Methods and systems for characterizing a sorbent tube
AssigneePerkinElmer LAS, Inc.
InventorAndrew Tipler
Life of this patent
Estimating the term…
Abstract
Disclosed are systems and methods that include providing a vessel having an adsorbent disposed therein, the vessel having an inlet and an outlet for communicating a carrier gas through the vessel; determining a differential pressure between the inlet and the outlet for a known flow rate at the outlet; and, determining a geometric measure for the vessel based on a ratio of the known flow rate and the differential pressure. In some embodiments, the methods and systems can include a viscosity in the ratio, determining a flow rate at ambient pressure using a factor based on a ratio of a gas pressure at the output and ambient pressure, and/or, determining a flow rate at ambient temperature using a factor based on a ratio of a temperature at the output and ambient temperature.
Claims21
A method, comprising:
- providing a vessel having an adsorbent disposed therein, the vessel having an inlet and an outlet for communicating a carrier gas through the vessel;
- determining a differential pressure between the inlet and the outlet for a known flow rate at the outlet;
- and,
- determining a geometric measure for the vessel based on a ratio of the known flow rate and the differential pressure.
A chromatographic system, comprising:
- a carrier gas inlet for supplying carrier gas;
- a chromatographic column for receiving the carrier gas;
- a flow path through which the carrier gas is communicated from said carrier gas inlet to said chromatographic column;
- a vessel disposed in said flow path, said vessel having an adsorbent disposed therein for adsorbing and desorbing analytes to be measured;
- wherein said vessel includes an inlet and an outlet for communicating the carrier gas through said vessel;
- at least one sensor in communication with said flow path adjacent at least one of the vessel inlet and vessel outlet for measuring either the pressure drop or the flow rate of the gas communicated through said vessel;
- at least one computer connect to said sensor;
- software executing on said computer for comparing the measured pressure drop or flow rate to the expected pressure drop (pi−po) or expected flow rate Fa, respectively, of the gas communicated through said vessel calculated in accordance with the equation
- F
- a
- =
- k
- ·
- (
- p
- i
- -
- p
- o
- )
- η
- ·
- p
- o
- p
- a
- ·
- T
- a
- T
- o
- where pa is the ambient absolute pressure, Ta is the ambient absolute temperature, po is the absolute gas pressure at the tube outlet, To is the absolute temperature at the tube outlet, and k is the permeability factor of said vessel.
A method of performing a chromatographic analysis, the method comprising:
- providing a carrier gas inlet for supplying carrier gas;
- providing a chromatographic column for receiving the carrier gas;
- providing a vessel having an adsorbent disposed therein for adsorbing and desorbing analytes to be measured, the vessel having an inlet and an outlet for communicating carrier gas through the vessel;
- communicating carrier gas from the carrier gas inlet, into the vessel through the vessel inlet, and out of the vessel through the vessel outlet;
- measuring either the pressure drop or the flow rate of the gas communicated through the vessel;
- and
- comparing the measured pressure drop or flow rate to the expected pressure drop (pi−po) or the expected flow rate Fa, respectively, of the gas communicated through said vessel calculated in accordance with the equation
- F
- a
- =
- k
- ·
- (
- p
- i
- -
- p
- o
- )
- η
- ·
- p
- o
- p
- a
- ·
- T
- a
- T
- o
- where pa is the ambient absolute pressure, Ta is the ambient absolute temperature, po is the absolute gas pressure at the tube outlet, To is the absolute temperature at the tube outlet, and k is the permeability factor of said vessel.
Dependencies are inferred from the claim text.