Bubble size control in a two-dimensional fluidized bed using a moving double plate distributor

Date

1998-03-01

Author

Koksal, M
Vural, H

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

110
views

0
downloads

Pulsating the flow in a fluidized bed by using a moving double plate distributor (MDPD) lo control the bubble size and enhance the fluidization characteristics is a new approach. In this novel design, a second plate Is placed under the existing distributor such that it can make a reciprocating motion generating pulses to the flow field. The frequency and amplitude of the pulsation can be adjusted to break up the large bubbles in the bed. The aim of this study is to investigate the effect of pulsation on the bubble size, bubble speed, bubble fraction and bed expansion in a fluidized bed. For this purpose, the bubbles were followed two-dimensional fluidized bed with turnip seed and sand as the bed material for different pulsation frequencies and operating velocities. Bubble size, speed and bed expansion were measured for pulsed flow and compared with those of continuous flow. Image processing techniques were utilized to measure the bubble fraction. Interesting bubble flow patterns were observed and a significant decrease in bubble size was achieved for the pulsed flow. (C) 1998 Elsevier Science S.A.

Subject Keywords

Bubbles, Fluidized beds, Distributors, Pulsed flow, Image processing

URI

https://hdl.handle.net/11511/66022

Journal

POWDER TECHNOLOGY

DOI

https://doi.org/10.1016/s0032-5910(97)03337-8

Collections

Department of Mechanical Engineering, Article

Suggestions

OpenMETU
Core

Flow correction control with electromagnetically induced preform resting process Poorzeinolabedin, Mohsen; Parnas, Kemal Levend (Springer Science and Business Media LLC, 2019-06-01) Resin flow correction control with electromagnetic field source, a new variation of the vacuum-assisted resin transfer molding (VARTM) process called electromagnetically induced preform resting (EIPR) for dynamical resin flow controlling is introduced to manipulate the flow front and local permeability to prevent the formation of dry spots. This paper proposes an active and real-time flow control approach that is implemented during the composite laminate infusion. The EIPR process applies an electromagnetic...
Flow behavior and regime transition in a high-density circulating fluidized bed riser Kim, SW; Külah, Görkem; Bi, H; Lim, CJ; Grace, JR (2004-09-01) Flow behavior and flow regime transitions were determined in a circulating fluidized bed riser (0.203 m i.d. x 5.9 m high) of FCC particles (d(p) = 70 pm, rho(p) = 1700 kg/m(3)). A momentum probe was used to measure radial profiles of solids momentum flux at several heights and to distinguish between local net upward and downward flow. In the experimental range covered (U-g = 5-8 m/s; G(s) = 22-345 kg/m(2) s), the fast fluidization flow regime was observed to coexist with dense suspension upflow (DSU). At a...
A Novel System for Measuring Solids Dispersion In Circulating Fluidized Beds Külah, Görkem; Bi, H T; Lim, C J; Grace, J R (null; 2008-05-08) A novel, simple and accurate experimental measurement system with fast response was developed to measure transient local solid tracer concentration distributions to obtain information on solids mixing and dispersion in risers of circulating fluidized beds operating at a wide range of operating conditions. Phosphorescent-coated FCC particles, used as the tracer, were activated by high intensity UV light and injected at the return leg of high-density circulating fluidized bed (HDCFB) unit. The tracer concentr...
Coupling of spectral thermal radiation model with a comprehensive system model for co-combustion of biomass in bubbling fluidized bed Yaşar, Mehmet Soner; Selçuk, Nevin; Külah, Görkem (2023-02-01) A previously developed 1-D comprehensive model for a bubbling fluidized bed combustor (BFBC) co-firing lignite with cotton residue and limestone is coupled with a 3-D spectral and gray radiation models utilizing method of lines (MOL) solution of discrete ordinates method (DOM). The performance of the coupled models is assessed by comparing their predictions of temperature profiles and gaseous emissions (i) with those of original FBC model without coupling and (ii) with the in-situ measurements from Middle E...
High Speed Couette—Poiseuille Flow Stability in Reverse Flow Conditions Ebrinç, Ali Aslan; Özgen, Serkan; Dursunkaya, Zafer (2006-08-21) The linear stability of reverse high speed-viscous plane Couette – Poiseuille flow is investigated numerically. The conservation equations along with Sutherland’s viscosity law are studied using a second order finite difference scheme. Basic velocity and temperature distributions are perturbed by a small amplitude normal-mode disturbance. Small amplitude disturbance equations are solved numerically using a global method to find all the eigenvalues at finite Reynolds numbers. The results indicate that instab...

Citation Formats

M. Koksal and H. Vural, “Bubble size control in a two-dimensional fluidized bed using a moving double plate distributor,” POWDER TECHNOLOGY, pp. 205–213, 1998, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/66022.