Title of article :
Chemical process opportunities for vibrated powders 3. Provisional design for an experimental sidewards flying bed
Author/Authors :
Squires، نويسنده , , A.M.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
Abstract :
At a scale suitable for laboratory experimentation, a provisional mechanical design illustrates a concept for a “sidewards flying bed” (SFB), a layer of particulate matter held upon the inner wall of a cylinder that rotates at varying speed. Acting upon the layer are centrifugal and tangential forces whose patterns of variation create time intervals during which the latter is the greater. During such intervals, the layer is postulated to respond by “flying sidewards.” In a laboratory SFB set-up, experiments can elucidate a new area of non-steady-state soil mechanics, with outcomes bearing upon a full-scale SFBʹs chemical processing potential. An important question is, what will be the delay in the SFB layerʹs taking flight after the moment tangential force just begins to exceed centrifugal? For the SFB design to be successful, this delay should be significantly shorter than a time interval during which the tangential force dominates.
eriments were to show this not to be so, a “what-then?” might be to install several stationary rakes near the cylinderʹs inner wall, parallel to its axis. Loosening the particulate layer as the cylinder turns, these should advance the timing of the layerʹs flight.
ing adequate flight in an experimental SFB could point to a design at a commercial scale capable of promoting rapid local mixing — more rapid than that afforded by conventional vibrated or fluid beds. Such should become a strong candidate for applications requiring rapid heating of hydrocarbonaceous matter followed by quick separation of vapor product and carbonaceous residue (e.g., flash pyrolysis of coal or oil-shale). The SFBʹs competencies should include ability to treat moieties of especially large size (e.g., for producing a smokeless solid fuel from coal, for heat-treating a metal part or a polymer, for flash-cooking foodstuffs without oil, for drying large particulates); ability to treat highly heterogeneous matter (e.g., for burning or gasifying comminuted biomass or solid wastes); and ability to promote excellent heat transfer between SFB and stationary surfaces embedded therein (e.g., in an air-cooled SFB steam-condenser).
Keywords :
Rotating vibrated bed , Flash shale oil distillation , Smokeless solid fuel , Flash coal pyrolysis , High-pressure flash hydrogenation of carbonaceous matter , Polymer curing , Steel heat treatment , Flash-cooking food , Air-cooled condenser , Biomass combustion , Refrigerated storage of unstable oils , Polymeric monomer recovery , Sidewards flying bed , Drying , Biomass gasification , Non-steady-state soil mechanics
Journal title :
Powder Technology
Journal title :
Powder Technology