Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this manuscript, Paas et al have developed a cross- flow separation technique for the separation of suspensions. It enables the classification of the particles according to their size, as well as allows their separation based on the electrophoretic mobility. They have utilized a combination of experimental and simulation techniques to investigate the particle in motion. 

 

 

Major Comments:

 

1) In this manuscript, the authors have not mentioned the materials and methods utilized for determining particle size and electrophoretic mobility. The materials and methods should be explicitly mentioned.

 

2) The authors need to clearly discuss the importance of the three setups that have been discussed in this manuscript.

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Particle separation has been critical for purification of ceramics, polymer, cell, and other are. Cross flow with the application of electronic field is one of most important technique. Based on the previous theory, manuscript has much information, and contains interesting topic. however, some are uncertain, as mentioned below,

1) In abstract, quantitative information is required, range of flow rate, size of particle, and species...

2) Hydrodynamic interaction is critical and now hard to understand. please mention in the section of theory.

3) in Theory section, Reynolds number is set at less than 1. how is your experimental situation?

4) I understand the CFD calculation  and the meaning of the obtained results. Can you show the effect of concentration and limitation of flow rate, based on your speculation. I guess they will be future research.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript delivers a well-rounded investigation of a novel multidimensional separation process that combines hydrodynamic and electrophoretic forces. The integration of experimental studies, CFD simulations, and optical visualization provides a comprehensive understanding of particle behavior and process optimization. The paper stands out for its detailed description of experimental setups, thoughtful scale-up approaches, and the use of high-resolution imaging for particle tracking. The theoretical foundation is robust, and the study’s industrial relevance is evident, particularly in the context of fine particle separation in the micron range.  While the paper is strong, several specific aspects need further refinement or clarification:  

1. In introduction, line 48. Provide a specific example or application where "multidimensional separation" has been successfully utilized to contextualize its relevance.  

2. In the section "3.1. Experimental setups", the justification for choosing a single gap and three-gap profiles needs elaboration. Include a brief discussion on why these geometries were selected over others. Also check the row "gap distance" in the table 1.

3. Page 10, Line 302. The resolution of 2 µm/pixel for particle tracking is mentioned, but the impact of this resolution on particle size measurement accuracy should be quantified.  

4. In the section "3.3. Particle system". The particle size distribution (PSD) of soda-lime beads should be supplemented with error bars or standard deviations for better statistical representation. 

5. Lines 582-590. Expand on the mitigation strategies for bubble formation due to electrolysis and discuss how this phenomenon could influence long-term operational stability.  

6. In thee section "3.2 Investigation on continuous separation with scale-up approaches". For the scale-up approach using three-gap geometry, provide numerical evidence or a comparison table showing efficiency improvements over the single-gap setup.  

In conclusion, the manuscript is a well-executed study on multidimensional separation processes, with significant implications for fine particle separation technologies. Addressing the detailed comments above would strengthen the manuscript’s clarity and rigor while enhancing its applicability to real-world scenarios. This study offers valuable insights and provides a solid foundation for future research in particle separation methods.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf