Air Products and Chemicals, Inc.

Pierre L Brian

Michael S Chen

Sheldon W Dean, Jr

William Joseph Mazzafro

Suresh M Vora

A process for enhancing heat transfer between combustion products formed in a fluidized bed combustion (FBC) reactor and the water-containing tubes surrounding the reactor wherein particles of an inert material, e.g., mineral calcium sulfate (gypsum), having a spheroidal shape ranging in size from about 50 to 1000 .mu.m and having a Moh's hardness of between 2.0 and 4.0 are introduced into the reactor in the presence of a solid fuel and an oxygen-containing gas. Introduction of such particles into the FBC reactor increases the particle density within the reactor thereby increasing radiant and convective heat transfer between the circulating bed and the surrounding water cooled walls. The improved process allows more precise control of the operating temperature regime. Erosion of the reactor walls is also substantially reduced.

Fluidized bed combustion heat transfer enhancement

This invention relates to an improved process for reducing solute in a vapor stream and, particularly, to the adaption of this process in concentrating solutions in an evaporator wherein the solution is heated to volatilize solvent. The improvement for reducing solute in the vapor stream resides in (a) the utilization of a wire mesh mist eliminator pad having a wire diameter of from 0.001-0.05 inches, an interfacial area from 50-200 ft.sup.2 /ft.sup.3, a void space of about 90-99 percent and a packing thickness of 4-16 inches and (b) spraying a liquid through the mist eliminator pad, the liquid being sprayed uniformly over the surface of the mist eliminator pad at a rate of 0.6-2.5 pounds liquid per pound of vapor to provide a wetting rate of 0.1-0.25 gallons per minute per square foot of mist eliminator surface area. The process has been particularly advantageous in the multistage concentration of corrosive products particularly in the concentration of a 60-70% sulfuric acid solution to about 93 percent.

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Allentown, PA, United States of America

Pierre L Brian