Fine Removal Research Articles

Optimization of batch cooling crystallization systems considering crystal growth, nucleation and dissolution. Part I: Simulation

Optimal control of batch crystallization systems is still a focus and hot topic in the field of industrial crystallization, which seriously affects the consistency of batch product quality. In this paper, a new method with a new objective function and improved optimization algorithm was proposed for optimization of crystal size distribution (CSD) in case of fine crystals occurrence. The new objective function was developed with better margin metric and weighting technique to minimize fine crystal mass, meanwhile, a newly constructed sinusoidal weight function was introduced to improve the particle swarm optimization (PSO) algorithm. A precise control of CSD with suppressed numerical discrepancy caused by fine crystals removal was developed by combining seed recipe and temperature-swing. In addition, the effects of temperature curve segments on CSD during process optimization were systematically investigated to achieve optimal results. Two typical batch cooling crystallization systems were used to verify the effectiveness of the proposed method in controlling product CSD while minimizing fine crystal mass. Results demonstrated that the desired product CSD can be achieved with minor errors while the fine crystals could be shrunk to be negligible, i.e., the fine crystal mass and number can be reduced by over 90%. This work has an important guiding significance for the removal of fine crystals in industrial crystallization processes, especially when only operational optimization rather than equipment updating is considered.

Private Cctv Liability Under Biometric Data Protection Rules

The penetration of technology that is increasingly developing has a lot of impact on human life. Increasing technology also results in the rapid development of home security equipment, especially Closed-Circuit Television cameras (hereinafter mentioned as CCTV). The right to privacy, to which everyone is entitled to personal self- protection Doctrinal legal research is a crucial aspect in recognizing various societal problems. Doctrinal research combines a systematic analysis of the provisions of legislation and the legal principles contained in it or derived from it, but also the logical and rational order of legal propositions and principles. Doctrinal legal research methods involve the analysis of legal propositions or legal concepts on which the main study is based. Case base approach demands the researcher to understand the reasons that used by the judges or another adjudicator until it reaches the final decision. Most personal data protection laws around the world distinguish between regular personal data and biometric data. At the beginning, Article 4 paragraph (1) of EU GDPR regular personal data commonly define on the laws as a set of data that able to identify a natural person either from electronic or non-electronic devices. Under the data protection laws regime especially GDPR, UK Data Protection Law and Indonesia Data Protection Law, mitigation during a data protection failure involving household CCTV systems typically involves taking immediate steps to minimize the impact of the breach Furthermore, stated in the Fairhurst v Woodard case homeowner could be held liable for failure to protect the personal data if they use camera on the outside boundary of their house and they could face hefty fine and/or tools removal. Finally, this writing contributes to undergoing discourse on cyber law field especially in data protection law and provide insights for academician, practitioner, and society.

Study on the Permeability Enhancement of Propped Fractures under the Action of a Coal Fine Plugging Removal Agent.

The retention of coal fines in propped fractures impedes the efficient flow of gas and water, leading to a substantial decrease in coal seam permeability and gas production efficiency. In this article, a coal fine plugging removal agent with good dispersion stability and powerful powder-carrying capacity was developed to study the coal fine plugging removal and permeability enhancement in the propped fracture. The results show that 0.8% SDS + 0.4% NaCl + 0.8% BS-12 was the most effective coal fine plugging removal agent compounding system. Increasing the injection rate of the plugging removal agent and performing recycles of intermittent unblocking when it was used as a plugging agent will effectively enhance the gas-liquid two-phase effective permeability of propped fractures and improve the release of retained coal fines. After three recycles of intermittent unblocking, the coal fine discharging rate can be increased to more than 90%, resulting in a 3.88 times increase of the gas-liquid two-phase permeability compared to that with the single unblocking cycle. This method has important practical significance and theoretical value for solving the problem of coal fine plugging in fractures and ensuring the stable and efficient discharge of coalbed gas-water-coal fines.

Cleansing the molten steel due to the dispersed in-situ phase induced by the composite sphere burst reaction I. Composite sphere design

In the present investigation, a novel fine inclusion removal technology due to the dispersed in-situ phase induced by composite ball burst reaction was put forward. A composite sphere with this function was designed and the composite sphere burst process at steelmaking temperature was analysed. The results indicate that the compact strength of the composite ball is so high that it will not break up as it intrudes into the molten steel. The composite sphere has a high thermal stability at steelmaking temperature. Usually, the composite sphere burst reaction takes place after it has intruded into the molten steel for a few seconds. The fine bubbles and slag droplets can be released due to the composite sphere burst reaction. Compared with the conventional technology, the bubbles and slag droplets induced by this novel technology are much finer. The size distribution of the bubble and the slag droplet is between 20 and 200 μm. The dispersion of these fine bubbles and slag droplets contributes to collision with inclusion.

Cleansing the molten steel due to the dispersed in situ phase induced by the composite sphere explosion reaction II. Inclusion removal

Industrial trials have been carried out on the base of the former experimental research and the CaCO3 proportion in composite sphere, feeding amount, and composite sphere feeding mode have been investigated. The fine inclusion removal mechanism has been analyzed. The results indicate that feeding composite sphere in RH degasser is a novel process and small inclusion in the molten steel can be removed effectively. CaCO3/CaO ratio in composite sphere has a great effect on the inclusion removal efficiency. More feeding times and a little feeding amount can increase the composite sphere utilization efficiency. Compared with the conventional inclusion removal technology, the number density of the oxide inclusion can be decreased to a lower level and the inclusion size becomes much finer. Using this novel process, T.O. in the as-cast slab can approach to 6 ppm.

Investigation of cigarette effect and elastic-plastic behavior of green iron pellets on the roller screen efficiency

The green iron pellet demonstrates elastic–plastic deformation behavior during classification on a roller screen, which has a significant effect on its inefficiency due to the occurrence of phenomena such as the cigarette effect. This phenomenon causes the quantity and quality of produced pellets to drop by transferring the on-size pellets to the fine grain section and especially the oversized pellets to the product section. In this research, the effective factors in creating this phenomenon and the solutions to reduce it are investigated. It is observed that the optimum plastic behavior of the pellet and consequently the efficiency of the roller screen would be achieved when the green pellet is made from magnetite concentrate with 8 % moisture and 1 % bentonite, and roller screen operational parameters include feed rate of 1.5 t/h, the deck inclination angle of 13 degrees and the roll rotation speed of 150 rpm. The results obtained for the optimum fine removal efficiency, product screening efficiency, loss of production to undersize, on-size contamination, and oversize removal efficiency are 92.1 %, 93.7 %, 5.36 %, 5.23 %, and 73.2 %, respectively. The total screening efficiency of the roller screen is also estimated as 86.29 % and the cigarette effect is decreased to the most optimal state.

Remediation of Petroleum-Contaminated Gas Station Soil Using High-Pressure Soil Washing Technology

Objectives : In this study, high-pressure soil washing was performed on in-situ gas station soils for the remediation of petroleum-contaminated gas station sites.Methods : On-site gas station soils (GSS) collected from four different locations were subjected to high-pressure soil washing to analyze the amount of fine soil removal and TPH concentration after washing according to the cut-off size (0.075, 0.105 mm). In addition, the four GSS were evaluated for the relationship between the organic matter content of each soil and TPH removal efficiency. Furthermore, to evaluate the disintegration force of high-pressure soil washing technology to disperse soil aggregates, the particle size distribution of the soil before and after washing was evaluated and XRD analysis was performed.Results and Discussion : As the cut-off size increased (0.075 mm → 0.105 mm), the removal rate of fine soil in the GSS increased, and the TPH concentration tended to decrease. With respect to the TPH Soil Contamination Warning Standard for Region 2 (800 mg/kg), only the GSS 3 was in compliance with the standard (630 mg/kg). There were no significant differences in fine soil removal rates among the soils, which was expected since all the soils tested represented the same sandy loam. Washing efficiencies by soil were relatively low for soils with relatively high organic matter content. The particle size distribution showed the largest particle reduction was in the 2-0.850 mm range after remediation, while soil particles increased in the 0.105-0.075 mm and <0.075 mm range. In addition, XRD analysis showed an increase in the peak intensity of Quartz and the removal of clay mineral after washing, confirming the effective breakdown of soil aggregates and removal of fine soil by cavitation.Conclusion : If an optimal cut-off size is established, considering the soil texture and economics of the contaminated site after identifying the initial organic content level in the soil prior to washing, it is anticipated that high-pressure soil washing technology will be effectively applied for the remediation of petroleum-contaminated gas station sites.

Removal of fine solids from bitumen by hetero-aggregation and magnetic separation using surface-modified magnetite nanoparticles. Part 2: Role of surface modification

Stearylamine acetate (SAA) modified magnetite nanoparticles (MNPs) have been previously proven to significantly improve the efficiency of fine solids removal from cyclohexane-diluted non-aqueous extracted (NAE) bitumen following magnetic separation. In this work, asphaltene-modified magnetite nanoparticles (Asp-MNPs) were prepared, and their ability to remove fine solids from NAE bitumen was evaluated. The influence of the surface modification with SAA or asphaltene on MNPs in their interactions with NAE fine solids was studied through quartz crystal microbalance with dissipation monitoring and atomic force microscopy studies. It was demonstrated that modification by SAA increased the adhesion interaction between the MNPs and NAE fine solids through a bridging effect. The use of an external magnetic field also strengthened the hetero-aggregation between surface-modified MNPs and the NAE fine solids. Though the asphaltene modification of MNPs resulted in a repulsive behavior in the interaction between MNPs and NAE fine solids due to steric effect, the applied external magnetic field could drive the Asp-MNPs together and induce the bridging among the Asp-MNPs through an interdigitation process, and the NAE fine solids could be captured through a sweeping effect by the networked Asp-MNPs.

Study on Efficient Removal Method of Fine Particulate Dust in Green Metallurgy Process

In order to solve the problem of the low removal efficiency of fine particles in the flue gases of the metallurgy process, a chemical agglomeration pretreatment method was studied. The coagulant solution of xanthan gum, konjac gum, and their mixtures was selected to research the reunion effects of and the efficiency of gravitational dust removal of fine dust in the gas of the converter flue using a self-built experimental platform. Moreover, the effects of wetting agent type, dust concentration, pressure, and flue gas velocity on the fine grain removal efficiency were investigated. The results showed that the mixed solution of 1 g/L mixed gum and 0.5 g/L SDS had the most obvious effect on the particle size increasing of fine dust particles and the best removal effect when the flue gas velocity was 10 m/s. There was a peak particle size of 85.32 μm increased about eight times larger, and the removal efficiencies reached 51.46% for PM2.5 and 53.13% for PM10. The Box–Behnken experimental design combined with a response surface analysis method was used to optimize the parameters of the mixed gum concentration, pressure, and flue gas velocity. The optimal removal conditions were 1 g/L, 0.4 MPa, and 10 m/s. The results of this study can provide efficient methods and technical support for pre-processing and efficient removal of fine particles in heavy-polluting industries such as steel making. This will promote the green development of the metallurgical industry.

Assessing the impacts of fine sediment removal on endogenous pollution release and microbial community structure in the shallow lakes

Resuspension is a crucial process for releasing endogenous pollution from shallow lakes into the overlying water. Fine particle sediment, which has a higher contamination risk and longer residence time, is the primary target for controlling endogenous pollution. To this end, a study coupling aqueous biogeochemistry, electrochemistry, and DNA sequencing was conducted to investigate the remediation effect and microbial mechanism of sediment elution in shallow eutrophic water. The results indicated that sediment elution can effectively remove some fine particles in situ. Furthermore, sediment elution can inhibit the release of ammonium nitrogen and total dissolved phosphorous into the overlying water from sediment resuspension in the early stage, resulting in reductions of 41.44 %–50.45 % and 67.81 %–72.41 %, respectively. Additionally, sediment elution greatly decreased the concentration of nitrogen and phosphorus pollutants in pore water. The microbial community structure was also substantially altered, with an increase in the relative abundance of aerobic and facultative aerobic microorganisms. Redundancy analysis, PICRUSt function prediction, and the correlation analysis revealed that loss on ignition was the primary factor responsible for driving changes in microbial community structure and function in sediment. Overall, the findings provide novel insights into treating endogenous pollution in shallow eutrophication water.

Role of Physics for Development of Different Techniques for Photocatalytic Degradation of Heavy Metals and Effluents in Water

Several factors contributed to the elevated levels of water pollution in the earth surface increasing the risk of wastewater pollution. Inorganic metal irons and suspended liquid metals are also leads cause of water pollution. Physical treatments for water treatment include the use of effective membrane filters in two ways. Small membrane filter and large membrane filters also used for commercial applications. Different types of nanoparticles are used for the treatment of organic contaminants suspended in the wastewater. The adsorption of a reactive dye through the hydroxyapatite (HAP) leads the excellent filtration of ions in the wastewater. Different types of photocatalytic reactors are used for the treating the large amount of wastewater in effective ways. These included the titanium based photocatalytic reactors that employed the sub-micron TiO2 particles from the treated water which accompany the treatment process. Polymer composites are used for removal of wastewater due to their low operating temperat Nanofiltration also used for removal of wastewater due to the formation of utilizing of the semipermeable membrane allows the fine removal of the different ions and different types of pollutants ure and susceptibility to environmental degradation as compared to other operations.

A New Method for Continuous Classification of Fine Catalyst Particles from a Slurry Bed Fischer–Tropsch Reactor

During the operation of an industrial Fischer–Tropsch plant, fine catalyst particles are continuously generated in the slurry bed, which results in a series of problems, such as reduced flowability of liquid from the filter, reduction of unit processing capacity, and increased catalyst consumption. To solve these issues, a new classification method based on hydrocyclone was proposed to classify fine particles continuously. Cold model experiments using a mimic liquid–solid medium were conducted to verify the feasibility of this new method. The optimized structure and operating conditions were determined by studying the influences of structural parameters, operating conditions, and material physical properties systematically. Side-stream tests were then conducted to evaluate the actual classification performance. The results showed that the performance of the new classification method is primarily influenced by the medium temperature, i.e., the liquid viscosity. When slurry temperature is 200 °C, the coarse loss ratio can be reduced to less than 5% in a single-turn classification test and the fine removal ratio can be maintained at around 30%. With further increases in the temperature (i.e., at lower liquid viscosities), better classification performance can be expected. Finally, a prediction model was established, which can predict the whole classification performance of the new classification method. The model can be used to guide the process design and operation of this method.

Phyllosilicate-based adsorbents decorated with iron oxyhydroxides: Application for lead, chromates and selenites removal

Expanded vermiculite (EVer) was acid activated and silanized in order to obtain suitable substrate?s surface for decoration with iron oxyhydroxides (IO). Obtained activated sample (EVa), was decorated by deposition of either prevailing goethite or amorphous iron oxyhydroxides (AIO) resulting in EV-A and EV-B adsorbent, respectively. Modifications of EVa showed improved adsorption performances when used as adsorbent of lead, chromates and selenites. Adsorption experiments conducted in a batch and column system demonstrated good potential for purification of water contaminated with Pb2+, Cr(VI), and Se(IV). Equilibrium adsorption capacity of EV-A in relation to Pb2+ and Cr(VI) were 48 and 54 mg g-1, respectively, while EV-B showed even better effectiveness for Se(IV) achieving 120 mg g-1 capacity. Regeneration of pollutant saturated adsorbents approved that prepared adsorbents possess fine removal potency even after five adsorption/desorption cycles from 87.58 (for Pb2+/EV-A) to 92.81 % (for Cr(VI)/EV-A) of initial adsorption capacity.

Numerical Investigation of Fine Particulate Matter Aggregation and Removal by Water Spray Using Swirling Gas Flow

In this paper, a mathematical model based on the two-fluid frame model coupled with the population balance model which considers the aggregation of particles and droplets in detail for cyclonic spray dedusting is proposed. The model is applied to study the characteristics of multiphase flow field and the effects of the gas velocity, spray volume, and particle concentration on the removal efficiency. In addition, the simulation results are verified by the experimental data. The results suggest that the turbulence kinetic energy increases near the wall as the inlet velocity increases, and the spray region increases as the spray volume increases. This is conducive to turbulent mixing of the particles and droplets, and the agglomeration efficiency of the particles is improved, so the particle size increases, and the particle removal efficiency increases to 99.7% by simulation results are within the allowable range of error (about 99-99.5% in dedusting efficiency by experimental data). As the particle concentration increases, the particle removal efficiency initially increases, then decreases and reaches the highest value at 2 g/m3, which is due to the limited adsorption efficiency of the spray droplets. The results are helpful for providing a theoretical basis for spray to promote agglomeration of particles and improving the dust removal efficiency in the swirl field.

Numerical simulation and optimization of coupled demister with directing and perforated plate in MSF plants

The coupled demister with directing and the perforated plate was proposed in this work, which was applied in the fine droplets removal process for the multistage flash (MSF) desalination process. The performance was evaluated with three criteria, overall particle removal efficiency, pressure drop, and impact factor. The results show that the main influencing factors of the performance of the directing plate mist eliminator are the directing plate length, the installation upper wall angle, and the installation position. The interaction effects occur while two individual directing plates are installed. For improving the fine droplets removal performance, perforated and directing plate coupled mist eliminator was designed, and the results show that the coupled mist eliminator has the best performance compared to the others. The particle separation efficiency is significantly improved, and the efficiency can reach >93.75 %, Euler number is only 5.54, compared to individual structural design, the pressure drop declined and particle removal efficiency increased significantly. Besides, the coupled mist eliminator has a simple structure and can be processed by integrated technology. All these advantages make the directing and perforated plate coupled mist eliminator a promising candidate for fine droplet removal in the MSF desalination process.

Effects of different plant communities on fine particulate matter concentrations in green areas around Quancheng Road, Jinan

To study the effect of different plant communities on fine particulate matter PM2.5 and PM10 concentrations in green areas attached to urban roads is an important basis for improving the air pollution control function of urban green areas and optimizing the configuration of green areas, and it can provide an optimal solution for plant configuration selection. In this paper, the intersection of Quancheng Road and the front street of the provincial government in the Lixia District of Jinan City was selected as the research object, which has certain research value because of its important political and commercial functions and therefore has a large flow of people and vehicles. The CEM DT-9880 particle counter was used to measure the concentration of fine particulate matter at 1m and 2m height, respectively, and to analyze and compare the effect of different plant communities on fine particulate matter concentration and dust removal ability. The design optimization strategy of road accessory green space was proposed to regulate and improve the fine particulate matter.

Eccentric sleeve grinding for thermal management and dry grinding of carbon fibre reinforced composites

Precision machining of Fibre Reinforced Polymer (FRP) Composites needs to be explored further while addressing advanced engineering applications. However, force and temperature-driven damages while machining FRP composites, due to the non-homogenous and low thermal conducting behaviour of fibre-matrix interfaces, place the barrier in this direction. Surface machining using abrasive wheels has been projected as a promising option for fine removal of material in FRPs. However, conventional dry grinding strategy exhibited high grinding force due to continuous interaction of abrasive cutting edges, leading to accumulation of heat at the grinding interface. As the cutting action is continuous, heat dissipation also becomes difficult in this situation. Temperature-driven damages on composite matrix and subsequent failure of reinforced fibres were serious concerns in this case. Although attempted in some situations, usage of cutting fluids was not recommended fully due to wetting effects and agglomeration of swarf that hinder the grinding efficiency. Eccentric Sleeve Grinding (ESG), using an intermittent-progressive cuttings scheme, is proposed in this work as a potential dry grinding strategy for FRPs. Control of heat accumulation through progressive cutting strategy and enhancement of heat dissipation through intermittency in cutting cycle appears to be the unique characteristics of ESG. Experimentation of ESG on carbon fibre reinforced composite samples showed promising grinding temperature reduction, which was justified through a significant reduction in grinding forces, surface defects and roughness.

Removal of fine solids from bitumen by hetero-aggregation and magnetic separation using surface-modified magnetite nanoparticles. Part 1: Proof of concept

Separation of fine particles suspended in liquid is crucial yet difficult and inefficient in various engineering processes. In the oil sands industry, high fine solids content in produced bitumen is one of the hurdles preventing non-aqueous extraction (NAE) from being used in commercial operations. This work proposed a novel method for fine solids removal from NAE bitumen by hetero-aggregation with surface-modified magnetite nanoparticles followed by magnetic separation. Stearylamine acetate-functionalized magnetite nanoparticles (SAA-MNPs) were prepared and characterized, and the separation performance of fine solids from NAE bitumen by the proposed approach using SAA-MNPs was quantitatively evaluated and compared with un-modified magnetite nanoparticles (MNPs). It is demonstrated that after functionalization with SAA, the separation effectiveness was significantly improved. Hetero-aggregates between the NAE fine solids and SAA-MNPs were shown to be formed in cyclohexane. The present work provided a promising approach of combining hetero-aggregation and magnetic separation for the purification of hydrocarbon products such as Alberta oil sands bitumen.

External fine particle removal for crystallization processes: Introduction and systematic comparison with the temperature cycling-based fines removal

Intermittent small particle removal is frequently used for particle property improvement in batch crystallization processes. This is generally solved by partial dissolution cycles, which for a cooling crystallization translates to temperature cycles - well suited for small-scale experimentation. However, implementing temperature cycles on a larger scale may face technical difficulties. This paper investigates a concept for fine particle removal, namely, the controlled external fines removal. Here, controlled dissolution is achieved in an external environment being attached to the crystallizer via a recirculation stream. Simulation-based external and internal fines removal is compared. The population balance model involves primary and secondary nucleation as well as crystal growth and dissolution. A two-level control system is developed: the low-level PI controller sets the vessel's temperature, whereas direct nucleation control (DNC) alternates between growth and dissolution cycles based on the actual particle number density. The paper demonstrates that the external fines’ removal results in slightly but consistently larger particles and a narrower size distribution in the majority of cases. Under optimal conditions, external fines’ removal leads to shorter batch times, and its convergence is significantly less sensitive to the DNC settings e.g., heating/cooling rates. From an energy utilization perspective, the internal fines removal requires less cooling and heating energy than the external configuration. The external configuration has great energy saving potential through heat integration as during the constant temperature recirculation the simultaneous heating and cooling duties in the crystallizer and heat exchanger match each other.

INVESTIGATION OF THE INTENSIFICATION OF SEPARATION PROCESSES USING THE HEAT OF EXHAUST GASES

The useful use of heat for the above cases is primarily related to the use of heat from the exhaust gases. It should be stressed that in all cases it is necessary to return the maximum amount of waste heat to the process. Part of the heat is usually returned to the working chamber with heated air (up to 300 - 500 oC). In some cases, it is possible to use a certain amount of gas heat for drying and heating the raw material, the finished product and/or for heating the process water used in the processing; the use of heat from gases to produce steam and other parameters for the necessary heating of the blast furnace. All of this opens up the possibility of achieving very high end results for energy plants. However, as a rule, the exhaust gases are characterized by fairly high concentrations of fine solid particles (fine removals), which must be effectively removed in the separator because in most cases they prevent the efficient use of heat from the exhaust gases. Thus, efficient separation of fine removal is crucial for heat recovery of exhaust gases, especially for high-performance units. The ways to intensify the separation processes in industrial waste were investigated and made practical conclusions. Based on known literature data and results of own experiments, some questions of separation of fine removal are considered. The basics of the separation mechanism are formulated, which are reduced to elucidating the causes and patterns of movement of small particles to the separating surface across the main stream. The mechanisms of separation of small particles due to turbulent diffusion are analyzed in detail, the possibility of realization of the mechanism of separation on the basis of thermophoresis is estimated. The initial parameters and criteria that characterise the particle separation process have been established. A formula for assessing the particle separation rate is derived and the effect of the specified criteria on this value is analyzed. The analysis of the above dat a resulted in practical conclusions on ways to intensify the separation processes under industrial conditions.