Modifying geld art classification for various cohesion forces

Tal Yehuda, Haim Kalman

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Fluidized beds (FB) have significant applications in various industries. Classical Geldart classification is used for a long time to classify materials to four groups, each behave differently in a fluidized bed. Geldart's classification is based on the relationship between the particle and fluid density difference and the particle diameter. The four groups show behavior related to the cohesion forces. Group C has very high cohesion forces to create channels or rising plugs. Group A has countable cohesion forces while particles behave as individuals to present a bed volume increase at fluidization. Groups B and D are big enough to have negligible cohesion forces show none of the above-fluidization starts as bubbling and slugging. However the classical Geldart classification is based on dry materials in which the major cohesion force is related to Van der Waals force. In this research the effect of other cohesion forces on the classification is examined. A number of materials were tested at various moisture contents to present cohesion forces by liquid bridges. By these tests materials originally classified in groups B or D behaved like groups C or A at various moisture contents. Further, experiments with liquid fluidization were conducted. In this case there are no liquid bridge forces and also the Van der Waals forces are negligible. Indeed, even materials originally classified to groups C or A are expected to behave like groups B or D. In this way, Geldart's classification can be modified to consider various cohesion forces.

Original languageEnglish
Title of host publication18th International Conferences on Transport and Sedimentation of Solid Particles, T and S 2017
EditorsVaclav Matousek, Jerzy Sobota, Pavel Vlasak
PublisherWydawnictwo Uniwersytetu Przyrodniczego we Wroclawiu
Pages401-408
Number of pages8
ISBN (Electronic)9788377172698
StatePublished - 1 Jan 2017
Event18th International Conferences on Transport and Sedimentation of Solid Particles, T and S 2017 - Prague, Czech Republic
Duration: 11 Sep 201715 Sep 2017

Publication series

NameInternational Conferences on Transport and Sedimentation of Solid Particles
ISSN (Print)1232-3071

Conference

Conference18th International Conferences on Transport and Sedimentation of Solid Particles, T and S 2017
Country/TerritoryCzech Republic
CityPrague
Period11/09/1715/09/17

Keywords

  • Fluidized bed
  • Geldart's classification
  • Interparticle forces

Fingerprint

Dive into the research topics of 'Modifying geld art classification for various cohesion forces'. Together they form a unique fingerprint.

Cite this