HK1181014A - Container for fluid sampling with flexible metal alloy walls - Google Patents

Description

Container for fluid sampling with flexible metal alloy wall

Related application

This patent application claims priority from united states provisional patent application No. 61/308,502, filed 2/26/2010, in accordance with 35u.s.c. § 119, which is incorporated herein by reference in its entirety.

Technical Field

The present invention is directed to a container for a fluid. In a particular embodiment, the container may comprise a flexible wall, wherein the flexible wall comprises a metal alloy.

Background

Containers with fixed volume, such as but not limited to bottles and cans, or containers with variable volume, such as but not limited to flexible-walled bags, are used to prepare gas mixtures for laboratory use or sampling of gases or fluids.

Such containers may be used for industrial hygiene and safety sampling to determine gas concentrations in the environment or in processing equipment. To ensure accuracy and reliability, containers for sampling and/or containing gaseous and liquid substances have been specialized for specific uses. The container may be substantially gas impermeable (at least to the target compound), strong and resilient, having substantially inert interior wall surfaces, so that in some applications a fluid mixture or sample may be able to be stored for an extended period of time without significant change in the composition of the sampled or prepared mixture.

The fixed volume tank may have walls made of a metal such as a stainless steel alloy. The inner surface of the wall may be additionally treated, for example chemically polished and passivated, to reduce absorption of compounds or contamination of the contents. Disadvantages of fixed volume containers include high price, relatively high weight, bulkiness, and high transportation costs. Another disadvantage of fixed volume vessels arises from the maintenance and special preparation procedures required for them, including purging with noble gases, heating and then evacuating to extremely low pressures with a power laboratory pump to evacuate the previous fluid prior to use.

Handling of the sample is also difficult with fixed volume containers. Removing the sample from the fixed volume container results in a reduced pressure, or in some cases, a partial vacuum within the canister. In certain applications, additional carrier fluid must be added to compensate for the removed sample and the sample concentration must then be recalculated for accurate future use.

The gas mixture stored under pressure in a fixed volume vessel is used to make a standard fluid mixture in industrial quantities. Standard fluid mixtures typically include a relatively high concentration of one (or more) component in the carrier fluid. For laboratory use, for example in calibrating analytical equipment, it is possible to dilute such standards with additional carrier fluid to obtain the appropriate concentration for a particular application.

Due to the disadvantages of fixed volume containers, the most widely used containers for transporting, preserving and containing mixtures for laboratory or industrial hygiene use are containers comprising flexible walls. Typically, the flexible wall is made of an inert, low permeability material. The walls should have a low adsorption of the contained and/or target components on the walls. Containers having flexible, low permeability, low absorbency walls (e.g., sampling bags) are widely used for fluid sampling, air sampling, and liquid sampling. The sampling bag has walls that typically comprise materials such as Kynar (hexafluoropropylene-polyvinylidene fluoride) and Tedlar (modified polyvinyl fluoride).

In order to fill any of such containers with a sample or mixture, some preparation is required. The bag should be purged, followed by a rinse for desorbing any residue of the previous contents and its volume should be reduced to as small as practical, preferably substantially zero. Any adsorbed residues or residual contents may affect or contaminate future fluid mixtures or sample fluids.

The plastic materials used to make sampling bags have low but measurable permeability, and manufacturers typically disclose data that includes the permeability of sampling bags with different wall compositions. Permeability data is provided over a certain time period relative to different fluid, mixture, and gas samples and can be determined experimentally. There are at least two processes occurring in the sampling bag that affect the concentration of the components when the fluid comes into contact with the inner wall of the bag, including adsorption on the wall of the sampling bag and diffusion through the wall of the sampling bag. For some low concentration samples, although low adsorptivity is claimed, the recovery of the sampled material may be only 85-90% of the sampled component, even shortly after the bag is loaded. These losses are mainly due to absorption at the wall and penetration through the plastic wall. While the walls may be cleaned or new, some of the possible adsorption sites are still functional on the bag walls.

To control the loss through gas permeation, different materials are used for different sampled species. Even materials such as Teflon (Teflon) and other fluorinated plastics have some measurable gas permeability.

Permeability may be reduced by using a sampling bag having walls comprising layers of different materials. Some multi-layer sampling bags comprise an aluminum foil sandwiched between a polyolefin layer and a polyester layer. Such pouches have exhibited significantly reduced, but still measurable, permeability for certain target compounds. To achieve good multilayer assembly and adhesion, some layers may include a low melting polymer, such as polyethylene. However, polyethylene can give off low concentrations of residual monomer, which contaminates the volume sampled. The sampling industry accepts and compensates for this lack of time stability of the sample and sample contamination within the sampling bag because the use of sampling bags is many times easier and less expensive than with more stable fixed volume containers. All sampling by flexible wall sampling bags is currently performed with a sampling pump.

There is a need for a sampling container that will have all the convenience of a sampling bag and the stability of sampling with a hard-walled can.

There is also a need for a sampling vessel that allows an operator to take samples by a direct grab method without the use of a mechanical pump.

Furthermore, there is a need for a convenient container that will allow self-sampling to be performed in a short or extended period of time.

Furthermore, there is a need for a multifunctional sampling fixture-sampling head that can be easily operated, for example by one hand, not only with an on/off function, but also allows for quick switching to different sampling modes, such as different nozzles, for introducing a fluid sample into a bag through a series of pneumatic resistances; sampling the bag contents directly or via a septum on the valve; and rapid fluid connection of the bag contents to other fluid analysis systems.

Disclosure of Invention

The present invention is directed to embodiments of containers having flexible walls and methods of forming such containers. Embodiments include a sampling bag comprising at least one flexible wall, wherein the flexible wall comprises at least one layer comprising a metal alloy. Embodiments further comprise an inlet. The inlet may comprise at least one of: an on/off valve, a flow control valve, a tube, a diaphragm, a tube connector, a flow restrictor, a tube connected to a pump, or other device needed to obtain a sample or deliver a fluid. Embodiments of the valve may include a quick disconnect connector and/or multiple inlets including shaped orifices to achieve different flow characteristics under the same flow conditions. Quick disconnect connectors may be used to attach a variety of different accessories to the valve.

The flexible wall may comprise at least one layer comprising a sheet of metal alloy. In some embodiments, the flexible wall may be composed of a sheet of metal alloy. In other embodiments, the flexible wall may consist essentially of a sheet of metal alloy. Other embodiments of sampling bags or containers having flexible walls may have additional layers or other components.

Embodiments of the container and sampling bag include a sheet of metal alloy that forms substantially the entire interior surface of the sampling bag. In such embodiments, there may be other materials on the inner surface, such as, but not limited to, sealing material around the periphery of the bag or around any inlets or other apertures in the wall.

In a more particular embodiment, the sampling bag comprises two flexible walls that are joined to form the sampling bag. The flexible wall may be hermetically sealed at a periphery of the interior volume to form a sampling bag.

Any metal alloy sheet that provides sufficient flexibility and impermeability to the sampled gas may be used. For example, the metal alloy sheet may have a thickness in the range of 10 to 100 micrometers or in the range of 25 to 50 micrometers to facilitate folding.

Embodiments of the present invention are also directed to methods of forming a container or sampling bag. An embodiment of a method of forming a sampling bag includes sealing the perimeters of at least two sheets of corrosion-resistant metal alloy to form the sampling bag, and providing access to a space between the two sheets. The sheets may be sealed by any method, including but not limited to, for example, welding two sheets, laser welding two sheets, gluing two sheets, folding and crimping a sheet with a gasket. After sealing, the perimeter of the sheet may include a seam, which may be 0.5 to 1.5mm wide.

Access to the space between the sealed sheets may be provided by forming apertures in at least one of the metal alloy sheets. The apertures may be formed by punching out apertures, cutting out apertures, or laser cutting out apertures, for example. The method of forming a sampling bag may further comprise installing a valve in the port. The orifice may be sealed by mounting the valve using a gasket.

Embodiments of the method of forming a sampling bag may further comprise passivating the space between the two sheets. Passivating the space between the two sheets can include adding an acid to the sampling bag. The acid may be, for example, nitric acid or citric acid, and is at any concentration effective to passivate the surface of the metal alloy, such as, but not limited to, a concentration of acid in the range of from 3% to 5%. After passivation, the interior of the bag may be dried. Drying the interior of the bag may comprise heating the bag to a temperature above 60 ℃ while simultaneously applying a vacuum to the interior of the bag, for example through an orifice; other drying methods may also be used. Chemical passivation of at least one interior surface on each of the sheets prior to sealing the perimeter may be performed with an acid.

Another embodiment of the present invention includes a sampling bag having a quick-opening sampling valve. The valve may include a base and a stem including a connector, wherein the valve opens when a longitudinal axis of the stem is oriented parallel to a longitudinal axis of the base and closes when the longitudinal axis of the stem is oriented perpendicular to a longitudinal axis of the base. The sampling valve may further comprise a quick disconnect connector capable of receiving a plurality of sampling accessories. The sampling accessory may include, but is not limited to, for example, a tubing connector, a septum retainer, or a portal including a calibrated pneumatic resistance. An inlet comprising a calibrated pneumatic resistance can be calibrated to at least partially fill a sampling bag in a time selected from 15 minutes, 30 minutes, one hour, two hours, four hours, eight hours, or twenty-four hours based on a typical differential pressure of the sampling bag and the environment to be sampled.

Another embodiment of a sampling valve can include a multi-position valve, wherein the multi-position valve includes at least two inlets and one three-position valve. Each of the inlets may comprise a different calibrated aerodynamic drag flow path, with each of the inlets calibrated for different flow rates under the same conditions.

Further embodiments of the multi-position sampling valve may include three selectable inlets, wherein each of the inlets is calibrated for different flow rates under the same conditions. For example, embodiments of a multi-position valve may include a rotatable turret for selectively opening the valve to one of the inlets or for closing the valve. The turret may be combined with a second valve, wherein the second valve is an on/off valve having two positions, one of which opens the valve and a second of which closes the valve, wherein the second valve comprises a base and a stem, wherein the second valve opens when a longitudinal axis of the stem is oriented parallel to a longitudinal axis of the base and closes when the longitudinal axis of the stem is oriented perpendicular to a longitudinal axis of the base.

Some materials, which are generally considered to be very hard but still breakable (cold brittle), can be fabricated as thin layers or sheets by other methods, thus becoming flexible and conformable. For example, some stainless steel alloys, such as SST 304, SST 309, SST 316L, SST 321, low carbon stainless steel, and nickel titanium alloys known as nitinol, have become available in somewhat thin, flexible sheets. Embodiments of the sampling bag of the present invention may include a wall comprising a flexible stainless steel alloy sheet. Additional embodiments of the sampling bag may include flexible nickel or titanium sheets.

The present invention is directed to the use of thin sheets of stainless steel or other highly corrosion resistant alloys for the sampling bag walls. Further embodiments are directed to methods for sealing such sampling bags having walls, comprising treating the inner and outer surfaces for different needs (sampling of different gases and mixtures). Bags made of stainless steel or such alloys can be durable, easily cleanable, and can be cleaned of any possible residue at elevated temperatures. Stainless steel or alloy bags may be a much cheaper alternative to cans and a much better alternative to plastic sampling bags, avoiding both of the already mentioned inherent disadvantages. On the other hand, there is no experience or suggestion of manufacturing sampling bags from sheet metal within many of the technical limitations of this process.

The present invention is also directed to the design of a sampling bag that allows sampling without the need for a pump by using a hand-held side panel and/or by a spring that includes a passageway to open the bag to create an under pressure that will push the sampled fluid inside.

The present invention is also directed to a sampling bag comprising an inlet/outlet capsule allowing an on/off function, a flow path for short and/or long term sampling, and a septum for sample extraction.

Other aspects and features of embodiments of sampling bags comprising metal alloys will become apparent to those ordinarily skilled in the art upon review of the following description of specific exemplary embodiments of the invention in conjunction with the accompanying figures. Although features may be discussed with respect to certain embodiments and figures, all embodiments may include one or more of the features discussed herein. Although one or more particular embodiments may be described herein as having certain advantageous features, each of such features may also be integrated into various other features of the embodiments of the invention discussed herein (except where such integration is incompatible with other features of the described embodiments). In a similar manner, although exemplary embodiments may be described below as system or method embodiments, it should be appreciated that such exemplary embodiments may be implemented in a variety of systems and methods.

Drawings

FIG. 1 depicts an embodiment of a sampling bag having two flexible walls, the walls comprising layers of metal alloy sheets; FIG. 1a shows the sampling bag in a flattened state substantially without an internal volume, and FIG. 1b shows the sampling bag in a filled or loaded state;

FIG. 2A depicts a side wall and seam cross-section, wherein FIG. 2A-a shows an embodiment of a sampling bag having a wall comprising a single piece of a metal alloy, the piece having a seam welded without margin; 2A-b show an embodiment of a sampling bag comprising a wall of a single sheet of metal alloy, the sheet being resistively welded with seams and having some protruding material; 2A-c show one side of a sampling bag with a sheet of thermally laminated metal alloy, the sheet being heat sealed in a plastic-to-plastic manner with additional tape over the seam; FIGS. 2A-d show an embodiment of a sampling bag having an outer surface heat laminated with a sheet of metal alloy (heat sealed); 2A-e show an embodiment of a sampling bag with two sides of a sheet of heat laminated metal alloy with fluorocarbon material on the inside and additional material on the seams on the outside; 2A-f show two sides of a metal alloy sheet having two plastic sheets with a thermal seam; 2A-g show an embodiment of a sampling bag comprising an outside laminated metal alloy sheet with a fluorocarbon gasket protruding into the seam; 2A-h show an embodiment of a sampling bag comprising a metal-to-metal seam formed by overlapping materials and folding one sheet over the other and heat laminating after sealing;

FIG. 2B, which includes FIGS. 2B-a and 2B-B, depicts cross-sections of two embodiments of a sampling bag, where FIG. 2B-a shows a design comprising two (or more) fluidly interconnected chambers, and FIG. 2B-B depicts a bag comprising walls, concentric corrugations of the surfaces of the two walls meshing congruently when the bag is empty;

FIG. 3 shows an embodiment of a sampling bag comprising a wall comprising a metal alloy sheet with side panels comprising a rigid panel with a collapsible handle overlapping the perimeter of the bag and a partial panel with a soft handle, FIG. 3-a shows a perspective view of the bag with the handle, FIG. 3-b shows a perspective view with the handle joined;

FIG. 4 shows an embodiment of a sampling bag comprising a wall having a metal alloy sheet, the bag having side panels and a handle in the shape of a strip, FIG. 4-a showing an initial position of handle engagement; FIG. 4-b shows the handle pulled out and the sampling bag filled;

FIG. 5 shows a perspective view of a sampling bag filled with a sample, with inlet 27 closed ready for mailing or analysis; FIG. 5-a shows a sampling bag with overlapping panels and a pre-cut handle; FIG. 5-b shows a sampling bag with a small panel (smaller than the size of the wall) and a soft handle;

FIG. 6 shows a perspective view of a sampling bag (metal alloy bag) having walls comprising a flexible metal alloy sheet, with the side panels pushed out by a spring for self-sampling, and the sampling head having an optional inlet or diaphragm with a pneumatic resistance;

FIG. 7 shows a sampling valve with a basic multi-functional sampling head (with on/off functionality) and a sampling attachment, wherein the sampling attachment may include a sampling tube with optional pneumatic resistance, a diaphragm, optional pneumatic resistance mounted on a rotatable and fluidly interconnected turret, ready for sampling by calibrated capillary tubes mounted on the rotating turret;

FIG. 8-A shows an embodiment of a sampling head or valve that can be opened by rotating the valve stem 90 to an off position and returning 90 to an on position, with the capillary fluid on the turret disconnected and the quick connect socket connected to a semi-hard pipe; FIG. 8-B shows an embodiment of a sampling head or valve rotated 90 to an "off" position, with capillary fluid off the turret and a barb tube connector inserted into the quick connect socket; and

fig. 9 shows an embodiment of a sampling bag comprising a quick disconnect coupling attached to a flow nozzle comprising a calibrated pneumatic resistance for customizing the sampling time.

Detailed Description

The present invention is directed to improvements in containers having flexible walls and sampling bags. The present invention is directed to a sampling bag for holding laboratory standards, industrial hygiene samples, or other gases or liquids. In one embodiment, the sampling bag comprises at least one flexible wall. A sampling bag having flexible walls can be inflated or deflated to increase or decrease the internal volume of the sampling bag. Embodiments of the sampling bag include at least one flexible wall comprising at least one layer comprising a metal alloy. In certain embodiments, the metal alloy is a metal alloy sheet on an inner layer of a wall of the sampling bag. The layer comprising the metal alloy may be a sheet of the metal alloy.

As shown in fig. 1a and 1b, a typical embodiment of a sampling bag will comprise two flexible walls, wherein each flexible wall comprises at least one layer of a metal alloy sheet. Embodiments of the sampling bag include an enclosure comprising at least one flexible wall and an inlet, wherein the flexible wall comprises at least one layer of a metal alloy sheet. The flexible wall comprising a metal alloy allows the sampling bag to have a variable volume, similar to sampling bags having plastic walls, and the layer comprising or consisting of a metal alloy provides the sampling bag with low permeability and absorbency of a fixed volume metal container. Embodiments of the sampling bag may comprise or consist of two flexible walls, wherein each flexible wall comprises at least one layer comprising or consisting of a sheet of metal alloy. In such embodiments, the two flexible walls may be joined together, directly or indirectly, to form a sampling bag. In such embodiments, both sides of the sampling bag may be expanded to increase the volume of the sampling bag, and then compressed to reduce the volume back to substantially zero to vent most of the gas within the expanded sampling bag. In this way, the sampling bag can be easily cleaned and prepared for use.

A sheet of metal alloy may be used to form the layer of the flexible wall. The metal alloy sheet may be any shape including, but not limited to, rectangular, square, rectangular, oval, cylindrical, folded shapes (e.g., accordion shapes or other folded shapes), or a combination of shapes. Some shapes may be more advantageous for certain applications because the shape may be more conducive to the sampling bag being compressed to a minimum volume, thus evacuating a substantial portion of the residual sample of the sampling bag that was previously used. The layers making up the metal alloy walls may be flat, corrugated, channeled, folded or otherwise configured to facilitate inflation and deflation.

The layers of the metal alloy sheet can be any desired thickness having the properties desired for a particular application. These properties include strength, flexibility, permeability, elasticity, and other desirable properties. In some embodiments, the metal alloy layer may have a thickness in a range of 1 micron to 100 microns. In other embodiments, the metal alloy layer may have a thickness in a range from 20 microns to 60 microns, or from 25 microns to 50 microns. If desired, the flexible wall may comprise more than one sheet of metal alloy having similar or different thicknesses that provide a combination of desired properties.

As used herein, a "metal alloy" can be any metal comprising a pure metal or a combination of different metals. The metal alloy may be any metal alloy having the desired properties of strength, flexibility, elasticity, permeability, and absorbency. In some embodiments, the metal alloy may be, but is not limited to, a stainless steel alloy such as SST 304, SST 309, SST 316L, SST 321, a low carbon stainless steel, nitinol, nickel, or titanium. Other metal alloys having the desired properties may also be used in embodiments of the present invention. For example, the layers of the flexible wall may consist essentially of flat stainless steel sheets or corrugated stainless steel sheets. The properties of the metal alloy sheet are sufficient if the sampling bag can be inflated and deflated at least once.

Further, the Sampling bag may include a faceplate attached, or otherwise connected to the flexible wall, as described in pending patent applications entitled "Device for Fluid Sampling" and "container for Fluid with Composite Agile Walls" filed on day 16, 2.2011 by the same inventors. A relatively simple-to-use embodiment of the sampling bag may include two flexible walls, where each wall includes a panel attached to an outer surface of the wall. The panel may comprise any material that is capable of being adhered to a wall and pulled to inflate a sampling bag or compressed to deflate a sampling bag. For example, the panels may comprise a material selected from, for example, cardboard, corrugated paper, or corrugated board. The sampling bag may further comprise a spring capable of biasing the panels apart from or toward each other to urge the sampling bag to an initial shape.

As seen in fig. 1a and 1b, the embodiment of the sampling bag 10 having a metal alloy wall 12 is generally rectangular in shape. As shown, the corners of the bag may be rounded or beveled in order to avoid the presence of fluid residue in the corners. For certain embodiments of rectangular sampling bags, the seam should be as close to the perimeter as possible to limit the amount of excess material. Excess material beyond the seam may result in undesirable (in some applications) reduction in rigidity, flexibility of the bag or the creation of stress points when the sampling bag is loaded. Embodiments of sampling bag 10 comprising a metal alloy wall may have a slightly reduced capacity compared to a similarly sized sampling bag having a wall segment plastic wall of the same size. The size of the metal alloy wall can be increased or decreased to adjust the inflated volume of the sampling bag.

As with other sampling bags, excessive edge material and excessive inflation of the sampling bag can cause wrinkling of the sidewall. Wrinkles may create tension at localized points (stress points) in the seam and accelerate wear of the bag. One advantage of sampling bag 10 comprising flexible walls comprising a metal alloy as compared to a plastic bag is that the sheet of metal alloy is substantially impermeable to the walls and is capable of storing samples for extended periods of time. For example, a sample may be stored several times longer than any plastic sampling bag. Bags made of metal alloys can last tens of times longer than plastic-walled sampling bags and bring about significant overall efficiency. The pouch has advantages over solid wall cans in terms of its weight, size, small volume, less labor intensive use, and low cost of mailing. Embodiments of sampling bags with metal alloy walls combine the advantages of plastic sampling bags with fixed volume metal containers without disadvantages.

Additional embodiments may include a method of forming a sampling bag. Embodiments of a method for forming a sampling bag may include at least one of the following steps, which are not presented in a particular order. The thin metal alloy sheet of wall 12 of sampling bag 10 may be sealed by a variety of methods. The metallic alloy wall of the sampling bag may be subjected to chemical polishing, especially on the inside of the wall. The chemical polishing can be performed by any known method, for example by treating the wall with a reactant based on a mixture of hydrochloric acid, nitric acid and hydroxybenzoic acid in the presence of a cationic surfactant and a ferricyanide complex for 6 to 12 hours, for example at 35 to 50 ℃.

A further step may be chemical passivation of the inside of the flexible wall. Chemical passivation can be performed by contacting the inner wall with at least 3% citric acid at 50 ℃ for 2 hours.

In addition, another step may include cutting the plurality of metal alloy sheets. For example, one method may include cutting two similarly sized rectangular sheets of thin metal alloy for the wall. A combination of these steps can be used to form an extremely smooth, thin and chemically stable layer on the inner surface of the metal alloy. Possible additional steps include cutting an aperture in at least one of the metal alloy sheets. For example, one of the metal alloy sheets may be punched to form an aperture having dimensions capable of receiving the base of an appropriate sampling head clamp 27 or other sampling valve or diaphragm. The base of the clamp 27 can be securely mounted in the aperture by using, for example, a gasket 11 to ensure air tightness. The mount may be permanently mounted using an adhesive. Yet an additional step may include cutting one sheet of metal alloy such that it overlaps another wall, such as in the case of a mounted clip 27. The two sheets can then be sealed together, for example, by adhesives, gaskets, mechanical clamping, laser welding, resistive welding around the perimeter in a seam, other sealing methods, or a combination of sealing methods. The seam on the edge of the sampling bag produced by the welding process may be, for example, 0.5-1.5mm wide.

It may be desirable that the clamp 27 be removable from the sample. For example, the clamp 27 may include a removable upper piece that will provide access to the interior space of the sampling bag. A possible further step to make the sampling bag may be to passivate the inside area of the seam after bag formation by removing the clamps 27 and adding a passivating chemical. Laser welding resistive welds or other thermally-associated sealing techniques may result in the formation of colored oxides on the walls. The cleaning or passivation may be performed with nitric acid or citric acid solutions by adding acid solutions or filling the bag substantially to the top with solutions for the time necessary for the procedure for passivation. For example, passivation may be performed by contacting a 3-10% acid solution with the metal alloy for more than 2 hours. The passivation time may depend on several factors, including the degree of oxidation of the joint during the sealing or other process. After the seam is deactivated, the bag may be dried to remove the residue. Drying of the interior space of the sampling bag may be performed by conventional means, for example by heating the bag in a vacuum oven at a temperature elevated to 100 ℃ or any other means. The top part of the clamp 27 can be replaced if it is removed in any previous step or has not been installed.

In addition, the sampling bag can be tested for leaks. Leaks may exist in the joint and around the gasket 11. The leak test may be performed by any known method, such as, but not limited to, a foam-bubble method or a pressure test. In certain embodiments, the sampling inlet 27 may be fabricated from a material that is stable at high temperatures, e.g., similar to PTFE, FEP, Delrin @^TM(Acetal), PTFE filled Delrin-AF^TMEtc., or made of a metal alloy, such as titanium or stainless steel. All components exposed to the interior volume of the sampling bag are made of the same material or materials having similar properties (e.g., permeability, composition, and/or absorption properties). For example, in the case of drying or purging the bag assembly 10 with pure nitrogen or pure air at an elevated temperature of about 200 ℃, the metal valves in the sampling bag will not be adversely affected. Similar temperatures may be applied to purge and evacuate the laser sealed bag after use.

Fig. 2A-a show a cross-section of a seam on an embodiment of a sampling bag. Sampling bag 10, made solely of metal alloy sheet wall 12, may have sharp edges including corners and sharp edges along the wall seams. For this reason, the material of the wall can be laminated on the outside with a plastic layer or partial layer, in order to ensure safety properties or for other reasons. The plastic layer may have charge dissipative properties. This process may include cold lamination using a silicon adhesive laminate or hot lamination using an appropriate material. In certain embodiments, the laminate may have a rather high thermal stability to thereby withstand relatively high temperatures in case of purging the inside volume with certain Volatile Organic Compounds (VOCs) having a higher boiling point, e.g. the plastic material is thermally stable at 100 ℃ as well as above 100 ℃.

In embodiments with cold lamination, materials such as thin vinyl can be used with a strong acrylic adhesive if sampling of high boiling point VOCs is not expected. Fluorocarbon compounds as thin as 1 to 4 mil sheets laminated with silicon-based adhesives are more preferred because bags laminated in this manner can be heat treated up to 200 ℃ without losing any of the sealing properties of bags used with other plastics or adhesives. Fluorocarbon and silicone adhesives do not leak gas, which can be another important feature so that they do not contaminate the sampled fluid with gas leaks. The laminate may protrude 6-12mm beyond the metal alloy sheet to ensure good adhesion between the two surfaces. The margin of protrusion will be flexible and may not lead to the formation of wrinkles. Fig. 2A-b show cross-sections of such a seam.

Another method of manufacturing the bag is from a metal alloy sheet that is initially cleaned and passivated and then laminated from one or both sides. The process is different when laminating one side. If one side is laminated, the laminate may protrude 8-15mm outward from each side. In such embodiments, the metal alloy sheets should overlap, which can be easily controlled by viewing through transparent or translucent laminates or by mechanical means.

Additional steps that may be added to the method of forming the sampling bag may include heat sealing the walls of the sampling bag. The inside of an embodiment of the sampling bag may comprise or consist of a metal alloy sheet 12 and the outside may be a plastic laminate 14, as shown in fig. 2A-d. In this step, the jaws of the heat sealing tool may overlap a portion of the metal alloy material and protrude outward to heat seal the plastic. After heat sealing, the seam cross-section may look as shown in fig. 2A-c. In this embodiment without a direct seal to the metal alloy sheet, the fluid in the fully loaded bag may be in contact with the area of plastic material in the seam. The contact surface of the plastic material of the outer laminate on the inside of the sampling bag is relatively small compared to the surface area of the metal alloy wall. Thus, any diffusion of the fluid component through the laminate is highly unlikely due to the distance between the inside contact via the laminate and the outside environment. The thickness of this seam can be increased by adding a strip from the seam or thicker material on the edge of the wall in the seam area, as shown in fig. 2A-d. This type of seam is inexpensive and further supports the seam against damage due to overpressure.

For further embodiments of the sampling bag, such as those used in the sampling of invasive sulfur-containing compounds, the inside of the seam of the bag may also be laminated by a fluorocarbon layer 14. In some embodiments, such a laminate 14 may be completed such that the laminate extends 0.5-1mm past the edge of the metal alloy sheet 12, and then the outer surface is heat laminated or sealed by other means 13. Fig. 2A-e show cross sections of such a seam assembly. In some embodiments, the plastic material extends over the sheet and is heat sealed. The layer added to the inner side of the metal alloy wall may also comprise other plastic materials. The inner layer may be inert but slightly permeable to the component being sampled, in this embodiment the metal alloy wall provides impermeability to the combined wall.

To avoid exposure of the wall edges 18 (without special treatment) when the inside of the wall 12 is not laminated as described, gasket strips, such as fluorocarbon gaskets, may be introduced in the seams, as shown in fig. 2A-f. Bags comprising fluorocarbons with cold seams comprising silicon adhesives can withstand temperatures of up to 180-200 c. Other embodiments can be heated to 80 ℃ without loss of properties. These temperatures may be reached when the bag is heated and evacuated for, for example, cleaning and cleaning or for hot gas sampling.

Another means for sealing the sheet of metal alloy to form the bag is to mechanically seal the bag, for example by folding the sheet of metal alloy 12 once or twice to form a seam 21. The silicon adhesive may be introduced in the fold region prior to folding. The folded seam is shown in fig. 2A-h and may be more rigid and less flexible than other sealing methods due to the multiple metal alloy layers. The rigidity may cause wrinkles on the side seams and walls and some tension in the corner points when inflated. These embodiments may also include additional layers 14.

To avoid deep wrinkles in the flexible wall that may cause material fatigue at stress points formed at the ends of the wrinkles. As already mentioned, the metal alloy bag should be filled with a smaller volume than a plastic bag having the same outer dimensions. As shown in fig. 2B-a, having a bag with two or more interconnected chambers is a preferred method to avoid deep wrinkles. The cross-section of the embodiment in fig. 2B-a is shown at low and fully inflated volumes so as to make visible the walls in the flattened bag that are very close and inseparable for viewing.

2B-B depict another embodiment, in which the two walls of the sampling bag are corrugated, with the grooves and ridges in generally concentric circles. This corrugation allows the wall to be "stretched" well beyond the allowable position for flattening the wall shown in fig. 1, and no wrinkles are formed. In the flattened bag, the walls are congruent engaged and one wall is shown in phantom. It can be seen in fig. 2B that after stretching, the grooves and ridges are becoming shallower and the stretching of the sinusoidal surface is longer than in the initial case shown in the middle of fig. 2B-B. The corrugating may be performed by rolling a pipe or press forming, for example.

There are a variety of embodiments of sampling bags, and only a few are shown. It can be seen that manufacturing, assembly and design with slightly different properties are easily adjusted to the sampling requirements. Any of the embodiments of sampling bags having flexible walls (including both metal alloy sheets and/or plastic laminates) may additionally include panels 23 capable of assisting in the use of the sampling bag. As shown in fig. 3, the panel may include a handle, and the handle 25 may be collapsible, partially pre-cut from the same material as the panel shown in fig. 3-a, and engaged by hand or other mechanism as shown in fig. 3-b, 4-a, and 4-b. Materials such as, but not limited to, cardboard, corrugated paper, or plastic sheets are suitable for the side panels. Fig. 4 shows the process of inflating and filling the sampling bag by simply pulling the two side panels of the bag outward. This sampling is extremely advantageous compared to any other pump method, which is especially directed to grab sampling. The bag may be filled and purged several times in succession to allow dynamic equilibration of the sampled fluid mixture on the bag walls. This procedure cannot be easily performed by any existing sampling bag or sampling method. The pollution and losses brought about by the pipes and pumps are significantly reduced. The recovery rate can be close to 100% compared to 85-90% for conventional pump-bag combination systems. The time for which the sample concentration is stable is about several times longer compared to the sample stored in the plastic bag. Fig. 5-a shows a bag wherein the side panels 23 overlap the walls of the bag after filling. Fig. 5-b shows a bag in which the side panels 23 are smaller than the size of the walls of the bag, the bag having foldable handles 26 attached to the side panels 23, the handles 26 being made of strips of other soft materials (fabric, mesh, plastic strips, etc.).

Fig. 6 shows another embodiment of a sampling bag comprising a flexible wall. The side panels 23 are made of a hard rigid material. In the embodiment shown in fig. 6, materials such as hard acrylic, polypropylene, ABC, or polycarbonate sheets are suitable for the sidewalls. The side panels 23 may be biased away from each other by a spring 28 positioned between the panels 23. The expansion of the sampling bag from the flat empty position creates an under pressure within the sampling bag 22 that creates a driving force for the fluid to enter the bag. The spring may be selected from the group including: a leaf spring (as shown), a wave spring 28, a butt-to-butt spring, or a coil or coil spring. The most preferred for several embodiments may be the selected leaf spring and counter spring because of its small initial height compared to the height of the expansion spring, which allows the side panels 23 to be positioned very close together when the bag 22 is empty with a panel of simple design. An advantage of the design shown in fig. 6 is that the sampling bag can be used to perform a self-sampling process. Self-sampling provides the convenience of long-term sampling without a pump. To perform long term self-sampling, a consistent low flow should be achieved during the sampling period.

Embodiments of the sampling bag may further comprise a multi-function inlet valve. The valve may include different features, including an inlet with a simple shut-off valve and an inlet with a restricted flow rate. Simple shut-off valves have on/off capability and are used primarily for grab-method sampling. Grab sampling can be commonly used to obtain "instantaneous" samples of industrial sanitary environment samples. The samples were then analyzed in the laboratory to determine the concentration of the various components present at the time of sampling. An inlet with a restricted flow rate may be used to obtain a sample during a sampling period. The sample can then be analyzed in the laboratory to determine the average concentration of the various components over the sampling period. The sampling period may be any desired period of time, such as, but not limited to, fifteen minutes, thirty minutes, one hour, four hours, or eight hours.

In general, embodiments of the sampling valve may be used with a novel sampling method that samples according to a quick grab method and/or samples over an extended period of time. Conventional sampling valves are unable to perform all of these functions. Conventional valves are simple shut-off valves that are mainly convenient for grab-method sampling. Completely new sampling inlet/outlet flow regulating devices must be designed to fulfill all necessary requirements.

FIGS. 7, 8-A, 8-B, and 9 show an embodiment of a sampling valve or sampling head 50. The sampling head 50 has several different features and functions.

The embodiment shown in fig. 7 and 8 includes an on/off control valve and can be opened (on) and closed (off) by pivoting the valve stem 35, wherein the valve is open when the longitudinal axis of the valve stem is oriented parallel to the longitudinal axis of the base and closed when the longitudinal axis of the valve stem is oriented perpendicular to the longitudinal axis of the base. Of course, the operation may be reversed, with the valve open when the longitudinal axis of the valve stem is oriented perpendicular to the longitudinal axis of the base, and the valve closed when the longitudinal axis of the valve stem is oriented parallel to the longitudinal axis of the base. The sampling valve or sampling head may be used for grab sampling or to connect to other sampling devices such as pipes and pumps through connections to the valve stem or intermediate parts such as the pipe connector 52, the barb pipe connector 53 or other connector or inlet devices. Typically, the connectors and other parts may be sealed with gaskets 33.

Embodiments of the sampling valve or sampling head 50 may include an inlet 36 having a calibrated pneumatic resistance. The inlet 36 with calibrated pneumatic resistance is designed to have a consistent flow rate over a period of time. The inlet 36 with calibrated pneumatic resistance is designed to maintain the flow rate within a specified flow range for a desired time, even with some pressure fluctuations. The inlet 36 with calibrated pneumatic resistance can be used to take samples for extended sampling periods. Embodiments of the sampling valve or sampling head may have more than one inlet 36 with a calibrated pneumatic resistance. The inlet can be calibrated for different sampling periods to easily accommodate different sampling procedures and operations with the same sampling bag.

Embodiments of the sampling valve or sampling head may include a quick connection on the valve stem 35. The quick connection may be used to add various accessories to the sampling valve or sampling head 50. Such accessories may include (but are not limited to): a clamp with a septum 40 for syringe/needle transfer or fluid sampling; a pipe connector 52 for fluid transfer; barb-type tubing connectors 53 for fluid transfer; an inlet 39 with an aerodynamic drag designed for a particular sampling period and/or flow rate. The sampling period and/or flow rate may be adjusted by changing the length and/or diameter of the flow path, e.g., inlet 39.

The use of the sampling head 50 may involve several steps depending on the type of sampling-grab sampling or extended cycle sampling. For grab sampling, the sampling bag can be flattened by pushing the wall, for example by hand, by machine, or with a weight. The sampling valve or sampling head of the bag can be opened to empty the sample, for example as shown in fig. 7. The sampling bag may also be connected to a vacuum source to evacuate the bag. This may be performed by attaching a semi-hard pipe 52 or a barbed pipe connector 53 (see fig. 8-a, 8-B) to the quick connect socket 42. The vacuum pump may be a syringe, a pocket pump, or other vacuum source (not shown in the figures). Subsequently, the sampling head 50 is pivoted along a 90 ° angle to the vertical position shown in fig. 8A (no septum assembly 42 is introduced). When the sampling head 50 is again folded to the parallel position as in fig. 7, the septum assembly 42 can be removed and sampling performed simply by a rapid inflow. The procedure can be repeated several times to ensure wall saturation of the target composition and better sample recovery. After the bag 22 of the assembly 10 is shown containing a sample, the sampling head can be pivoted through a 90 ° angle again, and the sampling diaphragm assembly 42 can be connected to the valve stem 35. The bag assembly is ready for shipping and/or sampling. In addition, a sample for laboratory analysis may be taken via diaphragm 40 when ball valve 34 is reopened as in FIG. 7. Alternatively, the sample may be obtained by replacing assembly 42 with a semi-rigid connector tube 52 for fluid transfer as shown in FIG. 8-A. In many embodiments, all operations may be performed in one minute. The ball valve open/close function can be performed with only one hand, if desired, immediately after sampling is complete. One-handed operation of the valve is advantageous for grab sampling when performing as shown in fig. 4 using two hands to open the bag assembly.

For long term sampling, the bag 10 is in the starting position shown in fig. 7, with the hexagonal socket 37 set in place when the orifice 44 on the valve stem socket 35 is aligned with the pneumatic resistance 36 (shown as a microcapillary tube in fig. 7 and 8). The socket on the valve stem 35 mates with the diaphragm assembly 42 and flow is possible only through the pneumatic resistance 36. The resistance 36 is calibrated for long-term sampling of one of the normalized sampling times: 15 minutes, 30 minutes, and 1 hour, 2 hours, 4 hours, 8 hours, 24 hours (or other desired time). After the sampling time expires, the turret is rotated to an angle at which the pneumatic resistance is not fluidly connected to the orifice 44, the sampling head 50 is bent at a 90 ° angle, and the bag assembly 10 is ready for shipment or immediate analysis. Further, the septum assembly 42 is used for syringe/needle sample retrieval, or the septum may be replaced as needed by a semi-rigid tube connector for fluid transfer. The combination 42 may also be replaced by any pneumatic resistance in the socket 39, tailored and calibrated thereto, as shown in fig. 9.

Feature(s)

The present invention proposes an embodiment of a novel type of sampling or self-sampling bag with a sampling inlet (sampling head) of the original type. Two novelty properties that bring along many new features are compared to all prior art sampling with bags or jars:

without any type of pump to expel fluid or fill fluid into the container

No need for battery charging and maintenance

No need for pump calibration

Easy change of sampling mode by means of a multifunctional sampling head-grab sampling/long-term sampling over a number of predetermined sampling times

Extremely simple operation-without special restrictions

Cheap sampling process-low use cost

One person may run several parallel sampling devices or a continuous sampling operation. Extreme efficiency of labor

Operating the primary mode set on the sampling head with only one hand

Low manufacturing costs

Higher recovery-close to 100% in the case of grab sampling

Substantially no adsorption on the wall of the external line or of the internal pump

Substantially free of cross-contamination

All directly sampled volumes are available

Is always ready for sampling

Many containers can fit in a relatively small volume when empty and the inlet is closed (portability is of paramount importance for field sampling)

When loaded, the device is portable and easy to post

The device is intrinsically safe and provides intrinsically safe sampling.

The described embodiments of the methods and flexible-walled sampling bags are not limited to the specific embodiments, method steps, and materials disclosed herein because such formulations, process steps, and materials may vary somewhat. Also, the terminology employed herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting, as the scope of the various embodiments of the present invention will be limited only by the appended claims and equivalents thereof.

Thus, while embodiments of the invention have been described with reference to exemplary embodiments, those skilled in the art will appreciate that variations and modifications may be effected within the scope of the invention as defined by the appended claims. Accordingly, the scope of various embodiments of the present invention should not be limited to the embodiments discussed above, but should be defined only by the appended claims and all equivalents thereof.

Claims (67)

1. A sampling bag, comprising:

at least one flexible wall, wherein the flexible wall comprises at least one layer comprising a metal alloy; and an inlet.

2. The sampling bag of claim 1, wherein the flexible wall comprises at least one layer comprising a sheet of metal alloy.

3. The sampling bag of claim 1, comprising two flexible walls comprising at least one layer of a metal alloy sheet.

4. The sampling bag of claim 3, wherein the two flexible walls are joined to form the sampling bag.

5. The sampling bag of claim 1, wherein the sheet has a thickness in a range from 25 to 50 microns.

6. The sampling bag of claim 1, wherein the layer consists essentially of a flat sheet of stainless steel.

7. The sampling bag of claim 1, wherein the layer consists essentially of corrugated sheets of stainless steel.

8. The sampling bag of claim 1, wherein the metal alloy is selected from the group comprising: stainless steel alloys such as SST 304, SST 309L, SST 316, SST 316L, SST 321 1, SST 321L, low carbon stainless steel, nitinol, nickel or titanium.

9. The sampling bag of claim 1, comprising at least one panel attached to the flexible wall.

10. The sampling bag of claim 3, comprising at least one panel attached to each of the flexible walls.

11. The sampling bag of claim 10, wherein the panels comprise a material selected from cardboard, corrugated paper, or corrugated board, and a handle.

12. The sampling bag of claim 10, comprising a spring capable of biasing the panel.

13. The sampling bag of claim 11, wherein the spring biases the panels away from each other or biases the panels toward each other.

14. The sampling bag of claim 1, comprising a valve on the inlet.

15. A sampling bag according to claim 14, wherein the valve comprises a quick disconnect connector or a plurality of inlets comprising shaped apertures resulting in different flow characteristics under the same flow conditions.

16. A method of forming a sampling bag, comprising:

sealing the peripheries of at least two sheets of corrosion-resistant metal alloy to form the sampling bag; and

an access opening is provided to access the space between the two sheets.

17. The method of claim 16, wherein the sheet is 25 or 50 microns thick.

18. The method of claim 16, wherein sealing the perimeters of the two sheets comprises welding the perimeters of the two sheets.

19. The method of claim 18, wherein welding the perimeters of the two sheets comprises laser welding the perimeters of the two sheets.

20. The method of claim 16, wherein sealing the perimeter comprises forming a seam from 0.5 to 1.5mm wide.

21. The method of claim 16, wherein providing an inlet comprises forming an aperture in at least one of the metal alloy sheets.

22. The method of claim 21, wherein forming an orifice comprises impinging an orifice.

23. The method of claim 21, wherein forming an aperture comprises cutting an aperture.

24. The method of claim 23, wherein cutting an aperture comprises laser cutting an aperture.

25. The method of claim 16, further comprising installing a valve in the orifice.

26. The method of claim 25, wherein the valve comprises a quick disconnect connector.

27. The method of claim 25, wherein the aperture is sealed by mounting the valve using a gasket.

28. The method of claim 16, wherein one of the sheets overlaps another sheet.

29. The method of claim 16, comprising passivating the space between the two sheets.

30. The method of claim 29, wherein the passivating the space between the two sheets comprises adding an acid to the sampling bag.

31. The method of claim 29, wherein passivating the space between the two sheets comprises filling the pocket with an acid.

32. The method of claim 30, wherein the acid is nitric acid or citric acid.

33. The method of claim 30, wherein the concentration of the acid is from 3% to 5%.

34. The method of claim 29, comprising drying the interior of the bag.

35. The method of claim 34, wherein drying the interior of the bag comprises heating the bag to a temperature above 60 ℃ under vacuum.

36. The method of claim 16, comprising chemically polishing at least one side of each of the two corrosion-resistant metal alloy sheets.

37. The method of claim 36, wherein chemically polishing comprises treating the wall with a reactant comprising a mixture of hydrochloric acid, nitric acid, and hydroxybenzoic acid in the presence of a cationic surfactant and a ferricyanide complex at a temperature range of 35 ℃ to 50 ℃ for 6 to 12 hours.

38. The method of claim 16, comprising chemically passivating at least one surface on each of the sheets prior to sealing the perimeter.

39. The method of claim 38, wherein chemically passivating comprises treating the surface with 3% citric acid at 50 ℃ for about 2 hours.

40. The method of claim 24, wherein the valve comprises at least one material selected from the group comprising PTFE, FEP, Delrin, acetal, or stainless steel.

41. The method of claim 39, wherein the stainless steel of the valve is the same material as the sheet.

42. The method of claim 16, comprising laminating an outer surface of the wall with a plastic material.

43. The method of claim 17, wherein the plastic material has charge dissipative properties.

44. The method of claim 41, wherein the plastic material has high thermal stability.

45. The method of claim 44, wherein the plastic material is thermally stable at 100 ℃.

46. The method of claim 42, wherein the plastic material is a vinyl material laminated with an acrylic adhesive or a fluorocarbon laminated with a silicon-based adhesive.

47. The method of claim 42, wherein the plastic material is laminated prior to sealing the perimeter.

48. The method of claim 47, wherein the plastic material extends beyond the sheet and is heat sealed.

49. The method of claim 48 including an interior sealing material on the inside of the plastic sheet around the perimeter.

50. The method of claim 49, wherein the interior sealing material is a fluorocarbon.

51. The method of claim 16, comprising folding the perimeter.

52. The method of claim 50, comprising folding the perimeter twice.

53. The method of claim 16, comprising attaching a panel to an outer surface of the wall.

54. The method of claim 53, wherein the panel comprises a handle.

55. The method of claim 54, wherein the panel comprises a semi-rigid flexible material.

56. The method of claim 54, wherein the panel comprises a material selected from the group consisting of paperboard, corrugated paper, or corrugated board.

57. A sampling valve for a sample container comprising

A base; and

a valve stem comprising a connector, wherein a valve is open when a longitudinal axis of the valve stem is oriented parallel to a longitudinal axis of the base, and the valve is closed when the longitudinal axis of the valve stem is oriented perpendicular to a longitudinal axis of the base.

58. The sampling valve according to claim 57, wherein the valve stem comprises a quick disconnect connector capable of receiving a plurality of sampling accessories.

59. The sampling valve of claim 58, wherein the sampling accessory includes a tubing connector, a septum holder, or an inlet comprising a calibrated pneumatic resistance.

60. The sampling valve of claim 59, wherein the inlet is calibrated to at least partially fill the sampling bag in a time selected from 15 minutes, 30 minutes, one hour, two hours, four hours, eight hours, or twenty-four hours.

61. A sampling valve comprising a multi-position valve, wherein the multi-position valve comprises at least two inlets and one three-position valve.

62. The sampling valve of claim 61, wherein each of the inlets is a calibrated aerodynamic drag flow path.

63. The sampling valve of claim 62, wherein each of the inlets is calibrated for different flow rates under the same conditions.

64. The sampling valve of claim 61, comprising three interchangeable inlets, wherein each of the inlets is calibrated for different flow rates under the same conditions.

65. The sampling valve of claim 61, comprising a turret for selectively opening the valve to one of the inlets or for closing the valve.

66. The sampling valve of claim 61, wherein the sampling valve comprises a second valve, wherein the second valve is an on/off valve having two positions, wherein one position opens the valve and a second position closes the valve.

67. The sampling valve of claim 66, wherein the second valve comprises a base and a stem, wherein the second valve opens when a longitudinal axis of the stem is oriented parallel to a longitudinal axis of the base and closes when the longitudinal axis of the stem is oriented perpendicular to a longitudinal axis of the base.