Review Reports

Round 1

Reviewer 1 Report

This manuscript deals with the important field of NOx formation in rotary kilns and aims to improve the CFD modelling efforts of thermal NOx specifically. 

The paper can be published after minor revision.

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Comments:

1. Radiation. Please motivate, and, clarify that only gaseous radiation is included in the radiative transport. For example: soot was omitted due to the high air to fuel ratio in the flame and the occurrence of soot is unlikely to have any significant impact on the radiative exchange. 
2. NOx modelling. A)Please clarify how this work relates and is based on previous work in ref 8. B) Please clarify how residence time is accounted for in the post processing of the NOx chemistry. C) Please clarify the species included in the NOx scheme and how radical chemistry is accounted for
3. Figures 5,6,7 and 9: specify the units in the legend or in the Figure captions
4. Conclusions: there is a sentence that is incorrect: "The study of the aerodynamics of the kin improved our understanding of how the thermal NOx formation. 
5. Conclusions & abstract: clarify the studied design measures and how this affects the thermal NOx production in the paper. The results are interested and should be brought to the readers attention in both the abstract and conclusion segments.

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Author Response

Please see the attachment.

 

Reviewer 2 Report

The manuscript "Thermal mitigation of NOx by modifying the secondary air injection channel: a case study in the cement industry" is generally well written, there are typing errors, plus the figures with different styles do not help the reader in understanding the results which are very interesting. I therefore recommend a careful reading of the manuscript and an expansion of some sections indicated in the review document.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf