Improvement of Medium Flowrate Filters.

摘要

A research effort was undertaken for the development of a high-purity, high-efficiency, dualpurpose filter medium. The filter that was developed possesses the following characteristics: (1) High purity - 150 ppm impurities; (2) Medium flowrate - 34 cfm; (3) Efficiency for particulates - 95%; ( 4) Efficiency for elemental iodine 99.5%; (5) Both particulate and iodine stages can be destroyed in a wet oxidizing solution consisting of HNO3-HC104. The particulate filter is made of Fortisan fibers. A 4 in.-diameter filter disc weighs approximately 3.5 grams. The iodine filter is made of activated carbon fibers. The weight of this filter is approximately 2 grams. The final filter is a laminate of Fortisan and carbon fibers with a cheesecloth separator. It has been fabricated in the form of 4 in.-diameter discs which can be used in the Staplex Hi-Volume Air Sampler or the MSA FixtFlow Air Sampler. The two filters can be physically separated to facilitate radiochemical anslysis. (Author)