Predicting logarithmic reduction values
AssigneeUSF Filtration and Separations Group, Inc.
InventorsMichael R. L. Selbie, Humphrey J. J. Drummond, Warren T. Johnson
Life of this patent
Estimating the term…
Abstract
A method of predicting logarithmic reduction values for a membrane filtration system having a filtrate flow portion and a bypass flow portion relative to a filtrate permeable membrane with stable input gas flow comprising: determining the filtrate flow rate through the membrane under the action of an applied test pressure, determining the membrane bypass flow rate using integrity test measurements and estimating the logarithmic reduction value using the ratio of determined filtrate flow rate and determined bypass flow rate. Methods of testing the integrity of a porous membrane are also disclosed.
Claims4
A method of predicting a logarithmic reduction value for a membrane filtration system, the membrane filtration system having a membrane, the membrane having a bubble point, a first side, and a second side, and the logarithmic reduction value being defined by the formula:
- LRV = log 10 ( C inf C eff ) ( 1 )
- wherein LRV is the logarithmic reduction value, Cinf is a concentration of particle in an influent, and Ceff is a concentration of particle in an effluent, the method comprising the following steps:
- (i) measuring a flow rate of liquid filtrate through the membrane;
- (ii) measuring a membrane bypass flow rate using an integrity test measurement, wherein the membrane bypass flow rate is the flow rate through leaks and defects in the membrane;
- and
- (iii) estimating the logarithmic reduction value using a ratio of the filtrate flow rate and the membrane bypass flow rate as follows:
- LRV est = log 10 ( Q filt Q bypass ) ,
- wherein LRVest is an estimate of the logarithmic reduction value, Qfilt is the filtrate flow rate, and Qbypass is the membrane bypass flow rate.
Dependencies are inferred from the claim text.