The objective of this study was to relate experimental pressure fluctuation behavior to the transition in mode of flow observed in fluidized dense phase pneumatic conveying of fly ash. Shannon entropy and wavelet analysis were utilized to extract features of the flow regimes. Daubechies db4 wavelet analysis of pulsating air pressure revealed that the flow mechanism of fly ash in a fluidized dense phase possessed non-steady characteristics associated with gradual aeration of dunes along the direction of flow. Variations of Shannon entropy values along the length of the pipeline were assessed to determine the location at which the flow converted from dense to dilute phase mode. The effects of conveying parameters and specific power consumption on Shannon entropy and variations of the local power consumption coefficient are discussed. © 2019 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences

Niranjana Behera

Department of Design and Automation

School of Mechanical Engineering

Vellore Campus

Alkassar Y

Agarwal V.K

Pandey R.K

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

Particuology

Experimental study and Shannon entropy analysis of pressure fluctuations and flow mode transition in fluidized dense phase pneumatic conveying of fly ash

The objective of this paper is to report the experimental findings related to the pressure fluctuations in the fluidized dense phase pneumatic conveying of fine powders in the pipeline. Investigation has also been carried out to understand the relation between pressure pulse characteristics and specific power consumption and pneumatic conveying parameters. In addition, the transition in mode of flow along the downstream of flow of fine powders has been assessed and discussed. The wavelet analysis (Daubechies db4 wavelet) of signals of air pulses revealed that the moving bed flow possesses the transient feature and pulsatile phenomenon characterized by multiple amplitudes and random frequencies. Variations of pulse structures along the length of pipeline have been observed due to occurring of frequent aeration and de-aeration of dunes during the conveying. Substantial variations in pulse structures have also been found with different types of bulk materials. Pulse velocities of air between two data points are found higher at high solid loading ratios leading to low voidage in case of dense phase flow. © 2018 Elsevier B.V.

Powder Technology

Transient characteristics of fine powder flows within fluidized dense phase pneumatic conveying systems

During the process of pneumatic conveying of fine particles, the flow mode may change from dense to dilute. In studying this mode change, we evaluate three parameters (Hurst exponent, Shannon entropy, and phase-space attractor size) used in signal analysis. Experimental data of pneumatic conveying of fly ash at three locations along a 173-m-long pipeline were used for this analysis. Variations in magnitude of the Hurst exponent, Shannon entropy, and size of the phase space attractor exhibit different trends in their variations for dense and dilute mode of flow. From these trends it is possible to predict the change from dense to dilute mode and the location along the length of the pipeline of this change in mode of flow. © 2016 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences

Transient parameter analysis of pneumatic conveying of fine particles for predicting the change of mode of flow

Solids friction factor is a parameter required for predicting the pressure drop in a process of pneumatic conveying. It depends upon a number of non-dimensional parameters. In this paper, experimental data for a 2. m long section of a 173. m long pipeline has been used to develop a mathematical model for solids friction factor. The model predicts the pressure drop with a low error margin for the 2. m long pipeline. Although the model has been developed for a 2. m long straight pipeline with fly ash as the conveying material, it has also been scaled-up for a 173. m long straight pipeline. By scaling-up, the predicted pressure drop lies within an acceptable error margin. Since the model seems to be having less dependence upon the parameter of particle density, it predicts the pressure drop with less error margin for the experimental data of other conveying materials such as alumina and cement. The model shows high error in predicting pressure drop for the experimental data for a different pipeline configuration. © 2015 Elsevier B.V.

Journal	Data powered by TypesetParticuology
Publisher	Data powered by TypesetElsevier BV
ISSN	1674-2001
Open Access	0