Mechanism of Particle Agglomeration for Single and Multi-Nozzle Atomization in Spray Drying: A Review

Round 1

Reviewer 1 Report

Paper deals with important task. The authors reviewed a experimental works and experimentally validated theoretical models on the effect of nozzle system configuration on mechanism the particles agglomeration in spray drying.

Paper has great practical value.

It has a logical structure all necessary sections. The paper is technically sound.

Suggestions:

1. The introduction section should be extended using more applied areas according to the paper aim. "Producing the powder with controlled particle size distribution (PSD) as well as particle shape and structure" are also very important for the Material Sciences - DOI: 10.32604/cmc.2022.022582, DOI: 10.1016/j.procs.2021.07.029
2. It would be good to add clear point-by-point the main contributions (findings) at the end of the Introduction section
3. It would be good to add the remainder of this paper
4. Figure 1 has a 3 references. It should be stated that the authors can use these figure without copyright statement
5. The conclusion section should be extended using: 1) numerical results obtained in the paper; 2) limitations of the conducted review; 3) prospects for future research.
6. A lot of references are outdated. Please fix it using 3-5 years old papers in high-impact journals.

Author Response

Response to the reviewer suggestions:

Thank you for valuable comments to our paper. This is our response to the remarks:

1. The introduction section should be extended using more applied areas according to the paper aim. "Producing the powder with controlled particle size distribution (PSD) as well as particle shape and structure" are also very important for the Material Sciences - DOI: 10.32604/cmc.2022.022582, DOI: 10.1016/j.procs.2021.07.029

Suggested papers do not directly cover the area of atomization with single and multiple-nozzle but we introduced paper DOI: 10.32604/cmc.2022.022582 to the Reference list with an appropriate comment in the text:

Producing the powder with controlled particle size distribution (PSD) as well as particle shape and structure is still a paramount interest of the dairy, instant food, pharmaceuticals, detergents industries and even in production of medical and biological products [3, 4].

 Izonin, I., Tkachenko, R., Gregus, M., Duriagina, Z., Shakhovska, N., PNN-SVM Approach of Ti-Based Powder’s Properties Evaluation for Biomedical Implants Production, Computers, Materials and Continua, 2022 , vol.71, no.3, pp. 5934-5947, DOI: 10.32604/cmc.2022.022582,.

2. It would be good to add clear point-by-point the main contributions (findings) at the end of the Introduction section

We just follow the MDPI Processes paper’s format in which description of the main findings at the end of the Introduction section is not required. The main findings are summarized in the Conclusions section.

3. It would be good to add the remainder of this paper

We are not sure what really means “reminder” of the paper. In our opinion the paper contains all available literature knowledge on experiments of the mechanism of agglomeration during atomization from single and multiple-nozzles. This point is left without changes.

4. Figure 1 has 3 references. It should be stated that the authors can use these figures without copyright statement

Figure 1 was redrawn, no copyright statement needed

5. The conclusion section should be extended using: 1) numerical results obtained in the paper; 2) limitations of the conducted review; 3) prospects for future research.

As this is a review paper based solely on the experimental work or validated experimentally models, no numerical results are reported in the paper. No limitations of the conducted review can be pointed out, all available papers in the databases were collected.

A comment regarding prospects for future work was added to the Conclusion section.

In future work, the research of the effect of spray direction of the nozzles on the mechanism on particle agglomeration, final properties of the products and reduction of the wall deposition in co- and counter-current spray drying will be carried out.

6. A lot of references are outdated. Please fix it using 3-5 years old papers in high-impact journals.

We absolutely agree that the references should be up to date. This is, however, a review paper, so everything which was done in the area of the effect of nozzle position or multiple nozzle atomization on agglomeration mechanism should be described, e.g. Davis et al., patent comes from 1971. We presented both, the latest and earlier papers; we suggest not to remove earlier papers from the Reference list as some information about the base of the process will be lost.

Reviewer 2 Report

The submitted manuscript presents a review on the single and multi-nozzle atomization in spray drying. It is quite clear and can be accepted in the present form.
Just some format aspects need to be fixed:

• Spaces between values and units (sometimes present sometimes not);
• Capital letters in the middle of a sentence (line 271);
• Double references numbering (1. [1]).

Author Response

The submitted manuscript presents a review on the single and multi-nozzle atomization in spray drying. It is quite clear and can be accepted in the present form.
Just some format aspects need to be fixed:

• Spaces between values and units (sometimes present sometimes not);
• Capital letters in the middle of a sentence (line 271);
• Double references numbering (1. [1]).

Thank you for your comments to improve the paper. We made all corrections that you suggested