JP5002608B2 - Hard particle concentration detection method - Google Patents

Description

  The present invention relates to a method for detecting the concentration of hard particles contained in a liquid.

  Generally, liquids such as C heavy oil, which is the main fuel of marine diesel engines, are mixed with hard particles such as alumina, silica, and carbon as a residue of fluid catalytic cracking (FCC) during petroleum refining.

  If these hard particles excessively flow into the drive engines such as engine piston rings and cylinder liners, the ship management company may cause adverse effects such as deterioration of the sliding condition, seizure, and mechanical wear. Then, for each bunkering, fuel is sampled and chemically analyzed, and the hard particles in the fuel are quantitatively grasped. When fuel containing hard particles exceeding the specified value is bunkered to the ship, We were informed that hard particles were above the specified value and cautioned.

  Conventionally, when detecting hard particles, the fuel sampled from the liquid is filtered through a filter or the like, and the hard particles are detected by observation of the residue with a microscope or quantitative analysis.

  For example, Patent Document 1 shows a general technical level of a hard particle concentration detection method.

JP 11-153541 A

  However, since the conventional method for detecting the concentration of hard particles requires a certain number of days to report the result to the ship, if it is necessary to use fuel before the analysis result becomes clear, it should be sent to the driving engine. There was a problem that the adverse effects of could not be prevented. Also, when contaminants containing hard particles precipitate during storage and the concentration of hard particles increases, or when problems such as centrifugal cleaners and filters occur in the fuel processing system from the fuel tank to the engine inlet There is a possibility that a large amount of hard particles may be suddenly supplied to the drive engine, and it has been required to quantitatively and quickly grasp the hard particles in the fuel.

  Furthermore, since hard particles such as alumina and silica do not have remarkable characteristics in conductivity and magnetism, it is difficult to detect electrically and magnetically, and hard particles are chemically stable substances. There was a problem that it was difficult to detect using a chemical reaction. Furthermore, since liquids such as C heavy oil are highly viscous and opaque and contain hard particles such as various sludges in addition to alumina / silica particles, there has been a problem that even optical detection as in Patent Document 1 cannot be sufficiently performed.

  In view of such circumstances, the present invention intends to provide a hard particle concentration detection method for quantitatively and quickly grasping hard particles in a liquid.

  In the method for detecting the concentration of hard particles according to the present invention, the magnetic member and the corresponding member are immersed in a liquid that may contain hard particles, and at least one of the magnetic member and the corresponding member is pressed against the other to move the hard member in the liquid. The magnetic member is worn by the particles to generate magnetic particles, the concentration of magnetic particles generated in the sample liquid is measured, and the correlation between the magnetic particle concentration measured in advance and the concentration of hard particles in the liquid is shown. From the calibration curve, the concentration of magnetic particles is converted into the concentration of hard particles in the liquid, and the concentration of hard particles contained in the liquid is detected.

  In the hard particle concentration detection method of the present invention, it is preferable that hard particles in the liquid are sandwiched between the magnetic member and the corresponding member, and at least one of the magnetic member and the corresponding member is pressed against the other to move.

  According to the hard particle concentration detection method of the present invention, the magnetic member is worn by the presence of hard particles in the liquid to generate magnetic particles, the concentration of the magnetic particles generated in the liquid is measured, and the magnetic curve is measured from the calibration curve. Since the concentration of particles is converted into the concentration of hard particles in the liquid and the concentration of hard particles contained in the liquid is detected, the hard particles in the liquid can be grasped quantitatively and quickly. Further, when the liquid is oil, it is possible to prevent a situation in which uninspected fuel is used and a situation in which a large amount of hard particles are suddenly supplied to the driving engine, thereby suppressing adverse effects on the driving engine. Furthermore, since the concentration of hard particles is indirectly detected using magnetic particles generated by wear of the magnetic member, the operation and processing for directly detecting the hard particles by physically and chemically treating the liquid itself are unnecessary, The excellent effect that the hard particle | grains in a liquid can be grasped | ascertained quantitatively and rapidly suitably can be show | played.

It is a flow which shows the process sequence of the density | concentration detection method of the hard particle | grains of this invention. It is a density | concentration detection method of the hard particle | grains of this invention, and is a whole conceptual diagram which shows a magnetic particle generation means. It is a conceptual diagram which expands and shows the part of the magnetic member and corresponding member in the magnetic particle generation means of FIG. It is the IV-IV arrow line view of FIG. (A) is a conceptual diagram showing portions of magnetic members and corresponding members in other magnetic particle generating means, (b) is a conceptual diagram showing portions of magnetic members and corresponding members in another magnetic particle generating means, (C) is a conceptual diagram which shows the part of the magnetic member in another magnetic particle generation means, and a corresponding member. It is a density | concentration detection method of the hard particle | grains of this invention, Comprising: It is a whole conceptual diagram which shows an example of a magnetic particle measurement means. It is a density | concentration detection method of the hard particle | grains of this invention, Comprising: It is a whole conceptual diagram which shows the other example of a magnetic particle measurement means. It is a block diagram which shows the structure of the signal processing part in a magnetic particle measurement means. It is a conceptual diagram which shows the process from an output signal to the output value for a comparison in the state without the influence of a magnetic particle. It is a conceptual diagram which shows the process from an output signal to the output value for the density | concentration of a magnetic particle in the state which has the influence of a magnetic particle. It is a graph which shows the relationship between the drive time (polishing time) of a magnetic particle generation means, and the density | concentration of a magnetic particle (magnetic powder Fe). It is a calibration curve showing the relationship between the concentration of hard particles and the concentration of magnetic particles (magnetic powder).

  Embodiments of the present invention will be described below with reference to FIGS. FIGS. 1-12 is an example which implements the density | concentration detection method of a hard particle.

  In the method for detecting the concentration of hard particles according to the embodiment, magnetic particle generating means (magnetic powder generating means) 1 for generating magnetic particles (magnetic powder) in the liquid and the concentration of the magnetic particles in the liquid are measured. A magnetic particle measuring means 2 (see FIGS. 6 to 8) and a control unit 3 (see FIGS. 6 and 7) for processing the concentration of magnetic particles are provided. In this embodiment, the liquid is oil. explain.

  The magnetic particle generating means 1 includes a drive unit 5 such as a motor having a rotating shaft 4 below, a holder unit 6 disposed on the driving unit 5 so as to surround the rotating shaft 4, and a holder unit connected to the rotating shaft 4. A rod portion 7 extending from the lower portion 6 to the outside, a sleeve 8 supported on the holder portion 6 and provided on the outer periphery of the rod portion 7, an elastic means 9 such as a spring forcing the sleeve 8 downward, A wear plate corresponding member 11 and a plate-like magnetic member 12 are provided below the sleeve 8 by a fixing means 10 such as a nut.

  The drive part 5 and the holder part 6 are fixed to a pedestal (not shown) so that the rod part 7, the sleeve 8 and the like are exposed downward. Further, the holder portion 6 is provided with a downward projecting portion 14 into which the container portion 13 can be inserted so that the container portion 13 such as a test tube containing oil S such as fuel can be attached. Further, an O-ring 15 is arranged with a groove on the outer periphery of the downward projection 14.

  The rod portion 7 has a length that can be accommodated in the container portion 13 together with the sleeve 8, the elastic means 9, the corresponding member 11, and the magnetic member 12 when the container portion 13 is disposed on the holder portion 6. It is configured to rotate. Further, on both sides of the rod portion 7, both side surfaces 7 a (see FIG. 4) are formed such that both sides of the outer periphery of the rod portion 7 are notched into a plane.

  The sleeve 8 forms an upper receiving portion 16 that supports the lower portion of the elastic means 9 and also forms a lower receiving portion 17 that contacts the corresponding member 11. Further, the elastic means 9 is supported by the lower convex portion 14 of the holder portion 6 and biases the corresponding member 11 downward via the sleeve 8 so as to press the corresponding member 11 against the magnetic member 12. Here, the pressing of the corresponding member 11 and the magnetic member 12 is preferably adjusted by changing the elastic means 9 such as a spring.

  The corresponding member 11 includes a hole (not shown) through which the rod portion 7 is inserted, and is arranged without following the rotation of the rod portion 7. The magnetic member 12 is a hole 18 (see FIG. 4), and a straight side portion 18a on both sides that can contact both side surfaces 7a below the rod portion 7 is formed in the hole 18 so as to follow the rotation of the rod portion 7. The magnetic member 12 is made of a material such as an iron-based material having magnetism, and the corresponding member 11 is made of a material such as carbon steel that is harder and harder to wear than the magnetic member 12. Further, a groove 12 a facing the other member is formed in one of the corresponding member 11 and the magnetic member 12 (the magnetic member 12 in FIGS. 2 and 3), and between the corresponding member 11 and the magnetic member 12. When the magnetic member 12 rotates with the presence of hard particles, the magnetic member 12 is scraped off by the hard particles to cause abrasive wear. Here, the material of the magnetic member 12 is not limited to iron as long as magnetic particles (magnetic powder) having a predetermined particle diameter are formed by wear, and other materials may be used. The material of the corresponding member 11 may be another material as long as magnetic particles are generated from the magnetic member 12, or may be the same material as the magnetic member 12. Furthermore, the arrangement of the magnetic member 12 and the corresponding member 11 may be reversed.

  Here, the magnetic particle generating means 1 may be another example in which the configuration of the magnetic member 12 and the corresponding member 11 is changed. Specifically, as another example, as shown in FIG. 5A, a shaft portion 19 rotated by a driving means (not shown), a roller portion 20 positioned at the center of the shaft portion 19, and a fixing means (see FIG. 5). A plate portion 21 fixed to the roller portion 20 and an elastic means 22 such as a spring for biasing the shaft portion 19 so as to press the roller portion 20 against the plate portion 21. One of the portion 20 and the plate portion 21 is provided, and the corresponding member is the other of the roller portion 20 and the plate portion 21.

  As another example, as shown in FIG. 5B, a shaft portion 23 rotated by a driving means (not shown), a rotating plate 24 positioned at the tip of the shaft portion 23, and a fixing means (not shown). ) And an elastic means 26 such as a spring for pressing the rotating plate 24 against the plate portion 25, and the magnetic member is any of the rotating plate 24 and the plate portion 25. One of them is configured such that the corresponding member is either the rotating plate 24 or the plate portion 25.

  As another example, as shown in FIG. 5C, an eccentric pin 28 rotated by the driving means 27, a connecting member 29 for converting the movement of the eccentric pin 28 into a reciprocating movement, and a connecting member 29 are connected. A reciprocating plate 30, a plate portion 31 fixed to a fixing means (not shown) and contacting the lower surface of the reciprocating plate 30, and elastic means 32 such as a spring for pressing the reciprocating plate 30 against the plate portion 31. The magnetic member is one of the reciprocating plate 30 and the plate portion 31, and the corresponding member is one of the other of the reciprocating plate 30 and the plate portion 31.

  On the other hand, the configuration of the magnetic particle measuring means 2 is not particularly limited as long as it can measure the concentration of magnetic particles in ppm, but an example will be described. As shown in FIGS. 6 to 10, the magnetic particle measuring means 2 of the example includes a fluid lead-in / out means 33 and a detection means 34 in the flow path L of the oil S that may contain magnetic particles. 35 is connected, and the signal processing unit 35 is connected to a concentration measuring unit 36 for converting the signal of the signal processing unit 35 into the concentration of magnetic particles.

  The fluid lead-in / out means 33 includes a cylindrical detection portion main body 38 that forms an opening 37 in the flow path L, a piston 39 that slides inside the detection portion main body 38 to lead in and out the oil S, and a forward and backward movement of the piston 39. The rotating part 40 (refer FIG. 8) of the drive means to move is provided, and the coil 41 of the detection means 34 arrange | positioned in the outer peripheral part of the detection part main body 38 is provided. Here, the flow path L may be a pipe, a tube, or the like, or any type as long as the oil S flows.

  The coil 41 of the detection means 34 includes two excitation coils 41a and 41a wound in opposite directions and connected in series, and a detection coil disposed in proximity between the two excitation coils 41a and 41a. (Output coil) 41b. When an AC voltage is applied to the excitation coil 41a, an output signal of an AC voltage (excitation voltage) is generated in the detection coil 41b. Further, the two exciting coils 41a and 41a and the detecting coil 41b have the same mutual inductance by adjusting the number of turns of the coil 41 and the distance between the coils 41 so that the mutual inductance is substantially equal. It is adjusted so that. Further, the number of exciting coils 41a and detecting coils 41b is not particularly limited.

  Here, as shown in FIG. 7, the coil 41 of the detection means 34 includes one excitation coil 41c and a detection coil (output coil) 41d arranged in the vicinity of one excitation coil 41c. Similarly, in this case, when an AC voltage is applied to the excitation coil 41c, an output signal of an AC voltage (excitation voltage) is generated in the detection coil 41d, and magnetic particles are not detected. Sometimes, the output signal of the alternating voltage (excitation voltage) of the detection coil 41d is adjusted to be small.

  The signal processing unit 35 is connected to the detection coil 41b and amplifies a weak waveform signal so as to obtain a magnetic particle detection signal or a correction detection signal from the output signal of the detection coil 41b as shown in FIG. A circuit 42; a band-pass filter 43 connected to the amplifier circuit 42 for removing the noise of the waveform signal within a predetermined range; a sine wave oscillation circuit 44 connected to the excitation coil 41a to obtain an excitation sine wave; A phase circuit 45 that is connected to the wave oscillation circuit 44 and shifts the phase of the sine wave, and an edge trigger circuit 46 that is connected to the phase circuit 45 and converts the sine wave into a rectangular wave are provided.

  Here, it is preferable that the phase circuit 45 shifts the phase by 10 ° to 170 °, preferably 45 ° to 135 °, and more preferably around 90 ° in the state when magnetic particles are not detected during setting or adjustment. . The phase circuit 45 may be positioned between the bandpass filter 43 and the signal processing device 47, and may shift the detection signal of magnetic particles and the detection signal for correction instead of the reference signal.

  The signal processing unit 35 includes a signal processing device 47 connected to the band-pass filter 43 and the edge trigger circuit 46, a low-pass filter 48 connected to the signal processing device 47 to convert an output signal into a DC voltage signal, An amplifier 49 that is connected to the low-pass filter 48 and amplifies the DC voltage signal, an AC signal transmission circuit 50 that is connected to the amplifier 49 and transmits only the fluctuation amount of the DC voltage signal due to the introduction and detection of the detection fluid, and an AC signal transmission circuit 50 and an amplifier 51 connected to 50. Here, the signal processing device 47 is preferably a lock-in amplifier, but may be any device as long as it can measure a change in phase difference.

  Further, the concentration measuring unit 36 shown in FIGS. 6 and 7 is connected to the amplifier 51 of the signal processing unit 35 so as to convert the signal into the concentration of magnetic particles.

  On the other hand, the control unit 3 for processing the concentration of the magnetic particles is connected to the concentration measuring unit 36 of the magnetic particle measuring unit 2, and the concentration of the magnetic particles measured by the magnetic particle measuring unit 2 is calculated in advance. In contrast to the line (see FIG. 12), the concentration of the hard particles in the oil S is converted into the concentration of the hard particles, and the concentration of the hard particles contained in the oil S is detected and displayed. Here, the processing of the control unit 3 may be performed manually, and is not particularly limited.

  The operation of the embodiment of the present invention will be described below.

  When inspecting oil S such as fuel that may contain hard particles, first a small amount of oil S (sample) is sampled from the engine inlet of the fuel system as shown in FIG. 1 (step S1). Here, the oil S such as fuel to be inspected is not limited to heavy oil such as C heavy oil, and may be other oil S such as gasoline, kerosene, light oil and the like as long as it can contain hard particles. The use of the oil S is not limited to supply to a drive engine such as a ship, but may be supplied to various drive engines and equipment such as a turbine plant. Further, water or an aqueous solution may be used instead of oil, and it is not particularly limited as long as it can contain hard particles. Furthermore, when inspecting water or aqueous solution, it may be used for detection of particulate impurities mixed in circulating water such as a water circulation type compressor, it may be used for water quality inspection of working water of hydraulic equipment, or water treatment You may use for the quality control of the treated water in an installation. Further, the hard particles are non-conductive and non-magnetic particles contained in a liquid such as oil S or water and can wear the magnetic member 12, and are not limited to alumina, silica, carbon, or the like. Absent.

  Next, a small amount of sampled oil S (sample) is set in the magnetic particle measuring means 2, and the concentration (A) of the magnetic particles contained in the oil S in advance is measured (step S2). Here, the processing of the magnetic particle measuring means 2 will be described in the following processing, but the concentration (A) of the magnetic particles may be measured using other means. In addition, when setting the oil S in the magnetic particle measuring means 2, the sampling from the oil S to the setting to the magnetic particle measuring means 2 is continuously performed via an oil supply means such as an oil supply channel without manual intervention. You may do it.

  Subsequently, after measuring the concentration (A) of the magnetic particles contained in the oil S in advance, the oil S (sample) is put into the container part 13 and the container part 13 is set in the magnetic particle generating means 1 for preparation (step). S3). In the concrete body, the container part 13 containing the oil S is fixed to the downward convex part 14 of the holder part 6 so that the magnetic member 12 and the corresponding member 11 together with the rod part 7 and the like are immersed in the oil S. In the case of another configuration of the magnetic particle generating means 1 shown in FIG. 5, the magnetic member and the corresponding member are similarly immersed in the oil S. Here, the transition from the magnetic particle measuring means 2 to the magnetic particle generating means 1 may be performed manually or automatically via transfer means such as a flow path or an on-off valve.

  Subsequently, the magnetic particle generating means 1 is driven for a certain time to generate magnetic particles such as iron powder in the oil S (step S4). Specifically, the drive unit 5 is driven to rotate the rod unit 7, the magnetic member 12 is rotated while pressing the corresponding member 11, and the hard member that has entered between the magnetic member 12 and the corresponding member 11 causes the magnetic member to rotate. 12 is worn to generate magnetic particles. In the case of another configuration of the magnetic particle generating means 1 shown in FIG. 5, the magnetic member 12 is similarly worn to generate magnetic particles such as iron powder. Here, since the viscosity of the oil S is kept constant, if the pressing surface pressure of the magnetic member 12 and the corresponding member 11 is appropriately maintained, only the hard particles having a certain size or more can be used as magnetic particles (iron powder). In the case of hard particles having a diameter smaller than that, the magnetic particles (iron powder) are not generated only by passing through the gap between the magnetic member 12 and the corresponding member 11.

  Then, after magnetic particles are generated in the oil S by the magnetic particle generating means 1, the magnetic particle generating means 1 sets the magnetic particles in the magnetic particle measuring means 2, and the process proceeds to the next processing. Here, the transition from the magnetic particle generating means 1 to the magnetic particle measuring means 2 may be performed manually or automatically via transfer means such as a flow path or an on-off valve.

  Next, the magnetic particle concentration means 2 measures the magnetic particle concentration (B) (step S5). When measuring the concentration (B) of the magnetic particles, by continuously reciprocating the piston 39 of the fluid lead-in / out means 33, a measurement process in a state where the oil S is introduced into the detection unit main body 38; The measurement process in a state in which the oil S is discharged from the detection unit main body 38 is alternately and continuously repeated, and the AC signal transmission circuit 50 and the like are used to calculate the magnetic substance concentration output value and the comparison output value. A difference signal is detected and a moving average process is performed, and an average value of the concentration of the magnetic particles is obtained via the concentration measuring unit 36.

  Here, the process of measuring the concentration of magnetic particles will be described in detail. When oil S is discharged from the detection unit main body 38, the detection coil 41b, the amplification circuit 42, and the bandpass filter 43 are extracted from the detection unit main body 38. (A in FIG. 9), and the excitation voltage is shifted by a predetermined angle by the excitation coil 41a, the sine wave oscillation circuit 44, the phase circuit 45 and the edge trigger circuit 46. A reference signal of a rectangular wave that produces a constant phase difference at the same frequency is prepared ((B) in FIG. 9, the phase is shifted by about 90 °). The signal processing device 47 combines the reference signal to remove noise, detects a phase difference between the correction detection signal and the reference signal, and converts it to a smooth DC voltage signal as a comparison output value by the low-pass filter 48. (D in FIG. 9) is input to the AC signal transmission circuit 50 through the amplifier 49. On the other hand, when the oil S is introduced into the detection unit main body 38, a detection signal of the magnetic material is acquired from the oil S through the detection coil 41b, the amplification circuit 42, and the band pass filter 43 (in FIG. A ′)) together with the exciting coil 41a, the sine wave oscillation circuit 44, the phase circuit 45 and the edge trigger circuit 46, a rectangular wave that shifts the phase by a predetermined angle and produces a constant phase difference at the same frequency as the excitation voltage. A reference signal is prepared (in FIG. 10, (B ′), the phase is shifted by about 90 °). The signal processing device 47 combines the reference signal to remove noise, detects the phase difference between the magnetic substance detection signal and the reference signal, and the low-pass filter 48 provides a smooth direct current as an output value for the magnetic substance concentration. It is converted into a voltage signal ((D ′) in FIG. 10) and input to the AC signal transmission circuit 50 via the amplifier 49. Then, the AC signal transmission circuit 50 obtains a difference ΔV from the output value for the concentration of the magnetic particles and the output value for comparison so as to correct the output value for the concentration of the magnetic particles, as shown in FIG. The unit 36 converts the difference into the concentration of the magnetic particles by the correlation (function processing) with the concentration obtained in advance.

  According to the results of experiments conducted by the present inventor, when the oil S containing magnetic particles (iron powder) in ppm is measured in the embodiment, the output (concentration) increases at the same time when the oil S is introduced. Furthermore, the output (concentration) decreased with the discharge of the oil S, and it was clear that the reaction to the magnetic particles was clear and rapid, and the concentration of the magnetic particles could be measured with high accuracy.

  After measuring the concentration of the magnetic particles by the magnetic particle measuring means 2, the concentration (A) of the magnetic particles previously contained in the oil S is calculated from the concentration (B) of the magnetic particles after being processed by the magnetic particle generating means 1. Subtraction is performed (concentration of magnetic particles (B) −concentration of magnetic particles (A)), and the concentration (c) of magnetic particles actually generated by the magnetic particle generating means 1 is calculated (step S6).

  Here, the relationship between the drive time (polishing time) of the magnetic particle generating means 1 and the concentration of the magnetic particles (magnetic powder Fe) was tested. As shown in FIG. The concentration of magnetic particles inside increased. Further, when the concentration of the hard particles previously contained in the oil S is changed (in the graph of FIG. 11, αppm and about 1 / 2αppm are not included), the concentration of the hard particles is proportional to the generation concentration of the magnetic particles. It turns out that there is a relationship. Thus, when the concentration of the hard particles and the concentration of the magnetic particles (magnetic powder) are plotted under the condition that the driving time (polishing time) of the magnetic particle generating means 1 is constant, as shown in FIG. A calibration curve showing the correlation between the concentration of the oil and the concentration of hard particles in the oil S is created. The calibration curve is applied in the following process.

  After calculating the concentration (c) of the actually generated magnetic particles, the concentration of the magnetic particles is converted into the concentration of hard particles in the oil S from the calibration curve (step S7, A to B in FIG. 12). Here, the conversion into the concentration of the hard particles may be processed by registering the calibration curve in the control unit 3 in advance or may be processed manually.

  And the density | concentration of a hard particle is displayed on display means, such as the control part 3 (step S8), and while detecting a hard particle in the oil S, the hard particle in the oil S is grasped | ascertained quantitatively and rapidly. As a result, when oil S such as fuel is supplied to a predetermined driving engine such as a ship, the concentration of hard particles such as alumina and silica is determined in the field, and adverse effects on the driving engine due to the hard particles are obviated. To avoid.

  Thus, according to the embodiment, the magnetic member 12 is worn from the presence of the hard particles in the oil S to generate magnetic particles, and the concentration of the magnetic particles generated in the oil S is measured. Since the concentration of magnetic particles is converted to the concentration of hard particles in oil S from the calibration curve, and the concentration of hard particles contained in oil S is detected, until the concentration of hard particles is detected as in the conventional measuring means. The hard particles in the oil S can be grasped quantitatively and quickly without requiring days, so that the situation in which uninspected fuel is used and a large amount of hard particles are suddenly supplied to the drive engine. Can be prevented, and adverse effects on the drive engine can be suppressed. In addition, since the concentration of hard particles is indirectly detected using magnetic particles such as iron powder generated by wear of the magnetic member 12, the hard particles are directly detected by physically and chemically treating the oil S itself. Therefore, it is possible to grasp the hard particles in the oil S quantitatively and quickly.

  In the embodiment, when hard particles in the oil S are sandwiched between the magnetic member 12 and the corresponding member 11 and at least one of the magnetic member 12 and the corresponding member 11 is pressed against the other and moved, Since the magnetic member 12 is appropriately worn by the presence of the hard particles to generate magnetic particles, the concentration of the hard particles contained in the oil S is easily detected, and the hard particles in the oil S are more suitably grasped. Can do.

  Further, when an entry passage such as a groove 12a is provided in at least one of the magnetic member 12 and the corresponding member 11 so that the sample oil can easily enter the gap, the generation and discharge of magnetic particles (iron powder) are promoted. Therefore, the concentration of the hard particles contained in the oil S can be easily detected and the hard particles in the oil S can be grasped more suitably.

  Furthermore, since it can be applied not only to oil but also to water or an aqueous solution, it is highly versatile, and the concentration of hard particles can be easily detected from water or an aqueous solution.

  The method for detecting the concentration of hard particles according to the present invention is not limited to the above-described illustrated examples, and it is needless to say that various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Magnetic particle generating means 2 Magnetic particle measuring means 11 Corresponding member 12 Magnetic member S Oil (liquid)

Claims (2)

  The magnetic member and the corresponding member are immersed in a liquid that may contain hard particles, and at least one of the magnetic member and the corresponding member is pressed against the other to move, and the magnetic member is abraded by the hard particles in the liquid to cause the magnetic particles to move. The concentration of magnetic particles generated in the liquid of the sample is measured, and the concentration of magnetic particles in the liquid is determined from a calibration curve indicating the correlation between the concentration of magnetic particles measured in advance and the concentration of hard particles in the liquid. A method for detecting the concentration of hard particles, wherein the concentration of hard particles is detected by converting to the concentration of hard particles.   2. The hard particle concentration detection method according to claim 1, wherein hard particles in the liquid are sandwiched between the magnetic member and the corresponding member, and at least one of the magnetic member and the corresponding member is pressed against the other to move. .

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