Cavitation Treatment Research Articles

Acoustic black hole immersed sonoreactor for high-efficiency cavitation treatment

Developing innovative sonoreactors to enhance acoustic processing efficiency holds immense importance in the field of sonochemistry. Traditional immersed sonoreactors (TISs) mainly produce cavitation at the probe tip, with a relatively weak cavitation around the probe, resulting in posing challenges for high-efficiency cavitation treatment. Here we propose an acoustic black hole immersed sonoreactor (ABHIS) in longitudinal-flexural coupled vibration, enabling high-efficiency cavitation treatment by unleashing the cavitation potential of the probe. The symmetrical structure of the probe is altered to introduce a coupling of flexural vibration mode, and an acoustic black hole (ABH) profile is integrated to further enhance both flexural wave number and amplitude. In this paper, we present a systematic theoretical design method for ABHIS and compare its performance with TIS using finite element method (FEM). An ABHIS prototype is fabricated and subjected to experimental tests and cavitation observation. The results demonstrate that our theoretical analysis model accurately predicts the frequency characteristics of ABHIS. The proposed ABHIS exhibits satisfactory dynamic characteristics, with significantly increased vibration displacement and acoustic radiation ability compared to TIS. Importantly, the ABH design significantly expands ultrasonic cavitation regions and enhances acoustic radiation intensity of ABHIS resulting in a substantial improvement in acoustic processing efficiency.

Degradation of Congo Red Using Periodate, Activated by Ultrasound and Iron(II)

The periodate, activated by the combination of ultrasound and Fe(II), was used for oxidative degradation of an anionic diazo dye of congo red (CR). The effect of the main factors (the initial pH, the molar ratio of CR:KIO4:FeSO4, the amount of Fe(II), and the specific power of ultrasonic cavitation treatment) on its degradation efficiency was analyzed.

Effect of ultrasonic-hydraulic coupling cavitation pretreatment on carbon extraction from coal gasification coarse slag by flotation

Coal gasification coarse slag represents a type of low-value solid waste produced in coal gasification. This study investigated how the pretreatment of the pulp obtained from coal gasification coarse slag affects carbon extraction by flotation. Ultrasonic treatment can promote carbon ash separation. Flotation results revealed that at an ultrasonic action time of 15 min, the ultrasonic power was 90 W and the microbubble generator flow rate was 300 ml/min. Moreover, the best flotation effect was observed under these conditions. Compared with the results obtained for conventional flotation, the concentrate ash content decreased from 36.88 % to 25.51 % and the combustible substance recovery index increased from 79.84 % to 92.91 %. After coupled cavitation treatment, coal gasification coarse slag exhibited a reduced particle size, an increased specific surface area, a smooth and clean surface, a reduced number of surface inorganic elements, an increased number of pores and a remarkable carbon ash separation effect. This study can provide a reference for special methods such as ultrasonic-hydraulic coupling cavitation to strengthen the flotation of coal gasification coarse slag.

Mechanical Damage to Coal and Increased Coal Permeability Caused by Water-Based Ultrasonic Cavitation

Coalbed methane (CBM), recognized as a sustainable and environmentally friendly energy source, plays a crucial role in mitigating global climate change and advancing low-carbon energy solutions. However, the prevalence of low-permeability coal seams poses a significant challenge to effective CBM extraction. Improving coal permeability has emerged as a viable strategy to address the issue of low-permeability coal. Conventional CBM stimulation methods fall short in overcoming this obstacle. In contrast, the enhanced technique of CBM extraction by water-based ultrasonic cavitation holds great promise due to its use of high energy intensity, safety, and efficiency. Nevertheless, the inadequate theoretical framework for managing this technology impedes its widespread adoption for large-scale applications. This study investigated the impact of water-based ultrasonic cavitation treatment on coal’s properties and permeability through mechanical testing and permeability measurements conducted before and after treatment. This study also explored the process by which this technology, known as WUC-ECBM, improves coal’s mechanical properties and permeability. The findings suggest a potential stimulation technique (WUC-ECBM) for use in CBM extraction, and its physical mechanism.

Chronic adenoiditis and its effect on the reactivity of the bronchopulmonary system, the possibility of non-drug correction

Introduction. In pediatric otorhinolaryngological practice, chronic adenoiditis is one of the most common diseases and causes the search for additional and effective methods of treatment.Aim. To evaluate the clinical effectiveness of the use of aqueous solutions treated with low-frequency ultrasound with high specific energy and monochromatic light radiation in the complex therapy of chronic adenoiditis in children.Materials and methods. The number of participants in the study was 104 patients aged 4 to 15 years with a verified diagnosis of chronic adenoiditis and were divided into 3 groups depending on the treatment. A comparative analysis of the results obtained was carried out before the start of therapy (day 0) and on the 7th day after the treatment. The state of the nasopharynx was assessed using a flexible nasopharyngoscope, as well as the structure of the middle ear and auditory tube during acoustic impedancemetry.Results. The use of a course of treatment of low-frequency ultrasonic cavitation in combination with photochromotherapy made it possible to relieve the signs of chronic adenoiditis in 62% of cases (p < 0.001), reduce the number of patients with grade III adenoid hypertrophy by 54% (p = 0.035), and reduce by 2 times (p = 0.05) number of relapses of chronic adenoiditis. In the group of children using low-frequency ultrasonic cavitation, the positive effect of treatment was 3.3 times [CI 0.75; 14.6] higher compared to the control group, and in combination with photochromotherapy it was 3.6 times [CI 0.85; 15.5]. The absence of adenotomy was assessed as a positive effect.Conclusion. The data obtained showed that the inclusion of non-drug methods of physical influence (low-frequency ultrasonic cavitation both in monotherapy and in combination with photochromotherapy) in complex treatment can reduce the number of surgical interventions on the organs of the lymphopharyngeal ring – the pharyngeal tonsil.

MOC-Z Model of Transient Cavitating Flow in Viscoelastic Pipe

In this paper, a unitary method for the solution of transient cavitating flow in viscoelastic pipes is proposed in the framework of the method of characteristics (MOC) and a Z-mirror numerical scheme (MOC-Z model). Assuming a standard form of the continuity equation allows the unified treatment of both viscoelasticity and cavitation. An extension of the MOC-Z is used for Courant numbers less than 1 to overcome a few cases with numerical instabilities. Four viscoelastic models were considered: a Kelvin–Voigt (KV) model without the instantaneous strain, and three generalised Kelvin–Voigt models with one, two, and three KV elements (GKV1, GKV2, and GKV3, respectively). The use of viscoelastic parameters of KV and GKV models calibrated for transient flow tests without cavitation allows good comparisons between experimental and numerical pressure versus time for transient tests with cavitation. Whereas for tests without cavitation, the mean absolute error (MAE) always decreases when the complexity of the model increases (from KV to GKV1, GKV2, and GKV3) for all the considered tests, this does not happen for tests with cavitation, probably because the decreasing capacity of parameter generalization for the increasing complexity of the model. In particular, in the examined cases, the KV model performs better than the GKV1 and the GKV3 models in three cases out of five, and the GKV2 model performs better than the GKV3 model in three cases out of five. Furthermore, the GKV2 model performs better than the KV model only in three cases out of five.

ASESSMENT OF THE EFFECTIVENESS OF CAVITATION PROCESSING OF DARK OIL PRODUCTS

The paper presents experimental results of the influence of the conditions of cavitation treatment of dark petroleum products in the hydrodynamic regime on the yield of fractions boiling up to 400 °C. Straight-run products (fuel oils, vacuum gas oils), as well as catalytic cracking gas oils, were considered as raw materials. The influence of raw material characteristics (density, fractional and group hydrocarbon composition) and its processing conditions (pressure, at five cycles of exposure) on the yield of the target fraction is considered. The linear dependence of the yield of the target fractions on the processing pressure is revealed. The constructed regression models are adequate, informative, and all their coefficients are significant. Taking into account the density of the feedstock did not improved models. The best model constructed was tested using the cross-validation method. The average forecast error was 11%, the maximum was 22%. For a small number of samples, such an error is acceptable. The possibility of assessing the effectiveness of cavitation treatment of crude oil based on data on its fractional and group hydrocarbon composition is shown. It was possible to build several regression models linking the increase in yield with pressure during processing and the content of resins and oils in the raw materials. All of them are adequate and informative, and their coefficients are significant. The increase in the yield of fractions boiling up to 400 °C is associated with the transformations of hydrocarbons during cavitation. The possibility of evaluating the effectiveness of cavitation treatment of petroleum raw materials based on data on its group hydrocarbon composition has been established. Several regression models have been constructed linking the increase in yield with the pressure during processing and the content of resins and oils in the raw materials. All of them are adequate and informative, and their coefficients are significant. Based on the constructed models, it is assumed that the change in the fractional composition of petroleum products during cavitation treatment is more associated with the destruction of the transition and solvate layers of complex structural units of the oil dispersed system than with the course of cracking reactions. For citation: Peshnev B.V., Burlyaeva E.V., Nikishin D.V., Nikolaev A.I., Kuznetsov A.S. Asessment of the effectiveness of cavitation processing of dark oil products. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 7. P. 103-110. DOI: 10.6060/ivkkt.20246707.7006.

Employing machine learning for enhanced abdominal fat prediction in cavitation post-treatment

This study investigates the application of cavitation in non-invasive abdominal fat reduction and body contouring, a topic of considerable interest in the medical and aesthetic fields. We explore the potential of cavitation to alter abdominal fat composition and delve into the optimization of fat prediction models using advanced hyperparameter optimization techniques, Hyperopt and Optuna. Our objective is to enhance the predictive accuracy of abdominal fat dynamics post-cavitation treatment. Employing a robust dataset with abdominal fat measurements and cavitation treatment parameters, we evaluate the efficacy of our approach through regression analysis. The performance of Hyperopt and Optuna regression models is assessed using metrics such as mean squared error, mean absolute error, and R-squared score. Our results reveal that both models exhibit strong predictive capabilities, with R-squared scores reaching 94.12% and 94.11% for post-treatment visceral fat, and 71.15% and 70.48% for post-treatment subcutaneous fat predictions, respectively. Additionally, we investigate feature selection techniques to pinpoint critical predictors within the fat prediction models. Techniques including F-value selection, mutual information, recursive feature elimination with logistic regression and random forests, variance thresholding, and feature importance evaluation are utilized. The analysis identifies key features such as BMI, waist circumference, and pretreatment fat levels as significant predictors of post-treatment fat outcomes. Our findings underscore the effectiveness of hyperparameter optimization in refining fat prediction models and offer valuable insights for the advancement of non-invasive fat reduction methods. This research holds important implications for both the scientific community and clinical practitioners, paving the way for improved treatment strategies in the realm of body contouring.

Ultrasonic cavitation strengthening and generation of superhydrophobicity for the surface of in situ (ZrB2 + Al2O3)/AA6016 matrix composite

To enhance the operating stability and durability of the aluminum matrix composite, the superhydrophobic surface is constructed on the substrate of in situ ZrB2 and Al2O3 nano-particle reinforced AA6016 matrix composite. The method incorporating ultrasonic cavitation treatment and low surface energy modification is applied. The performance of the obtained superhydrophobic surface is investigated through comprehensively analyzing micro and nano surface structures, roughness, water contact angle, chemical composition, and mechanical property. The results indicate that the water contact angle and water sliding angle of the specimen treated with cavitation for 9 min and then modified with fluorosilane attain 163.8° and 7.3°, respectively. High superhydrophobicity is accomplished. Long exposure to ultrasonic cavitation treatment results in the shift from hydrophobicity to hydrophilicity. The presence of particle-reinforced phases induces a pinning effect, causing the accumulation and entanglement of dislocations beneath the surface. This phenomenon leads to a 64.7 % increase in surface hardness, and the thickness of the work hardening layer reaches about 300 μm. The obtained conclusions shed light on the preparation of superhydrophobic surface for the aluminum matrix composite, and the application of aluminum matrix composites in harsh environment is expected to be broadened.

The changes induced by hydrodynamic cavitation treatment in wheat gliadin and celiac-toxic peptides.

The online version contains supplementary material available at 10.1007/s13197-024-05973-7.

Effect of cavitation treatment of coal-water slurries on a droplet average size in a jet

Relevance. Transition to environmentally friendly energy technologies, due to modern requirements for environmental protection, involves the search and creation of new energy sources, including fuels. One of the ways to meet these requirements and maintain the same level of energy production by thermal power plants is the transition to multicomponent fuels. The most promising and affordable boiler fuels from the point of view of energy, ecology and economy are coal-water slurries. In this regard, the study of the properties and characteristics of such fuels is relevant in many countries. Aim. Experimental studies of the effect of the coal-water fuel cavitation treatment duration on a droplet average size in a jet after spraying with a pneumatic nozzle and substantiation of the efficiency of such approach for practical application. Object. Experimental studies were carried out with coal-water slurries based on long-flame coal (D grade) with addition of 10 and 20 wt % by weight of pyrogenetic liquid. A slurry, consisting of just coal and water, without the addition of pyrogenetic liquid, was used as a reference sample. Method. The coal-water slurries were prepared in a rotary hydrodynamic cavitation generator. A pneumatic nozzle with external mixing was used to spray the coal-water slurries. The average size of fuel droplets after spraying was determined using the Interferometric Particle Imaging method. Results. Experiments on the preparation of coal-water slurries with pyrogenetic liquid showed an increase in the dynamic viscosity of the fuel. An increase in the duration of treatment of the slurries in a rotary hydrodynamic cavitation generator reduced the viscosity by 54%. The average size of droplets in the jet was reduced by 22%.

Research on Ultrasonic Cavitation Treatment of Milk. An Experimental Approach

Homogenization is a standard milk processing method used to stabilize fat emulsions against gravitational separation. In the dairy industry, high-pressure homogenization is commonly applied, which requires significant energy input to achieve optimal processing conditions. The size and composition of fat globule membranes affect the sensory and rheological properties of secondary dairy products [1]. Recently, ultrasound has been frequently used for milk homogenization [2]. Unlike ultrasound, mechanical mixing does not provide emulsion stability even after prolonged treatment, highlighting the differences between these two technologies. These differences arise due to the varying degrees of fat globule and membrane disruption. However, dairy products with different physicochemical and functional properties can be produced using both ultrasonic treatment and in combination with other traditional homogenization methods.To study the impact of ultrasonic treatment parameters of milk, specifically their different values, on the size of fat inclusions and the stability of milk emulsion over a certain period after treatment.The study employed an experimental method of milk processing using an ultrasonic cavitation unit.The impact of ultrasonic cavitation on the quality of milk homogenization in a steady volume was investigated. Optimal process parameters, specifically the power of the ultrasonic field and treatment time, were experimentally determined. The use of ultrasonic frequency greater than 33 kHz was found to be impractical.It was experimentally proven that ultrasonic cavitation treatment of milk is extremely effective for obtaining homogeneous emulsions. Given that excessive heating (> 65 °C) is undesirable in the production of dairy products from a technological standpoint, a definite advantage of this method is the low-temperature (50 °C) mode compared to traditional processing methods (75–80 °C), which also positively affects the preservation of nutrients.

Insight into the Effects of Hydrodynamic Cavitation at Different Ionic Strengths on Physicochemical and Gel Properties of Myofibrillar Protein from Tilapia (Oreochromis niloticus).

Effects of different ionic strengths (0.2, 0.4, and 0.6 mol/L) and different hydrodynamic cavitation (HC) treatment times (0, 1, 2, 3, and 4 min) on the conformation and gel properties of tilapia myofibrillar proteins (TMP) were investigated. The results showed that the solubility of TMP was significantly enhanced (p < 0.05) with the increase in NaCl concentration, and the gel characteristics were significantly improved. After HC treatment of TMP, the average particle size was significantly reduced (p < 0.05) and solubility was significantly enhanced (p < 0.05) with the increase in treatment time, the internal hydrophobic groups and reactive sulfhydryl groups were exposed. The intrinsic fluorescence spectra showed the unfolding of the spatial tertiary structure of proteins, and the circular dichroism spectroscopy showed the significant reduction in the content of α-helix in the secondary structure of the proteins (p < 0.05). In addition, the WHC and gel strength of the TMP heat-induced gels were enhanced, which improved the microstructure of the gels, and scanning electron microscopy showed that the gel network of the TMP gels became denser and more homogeneous. Dynamic rheology results showed that HC treatment resulted in a significant increase in the final G' and G" values of TMP. In conclusion, HC treatment was able to improve the physicochemical structure and gel properties of TMP at different ionic strengths. This study presents a novel processing technique for the quality maintenance aspect of salt-reduced surimi gel products.

The effect of cavitation treatment on the change in the carbohydrate composition of pumpkin puree

The effect of cavitation treatment on the change in the carbohydrate composition of pumpkin puree

The violent collapse of vapor bubbles in cryogenic liquids

Vapor bubbles in cryogenic fluids may collapse violently under subcooled and pressurized conditions. Despite important implications for engineering applications such as cavitation erosion in liquid propellant rocket engines, these intense phenomena are still largely unexplored. In this paper, we systematically investigate the ambient conditions leading to the occurrence of violent collapses in liquid nitrogen and analyze their thermodynamic characteristics. Using Brenner’s time ratio χ, the regime of violent collapse is identified in the ambient pressure–temperature parameter space. Complete numerical simulations further refine the prediction and illustrate two classes of collapses. At 1 < χ < 10, the collapse is impacted by significant thermal effects and attains only moderate wall velocity. Only when χ > 10 does the collapse show more inertial features. A mechanism analysis pinpoints a critical time when the surrounding liquid enters supercritical state. The ultimate collapse intensity is shown to be closely associated with the dynamics at this moment. Our study provides a fresh perspective to the treatment of cavitation in cryogenic fluids. The findings can be instrumental in engineering design to mitigate adverse effects arising from intense cavitational activities.

Degradation of diazine dye safranin T using potassium persulfate activated by ultrasonic treatment and MnFe2O4 spinel nanoparticles

An advanced oxidation process of ultrasound/MnFe2O4/K2S2O8 was developed for the degradation of diazine dye safranin T, according to which potassium persulfate was co-activated by ultrasonic (US) cavitation and MnFe2O4 spinel nanoparticles synthesized via co-precipitation in the ultrasonic field. A synthesis product annealed at a temperature of 4000C, with an average size of MnFe2O4 crystallites of about 7 nm, was used as a catalyst for the decomposition of potassium persulfate. Based on the results of experimental studies on the influence of various factors on the degree and rate constant of safranin T oxidative degradation, as well as considering energy and resource-saving principles, the rational conditions of oxidative degradation were determined as follows: the reaction medium temperature of 600C, the molar ratio of safranin T:K2S2O8=1:100, the catalyst loading of 0.1 g/l, and the specific power of the ultrasonic cavitation treatment of 51.0 W/l. It was established that under such conditions the oxidative degradation degree of safranin T was equal to 98.3%, and the rate constant was 1.510–3 s–1. The changes in the UV-Vis spectra of safranin T, namely a decrease in the intensity of absorption bands, both in the visible (at a wavelength of 520 nm) and in the UV (at a wavelength of 275 nm) regions of the spectrum, confirmed the degradation of safranin T. In addition, the absence of the appearance of new peaks in the visible and UV regions of the spectrum indicated mineralization of the dye.

Effects of ultrasonic cavitation on microstructure and surface properties of Mn–Cu alloy

In the presented study, the effects of ultrasonic vibration on microstructure and surface properties of Mn–Cu alloy were investigated. At the early stage of ultrasonic cavitation treatment, grains of Mn–Cu alloy are refined, nanocrystals and amorphous bands are produced. As the ultrasonic cavitation treatment proceeds, the face-centered cubic structure is transformed into the body-centered tetragonal structure, and the martensitic phase transformation arises. The transformation is accompanied by plastic deformation and the formation of dislocations. The generation of martensite is caused by the stress and strain. Due to grain refinement, dislocations, and generation of martensite, the surface hardness of Mn–Cu alloy is enhanced, and the friction coefficient decreases. The resistance to wear is thereby improved.

Applicability of hydrodynamic cavitation treatment of ash materials in sequestration and utilization of CO2

Applicability of hydrodynamic cavitation treatment of ash materials in sequestration and utilization of CO2

Comparison between hydrodynamic and ultrasound cavitation on the inactivation of lipoxygenase and physicochemical properties of soy milk

The effects of hydrodynamic cavitation (HC) and ultrasound cavitation (UC) on the lipoxygenase activity and physicochemical properties of soy milk were evaluated. The results revealed that both ultrasound cavitation and hydrodynamic cavitation significantly inactivated the lipoxygenase activity. After the exposure to ultrasound cavitation at 522.5 W/L and 70 °C for 12 min, the lipoxygenase activity was inactivated by 96.47 %. Meanwhile, HC treatment with the cavitation number of 0.0133 for 240 min led to the loss of 79.31 % of lipoxygenase activity. An artificial neural network was used to model and visualize the effects of different parameters after ultrasound cavitation treatment on the inactivation efficiency of soy milk. Turbiscan test results showed that hydrodynamic and ultrasound cavitation decreased the instability index and particle size of soy milk. Moreover, the total free amino acid content was significantly increased after hydrodynamic and ultrasound cavitation treatment. Gas chromatography-mass spectrometry showed that the total content of beany flavor compounds decreased after acoustic cavitation and HC treatment. Acoustic cavitation and HC affected the tertiary and secondary structure of soy milk, which was related to the inactivation of lipoxygenase. We aim to explore a potential and effective way of the application in soy milk processing by comparing the ultrasound equipped with heat treatment and hydrodymic cavitation.

Surface Properties and Cavitation Erosion Resistance of Cast Iron Subjected to Laser Cavitation Treatment

Laser cavitation is a novel surface modification technology using the impact of bubble collapse and laser-induced plasma to induce plastic deformation and produce compressive residual stress on material surfaces. The effects of laser cavitation on surface properties and the cavitation erosion resistance of cast iron were studied. In this work, three-dimensional morphology and residual stress distribution of the laser cavitation area under different laser parameters was obtained, the variation regularities of the topographic range and impact depth of the affected area was discussed, and the weight loss rate of cast iron under different defocusing amounts was studied. It was found that laser cavitation can effectively improve the anti-cavitation erosion property of the cast iron surface, and the optimal value was reached when the defocusing amount was H = 1 mm. Combined with the various defocusing amounts and the variation trend of the weight loss rate of cavitation erosion, the cavitation erosion time corresponding to each stage of the cast iron (incubation, rise, decay, and stability) was obtained.