Improved gas distributor for coating HTGR fuel particles

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:7209984

Lackey, W J; Stinton, D P; Sease, J D

The important criteria to be considered in design of the gas distributor are: (1) The distributor should ideally spread or disperse the gas over the full area of the coating chamber to maximize the particle gas contact area and thereby increase both particle circulation and the percentage of the input gas that ends up as coating. (2) The gas should not heat up during its passage through the distributor. Otherwise the gas would partially decompose prematurely, causing excessive coating deposition within or on the distributor. (3) The distributor should be designed to minimize accidental drainage of particles from the furnace and blowover of particles into the effluent system. (4) The distributor should be capable of depositing both carbon and SiC coatings of high quality as regards to density, preferred orientation, permeability, defective fraction, and other product attributes. (5) The distributor should be amenable to use with large particle charges and short turnaround times and be simple, inexpensive, and reliable. We have devised a simple distributor that incorporates the five criteria listed above. The new design is termed a blind-hole frit. All the gas passes through the thinned blind-hole regions, and thus the gas velocity is considerably higher than for a flat frit of uniform thickness. Because of its high velocity, the gas does not have time to reach a high enough temperature to cause deposition within the frit. Also most of the resistance to gas flow is provided by the porous distributor and not by the particle bed; therefore, localized variations of the quantity of particles above any particular gas inlet do not significantly alter the flow rate through that inlet.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 7209984
• Report Number(s): CONF-770611-2
• Country of Publication: United States
• Language: English

Related Subjects

050700* -- Nuclear Fuels-- Fuels Production & Properties
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360601 -- Other Materials-- Preparation & Manufacture
CARBIDES
CARBON
CARBON COMPOUNDS
COATED FUEL PARTICLES
DEPOSITION
ELEMENTS
FLUIDIZED BED
FUEL PARTICLES
FURNACES
NONMETALS
PRODUCTION
PYROLYTIC CARBON
SILICON CARBIDES
SILICON COMPOUNDS
SURFACE COATING