Abstract: Apparatus to reduce or eliminate fluid bed erosion in fluidized bed combustion boilers by increasing the fire-side tube temperature by adding appropriately dimensioned longitudinal or circumferential fins to the inbed heat exchange tubes in the reactor.

Abstract: A method and apparatus for determining the zeta potential of particles in a suspension comprising: a cell containing at least a portion of the suspension of particles; a first electrode and a second electrode disposed in a cell; means for producing an electric field between the first and second electrodes, the electric field causing the particles to accelerate; means for converting a force, the force being generated by the acceleration of the particles, into electrical energy; and means for measuring the electrical energy.

Abstract: A method for treating the fine-grained spend absorbent (primarily calcium sulfite and calcium sulfate) from a dry flue gas desulfurization process. The absorbent, having a small amount of binder therein, is oxidized in a fluidized bed reactor at a temperature in the range from about 700.degree. C. to about 1000.degree. C. to produce a dry essentially fully oxidized pelletized calcium sulfate product.Calcium sulfate pellets having an average diameter of from about 0.5 mm to 5 mm and containing from about 1% to about 3%, by weight, of binder constituents, are composed of agglomerated calcium sulfate particles having an average diameter of from about 50.mu. to about 100.mu. bound to each other by the binder constituents.