Investigation into cavitational intensity and COD reduction performance of the pinned disc reactor with various rotor-stator arrangements

Abstract

Graphical abstract

RETRACTED: Hydrodynamic Cavitation: A Novel Non-Thermal Liquid Food Processing Technology

“…Advanced rotational HCRs (ARHCRs) that appeared recently (Figure 1C), where cavitation is induced by a high-speed rotating rotor, have demonstrated more superior performance in many applications, especially in food processing (1,15), compared with conventional devices. Several researchers have been devoted to demonstrating their mechanisms by experimental [flow visualization (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29) and vibration (20,21,26,27) and thermal characteristics (19,23,28)] and numerical methods (30,31). Nevertheless, the research on this emerging type of device is relatively limited even though it has been commercialized nowadays.…”

Computational analysis of flow conditions in hydrodynamic cavitation generator for water treatment processes

“…Based on the qualitative cavitation cloud dynamics comparison, similarities to the calculated results can be observed. Cavitation cloud dynamics was experimentally evaluated as shown in the work by Gostiša et al [ 10 ] The image was first rotated around the disc centre of rotation, and the cloud area was extracted from the image with an algorithm that includes mean background subtraction, pin masking, greyscale thresholding, and morphological closing. The overall trend of vapour fraction was found to be higher in the cases of 0.25 gap, 8 pin, and 12 pin compared to lower vapour fractions in the other two cases.…”

“…Based on the experimental observations on a pilot‐scale device [ 10 ] we focused our numerical study on the investigation of the dynamics of the interaction between the rotor and the stator (the gap between them) and the interaction among the rotor pins (the spacing between them)—the goal was to determine the details of the influences of the beforementioned parameters on the development of the cavitation cloud and the conditions in the cavitating zone. Since the focus of the interaction covers only a very small part of the device, a simplified 2D geometry was used for the simulations.…”

“…This type of device was initially investigated on a pilot scale by Gostiša et al [ 9 , 10 ] where mechanisms of cavitation generation were experimentally determined by high‐speed visualization and pressure fluctuation measurements. Principally, cavitation was found to occur behind the element, presumably in the low‐pressure wake behind, and fluctuating vapour cloud dynamics was attributed to the passing rotor‐stator interaction.…”

“…We can generally divide them into (i) pumping and constriction reactors, [ 3 , 4 ] (ii) blow‐through reactors, [ 5 , 6 ] and (iii) rotor‐stator reactors. [ 7 , 8 , 9 , 10 ] Most of the advanced laboratory‐scale reactors are of the pump and constriction type, where the contaminated water (containing bacteria, viruses, algae, etc.) is forced by the pump through an orifice or venturi constriction where the sample cavitates.…”