Fluidized bed reactor

#1. Field of the Invention

#The present invention relates to fluidized bed reactors wherein solids are contacted with gases promoting chemical and physical reactions to the solids, and involving heat, mass and momentum transfer, and transport phenomena.

#2. History of the Invention

#FIG. 1, is a cross sectional side elevation view of a schematic fluidized bed reactor of the present invention showing the reactor interior, a fluidized bed therein, a plenum volume filled with unfluidized solids with constriction plate segments shown connected to a gas manifold between the fluidized bed and the plenum volume;

#FIG. 2(a), a sectional view taken along the line 2(a)--2(a) in FIG. 1, showing the tops of the constriction plate sections with tuyeres and plenum pipes extending therefrom;

#FIG. 2(b), a sectional view taken along the line 2(b)--2(b) in FIG. 1, showing a section through windboxes of the constriction plate sections showing the plenum pipes as extending therethrough;

#Referring now to the drawings:

#FIG. 1 shows schematically a sectional side elevation of a fluidized bed reactor 10, hereinafter referred to as reactor. The reactor 10 is contained within a cylindrical housing 11 that includes an outer shell 11a preferably fabricated from steel and an inner refractory lining 11b and contains a constriction plate 12 arranged thereacross and supporting a bed 13 of fluidized solids. A single fluidizing gas inlet 14 is provided that connects to a manifold 15 within the cylindrical housing 11. Fluidizing gas is passed from the manifold 15 through distributor pipes 16 and the interior, hereinafter referred to as windbox, of constriction plate segments 17, hereinafter referred to as segments, the upper surfaces of segments 17 constitute the constriction plate 12 that supports the bed 13. It should be understood that reactor 10 would be constructed, as are most fluidized bed reactors, to include internal high-temperature refractory and abrasion resistant linings illustrated as refractory lining 11b, and external insulation for the reactor and inlet and exit gas lines, fluidizing blowers or compressors, fluidizing gas preheaters, thermocouple and pressure tap wells, dust collectors, instrumentation, and the like, and could be constructed in stages. Therefore, the representation of FIG. 1 should be taken as a schematic only, and it should be understood that reactor 10 would also include such components.

#The fluidized bed 13 of reactor 10 is fed with solids entering through line 18, with product solids withdrawn through line 19 to maintain a bed level 20. As stated above, fluidizing gas enters through line 14, passes into manifold 15 that is located in plenum volume 21, hereinafter referred to as plenum, surrounded, as will be explained hereinbelow, with plenum solids 22. The fluidizing gas from manifold 15 travels through distributor pipes 16 and into the segments 17 wherefrom it is distributed through open tuyeres 23, hereinafter referred to as sifting tuyeres, into fluidized bed 13. The fluidizing gas is either heated prior to passage through inlet pipe 14 as for drying the fluidized bed 13, can be for burning in that bed, or in rare circumstances, could be burned in the segments 17 and then passed into the fluidized bed 13. The segments 17 are preferably constructed by welding of appropriate grades, preferably austenitic types and heavy gauge thicknesses of stainless steel. The choice of stainless or alloy steel depends upon the design temperature within the windbox and gaseous atmosphere (oxidizing or reducing) therein. Thus, fluidizing gas enters through distributor pipes 16 and exits through sifting tuyeres 23 into fluidized bed 13. Gases from bed 13 then pass through a freeboard 20a within the reactor housing 11 where solids are disengaged, falling back to the fluidized bed 13, the off gas passing out through line 25. Segments 17 are supported during assembly by metallic members or beams 26, such as I-beams, or the like, with, when the reactor 10 is in operation, the constriction plate segments 17 and fluidized bed thereabove will be otherwise supported by plenum solids 22.