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Fluidized bed reactors are utilized in a variety of applications from hydrocarbon cracking to drying of mineral ore to coating of pharmaceutical pills. A proper understanding of bed hydrodynamics is essential to properly design, operate and control the process. Intrusive and non-intrusive measurement techniques have been utilized to study various aspects of fluidized bed behaviour. Electrical Capacitance Tomography (ECT) has been utilized to determine the distribution of gas-solid mixture in the bed. The Digital Image Analysis Technique (DIAT) is used to determine the bubble behavior in two-dimensional beds. The bubble behavior has not been studied by ECT. The premise of this research is to test a new technique by combining ECT solid fraction maps with image processing techniques to determine the bubble characteristics in the bed. Electrical Capacitance Tomography (ECT) was used to map the relative fractions of sand-air mixture in a 14 cm ID acrylic vessel at two different static bed heights. The voids were defined as the areas of gas-solid mixture with value of less than 0.25. Afterwards simple image analysis techniques were applied to isolate bubbles from the rest of the bed. The resulting data were converted into binary images to extract hydrodynamic information. The two main parameters of interest were the bubble diameter and its rise velocity. The experimental average velocities and average diameters matched the results obtained from respective correlations in the literature. However, large spreads existed for both these parameters due to the simultaneous presence of bubbles and slugs. The experimental fluidized bed did not transition fully into the turbulent regime but has the character of a hybrid bubbling-slugging regime. This is illustrated by experimental diameters which indicate presence of bubbles and slugs simultaneously. The same information was illustrated by experimental velocity-diameter envelopes (minimum and maximum values) which overlapped for higher flow conditions. The radial solid fraction distribution illustrated the same point with an inverted “M” profile which has been associated previously with regime transition. The path of bubble rise was identified, mainly rising through the midway point between the bed’s center and its inner edge. Five different types of bubbles were identified using the two dimensional binary images of voids. However, this technique can only be used for regimes where voids/bubbles are the main source of gas transfer to the surface of the bed.

Palaeoecological data can provide key information on depositional environments. This may be critical to the interpretation of marine sedimentary cycles and the recognition of ancient cycles and sequences. Although many recent studies have attempted to combine palaeoecology and sequence stratigraphy, the sequence stratigraphic model is commonly used to provide a temporally constrained framework for the evaluation of ecological and evolutionary events. This study shows how palaeoecology can be used as a powerful tool in the development of sequence stratigraphic models. A palaeoecological study of three Lower Cretaceous successions (at Ericeira, Cascais, Cabo Espichel) from the southern part of the Lusitanian Basin, Portugal, provides a basis for this study. This palaeoecological analysis allowed the construction of a detailed picture of the effects of relative sea-level, and other environmental factors, on sedimentary succession evolution. The results of this palaeoecological analysis have been represented on a series of depositional facies trend diagrams. The depositional facies diagrams have then been used to develop the sequence stratigraphy of the southern part of the Lusitanian Basin. The study successions record the temporal changes, and along-strike variation, in the evolution of three mixed carbonate-siliciclastic systems. The base of all the successions represents the development of narrow shelf with minor wave reworking. Siliciclastics were introduced by sand and gravel-load river dominated deltas with little reworking of the sediment at the channel mouths. This was characterised by the development of a clastic beach-barrier at Ericeira and a 'cool-water' carbonate ramp at Cascais. At Cabo Espichel a coral biostrome developed where coral ecology was controlled by terrigenous sedimentation and turbidity. The upper part of the successions represent a change in the morphology of the basin. A broad, shallow, low energy carbonate shelf developed that dissipated wave energy. In the nearshore environment siliciclastics were prevalent. The shelf carbonates are characteristic of the 'cool-water' type carbonates of the Cretaceous Tethyan realm. The more proximal Ericeira and Cabo Espichel successions record the alternation between marginal marine siliciclastic and shallow-water marine carbonate environments. The Cascais succession is characterised by carbonate platforms with abundant coral and rudist bivalve faunas. Palaeoecological analysis and development of the depositional facies trend diagrams have allowed the identification of one mega-sequence (2nd order), six sequences (3rd order) and higher resolution sequences and parasequences (4th order). 2nd and 3rd order sequences are correlatable across the southern part of the Lusitanian Basin. They also correlate with previously published sequence chronostratigraphy for the Tethyan realm. The palaeoecological analysis indicates that 2nd and 3rd order sequences are controlled by allocyclic processes and that 4th order cycles (sequences and parasequences) were dominated by autocyclic processes. As a result 4th order cycles cannot be correlated across the basin. This study has shown that detailed palaeoecological analysis can reveal a detailed, and more accurate, picture of the controls on the development of a basin fill than sedimentology alone. Along with the depositional trend diagrams, these data can provide a powerful method for the development of a sequence stratigraphic model and aid to interpretation of a basin fill.

Diss. (sammanfattning) Stockholm : Univ., 2001. / Härtill 5 uppsatser.

Thesis (Ph. D.)--University of Adelaide, Dept. of Chemical Engineering, 1993? / Includes bibliographical references (leaves 290-303).

Thesis (Ph. D.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xi, 120 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 103-108).

Thesis (Ph. D.)--University of California, Santa Cruz, 1976. / Includes bibliographical references (leaves 165-173).

Thesis (Ph. D.)--Oregon State University, 1986. / Includes bibliographical references (leaves 125-135).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 185-187).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 44-47).