Applied sciences

Chemical and Process Engineering


Chemical and Process Engineering | 2021 | vol. 42 | No 2 |

Authors and Affiliations

Eugeniusz Molga

  1. Faculty of Chemical and Process Engineering, Warsaw University of Technology

Authors and Affiliations

Ryszard Pohorecki

  1. Warsaw University of Technology, Faculty of Chemical and Process Engineering, ul. Warynskiego 1, 00-645 Warsaw, Poland
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Flow patterns generated by two ChemShear impellers, CS2 and CS4 have been measured and flow numbers calculated; Fl = 0.04 for both impellers. Transient and equilibrium drop sizes, d32 μm. of 3 different viscosity silicone oils agitated by a high-shear Rushton turbine, RT, a low-shear, high-flow HE3 impeller and the two ChemShears were determined. The equilibrium d32 are correlated by d_32=1300〖(ε_T)〗_(^(-0.58) v^0.14 with an R2 = 0.94. However, the time to reach steady state and the equilibrium size at the same specific power do not match the above descriptors of each impeller’s characteristics. In other literature, these descriptors are also misleading. In the case of mixing time, a high shear RT of the same size as a high flow HE3 requires the same time at the same specific power in vessels of H/T = 1. In bioprocessing, where concern for damage to cells is always present, free suspension animal cell culture with high shear RTs and low-shear impellers is equally effective; and with mycelial fermentations, damage to mycelia is greater with low shear than high. The problems with these descriptors have been known for some time but mixer manufacturers and ill-informed users and researchers continue to employ them.

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Authors and Affiliations

Andrzej W. Pacek
Alvin W. Nienow

  1. School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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In-line rotor-stators are widely used for power intensive industrial applications, such as deagglomeration, emulsification. There is limited information on characteristic power numbers for different designs which can be used to calculate the average power input as a means to evaluate process performance. This study made use of 18 different rotor-stators, 17 of which were toothed designs with different geometry, and also a commercially available design, with the objectives of evaluating the applicability of different expressions for characteristic power numbers and establishing the effects of geometric variations on the power input.

The expression P=〖Po〗_1 ρN^3 D^5+〖Po〗_2 ρN^2 D^2 Q is found to account for the experimental data over a wide range of operating conditions.

Rotor diameter was found to have the most prominent effect on the power input: an increase in rotor diameter from 119.6 to 123.34 mm resulted in an increase in the average power draw. The effect of rotor diameter examined with geometrically similar set ups reducing the diameter from 123.34 to 61.44 mm, for which the mixing chamber was also proportionately smaller, showed a decrease in the power input at a given speed and flowrate as well. The effects relating to the percentage of open area of the stator and number of rotor teeth were less obvious. Increasing the open area resulted in an increase in the power input – an effect which could be observed more clearly as the flowrate (1 to 4 l/s) and rotor speed (at 2000 and 3000 rpm) were also increased. Increasing the number of stator teeth increased the power input and this effect was more prominent when operating at the highest rotor speed of 3000 rpm and at low flowrates (1–2 l/s).
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Authors and Affiliations

Alex Hannam
Trevor Sparks
N. Gül Özcan-Taskın

  1. Loughborough University, School of Chemical Engineering, Loughborough LE11 3TT, UK
  2. Independent Consultant
  3. Loughborough University, School of Chemical Engineering, Loughborough LE11 3TT, UK 2
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Modelling of titanium dioxide deagglomeration in the mixing tank equipped with a high shear impeller is presented in this study. A combination of computational fluid dynamics with population balance was applied for prediction of the final particle size. Two approaches are presented to solve population balance equations. In the first one, a complete population balance breakage kinetics were implemented in the CFD code to simulate size changes in every numerical cell in the computational domain. The second approach uses flow field and properties of turbulence to construct a mechanistic model of suspension flow in the system. Such approach can be considered as an attractive alternative to CFD simulations, because it allows to greatly reduce time required to obtain the results, i.e., the final particle size distribution of the product. Based on experiments shattering breakage mechanism was identified. A comparison of the mechanistic model and full CFD does not deviate from each other. Therefore the application of a much faster mechanistic model has comparable accuracy with full CFD. The model of particle deagglomeration does not predict a very fast initial drop of particle size, observed in the experiment, but it can predict, with acceptable accuracy, the final particle size of the product.
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Authors and Affiliations

Radosław Krzosa
Krzysztof Wojtas
Jakub Golec
Łukasz Makowski
Wojciech Orciuch
Radosław Adamek

  1. Warsaw University of Technology, Faculty of Chemical and Process Engineering, ul.Warynskiego 1, 00-645 Warsaw, Poland
  2. ICHEMAD–Profarb, ul. Chorzowska 117, 44–100 Gliwice, Poland
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The non-stationary problem of temperature distribution in a circular cylindrical channel of infinite length filled with a homogeneous biomass material moving with a constant velocity in the axial direction was investigated. The heat source was a shaftless helical screw (or auger), which was heated with an electric current due to the Joule–Lenz effect and rotated uniformly around the axis of symmetry of the channel. Similar problems arise in the thermal processing of biomaterials using screw conveyor in pyrolysis and mass sterilization and pasteurization of food products. The problem is solved using the expansion of given and required functions in Fourier series over angular coordinate and integral Fourier and Laplace transforms over axial coordinate and time, respectively. As a result, the temperature field is obtained as the sum of two components, one of which, global, is proportional to time, and the other, which forms the microstructure of the temperature profile, is given by Fourier–Bessel series. The coefficients of the series are determined by the integrals calculated using the Romberg method. Based on the numerical calculations, the analysis of the space-time microstructure of the temperature field in the canal was performed. A significant dependence of the features of this microstructure on the geometric, kinematic and thermodynamic characteristics of the filling biomass and the screw was revealed.
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Authors and Affiliations

Stanisław Ledakowicz
Olexa Piddubniak

  1. Faculty of Process and Environmental Engineering, Lodz University of Technology, Wolczanska St. 215, 90-924 Lodz, Poland
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Efficiency of agitation was considered for different physical systems on the basis of our own experimental studies on homogenisation, heat and mass transfer as well as gas hold-up. Measurements were performed for different physical systems: Newtonian liquids of low and higher viscosity, pseudoplastic liquid, gas–liquid and gas–solid–liquid systems agitated in vessels of the working volume from 0.02 m3 to 0.2 m3. Agitated vessels of different design were equipped with a high-speed impeller (10 impellers were tested). Comparative analysis of the experimental results proved that energy inputs (power consumption) should be taken into account as a very important factor when agitation efficiency is evaluated in order to select a proper type of equipment. When this factor is neglected in the analysis, intensification of the process can be estimated only.
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Authors and Affiliations

Joanna Karcz
Jolanta Szoplik
Marta Major-Godlewska
Magdalena Cudak
Anna Kiełbus-Rapała

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, al. Piastów 42, 71-065 Szczecin, Poland
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We demonstrate in this study that a rotating magnetic field (RMF) and spinning magnetic particles using this kind of magnetic field give rise to a motion mechanism capable of triggering mixing effect in liquids. In this experimental work two mixing mechanisms were used, magnetohydrodynamics due to the Lorentz force and mixing due to magnetic particles under the action of RMF, acted upon by the Kelvin force. To evidence these mechanisms,we report mixing time measured during the neutralization process (weak acid-strong base) under the action of RMF with and without magnetic particles. The efficiency of the mixing process was enhanced by a maximum of 6.5% and 12.8% owing to the application of RMF and the synergistic effect of magnetic field and magnetic particles, respectively.
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Authors and Affiliations

Rafał Rakoczy
Marian Kordas
Agata Markowska-Szczupak
Maciej Konopacki
Adrian Augustyniak
Joanna Jabłońska
Oliwia Paszkiewicz
Kamila Dubrowska
Grzegorz Story
Anna Story
Katarzyna Ziętarska
Dawid Sołoducha
Tomasz Borowski
Marta Roszak
Bartłomiej Grygorcewicz
Barbara Dołęgowska

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42,71-065 Szczecin, Poland
  2. Pomeranian Medical University in Szczecin, Chair of Microbiology, Immunology and Laboratory Medicine, Department of Laboratory Medicine, al. Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland
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Complex rheological properties of yield-stress materials may lead to the generation of an intensive mixing zone near a rotating impeller. From the practical point of view, the zone should cover most of the stirred liquid. According to the literature review, several parameters may affect the size of the mixing zone, in particular forces exerted on the liquid. This paper presents both experimental and numerical investigation of axial and tangential forces generated during mechanical mixing of yield-stress fluids in a stirred tank. The tested fluids were aqueous solutions of Carbopol Ultrez 30 of concentration either 0.2 or 0.6 wt% and pH = 5:0. The study was performed for three types of impeller, pitched blade turbine, Prochem Maxflo T and Rushton turbine, in a broad range of their rotational speed, N = 60 - 900 rpm. The axial and tangential forces were calculated from the apparent mass of the stirred tank and torque, respectively. The experimental results were compared with CFD predictions, revealing their good agreement. Analysis of the generated forces showed that they are dependent on the rheological characteristic of liquid and the impeller type. It was also found that although axial force was smaller than tangential force, it significantly increased the resultant force.
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Authors and Affiliations

Anna Story
Grzegorz Story
Zdzisław Jaworski

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42,71-065 Szczecin, Poland

Instructions for authors

All manuscripts submitted for publication in Chemical and Process Engineering must comprise a description of original research that has neither been published nor submitted for publication elsewhere.

The content, aim and scope of the proposals have to comply with the main topics of the journal, i.e. discuss at least one of the four main areas, namely:
• New Advanced (Nano) Materials
• Environment & Water Processing (including circular economy)
• Biochemical & Biomedical Engineering (including pharmaceuticals)
• Climate & Energy (including energy conversion & storage, electrification, decarbonization)

Chemical and Process Engineering publishes: i) experimental and theoretical research papers, ii) short communications, iii) critical reviews, and iv) perspective articles. Each publication form is peer-reviewed by at least two independent referees.

New Submissions

Manuscripts are submitted for publication via Editorial System. When writing a manuscript, you may choose to submit it as a single Word file to be used in the refereeing process. The manuscript needs to be written in a clear way. The minimum requirements are:
• Please use clear fonts, at least 12 points large, with at least 1.5-line spacing.
• Figures should be placed in relevant places within the manuscript. All figures and tables should be numbered and provided with appropriate caption and legend, if necessary.

Language requirements

• Use Simple Past to talk about your experiment and your results as they were finished before you wrote the paper. Use Simple Past to describe what you did.
Example: Two samples were taken. Temperature increased to 200K at the end of the process.
• Use Simple Present to refer to figures and tables.
Example: Table 2 shows nitrogen concentration changes in the process.
• Use Simple Present to talk about your conclusions. You move here from describing your results to stating what is generally true.
Example: The process is caused by changes of nitrogen concentration.
• Capitalise words like ‘Table 2’, ‘Equation 11’.
• If a sentence is longer than three lines, break down your writing into logically divided parts (paragraphs). Start a new paragraph to discuss a new concept.
• Check noun/verb agreement (singular/plural).
• It is fine to choose either British or American English but you should avoid mixing the two.
• Avoid empty language (it is worth pointing out that, etc.).

Revised Submission

After the first revision, authors will be requested to put their paper in the correct format, using the below guidelines and template for articles.

Manuscript outline

1. Header details
a. Title,
b. Names (first name and further initials) and surnames of authors,
c. Institution(s) (affiliation),
d. Address(es) of authors,
e. ORCID number of all authors.
f. Information about the corresponding author: name and surname, email address.

2. Abstract – should contain a short summary of the proposed paper. In the maximum of 200 words the authors should present the main assumptions, results and conclusions drawn from the presented study.

3. Keywords – up to 5 characteristic keyword items should be provided.

4. Text
a. Introduction. In this part, the rationale for research and formulation of the scientific problem should be included and supported by a concise review of recent literature.
b. Main text. It should contain all important elements of the scientific investigations, such as presentation of experimental setup, mathematical models, results and their discussion. This part may be divided into the following sections: Methods, Results, Discussion.
c. Conclusions. The major conclusions can be put forward in a concise style in a separate chapter. A presentation of conclusions from the reported research work accompanied by a short commentary is also acceptable.
d. Figures: drawings, diagrams and photographs can be in colour and should be located in appropriate places in the manuscript. Their form should be of a vector or raster type with the minimum resolution of 900 dpi. In addition, all figures, including drawings, graphs and photos should be uploaded in a separate file via Editorial System in one of the following formats: bmp, tiff, jpg or eps. For editorial reasons, graphic elements created with MS Word or Excel will not be accepted. They should be saved as image files in the source program. Screen shots will not be accepted. The basic font size of letters used in figures should be at least 10 pts after adjusting graphs to the final size.
e. Tables should be made according to the format shown in the template.
f. All figures and tables should be numbered and provided with an appropriate caption and legend, if necessary. They have to be properly referenced to and commented in the text of the manuscript.

5. List of symbols should be accompanied by their units

6. Acknowledgements may be included before the list of literature references

7. Literature citations
The method of quoting literature source in the manuscript depends on the number of its authors:
single author – their surname and year of publication should be given, e.g. Marquardt (1996) or (Marquardt, 1996),
two authors – the two surnames separated by the conjunction “and” with the publication year should be given, e.g. Charpentier and McKenna (2004) or (Charpentier and McKenna, 2004),
three and more authors – the surname of the first author followed by the abbreviation “et al.” and year of publication should be given, e.g. Bird et al. (1960) or (Bird et al., 1960).

In the case of citing more sources in one bracket, they should be listed in alphabetical order using semicolon for separation, e.g. (Bird et al., 1960; Charpentier and McKenna, 2004; Marquardt, 1996). Should more citations of the same author(s) and year appear in the manuscript then letters “a, b, c, ...” should be successively applied after the publication year.

Bibliographic data of the quoted literature should be arranged at the end of the manuscript in alphabetical order of surnames of the first author. It is obligatory to indicate the DOI number of those literature items, whose numbers have already been assigned. Journal titles should be specified by typing their right abbreviations or, when in doubts, according to the Science and Engineering Journal Abbreviations.

Examples of citation for:

Charpentier J. C., McKenna T. F., 2004. Managing complex systems: some trends for the future of chemical and process engineering. Chem. Eng. Sci., 59, 1617-1640. DOI: 10.1016/j.ces.2004.01.044.
Information from books (we suggest adding the page numbers where the quoted information can be found)
Bird R. B., Stewart W.E., Lightfood E.N., 2002. Transport Phenomena. 2nd edition, Wiley, New York, 415-421.
Chapters in books
Hanjalić K., Jakirlić S., 2002. Second-moment turbulence closure modelling, In: Launder B.E., Sandham N.D. (Eds.), Closure strategies for turbulent and transitional flows. Cambridge University Press, Cambridge, 47-101.
ten Cate A., Bermingham S.K., Derksen J.J., Kramer H.M.J., 2000. Compartmental modeling of an 1100L DTB crystallizer based on Large Eddy flow simulation. 10th European Conference on Mixing. Delft, the Netherlands, 2-5 July 2000, 255-264.

Cover letter

Authors are kindly asked to provide a cover letter which signifies the novelty and most important findings of the manuscript as well as the significance to the field.

Author contributions

During submission, authors will be asked to provide the individual contributions to the paper using the relevant CRediT roles: Conceptualization; Data curation; Formal analysis; Funding acquisition; Investigation; Methodology; Project administration; Resources; Software; Supervision; Validation; Visualization; Roles/Writing - original draft; Writing - review & editing.

Suggested Reviewers

Authors are kindly requested to include a list of 4 potential reviewers for their manuscript, with complete contact information. Suggested reviewers may not reside in the same country as the corresponding author and remain subject to the Editors' discretion in appointing manuscripts for review.


Starting from 2014 a principle of publishing articles against payment is introduced, assuming non-profit making editorial office. According to the principle, authors or institutions will have to cover the expenses amounting to 10 € per published page. The above amount will be used to supplement the limited financial means received from the Polish Academy of Sciences for the editorial and publishing expenses. The method of payment will be indicated in an invoice sent to the authors or institutions after acceptance of their manuscripts to be published.

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Editors of the "Chemical and Process Engineering" pay attention to maintain ethical standards in scientific publications and undertake any possible measure to counteract neglecting the standards. Papers submitted for publication are evaluated with respect to reliability, conforming to ethical standards and the advancement of science. Principles given below are based on COPE's Best Practice Guidelines for Journal Editors, which may be found at:

Authors’ duties

Authorship should be limited to persons, who markedly contributed to the idea, project, realization and interpretation of results. All of them have to be listed as co-authors. Other persons, who affected some important parts of the study should be listed or mentioned as co-workers. Author should be certain that all co-authors were enlisted, saw and accepted final version of the paper and agreed upon its publication.

Disclosure and conflict of interests
Author should disclose all sources of financing of his/her study, the input of scientific institutions, associations and other subjects and all important conflicts of interests that might affect results and interpretation of the study.

Standards in reporting
Authors of papers based on original studies should present precise description of performed work and objective discussion on its importance. Source data should be accurately presented in the paper. The paper should contain detailed information and references that would enable others to use it. False or intentionally not true declarations are not ethical and are not accepted by the editors.

Access to and storage of data
Authors may be asked for providing raw data used in the paper for editorial assessment and should be prepared to store them within the reasonable time period after publication.

Multiple, unnecessary and competitive publications
As a rule author should not publish papers describing the same studies in more than one journal or primary publication. Submission of the same paper to more than one journal at the same time is not ethical and prohibited.

Confirmation of sources
Author should cite papers that affected the creation of submitted manuscript and every time he/she should confirm the use of other authors’ work.

Important errors in published papers
When author finds an important error or inaccuracy in his/her paper, he/she is obliged to inform Editorial Office about this as soon as possible.

Originality and plagiarism
Author may submit only original papers. He/she should be certain that the names of authors referred to in the paper and/or fragments of their texts are properly cited or mentioned.

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Duties of the Editorial Office

Editors’ duties
Editors know the rules of journal editing including the procedures applied in case of uncovering non-ethical practices.

Decisions on publication
Editor-in Chief is obliged to apply present legal status as to defamation, violation of author’s rights and plagiarism and bears the responsibility for decisions. He/she may consult thematic editors and/or referees in that matter.

Selection of referees
Editorial Office provides appropriate selection of referees and takes care about appropriate course of peer –reviewing (the review has to be substantive).

Every member of editorial team is not allowed to disclose information about submitted paper to any person except its author, referees, other advisors and editors.

To counteract discrimination the Editorial Office obeys the legally binding rules.

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Not published papers or their fragments cannot be used in the studies of editorial team or ref-erees without written consent of the author.

Referees' duties

Editorial decisions

Referee supports Editor-in-Chief in taking editorial decisions and may also support author in improving the paper.

Back information
In case a selected referee is not able to review the paper or cannot do it in due time period, he/she should inform secretary of the Editorial Office about this fact.

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All reviews should be made anonymously and the Editorial Office does not disclose names of the authors to referees.

Disclosure and conflict of interests
Confidential information or ideas resulting from reviewing procedure should be kept secret and should not be used to gain personal benefits. Referees should not review papers, which might generate conflict of interests resulting from relationships with the author, firm or institution involved in the study.

Confirmation of sources
Referees should indicate publications which are not referred to in the paper. Any statement that the observation, source or argument was described previously should be supported by appropriate citation. Referee should also inform the secretary of the Editorial Office about significant similarity to or partial overlapping of the reviewed paper with any other published paper and about suspected plagiarism.

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