical reference filter for which there exists a known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions as a function of at least one of time, contaminant load and volume of fluid filtered, (3) analyze the contaminant removal from the fluid, and (4) define contaminant removal from fluid by the time-weighted ratio of the number concentration of particles larger than a certain size upstream of the hypothetical reference filter to the number concentration of particles larger than the same size downstream of the hypothetical reference filter under a standardized laboratory filter test; andwherein the controller is programmed to determine an operational condition of the active filter, and the programmed controller determines the operational condition based on the known correlation between Δ
P and contaminant removal from fluid under the predetermined reference conditions for the hypothetical reference filter. - View Dependent Claims (18, 19, 20, 21, 22)
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Specification