Constant concentration at the UF membrane wall UF process control and apparatus
AssigneeEastman Kodak Company
InventorsMargaret B. Wilcox, William R. Gately, Raymond F. Hall
Life of this patent
Estimating the term…
Abstract
A method and apparatus for ultrafiltration, washing and concentration of photographic emulsion uses the Blatt Stagnant Film Theory using a gelatin-based mass transfer coefficient of the feed, gelatin concentration of the feed and a setpoint of a constant concentration at the ultrafiltration membrane wall. A useful permeate flow is achieved by varying the pump speed and membrane pressures.
Claims6
A process for concentrating, separating and purifying photographic emulsions from mixtures including impurities using a spiral wound UF membrane comprising the steps of:
- (a) determining the constant concentration of gelatin at the spiral wound UF membrane wall;
- (b) determining a mass transfer coefficient of the photographic emulsion;
- (c) prescribing a wash conductivity endpoint and prescribing emulsion concentration endpoints;
- (d) circulating photographic emulsion from a reaction vessel through the spiral wound UF membrane at a constant gelatin concentration at the wall of the spiral wound UF membrane using a feed pump;
- and
- (e) updating a permeate flowrate from the spiral wound UF membrane, the speed of the feed pump, and the inlet pressure and outlet pressure of the spiral wound UF membrane as the volume decreases in the reaction vessel to achieve the constant concentration of gelatin at the spiral wound UF membrane wall until the wash conductivity and concentration endpoints are reached.
A process for concentrating, separating, and purifying photographic emulsions from mixtures including impurities using a spiral wound UP membrane comprising the steps of:
- (a) determining the constant concentration of gelatin at the spiral wound UF membrane wall;
- (b) determining a mass transfer coefficient of the photographic emulsion;
- (c) prescribing a wash conductivity endpoint and prescribing emulsion concentration endpoints;
- (d) circulating photographic emulsion from a reaction vessel through the spiral wound UF membrane at a constant gelatin concentration at the wall of the spiral wound UF membrane;
- and
- (e) maintaining the constant concentration of gelatin at the spiral wound UF membrane wall until the wash conductivity and concentration endpoints are reached by controlling a variable permeate flowrate from the spiral wound UF membrane as the volume decreases in the reaction vessel.
Dependencies are inferred from the claim text.