Industrial Coolant Research Articles

Modified air-Fenton with MIL-88A for chemical oxygen demand treatment in used coolant oil.

Coolant oil from auto part manufacturing contains additives resulting in high chemical oxygen demand (COD) in wastewater. In this study, COD treatment of coolant oil was investigated in a metal-organic framework (MOF) with MIL-88A by a modified air-Fenton (MAF) process by varying synthetic coolant oil concentrations (1-5%), pH (3-9), air-flow rate (1-2 L/min), amount of MIL-88A (0.2-1.0g), and reaction time (30-180min). The results were analyzed using central composite design (CCD) and response surface methodology (RSM) using Minitab ver. 19. The characteristic MIL-88A was characterized by XRD that showed a spindle-like shape with 2θ at 10.2° and 13.0°. The FTIR spectrum revealed the vibrational frequencies at Fe-O (564cm-1), C-O (1391 and 1600cm-1), and C = O (1216 and 1710cm-1). The optimum treatment efficiency was studied from 30 CCD conditions in the presence of coolant oil (5%, COD ~ 132,000mg/L), pH (9), air flow rate (2 L/min), and MIL-88A (1g) within 177min. The results obtained from the experiment and the COD prediction were found to be 92.64% and 93.45%, respectively. The main mechanism of iron(III) in MIL-88A is proposed to be the production of hydroxyl radical (·OH) that oxidizes the organic matter in the coolant oil. Moreover, the MAF process was applied to the used industrial coolant oil and was found to be 62.59% efficient.

Photocatalytic degradation of reactive dyes using natural photo-smart pigment-A novel approach for waste water re-usability.

The present study is aimed at an efficient photocatalytic degradation of industrially important reactive dyes using phycocyanin extract as aphotocatalyst. The percentage of dye degradation was evidenced by aUV-visible spectrophotometer and FT-IR analysis. The degraded water was checked for its complete degradation by varying pH from 3 to 12. Furthermore, the degraded water was also analyzed for water quality parameters and was found to meet industrial wastewater standards. The calculated irrigation parameters like magnesium hazard ratio, soluble sodium percentage, and Kelly's ratio of degraded water were within the permissible limits, which enables its reusability in irrigation, aquaculture, as industrial coolants, and domestic applications. The calculated correlation matrix shows that the metal influences various macro-, micro-, and non-essential elements. These results suggest that the non-essential element lead can be effectively reduced by increasing all the other micronutrients and macronutrients under study except sodium metal.

Ti3C2Tx MXene nanofluids with enhanced thermal conductivity

Recent advances in nanotechnology have led researchers to investigate various approaches to the development of nanofluids with enhanced thermal conductivities that can replace conventional industrial coolants. Of particular interest have been MXene based nanofluids. The current investigation focuses on MXene/water and MXene/ethylene-glycol/water nanofluids with particle concentrations ranging from 0.1 to 0.5 wt% of MXene. The results of this investigation found as much as a 30.6% improvement in the effective thermal conductivity of the 0.5 wt% MXene/water nanofluid compared to the pure water base fluid. In addition, an improvement of 27.3% in the effective thermal conductivity was observed in MXene/ethylene-glycol/water nanofluid. MXene was found to provide superior enhancement in the effective thermal conductivity when compared with other particles, such as metal, metal oxide, and graphene, both in DI water and in ethylene glycol. In addition, MXene did not significantly increase the viscosity as is typically the case for other nanosuspensions containing carbon nano materials, e.g. nanotubes, graphene. The physical properties indicated that MXene based nanofluids present a number of very attractive thermophysical properties for application as industrial coolants.

Mapping relationships between cation-F bonds and the heat capacity, thermal conductivity, viscosity of molten NaF-BeF2

Molten NaF-BeF2 has been proposed as one of the potential solvents and coolants for the Generation IV nuclear reactor, due to the lower price and satisfactory neutron capture cross-section. To gain comprehensive information on the structures and thermophysical properties of molten NaF-BeF2, FPMD simulations are applied to study its bond lengths, bond angles, and polyhedrons as well as the densities, specific heat capacity, thermal conductivities, and viscosities in the temperature range of 673–1073 K. These results show that 4- and 6-fold coordination structures of Be-F and Na-F are dominant in molten NaF-BeF2, respectively, and the diversity of Na-F polyhedral clusters originates from the inferior strength and stability of Na-F bonds. Besides, the Be-F bond is 6 times more stable than Na-F, whose strong stability leads to the large specific heat capacity (>1.5 J g−1 K−1) of NaF-BeF2, thereby the high ability of heat storage. Furthermore, the mapping relationship between the viscosity and structure of molten NaF-BeF2 are revealed, where the Na-F bond plays a key role on reducing viscosity (<5 cP above 873 K) that makes its use as an industrial coolant possible.

Research Progress of Ionic Liquids as Lubricants.

Emerging ionic liquid lubricants were discovered only 20 years ago. The superior performance of ionic liquids over traditional lubricating fluids have been reviewed, including low-temperature fluidity, viscosity–temperature properties, thermal oxidation stability, ultralow volatility, incompressibility, electrical conductivity, friction coefficient under elastohydrodynamic lubrication conditions, friction reduction and antiwear performance under boundary lubrication conditions, environmental friendliness, etc. The applications where ionic liquids are superior to traditional lubricant fluids are presented, including hydrogen compressor lubricating fluids and liquid pistons, oxygen compressor lubricating fluids, hydraulic fluids, space lubricants, vehicle engine oils, industrial gear oils, metalworking fluids, industrial coolant, micro/nano electromechanical system applications, electrical conductive lubricants, etc. The ability of ionic liquids to replace ZDDP, a key additive of lubricating oil, is introduced. The future development prospects of ionic liquid lubricants are analyzed.

Numerical Prediction of Heat Transfer of Commercial R12 Coolant Through Different Cross-Section Microchannels of Same Hydraulic Diameter

Microchannels are the next step for current heat exchangers and probably the most effective cooling technique for recent miniaturized electronic components. Five different shapes of pipes (rectangular, circular, triangular, semi-circular &amp; trapezoidal) of same hydraulic diameter are taken into consideration for this numerical investigation. One industrial coolant namely R12 is passed through the above-mentioned channels. This numerical investigation seeks to find out which section shape is the best suitable one for two phase heat transfer phenomenon. The present work is validated with the experimental work of Liu, Lee&amp; Garimela where water is used as a coolant and passed through a rectangular channel and the numerical simulation is carried out with the help of commercial Ansys software. The current investigation aims to link the applicability of commercial coolants in the field of microchip cooling. This study will help electronics cooling industries by pinpointing the enhanced heat transfer phenomenon through microchannel where microchannel geometry and coolant both play a crucial role apart from the material itself.

Toxicity drives facilitation between 4 bacterial species

Competition between microbes is extremely common, with many investing in mechanisms to harm other strains and species. Yet positive interactions between species have also been documented. What makes species help or harm each other is currently unclear. Here, we studied the interactions between 4 bacterial species capable of degrading metal working fluids (MWF), an industrial coolant and lubricant, which contains growth substrates as well as toxic biocides. We were surprised to find only positive or neutral interactions between the 4 species. Using mathematical modeling and further experiments, we show that positive interactions in this community were likely due to the toxicity of MWF, whereby each species' detoxification benefited the others by facilitating their survival, such that they could grow and degrade MWF better when together. The addition of nutrients, the reduction of toxicity, or the addition of more species instead resulted in competitive behavior. Our work provides support to the stress gradient hypothesis by showing how harsh, toxic environments can strongly favor facilitation between microbial species and mask underlying competitive interactions.

Experimental Convection Heat Transfer Analysis of a Nano-Enhanced Industrial Coolant.

Convection heat transfer coefficients and pressure drops of four functionalized graphene nanoplatelet nanofluids based on the commercial coolant Havoline® XLC Pre-mixed 50/50 were experimentally determined to assess its thermal performance. The potential heat transfer enhancement produced by nanofluids could play an important role in increasing the efficiency of cooling systems. Particularly in wind power, the increasing size of the wind turbines, up to 10 MW nowadays, requires sophisticated liquid cooling systems to keep the nominal temperature conditions and protect the components from temperature degradation and hazardous environment in off-shore wind parks. The effect of nanoadditive loading, temperature and Reynolds number in convection heat transfer coefficients and pressure drops is discussed. A dimensionless analysis of the results is carried out and empirical correlations for the Nusselt number and Darcy friction factor are proposed. A maximum enhancement in the convection heat transfer coefficient of 7% was found for the nanofluid with nanoadditive loading of 0.25 wt %. Contrarily, no enhancement was found for the nanofluids of higher functionalized graphene nanoplatelet mass fraction.

Functionalized graphene nanoplatelet nanofluids based on a commercial industrial antifreeze for the thermal performance enhancement of wind turbines

The overheating of mechanical and electrical components in generators of wind turbines considerably reduces their overall performance. Consequently, their cooling systems usually need to dissipate large amounts of heat, leading to high electrical energy consumptions. These systems habitually use commercial industrial coolants as working fluids in order to avoid freezing at low temperatures and corrosion of mechanisms. Dispersions of graphene nanoplatelets are expected to enhance the thermal conductivity of glycolated water-based fluids, but scarce studies were reported in the literature using commercial industrial antifreezes as base fluid.In this study a comprehensive thermophysical characterization of different loaded polycarboxylate chemically modified graphene nanoplatelet nanofluids (0.25, 0.50, 0.75 and 1.0 wt%) based on a commercial coolant, Havoline® XLC Premixed 50/50, extensively employed in cooling systems of wind turbines, was carried out. Firstly, with the purpose of achieving long-term stabilities, it was found the optimum sodium dodecyl benzene sulphonate concentration, 0.125 wt%, through zeta potential and dynamic light scattering measurements, finding no substantial alteration of the original pH value. Densities were measured by pycnometry, heat capacities by differential scanning calorimetry and thermal conductivities by transient hot wire technique, in the temperature range from (293.15 to 343.15) K. Moreover, rheological behaviour was experimentally determined by means of a rotational rheometer with cone-plate geometry at temperatures from 293.15 to 323.15 K. Thermal conductivity enhancements reaching 7.3% and dynamic viscosity increases up to 20% were found. Potential heat transfer performance capabilities and pumping power consumptions in both laminar and turbulent flow conditions were investigated through the analysis of equivalent ratios derived from the experimentally measured properties, optimal concentrations for both regimes being determined.

Characterization of Industrial Coolant Fluids and Continuous Ageing Monitoring by Wireless Node-Enabled Fiber Optic Sensors.

Environmentally robust chemical sensors for monitoring industrial processes or infrastructures are lately becoming important devices in industry. Low complexity and wireless enabled characteristics can offer the required flexibility for sensor deployment in adaptable sensing networks for continuous monitoring and management of industrial assets. Here are presented the design, development and operation of a class of low cost photonic sensors for monitoring the ageing process and the operational characteristics of coolant fluids used in an industrial heavy machinery infrastructure. The chemical, physical and spectroscopic characteristics of specific industrial-grade coolant fluids were analyzed along their entire life cycle range, and proper parameters for their efficient monitoring were identified. Based on multimode polymer or silica optical fibers, wide range (3–11) pH sensors were developed by employing sol-gel derived pH sensitive coatings. The performances of the developed sensors were characterized and compared, towards their coolants’ ageing monitoring capability, proving their efficiency in such a demanding application scenario and harsh industrial environment. The operating characteristics of this type of sensors allowed their integration in an autonomous wireless sensing node, thus enabling the future use of the demonstrated platform in wireless sensor networks for a variety of industrial and environmental monitoring applications.

Potentiometric Online Detection of Aromatic Hydrocarbons in Aqueous Phase Using Carbon Nanotube-Based Sensors

Surfaces made of entangled networks of single-walled carbon nanotubes (SWCNTs) display a strong adsorption affinity for aromatic hydrocarbons. Adsorption of these compounds onto the walls of SWCNTs changes the electrical characteristics of the SWCNT-solution interface. Using these features, we have developed a potentiometric sensor to detect neutral aromatic species. Specifically, we can detect online aromatic hydrocarbons in industrial coolant water. Our chromatographic results confirm the adsorption of toluene onto the walls of carbon nanotubes, and our impedance spectroscopy data show the change in the double layer capacitance of the carbon nanotube-solution interface upon addition of toluene, thus confirming the proposed sensing mechanism. The sensor showed a toluene concentration dependent EMF response that follows the shape of an adsorption isotherm and displayed an immediate response to the presence of toluene with a detection limit of 2.1 ppm. The sensor does not respond to other nonaromatic hydrocarbons that may coexist with aromatic hydrocarbons in water. It shows a qualitative sensitivity and selectivity of 100% and 83%, respectively, which confirms its ability to detect aromatic hydrocarbons in aqueous solutions. The sensor showed an excellent ability to immediately detect the presence of toluene in actual coolant water. Its operational characteristics, including its fast response, low cost, portability, and easy use in online industrial applications, improve those of current chromatographic or spectroscopic techniques.

Pollution of coastal seas

Pollution of various environments is a consequence of population growth and industrialisation. Coastal seas form part of marine environment and are very rich in minerals, crude oil, fishes etc. They are also being used for disposal of wastes from cities. Various types of wastes, if not properly treated, would cause serious pollution of these shallow seas endangering marine life and spoiling recreational facilities. Different polluting agents like sewage, chemicals, industrial coolants etc. and their effects in the coastal seas are discussed with a historical background.

Rapid assessments of emulsifier levels in industrial coolants

A technique for assessing the levels of emulsifiers in industrial coolants on the basis of the dilution required to achieve critical micelle concentration is described. The technique was used to compare fungally degraded coolant samples with appropriate control samples and results were obtained which provided evidence of emulsifier depletion in the degraded samples.

工業用冷却水としての海水

工業用冷却水としての海水