Containers for Fluids with Composite Agile Walls

Abstract

The disclosure is directed to sampling bags having flexible walls. The sampling bags may have agile walls that include a shape memory component. The shape memory component tends to return the sampling bag to its initial shape. Such sampling bags may be used in a variety of sampling methods.

Description

FIELD OF THE INVENTIONEmbodiments of the invention relate to containers for fluids, and more particularly to fluid containers comprising agile walls. The agile walls comprise a component with a shape memory that tends to return the fluid container to an initial shape. The sampling bags may be used for environmental sampling for industrial hygiene applications, for example.BACKGROUND OF THE INVENTIONConventional containers for fluids may have rigid walls or flexible walls. Containers with rigid walls have a defined permanent volume for containing fluids and containers with flexible walls have variable or changeable volumes. Conventional containers include, but are not limited to, bottles, canisters and bags. Such containers may be used for a variety of purposes, including obtaining and holding fluid samples and containing standard gas mixtures that may be used for calibration of analytical instruments. As used herein, the term “fluid” includes gases and / or liquids. There are many con...

AI Technical Summary

Benefits of technology

The walls of the container may comprise multiple layers or components. A layer may be a complete layer covering the substantially the entire surface area of the bag wall or a partial layer covering only a portion of the bag. The layer may be made of expanded metal, metal wire, leaf springs or other such configuration have an appropriate shape and shape memory. The agile walls provide a built-in regeneratable source of energy.

Problems solved by technology

Any adsorbed residue or residual gas may contaminate any prepared fluid mixture or sample of fluid put in a poorly prepared bag.

The disadvantages of containers with rigid walls include their extremely high price and expensive maintenance; they are bulky and, thus, their storage, transportation, and mailing costs are expensive; they have to be over pressurized when delivery of gas vapors or mixtures is needed; and completely vacuumed before used for fluid sampling.

Another drawback of sampling with containers with rigid walls is that after removing a portion of the sample from the container, the pressure in the canister may be reduced below atmospheric pressure and additional carrier gas (noble gas for example) may be added to increase the pressure back to atmospheric pressure.

A small sampling pump cannot create a sufficient vacuum within the container; therefore, strong specialized vacuum pumps are needed.

There are advantages and disadvantages to using this method with sampling bags.

The disadvantages include the cost, inaccuracy, and potential contamination from using an external pump to deliver and withdraw the fluid mix.

The contamination or inaccuracy can occur from sorption and desorption of some chemicals or components of gas mixture or sample on the walls of the tubes, internal part of the pumps, filters, tubing and connectors.

The same problem is caused by sorption of chemical components on the walls of the sampling bag.

The other drawbacks of the configuration of FIG. 8 are, however, still persisting in the alternative configuration of FIG. 9, for example, the components is bulky and heavy; the equipment is expensive; the pump requires a battery and frequent maintenance; the sorption on the walls of the bag is the same as described above.

Despite of cleanliness suggested by this method, it is using comparably heavy, bulky and expensive equipment requiring calibration and battery maintenance.

Further, the expandable means prevents full evacuation of the contents of the envelope.

Further, the envelope cannot be reused, because the sampling volume would need to be purged several times to clean the envelope, however, the self sealing septum of the envelope does not allow such a procedure.

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