Modelling ultrasonic sensor for gas bubble profiles characterization of chemical column

Rahiman, Mohd Hafiz Fazalul; Rahim, Ruzairi Abdul; Rahim, Herlina Abdul; Ayob, Nor Muzakkir Nor; Mohamad, Elmy Johana; Zakaria, Zulkarnay

doi:10.1016/j.snb.2013.04.062

Cited by 20 publications

(8 citation statements)

References 9 publications

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“…So far, there have been many technologies to achieve chemical sensing, including acoustic 2 , 3 , optical 4 – 6 , pure chemical 7 and electromagnetic 8 , 9 detection. In ultrasonic sensors, the transmitter sends a discontinuous signal to the liquid, and then the echo signal is detected to obtain information including time of flight, signal amplitude, and further determines the property of sample based on the theory of Hale 10 .…”

Section: Introductionmentioning

confidence: 99%

Multi-Band Sensing for Dielectric Property of Chemicals Using Metamaterial Integrated Microfluidic Sensor

Zhou

Yang

et al. 2018

Sci Rep

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The growth of the chemical industry has brought tremendous challenges to chemical sensing technology. Chemical sensors based on metamaterials have great potential because of their label-free and non-destructive characteristics. However, metamaterials applied in chemical sensing have mainly been investigated from the measurement of sample concentration or the determination of the dielectric properties at a fixed frequency. Here we present a metamaterial integrated microfluidic (MIM) sensor for the multi-band sensing for dielectric property of chemicals, which is promising for the identification of chemicals. The MIM sensor mainly consists of multiple pair of high sensitive symmetrical double split-ring resonators (DSRRs) and meandering microfluidic channels with a capacity of only 4 μL. A dielectric model has been innovatively established and experimentally verified to accurately estimate the complex permittivity and thus realize the multi-band sensing of dielectric property of chemicals. With the increase in the number of resonators in the sensor, a dielectric spectrum like curve could be obtained for more detailed dielectric information. This work delivers a miniaturized, reusable, label-free and non-destructive metamaterial-microfluidic solution and paves a way of the multi-band sensing for dielectric property of chemicals.

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Section: Introductionmentioning

confidence: 99%

Multi-Band Sensing for Dielectric Property of Chemicals Using Metamaterial Integrated Microfluidic Sensor

Zhou

Yang

et al. 2018

Sci Rep

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“…As shown in Figure 4, attenuation of ultrasonic waves occurs during propagation through a medium, and this procession can be described by the following equation:p=p0expfalse(−αLfalse) α=−1Llnpp0 where, p and p 0 are the acoustic pressure after the propagation distance L , and the initial incident acoustic pressure, respectively, and α refers to the attenuation coefficient of sound pressure. At room temperature, attenuation coefficient in water α equals 25.3 × 10 −15 f 2 , and its unit is Np/m [22]. The attenuation coefficient α is proportional to the square of the excitation frequency f .…”

Section: Working Principles and Theoretical Backgroundmentioning

confidence: 99%

“…For examples, ERT technique coupled with differential pressure measurement to [19,20], and the ECT technique coupled with the optical measurement method [16]. Ultrasonic tomography (UT) can also be used to monitor the gas holdup in bubble columns [21,22] and other types of chemical mixtures, such as liquid-liquid flow patterns [23,24]. The working principle of ultrasonic tomography (UT) is based on the interaction between the ultrasonic wave and the medium measured.…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic Transmission Tomography Sensor Design for Bubble Identification in Gas-Liquid Bubble Column Reactors

Cao

et al. 2018

Sensors

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Scientists require methods to monitor the distribution of gas bubbles in gas-liquid bubble column reactors. One non-destructive method that can potential satisfy this requirement in industrial situations is ultrasonic transmission tomography (UTT). In this paper, an ultrasonic transmission tomography sensor is designed for measuring bubble distribution in a reactor. Factors that influence the transducer design include transmission energy loss, the resonance characteristics and vibration modes of the transducer, and diffusion angles of the transducers, which are discussed. For practical application, it was found that an excitation frequency of 300 kHz could identify the location and size of gas bubbles. The vibration mode and diffusion also directly affect the quality of the imaging. The geometric parameters of the transducer (a cylinder transducer with a 10 mm diameter and 6.7 mm thickness) are designed to achieve the performance requirements. A UTT system, based on these parameters, was built in order to verify the effectiveness of the designed ultrasonic transducer array. A Sector-diffusion-matrix based Linear Back Projection (SLBP) was used to reconstruct the gas/liquid two-phase flow from the obtained measurements. Two other image processing methods, based on SLBP algorithm named SLBP-HR (SLBP-Hybrid Reconstruction) and SLBP-ATF (SLBP-Adaptive Threshold Filtering), were introduced, and the imaging results are presented. The imaging results indicate that a gas bubble with a 3 mm radius can be identified from reconstructed images, and that three different flow patterns, namely, single gas bubble, double gas bubble with different diameters, and eccentric flow, can be identified from reconstructed images. This demonstrates that the designed UTT sensor can effectively measure bubble distribution in gas-liquid bubble column reactors.

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“…33, No. 4) in the bubble diameter, as illustrated by the computed results through sound field numerical simulation [10,23]. However, for the situation with multiple bubbles in the pipe, the ultrasonic field distribution is also complex and worth exploring.…”

Section: Simulation Of the Different Bubble Sizes And Distributionmentioning

confidence: 99%

“…The dispersed phase concentration plays an important role in the amplitude of the transmission ultrasound [8], and the ultrasonic attenuation changed with regularity when the gas flow rate increased [9]. Rahiman et al introduced a mathematical model to explain the influence of a single gas bubble on ultrasound propagation, concluding that the ultrasonic attenuation increased with increases in the bubble diameter [10]. Supardan et al reported that in a rectangular bubble column, the ultrasonic attenuation has an approximate linear relationship with gas holdup in a certain range [11].…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic method for measuring the gas holdup of gas-liquid bubbly flow in a small-diameter pipe

Gong

Zhao

Zhai

et al. 2016

Korean J. Chem. Eng.

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Based on ultrasonic sound pressure attenuation, the ultrasonic pulse transmission method is proposed for measuring gas holdup in gas-liquid two-phase bubbly flows. Two ultrasonic transducers are positioned on opposite sides of a vertical upward pipe with an inner diameter of 20 mm. To obtain the relationship between ultrasonic attenuation and gas holdup, the mean value of the first pulse sequence of ultrasonic signals is first extracted as the measured signal. We used the quick closing valve method to obtain the gas holdup as the set value. Second, the relationship between the gas holdup and measured ultrasonic signals was established. The experiment result shows that the ultrasonic attenuation rate is significantly different at low and high gas holdups, as indicated by the bubble size images with a high-speed camera. We also investigated the ultrasonic field distribution using numerical simulation. The bubble size has an important effect on the ultrasonic attenuation coefficient, which provides a further physical explanation and reference for the experimental phenomena.

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Modelling ultrasonic sensor for gas bubble profiles characterization of chemical column

Cited by 20 publications

References 9 publications

Multi-Band Sensing for Dielectric Property of Chemicals Using Metamaterial Integrated Microfluidic Sensor

Multi-Band Sensing for Dielectric Property of Chemicals Using Metamaterial Integrated Microfluidic Sensor

Ultrasonic Transmission Tomography Sensor Design for Bubble Identification in Gas-Liquid Bubble Column Reactors

Ultrasonic method for measuring the gas holdup of gas-liquid bubbly flow in a small-diameter pipe

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