Electrified calcination in a fluidized bed calciner – Experiments with Scaled Binary particles
Master thesis
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https://hdl.handle.net/11250/3076852Utgivelsesdato
2023Metadata
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Sammendrag
Fluidized bed calcination is a process that is used in various industries to heat a bed of particles to high temperatures for chemical reactions and calcination. However, traditional methods can be energy intensive and result in uneven heating. Electrified calcination is a promising alternative to improve efficiency and performance, especially in the cement industry, which is a significant emitter of CO2. The ELSE project explores the feasibility of electrified calcination using a Bubbling Fluidized Bed Reactor with immersed heating elements. Studies have shown that a binary mixture of smaller raw meal particles and coarser particles can enhance fluidization properties. The work aims to investigate the behaviour of particles in a fluidized bed reactor under cold-flow conditions that simulate hot-flow conditions. Binary particles study the dynamics and feasibility of fluidizing raw meal with coarser particles while separating them from the system. Tests in cold-bed reactors will be conducted to understand the effects of particle characteristics on fluidization processes and optimize industrial processes. Experiments were conducted on fluidized bed particles in a narrow rectangular column under scaled cold-flow conditions. The study found that pure coarse particles have good fluidization behaviour, while pure fine particles have poor fluidization behaviour. Mixing fine particles with coarse particles is feasible, but may result in entrapment, poor mixing, and reduced fluidization performance. Segregation can occur due to differences in particle size or density, and increasing the particle size difference increases the possibility of segregation. Understanding particle characteristics is crucial for optimizing reactor performance. There may be a slight change in the chemical composition of segregated particles due to erosion or breakdown during fluidization, but the segregation process used in the experiment is effective.