Ultrasonic Sensor for the Presence of Oily Contaminants in Water (original) (raw)
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Sensor Ultrasonico Para La Presencia De Contaminantes Oleosos en Agua
2012
The determination of the complex reflection coefficient of ultrasonic shear-waves at the solid-liquid interface is a technique employed for the measurement of the viscoelastic properties of liquids. An interesting property of the measurement technique is the very small penetration depth of the shear-waves into the liquid sample, which permits measurements with liquid films of some micrometers thick. This property, along with the adhesion of oily substances to surfaces, can be used for the detection of oily contaminants in water. In this work, the employment of the ultrasonic shear-wave reflection technique to the detection of oily contaminants in water is proposed and the theoretical and experimental concepts involved are discussed. Preliminary experimental results show the measurement technique can detect SAE 40 automotive oil in water in volume proportions less than 0.5%.
Chemical Engineering and Processing: Process Intensification, 2006
This paper presents an experimental study to investigate the suitability of thick-film ultrasonic transducers for composition measurements in heterogeneous mixtures. Following on from earlier developments [G. Meng, A.J. Jaworski, T. Dyakowski, J.M. Hale, N.M. White, Design and testing of a thick-film dual-modality sensor for composition measurements in heterogeneous mixtures, Meas. Sci. Technol. 16(4) (2005) 942-954], focused on the design and preliminary testing of the transducers for mixtures of vegetable oil and salty water, the current paper looks in more detail into their application to industrially relevant fluids, namely crude oil and process water, which are common in oil and gas extraction and petrochemical industries. The measurements are based on the time-of-flight of the ultrasonic pressure wave in order to obtain the speed of sound. The results, showing the variation of the speed of sound with the volume fraction of crude oil, for three different temperatures, are compared with five theoretical models available in the existing literature. It is shown that the models proposed by Urick [R.J. Urick, A sound velocity method for determining the compressibility of finely divided substances, J. Appl. Phys. 18 (1947) 983-987] and by Kuster and Toksöz [G.T. Kuster, M.N. Toksöz, Velocity and attenuation of seismic waves in two-phase media. Part I. Theoretical formulations, Geophysics 39 (1974) 587-606] provide a relatively accurate prediction for the speed of sound in the media studied. Interestingly, the model developed by Povey and co-workers [V.J. Pinfield, M.J.W. Povey, Thermal scattering must be accounted for in the determination of adiabatic compressibility, J. Phys. Chem. B 101 (1997) 1110-1112] only agrees with experiment when its thermal scattering features are neglected. Overall, the results obtained demonstrate that the slim-line and compact thick-film transducers can be considered as a viable means for the composition measurements in the process conditions.
A Method for the Measurement of Hydrodynamic Oil Films Using Ultrasonic Reflection
Tribology Letters, 2004
The measurement of the thickness of an oil film in a lubricated component is essential information for performance monitoring and control. In this work a new method for oil film thickness measurement, based on the reflection of ultrasound, is evaluated for use in fluid film journal bearing applications. An ultrasonic wave will be partially reflected when it strikes a thin layer between two solid media. The proportion of the wave reflected depends on the thickness of the layer and its acoustic properties. A simple quasi-static spring model shows how the reflection depends on the stiffness of the layer alone. This method has been first evaluated using flat plates separated by a film of oil, and then used in the measurement of oil films in a hydrodynamic journal bearing. A transducer is mounted on the outside of the journal and a pulse propagated through the shell. The pulse is reflected back at the oil film and received by the same transducer. The amplitude of the reflected wave is processed in the frequency domain. The spring model is then used to determine the oil film stiffness that can be readily converted to film thickness. Whilst the reflected amplitude of the wave is dependent on the frequency component, the measured film thickness is not; this indicates that the quasi-static assumption holds. Measurements of the lubricant film generated in a simple journal bearing have been taken over a range of loads and speeds. The results are compared with predictions from classical hydrodynamic lubrication theory. The technique has also been used to measure oil film thickness during transient loading events. The response time is rapid and film thickness variation due to step changes in load and oil feed pressure can be clearly observed.
Effect of temperature on the ultrasonic properties of oil-in-water emulsions
Colloids and Surfaces A-physicochemical and Engineering Aspects, 1998
The influence of temperature on the ultrasonic properties of oil-in-water emulsions was investigated. The ultrasonic velocity and attenuation coefficient of a series of corn oil-in-water emulsions with different disperse phase volume fractions (w=0 to 0.5) and mean droplet radii (r=0.1 to 0.5 mm) were measured as a function of temperature (5 to 50°C ). These measurements were in reasonable agreement with predictions made using ultrasonic scattering theory. The ultrasonic velocity of the emulsions was particularly sensitive to their composition, temperature and droplet size. Around 15°C, the ultrasonic velocity was fairly insensitive to oil concentration. Below this temperature, it increased with oil concentration, whilst above this temperature it decreased. The ultrasonic velocity increased with droplet size. The attenuation coefficient of the emulsions was much more sensitive to composition and droplet size, rather than temperature. It increased with oil concentration and decreased with temperature. The implications of these results for the use of ultrasound for determining the size distribution and concentration of droplets in emulsions are investigated.
An empirical method to estimate the viscosity of mineral oil by means of ultrasonic attenuation
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2000
This paper presents an empirical method for measuring the viscosity of mineral oil. In a built-in pipeline application, conventional ultrasonic methods using shear reflectance or rheological and acoustical phenomena may fail because of attenuated shear wave propagation and an unpredictable spreading loss caused by protective housings and comparable main flows. The empirical method utilizing longitudinal waves eliminates the unknown spreading loss from attenuation measurements on the object fluid by removing the normalized spreading loss per focal length with the measurement of a reference fluid of a known acoustic absorption coefficient. The ultrasonic attenuation of fresh water as the reference fluid and mineral oil as the object fluid were measured along with the sound speed and effective frequency. The empirical equation for the spreading loss in the reference fluid is determined by high-order polynomial fitting. To estimate the shear viscosity of the mineral oil, a linear fit is applied to the total loss difference between the two fluids, whose slope (the absorption coefficient) is combined with an assumed shear-to-volume viscosity relation. The empirical method predicted the viscosities of two types of the mineral oil with a maximum statistical uncertainty of 8.8% and a maximum systematic error of 12.5% compared with directly measured viscosity using a glass-type viscometer. The validity of this method was examined by comparison with the results from theoretical far-field spreading. in 2001, and the M.s. degree in electrical engineering and the Ph.d. degree in biomedical engineering from the University of southern california, los angeles, ca, in 2004 and 2005, respectively. He is currently a Transducer development Engineer at cameron Measurement systems, coraopolis, Pa, and a member of IEEE and the UFFc society. His interests include ultrasound transducer design and modeling.
Ultrasonic Investigation of Organic Fluids with Different Substituent Groups
Ultrasonic investigations have been made for the organic liquids at various temperatures. It is found that compressibility of these liquids increases with increase in temperature, in the temperature range studied. Linear relation between compressibility and temperature is observed in the liquids studied. Velocity of ultrasonic waves follows the reverse trend. Structural properties of these liquids have also been analyzed which revealed that velocity of ultrasonic waves in these liquids and hence their compressibility is found to be dependent on nature of substituent groups attached to the benzene ring. Experimental results indicate that heavy substitution of benzene ring results in increase in the ultrasonic wave velocity and hence decrease in compressibility of liquids. Similar acoustic study with aliphatic compounds, such as alcohols resulted in linear and sharp increase in compressibility.
Ultrasonic and Heat Treatment of Crude Oils
Energies, 2019
One of the methods of influence on rheological properties of heavy high-viscosity crude oils is ultrasonic treatment. Ultrasonic treatment allows reducing the viscosity of crude oil and, therefore, reducing the costs of its production and transportation. In this paper, the influence of ultrasonic treatment on the rheological characteristics of crude oil (sample No. 1 API = 29.1, sample No. 2 API = 15.9) was investigated. An experimental method was developed. Experimental studies were carried out using the Physica MCR 102 rheometer. The influence of the intensity and duration of ultrasonic treatment on the viscosity of the initial crude oils was studied for 24 h. In addition, the rheological characteristics of the treated oil were investigated after its natural cooling to 293 K. The results are compared with similar results for thermal heating.
ULTRASOUND MEASUREMENT OF THE CONTENT OF SOLID PARTICLES IN LIQUID MEDIA APPLIED TO OIL INDUSTRY
In oil industry, sand content in crude oils is commonly used as a parameter to determine the well deterioration level and to assess horizontal wells collapse risk. The sand content measurement is usually performed by a sand content meter device, which is based on a sieves system. This device requires a human operator to collect and analyze the crude oil samples. In order to allow a real time sand content monitoring in crude oil, this work presents a new ultrasonic technique to determine solid particle concentration in liquids. This technique consists in emitting an ultrasonic wave by an ultrasonic transducer and measuring the backscattered ultrasonic signals produced by sand particles. Therefore, the objective of this work is to develop a measurement cell based on the ultrasonic waves scattering to estimate the sand particles concentration in crude oil. The experimental observations were made with a measuring cell built for laboratory batch testing and continuous solid particles flow. Ultrasound transducers with central frequencies ranging from 5 and 10 M Hz in pulse-echo mode were used. Laboratory batch tests using sand particles ranging in size from 100 to 500 µm in diameter shown that there is a linear relationship between the volumetric fraction of particle and ultrasonic backscattered energy. The backscattered energy is proportional to the squared voltage measured from the receiving transducer. The echo signal mean energy at a given time window corresponds to the instantaneous flowing sand content through the cell. A micro-controlled feeder device was developed to perform tests on continuous solid particles flow. An analytical balance was used to calibrate the feeder to operate in the range from 2 to 20 mg/s, producing a water mixture ranging from 200 to 2000 ppm. Tests with continuous flow are in agreement with the expected results from the adopted methodology. A backscattered energy computational model based on a transducer impulse response and a plane piston model was developed to understand the experimental results. This model predicts the linear relationship between the backscattered energy and the particle concentration observed experimentally. The results demonstrate the technical feasibility of continuous flow measurements of sand in oil.