Tracing the motion of a large object in a fluidized bed using electrical capacitance tomography

Abstract An innovative method using electrical capacitance tomography (ECT) to trace a large object's motion on an air distributor in a fluidized bed is described here. The method fills the large object to be traced with a high permittivity material, and then a recalibration process is applied to reduce the nonlinearity caused by the large permittivity difference between the tracer particle and other fine particles in the measurement zone. The local dynamic threshold selection method is performed on the reconstructed image to locate the tracer particle's position. Static simulations and dynamic experiments testify that tracer particles with a diameter of one ninth of the measured cross-section and a fluidization velocity v / v cr ≤4.2 can be accurately located and traced. Employing this method to trace the motion of a spherical object in a bed shows that the fluidization velocity significantly influences the directional motion of a large, heavy object on an inclined air distributor.

[1]  Kim Dam-Johansen,et al.  Single-particle behaviour in circulating fluidized beds , 1997 .

[2]  Tong Zhao,et al.  Sensor design and image accuracy for application of capacitance CT to the petroleum refinery process , 2007 .

[3]  Jpk Seville,et al.  Solids motion in bubbling gas fluidised beds , 2000 .

[4]  Tomasz Dyakowski,et al.  Estimation of particulate velocity components in pneumatic transport using pixel based correlation with dual plane ECT , 2007 .

[5]  Tomasz Dyakowski,et al.  On-line monitoring of dense phase flow using real time dielectric imaging 1 The authors are members , 1999 .

[6]  J. Halow,et al.  Innovative Method Using Magnetic Particle Tracking to Measure Solids Circulation in a Spouted Fluidized Bed , 2010 .

[7]  B Formisani,et al.  A fundamental approach to the phenomenology of fluidization of size segregating binary mixtures of solids , 2001 .

[8]  Pradeep K. Agarwal,et al.  Circulatory motion of a large and lighter sphere in a bubbling fluidized bed of smaller and heavier particles , 1994 .

[9]  J. S. Dennis,et al.  The rise of a buoyant sphere in a gas-fluidized bed , 2005 .

[10]  Alex C. Hoffmann,et al.  PARTICLE SEGREGATION IN FLUIDISED BINARY MIXTURES , 1993 .

[11]  Martin Rhodes,et al.  Hydrodynamic similarity of solids motion and mixing in bubbling fluidized beds , 2003 .

[12]  T. Longo,et al.  The fluidization process of binary mixtures of solids: Development of the approach based on the fluidization velocity interval , 2008 .

[13]  Liang-Shih Fan,et al.  Dynamics of spiral bubble plume motion in the entrance region of bubble columns and three-phase fluidized beds using 3D ECT , 2005 .

[14]  Krzysztof Grudzień,et al.  Application of ECT to solid concentration measurements during granular flow in a rectangular model silo , 2010 .

[15]  L. Landweber.  An iteration formula for Fredholm integral equations of the first kind , 1951 .

[16]  Baosheng Jin,et al.  Experimental investigation on mixing and segregation behavior of biomass particle in fluidized bed , 2009 .

[17]  Wuqiang Yang,et al.  Electrical capacitance tomography for gas–solids flow measurement for circulating fluidized beds , 2005 .

[18]  Antonio Soria-Verdugo,et al.  Motion of a large object in a bubbling fluidized bed with a rotating distributor , 2011 .

[19]  Robert F. Mudde,et al.  Analysis of chaos in fluidization using electrical capacitance tomography , 1996 .

[20]  C. Dechsiri,et al.  PET investigation of a fluidized particle: spatial and temporal resolution and short term motion , 2005 .

[21]  David Parker,et al.  Positron emission particle trackingApplication and labelling techniques , 2008 .

[22]  Qiang Zhang,et al.  Particle Measurement Sensor for in situ determination of phase structure of fluidized bed , 2009 .