Yamin Xu

Signal Processing In Transmission Fluctuation Spectrometry With Band‐Pass Filter

Transmission fluctuation spectrometry is a recently‐developed method for particle size analysis, in which both the particle size distribution and particle concentration can be obtained simultaneously. This work presents a new technique of data processing of the fluctuating transmission signal. The 1st order band pass filter is employed to improve the resolution of the measurement. The analytical expression is obtained on the basis of the layer model. Numerical results and simulated results are given to make a comparison.

Particle analysis on concentrated particle suspensions by transmission fluctuation spectrometry with band-pass filters: part 1. Simulation

Transmission fluctuation spectrometry (TFS), as a new method of online and real-time particle analysis developed in recent years, can measure the particle size distribution and particle concentration simultaneously. In this work, TFS with band-pass filters is studied by numerical simulation in which the particle concentration varies in a large dynamic range. The results of the simulations show that the transmission fluctuation spectrum is related to the particle concentration of the suspension, the pathlength of the light beam within the particle system and the beam-to-particle diameter ratio. Empirical expressions to correct the effects of particle overlapping on the transmission fluctuation spectrum are obtained, which are found to be experimentally validated.

Particle analysis on concentrated particle suspensions by transmission fluctuation spectrometry with band-pass filters: part 2. Experimental results

Transmission fluctuation spectrometry (TFS), as a new method of online and real-time particle analysis developed in recent years, can measure the particle size distribution and particle concentration simultaneously. In the preceding paper, high concentration effects on the TFS using band-pass filters were investigated by numerical simulation, and empirical expressions to correct the effects were obtained. This paper presents a study on the TFS measurements in which the particle concentration varies in a very wide dynamic range. Finally, reasonable results on both the particle size distribution and particle concentration are obtained by introducing empirical corrections into the inversion algorithm.

High concentration effects of transmission fluctuation spectrometry with temporal correlation

Transmission fluctuation spectrometry (TFS) with temporal or spatial correlation is a recently-developed method for real-time, online/inline particle analysis in two-phase flows, whereby the particle size distribution (PSD) and particle concentration can be measured simultaneously. On the basis of a layer model and the assumption of geometrical ray propagation, an analytical expression of the transmission fluctuation spectrum can be obtained. It is found that the measurement matches the theory very well as long as the particle concentration is low enough. However, as the particle concentration increases, the measured transmission fluctuation spectrum deviates gradually from the theory, which is a result from the high concentration effects. The high concentration effects include those from particle overlapping and the monolayer structure. In this presentation, the high concentration effects are studied with numerical simulation. As a result, the empirical expressions for the correction of the high concentration effects are obtained.

EFFECTS OF PARTICLE OVERLAPPING ON TRANSMISSION FLUCTUATION SPECTROMETRY WITH TEMPORAL CORRELATION

Transmission fluctuation spectrometry with temporal or spatial correlation is being developed as a new method for particle size analysis, in which the particle size distribution and particle concentration can be measured simultaneously. Based on the assumption of low particle concentrations, an analytical expression of the transmission fluctuation correlation spectrum can be obtained with a layer model. It is found that the measurement matches the theory very well as long as the particle concentration is low enough. However, as the particle concentration increases, the measured transmission fluctuation spectrum deviates gradually from the theory, which is a result of the high concentration effects. High concentration effects include particle overlapping and monolayer structure. In this work, theory and simulations on particle overlapping are studied. As a result, an empirical expression is found.