US 6,599,369 B2Granted

Method of treating contaminated HEPA filter media in pulp process

AssigneeBachtel BWXT Idaho, LLC

InventorsJian S. Hu, Mark D. Argyle, Ricky L. Demmer, Emilio P. Mondok

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Abstract

A method for reducing contamination of HEPA filters with radioactive and/or hazardous materials is described. The method includes pre-processing of the filter for removing loose particles. Next, the filter medium is removed from the housing, and the housing is decontaminated. Finally, the filter medium is processed as pulp for removing contaminated particles by physical and/or chemical methods, including gravity, flotation, and dissolution of the particles. The decontaminated filter medium is then disposed of as non-RCRA waste; the particles are collected, stabilized, and disposed of according to well known methods of handling such materials; and the liquid medium in which the pulp was processed is recycled.

Claims20

Dependent claims

A method for reducing contamination with radioactive and hazardous materials of a HEPA filter comprising a filter medium and housing in which the filter medium is contained comprising:

removing loose particles and solids from the HEPA filter;
removing the filter medium from the housing;
decontaminating the housing;
and
after removing the filter medium from the housing, processing the filter medium in a liquid medium for removing trapped particles;
disposing of the filter medium from which the particles have been removed as non-hazardous waste;
collecting the particles from the liquid medium, stabilizing the collected particles, and disposing of the stabilized particles;
and
recycling the liquid medium after the particles are collected therefrom repelling the loose particles and solids and collecting them in a collection vessel.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/791,952Filed 23 Feb 2001
Published: US 2003/0041874 A16 Mar 2003
Granted: 29 Jul 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B01D 46/0094
Including arrangements for environmental or personal protection: against radiation
B01D 46/50
Auxiliary equipment or operation thereof: means for discharging electrostatic potential
B01D 46/66
Filters or filtering processes specially modified for separating dispersed particles from gases or vapours: regeneration of the filtering material…
B08B 3/12
With additional treatment of the liquid or of the object being cleaned, e.g. by heat, by electricity or by vibration: by sonic or ultrasonic…