Experimental Investigation and Computational Fluid Dynamic Simulation of Hydrodynamics of Liquid–Solid Fluidized Beds

Why did you use glass beads of 3 different sizes? Did you want to simulate the presence of particular solids used for example in the processes listed above or did they have another role? Then it would be better to justify, give a reason why these elements have been used and especially the characteristic dimensions and their density

 We appreciate the reviewer’s comments very much. As you commented, The particle size distribution (PSD) is an important property that can influence the hydrodynamics and chemical conversion in fluidized bed system. The objective of this study is to investigate the effect of PSDs of particle on pressure drop (ΔP), minimum fluidization velocity (Umf) and individual phase hold-up. As a research team, we are working on the use of catalyst with diameters ranging from 2 mm to 6 mm, and therefore we need to study these dimensions because there are subsequent studies on the heat and mass transfer coefficient.

Equations and numbering should be reported according to the Journal standard. In addition, some equations should be better written: for example see the 5

As suggested by the reviewer, Equations and numbering have been corrected according to the journal standard.

All parameters in the equations should be described along with the dimensional units: review Eq 11 and 12, they should not go in a table like this. After Eq 11, you will have to say that some parameters like A B etc are given as a function of another parameter etc.

 As the reviewer commented, the equations have been corrected

In the results, when you present a new Figure, the discussion of the results should be inserted after the Figure

As commented by the reviewer, this note has been corrected

. You could choose a symbol to indicate the minimum fluidization rate. Also, you could better discuss Figure 3, no details have been added

As suggested by the reviewer,  this note has been corrected

In Figure 5, you should add the parametric of the last diameter in the caption. Same for Figure 6.

As suggested by the reviewer, this note has been corrected

The table of symbols in the Conclusions section should be removed. Follow the Journal standards to list the parameters

As commented by the reviewer, this note has been corrected

No.

Comments

Response to the reviewer

1.

LSFB abbreviation from the abstract section is not a common one. Please express the idea in extenso and then use the abbreviations.

 We appreciate the reviewer’s comments very much. As you commented, this note has been corrected (red color)

2.

In this paragraph “Liquid-solid fluidized beds (LSFBs) have several advantages including; high mixture rates (temperature homogeneity and efficient solid mixing), greater surface area, and a high fluid/solid relative velocity [2].”, is

not very clear what “high mixtures rates” is referring to. If is probably related with the velocity of a liquid-solid mixture in a fluidized bed, it must be expressed accordingly. Please rephrase.

As suggested by the reviewer, this note has been corrected (red color)

3.

The introduction does not state properly the novelty of the results emphasized in the manuscript.

 As suggested by the reviewer, this note has been corrected (red color)

4.

The way equations (5) and (6) are presented is not clear.

Please rearrange.

As the reviewer commented, the equations have been corrected

5.

Equation (8) should include a partial derivative on the left side of the equal sign. Please correct.

As the reviewer commented, the equation have been corrected

6.

In order to make the simulation section clearer, please provide the minimum configuration of the system on which

the calculations were carried out as well as the software used

for these calculations.

As suggested by the reviewer, this note has been done                       (red color) and figure 2

7.

Titles of the figures should start with capital letters.

As suggested by the reviewer, this note has been corrected

8.

Measurement units representation in table with the symbols should be corrected (i.e. Pa.s is not the right unit for fluid dynamic viscosity).

As suggested by the reviewer, this note has been corrected

9

No clear comparison between modeling and experimental results is provided in the results section, based on numerical results.

As suggested by the reviewer, this note has been done (red color) and figures 11, 12 and 13.

10

The quality of the figures should be drastically improved.

As suggested by the reviewer, this note has been corrected

11

The structure of the manuscript should be improved (Tables interlapping with text sections, equations without proper numbering, several typing errors).

As suggested by the reviewer, this note has been done and corrected

No.

Comments

Response to the reviewer

1.

The scientific side of the article should be clearly indicated.

What's new in this article?

  We appreciate the reviewer’s comments very much. As you commented, The particle size distribution (PSD) is an important property that can influence the hydrodynamics and chemical conversion in fluidized bed system. The objective of this study is to investigate the effect of PSDs of particle on pressure drop (ΔP), minimum fluidization velocity (Umf) and individual phase hold-up. As a research team, we are working on the use of catalyst with diameters ranging from 2 mm to 6 mm, and therefore we need to study these dimensions because there are subsequent studies on the heat and mass transfer coefficient.

2.

Figures 2-6 should be corrected.

As suggested by the reviewer, figures have been corrected according to the journal standard.

3.

The numbers of Equations should be corrected.

 As commented by the reviewer, Equations and numbering have been corrected according to the journal standard.

4.

The reference’s style should be checked and corrected.

As commented by the reviewer, the errors in the format of the references has been corrected, in addition to that, new references have been added.

5.

A table in Conclusions???

As commented by the reviewer, this note has been corrected

6.

Reynolds number in Nomenclature – indexes.

As suggested by the reviewer, this note has been corrected

7.

mi_f (table in Conclusions) or mi_l (Nomenclature) – fluid viscosity?

As commented by the reviewer, this note has been corrected

8.

Generally, the paper should be corrected and well organized.

As suggested by the reviewer, this note has been corrected

No.

Comments

Response to the reviewer

1.

The authors should carefully and thoroughly revise the format of the manuscript to meet the publication requirements before submission.

 We appreciate the reviewer’s comments very much, As commented by the reviewer, this note has been corrected

2.

because of its applications in various process industries, such as fluid catalytic cracking (FCC) and fluidized bed combustion (FBC) in the petroleum industry," like FCC and FBC should belong to gas-solid fluidized bed, right?

Correct, you are right. This note has been corrected as suggested

3.

I could not find the author's description of the simulation mesh in the manuscript.

Right, you can find it now in section (3.1 Simulation Details) and figure 2.

4.

The third part is not part of the Results, and should be put in the second part.

As commented by the reviewer, this note has been corrected

5.

In some figures, I can't find the scale. Please ask the author to revise it carefully

As suggested by the reviewer,  this note has been corrected

6.

For the description of the picture, the author should first describe the content of the picture and then discuss the content of the picture presentation.

As commented by the reviewer, this note has been corrected

7.

Figure 13 is too blurry.

As suggested by the reviewer,  this note has been corrected

8.

The language of the manuscript needs to be greatly improved.

As commented by the reviewer, this note has been corrected

9.

The references cited by the authors are too old. In addition, there are many errors in the format of the references, so please

revise them carefully.

As commented by the reviewer , the errors in the format of the references has been corrected, in addition to that, new references have been added.

No.

Comments

Response to the reviewer

1.

English language and style are fine/minor spell check required.

We appreciate the reviewer’s comments very much. As you commented, This comment has been addressed.

2.

In my opinion, it would be better to remove the frames around the Figures.

As commented by the reviewer, this comment has been modified through the whole manuscript.

No.

Comments

Response to the reviewer

1.

Moderate English changes required.

We appreciate the reviewer’s comments very much. As you commented, This comment has been addressed through the whole manuscript.

2.

Does the introduction provide sufficient background and include all relevant references?

As the reviewer suggested, this comment has been addressed in the introduction section.

3.

Are the results clearly presented?

As the reviewer commented, this comment has been addressed in results section

4.

Are the conclusions supported by the results?

As the reviewer suggested, this comment has been addressed.

5.

"Correspondence:*Correspondence:

lssf25@umsystem.edu", please check.

As the reviewer commented, this comment has been modified.

6.

I couldn't find any keywords?

As the reviewer commented, this comment has been modified on page 1 after the abstract section.

7.

“Abstract: In this study, different hydrodynamic parameters … were investigated using computational fluid dynamics (CFD)” suggested to be changed to ......and individual phase hold-up were investigated using computational fluid dynamics (CFD) and experiment.

As the reviewer suggested, this comment has been addressed and modified in the abstract section on page 1

8.

Currently, the innovative of the article is not reflected in the manuscript. The authors should highlight the innovative of the article in the abstract and introduction. What new methods were used and what new conclusions were obtained?

As the reviewer commented, this comment has been modified on page 1 in the abstract section and in the introduction section.

9.

The authors discuss some of the results of previous research in the introduction, but do not summaries the work cited., For example, key issues that have been under-researched or have received little attention, highlighting the research difficulties and innovation of this article.

As the reviewer suggested, this comment has been addressed and modified in the introduction section as a table that summarize the recent studies in fluidized bed on page 6.

10.

I could not understand what the author was trying to convey in section 1.1 and what it does for the whole article.

As the reviewer commented, in this section and By using equations (5-6), we predict the fluidization performance, since the Gibilaro et al. equation is equal to 0.183 in the present study, and according to this value, we used CFD simulation for a particulate.

11.

I could not find Figure 12

This figure domenstrate comparisons between CFD simulation results and experimental data of solid holdup for particles diameter of 4 mm: (A) solid holdup for different superficial liquid velocities: (B) solid holdup for different superficial liquid velocities with percent error on page 19.

12.

In Figures 11 and 13, why did the author separate A and B. What is the difference in the meaning that the two figures are trying to convey.

Figures (11A-13A) demonstrate the comparisons between CFD simulation results and experimental data of solid holdup for 3,4 and 6 mm particle size, whereas Figures (11B-13B)  maintained comparisons between CFD simulation results and experimental data of solid holdup with percent error.

13.

Figure 17 is too low quality, please change it.

As the reviewer commented, this comment has been modified.

No.

Comments

Response to the reviewer

1.

In the author'sresponse, I was not able to find the page19 mentioned by the author.

Because of the use of the magazine's format in organizing the search, there is a new pagination, and thus the number of the specified page has become (13), which contains figure (12).

2.

I still haven't found Figure 12, so I would ask the author to double check that the title note of figure 11-13 is not clearly labelled.

As the reviewer commented, this comment has been modified and it is now on page 13.

3.

The layout of figures 16-17 is too disorganised. I suggest that the author re-arrange the layout and add some necessary notes as appropriate.

As the reviewer commented, this comment has been modified.

4.

I believe that figures 11-13 in the manuscript, figures A and B, convey similar meanings, and that figure B alone illustrates the meaning the author intended to convey, so I would ask the

author to check.

As the reviewer suggested, this comment has been modified and it is now on page 13.