| 摘要 |
Tubular or rod-shaped pieces of a metal having a holding-back capability, with respect to the principal atomic or molecular contaminant in a gas, are arranged in the interior of a containing cylinder through which the gas flows, so as to provide passages for gas flow along the surface of the filter material pieces, the latter being typically disposed with their long dimension parallel to the direction of gas flow. The particles first stick on the surface, then diffuse irreversibly into the metal. For a prescribed pressure loss through the filter, a maximum value is obtained for a quantity that is equal to the filter length in the direction of gas flow times the second Stanton number divided by the hydraulic diameter, the latter term being equal to four times the volume of the space in the cylinder not occupied by the filter material divided by the surface of the filter material in contact with the gas. Favorable filter escape coefficients are made available with relatively low pressure drop, so that the filter can be disposed in the main cooling gas line of a nuclear reactor for removing contaminants as radioactive caesium.
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