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Removal and/or prevention of limescale in plumbing tubes by a radio-frequency alternating electric field inductance device
Abstract
Fouling problems due to limescale formation are of major concern to many industries. Deterioration of heat transfer equipment performance and substantial increase of pressure drop across piping systems comprise the main problems, resulting in high machinery-maintenance cost and decreased productivity. Limescale removal techniques, like scraping, hydro-blasting, and the use of aggressive chemicals, shorten the life of pipes and machinery. Furthermore, limescale prevention techniques in industrial scale, like ion-exchange or reverse osmosis , require expensive equipment and heavy maintenance. In this paper, an electronic antifouling device is presented which, not only prevents limescale formation, but also removes existing scale in plumbing tubes, at insignificant energy consumption. Induction of a Radio-Frequency Alternating Electric Field (RFAEF) in water at a specific range of frequency and antenna voltage, along with its distinct sinewave waveform, changes the way minerals precipitate, minimizing hard-lime scale by producing instead a non-adherent mineral powder in the bulk water. Moreover, the unsaturated solution that is created, along with enhanced carbon dioxide production, dissolves gradually the existing scale in plumbing tubes. Furthermore, the RFAEF inductance device demonstrates a major improvement over other pulsed-power systems, proving this electronic antifouling technique suitable for both hard and soft waters, as well as for large-scale applications.
... To ensure the efficient production of concentrators, the dynamic water system often requires descaling [2]. Therefore, for energy conservation and environmental protection purposes, it has become increasingly important to seek economic and efficient methods of scale prevention and descaling to provide technical support for normal mineral separation and index stability operations [3][4][5]. ...
... The water quality used in the concentrator contains Ca 2+ and Mg 2+ , which react with CO 2 and CO 3 2− in water and form inorganic salts such as CaCO 3 ; these salts are difficult to dissolve in water and gradually become sediment [6,7]. Considering the causes of scale formation, the primary methods of scale removal are mechanical, chemical reagents and high-pressure water gun sprays. ...
... The water quality used in the concentrator contains Ca 2+ and Mg 2+ , which react with CO 2 and CO 3 2− in water and form inorganic salts such as CaCO 3 ; these salts are difficult to dissolve in water and gradually become sediment [6,7]. Considering the causes of scale formation, the primary methods of scale removal are mechanical, chemical reagents and high-pressure water gun sprays. ...
Magnetization technology has been widely used in various transportation pipeline anti-scaling and descaling processes due to its simple equipment, low operating cost and low secondary pollution. To resolve structural pipeline issues in concentrations, the effects of magnesium salt concentration on conductivity, pH value and calcium ion concentration of a magnetized calcium chloride sodium bicarbonate mixed solution were studied. The results indicated that 4.0% MgSO4 had the greatest anti-scaling effect under dynamic water conditions, which increased the calcium concentration of the mixed solution by 5.93%. Furthermore, the synergistic effects of 5.0% magnesium carbonate on the scaling of calcium carbonate were the largest, which reduced the calcium concentration of the mixed solution by 22.19%. Scanning electron microscope (SEM) and Raman spectra showed that magnesium carbonate reduced the effects of magnetization because it inhibited the formation of vaterite-type calcium carbonate and promoted the formation of calcite-type calcium carbonate. Magnesium sulfate can improve the anti-scaling effects of magnetization because it promotes the formation of vaterite calcium carbonate with high solubility. The results of this study can provide a theoretical basis for the scaling process and dissolution behavior regulation of calcium carbonate and have an important reference significance for scale prevention and scale removal in concentrator pipelines.
... Scale refers to the crusty chalky or soft muddy substances that gradually accumulates on the solid surface in contact with mineral ion-containing fluids [1] . ...
... Ca 2+ + 2HCO3 − ⇄CaCO3(s) + H2O+CO2(g) (1) Fouling phenomena are widespread in the heat transfer process of industrial production [5][6] . Examples include thermal power, petroleum, desalination, and food industries. ...
Electric field scale inhibition is one of the most promising methods of scale inhibition. In this study, an alternating variable frequency electric field device is presented, it able to prevent the growth of scale in industrial heat exchange equipment effectively. Conduct field test at the heat exchange station to analyze the scale inhibition performance of the device. The test results showed that after using alternating variable frequency electric field device, the scale thickness on the heat exchange surface is significantly reduced, fouling resistance reduced by more than 58%, and the anti-corrosion rate for Fe element content reaches 19.78%, The SEM image of the scale changes from a dense irregular sharp shape to a loose spherical shape. Conclusively, alternating variable frequency electric field device has grate scale inhibition performance. This is of great significance to the field of heat transfer and energy saving.
... On many surfaces where a deposit layer forms and evolves, the surfaces are stationary. Broadly speaking, these include salt crystallization on rock surfaces, 1 alluvial deposition on riverbeds, 2 limescale formation in piping systems, 3 asphaltene deposition in oil wellbores, 4,5 wax deposition on sub-sea oil pipelines, 6 dust deposit on solar panels, 7,8 fouling in heat exchangers [9][10][11] and heating surfaces. 12 In addition to stationary surfaces, a deposit layer also grows on the surfaces of objects undergoing either prescribed or free motion, or even deformation. ...
This work presents a numerical model to study the effects of deposition and deposit erosion on a solid moving object under prescribed motion. In this model, fluid flow, particle transport, particle deposition and deposit erosion, conjugate heat transfer, and object movement are all considered simultaneously in a fully coupled manner. The deposition is modeled as a first-order reaction, while shear-driven erosion is modeled using a threshold law. The evolution of the deposit front and the moving object is captured using the level-set method with two level-set functions. The capabilities of the numerical model are demonstrated on a flat plate undergoing translational, rotational, and combined motions, as well as on a four-blade rotor undergoing translational and rotational motions. The results indicate that higher deposition typically occurs on the upstream facing surface of the moving object due to the higher particle concentration in this region compared to that of the downstream region. With an imposed volumetric heat generation within the solid object, the deposit layer acts as an insulating barrier, impairing heat transfer from the solid object to the flowing fluid and leading to a higher average temperature of the solid object compared to that of clean object. Furthermore, the total deposit volume increases with higher Damkohler numbers and critical shear stress, as well as with lower Erosion numbers. Consequently, the average solid object temperature rises with the increase in the total deposit volume.
... There is a major distinction between applying EF and EMF to fluids , namely, EF is applied to the fluid through direct contact with conductive electrodes, while EMF is applied to the fluid through induction (without any direct contact). The application of EF has shown to be effective in the removal and/or prevention of scaling in pipes (Tijing et al., 2010;Georgiou et al., 2018;Kim et al., 2011). So far, in the environmental context, the effect of EMF inductance has been studied on scale/fouling prevention and removal (Xuefei et al., 2013), (Stefanini, 1997), prevention of corrosion and scale formation in oilfield extraction wells (Rzeznik et al., 2008;Stefanini, 2011;Stefanini, 2012), and controlling biofilm formation and bacterial growth (Caubet, 2004) Enhancing the effectiveness of antibacterial agents against microorganisms is another capability of EF, which is also known as the "bioelectric effect" (Del Pozo et al., 2008), discussed by Costerton et al. (Costerton et al., 1994). ...
Landfill Leachate (LFL) treatment is a challenging and complex issue. One such difficulty is biofouling and bio-clogging caused by the rich microbiome of the LFL. In this study, the effect of Radio Frequency Electromagnetic Field (RFEMF) inductance on the microbial inactivation of LFL has been investigated for the first time, and it is shown that RFEMF alone can result in 24-35% reduction in LFL microbial count. Meanwhile, the application of the field alongside pH adjustment is shown to significantly reduce the bacterial count of the LFL, from over 9×10⁴ CFU/mL to under 1.5×10⁴ CFU/mL under optimum conditions. In other words, the application of RFEMF with pH adjustment shows very strong synergetic effects, increasing the effectiveness of the treatment more than two-fold. The reason for this observation is the damage caused to the cell membranes via pH adjustment, making them particularly vulnerable to the effects of the RFEMF. This study offers a low-cost and simple method for disinfection, and highlights an avenue of research on microbial inactivation, not just for LFL but possibly for other wastewater streams as well.
... The presence of dissolved salts causes inorganic fouling, which impacts industries such as pharmaceuticals, 1 desalination, 2 oil and gas, 3 hydrometallurgy, 4 and cooling towers, 5 and poses challenges in a variety of practical applications ranging from residential plumbing to industrial boilers. 6 The efficiency of the heat transfer surfaces is severely compromised due to scaling. For example, the energy lost due to the fouling of heat exchangers amounts to at least 2% of the total world energy production per year. ...
In the present work, we investigate the influence of substrate wettability and crystal morphology on the evaporative crystallization of saline droplets. On a superhydrophilic substrate, the evaporative crystals formed during the drying of a saline droplet of aqueous potassium nitrate are observed to be long and needle-shaped, oriented along the substrate. The crystal deposits form a flower-shaped pattern when the initial contact angle of the droplet increases to ∼72°. The orientation of the crystals along the triple contact line of the droplet controls the self-amplifying creeping growth of the salt crystals that eventually determines the overall evaporative patterns. The crystals change from being needle-shaped to globular salt deposits as the volume of liquid available for crystallization reduces. We demonstrate that the arrangement of the crystal with respect to the substrate and the droplet–air interface governs the rate of evaporation, growth, and morphology of the crystals.
... According to a review of the literature on treating fluids with RF, the most common areas of research appear to be prevention of fouling and scale formation in plumbing tubes and heat exchangers [15][16][17][18]; prevention of scale formation or corrosion of oilfield extraction wells [19], [20]; control and killing of bacterial biofilms [18], [21]; and treatment of dye-containing wastewater [22].However, to the best of the authors' knowledge, the effect of RF inductance on LFL has not been studied yet. More specifically, this study has the following three objectives: (i) evaluate the effect of RF inductance on decolorization; (ii) evaluate the effect of RF inductance on coagulation and settling of coagulant flocs; and (iii) evaluate the effect of RF inductance on reduction of bacterial count. ...
The use of radio frequency for water and wastewater treatment is a topic that has not been extensively explored. In this study, the effect of a HydroFlow S38 device (Hydropath Holdigs) inducing 150 KHz radio frequency (RF) has been investigated, removing color, forming coagulant flocs and their sedimentation, and the removal of bacteria. Experiments were first conducted on synthetic samples, and then on landfill leachate from the Aradkooh waste processing and landfilling complex (Kahrizak) in Tehran, Iran. The results of the experiments showed that RF had little to no effect on de-coloring in the absence or presence of sodium hypochlorite. Also, the coagulation and flocculation of ferric chloride remained unaffected. However, the use of RF was shown to reduce the number of bacteria significantly. The inductance of RF alone, without any other aid or chemical/physical treatment, was able to reduce the bacterial count by 35%. These findings provide motivation for future research regarding the use of RF for bacteria inactivation.
... Due to the large amount of Ca 2þ and Mg 2þ ions in the circulating cooling water (Rahmani et al. 2016;Yu et al. 2017), it is easy to form scale on the heat transfer surface, which leads to an increase in energy consumption and a decrease in heat transfer coefficient. It is very important to soften the circulating cooling water (Brastad & Zhen 2013;Georgiou et al. 2018). ...
In order to promote the application of electrochemical water softening technology in industrial circulating cooling water systems, electric field type, cathode structure and solution residence time are selected for optimization analysis of an electrochemical water softening device. The experimental results show that the water softening performance per unit area of mesh cathode is better than that of a plate cathode. In addition, the softening amount per unit area of the mesh cathode can be further increased when the high-frequency (HF) power supply is applied. When the HF power supply is applied, the softening amount per unit area is 158.58 g/m2·h−1 more than when the direct current power supply is applied. In order to explore the growth mechanism of calcium carbonate, micro-analysis technology and high-speed bubble photography technology are used. The results show that the bubbles escape along the longitudinal direction of the electrode plate, and the main growth direction of calcium carbonate growth is consistent with the escape direction of the bubble; that is, the bubbles grow along the longitudinal direction of the electrode plate. The special structure of the diamond-shaped mesh cathode facilitates the growth of calcium carbonate crystals. HIGHLIGHTS
The high-frequency power supply can further increase the descaling amount per unit area of the mesh cathode.;
The special structure of the diamond-shaped mesh cathode facilitates the growth of calcium carbonate crystals.;
The maximum desalination rate of this experimental device is 604.5 g/m2 h−1.;
... Nowadays, when the industry touches the high pressure on optimization of energy and time consumption in parallel to the high production quality, the crystallization process, known for over 100 years, can meet these requirements. It is an integral part of productions' lines in many areas of industry as food production (sucrose) (R ozsa, 1996;R ozsa et al., 2016;Temerk et al., 2014;Villanueva et al., 2015), pharmacy (drugs) (Besenhard et al., 2014;Gao et al., 2017;Shekunov and York, 2000) but also in chemical flows (limescale in pipelines) (Butler et al., 2006;Georgiou et al., 2018), nanoparticles and polymerization (Hierzenberger et al., 2010;Ohta et al., 2005). That is why many research teams are dealing with the task of developing new methods for diagnosis, modeling, and control of crystallization processes (Fujiwara et al., 2005;Gao et al., 2017;Jha et al., 2017;Winn and Doherty, 2000). ...
Purpose
Crystallization is the process widely used for components separation and solids purification. The systems for crystallization process evaluation applied so far, involve numerous non-invasive tomographic measurement techniques which suffers from some reported problems. The purpose of this paper is to show the abilities of three-dimensional Electrical Capacitance Tomography (3D ECT) in the context of non-invasive and non-intrusive visualization of crystallization processes. Multiple aspects and problems of ECT imaging, as well as the computer model design to work with the high relative permittivity liquids, have been pointed out.
Design/methodology/approach
To design the most efficient (from a mechanical and electrical point of view) 3D ECT sensor structure, the high-precise impedance meter was applied. The three types of sensor were designed, built, and tested. To meet the new concept requirements, the dedicated ECT device has been constructed.
Findings
It has been shown that the ECT technique can be applied to the diagnosis of crystallization. The crystals distribution can be identified using this technique. The achieved measurement resolution allows detecting the localization of crystals. The usage of stabilized electrodes improves the sensitivity of the sensor and provides the images better suitable for further analysis.
Originality/value
The dedicated 3D ECT sensor construction has been proposed to increase its sensitivity in the border area, where the crystals grow. Regarding this feature, some new algorithms for the potential field distribution and the sensitivity matrix calculation have been developed. The adaptation of the iterative 3D image reconstruction process has also been described.
Antifouling coatings stand out as one of the highly efficient ways to mitigate surface contamination. Traditional antifouling coatings have a major drawback: they rely on highly toxic and environmentally hazardous compounds. These substances not only lead to ecological harm but also disrupt the natural equilibrium of ecosystems. Consequently, in recent years, eco-friendly antifouling bio-coatings have emerged. This review focuses on the mechanisms and processes underlying contaminant adhesion, laying a solid foundation for grasping the principles of antifouling coating design. It further elaborates on the general strategies for developing bio-based antifouling solutions, highlighting their potential across a wide array of applications. Finally, this review carefully analyzes the current challenges confronted by antifouling bio-coatings and puts forward future development directions. Through a comprehensive overview, we aim to expand the influence of bio-based antifouling technologies, promote the further application of bio-based antifouling coatings in marine antifouling and medical antifouling fields, and provide examples for the establishment of environmental protection policies.
We propose a novel approach to characterize the growth of individual crystals. Calcium chloride and sodium carbonate solutions have been injected into a Y-shaped microfluidic channel at various stoichiometric ratios, and the development of calcium carbonate has been monitored. The formation of calcite and vaterite depends not only on the stoichiometric ratio of the reactants but also on the region of the reactor where they form. From the crystal images, we have mapped the surface growth of the particles and have shown that closer to the confluence of the microchannel the crystal growth is significant. Both morphologies mainly form in the carbonate-rich zone, supported by numerical modeling. Moreover, the side growth of the calcite particles is diffusion-controlled and independent of the crystal orientation and the stoichiometric ratio of the reactants injected.
The deposition of the CaCO3 crystals in circulating cooling water is crucial to industrial water softening, which is beneficial to avoiding internal scaling and improving production efficiency. This paper focuses on the practicability of electrochemical techniques to analyze the influence of pulse current on the electrodeposition of CaCO3 in blank and high salinity conditions, including linear sweep voltammetry, chronoamperometry and electrochemical impedance spectroscopy tests. We assessed the coverage and compactness of the CaCO3 scale layer by obtaining residual current density (ir) and polarization resistance (Rp) values. Electrochemical results revealed that pulse electrodeposition can generate a more compact CaCO3 scale layer by Ostwald ripening, while the salt effect of NaCl can inhibit the nucleation and growth of CaCO3 crystals. Scanning electron microscope and X-ray diffractometer tests showed that unstable CaCO3 crystals can be dissolved and the size of calcites had changed with Ostwald ripening. Longer pulse-off time is beneficial to Ostwald ripening of CaCO3 crystals and nucleation in the first and second periods can influence the size of calcites formed under pulse current.
Mineral scale formation is a major operational challenge in oil and gas fields that always comes with a high cost. Thus mineral scale must be detected early and managed to avoid detrimental impacts. Scale management involves preventing scale formation and removing the formed scale. Scale prevention can be achieved by means of operational, chemical, and nonchemical methods. Operational means are based on optimizing the process parameters to avoid solids precipitation and deposition the chemical methods are based on using chemical inhibitors; and the nonchemical methods are based on using physical methods that change the fluid properties to be nonscaling. Scale removal methods are based on chemical methods using dissolvers, and nonchemical methods using physical and mechanical means. In this chapter, mineral scale management is addressed, and a comprehensive scale management strategy is outlined in light of recent advances.
The electromagnetic frequency is one of the most important parameters in electromagnetic scale inhibition research, and most of the previous studies on the optimal frequency range used experimental analysis. In this paper, a computational model for the optimal frequency of CaCO3 scaling in copper pipes under the action of electromagnetic fields is introduced. By establishing the equivalent electric dipole pipeline physical propagation model of the two-layer medium of the pipe wall and the water body, the vector magnetic potential in the water body is deduced by the mirror method, and the electromagnetic field expression of the water body in the pipe is derived. According to the electromagnetic energy relationship, the optimal electromagnetic frequency range is calculated to be 70–75 kHz. Finally, experiments were performed to analyze the effect of electromagnetic fields in different frequency ranges on the scaling of CaCO3 in copper pipes, and the obtained results verified the accuracy of the optimal frequency calculation model for CaCO3 scaling in copper pipes under the action of electromagnetic fields.
This study aims at inhibiting the formation of calcium carbonate in heat exchangers by using guided ultrasonic waves associated with the heterodyne effect of multiple frequencies. To provide a proof of concept, an experimental approach on a plate and joint heat exchanger was considered and complemented by a modeling approach. This study explains how to identify areas susceptible to calcium carbonate deposition. The scaled surface is analyzed using a 3 D digital microscope, the preferential deposition areas are identified and the fraction of the surface occupied by calcium carbonate is determined. In addition, modeling was performed to detect areas sensitive to temperature and fluid flow. The modeling was validated using experimental data from a scaled plate analyzed with a 3 D microscope. As a predictive tool, this model could be particularly useful in identifying effective strategies to mitigate or even eliminate fouling.
Because of the electric field method has the characteristics of energy saving, environmental protection and high efficiency, it is the focus of research in this field at present. In this study, a molecular dynamics method was used to simulate the effect of an electric field on the interaction of Ca2+ and CO32− in calcium carbonate solution with the surface of calcite crystals (1, -1, 0), and through experiments, the performance of an electric field with an intensity of 1000–1400 V/m (step 100 V/m) to inhibit calcium carbonate deposition on the heat transfer surface was studied. The simulation results showed that the binding energy of Ca2+ and CO32− to the surface of calcite crystals (1, -1, 0) decreased after the application of an electric field. By analysing the diffusion coefficient and radial distribution function of Ca2+ and CO32−, the electric field was shown to effectively prevents the diffusion and combination of to the calcite (1, -1, 0) crystal plane, which can effectively prevent the growth of calcium carbonate on the heat transfer surface. The experimental results showed that the fouling resistance is significantly reduced after electric field treatment. The results of scanning electron microscopy (SEM) and macroscopic analysis of fouling on heat transfer surface also show that electric field can effectively inhibit fouling. When the electric field intensity is 1300 V/m, it has the best anti-scaling effect. Therefore, the calculation results are basically consistent with the simulation conclusions.
The present study introduces an alternating electric field device that can effectively inhibit the growth of scale on industrial heat exchangers. The 5–70 V voltage and alternating electric field (AEF) of 80–300 kHz frequency are transferred by the device in water where they can inhibit scale formation on tube walls by changing the precipitation mode of mineral ions. After the alternating electric field device is used, the scale thickness on the heat exchange surface becomes significantly thinner, and the maximum fouling resistance decreases by 58% (from 8.54 10−4 m2K/W to 3.58 10−4 m2K/W). Scanning electron microscopy (SEM) results show that after the use of the alternating electric field device, the scale on the heat exchange surface changed from dense crystals with irregular, sharp shape to loose crystals with spherical shape, and X-ray diffraction (XRD) analysis showed that most crystals changed from calcite to aragonite. X-ray energy dispersion spectroscopy (EDS) analysis showed that the weight percentage of Fe in the scale decreased by 9.81%. This shows that scale and corrosion on the heat exchange surface can be effectively improved under the action of an electric field.
Construction is one of the key parameters for social and economic growth for any nation, but it is also named as one of the major wastes generating process. However, it has sufficient potential to minimize or reduce any waste generation. Advance planning and monitoring start from the project till the end of construction can reduce waste generation up to a large extent. “Zero waste” is one of the most visionary approaches to overcome waste problems. In this research, the zero-waste approach is correlated for building construction work to assess the practical applications on a design and process throughout the life cycle. A state of zero waste can be reached by holistically implementing the revolutionary concept of prefabrication, demonstrability, circular economy, green rating tools and the principle of reducing, reuse and recycle. Further practices like smart waste audit, smart waste collection,high value mixed waste processing, and the collaborative platform further help towards the prime target of zero waste construction.
This paper proposes a new pneumatic mechanism for lime dosage in water treatment application. Conventionally, current water treatment system technologies utilising pump system, which requires scheduling maintenance of operation to avoid choke problem due to scaling development. The choke formation depends on the lime dosage concentration, which will be based on the time of operations. Technically, the pneumatic system uses such a hydraulic mechanism consisting of fluid, especially liquid oil, to operate, requiring higher maintenance costs. Based on these arguments, this research investigates the potential of replacing the pump system with an air pneumatic system for water treatment. For that reason, this study proposed a new design of pneumatic mechanism as the alternative solution for pump system. Several analyses have been performed from fluid mechanics to study the water treatment plant flow rate that could be competitive with the conventional pump system.
Focuses on applications and advantages of eco-friendly construction materials.
Discusses latest advances in landslide mitigation technologies.
Contains the selected contributions from the international conference ICCME 2020.
This experimental study aims at evaluating the performance of coal bottom ash (CBA) mortar after exposure to elevated temperatures. Two mortar mixes were prepared in which one was conventional natural sand (NS) based mortar and other mix contains CBA as 100% replacement of NS. The test specimens were cured for 28 days at ambient condition and then was heat treated at different elevated temperature (200, 400, 600 and 800 °C) using an electric controlled high-temperature furnace. The effect of elevated temperature on the mass loss, ultrasonic pulse velocity (UPV) and compressive strength of mortar specimens was evaluated after the high-temperature treatment. In addition, empirical equation derived from regression analysis was proposed to predict the residual mechanical strength of mortar incorporating CBA as fine aggregate at different elevated temperature. The test results signify that both mass and UPV decreases with increases in temperature, however, residual compressive strength of CBA mortar was better or comparable to NS mortar up to 400 °C, but above 400 °C; strength reduction rate in CBA mortar was higher than NS mortar.
The effect of electric field applied and Mg2+ doped on formation of calcium carbonatescale in circulating cooling water is investigated by using home-made experimental device, which can simulate the scaleof formationin local power plant. The results showthat high-voltage electrostatic fields and magnesium ions can inhibit scale growthin circulating cooling water. When the magnesium ion concentration is 4 mmol/L, the scale inhibition effect is the best under the action of the electric field (6 kV), and its scale inhibition rate can reach 44.56%. Meanwhile, some phenomenonare explained and confirmed by the results of first-principles calculations. The calculated shear modulus of aragonite is greater than that of calcite. This might be used to explain that aragonite is easier to adhere to the heat exchange surface. This is in good agreement with experimental results. Calcite has better anti-scaling property than aragonite. The crystal structure after physical water treatment is blunt, and the untreated crystal structure is sharp.
Selected technologies for centralised or decentralised drinking water softening were evaluated based on technical, economic, environmental and aesthetic indicators to identify the optimal treatment technology for a given setting. To achieve this, we demonstrated that a number of important indicators beyond hardness reduction and costs have to be included. All the evaluated centralised softening technologies could reduce water hardness to the target of 1.3 mmol/L at the Dutch drinking water treatment plant Beilen. CARIX® treatment and pellet softening with Ca(OH)2 resulted in a lower CCPP90 (0.25–0.30 mmol/L) than nanofiltration (0.30–0.35 mmol/L). Decentralised reverse osmosis had a water consumption of >100%, whereas decentralised cation exchange had a water consumption of 2.5%–4.5% which was comparable to centralised pellet softening (3.6%). Except for the electronic water conditioner that does not remove water hardness, the decentralised technologies were 7–10 times more expensive than the centralised technologies per m3 of softened water. The centralised softening technologies furthermore ensured supply of softened water to all customers in a water supply zone. Thus, in areas with hard water and limescale problems, investment in centralised softening at the local water utility is more optimal than widespread implementation of decentralised systems.
Green liquor scale is a recurring problem in most kraft mills. Several types of scale, e.g., pirssonite, calcite, sodium aluminosilicates, etc., have been identified in various green liquor scales. The mechanisms of formation and potential operational methods to control the formation of these scales is reviewed. Application: For mills, understanding ways to prevent scale formation will benefit the process area.
This paper presents a study of the mechanism of acoustic cavitation-generated erosion on metallic specimens coated with calcium carbonate (scale). Specimens were produced by scale deposition on steel substrates with different surface roughness, and then exposed to sonotrode-generated acoustic cavitation. The rate of scale removal was determined to be proportional to the pressure amplitude generated by the sonotrode. Descaling can also be intensified by reducing the substrate surface roughness. However, the scale destruction mechanism is largely dependent on the microstructure of the scale deposit, as local inhomogenities may intensify the erosion rate. Scale deposits can, depending on the hardness of its surface and substrate surface finish, either be eroded layer by layer, or by breakage of larger areas. Regardless of the exact descaling mechanism, the edge length-to-area ratio of descaled surfaces decreases with time, leading to a gradual reduction of descaling efficiency.
Ultrasonic technique was applied to remove the scaling compound CaCO3 as a pretreatment method in desalination process. Supersaturated solution of calcium carbonate was treated with an ultrasonic probe to precipitate CaCO3, followed by filtration to remove the precipitates. The fundamentals of nucleation, growth, crystal form and morphology of CaCO3 in the presence of the major seawater ions and ultrasound were investigated. Naked eye observation on induction time showed that ultrasound accelerates the nucleation by 60–85% though the major seawater ions delay the occurrence of nucleation up to 3 times longer. Continued ultrasound treatment after nucleation accelerates the growth rate by 2–5% only. Metastable vaterite with morphology of spherical aggregates constitutes ~ 90% of the obtained precipitates in most solution systems except F− and Na+, which favors calcite formation. Ultrasound treatment makes the aggregated crystals more fragile and breakable. As a pretreatment method, ultrasound technique not only accelerates the precipitation rate of CaCO3, but also has an effect in inhibiting the crystals growing into compact aggregates.
A biofilm is a layer of microorganisms contained in a matrix (slime layer), which forms on surfaces in contact with water. Their presence in drinking water pipe networks can be responsible for a wide range of water quality and operational problems.
To identify the bacterial isolates, obtained from water pipelines of kitchens, to evaluate the water quality & to study the biofilm producing capacity of the bacterial isolates from various sources.
A prospective study using water samples from aqua guard & pipelines to kitchens of S.C.B Medical College hostels.
Standard biochemical procedures for bacterial identification, multiple tube culture & MPN count to evaluate water quality & tissue culture plate (TCP) method for biofilm detection was followed.
STATA software version 9.2 from STATA Corporation, College station road, 90 Houston, Texas was used for statistical analysis.
One hundred eighty seven isolates were obtained from 45 water samples cultured. The isolates were Acinetobacter spp. (44), Pseudomonas spp.(41), Klebsiella spp.(36) & others . Biofilm was detected in (37) 19.78 % of the isolates (95% CI 30.08% -43.92%) including Acinetobacter spp.-10, Klebsiella spp. - 9, Pseudomonas spp. - 9, & others, majority (34) of which were from kitchen pipelines.
Water from pipeline sources was unsatisfactory for consumption as the MPN counts were > 10. Most of the biofilm producers were gram negative bacilli & Pseudomonas & Acinetobacter spp. were strong (4+) biofilm producers.
Safety and security are two important features of urban drinking-water distribution systems (UDWDS), worldwide, that are often compromised by a suite of physical, hydraulic, and chemical factors adversely impacting quality of potable water reaching consumer taps. Growth of scales and biofilm conglomerates (SBC) coupled with sorption of water chemicals and planktonic microorganisms by SBC has been increasingly recognized as underestimated contaminant sources in aging pipe networks of UDWDS. The main objective of this study was to provide an updated review of factors and processes associated with the increasing frequency of deteriorated finished water quality incidences as a result of SBC effects in UDWDS. This critical review integrated scattered knowledge on the effects of either pipe scales or pipe-anchored biofilm systems on contaminant destabilization and subsequent release into water. It was emphasized that little information exists on combined or concomitantly studied effects of SBC on finished water quality. Important synergistic SBC effects on finished water quality were identified as: (i) those promoting chemical release from pipe scales due to biofilm-induced alterations at the pipe surface/water interface, (ii) the synergistic SBC action on promoting increased release rates of pathogens or toxic chemicals into water, and (iii) the microbially enhanced corrosive phenomena on pipe scales and their constituents. Substantial room for improvement is anticipated for the water and global health research agenda by formulating innovative hypotheses and research designs that water authorities could benefit from as they strive towards further securing access to safe water in urban settings.
The physical water treatment (PWT) device is defined as a non-chemical method of water treatment utilized for the purpose of scale prevention or mitigation. Three different PWT devices, including permanent magnets, solenoid coil device, and high-voltage electrode, were used under various operating conditions. The present study proposed a bulk precipitation as the mechanism of the PWT and conducted a number of experimental tests to evaluate the performance of the PWT. The results of fouling resistances obtained in a heat transfer test section clearly demonstrated the benefit of the PWT when the PWT device was configured at an optimum condition. The results of SEM and X-ray diffraction methods were obtained to further examine the difference in scale crystal structures between the cases of no treatment and PWT. Furthermore, the surface tension of water samples was measured, and it was found that the PWT reduces the surface tension by approximately 8% under repeated treatment as in cooling-tower applications.
The working principle of the electrochemical softening process was studied at the laboratory scale in order to get a better understanding and to optimize the construction and the efficiency of industrial electrolysers. For this purpose pure calco carbonic synthetic waters with well defined hardness or distribution water from Paris were used. By using a local pH sensor, it was shown that the increase of the pH in the very vicinity of the cathode induces the precipitation of the calcium carbonate on the plate, in a first step under the effect of the oxygen reduction, and after that by water reduction associated with hydrogen evolution. The local pH can reach values greater than 10. The morphology and the crystal form (calcite, vaterite and/or aragonite) of the deposits were identified by scanning or transmission electron microscopy and by X ray diffraction. It was shown that, at the beginning of the treatment, vaterite and calcite crystals form a compact layer. In galvanostatic conditions, the decrease of the active area by deposition of the insulating scale leads to an increase of the local current density and then, to the transition towards the electrolytic water reduction regime. Adendritic growth of the calcium carbonate forming a porous layer through which hydrogen diffuses easily is observed.An investigation carried out on a model scale electrolyser showed the influence of various operating parameters such as current intensity, time of treatment etc. on the efficiency of the device. This electrochemical process is also able to eliminate partially various other species like magnesium.
I. G OLOGY OF CALCIUM CARBO ATE 1 by Jacques Geyssant 1. Features and characteristics of calcium carbonate 2 1. 1 Calcium carbonate - a special compound 2 1. 2 The crystal forms of calcium carbonate - mineralogy 9 2. The limestones - development and classification 15 2. 1 Sedimentation 16 2. 2 Diagenesis - from sediment to rock 23 2. 3 Classification of the limestones 24 2. 4 Metamorphism - from limestone to marble 26 2. 5 Carbonatites - extraordinary limestones 29 3. Limestone deposits 31 3. 1 Recognition of limestones 31 3. 2 Distribution on the Earth's surface 33 3. 3 Limestone deposits in the geological ages 36 3. 4 CaC0 cycle 42 3 3. 5 Industrially exploitable CaC0 deposits 3 44 53 II. TH C LT RAt HI TORY F LIME TONE by Johannes Rohleder 1. The history of chalk 55 2. Marble and limestone 69 2. 1 Quarrying stones 70 2. 2 Transport, organisation and trade 80 2. 3 The uses 97 137 III. CALCI M CARBOl\ATE - A MODER RESOURCE 1. The beginnings: Calcium carbonate in glazing putty and rubber 138 by Johannes Rohleder 1. 1 A chalk industry is born 139 1. 2 Rubber and glazing putty 142 1. 3 From chalk to calcium carbonate 156 2. Calcium carbonate - pigment and filler 160 by Eberhard Huwald 2. 1 Properties and effects of a filler 164 2. 2 Chalk, limestone, marble, pec - common features and differences 165 2. 2.
This chapter describes physical (nonchemical) water treatment (PWT) methods, which include permanent magnets, solenoid coils, radio frequency electric fields, high-voltage capacitance systems (i.e., electrostatic devices), and catalytic materials. The operating principle of the PWT is to produce colloidal particles of mineral ions in water, a process that is called bulk precipitation. In recirculating cooling water, the colloidal particles grow, resulting in particulate fouling (i.e., soft sludge coating) on a heat exchanger surface instead of precipitation fouling (i.e., hard deposit). Thus, if and when there is a sufficient shear force in a heat exchanger to remove the soft sludge coating, the PWT can keep the heat exchanger surface scale free.
Water, due to unique molecular properties, is a universal solvent for gases, solids, and liquids. Water intensive processes in the industry are subject to problems caused by the dissolved species, the most important being corrosion, because of dissolved oxygen, and scale formation. Other gases, such as CO2, SO2, and NOx, dissolved in water besides changing solution pH provide anions, which together with several of the cations present may form either ion pairs or insoluble salts that precipitate out provided that the saturation limit of the respective salts is exceeded. Nucleation and crystal growth may take place either in the bulk solution or on surfaces in contact with the supersaturated medium. Sedimentation of the bulk formed solids, in combination with electrostatically driven agglomeration, contributes to the formation of tenaciously adhering deposits on surfaces. Thermodynamic and kinetics analysis is necessary to understand scaling process.
Scaling is a serious problem in many industries. Scale formation is promoted by the presence of dissolved salts in a supersaturated solution. The precipitation of a crystalline substance from a solution onto the site of scale formation requires three simultaneous factors: supersaturation, nucleation, and adequate contact time. There are many factors influencing the scaling rate: supersaturation, retention time, hydrodynamic conditions such as velocity, pipe diameter and Reynolds number, surface roughness and material, and temperature. The scale formation can be inhibited by many types of additives, which have different efficiency on different scalants. The effectiveness of the inhibitors depends on various factors: contact time, temperature, solution pH, additive concentration, and structure. The Langmuir isotherm can be used effectively to predict the efficiency of scale inhibitors.
Results from a preliminary study into the effects of magnetic treatment on calcium carbonate formation are presented. A test rig was constructed to investigate the effect of orthogonally applied magnetic fields on solutions of calcium carbonate, with specific reference to changes in scale deposits formed. Results are compared with those of a reference system, identical in every way other than the application of the magnetic field. The results from this study indicated that magnetic treatment significantly influenced the deposition of calcium carbonate scale, under the controlled physico-chemical conditions employed. A scale reduction of 48% was recorded when the system was uncontrolled compared with negligible change when the system pH was controlled. In the uncontrolled system pH was shown to drop initially during magnetic treatment compared to that of the reference system. A pH regulated at 8 and 8.5 led to increased scaling and reaction rate but any effect magnetic treatment had on scale formation was apparently destroyed. It was concluded that pH plays an important role in the mechanism by which magnetic fields affect scaling in flowing systems.
While significant progress has been made in the mitigation of heat exchanger fouling, the challenge to reduce its impact on heat exchanger performance is still enormous. Many mitigation and cleaning techniques that have found their way into regular plant operation have been developed by an empirical trial-anderror approach. These antifouling strategies have few or even no links to academic research findings, since industry and academic research institutions have traditionally approached the problem of fouling from different aspects. To optimize the effectiveness of mitigation methods, which highly depends on the dominant fouling mechanisms and influential operating conditions, and to develop new approaches for fouling mitigation, closer collaboration between the two communities is essential. For the past 15 years, conferences on heat exchanger fouling have been held at bi-yearly intervals to facilitate innovative thinking and to explore new theoretical and practical approaches. These conferences have successfully provided a forum for experts from industry, academia, and government research centers from around theworld to present their latest research and technological developments in the areas of fouling mitigation and cleaning technologies. The meetings in San Luis Obispo (1995), Lucca (1997), Banff (1999), Davos (2001), Santa Fe (2003), Kloster Irsee (2005), Portugal and Tomar (2007) were organized by Engineering Conferences International. The 8th conference in this series was organized by the present authors under the auspices of EUROTHERM in Schladming, Austria, in June 2009. In total, 100 participants attended this meeting, presenting 81 papers/posters, which were the highest numbers in any meeting of this series to date. The following papers in this special issue of Heat Transfer Engineering have been selected from the contributions to the 2009 Fouling Conference in Schladming after a careful refereeing and revision process. The full e-proceedings of the 2009 conference as well as those from the previous conferences from 2003 until 2007 can be obtained free of charge from http://heatexchanger-fouling.com. They cover various aspects of heat exchanger fouling, along with updated state-of-the-art fouling mitigation and cleaning strategies. Their content is of significant value for researchers, plant operators, equipment manufacturers, chemical suppliers, and heat exchanger cleaning companies. This website also contains the actual information about the next conference in this series (Heat Exchanger Fouling and Cleaning IX), which is scheduled for June 5-10, 2011 on the beautiful island of Crete, Greece.
The effect of Zn and other metal ions, released by some physical water treatment devices, on the nucleation rate and crystal morphology of calcium carbonate was investigated. Zn in particular caused a substantial increase in induction time and induced the formation of calcium carbonate in the aragonite rather than the calcite form. These effects were quantified. A minimum Zn/Ca mass ratio of 0.06 x 10-3 was required for Zn to cause measurable effects. At [Ca] > .300 mg·dm-3 addition of Zn of up to 100μg·dm-3 had a negligible effect on nucleation rate and crystal morphology. Cu was found to be only half as effective as Zn while Mg required to be present at concentrations 1 000 times more than Zn to produce comparable effects. Colloidal Fe2O3 caused a decrease in induction time. The direct effect of Zn on scale reduction in laboratory tests amounted to about 77±6% and was achieved with 300 mg·dm-3 Ca solutions to which 200 μg·dm-3 Zn was added.
The objective of the present study was to examine the validity of a physical water treatment concept using a pulsed-power system, which was based on an induced electric field via Faraday's law. Heat transfer fouling tests were conducted and fouling resistance was measured over 820 h while maintaining the electric conductivity of circulating water at 2000 μmho/cm. The fouling resistance for the baseline case, which included a 20-μm filter, increased well over the industry standard allowance level, whereas the fouling resistance was remained essentially zero throughout the test period when the PPS was used in conjunction with a 20-μm filter. The test was repeated with water having an electric conductivity of 4000 μmho/cm and similar results were observed.
The objective of the present study was to investigate the validity of an electronic anti-fouling (EAF) technology through accelerated fouling tests. A plate-and-frame heat exchanger (with 20 stainless steel plates) was used for the tests, in which pressure drop across the heat exchanger, and the universal heat transfer coefficient were measured over a range of flow rates. In order to accelerate the rate of fouling, artificial hard water of 1000 ppm (as CaCO3) was used in the present study. The test results showed that the EAF technology could significantly reduce new scale deposits even in the accelerated fouling test, which was an extremely harsh fouling environment
The effect of underwater pulsed spark discharge on the precipitation of dissolved calcium ions was investigated in the present study. Water samples with different calcium hardness were prepared by continuous evaporation of tap water using a laboratory cooling tower. It was shown that the concentration of calcium ions dropped by 20–26% after 10-min plasma treatment, comparing with no drop for untreated cases. A laser particle counting method demonstrated that the total number of solid particles suspended in water increased by over 100% after the plasma treatment. The morphology and the crystal form of the particles were identified by both scanning electron microscopy and X-ray diffraction. Calcite with rhombohedron morphology was observed for plasma treated cases, comparing with the round structure observed for no-treatment cases. It was hypothesized that the main mechanisms for the plasma-assisted calcium carbonate precipitation might include electrolysis, local heating in the vicinity of plasma channel and a high electric field at the tip of plasma streamers, inducing structural changes in the electric double layer of hydrated ions.
A compact and low cost bench-top, pulsed electric field treatment system was designed and developed. The unit consisted of a high-voltage pulse generator (≤ 30 kV) and a treatment chamber with ≤ 148 ml capacity. Over the set-up voltage range of 4–26 kV, 30 pulses (with instant charge reversal) were applied to eight different enzyme solutions using a 0.3-cm electrode distance, a 13–87 kV/cm field, 0.5-Hz pulse frequency, 2-μs pulse width and 20 °C process temperature. For some enzymes, activities were reduced after the pulse treatments: lipase, glucose oxidase and heat-stable α-amylase exhibited a vast reduction of 70–85%; peroxidase and polyphenol oxidase showed a moderate 30–40% reduction whereas alkaline phosphatase only displayed a slight 5% reduction under the conditions employed. On the other hand, the enzyme activities of lysozyme and pepsin were increased under a certain range of voltages. Electric pulse profile (instant charge reversal) played a very important role in reducing the activities of various enzymes.
Process industry remains sceptical of antiscale magnetic treatment (AMT) despite its long history. Manufacturer's claims concerning AMT comprise: (a) a reduction in the amount of scale formed, (b) production of a less tenacious scale due to a change in its crystal morphology, (c) removal of existing scale, and (d) a retention of the antiscaling properties of the treated water for hours following treatment. Scientific research has both substantiated and refuted these claims, creating widespread controversy as to the credibility of this type of water conditioning. Positive results indicate effects on: (a) colloidal systems where aggregation is generally enhanced and (b) crystallisation where larger hydrophilic crystals, usually with modified crystal growth, are generated. Investigations have incorporated scaling kinetics, scale morphology, scale solubility, particle coagulation and corrosion. Effects have been reported for different scale-forming compounds and for various microscopic and macroscopic parameters in single-phase systems. AMT appears to be enhanced by prolonged or repeated magnetic exposure, and is more effective above a threshold magnetic field contact time and in flowing systems. Effects have been reported in treated waters up to 130 h after exposure has ceased. Industrial case studies indicate that the most successful implementations are in hot recirculating systems. Mechanisms presented to account for the observed effects comprise (a) intramolecular/intraionic interaction, (b) Lorentz force effects, (c) dissolution of contaminants, and (d) interfacial effects. The most plausible of these is the latter, in which the interaction of the magnetic field with the charged species present (ion clusters and crystallites) affects crystal nucleation and subsequent growth. The reported scale inhibition (and descaling) then occurs as a result of magnetically-produced hydrophilic discrete scale particles of substantially different size and crystal morphology to untreated systems, in which more adherent crystals are generated.
An innovative electromagnetic anti-fouling (EAF) technology was developed for heat transfer enhancement. A series of experiments with and without an EAF device were performed to find out the mechanism of heat transfer enhancement of the proposed technology. In the experiments, the variation of the fouling thermal resistance vs. time were measured and the scanning electron microscope (SEM) micrographs of the fouling layers were taken. The effects of EAF device at different temperature range were clarified.
The present study investigated the efficacy of a physical water treatment (PWT) technology using catalytic materials to mitigate mineral fouling in a heat exchanger. The fouling experiments were conducted using hard water with an electrical conductivity of 3600 μmhos/cm. The effects of three different velocities (0.3, 0.5, 0.8 m/s) on the performance of PWT using catalytic materials were examined. The present results showed that PWT decreased the fouling resistances by 17% to 38% depending on the flow velocity. Furthermore, SEM photographs revealed that treated cases produced a calcite form of scale, which can be easily detached by flow shear forces.
The present study investigated the feasibility of RF electrical fields in mitigating CaCO3 fouling in cooling water. Three different voltages and two frequencies were used for the RF electric fields produced directly in water with varying cold-side velocity. Artificial hard water was used. Fouling resistances for the PWT-treated cases decreased by 34–88% from the values for no-treatment cases, depending on the cold-side flow velocity. The results showed blunt crystal structures for the PWT-treated cases, while no-treatment cases had sharp and pointed crystal structures. The new PWT method using RF electric fields presents a valid tool to mitigate CaCO3 fouling in cooling water.
This paper provides a scientific explanation for the operating principle of the electronic anti-fouling (EAF) technology. The EAF technology produces an oscillating electric field via Faraday's law to provide necessary molecular agitation to dissolved mineral ions. Through improved collisions, they precipitate to insoluble mineral crystals, a process called “controlled precipitation.” Hence, the level of supersaturation of the hard water significantly decreases, and new scale deposits are prevented inside heat transfer equipment. © 1997 Elsevier Science Ltd
The present study introduces a new method in electronic descaling (ED) technology. In the proposed method, the ED apparatus consisted of a longitudinally positioned solenoid coil installed on an outer surface of a pipe. When electric current flows through the electric coils a magnetic field is generated whose direction is perpendicular to that of the flow direction. Experiments were performed at various Reynolds numbers. In order to monitor fouling at the heat transfer test section, the pressure drop across the test section and the overall heat transfer coefficient were measured as a function of time. The present study demonstrated an enhanced descaling effect of the longitudinally positioned solenoid coil while effectively inhibiting a formation of scales at slow flow conditions.
The present study conducted an investigation on the effect of high-frequency electric fields (HFEF) in calcium carbonate (CaCO(3)) scale formation on heated copper tube surfaces. Artificial hard water at varying CaCO(3) hardness was used. Calcium carbonate scales were formed on a heated copper tube surface, the fouling thermal resistance was calculated, and the calcium content of the deposited CaCO(3) scale was measured by an inductively coupled plasma mass spectroscopy (ICP-MS), and the cooling water was analyzed during the scaling process. No-treatment and HFEF-treatment cases were conducted and compared. The calcium content of the deposited scale dropped by 4-49% in HFEF-treatment case. The lower calcium content of the deposit corresponded to thinner deposits. Water analyses showed consistently lesser percentage drop in HFEF-treatment case primarily due to less fouling deposition. The asymptotic fouling thermal resistance in HFEF-treatment case had a maximum decrease of 88% (i.e., from 4.5 x 10(-4) to 5.4 x 10(-5) m(2)K/W).
Water is a major source for survival on this planet. Its conservation is therefore a priority. With the increase in demand, the supply needs to meet specific standards. Several purification techniques have been adopted to meet the standards. Magnetic separation is one purification technique that has been adapted from ore mining industries to anti-scale treatment of pipe lines to seeding magnetic flocculent. No reviews have come up in recent years on the water purification technique using magnetic assistance. The present article brings out a series of information on this water purification technique and explains different aspects of magnetism and magnetic materials for water purification.
Cooling water fouling-a brief review, fouling in heat Exchanger Equipment
- J G Knudsen
J.G. Knudsen, Cooling water fouling-a brief review, fouling in heat Exchanger
Equipment, 20th ASME/AICHE Heat Transfer Conference, Milwaukee, HTD -17,
1981, pp. 29-38.
A Study of Electronic Descaling Technology
- C F Fan
C.F. Fan, A Study of Electronic Descaling Technology, Ph.D Thesis, Drexel
University, Philadelphia, PA, 1997.
Mitigation of water fouling: technology status and challenges
- C B Panchal
- J G Knudsen
C.B. Panchal, J.G. Knudsen, Mitigation of water fouling: technology status and
challenges, Adv. Heat Transfer 31 (1998) 431-474.
Nonchemical Methods to Control Scale and Deposit Formation, Mineral Scales and Deposits, Scientific and Technological Approaches
- Y I Cho
- H S Kim
- Zahid Amjad
Y.I. Cho, H.S. Kim, Zahid Amjad, Kostas Demadis (Eds.), Nonchemical Methods to
Control Scale and Deposit Formation, Mineral Scales and Deposits, Scientific and
Technological Approaches, 2015, pp. 193-221 Chapter 9.
The effect of high intensity electric field pulses on eukaryotic cell membranes: fundamentals and applications
- U Zimmermann
U. Zimmermann, The effect of high intensity electric field pulses on eukaryotic cell
membranes: fundamentals and applications, in: U. Zimmermann, G.A. Neil (Eds.),
Electromanipulation of Cells, CRC Press, Boca Raton, 1996, pp. 1-106.
Pulsed electric fields in food Preservation, Handbook of Food Preservation Technology & Engineering
- R Shafiur
R. Shafiur, Pulsed electric fields in food Preservation, Handbook of Food
Preservation Technology & Engineering, (1999).
Water-Formed Scales and Deposits: Types, Characteristics, and Relevant Industries
- MacAdam J.
- Jarvis P.