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US 5,626,023 AGranted
Cryogenic rectification system for fluorine compound recovery using additive liquid
AssigneePraxair Technology, Inc.
InventorsTheodore F. Fisher, Yijian Jin
Life of this patent
Estimating the term…
Abstract
A cryogenic system for the recovery of fluorine compounds from a carrier gas stream such as an effluent stream from a semiconductor facility comprising combining the carrier gas feed stream with additive liquid to keep fluorine compounds from solidifying and to reduce the vapor pressure of the fluorine compounds, followed by separation and recovery using a cryogenic rectification column system.
Claims20
A method for recovering fluorine compounds comprising:
- (A) combining a gaseous feed comprising carrier gas, high volatility fluorine compounds and low volatility fluorine compounds with additive liquid to form a mixed stream;
- (B) partially condensing the mixed stream to produce vapor comprising carrier gas and additive liquid comprising high volatility and low volatility fluorine compounds;
- (C) passing the additive liquid comprising high volatility and low volatility fluorine compounds into a first rectification column as first column feed and separating the first column feed within said first rectification column by cryogenic rectification into top vapor comprising high volatility fluorine compounds and additive liquid comprising low volatility fluorine compounds;
- (D) withdrawing top vapor comprising high volatility fluorine compounds from the first rectification column and recovering at least a portion thereof as product fluorine compounds;
- (E) passing additive liquid comprising low volatility fluorine compounds into a second rectification column as second column feed and separating the second column feed within said second rectification column by cryogenic rectification into top vapor comprising low volatility fluorine compounds and residual additive liquid;
- and
- (F) withdrawing top vapor comprising low volatility fluorine compounds from the second rectification column and recovering at least a portion thereof as product fluorine compounds.
4 more elements
Apparatus for the recovery of fluorine compounds comprising:
- (A) means for combining additive liquid with gaseous feed comprising fluorine compounds to produce a mixed stream;
- (B) a heat exchanger and means for passing the mixed stream through the heat exchanger;
- (C) a first rectification column and means for passing liquid from the heat exchanger into the first rectification column;
- (D) means for recovering fluorine compounds taken from the upper portion of the first rectification column;
- (E) a second rectification column and means for passing liquid from the lower portion of the first rectification column into the second rectification column;
- and
- (F) means for recovering fluorine compounds taken from the upper portion of the second rectification column.
4 more elements
A method for recovering fluorine compounds comprising:
- (A) combining a gaseous feed comprising carrier gas and fluorine compounds with additive liquid to form a mixed stream;
- (B) partially condensing the mixed stream to produce vapor comprising carrier gas and fluorine compound-containing additive liquid;
- (C) passing the fluorine compound-containing additive liquid into a rectification column as column feed and separating the column feed within said rectification column by cryogenic rectification into fluorine compound-containing top vapor and bottom additive liquid;
- and
- (D) withdrawing fluorine compound-containing top vapor from the rectification column and recovering at least a portion thereof as product fluorine compounds.
2 more elements
Apparatus for the recovery of fluorine compounds comprising:
- (A) means for combining additive liquid with gaseous feed comprising fluorine compounds to produce a mixed stream;
- (B) a heat exchanger and means for passing the mixed stream through the heat exchanger;
- (C) a rectification column and means for passing liquid from the heat exchanger into the rectification column;
- and
- (D) means for recovering fluorine compounds taken from the upper portion of the rectification column.
2 more elements
Dependencies are inferred from the claim text.