An exploratory study of using external fluid loading on a vibrating tube for measuring suspended sediment concentration in water

Abstract

This paper presents an exploratory study of using external fluid loading on a vibrating tube for measuring the suspended sediment concentration (SSC) in bodies of water such as rivers and reservoirs. This new measuring concept provides an opportunity for an automated on-site monitoring of the conditions in a body of water by taking the fluid sample instantaneously in the area surrounding the vibrating tube. The physical properties of the fluid sample are those of the fluid that naturally flows around the tube, and are more representative of those of the water with SSC to be measured. The theoretical analysis presented in this paper shows that the resonance frequencies of an immersed vibrating tube change significantly with mass density variations that normally occur in bodies of water with suspended sediment. These changes are sensitive enough to have a possible 1% resolution of the measured fluid density. The signal processing issues are discussed, and a schematic of a conceptual measuring setup is proposed. Based on the theoretical analyses and other measurement issues presented in the paper, using the loading by external fluid on a vibrating tube is feasible for measuring the SSC in water bodies.

Continuous measurement of suspended sediment concentration: Technological advancement and future outlook

“…Hsu et al [35] found that the variations in dissolved solids concentration, water temperature, water pressure, flow rate, salinity, and debris on the walls of vibrating tube affect the resonance frequencies of immersed vibrating tubes considerably.…”

“…Hsu et al [35] presented a detailed theoretical analyses and measurement issues for practical application of vibrating tube technique and concluded that it is effective for SSC measurement in field applications. Bishwakarma and Stole [12] applied vibrating tubes technology for sediment monitoring in hydropower plant using a tool named ''Sediment Monitoring and Operation Tool for Hydro projects" (SMOOTH); the main sensor is a Coriolis Mass Flowmeter (CMF), that measures the density of flowing fluid through vibrating tubes (Fig.…”

Laboratory monitoring approaches for tailings settling and evaluation of flocculant and coagulant treatments

“…Currently, several monitoring practices have been developed for evaluation of settling behaviour of different suspensions, including bottle sampling, [8] pump sampling, [9] optical based on transmission [10] or scattering [11] of light, acoustic, [12,13] laser diffraction, [14] pressure difference, [15] spectral reflectance, [16] digital image and digital holographic image, [17][18][19] electrical properties, [20,21] vibrating tubes, [22] nuclear, [23,24] micro-tomography, [25] X-ray computer tomography (CT), [26] nuclear magnetic resonance (NMR), [27,28] and magnetic resonance imaging (MRI). [29][30][31] The pros and cons of these practices are reviewed elsewhere.…”