Pressure fluctuations as a diagnostic tool for fluidized beds. Technical progress report, July 1, 1996--September 30, 1996

PDF Version Also Available for Download.

Description

By studying pressure fluctuations using a system identification approach, it is hypothesized that circulating fluidized bed (CFB) pressure fluctuations are indicative of CFB hydrodynamics in two ways. First, the frequency phenomenon that is observed in the lower regions of the CFB under conditions of high solids loading is the result of lower dense bed voidage oscillations. Our results suggest that a surface wave phenomena inversely proportional to the square root of the bed diameter is also be observed in CFB pressure fluctuations under most conditions. By matching revised similitude parameters between two CFBs a number of conclusions can be drawn. ... continued below

Physical Description

28 p.

Creation Information

Brown, R.C. & Brue, E. October 10, 1996.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

By studying pressure fluctuations using a system identification approach, it is hypothesized that circulating fluidized bed (CFB) pressure fluctuations are indicative of CFB hydrodynamics in two ways. First, the frequency phenomenon that is observed in the lower regions of the CFB under conditions of high solids loading is the result of lower dense bed voidage oscillations. Our results suggest that a surface wave phenomena inversely proportional to the square root of the bed diameter is also be observed in CFB pressure fluctuations under most conditions. By matching revised similitude parameters between two CFBs a number of conclusions can be drawn. First, spectral analysis of pressure fluctuations, if properly applied, can be used to verify that similitude has been achieved. To do this, not only must the Bode plot characteristics important for hydrodynamics be identified, but the pressure fluctuation structure at all elevations of the CFB must be similar. The set of similitude parameters defined by Glicksman is not sufficient to establish hydrodynamic similitude. The solids flux as typically measured in the downcomer does not contain information on the solids hold-up in the riser, or the amount of solids that progress downwards in the annulus rather than exit the riser. It is better to use the total mass contained in the riser as the important ``solids`` parameter for the establishment of similitude, rather than the solids flux. This measurement can be made more accurately, monitored continuously, and is a much simpler measurement to perform in most CFB systems. Even with this new set of dimensionless parameters, the differences in the coefficient of restitution of particle/bed collisions may make a significant difference in the CFB hydrodynamics. The effects of particle collisions with the riser top-plate must be considered in similitude studies.

Physical Description

28 p.

Notes

OSTI as DE97050774

Source

  • Other Information: PBD: 10 Oct 1996

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Other: DE97050774
  • Report No.: DOE/PC/94210--T6
  • Grant Number: FG22-94PC94210
  • DOI: 10.2172/418270 | External Link
  • Office of Scientific & Technical Information Report Number: 418270
  • Archival Resource Key: ark:/67531/metadc679228

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • October 10, 1996

Added to The UNT Digital Library

  • July 25, 2015, 2:20 a.m.

Description Last Updated

  • Nov. 11, 2015, 1:12 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 3

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Brown, R.C. & Brue, E. Pressure fluctuations as a diagnostic tool for fluidized beds. Technical progress report, July 1, 1996--September 30, 1996, report, October 10, 1996; United States. (digital.library.unt.edu/ark:/67531/metadc679228/: accessed October 23, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.