Feasibility of utilizing a rotating fluidized bed for the removal of sulfur from hot gases. Progress report

The RFB provides an option for coal combustion systems by separating the desulfurization of hot combustion product gases from the combustion process itself. Fluid-bed combustors conventionally combine the two processes and, as a result, the rapid combustion process is carried out in equipment whose design is dominated by the requirements of the slower and temperature-specific desulfurization process. Neither process can be optimized and, in fact, the specifics of the combined reaction chemistry are unclear. Separation of the processes allows consideration of alternative combustors, sorbents, and sorption devices. The RFB desulfurizer has the potential to reduce equipment sizes through improvements in reaction rates and sorbent utilization. Additionally, separation of the combustion and sorption reactions leads to a relatively clean separation of ash and spent sorbent allowing for better waste utilization or disposal. Several process advantages are associated with the use of the rotating rather than the stationary fluidized bed for sulfur removal. These stem primarily from two characteristics inherent in the multi-g system. First, smaller particles can be retained in the fluidized bed, with the following three important advantages: (a) Smaller particles will contribute to higher sulfation rates because of increased surface area; the better rates will lead to a shorter gas residence time; (b) Greater sorbent utilization will occur. Sulfation causes the buildup of a product layer on the outside of the sorbent particles, which corresponds to a higher fraction of sorbent utilization in the case of a small particle than with a larger particle; (c) The low gas velocities possible in the fluidization of small particles will permit relatively long residence times

URANIUM-BISMUTH IN-PILE CORROSION TEST LOOP. RADIATION LOOP NO. 1

A loop was operated in the Brookhaven Graphite Research Reactor to determine the effect of in-pile irradiation on the corrosion of various materials by a U-- Bi solution. The loop wws fabricated of 21/4% chrome-1% Mo steel and contained, in the in-pile section, specimens of low-chrome steels, C steel, Mo, Be, Ta, and graphite. The U--Bi solution containing 869 ppm U/sup 235/ 98 ppm U/ sup 238/, 236 ppm Zr, and 346 ppm Mg was circulated at 51/4 gpm. A temperature difference of 75 deg C was maintained on the loop. The in-pile test section ran at 500 deg C and the finned cooler section at 425 deg C. The in-pile test section was exposed to a neutron flux of 4.4 x 10/sup 12/ neutrons/cm/sup 2/-sec which provided a fission density of 5.5 x 10/sup 10/ fissions/cm/sup 3/-sec. Metallographic examination indicated that the corrosion and/or erosion of the steel and graphite specimens was nil. Wetting of the specimens by the U-Bi solution was limited. Results indicate that in-pile and out-of-pile experimental results are similar and that fission fragment recoils did not contribute materially to either wetting or corrosion under the conditions imposed in this test. (auth