Performance evaluation of a novel pilot-scale pinned disc rotating generator of hydrodynamic cavitation

Gostiša, Jurij (author), Širok, Brane (author), Kolbl Repinc, Sabina (author), Levstek, Marjetka (author), Stražar, Marjetka (author), Bizjan, Benjamin (author), Zupanc, Mojca (author)

This study investigates hydrodynamic performance of a novel pinned disc rotating generator of hydrodynamic cavitation in comparison with a serrated disc variant on a pilot-scale. Experimental results show that at a given rotational speed and liquid flow rate, the pinned disc generates more intense cavitation (i.e. lower cavitation number, higher volume fraction of vapor and higher amplitude of pressure fluctuations) than the serrated disc, while also consuming less energy per liquid pass (i.e., higher flow rate and pumping pressure difference of water at similar power consumption). Additionally, mechanical and chemical wastewater treatment performance of the novel cavitator was evaluated on an 800 L influent sample from a wastewater treatment plant. Mechanical effects resulted in a reduction of average particle size from 148 to 38 µm and increase of specific surface area, while the oxidation potential was confirmed by reduction of COD, TOC, and BOD up to 27, 23 and 30% in 60 cavitation passes, respectively. At optimal operating conditions and 30 cavitation passes, pinned disc cavitator had a 310% higher COD removal capacity while consuming 65% less energy per kg of COD removed than the serrated disc cavitator. Furthermore, the specific COD-reduction energy consumption of the pinned disc cavitator on the pilot scale is comparable to the best cases of lab-scale orifice and venturi devices operating at much lower wastewater processing capacity.

• Language: English
• Keywords: hydrodynamic cavitation, pinned disc, serrated disc, performance evaluation, wastewater
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering; FGG - Faculty of Civil and Geodetic Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 13 str.
• Numbering: Vol. 72, art. 105431
• PID: 20.500.12556/RUL-126452
• UDC: 532:62(045)
• ISSN on article: 1350-4177
• DOI: 10.1016/j.ultsonch.2020.105431
• COBISS.SI-ID: 44977667
• Publication date in RUL: 22.04.2021

Record is a part of a journal

• Title: Ultrasonics Sonochemistry
• Shortened title: Ultrason. sonochem.
• Publisher: Butterworth-Heinemann, Elsevier Science
• ISSN: 1350-4177
• COBISS.SI-ID: 707668

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: tehnika, strojništvo, hidrodinamika, odpadne vode, hidrodinamska kavitacija, mimobežni valjčki, mimobežni zobje, ocena učinkovitosti