Case studies for selective agglomeration detection in fluidized beds: Application of a new screening methodology

Development of a non-invasive optical technique to study liquid evaporation in gas–solid fluidized beds

“…Features Temperature probes [1,9,12,22] • Fast and robust • Invasive • Sticking, difficult interpretation [9] and [12] • Mostly employed for time averages Suction probes [9,14] • Mainly for time averaged gas composition profiles • Invasive • Potential for bias by sticking liquid Pressure probes [2,21,20,36] • Common indicator of change of fluidization regime [2,21,20] • Other techniques required to confirm interpretation [20,36] Tribo-electric probes [3,6,26] • Invasive • Sensitive to local hydrodynamics the infrared, and presents a method to detect the dense emulsion phase using the camera detecting visual light, to ensure proper application of the calibration. Therefore, this method, unlike that by [25], also works for wide temperature distributions in the solid phase.…”

Early detection of agglomeration in a polyethylene fluidized bed at high temperature and pressure by vibration signature analysis

“…Several intrusive and non-intrusive measurement techniques have been utilized for monitoring the hydrodynamics of fluidized beds. Measurement of pressure fluctuation have been used by many researchers for determining changes in the particle size (Davies and Fenton, 1997;Weinstein et al, 2000), predicting the onset of defluidization (Mettanant et al, 2009), detecting hydrodynamic changes (Ibrehem, 2009;Bartels et al, 2010;Mansourpour et al, 2014) and early detection of agglomeration (Schouten and van den Bleek 1998;van Ommen et al, 2000;Nijenhuis et al, 2007;Gheorghiu et al, 2004). Acoustic emissions have been applied in various fluidized beds to characterize the fluidization state or regime changes (Zukowski 1999;Tsujimoto et al, 2000;Salehi-Nik et al, 2009).…”

“…As can be seen in Fig. 7, each curve demonstrates a sharp decrease which occurs at the same temperature that the standard deviation exhibits a maximum in Fig 3. According to Bartels et al (2010), a strong decrease in the power density takes place during the agglomeration. Therefore, the sharp decrease in Fig.…”

Measurement, monitoring and control of fluidized bed combustion and gasification

“…Bartels et al (2009) proposed a new methodology to asses many different signal analysis methods in combination with pre-treatment (filtering methods). They demonstrated this approach for pressure fluctuation signals (Bartels et al, 2010b), but it can be used to study the characteristics of other signals as well. This approach yields a matrix that indicates for every combination of pre-treatment and analysis methods the selectivity for agglomeration compared with other changes in, e.g., gas velocity or bed mass.…”