Online Measurement Of Viscosity Research Articles

On the use of submerged piezoelectric MFCs for dual viscosity sensing and energy harvesting

We demonstrate the potential of unimorph beams equipped with macro fiber composites to integrate viscosity sensing and energy harvesting functionalities into a single device. The viscosity sensing component involves measuring the quality factor and resonance frequency peak associated with the second out-of-plane mode of vibration. We showcase the suitability of the present sensing device for liquids of wide range of kinematic viscosities from 1 to 1543.5 cSt. Following the quality factor-based sensing approach, the sensor reached a sensitivity of S = −0.0019/cSt. The amplitude-based sensing mechanism demonstrated a sensitivity of S = −3.3 mV/cSt. The viscosities of motor oil and glycerin, determined using the generated calibration curves, are found in close agreement with those obtained from a conventional rotational viscometer. The proposed sensing device holds great promise for online viscosity measurement, particularly for high-viscosity fluids, simple design, ease of operation, and partial self-sensing capability, thanks to energy harvesting.

Continuous Manufacturing of a Polymer Stabilized Emulsion Monitored with Process Analytical Technology.

Moving from batch to continuous manufacturing (CM) requires implementation of process analytical technology (PAT), as it is crucial to monitor and control these processes. CM of semi-solids has been demonstrated but implementation of a broader range of PAT tools with in- or on-line process interfacing at the end of the CM line has not been demonstrated. The goal of this work was to continuously manufacture creams and to investigate whether in- and on-line measurement of viscosity, changes in the concentration of active pharmaceutical ingredient (API), and pH could be used to support optimization of a model cream product. Additionally, the torque of the mixers was assessed for determination of the physical properties of the cream. Two Raman probes with different probe optics were compared for characterization of the API concentration. The API concentration, amount of neutralizer, and mixing speed of the CM line were systematically varied. Both the PhAT probe with a larger sampling volume and immersion Raman probe with a smaller sampling volume could detect the step changes in the API concentration. The torque from the mixer was compared with the viscosity measurements, but the torque signal could not be correlated with the viscosity due to the dynamic nature of the polymer conformation and the time-dependency of this property. Adjustment of pH of the cream could be monitored with the current installation. The investigated PAT tools could be implemented into a continuous line and, further, be used to support the optimization of a model cream composition and related process parameters.

Combined dissolved oxygen tension and online viscosity measurements in shake flask cultivations via infrared fluorescent oxygen-sensitive nanoparticles.

Oxygen supply is one of the most critical process parameters in aerobic cultivations. To assure sufficient oxygen supply, shake flasks are usually used in combination with orbital shaking machines. In this study, a measurement technique for the dissolved oxygen tension (DOT) in shake flask cultures with viscosity changes is presented. The movement of the shaker table is monitored by means of a Hall effect sensor. For DOT measurements, infrared fluorescent oxygen-sensitive nanoparticles are added to the culture broth. The position of the rotating bulk liquid needs to be determined to assure measurements inside the liquid. The leading edge of the bulk liquid is detected based on the fluorescence signal intensity of the oxygen-sensitive nanoparticles. Furthermore, online information about the viscosity of the culture broth is acquired due to the detection of the position of the leading edge of the bulk liquid relative to the direction of the centrifugal force, as described by Sieben et al. (2019. Sci. Rep., 9, 8335). The DOT measurement is combined with a respiration activity monitoring system which allows for the determination of the oxygen transfer rate (OTR) in eight parallel shake flasks. Based on DOT and OTR, the volumetric oxygen transfer coefficient (kL a) is calculated during cultivation. The new system was successfully applied in cultivations of Escherichia coli, Bacillus licheniformis, and Xanthomonas campestris.

Development of an integrated RFID-IC technology for on-line viscosity measurements in enhanced oil recovery processes

This paper deals with on line viscosity measurements using integrated circuit technology, and is building on a previous paper on the use radio frequency identifier (RFID) technology for determining dielectric coefficients. It is asserted that the progress in RFID technology and integrated circuits, in particular in micro–electro–mechanical system (MEMS) makes it possible to combine them to perform physico-chemical property measurements using devices on centimeter scale. It can even be expected that these devices can be made increasingly smaller. An important property of interest is the viscosity, in this specific case, for the use of Arabic gum in enhanced oil recovery. Arabic gum, is an environmentally acceptable natural product. Natural-polymer solutions 1000 [ppm] are more viscous and therefore more efficient oil displacement agents. They require less invested exergy than non-viscosified water to recover oil. However, polymers, in particular environmentally acceptable natural-polymers (e.g., Guar–Arabic gum) available in large quantities in India and Sudan, are susceptible to microbial degradation. It is therefore important to monitor its quality at the injection and production side for real-time quality control. Natural-polymers based on plant products are promising EOR agents. They may have a lower environmental footprint because of the biodegradability. To provide a proof of concept, we use a state of the art acoustic wave sensor (AWS), which can determine acoustic viscosities. It is asserted that RFID technology can be used to record the acoustic wave signal (SenGenuity vismart acoustic wave Sensor AWS) to determine the viscosity at some distance (meters) away from the measurement device. A calibration with solutions of known viscosity behavior (i.e., Glycerol) can be used to relate the acoustic viscosity to the dynamic viscosity. We can calibrate the acoustic wave sensor using Guar–Arabic gum solutions to measurements with the Anton Paar viscometer (MCR-302). For the glycerol solution we also compare to reported literature data. The Newtonian viscosity measurements of the Paar density meter, and the literature values agree within a few percent. These favorable comparisons, are an important step in developing a methodology that allows cutting edge RFID-IC technology for real-time non-contact monitoring of viscosity degradation.

A novel design of flow structure model for online viscosity measurement

In industry, viscosity is widely used to assess the level of internal friction in a fluid in order to evaluate lubricant oil performance. Various sensing equipment has been developed to measure viscosity, either offline or online. However, most offline methods weaken the rheological behaviour of the fluid, resulting in inaccurate measurements. Online monitoring can overcome this limitation but viscosity measurements at real-time temperatures still cannot be directly converted to viscosities at the standard temperatures in ISO 3448. Consideration of the effect of temperature in transferring real-time viscosity measurement into the ISO standard presents a challenge. To bridge this research gap, this paper proposes a novel flow structure for online viscosity measurement by considering the effect of temperature. In order to eliminate the friction-heat effect and turbulent flow of the fluid, the structure parameters (such as flow diameter and heat transfer area) of the new viscosity sensing device are optimised by computational fluid dynamics (CFD) analysis using ANSYS/fluent simulations. The optimisation results demonstrate a linear relationship between the outlet, the inlet and the environmental temperatures of the designed flow structure under laminar flow. As a result, the outlet temperature can be controlled to obtain the viscosity-temperature characteristics of the lubricant oil using an online approach. In this way, the real-time viscosity measurement can be converted into the ISO standard to achieve effective online viscosity monitoring.

An Online Viscosity Measurement Method Based on the Electromechanical Impedance of a Piezoelectric Torsional Transducer

In this paper, we proposed an online viscosity measurement method based on the electromechanical impedance (EMI) of a piezoelectric torsional transducer. During testing, the contact torsional resonance of the cylindrical rod or host structure system is actuated and sensed by the ring array of shear mode piezoelectric patches. According to the quantitative electromechanical equivalent model we derived, the viscous damping from the contact fluid can be obtained by tracking the change of the piezoelectric impedance. A series of viscosity measurements was conducted on glycerol–water solutions of various concentrations, and the measurement results agree well with that given by standard laboratory viscometers. As the torsional vibration is a pure in-plane shear mode, which is more sensitive to the viscous damping and features a high quality factor, the proposed EMI-based measurement method is effective and promising for online viscosity measurement, especially for medium to high viscosity fluids.

Investigation of the use of electrolyte viscosity for online state-of-charge monitoring design in vanadium redox flow battery

In vanadium redox flow batteries, an accumulated imbalance of the states-of-charge between the two half-cell electrolytes caused by vanadium ion crossover and gassing side reactions can result in only one half-cell achieving 100% state-of-charge, which is referred to as capacity loss that needs to be corrected online. In order to implement rebalancing control, online states-of-charge have to be monitored. In this paper, the electrolyte viscosity and its use for online state-of-charge monitoring design are investigated. The study firstly measures the viscosities of both V2+/V3+ and VO2+/VO2+ redox couples in sulfuric acid as the negative and positive half-cell electrolytes at different states-of-charge and temperatures, followed by establishing an empirical neural network model that correlates the state-of-charge to viscosity and temperature. To overcome the limitation in online viscosity measurements, Darcy’s law describing the flow of a fluid through a porous medium is further introduced to link the electrolyte viscosity to the pressure drop across a porous medium where the electrolyte solutions flow through. Together with the neural network model, the state-of-charge can be eventually represented as a function of pressure, temperature and flow rate that are readily measurable online, and accordingly an online state-of-charge monitoring design is developed, which could be readily integrated into the online battery control system for automated electrolyte rebalance. Experimental validation is performed on a 15-cell stack system and the results demonstrate the feasibility of the proposed method.

A contact resonance viscometer based on the electromechanical impedance of a piezoelectric cantilever

In this work, we proposed a self-sensing contact resonance viscometer based on the electromechanical impedance of a piezoelectric bimorph cantilever whose free end is perpendicularly attached by a sensing slice. During measurement, the sensing slice is immersed into the fluid and excited in-plane vibration by the piezoelectric cantilever. The mechanical impedance from the fluid load is analyzed and the electromechanical impedance of the cantilever-fluid system is derived by using an equivalent circuit model. Then we track the electric impedance of piezoelectric bimorph to extract the dynamic viscosity of the testing fluid, based on the shift of the resonance frequency and the quality factor. Calibration experiments were carried out using glycerol-water solutions with different concentrations (10–2000cP). Finally, the viscosities of olive oil and silicon oil were measured using the calibrated curves, and the results coincided with that given by the standard viscometer. The proposed method is very promising for online viscosity measurement, especially for high-viscosity fluid, due to its high quality factor and self-sensing characteristic.

Online measurement of viscosity for biological systems in stirred tank bioreactors.

One of the most critical parameters in chemical and biochemical processes is the viscosity of the medium. Its impact on mixing, as well as on mass and energy transfer is substantial. An increase of viscosity with reaction time can be caused by the formation of biopolymers like xanthan or by filamentous growth of microorganisms. In either case the properties of fermentation broth are changing and frequently non-Newtonian behavior are observed, resulting in major challenges for the measurement and control of mixing and mass transfer. This study demonstrates a method for the online determination of the viscosity inside a stirred tank reactor. The presented method is based on online measurement of heat transfer capacity from the bulk medium to the jacket of the reactor. To prove the feasibility of the method, fermentations with the xanthan producing bacterium Xanthomonas campestris pv. campestris B100 as model system were performed. Excellent correlation between offline measured apparent viscosity and online determined heat transfer capacity were found. The developed tool should be applicable to any other process with formation of biopolymers and filamentous growth. Biotechnol. Bioeng. 2017;114: 990-997. © 2016 Wiley Periodicals, Inc.

Viscosity Measurement of Endothermic Fuels at Temperatures from 303 K to 673 K and Pressures up to 5.00 MPa

To meet the requirement of hydrocarbons online viscosity measurement at high temperatures and high pressures, two different methods are proposed in a two-capillary viscometer based on the Hagen–Poiseuille theory. Referenced flow method (RFM) measures the pressure drop, mass flux, and density ratios of the test and referenced fluid in a two-capillary system, and then calculates the test viscosity from the ratio relations regardless of the tube parameters. In another thermal expansion method (TEM), the fluid viscosity is obtained in a two-capillary process by measuring the pressure drop ratio, density ratio, and thermal expansion of a capillary tube. Note that mass flux and referenced fluid are no longer required in TEM. Pure n-dodecane and a binary mixture of n-heptane and n-octane were adopted respectively to validate the reliability and accuracy of the two methods. Results showed that the average absolute deviation (AAD) was lower than 0.75% and the maximum absolute deviation (MAD) was within 2.2%. Finally, viscosities of two endothermic fuels were obtained using the two-capillary viscometer at temperatures from (303.2 to 673.2) K and pressures up to 5.00 MPa. Accordingly, a viscosity relation formula as a function of temperature for two fuels was given within 4.2% deviation.

Capillary rheometry of a binary mixture polymer/CO2 in a single screw extruder

Processing bio-sourced polymers with supercritical fluids is a promising route towards new green engineering processes. Supercritical carbon dioxide (sc-CO2), is soluble in large quantities in molten polymers, where it acts as plasticizer and swelling agent. It is used, in blending or foaming of polymers, particle formation and polymerisation process.The process of hot-melt extrusion assisted by sc-CO2 allowed the development of an on-line viscosity measurement based on capillary rheometry. Applied to a bio-sourced polyamide, it was validated by comparison with a classic capillary rheometer. Both data sets were in good agreement.A pseudoplastic fluid behaviour was observed with a 30 % viscosity decrease from 46 to 32Pas at 5000s−1 and 220°C, upon addition of CO2. However, viscosity decreased to a plateau before reaching the thermodynamic solubility. The comparison with a model coupling solubility and flow allowed to identify the method limitations, which were attributed to the kinetics of dissolution and mixing. The higher the shear stress, the higher the amount of CO2 at which the viscosity plateau is reached. These measurements may quantify the impact of the CO2 on the rheology of the system but also of the efficiency of the mixing process in our experimental setup.

Experimental Investigation and Modeling of Permeability Impairment Mechanisms Due to Asphaltene Precipitation Under CO2 Injection Conditions

The injection of hydrocarbon gases/CO2 for enhanced oil recovery can promote asphaltene precipitation and consequently reservoir impairment, of which its impact is tremendous. In this work, the results of flow dynamic tests performed on sandstone as well as carbonate rocks were presented. The permeability reduction mechanisms were investigated during simultaneously injection of CO2 and recombined oil into core samples through a static mixer at reservoir conditions. The permeability impairment data was monitored from analysis of recorded pressure and online viscosity measurements during the experiments. Analysis of obtained results revealed that for both sandstone and carbonate rocks, surface deposition and pore plugging mechanisms participate simultaneously in reduction of permeability in primary injected pore volumes. Therefore, a new permeability reduction model is proposed that considers a combination of surface deposition and pore plugging mechanisms. The results of the new model are in good agreement with the obtained experimental data. The results of this work can be helpful for modeling of asphaltene deposition due to CO2 injection in petroleum reservoirs.

Using an in-line rotating torque transducer to study the rheological aspects of malaxed olive paste

A torque monitoring system was implemented on a malaxer machine prototype to investigate the rheological parameters of olive paste. In this study, the correlations between torque values and apparent viscosities were studied. The torque – viscosity correlation is important for defining an in-line parameter that can directly monitor during the kneading process, to determine when the paste is ready to progress to the next phase, to optimise the process, and to achieve higher quality products. During the malaxation process, the torque on the reel was measured using a rotating torque transducer. Viscosity measurements were performed using a Brookfield rotational viscosimeter. A model that correlates torque with the viscosity coefficient and flow behaviour index was defined. The good correlation between the off-line viscosity measurements and viscosity, as calculated by the model, confirms that the predicted mathematical model is able to produce a reliable assessment of the viscosity and that the torquemeter may represent an efficient device to obtain quite accurate on-line viscosity measurements.

The Research of Straight Pipe Viscometer

A straight pipe viscometer is proposed, which consists of the measuring sub-system and the data-acquisition and signal processing sub-system. The measuring sub-system include straight pipe, pressure transmitter, Coriolis flow-meter and slurry bump, and the data-acquisition and signal processing sub-system include single-chip processor, A/D converter, digital display, serial output port, drive circuit and so on. The measuring principle and working process of the straight pipe viscometer are analyzed. The measurement data and results are given and compared with test results of rotary viscometer in the same test conditions. The measuring accuracy is 3% at 5-150mPas, and the online measurement of viscosity is implemented.

Study on viscosity measurement using fiber Bragg grating micro-vibration

It is now ascertained that traditional electric sensors are vulnerable to electromagnetic interference when measuring viscosity. Here, we propose a new viscosity-sensitive structure based on the fiber Bragg grating (FBG) sensing principle and a micro-vibration measurement method. The symmetric micro-vibration motivation method is also described, and a mathematical model for compensational voltage and fluid viscosity is established. The probe amplitude, which is produced by reciprocating stimulation, is accessible by means of an FBG sensor mounted on an equal-strength beam. Viscosity can be therefore calculated using a demodulation technique based on linear edge filtering with long period grating. After performing a group of verifying tests, the sensor has been subsequently calibrated with a series of standard fluids to determine uncertain parameters in the mathematical model. The results of the experiment show that the relative measurement error was less than 2% when the viscosity ranged from 200 to 500 mPa s. The proposed architecture utilizes the characteristics of anti-interference, fast response speed, high resolution and compact structure of FBG, thereby offering a novel modality to achieve an online viscosity measurement.

Development of Polymer Extrusion Extruder for Evaluating with a Small Amount of Polymeric Material

Abstract We developed the extrusion system to evaluate the extrusion behavior such as the shear viscosity, which is one of basic properties, and the processability of mono/multilayer film with a small amount of polymeric material. In order to measure the shear viscosity, the gear pump, the return path and the pressure sensors were introduced into the extruder with intermeshing co-rotating twin screws. The viscosity could be evaluated on-line from the volumetric flow rate of molten polymer and the pressure drop in the return path before film processing. The capacity of gear pump, the shape and size of return path were optimized to evaluate the viscosity of polymeric material, which generally undergoes shear rate of 10 ∼ 1000 s−1 in the film processing. The apparatus for mono and multilayer film processing consisted of two extruders including the multichannel feedblock and T-die with the manifold and land section. The compact feedblock was designed to receive two feedstreams, so that the product can have two layers. We investigated the on-line viscosity measurement methodology and the processability, which is the neck-in phenomenon for monolayer film and the interface stability for multilayer film, using typical polymer material of 30 grams at once. The viscosity evaluated with our system corresponded with the result of commercial rheometer. It was also confirmed that the processability of mono and multilayer film could be evaluated quantitatively with our system.

A New Method for on-Line Measurement of Viscosity

Based on the increase type rotary encoder and the cantilever elastic element, a new kind of single cylinder rotary online viscosity sensor is designed, This article mainly introduces the principle of this sensor operation and the design calculation of the elastic element. And then further this paper shows how the finite-element method of the ANSYS is used to analyze the maximum deflection and the stress of the elastic element. Finally, the measurement error of is analyzed.

On-line monitoring of the viscosity of lubricating oils

An analysis of the features of variation and monitoring of the oil viscosity during tribosystem operation is presented. Methods and means for on-line monitoring of oil viscosity are reviewed, which allow on-line monitoring of the state of machinery and equipment. It is shown that the development of means for on-line measurement of viscosity based on the method applied under laboratory conditions does not meet the requirements for miniaturization and reliability of the diagnostic devices. To solve this problem, vibration methods of monitoring based on the application of tuning forks and microcantilevers are proposed. Among devices mounted directly into oil circulation lines, and, particularly, into lubricating systems for vehicles, acoustic devices have the most promise.

Online monitoring of the thermal degradation of POM during melt extrusion

AbstractBecause of its high stiffness, chemical resistance, and low viscosity, Poly (oxymethylene) (POM) is of high relevance for technical applications. The thermal degradation of POM during processing affects its final properties and decreases the long‐term stability. The degradation is indicated by the emission of formaldehyde (FA) gas. The aim of this study is to monitor the thermal degradation of POM online, during the melt extrusion in a co‐rotating twin screw extruder (TSE). The effect of the processing conditions on the thermal stabilisation of the POM is observed by FA emission and online viscosity measurements. The effect of processing conditions on the compounding of POM with two different FA scavengers is also studied. Fourier transform infrared (FTIR) spectroscopy is used for the online measurement of FA gas and acetyl acetone colour measurement for the offline characterisation. The online viscosity is measured by passing the melt through a slit die at constant volume flow rate. An enhanced thermal degradation is found with decreasing throughput and increasing screw speed. A good correlation between the online viscosity and offline FA measurement is observed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Fractionation, Characterization, and Study of the Emulsifying Properties of Corn Fiber Gum

Corn fiber gum (CFG) has been fractionated by hydrophobic interaction chromatography on Amberlite XAD-1180 resin using ionic, acidic, basic, and hydrophobic solvents of different polarities. Characterization, including determination of total carbohydrate, acidic sugar, and protein content, has been done for each fraction together with measurements of molar mass, polydispersity, radius of gyration, Mark-Houwink exponent, and intrinsic viscosity using multiangle laser light scattering and online viscosity measurements. Emulsification properties of all fractions in an oil-in-water emulsion system with 20:1 oil to gum ratio were studied by measuring turbidity over 14 days. The results indicate that CFG consists of different components differing in their molecular weights and carbohydrate and protein contents. The main fraction eluted with NaCl, although low in protein content, has the highest average molecular weight and was determined to be a better emulsifier than the other fractions. The unfractionated CFG, which contains different molecular species, is the best emulsifier.