MAGNETIC INDUCTION PARTICLE DETECTION DEVICE AND CONCENTRATION DETECTION METHOD

Abstract

The invention provides a magnetic induction particle detection device and a concentration detection method, wherein the detection device comprises a signal detection system, a detection pipeline, excitation coil and a positive even number of induction coils, and the excitation coil are connected with the signal detection system and wound around the detection pipeline; the induction coils are connected with the signal detection system and wound around the excitation coil sequentially and reversely with respect to each other. By means of the device, preparation and installation can be facilitated, and detection precision can be improved. The method comprises the steps of: S1: acquiring an output signal of the signal detection system and obtaining a voltage amplitude change; and S2: according to the obtained voltage amplitude change, detecting the metal particle concentration. By means of the method, the precision of calculation can be improved.

Claims

1. A magnetic induction particle detection device, comprising: a signal detection system; a detection pipeline; an excitation coil; and a positive even number of induction coils, wherein the excitation coil is connected with the signal detection system and wound around the detection pipeline, and the induction coils are connected with the signal detection system and wound around the excitation coil sequentially and reversely with respect to each other.

2. The magnetic induction particle detection device according to claim 1, wherein the excitation coils are two or more, and each of the excitation coils are wound around the detection pipeline in same direction.

3. The magnetic induction particle detection device according to claim 1, wherein the excitation coil and/or the induction coils are wound in at least one layer.

4. The magnetic induction particle detection device claim 1, wherein the detection pipeline is made of a non-magnetic conductive material.

5. The magnetic induction particle detection device according to claim 1, wherein a spacer ring sleeve is further arranged between the excitation coil and the induction coils.

6. The magnetic induction particle detection device according to claim 1, wherein a shielding ring is arranged outside the induction coils.

7. A concentration detection method applying the magnetic induction particle detection device according to claim 1, wherein the method comprises steps of: S1: acquiring an output signal of the signal detection system to obtain a voltage amplitude change; S2: detecting a metal particle concentration according to the obtained voltage amplitude change.

8. The concentration detection method according to claim 7, wherein said obtaining the flow velocity v of the metal particles comprises steps of: respectively recording time when voltage amplitude of the metal particles passing through a group of the induction coils measured by the signal detection system is at highest point and at zero point during positive half cycle, and calculating time difference value T.sub.1 and length L.sub.1 of the corresponding induction coils; respectively recording time when voltage amplitude, measured by the signal detection system, is at zero point and at highest point during negative half cycle, and calculating time difference value T.sub.2 and length L.sub.2 of the corresponding induction coils; and obtaining the flow velocity according to formula: $v = \frac{\frac{k_{1} L_{1}}{.Math. .Math. T_{1}} + \frac{k_{2} L_{2}}{.Math. .Math. T_{2}}}{2}$

9. The concentration detection method according to claim 7, wherein if there are multiple groups of the induction coils, the flow velocity v of the metal particles passing through the induction coils is an average value of flow velocities of the particles passing through each said group of induction coils.

10. The concentration detection method according to claim 7, wherein a frequency at which the output signal of the signal detection system is acquired in S1 is once per millisecond.

11. The magnetic induction particle detection device according to claim 1, wherein the number of the induction coils is two or four or six.

12. The magnetic induction particle detection device according to claim 4, wherein the detection pipeline is made of stainless steel.

13. The magnetic induction particle detection device according to claim 5, wherein the spacer ring sleeve is made of a non-magnetic conductive material.

14. The concentration detection method according to claim 7, wherein said detecting said metal particle concentration comprises the steps of: obtaining flow velocity v of metal particles passing through the induction coils; obtaining mass m of the metal particles; and calculating concentration of the particles c on the basis of the flow velocity v of the metal particles, the mass m of the metal particles, elapsed time t and cross-sectional area S of the detection pipeline by using following formula: $c = \frac{m}{v t S}$

Description

DRAWINGS

[0067] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0068] FIG. 1 is a schematic cross-sectional view of a first preferred embodiment of the magnetic induction particle detection device of the present invention;

[0069] FIG. 2 is a schematic cross-sectional view of a second preferred embodiment of the magnetic induction particle detection device of the present invention;

[0070] FIG. 3 is a partially enlarged schematic view of area A in FIG. 2;

[0071] FIG. 4 is a schematic diagram showing the principle of electromagnetic induction test performed by the magnetic induction particle detection device of the present invention;

[0072] FIG. 5 is a graph of voltage output change corresponding to the schematic diagram of mechanism of FIG. 4.

[0073] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

[0074] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0075] In order to further illustrate the technical means of the present invention for achieving the intended purposes thereof as well as effects, the following detailed description is made, taken in conjunction with the accompanying drawings and preferred embodiments, to illustrate specific embodiments, structures, features and efficacy thereof according to the present invention.

Embodiment 1 (Magnetic Induction Particle Detection Device)

[0076] FIG. 1 is a schematic cross-sectional view of a first preferred embodiment of the magnetic induction particle detection device of the present invention; the detection device comprises a signal detection system 1, a detection pipeline 2, an excitation coil 3 and two induction coils (a first induction coil 4 and a second induction coil 5 respectively), wherein the excitation coil is connected with the signal detection system and wound around the detection pipeline; the induction coils are connected with the signal detection system and wound around the excitation coil sequentially and reversely with respect to each other.

[0077] The above is one of the preferred embodiments of the present technical solution. This embodiment has the following beneficial effects:

[0078] (1) According to the device, the induction coil is wound outside the excitation coil, so that the installation is convenient, the whole length of the sensor is greatly shortened, and prepare and use of the device are facilitated;

[0079] (2) The induction coil of the device is wound around the detection pipeline, so that measurement of particles can be detected, without contacting the sensor directly with liquid in the pipeline, so that the test is more convenient;

[0080] (3) The induction coils are sequentially wound around the excitation coil, so that the magnetic field disturbance generated when particles pass through the induction coils can be quickly detected, so as to achieve the detection of metal particles;

[0081] (4) The induction coils are wound reversely with each other on the excitation coil; due to the proximity of the induction coils, the environment of the induction coils can be considered to be consistent, temperature drift and electromagnetic interference can be restrained in a complex and severe environment, and thus signal stability is enhanced and system performance is further improved.

[0082] In this embodiment, there is one excitation coil for generating a magnetic field. In other embodiments, the number of the excitation coil may be two or more, but co-directional winding is required to prevent mutual interference of the magnetic fields and influence on the measurement effect.

[0083] In this embodiment, there are two induction coils. This arrangement can effectively improve the detection accuracy and ensure a better detection effect. Or in other embodiments, the number of the induction coils is a positive even number, such as four, six or more, on the one hand, the same detection effect can be achieved, and on the other hand, the detection reliability can be improved by averaging multiple measurements.

[0084] In this embodiment, the material of the detection pipeline is made of a non-magnetic conductive material; further preferably, the detection pipeline is made of stainless steel. The detection pipeline is made of a non-magnetic conductive material so as to measure the magnetic field disturbance generated by metal particles on the excitation coil more accurately. In the testing process, it's necessary to try to ensure that the magnetic field generated by the excitation coil pass through the pipeline to improve the magnetic field strength therein. More preferably, a non-magnetic conductive stainless steel material is used, which meets the requirement but does not exclude other materials.

Embodiment 2 (Magnetic Induction Particle Detection Device)

[0085] FIG. 2 is a schematic view showing the structure of a second preferred embodiment of the magnetic induction particle detection device of the present invention; this embodiment differs from the above-mentioned embodiment 1 in that: as shown in FIG. 3, a spacer ring sleeve 6 is further arranged between the excitation coil and the induction coils in the detection device, that is, the excitation coil is sleeved with a spacer ring sleeve, and the induction coils are wound around the spacer ring sleeve. And a shielding ring 7 is arranged outside the induction coil.

[0086] Both or one of the above technical solutions can be implemented as required. In this embodiment, both solutions are implemented, that is, a spacer ring sleeve and a shielding ring are arranged, which is a more preferred embodiment.

[0087] The arrangement of the spacer ring sleeve, on one hand, is mainly used for isolating the excitation coil and the induction coils during winding in the production and manufacturing process, and on the other hand, the spacer ring sleeve can be used meanwhile as a frame around which the induction coils are wound, thus the flatness of the induction coil winding can be improved. Further preferably, the spacer ring sleeve is made of a non-magnetic conductive material, the magnetic field loss between the induction coils and the excitation coil is minimized as much as possible in the process of responding to the magnetic field disturbance generated by the metal particles, which is advantageous to improving the detection accuracy of the metal particles, and therefore the non-magnetic conductive material is selected herein.

[0088] The arrangement of the shielding ring outside the induction coil can isolate the external magnetic field, prevent the interference of the external magnetic field, thus rendering a more accurate detection result and a better detection effect.

[0089] With reference to FIGS. 4 and 5, taking the arrangement in the above-described embodiment as an example, the implementation principle of the device will be described hereinafter as follows:

[0090] An alternating magnetic field can be generated by inputting a sinusoidal alternating signal at two ends of the excitation coil; under the action of an alternating magnetic field, alternating signals can be generated at two ends of the induction coil.

[0091] Depending on the magnetic conductivity of the material, metal materials can be roughly classified as diamagnetic (<1), paramagnetic (>1), and ferromagnetic (>>1). The diamagnetic material weakens the magnetic field, the paramagnetic material strengthens the magnetic field, and the ferromagnetic material greatly increases the magnetic field strength. In a circuit, opposite output ends of the two induction coils are connected, and output signals of the other two ends are measured. When no metal particles pass through the interior of the excitation coil, induction signals of the two induction coils cancel out each other, thus the overall output of the system is zero. When metal particles (ferromagnetic materials) pass through the interior of the excitation coil from left to right, the process is divided into the following stages:

[0092] (1) When the metal particles enter the first induction coil, the change of the first induction coil is relatively sensitive, and firstly the voltage value rises, but the change of the second induction coil is relatively slow, therefore, at the moment, the two ends of the induction coil output a rising positive voltage;

[0093] (2) Along with the metal particles approaching the middle, the second induction coil is also influenced, at the moment, the voltage generated by the first induction coil is slowly balanced by the voltage generated by the second induction coil and gradually decreases, and then decreases to zero in the middle of the first induction coil and the second induction coil;

[0094] (3) The metal particles pass through the first induction coil and enter the second induction coil, at the moment, the voltage value of the second induction coil is higher than that of the first induction coil, a negative voltage appears, and the voltage amplitude is continuously increasing;

[0095] (4) When the particles pass through the second induction coil and flow out of the second induction coil, the influence on the second induction coil is slowly weakened, the voltage amplitude is slowly decreasing and then approaches zero when the particles leave the second induction coil behind for a certain distance.

[0096] According to the electromagnetic induction principle, when metal particles pass through the lubricating oil pipeline from left to right, the sensor equipment can detect a signal similar to a sinusoidal wave, the amplitude of the signal is proportional to the size of the particles, and the period of the signal is proportional to the flow velocity of the particles, on such a basis, the flow velocity is calculated.

Embodiment 3 (Concentration Detection Method Applying the Magnetic Induction Particle Detection Device)

[0097] This embodiment provides a detection method applying the magnetic induction particle detection device mentioned above, comprising the steps of:

[0098] S1: acquiring an output signal of the signal detection system to obtain a voltage amplitude change;

[0099] S2: detecting the metal particle concentration according to the obtained voltage amplitude change;

[0100] Wherein the voltage amplitude change comprises changes of voltage amplitude and time, namely the relationship between the voltage amplitude change and the time, such as the voltage amplitude at a certain time.

[0101] In a preferred embodiment, detecting the metal particle concentration comprises the steps of:

[0102] obtaining the flow velocity v of the metal particles passing through the induction coils;

[0103] obtaining the mass m of the metal particles; and

[0104] calculating the concentration of the particles c on the basis of the flow velocity v of the metal particles, the mass m of the metal particles, the elapsed time t and the cross-sectional area S of the pipeline by using the following formula:

[00004] $c = \frac{m}{v t S}$

[0105] In a more preferred embodiment, the method of obtaining the metal particle flow velocity v comprises the steps of:

[0106] Respectively recording the times when the voltage amplitude of the metal particles passing through a group of induction coils measured by the signal detection system is at the highest point and at the zero point during the positive half cycle, and calculating the time difference value T.sub.1 and the length L.sub.1 of the corresponding induction coils; respectively recording the times when the voltage amplitude, measured by the signal detection system, is at the zero point and at the highest point during the negative half cycle, and calculating the time difference value T.sub.2 and the length L.sub.2 of the corresponding induction coils; and

[0107] Obtaining the flow velocity according to this formula:

[00005] $v = \frac{\frac{k_{1} L_{1}}{.Math. .Math. T_{1}} + .Math. \frac{k_{2} L_{2}}{.Math. .Math. T_{2}}}{2}$

[0108] Due to the fact that detection points at zero points are too many in the output signal, errors are likely to be caused in an actual sampling process; therefore, in this method, the highest points of the positive half cycle and the negative half cycle of the signal is selected as a time recording point to be used for flow velocity analysis.

[0109] In the process that particles flow through the lubricating oil pipeline, the length of the pipeline L is certain, T.sub.1, T.sub.2 and T.sub.3 are sampled, wherein T.sub.1 is the moment when a signal goes by the highest point of the positive half cycle, T.sub.2 is the moment when the signal goes by the zero point, and T.sub.3 is the moment when the signal goes by the highest point of the negative half cycle, as shown in FIG. 5; the flow velocity can be obtained by time sampling:

[00006] $v = K \frac{L}{.Math. .Math. T}$

[0110] Because different factors, such as the wire (thickness, material) of each lubricating oil sensor, the number of winding turns and the interaction between the two induction coils affect the output signal, making the sensor fail to sense the middle of the induction coils, the correction coefficient K is introduced to correct the output signal. Meanwhile, analysis is carried out on the basis of two time periods, namely, T.sub.1 to T.sub.2 and T.sub.2 to T.sub.3, and the average flow velocity is taken to reduce errors.

[00007] $v_{1} = K \frac{L}{2 (T_{2} - T_{1})}$ $v_{2} = K \frac{L}{2 (T_{3} - T_{2})}$ $v = \frac{v_{1} + v_{2}}{2}$

Wherein L is the total length through the induction coil, and L/2 is the coil length through two half cycles respectively.

[0111] The above is the calculated velocity of particles passing through one set of induction coils.

[0112] In the output signal, the amplitude of the signal is related to the size of the metal particles. When the cylindrical metal particles pass through the interior of the spiral pipe at a constant speed, the induced electromotive force is calculated as follows:

E=4k.sub.0.sub.rn.sup.3VI.sub.0v

Wherein k is a system correction coefficient, n is the density of a coil, i.e., turn number (winding turns per unit length=total turns/total length), V is a particle volume, and v is a particle flow velocity.

[0113] In a single-layer densely wound coil, the induction voltage E caused when the metal particles pass through the spiral coil induction coil is directly proportional to the volume V, the magnetic conductivity, the passing speed of the particles v, and the third power of the winding density of the coil. Through quantitative analysis on the output signal of the sensor, the volume and the mass of the metal particles flowing through the lubricating oil pipeline can be calculated through conversion. Under the condition that the lubricating oil flow velocity v is obtained, the concentration of metal particles is measured, and the method is as follows:

[0114] With the cross-sectional area S of the pipeline given, by converting the number and size of passing metal particles obtained on the basis of the amplitude value of the output signal in a period t into the total mass m, the concentration of the metal particles is obtained through the following formula:

[00008] $c = \frac{m}{v t S} .Math. (.Math. .Math. .Math. g .Math. / .Math. m^{3})$

[0115] In a further preferred embodiment, the frequency at which the output signal of the signal detection system is acquired in S1 is once per millisecond.

Embodiment 4 (Concentration Detection Method Applying the Magnetic Induction Particle Detection Device)

[0116] This embodiment differs from the embodiment 3 in that calculation of the flow velocity of this embodiment adopts a more preferred embodiment, that is, if there are multiple groups of induction coils, the flow velocity v at which the metal particles pass through the induction coils is an average value of the flow velocities of all the groups of induction coils.

[0117] For example, the flow velocity vgn (wherein n is a positive integer) of the metal particles passing through the nth group of induction coils is respectively calculated in the S1, and the flow velocity v is the average value of the flow velocities of all the groups of induction coils, namely:

[00009] $v = \frac{v_{g .Math. .Math. 1} + v_{g .Math. .Math. 2} + .Math. + v_{gn}}{n}$

[0118] The calculation accuracy of the flow velocity can be improved by an averaging method, and the detection result is more accurate.

[0119] For example, in the device, there are two groups of induction coils in total, the flow velocity measured for the first group of induction coils is vg1, the flow velocity measured for the second group of induction coils is vg2, and then the flow velocity finally calculated in S1 can be obtained by the following formula:

[00010] $v = \frac{v_{g .Math. .Math. 1} + v_{g .Math. .Math. 2}}{2}$

[0120] Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word about or approximately in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice; material, manufacturing, and assembly tolerances; and testing capability.

[0121] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean at least one of A, at least one of B, and at least one of C.

[0122] The above-described embodiments are merely preferred embodiments of the present invention, and thus do not limit the scope of the present invention, and any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention are intended to be within the scope of the present invention.

MAGNETIC INDUCTION PARTICLE DETECTION DEVICE AND CONCENTRATION DETECTION METHOD

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Cpc classification

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G01N2015/0053

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G01N2015/0003

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G01N2015/0687

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G01N2015/1027

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G01N33/2858

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G01N15/0656

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G01N15/06

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Abstract

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