New On-Line MFL Testing Method and Apparatus for Winding Mine Hoist Wire Rope

Round 1

Reviewer 1 Report

1. Authors should improve the abstract (add results, conclusion and discussion).
2. Authors should review the reference style in text and fix the text separation from previous word.
3. Figures caption  number is not consecutive.
4. reference list should be improved

Author Response

Dear Reviewer,

Thank you for your email and the reviewer’s comments concerning our manuscript entitled “New On-line MFL Testing Method and Apparatus for Winding Mine Hoist Wire Rope” (Manuscript ID: applsci-1635094). We thank the reviewer for the very helpful comments. We revised the manuscript according to the recommendations. We provide below with a brief “List of changes” in the revised manuscript, followed by our answers to the referee’s comments.

List of changes:

The authors discovered further problems with the previously designed experimental device during the revision process, so a new on-line inspection device was constructed for detecting damage to wire ropes operating at high speeds, and experimental and on-site validation was undertaken.

 

1. We revised the abstract in order to provide an on-line inspection device with a motor, rocker and probe coordinated, which can be used for on-site testing of WMH wire ropes.
2. We modified Section 1 introduction to clarify that magnetic flux leakage (MFL) testing is the most effective method for detecting defects in wire ropes and to describe work undertaken in the literature on optimizing the structure of the MFL detection device and the magnetic sensitive sensor in order to improve their performance.

 

3. We added 3.1. Open-loop permanent magnetizer and compared its performance with other probes in terms of magnetic suction force, as well as analyzing whether the new probe is able to reduce the suction force between the probe and the wire rope.

 

4. 3.3. Signal Characterization and 3.4. Preliminary Experimental Verification has been added to explore and analyze in-depth the variation of the curve characteristics of the leakage field of defects and to perform experimental verification.
5. In Section 4. Key techniques of the method, a set of in-line inspection devices was redesigned in which the lifting motor and rocker are coordinated with an inspection probe opened and closed by a clutch, and the operating principle of the probe floating to track the vibration and oscillation of the wire rope was described.

 

6. We revised the reference format.

Comment 1: Authors should improve the abstract (add results, conclusion and discussion).

Response to comment 1: We have revised the abstract to design structural dimensions for an open-loop permanent magnetizer simulation analysis and designed an on-line nondestructive device and successfully applied it to on-site testing of WMH wire ropes.

 

Comment 2: Authors should review the reference style in text and fix the text separation from previous word.

Response to comment 2: The reference style in text and the text have been modified.

 

Comment 3: Figures caption number is not consecutive.

Response to comment 3: The figure caption numbers have been modified.

 

Comment 4: reference list should be improved.

Response to comment 4: The reference list should be improved.

 

We thank the reviewer and remain at your disposal for any further questions.

Yours sincerely,
Xiaoyuan Jiang

Author Response File: Author Response.docx

Reviewer 2 Report

The authors presented a new apparatus they designed for defect detection of MWH wire rope in service. They provided sufficient background information relating to the current testing methods as well as the NDT challenges for MWH wire rope. The key techniques of the new apparatus and testing methods is well explained and the application of it in a mine hoist field is convincing. Several comments and suggestions for further improvement are listed below.

 

Section 1 Introduction:

• Line 61: please specify what is the “on-site environment’s interference”.

Section 3 Analysis of the novel probe

• The numbering of figures in section 3 is confusing. They are inconsistency in the text and in the captions.
• The figures presented from section 3.1 to 3.5 need to be explained in more details. E.g., what is the key message of each figure shown here and/or why it is important?
• Can the author add information on comparing the performance of their new probe with other existing probes?
• How long is the regular replacement cycle for traditional steel wire rope? What is the estimated service life of this new probe?

Section 6 Discussion

• Lines 328-330 “Although the requirements that multi-ropes should be detected simultaneously are needed, the design of the new apparatus is applicable compared with the traditional testing equipment 27, 28.” Can the authors elaborate more on the traditional testing equipment shown in references [27-28] and how they conclude that their design of the new apparatus is applicable?
• Should there be a Conclusion section?

Author Response

Dear Reviewer,

Thank you for your email and the reviewer’s comments concerning our manuscript entitled “New On-line MFL Testing Method and Apparatus for Winding Mine Hoist Wire Rope” (Manuscript ID: applsci-1635094). We thank the reviewer for the very helpful comments. We revised the manuscript according to the recommendations. We provide below with a brief “List of changes” in the revised manuscript, followed by our answers to the referee’s comments.

List of changes:

The authors discovered further problems with the previously designed experimental device during the revision process, so a new on-line inspection device was constructed for detecting damage to wire ropes operating at high speeds, and experimental and on-site validation was undertaken.

 

1. We revised the abstract in order to provide an on-line inspection device with a motor, rocker and probe coordinated, which can be used for on-site testing of WMH wire ropes.
2. We modified Section 1 introduction to clarify that magnetic flux leakage (MFL) testing is the most effective method for detecting defects in wire ropes and to describe work undertaken in the literature on optimizing the structure of the MFL detection device and the magnetic sensitive sensor in order to improve their performance.

 

3. We added 3.1. Open-loop permanent magnetizer and compared its performance with other probes in terms of magnetic suction force, as well as analyzing whether the new probe is able to reduce the suction force between the probe and the wire rope.

 

4. 3.3. Signal Characterization and 3.4. Preliminary Experimental Verification have been added to explore and analyze in depth the variation of the curve characteristics of the leakage field of defects and to perform experimental verification.
5. In Section 4. Key techniques of the method, a set of in-line inspection devices was redesigned in which the lifting motor and rocker are coordinated with an inspection probe opened and closed by a clutch, and the operating principle of the probe floating to track the vibration and oscillation of the wire rope was described.

 

6. We revised the reference format.

Comment 1: Section 1 Introduction: Line 61: please specify what is the “on-site environment’s interference”.

Response to comment 1: The on-site environment’s interference specifically refers to the fast running speed of the wire rope on site, which can cause jitter and oscillation and cause wear between the wire rope detection sensor and the wire rope, which we have explained and modified in detail in Section 1. Introduction: Line 62.

 

Comment 2: Section 3 Analysis of the novel probe: The numbering of figures in section 3 is confusing. They are inconsistency in the text and in the captions.

Response to comment 2: Figures caption number have been modified。

 

Comment 3: Section 3 Analysis of the novel probe: The figures presented from section 3.1 to 3.5 need to be explained in more details. E.g., what is the key message of each figure shown here and/or why it is important?

Response to comment 3: Section 3. Analysis of the novel probe: within sections 3.1 to 3.5, the emphasis is on the variation pattern of the defect leakage curves in different directions for the L, H, OD, and ID variables, and the addition of 3.3. Signal Characterization, which examines several important features of the curves for different variables, to study the defect information in depth.

 

Comment 4: Can the author add information on comparing the performance of their new probe with other existing probes?

Response to comment 4: we added 3.1. open-loop permanent magnetizer to compare the performance of the new probe with other probes in terms of magnetic suction, the new probe is able to reduce the suction and friction between the probe and the wire rope and is able to adapt to the relative movement with the wire rope.

 

Comment 5: How long is the regular replacement cycle for traditional steel wire rope? What is the estimated service life of this new probe?

Response to comment 5: According to coal mine safety regulations, friction wheel hoisting wire ropes may not be used for more than two years. It is generally agreed that the service life of the probe does not have a specific date. Generally, the probe inner surface and wire rope outer surface distance should be large, so as to reduce friction between the two, thus extending the life of the probe, as stated in the literature ‘Non-Destructive Detection of Wire Rope Discontinuities from Residual Magnetic Field Images Using the Hilbert-Huang Transform and Compressed Sensing’.

 

Line 194 also elaborates: ‘The lifting distance is the distance between the magnetic sensing element and the surface of the wire rope. In general, the amplitude of the detection signal decreases rapidly with the increasing lifting distance, so the lifting distance is usually chosen to range from 2-10 mm [19,29-30], however, the lifting height should be as high as possible in order to prevent friction between the device and the wire rope, thus extending the probe's service life, and a height of 5 mm has been used in this study.’.

 

Comment 6: Section 6 Discussion: Lines 328-330 “Although the requirements that multi-ropes should be detected simultaneously are needed, the design of the new apparatus is applicable compared with the traditional testing equipment 27, 28.” Can the authors elaborate more on the traditional testing equipment shown in references [27-28] and how they conclude that their design of the new apparatus is applicable?

Response to comment 6: The point we are trying to make is that the designed on-line testing device can be manufactured as several identical devices and designed as one to detection multiple ropes, as restated in Section 6. Conclusion Line 390：’A study of the results of the experiments revealed that the newly invented apparatus per-formed well for on-line testing of wire rope, and this device can be expanded into multiple groups of the same device for detecting the requirements of multiple ropes.’.

 

Comment 7: Should there be a Conclusion section?

Response to comment 7: The article has been restructured and revised to Section 6. Conclusion。

 

We thank the reviewer and remain at your disposal for any further questions.

Yours sincerely,
Xiaoyuan Jiang

Author Response File: Author Response.docx

Reviewer 3 Report

The major contribution of the manuscript is the proposed an on-line magnetic flux leakage (MFL) testing method for inspection of wire ropes used in winding mine hoist (WMH). In order to effectively detect MFL, the authors propose a novel probe mechanism to guarantee that the probe could detect wire rope defects without interfering; meanwhile, the authors present the analysis of the design and the actual experimental results to verify its feasibility. The manuscript is well-written, interesting, and useful contribution, the tables and figures are of high quality, and the authors have clearly worked hard to produce reasonable and promising results and detailed description of the methodology. I think the manuscript is entirely suitable for publication in applied sciences, but the manuscript needs a few of proof-reading as the following:

1) There is an extra period at the end of many sentences in this manuscript, please correct.

2) In Section 3 and Section 6, lines 108, 113, 114 and 330. Please put square brackets when citing references.

3) Line 120, “… advantages such as small volume, lightweight, strong commonality, Etc.” should be corrected as “… advantages, such as small volume, lightweight, and strong commonality.”

4) Line 134, “…, Rare is the …” should be corrected as “…, Rair is the …” In similar situations, it is recommended that the notation used in text should be consistent with that used in equations, such as Rleft and Rright in Lines 139 and 140.

5) Lines 134 and 139, “Where…” should be corrected to “where …” and move to the beginning of the sentence.

6) Line 147, “… the magnetic dissipation rate   of the …” should be corrected as “… the magnetic dissipation rate λ of the …”

7) References should be revised into a consistent format, especially the journal name needs to be abbreviated.

Author Response

Dear Reviewer,

Thank you for your email and the reviewer’s comments concerning our manuscript entitled “New On-line MFL Testing Method and Apparatus for Winding Mine Hoist Wire Rope” (Manuscript ID: applsci-1635094). We thank the reviewer for the very helpful comments. We revised the manuscript according to the recommendations. We provide below with a brief “List of changes” in the revised manuscript, followed by our answers to the referee’s comments.

List of changes:

The authors discovered further problems with the previously designed experimental device during the revision process, so a new on-line inspection device was constructed for detecting damage to wire ropes operating at high speeds, and experimental and on-site validation was undertaken.

 

1. We revised the abstract in order to provide an on-line inspection device with a motor, rocker and probe coordinated, which can be used for on-site testing of WMH wire ropes.
2. We modified Section 1 introduction to clarify that magnetic flux leakage (MFL) testing is the most effective method for detecting defects in wire ropes and to describe work undertaken in the literature on optimizing the structure of the MFL detection device and the magnetic sensitive sensor in order to improve their performance.

 

3. We added 3.1. Open-loop permanent magnetizer and compared its performance with other probes in terms of magnetic suction force, as well as analyzing whether the new probe is able to reduce the suction force between the probe and the wire rope.

 

4. 3.3. Signal Characterization and 3.4. Preliminary Experimental Verification have been added to explore and analyze in depth the variation of the curve characteristics of the leakage field of defects and to perform experimental verification.
5. In Section 4. Key techniques of the method, a set of in-line inspection devices was redesigned in which the lifting motor and rocker are coordinated with an inspection probe opened and closed by a clutch, and the operating principle of the probe floating to track the vibration and oscillation of the wire rope was described.

 

6. We revised the reference format.

 

Comment 1: There is an extra period at the end of many sentences in this manuscript, please correct.
Response to comment 1：We've made the changes.

 

Comment 2: In Section 3 and Section 6, lines 108, 113, 114 and 330. Please put square brackets when citing references.

Response to comment 2：Citations have been modified.

 

Comment 3: Line 120, “… advantages such as small volume, lightweight, strong commonality, Etc.” should be corrected as “… advantages, such as small volume, lightweight, and strong commonality.”

Response to comment 3：We've made the changes.

 

Comment 4: Line 134, “…, Rare is the …” should be corrected as “…, Rair is the …” In similar situations, it is recommended that the notation used in text should be consistent with that used in equations, such as Rleft and Rright in Lines 139 and 140.

Response to comment 4：We have made changes in Line 164.

 

Comment 5: Lines 134 and 139, “Where…” should be corrected to “where …” and move to the beginning of the sentence.

Response to comment 5：We have made changes in Line 164 and 167。

 

Comment 6: Line 147, “… the magnetic dissipation rate of the …” should be corrected as “… the magnetic dissipation rate λ of the …”

Response to comment 6：We have made changes in Line 176。

 

Comment 7: References should be revised into a consistent format, especially the journal name needs to be abbreviated.

Response to comment 7：We've made the changes.

 

We thank the reviewer and remain at your disposal for any further questions.

Yours sincerely,
Xiaoyuan Jiang

Author Response File: Author Response.docx

Reviewer 4 Report

The subject is interesting and the paper gives a non destructive solution for a complex situation. The paper is quite  too short, it should be developped to give more results and a deeper discussion between theory and real signals. There are several changes suggested in the joined file. Most of them are minor. 

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

Thank you for your email and the reviewer’s comments concerning our manuscript entitled “New On-line MFL Testing Method and Apparatus for Winding Mine Hoist Wire Rope” (Manuscript ID: applsci-1635094). We thank the reviewer for the very helpful comments. We revised the manuscript according to the recommendations. We provide below with a brief “List of changes” in the revised manuscript, followed by our answers to the referee’s comments.

List of changes:

The authors discovered further problems with the previously designed experimental device during the revision process, so a new on-line inspection device was constructed for detecting damage to wire ropes operating at high speeds, and experimental and on-site validation was undertaken.

 

1. We revised the abstract in order to provide an on-line inspection device with a motor, rocker and probe coordinated, which can be used for on-site testing of WMH wire ropes.
2. We modified Section 1 introduction to clarify that magnetic flux leakage (MFL) testing is the most effective method for detecting defects in wire ropes and to describe work undertaken in the literature on optimizing the structure of the MFL detection device and the magnetic sensitive sensor in order to improve their performance.

 

3. We added 3.1. Open-loop permanent magnetizer and compared its performance with other probes in terms of magnetic suction force, as well as analyzing whether the new probe is able to reduce the suction force between the probe and the wire rope.

 

4. 3.3. Signal Characterization and 3.4. Preliminary Experimental Verification have been added to explore and analyze in depth the variation of the curve characteristics of the leakage field of defects and to perform experimental verification.
5. In Section 4. Key techniques of the method, a set of in-line inspection devices was redesigned in which the lifting motor and rocker are coordinated with an inspection probe opened and closed by a clutch, and the operating principle of the probe floating to track the vibration and oscillation of the wire rope was described.

 

6. We revised the reference format.

Comment 1: This term 'yoke structure' should be more explained, perhaps make a link with fig 2 ?

Response to comment 1：Link to Figure 4, which has been rewritten from ‘yoke structure’ to ‘core’.

 

Comment 2: You have to precise what is BP？

Response to comment 2：Section 1. Introduction Line 39：The references have been adjusted and the literature related to BP processing has been removed, in order to more accurately reflect the research conducted in the previous literature to improve the performance of the MFL testing device and magnetic sensor. These improvements include the optimal design of the structure of the testing device and magnetic sensor.

 

Comment 3: Precise what it is, the material and the thickness range of this protection

Response to comment 3：Already modified in Line 84, the surface of the wire rope needs to be protected with oil, in order to reduce the friction between the rope and the sheave groove or other surfaces during use, as well as to protect it from corrosion.

 

Comment 4: ‘Wire rope and its attachments are in closed-loop rotary structures, the probe must be able to put backward and forwards from it, while any 360° closed-loop structure and device (including the incentive and receiving devices) fails;’ fail?  I don't understand, could you rewrite this sentence?

Response to comment 4：Modify it to:‘(1) Probes must be able to open and hold wire ropes for closed-loop structures, there-fore 360-degree closed-loop structures and devices (including excitation and receiving de-vices) are not available;’ in Line 94.

 

Comment 5: equation (2) is useless ?

the size of equations should be uniform and spaces are required between paragraphs and equations for clarity

Response to comment 5：Already modified from Line 166.

 

Comment 6: Quality of figure 1 and 2 is low?

Response to comment 6：The images have all been modified.

 

Comment 7: probes A and B are not represented, ant correspondence with magneto-sensor? Complete the figure or develop the text describing these two figures.

Response to comment 7：Already modified to Fig. 4, with changes in Line 146, ‘An open-loop magnetizer is a split structure composed of two identical axially magnetized rings, probe A and probe B, one of which consists of two magnets and a magnetic core to act as a magnetization circuit.’.

 

Comment 8: ‘As equation (8) shows, it could be concluded that to decrease the magnetic dissipation rate and increase the magnetic saturation rate.’ this sentence is not 'finished', read again this paragraph to propose a clearer sentence.

Response to comment 8：We modified in Line 175,’ As equation (6) shows the ratio of the flux leakage in the air by the excitation source to the total flux provided by the excitation source, in order to reduce the flux leakage in the air, it is necessary to reduce the magnetic dissipation rate λ, i.e., to increase the flux inside the specimen and increase the magnetic saturation rate. The reluctance of R_air should be increased or the parameters of R_left, R_right, and _Rspecimen should be decreased. As a result, the magnetic energy of the permanent magnet could be fully used.’.

 

Comment 9: ‘For designing the open-loop permanent magnet detection sensor,’ describe more precisely the novelty, what about the gap between the two parts? is it what characterizes the word 'open’? Could you indicate the distance between the two parts, is it a parameter of the finite element model? what about its importance?

Response to comment 9：In Line 146 and Line 186, the open-loop magnetizer is a split structure consisting of two identical axial magnetizing rings, Probe A and Probe B. The gap between the upper and lower magnetizing rings is 4 mm, which facilitates machining and assembly.

 

Comment 10: ‘the magnetic induction intensity (axial component and radial component) was extracted along the axial direction at the height of 5 mm from the defect center of the steel bar surface’ Is there any reason to justify this value? Why not 4 or 6 mm ?

Response to comment 10：The usual lifting distance is between 2 and 10 mm, we increased the distance between the device and the rope while keeping the amplitude of the detection signal as high as possible, finally choosing 5 mm, as described in Line 196,’In general, the amplitude of the detection signal decreases rapidly with the increasing lifting distance, so the lifting distance is usually chosen to range from 2-10 mm [19,29-30], however, the lifting height should be as high as possible in order to prevent friction between the device and the wire rope, thus extending the probe's service life, and a height of 5 mm has been used in this study.’.

 

Comment 11: The color scale is not readable.

Response to comment 11：Modifications have been made in Figure 6.

 

Comment 12: This angle delta is not shown in the figures!

It is not possible to understand this part.

You have to be more precise.

Perhaps the general sketch in figure 19 should be introduced first to help the readers to follow kinetic sketches

Response to comment 12：In section 4. Key techniques of the method，We have redesigned the on-line testing device and probe structure and illustrated the angles θ and δ in Figure 1.

 

Comment 13: No 'theoretical signals' were displayed in the first part of the article; you have to make the link between these signals and figure you produced in the first part.

Response to comment 13：In 3.4. Preliminary experimental verification, the experimental signal is linked to the simulated signal. The on-line testing device, designed after sizing, was installed into the on-site conditions of a high-speed running wire rope and the damage signal was detected as in Figure 20.

 

We thank the reviewer and remain at your disposal for any further questions.

Yours sincerely,
Xiaoyuan Jiang

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

table 1, table 2, and figure 12 should be not segmented.
A proposal should be done.

figure 14 is not referenced in the body text

the figure 19 label is not wright

Author Response

Dear Reviewers,

Thanks very much for taking your time to review this manuscript. I really appreciate all your comments and suggestions! Please find my itemized responses below and my revisions which are marked in red in the resubmitted files.

Thanks again!

Comment 1:  Table 1, table 2, and figure 12 should be not segmented. A proposal should be done. 

Response to comment 1:  Table 1, Figure 12 and Figure 15 have been adjusted to avoid other figures and tables being segmented.  

Comment 2: Figure 14 is not referenced in the body text.

Response to comment 2: Reference to Figure 14 added to line 279, page12, ‘Figure 14 shows two different types of damage on a wire rope with multiple broken wires and a single broken wire.’.  

Comment 3: the figure 19 label is not wright.

Response to comment 3: The label is amended to ‘Figure 19. Installation of the device: (a) installation principle of the device; (b) on-site installation’.