Performance Analysis of a Hybrid Dehumidification System Adapted for Suspension Bridge Corrosion Protection: A Numerical Study

Round 1

Reviewer 1 Report

-          The topic is interesting and the manuscript was well-organized.

  The research gap that the manuscript covers is not clearly addressed.

  English language needs moderate editing. i.e.  “However, suspension bridges are exposed to severe and rapidly changing temperature and humidity, DWDS are often unable to meet peak wet loads, especially in summer”.

  In Fig 3, the fan on the top left is not properly labeled.

 The system description of the HDS is hard to follow in Fig 4. Please show the process sequence on Fig 3 as well.

Author Response

We feel great thanks for your professional review work on our article. As you are concerned, there are several problems that need to be addressed. According to your nice suggestions, we have made corrections to our previous draft. All changes were marked in red using the “Track Changes” function in the revised manuscript. The latest manuscript is attached. Detailed corrections are listed below.

 

1. The research gap that the manuscript covers is not clearly addressed.

Revision explanation:

Thanks a lot for your advice. We summarize the gaps and shortcomings of previous studies. The innovations of this paper are discussed in more detail. These can be found in the second paragraph on page 3 of the latest manuscript

 

 

2. English language needs moderate editing. i.e.  “However, suspension bridges are exposed to severe and rapidly changing temperature and humidity, DWDS are often unable to meet peak wet loads, especially in summer”.

Revision explanation:

Thanks for your suggestion. As suggested by the reviewer, we have corrected the “However, suspension bridges are exposed to severe and rapidly changing temperature and humidity, DWDS are often unable to meet peak wet loads, especially in summer” into “However, DWDS are often unable to meet peak wet loads due to the severe and rapidly changing temperature and humidity in summer”.

 

3. In Fig 3, the fan on the top left is not properly labeled.

Revision explanation:

We sincerely thank the reviewer for careful reading. This error has been corrected.

 

4. The system description of the HDS is hard to follow in Fig 4. Please show the process sequence on Fig 3 as well.

Revision explanation:

Thanks for your good idea. We have marked up the process sequence according to your comment.

 

Thanks a lot for your excellent advice. We have corrected it according to your advice. Thanks again for all your comments which are very helpful for us!

Author Response File: Author Response.pdf

Reviewer 2 Report

This manuscript deals with a processing module to control the water content of a flow of air applied to the internal interstices of bridge cables so that to maintain safe conditions to continuously prevent corrosion degradation of metal cables.

 The processing module called hybrid dehumidification system consist of a cycling condensing- evaporating unit using a selected refrigerant that is coupled to a silica-gel desiccant contained in a rotating  wheel.  The  condensing- evaporating unit fulfil two tasks, on one side partially remove water by an adiabatic cooling (in the condensing section) of a flow of water to  be pumped toward a silica gel bed and then to the bridge cables, and on the other side, add heat a flow of air that further is used for drying humid silica gel; this operation coordinatively takes place while a rotating  wheel containing the silica bed in various compartments  is under operation.  The author claim that this module is a significant upgrade as compared to a simpler one called   desiccant wheel dehumidification system, that is devoid of the cycling condensing- evaporating unit. This claim is demonstrated using numerical calculation out of mass and energy balances.

 

 In my opinion this works is novel and interesting as a corrosion protection system to be applied not only to bridge cables but also to other cables exposed to seawater and underground conditions.  

Unfortunately, the manuscript has many grammatical errors with badly structures sentences that makes this manuscript unsuitable to be published in the current form. Also, the equations need to be reviewed.

 I recommend a mayor revision to upgrade the manuscript to clarify many sentences and described ideas. I attached the pdf manuscript with popup remarks to help in the upgrading work of the manuscript. 

 I suggest considering the accidental situation (that I assume is common) by which the external HDPE sheath of the cable is partially broken, and aqueous electrolyte invades the internal volume interstices. Please add brief comments about how the air pressure (or flow) could be affected, and efficiency of the system.  

 

 

Comments for author File: Comments.pdf

Author Response

We feel great thanks for your professional review work on our article. As you are concerned, there are several problems that need to be addressed. According to your nice suggestions, we have made corrections to our previous draft. All changes were marked in red using the “Track Changes” function in the revised manuscript. The latest manuscript is attached. Detailed corrections are listed below.

 

1. Unfortunately, the manuscript has many grammatical errors with badly structures sentences that makes this manuscript unsuitable to be published in the current form. Also, the equations need to be reviewed. I recommend a mayor revision to upgrade the manuscript to clarify many sentences and described ideas. I attached the pdf manuscript with popup remarks to help in the upgrading work of the manuscript.

Revision explanation:

We sincerely thank the reviewer for careful reading. We tried our best to improve the manuscript and made changes to the manuscript according to the attached PDF. And here we did not list the changes but marked in the revised manuscript. We appreciate for Reviewers’ warm work earnestly and hope that the correction will meet with approval.

 

2. I suggest considering the accidental situation (that I assume is common) by which the external HDPE sheath of the cable is partially broken, and aqueous electrolyte invades the internal volume interstices. Please add brief comments about how the air pressure (or flow) could be affected, and efficiency of the system. 

Revision explanation:

Thank you very much for your good idea. Indeed, in the previous version of this manuscript, there are no specific statement about accidental situation by which the external HDPE sheath of the cable is partially broken. But it is really important and should be stated carefully in this paper. So according to your advice, we added the corresponding contents in section 4.3. During these contents, we illustrate the effects of leakage rate on air flow and the related effects on drying time of main cable and dehumidification efficiency. In addition, we calculated the drying time at a leakage rate of 0.005 to compare it with the drying time at a leakage rate of 0. The detailed information can be seen from those of “When the external HDPE sheath of main cable is partially broken, the dry air will leak outside the main cable. As a result, the air flow in the direction of gas flow gradually decreases, which will reduce the dehumidification efficiency and extend the drying time of the main cable. Therefore, when air leakage is found, the air flow should be appropriately increased to ensure the dehumidification effect”.

 

Thanks a lot for your excellent advice. We have corrected it according to your advice. Thanks again for all your comments which are very helpful for us!

Author Response File: Author Response.pdf