Experimental Investigations of Effective Thermal Conductivity of the Selected Examples of Steel Porous Charge
Round 1
Reviewer 1 Report
The paper by R. Wyczolkowski reports on measurements of effective thermal conductivity of porous charges composed from low-carbon steel long components. The authors described the experimental setup and discussed the data collected for different size, shape and arrangement of the components in the temperature range of 70 to 640 °C.
The manuscript is well written. The description of the experiment, the discussion of experimental data and the conclusions sound good. It will be of interest to readers of Solids and I recommend it for publication in its present form.
Author Response
Reviewer recomended the manuscript for publication in Solids in the present form.
Reviewer 2 Report
This is an interesting work in which the author evaluates the effective thermal conductivity of steel bars with different shapes, porosity and arrangement within the measurement setup. I appreciate the detailed descritpion of the measurement setup and design.
I think the results are interesting. Measuring thermal conductivity is quite complex and the different samples and arrangements used by the authors serve to get a general idea about how they can influence on the measured thermal conductivity value. It seems to me that the contact resistance is the critical parameter as the open bars with substantial porosity more or less similar to the non-hollow bars. Thus, figue 12 and 13 seems to suggest there is no change in the measured value beyond a certain "porosity" or open space. However, figure 13 makes me think whether the measurement is truly reliable in those situations with mostly open space between the hot plates, as there seem to be no variation with temperature. I think this particual point deserves a bit more detailed discussion.
On the minus, I feel the writing is a bit rushed and substantial english editing is required. I recommend the text to be substantially revised, especialy the abstract which is a bit muddled.
Author Response
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Author Response.pdf
Reviewer 3 Report
The paper deals with an industrial problem of evaluating the equivalent conductivity coefficient of stacks of steel bars. The problem is important for the steel industry. A good evaluation of the coefficient should help in energy saving.
I understand the subject concerns the conductivity coefficient. However, I think should be explained the heat capacity as well. I guess it is left for further research. However, a comment on it should be given in the paper.
In my opinion, the paper can be published in the Journal. However, a reference to the problem mentioned above should be given.
Author Response
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Reviewer 4 Report
Referee report on the manuscript: “Experimental investigations of effective thermal conductivity of the selected examples of steel porous charge” by Rafał Wyczółkowski
The authors presents the results of experimental investigations of effective thermal conductivity of the porous charge which is composed from various types of steel long components. Hot plate apparatus was used to carry out the measurement for sixteen different samples in the temperature range of 70-640oC. The porosity of the samples, which depending on the type of components used, was ranging from 0.03 to 0.85. Depending on these factors, the effective thermal conductivity ranged from 1.75-8.19 W-m-1.K-1. This accounts for from 0.03 to 0.25 of the value of thermal conductivity of the solid phase of the charge, which in the described cases was low-carbon steel. It was found that effective thermal conductivity rises linearly with temperature. Intensity of this increase and the value of coefficient kef depend on the transverse dimension of the components that form the charge. The results may represent the basis for validation of various models of effective thermal conductivity with respect to evaluation of thermal properties of the porous charge. The study is an interesting one looking at the objectives. I am really impressed with organization of the work and the presentation of results. However, in my opinion, a minor revision is required before it can be published in Solids due to the comments below;
- Check and correct some minor grammar errors.
- I suggest the inclusion of the reference below;
Edet, C. O., Ushie, P. O., & Ekpo, C. M. (2017). Effect of additives on the thermal conductivity of loamy soil in cross river university of technology (crutech) farm, Calabar, Nigeria. Asian Journal of Physical and Chemical Sciences, 1-8.
I recommend the paper for acceptance after minor corrections.
Author Response
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Author Response File: Author Response.pdf
