TWIN AIR CURTAIN SYSTEM AND METHOD FOR USING SAME

Abstract

An air curtain system for separating a gas or vapor from atmosphere is provided. The air curtain system includes a first channel, a second channel, a first blower, and a second blower. The second channel may be adjacent and parallel to the first channel and may include an inlet and an outlet. The first channel may be configured to form an essentially closed loop such that the first blower recirculates air through the first channel. The inlet of the second channel may be configured to allow the second blower to draw in atmospheric air. The first channel may have a first opening configured to open to a chamber or containment area. The first channel may have a second opening configured to open to the second channel. The second channel may have an opening configured to open to atmosphere.

Description

FIELD OF THE INVENTION

The present invention relates air curtains and vapor and gas containment barrier systems, particularly air curtains and containment barrier systems that restrict vapor loss and heat transfer without the need of a complete physical barrier.

BACKGROUND OF THE INVENTION

Air curtain technology is employed to create a barrier to reduce the loss of cold or hot air from a contained space or to protect from contamination. However, known air curtain technology still allows for meaningful amounts leakage or transfer across the barrier. Thus, in applications where restricting the amount of transfer is necessary, such known air curtain technology is unsatisfactory.

There are also several applications where it is desirable to create a containment system that can contain a quantity of air, vapor, or gas (including aerosol laden air) within an enclosed space for long durations of time at precise temperatures and concentrations without any solid or physical barrier. For example, some optical tests of chemical vapors and gases require testing without any physical obstruction whatsoever between the vapor and the testing device on order to accurately analyze the vapor or gas being tested. These tests can require the concentration of the gas to be precisely known and therefore systems that fail to adequately restrict fluid loss through the barrier are undesirable. Thus, it may be desirable to use an air curtain system to contain the vapor for such tests if not for the poor efficiency of known technologies in containing vapors.

Accordingly, a need exists for an improved air curtain system that can effectively contain vapors or gases without significant loss and without the use of a physical barrier or optical obstruction on at least a portion of the system.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed generally to a containment barrier system for containing a vapor or gas in a confined area without a complete physical barrier. The present invention is further directed to an air current or air curtain system to contain a vapor or gas without a complete physical barrier and/or separate the vapor or gas from the surrounding atmosphere. The air current or air curtain system may include both a single pass air curtain and a recirculating air curtain in connection with a gas or vapor containment barrier system. The air curtain system may be used with the containment barrier system to contain a gas or vapor within a chamber for laser, optical, or spectroscopy testing. The air curtain system can allow for the testing of the gas or vapor within the chamber without the obstruction of a physical barrier or barrier that may otherwise confound or distort optical signatures. The air curtain system may also be used in several different applications where containment of a gas or vapor within a confined space without a fully enclosed physical barrier is necessary. The system can effectively contain the gas or vapor in the chamber such that the gas or vapor concentration is effectively maintained and such that minimal escape or loss of gas or vapor to atmosphere is allowed.

According to one embodiment, an air curtain system includes a first air stream and a second air stream. The first air stream may be directed to flow in a first direction and the second air stream may be directed to flow in a second direction substantially parallel to the first direction. The first air stream may be configured to recirculate within an essentially closed loop system. The second air stream may be configured to pull in air from atmosphere.

In some embodiments of the air curtain system, the first air stream may be configured to flow in a first channel, and the second air stream may be configured to flow in a second channel. The first channel may include a first opening configured to open to a chamber or containment area and a second opening configured to open to the second channel. The second channel may include an opening configured to open to atmosphere. The first air stream may be propelled by a first blower, and the second air stream may be propelled by a second blower. The first air stream or the second air stream may include a screen for straightening airflow. An air speed of the first air stream may be configured to be between 0.85 to 1.15 times an air speed of the second air stream.

According to another embodiment, a system for testing a gas or vapor includes a chamber for the gas or vapor and an air curtain system disposed adjacent to an opening to the chamber. The air curtain system may include first and second channels adjacent and parallel to one another. The first channel may have a first opening corresponding to the opening of the chamber and a second opening corresponding to the second channel. The second channel may have an opening to atmosphere external to the system. The system may further include a second air curtain system located proximate to a second opening in the chamber. The system may further include a detecting apparatus located external to the chamber and configured to test properties of the gas or vapor within the chamber. The detecting apparatus may be an FTIR.

Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the accompanying drawing figures.

DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith in which like reference numerals are used to indicate like or similar parts in the various views:

FIG. 1 is a schematic view of an optical test system and chamber in accordance with an embodiment of the present invention;

FIG. 2 is a schematic view of a single pass air curtain system in accordance with an embodiment of the present invention;

FIG. 3 is a schematic view of a recirculating air curtain system in accordance with an embodiment of the present invention;

FIG. 4 is a schematic view of a combination air curtain system in accordance with an embodiment of the present invention;

FIG. 5 is a partial sectional perspective view of the combination air curtain system of FIG. 4;

FIG. 6 is a schematic view of a testing apparatus incorporating the combination air curtain system of FIG. 4;

FIG. 7 is a partial perspective view of the testing apparatus of FIG. 6;

FIG. 8 is a partial perspective view of a housing of the testing apparatus of FIG. 6, as shown in accordance with an embodiment of the present invention; and

FIG. 9 is a schematic view of a containment barrier system with air curtain systems in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures. It will be appreciated that any dimensions included in the drawing figures are simply provided as examples and dimensions other than those provided therein are also within the scope of the invention.

The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled.

The present invention is directed generally to containment barrier systems and for containing a vapor or gas in a confined area without a complete physical barrier. The present invention is also directed generally to an air current or air curtain system 10 for separating a vapor or gas from atmosphere of the surrounding environment. Air curtain system 10 may include both a single pass air curtain 12 and a recirculating air curtain 14 as illustrated in the figures. Air curtain system 10 as described herein may be used in connection with a gas or vapor containment barrier system. One exemplary embodiment of a containment barrier system may include the use of air curtain system 10 to contain a gas or vapor within a chamber 16 for laser, optical, or spectroscopy testing, such as Fourier-transform infrared (FTIR) testing. Air curtain system 10 allows for the testing of the gas or vapor within the chamber 16 without the obstruction of a physical barrier or barrier that may otherwise confound or distort optical signatures. Air curtain system 10 may also be used in several different applications where containment of a gas or vapor within a confined space without a fully enclosed physical barrier is necessary.

Turning to the figures, FIG. 1 shows a chamber 16 containing a gas or vapor cloud. The chamber 16 may include chamber openings 18 on either end to allow for optical or spectroscopy testing, such as by using FTIR 20 to transmit and detect light into and out of the chamber 16. The FTIR 20 may be aligned with the chamber openings 18 such that only the environmental air and the gas or vapor in the chamber 16 absorb and refract/reflect the signals to and from the FTIR 20. Using plexiglass, plastic, glass, zinc selenide (ZnSe), or other transparent covers to seal the chamber openings 18 can contain the gas in the chamber 16. However, such plexiglass or other physical objects, regardless of how transparent they may be, will have some impact on the readings of the FTIR 20 or other testing devices, which can be extremely sensitive. Thus, it is desirable to not use a physical barrier to seal the chamber openings 18.

However, if the chamber openings 18 are not sealed, the gas can escape the chamber 16, which can make consistent testing of the gas difficult as the concentration within the chamber 16 constantly changes. Gas escaping the chamber can also be hazardous to users and the environment surrounding the chamber 16. Thus, air curtain system 10 may be used to help seal the chamber 16 and prevent escape of the contained gas while not obstructing the FTIR 20 or otherwise providing optical interference.

As shown in FIG. 2, a single pass air curtain 12 may be used to seal the chamber opening 18 by passing or running a stream of air directly against and along the chamber opening 18. The air stream may be at least partially contained in a channel 22 to help direct the air stream flow. The channel 22 may include a first channel opening 24 that corresponds to the chamber opening 18 and a second channel opening 26 opposite the first channel opening 24 that together allow for an unobstructed optical line of sight into the chamber 16. The air stream and the gas in the chamber 16 may form an air stream-gas boundary 28 where the first channel opening 24 meets the chamber opening 18 (i.e., the air stream-gas boundary 28 may be a window opening between the channel 22 and the chamber 16). Similarly, the air stream and the environmental or atmospheric air outside of the channel 22 may form an air stream-atmosphere boundary 30 at the second channel opening 26 that may be exposed to the atmosphere.

The single pass air curtain 12 may continuously pull or use clean or atmospheric air to help contain the gas in the chamber 16. Due to the velocity of the air stream and the fluid dynamic interaction between the air stream and the gas at the air stream-gas boundary 28, some of the gas may be prevented from escaping the chamber opening 18. However, some of the gas or vapor can enter or be pulled into the air stream at the air stream-gas boundary 28 (and some of the clean or atmospheric air may enter the chamber 16) as illustrated in FIG. 2. The channel 22 may have a sufficient width such that any gas in the chamber 16 that escapes through the air stream-gas boundary 28 is carried away by the air stream along the air stream path before the gas can reach the air stream-atmosphere boundary 30. For example, the channel 22 may have a width W between the air stream-gas boundary 28 and the air stream-atmosphere boundary 30 that is at least 0.25 times, and in some embodiments approximately 0.5 times, a height H of the air stream-gas boundary 28 that is parallel to the direction of the air stream (e.g., the height of the window opening as shown in FIG. 7). Further, the air stream-gas boundary 28 may have a depth D (e.g., the width of the window opening as shown in FIG. 7) that is perpendicular to the direction of the air stream that is approximately 3-4 times the width W between boundaries 28, 30 (this relation may alternatively be described as the width W relative to the depth D, where W/D may be approximately 0.25-0.30). The depth D may also be configured as approximately 0.5 times the height H. For example, in one embodiment, the depth D may be approximately 11 inches, the width W approximately 3 inches, and the height H approximately 5⅞ inches. For example, in another embodiment, the depth D may be approximately 16.5 inches, the width W approximately 5 inches, and the height H approximately 9.5 inches.

Instead of being allowed to freely enter the atmosphere through the air stream-atmosphere boundary 30, any gas that enters or is entrained in the air stream may be carried on by the air stream to another location such as a filter or an exhaust. In this way, the single pass air curtain 12 may generally prevent gas from freely escaping into the atmosphere. However, the single pass air curtain 12 may experience high loss at air stream-gas boundary 28 as gas enters the air stream and air from the air stream enters the chamber 16. This can result in significant reduction of the concentration of the gas in the chamber 16, which can present testing and efficiency issues. Further, if the gas or the other contents of the chamber 16 have a set temperature that differs from the atmospheric air used in the single pass air curtain 12, that temperature may be disturbed by mixing of the gas and air.

As shown in FIG. 3, a recycled or recirculating air curtain 14 may be configured similar to the single pass air curtain 12. The recirculating air curtain 14 may use a closed-loop system such that the air is recirculated from the outlet of the air curtain 14 back to its inlet. This recycling of air can reduce the amount of loss at the air stream-gas boundary 28 because the air stream may eventually reach a state where it has a similar concentration of gas as in the chamber 16. However, because the air stream is recycled and “contaminated” by the gas, the gas can more readily escape into the atmosphere via the air stream-atmosphere boundary 30 on its recirculated pass through. Thus, a recirculating air curtain 14 may be undesirable in certain situations, such as when the gas is hazardous. Accordingly, a system is desired that has low loss at both the air stream-gas boundary 28 and the air stream-atmosphere boundary 30, and more advantageously, a system that as a whole has no loss or essentially no loss at the boundary (i.e., can serve as a primary mode of containment).

As shown in FIGS. 4 and 5, air curtain system 10 may include both a single pass air curtain 12 and a recirculating air curtain 14 operating as a collective system. The recirculating air curtain 14 may be used immediately adjacent the chamber 16 to significantly reduce loss at the air stream-gas boundary 28. The single pass air curtain 12 may be used adjacent the recirculating air curtain 14 such that the air streams of each air curtain 12, 14 are parallel. The air curtain system 10 may include a third channel opening 32 between the single pass air stream channel 22a and the recirculating air stream channel 22b wherein an intermediate boundary 34 is formed between the two parallel air streams.

This configuration can provide for low loss at the air stream-gas boundary 28 and little to no gas escaping into the environment via the air stream-atmosphere boundary 30. The air streams of the air curtains 12, 14 may also be directed to flow in the same direction, which can result in extremely little mixing and low losses at the intermediate boundary 34. Thus, the overall loss of the air curtain system 10 may be even lower than a recirculating air curtain 14 alone as the recirculating air curtain 14 portion of the system 10 may be allowed to reach an essentially stable state wherein the recirculating air has the same gas concentration as in the chamber 16. Moreover, temperature disturbances in the chamber 16 may be substantially reduced or eliminated due to the prevention or reduction of atmospheric air crossing the intermediate boundary 34 and subsequently crossing the air stream-gas boundary 28 to enter the chamber 16.

As shown in FIG. 5, each of the air streams may be propelled or directed by a fan or blower 36, which may have a centrifugal impeller. In the embodiment shown, the blower 36a of single pass air curtain 12 and the blower 36b of the recirculating air curtain 14 may be configured to rotate on a common axis. In some embodiments, the blowers 36 may share a common drive shaft and be driven to rotate together. In these embodiments, the speeds of the blowers can be matched and only a single blower motor is necessary. In some embodiments, the blowers 36a, 36b may each be independently driven and may optionally be located at non-adjacent locations within the system 10.

Even when using a single motor and drive shaft, the speed of the single pass air curtain 12 may be varied in comparison to the speed of the recirculating air curtain 14 using gear systems or the like. In some embodiments, it may be desirable to configure the speed of the blowers 36 and the size of the channels 22a, 22b such that the velocity of the air stream in the single pass air curtain 12 is approximately 5-15% higher than the velocity of the air stream in the recirculating air curtain 14. For example, the air velocity of the recirculating air curtain 14 may be approximately 1.0-1.2 meters/second (m/s), and the air velocity of the single pass air curtain 12 may be approximately 1.1-1.4 m/s (as measured at the center of the air stream in the channel 22). The specific blower speeds, channel sizes and resulting airflow velocities may be specifically selected and configured to minimize mixing at boundaries 28, 30, or 34, and particularly optimized to minimize mixing at the intermediate boundary 34.

The channels 22 may be sized and the air velocity configured such that the air streams are substantially laminar and there is little to no turbulence at or near any of the boundaries 28, 30, 34 (i.e., mixing at the boundaries is reduced). It may be advantageous to configure air curtains 12 and 14 with low air velocities in order to minimize the amount of material transfer between boundary 34 and material loss from recirculating air curtain 14. However, once the air velocities drop below a threshold value, then the system 10 may be susceptible to environmental perturbations and disturbances that affect efficiency. The exemplary air velocities described above have been shown to be optimal for laminar flow and material retention at the boundary in certain applications.

The channels 22 may include a sufficient length of straight ductwork upstream of the boundaries 28, 30, 34 such that any turbulence in the airflow (e.g., from the blower 36 or bends in ductwork or other directional changes imparted on the airflow) can substantially dissipate before the boundaries 28, 30, 34. In addition to including a sufficient length of duct or in lieu of it when under space constraints, a screen 35 may be included in the channel 22 to help direct and “straighten” airflow as it is discharged from the blower 36 to provide more uniform or laminar-like flow near the boundaries 28, 30, 34. Often as air exits the blower 36, it is substantially non-uniform in direction in a manner that can cause turbulent flow downstream. Screen 35 may operate to remove or “break up” large turbulent eddies and may orient and provide a resistance to the airflow to provide a more uniform airflow prior to the airflow entering the view or look-path of the FTIR 20. In addition, screen 35 may be sized based on the airflow velocity in each curtain 12, 14 in order to create an optimal uniform airflow.

As shown in FIG. 5, an inlet 38 of the single pass air curtain 12 may receive clean atmospheric air (clean airflow shown in dashed arrows for FIG. 5 only), and an outlet 40 may direct the air stream, which may be partially “contaminated” or include some of the gas from the chamber 16 (contaminated airflow explicitly shown in solid arrows for FIG. 5 only), to a filter and/or exhaust. The channel 22b of the recirculating air curtain 14 may be a closed loop system such that the blower 36b receives and recirculates substantially the same contaminated airflow that continuously passes through the channel 22b (i.e., recirculates the air from downstream of the boundaries 28, 34). In addition to controlling the flow rate in each air curtain 12, 14 by modulating the speed of the blowers 36, the exhaust of single pass air curtain 12 may include an adjustable valve (not shown) that can be adjusted to change the pressure and flow within the air curtain 12. This valve can be used to further control and match the air flow between both curtains 12 and 14. Similarly, recirculating air curtain 14 may include an integrated valve to help regulate the air pressure and flow rate.

Optical detection of chemical vapors or gases is important for a variety of applications. For example, technologies that can investigate the composition of a vapor cloud from a distance is an important component of warfighter protection and against biological attacks. However, such technologies (such as FTIR 20) must be tested and calibrated against known concentrations of known vapors, gases, or aerosol chemicals in a variety of real-world environments and backgrounds. Testing or calibrating such technologies on vapor clouds contained within a completely physically sealed barrier, even if transparent, can result in interferent signals due to the non-optically pure look-path, which results in inaccurate test results for the degree of optical precision required. Testing vapor clouds in other known vapor cloud containment systems has resulted in quick dispersion of the vapor cloud (poor containment resulting in rapid changes in concentration) such that accurate testing cannot be obtained.

Accordingly, a need exists for a vapor cloud containment system that allows such technologies to be tested and calibrated with a known, stable concentration of vapors and a stable temperature without any physical barrier between the technologies and the vapor cloud. Further, it may be desirous to be able to test or calibrate with a variety of “optical backgrounds” that are similar to where the technology will be deployed.

As shown in FIG. 6, an air curtain system or systems 10 may be included in a gas or vapor detection system or test system 42. A chamber 16 containing the gas or chemical vapor to be tested may include an air curtain system 10 on each end of the chamber 16 to act as a seal or barrier for the chamber openings 18. The gas or vapor may be introduced and disseminated throughout the chamber 16 by any suitable means, including without limitation, via separate tubing or connections between the chamber 16 and a gas or vapor reservoir (not shown) or by release of a cartridge or other vapor containing or generating component within the chamber 16. According to one non-limiting example, a dissemination system may be plumbed into the chamber 16 such that concentrated jets of air enters slightly circumferentially (i.e., slightly parallel to the outer surface) of a round chamber 16 such that the jets of air induce a swirling motion that enhances mixing and dissemination of the gas or vapor throughout the chamber 16.

An optical test device or FTIR 20 may be directed through the unobstructed openings 18, 24, 26, and 32 of the chamber 16 and air curtain systems 10 (see FIG. 5) to detect signatures of the gas or chemical vapor without interference.

As shown in FIGS. 6-8, the test system 42 may be housed within a room or an enclosed testing environment or larger container 44. As best shown in FIG. 6, the testing system 42 may include an intake 46 for allowing fresh atmospheric air into the container 44 to be used by the single pass air curtains 12. As shown in the illustrated embodiment, supply tubing or ductwork 48 may connect the intake 46 to the air curtains 12 both on the “upstream” portion of the testing system 42 that is nearest the FTIR 20 and the “downstream” portion that is on the side of the chamber 16 opposite the FTIR 20. The intake 46 and supply ductwork 48 may also include a supply blower or fan 50 that can assist in supplying air to the blowers 36a via their corresponding inlets 38 (FIG. 5). Similarly, the outlets 40 of both the upstream and downstream air curtains 12 (see FIG. 5) may be connected to exhaust tubing or ductwork 52 that may direct the “contaminated” air from the outlets 40 of the air curtains 12 to an exhaust opening 54. The exhaust ductwork 52 may include or be routed to a filter 56, such as a carbon filter, MERV filter, or HEPA filter, which can help filter any gas or other contaminants from the exhaust air before it is exhausted to the atmosphere outside the container 44. The exhaust ductwork 52 or exhaust opening 54 may include an exhaust blower or fan 58 that can assist in pulling the air away from the air curtains 12 and out of the container 44 (as may be necessary to overcome the pressure loss associated with the filter 56).

As shown in FIG. 6, the supply ductwork 48 may include a tee or diverter 60 near the air curtain systems 10 that directs some of the supply airflow over the housing of the recirculating air curtain 14. This can provide convection cooling to the air curtain 14, which can in some cases otherwise overheat due to the heat generated by the blower 36b in its closed system. An active cooling system 62, such as a refrigeration system, may be included in the supply ductwork 48 to provide further or more controlled cooling of the air and the air curtain 14, even in instances when the atmospheric air is warm. Temperature gauges may be incorporated in the channels 22b and/or the chamber 16. The cooling system 62 may be modulated to keep the temperature change in the chamber 16 less than 10° C., in some instances, less than 5° C., and in some instances, less than 1° C.

As best shown in FIG. 6, the supply ductwork 48 may further include portions that are directed to a supply hood 64 located proximate the air stream-atmosphere boundary 30 of the air curtain system 10. The exhaust ductwork 52 may similarly include an exhaust hood 66 located proximate the air stream-atmosphere boundary 30 of the air curtain system 10 and directed to receive airflow from the supply hood 64. Such supply and exhaust hoods 64, 66 may be included adjacent both the upstream and downstream air curtains 10. Utilizing the supply and exhaust hoods 64, 66 can help remove any minute amounts of gas or contaminants from the container 44 that may have otherwise escaped the barrier provided by the air curtain systems 10, which can make the container 44 safer for occupancy during testing.

The supply ductwork 48 may further direct airflow at and over the FTIR 20 and other testing equipment and into a corresponding exhaust hood 66 on the upstream side, which can provide heat capture and convection cooling to the FTIR 20 and other testing equipment. On the downstream side, a third single pass air curtain 68 may be included in the testing system 42 just upstream of a light opening or test opening 70 included in the container 44. The test opening 70 can allow for the unobstructed line of sight of the FTIR 20 to be extended. The third air curtain 68 may be a high-speed air curtain and may provide an additional barrier to contaminants escaping the container 44.

In some embodiments, the test system 42 may retain an above-ambient concentration within the chamber 16 for long duration. After an initial dissemination and mixing period where air in the chamber 16 and air stream in the recirculating air curtain 14 reaches a target concentration (which typically takes less than ten minutes), the concentration in the chamber 16 can maintain homogeneous levels above ambient for extended periods of time (e.g., maintain a 4% to 6% decay rate of concentration present after the initial mixing for a time period of 30 minutes or more).

As shown in FIGS. 6-8, the test system 42 may be included in a container 44 that may be configured for transportation. For example, the container 44 may be a shipping container. As shown in FIG. 8, the container 44 may easily be transported on a trailer or the like. This allows container 44 and test system 42 to be conveniently transported, and any testing and calibrating may be done on-site. Thus, the environmental conditions (e.g., atmospheric air conditions, weather conditions, visibility), environmental backgrounds (e.g., desert, marine, mountain), and background interferents (e.g., smoke, fog) for testing can be selected to match the environmental conditions seen in the field by transporting the test system 42 on-site to the location of use.

Referring to FIGS. 4-8, air curtain 10 and detection system or test system 42 may be used in a method for testing a vapor or gas for identifying specific properties of the vapor or gas, determining the characteristics of the vapor or gas, and/or detecting the presence of specific chemicals or substances present in the vapor or gas. The method can include providing the detection system 42 with air curtain 10 as described herein. Next, a quantity of a specific gas or vapor may be disseminated within the chamber 16 of the system 42. The method may then further include the steps of operating the system 42, including air curtain 10 thereof, to mix the vapor or gas and achieve a target concentration within chamber 16, and then directing a spectroscopy or light emitting and detecting apparatus 20 (e.g., an FTIR) through the openings 18, 24, 26, and 32 of the chamber 16 and air curtain 10 to detect signatures and/or properties of the gas or vapor within the chamber 16. Each of the steps and components of the method for testing the gas or vapor may be configured and operate in accordance with the several configurations, aspects and features of air curtain 10 and detection or test system 42 described herein.

FIG. 9 illustrates a containment system 72 that includes air curtain system 10 for containing a gas or vapor concentration within a containment chamber 16. As shown, an air curtain system 10 may be provided on each end of the containment chamber 16 in order to provide containment chamber 16 with reduced physical barriers while still maintaining a gas or vapor within the interior of the chamber 16. Such system 72 may be utilized in several different applications, including as a testing chamber as described above with respect to test system 42. Containment system 72 may also be used in certain animal testing applications. For example, containment system 72 may be used when gases, chemicals or other agents are tested on animals, such as mice or rodents. Minimizing physical barriers may increase the reliability of the testing by minimizing a distressed state of the animal. Often, when physical barrier containment systems are used, the barrier creates a distressed stated in the animal, which can impact how the agent being tested affects the animal, particularly for respiratory interactions. However, removing the barriers prevents that gas concentrations necessary for accurate testing. Containment system 72 may be used in such instances while still allowing for controlled concentration of the gas within the chamber 16. The foregoing embodiments are just exemplary of the possible applications and configurations of containment system 72 and air curtain system 10 and not intended to be limiting. Containment system 72 and air curtain system 10 may also be used in several different applications where it is necessary to contain a gas or vapor within a confined space without a complete physical barrier.

Various embodiments of systems, devices, and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the invention. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations, locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the invention.

Persons of ordinary skill in the relevant arts will recognize that the subject matter hereof may comprise fewer features than illustrated in any of the individual embodiments described above. The embodiments described herein are not meant to be an exhaustive presentation of how the various features of the subject matter herein may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the various embodiments can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. Moreover, elements described with respect to one embodiment can be implemented in other embodiments even when not described in such embodiments unless otherwise noted.

The numerical ranges in this disclosure are approximate, and thus may include values outside of the range unless otherwise indicated. Numerical ranges include all values from and including the lower and the upper values, in increments of one unit, provided that there is a separation of at least two units between any lower value and any higher value. These are only examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value enumerated, are to be considered to be expressly stated in this disclosure.

As used herein, “a,” “an,” or “the” can mean one or more than one. For example, “an” image can mean a single image or a plurality of images.

The term “and/or” as used in a phrase such as “A and/or B” herein can include both A and B; A or B; A (alone); and B (alone). Likewise, the term “and/or” as used in a phrase such as “A, B, and/or C” can include at least the following embodiments: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone).

As used herein, the term “about” when referring to a measurable value such as an amount, a temporal duration, and the like, can include variations of +/−20%, more preferably +/−10%, even more preferably +/−5% from the specified value, as such variations are appropriate to reproduce the disclosed methods and systems.

From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are inherent to the structure and method. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting.

The constructions described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.

Claims

1. An air curtain system for separating a gas or vapor from atmosphere, the air curtain system comprising: a first channel;a second channel adjacent and parallel to the first channel, the second channel including an inlet and an outlet;a first blower configured to direct airflow through the first channel; anda second blower configured to direct airflow through the second channel;wherein the first channel is configured to form an essentially closed loop such that the first blower recirculates air through the first channel;wherein the inlet of the second channel is configured to allow the second blower to draw in atmospheric air;wherein the first channel has a first opening configured to open to a chamber or containment area, wherein the first channel has a second opening configured to open to the second channel, and wherein the second channel has an opening configured to open to atmosphere.

2. The air curtain system of claim 1, wherein a screen for reducing turbulence or for providing a resistance that enables a uniform flow is included in the first channel or the second channel.

3. The air curtain system of claim 1, wherein the outlet of the second channel is configured to direct airflow to atmosphere.

4. The air curtain system of claim 1, wherein the first blower includes a centrifugal impeller.

5. An air curtain system comprising: a first air stream; anda second air stream;wherein the first air stream is directed to flow in a first direction, wherein the second air stream is directed to flow in a second direction, and wherein the first direction and the second direction are substantially parallel;wherein the first air stream is configured to recirculate within an essentially closed loop system; andwherein the second air stream is configured to pull in air from atmosphere.

6. The air curtain system of claim 5, wherein the first air stream is configured to flow in a first channel, and wherein the second air stream is configured to flow in a second channel.

7. The air curtain system of claim 6, wherein the first channel has a first opening configured to open to a chamber or containment area, wherein the first channel has a second opening configured to open to the second channel, and wherein the second channel has an opening configured to open to atmosphere.

8. The air curtain system of claim 7, wherein the first air stream is propelled by a first blower, and wherein the second air stream is propelled by a second blower.

9. The air curtain system of claim 8, wherein a screen for straightening airflow is included in the first air stream or the second air stream.

10. The air curtain system of claim 9, wherein an air speed of the first air stream is configured to be between 0.85 to 1.15 times an air speed of the second air stream.

11. A system for testing a gas or vapor, the system comprising: a chamber configured to at least partially contain the gas or vapor, the chamber including an opening; andan air curtain system comprising: a first channel;a second channel adjacent and parallel to the first channel, the second channel including an inlet and an outlet;a first blower configured to direct airflow through the first channel; anda second blower configured to direct airflow through the second channel;wherein the first channel is configured to form an essentially closed loop such that the first blower recirculates air through the first channel;wherein the first channel has a first opening adjacent to the opening of the chamber, wherein the first channel has a second opening adjacent to the second channel, and wherein the second channel has an opening configured to open to atmosphere.

12. The system of claim 11, further comprising a second air curtain system; wherein the chamber includes a second opening, and wherein the second air curtain system has an opening adjacent to the second opening of the chamber.

13. The system of claim 11, further comprising an exhaust duct configured to carry away contaminated air from the outlet of the second channel.

14. The system of claim 13, wherein the exhaust duct includes a filter, and wherein the filter is a carbon filter, a MERV filter, or a HEPA filter.

15. The system of claim 11, further comprising a spectroscopy or light emitting and detecting apparatus, wherein the detecting apparatus is located external to the chamber and directed to test properties of gas or vapor contained in the chamber.

16. The system of claim 15, wherein the detecting apparatus is an FTIR.

17. The system of claim 11, further comprising a supply duct configured to supply atmospheric air to the inlet of the second channel.

18. The system of claim 17, wherein the supply duct is further configured to direct air at the first blower or the first channel for cooling.

19. The system of claim 18, wherein the supply duct includes an active cooling system to cool the atmospheric air.

20. The system of claim 11, wherein the air curtain system is a first air curtain system, wherein the system includes a second air curtain system, wherein the opening in the chamber is a first opening, wherein the chamber includes a second opening, wherein the first air curtain system is configured to prevent vapor from escaping the first opening of the chamber, wherein the second air curtain system is configured to prevent vapor from escaping the second opening of the chamber, and wherein there is a line-of-sight through the first air curtain system, the chamber, and the second air curtain system that is unobstructed by any physical barriers.