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Showing result 1 - 5 of 39 swedish dissertations matching the above criteria.

  2. 1. Fluid Dynamics of the Bottom Bed of Circulating Fluidized Bed Boilers

    Author : Anders Svensson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluidized beds; circulating fluidized bed boilers; fluctuations; fluidization regimes; bottom bed; bed porosity; fluid dynamics; bubbling beds; circulating fluidized beds; non-slugging; bed expansion; particle concentration;

    Abstract : The fluid dynamic conditions in the furnace of a fluidized bed boiler influence the combustion and the production of harmful emissions. A substantial amount of the bed material in a circulating fluidized bed (CFB) boiler is present as a dense bubbling bottom bed. READ MORE

  4. 2. Disturbances in Fixed-Bed Combustion

    Author : Sven Hermansson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFD; modelling; packed bed; bed; combustion; channelling; grate furnace;

    Abstract : Conversion of solid fuels in fixed beds is a common method for heat and power production. A frequent fixed-bed technique in small to medium scale is combustion in grate furnaces. Grate furnaces are widely used in the industrial energy branch and appreciated for their stability and simplicity of control. READ MORE

  5. 3. Increased Productivity of Ferrous Alloys Produced by Powder Bed Fusion - Laser Beam

    Author : Rasmus Gunnerek; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; additive manufacturing; process optimization; build rate; build speed; powder bed fusion – laser beam; porosity; low alloy steel; 316L stainless steel; productivity in AM;

    Abstract : Low production speeds limit wider adoption of powder bed fusion – laser beam (PBF-LB) in cost sensitive industries as it correlates directly with high production costs. The main process parameters such as scan speed, hatch distance and layer thickness can be scaled up to increase build speed, but it often comes at a trade off in lower quality, i. READ MORE

  6. 4. Laser Based Powder Bed Fusion of Plain Carbon and Low-Alloy Steels: Microstructure and Processability

    Author : William Hearn; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low-Alloy Steel; Additive Manufacturing; Lack of Fusion Porosity; Laser Based Powder Bed Fusion; Plain Carbon Steel; Intrinsic Heat Treatment; Keyhole Porosity; Cold Cracking;

    Abstract : Despite the prominence of laser based powder bed fusion (LB-PBF) as an additive manufacturing technique, the number of alloys that have been approved for the process remains limited. In traditional manufacturing, ferrous alloys are the most common alloy group, consisting primarily of plain carbon and low-alloy steels. READ MORE

  7. 5. Powder degradation during powder bed fusion processing

    Author : Ahmad Raza; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser-based powder bed fusion; Alloy 718; Powder degradation; Oxidation; Electron beam powder bed fusion; Additive manufacturing; AlSi10Mg; Residual oxygen; Spatter particles; Sublimation.;

    Abstract : Powder bed fusion (PBF) techniques, including laser-based powder bed fusion (LB-PBF) and electron beam powder bed fusion (EB-PBF), are two rapidly growing additive manufacturing (AM) processes due to their ability to produce complex geometries in near-net shapes. To attain reproducibility and repeatability in PBF processes, a consistent set of powder properties is vital. READ MORE