tool for the in situ integrity testing of hydrophobic filters. During the test, the filter housing is submerged with water and automated devices provide an estimate of the evaporated water flow rate across the filter, i.e., water intrusion rate (WIR).WIR is generally correlated to the filter’s bacterial retention rate. Commercially available WIT devices differ with regard to the technique used to measureWIR. In this paper, we investigated the capacity of a pressure-decay batch device and a refilling continuous-flow device to provide reliable measurements of WIR at various WIRs and initial gas volumes above the filter. Experiments were performed with a model filter system simulating typical conditions of WITs and with a full-scale commercial filter. The pressure-decay batch device consistently underestimated the actualWIR. The error increased with decreasing initial gas volumes above the filter and with increasing actual WIRs. Measured WIR values were as much as 25% and 31%lower than the actualWIR for the model filter system and the full-scale filter, respectively. The refilling continuous-flow device yieldedWIR measures in excellent agreement with the actualWIRs with both the model filter system and the full-scale filter, independently of the WIR value and the initial gas volume above the filter.

Automated Integrity testing of hydrophobic filters based on water intrusion measurements: comparative analysis of a refilling Continuous-flow and a pressure-decay batch device

G. Catapano
2000-01-01

Abstract

tool for the in situ integrity testing of hydrophobic filters. During the test, the filter housing is submerged with water and automated devices provide an estimate of the evaporated water flow rate across the filter, i.e., water intrusion rate (WIR).WIR is generally correlated to the filter’s bacterial retention rate. Commercially available WIT devices differ with regard to the technique used to measureWIR. In this paper, we investigated the capacity of a pressure-decay batch device and a refilling continuous-flow device to provide reliable measurements of WIR at various WIRs and initial gas volumes above the filter. Experiments were performed with a model filter system simulating typical conditions of WITs and with a full-scale commercial filter. The pressure-decay batch device consistently underestimated the actualWIR. The error increased with decreasing initial gas volumes above the filter and with increasing actual WIRs. Measured WIR values were as much as 25% and 31%lower than the actualWIR for the model filter system and the full-scale filter, respectively. The refilling continuous-flow device yieldedWIR measures in excellent agreement with the actualWIRs with both the model filter system and the full-scale filter, independently of the WIR value and the initial gas volume above the filter.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11770/275298
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