A novel approach to correlate heat transfer and pressure fluctuation in gas

Mollick, P. K., Goswami, P. S., Krishnan, M., Vijayan, P. K., & Pandit, A. B. (2019). A novel approach to correlate heat transfer and pressure fluctuation in gas–solid spouted bed. Particuology, 42, 26-34. https://doi.org/10.1016/j.partic.2018.05.006

A novel approach to correlate heat transfer and pressure fluctuation in gas–solid spouted bed

P.K. Mollick ^{a d *}, P.S. Goswami ^b, M. Krishnan^a, P.K. Vijayan ^c, A.B. Pandit ^d

a Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085, India
b Department of Chemical Engineering, Indian Institute of Technology-Bombay, Mumbai 400076, India
c Reactor Engineering Division, Bhabha Atomic Research Centre, Mumbai 400085, India
d Department of Chemical Engineering, Institute of Chemical Technology, Mumbai 400019, India

10.1016/j.partic.2018.05.006

Volume 42, February 2019, Pages 26-34

Received 31 October 2017, Revised 20 March 2018, Accepted 21 May 2018, Available online 22 November 2018, Version of Record 21 January 2019.

E-mail: pkmollick@gmail.com; pmollick@barc.gov.in

Highlights

• Heat transfer at high temperature was studied in a conical spouted bed for various heating rates.

• Heat transfer rate was well correlated with pressure fluctuation.

• Intensity of PSD peak was dependent on thermal properties of bed and gas.

Abstract

Statistical analysis of pressure fluctuations in spouted beds has been used as a well-established diagnostic tool to determine bed and flow characteristics because of its smooth operation. However, in many recent and conventional applications of spouted beds such as drying, coal gasification, catalytic conversion, biomass treatment, and chemical vapor deposition, direct estimation of the heat transfer rate from the solid bed to the gas or vice versa has proven to be difficult. A variance and spectral analysis of pressure fluctuation is extended here to characterize the heat transfer phenomena in a spouted bed. In the present study, zirconia and alumina were used as the bed materials, and argon and nitrogen were used as the spouting gases. Experiments were conducted at various heating rates for different superficial gas velocities for a range of temperatures up to 300 °C. Significant changes in the gas density and viscosity with different extents of heat transfer were observed to affect the momentum diffusivity and gas–particle interaction, which in turn led to local pressure fluctuations, causing the bed to behave differently. In the present work, a novel approach is proposed to establish a link between local pressure fluctuation and the extent of heat transfer in the bed. This method shows potential for correlation of the statistics of pressure fluctuation with the thermal properties of individual solids and gases. Thus, the technique can be extended to many industrial applications for the indirect estimation of the extent of heat transfer and prediction of unknown thermal properties of products in solids or gases.

Graphical abstract

Keywords

CVD; Chemical vapor deposition; PSD; Power spectral density

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