Solids—liquid flow

Solid-liquid Flow of liquids in pipelines/filters Settling of particles in liquid (e.g. rust and sludge)... 

Chiu, C. L. and Seman, J. J., Head Loss in Spiral Solid-Liquid Flow in Pipes, Advances in Solid-Liquid Fhw in Pipes and Its Application, Ed. I. Zandi, Pergamon Press, 1971, p. 277. 

Even taking into account the different experimental conditions of the various workers and errors in their measurements, and the generally unstable nature of solid-liquid flow, equation 5.24 is completely inadequate as a design equation. 

An alternative approach to the representation of results for solid-liquid flow is to use the two-layer model which will be described in the following section. It will be seen that the coefficient of friction between the particles and the wall of the pipe is an important parameter in the model. It is suggested that its complete absence in equation 5.24 may be an important reason for the extent of the scatter. Unfortunately, it is a quantity which has been measured in only a very few investigations. It is interesting to note that the form of equation 5.19 was obtained by NEWITT et alP2) using a force balance similar to that... 

Z.ANDl. I. (cd) In Advances in Solid-Liquid Flow in Pipes and its Applications. Hydraulic Transport of Bulky Materials (Pergamon, Oxford, 1971). 

Virdung, T. and Rasmuson, A. (2008) Solid-liquid flow at dilute concentrations in an axially stirred vessel investigated using particle image velocimetry. Chem. Eng. Commun., 195 (1), 18-34. 

Wasp EJ, JP Kenny, RL Gandhi. Solid-Liquid Flow in Slurry Pipeline Transportation. Clausthal, Germany Trans-Tech, 1977. 

Rhodes, N., Pericleous, K. A., and Drake, S. N. Solid Liquid Flow 1 (1989) 35. The prediction of hydrocyclone performance with a mathematical model. 

E.J. Wasp, 3.P. Kenny, and R.L. Gandhi, Solid Liquid Flow Slurry Pipeline Transportation, Trans. Tech. Publications, Clausthal, Germany, 1977. 

Gas-solid and gas-solid-liquid flows are identified in Technology Vision 2020 The Chemical Industry as critical to developing advanced chemical reactors and separations. Solids handling is a critical technology for chemical manufacture. For companies such as DuPont and Dow Chemical Company, more than 50 percent of the products sold are in a solid/particulate form. This consortium was formed to develop technology to accurately model gas-solid transport in industrial applications. 

Langlois WE (1964) Slow Viscous Flow. Macmillan, New York Laux H (1998) Modeling of dilute and dense dispersed fluid-particle flow. Dr Ing Thesis, Norwegian University of Science and Technology, Trondheim, Norway Lawler MT, Lu P-C (1971) The role of lift in radial migration of particles in a pipe flow. In Zandi 1 (ed) Advances in Solid-Liquid Flow in Pipes and its Apphcations. Pergamon Press, Oxford, Chap 3, pp. 39-57 Lee SL (1987) Particle drag in a dilute turbulent two-phase suspension flow. Int J Multiphase Flow 13(2) 247-256... 

In this chapter, we will review the principles of acoustic measurement techniques and describe, in detail, acoustic flowmeters for solid/liquid and solid/gas pipe flows. Because field engineers who work with solid/liquid flows find it important to monitor liquid viscosity, we also describe the use of ultrasound to monitor. To conclude the chapter, we enumerate future sensor research needs. 

Solid/liquid flows are commonly found in industrial processes to avoid flow obstruction, nonintrusive flowmeters are generally preferred. Flowmeters based on ultrasonic techniques are ideal nonintrusive instruments because, in most applications, the ultrasonic transducers are simply clamped on the outside pipe wall. In this section, we describe two ultrasonic flowmeters based on the Doppler and cross-correlation methods. Both require an inherent flow tag thus both are directly applicable to solid/liquid flows because of the presence of solid particles. Both flowmeters measure mainly particle velocity liquid-phase velocity, if different from the particle velocity, is not determined. 

In principle, the ultrasonic techniques described for solid-liquid flow measurement can be applied to measure air flow rate and particle velocity. Direct measurement of air flow rate by measuring upstream and downstream transit times has been demonstrated. But, the Doppler and cross-correlation techniques have never been applied to solid/gas flow because the attenuation of ultrasound in the air is high. Recent developments have shown that high-frequency (0.5-MHz) air-coupled transducers can be built and 0.5-MI Iz ultrasound can be transmitted through air for a distance of at least 1 in. Thus, the cross-correlation technique should be applicable to monitoring of solid/gas flow. Here, we present a new cross-correlation technique that does not require transmission of ultrasonic waves through the solid/gas flow. The new technique detects chiefly the noise that interacts with the acoustic field established within the pipe wall. Because noise may be related to particle concentration, as we discussed earlier, the noise-modulated sound field in the pipe wall may contain flow information that is related to the variation in particle concentration. Therefore, crosscorrelation of the noise modulation may yield a velocity-dependent correlation function. 

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