GB2527559A - Apparatus for sampling chemical substances, and methods therefor - Google Patents

Abstract

An apparatus for sampling and processing at least one hazardous substance within a target volume (109, fig 1) comprises: (a) a container 102 having the target volume disposed therein; (b) an adsorption arrangement, including at least one sorbent (406, fig 4) having an adsorption surface adapted to adsorb gas-phase molecules disposed within a sorbent housing (400, fig 2); and (c) a fluid transfer arrangement 110, adapted and disposed to: (i) withdraw gas from within said container during a gas withdrawal mode; and (ii) deliver the gas to the adsorption surface, during a sampling mode. The adsorption surface has a characteristic pore diameter of at least 65 micrometers (µ). The apparatus may also comprise a recirculation loop (200, fig 2) attached to the container, a recirculation pump (210, fig 2) and a heating arrangement (116, fig 2) adapted to heat gas as it transits the recirculation loop. The loaded sorbent may be delivered to a biosensor, such as a sniffer dog.

Description

Intellectual Property Office Application No. GB1411328.6 RTTVI Date:t6 December 20t4 The following terms are registered trade marks and should be read as such wherever they occur in this document: Tenax Sigma-Aldrich Intellectual Property Office is an operating name of the Patent Office www.ipo.govuk Annaratus for Samnhin2 Chemical Substances. and Methods Therefor

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to apparatus for sampling chemical substances, and methods therefor.

SUMMARY OF THE INVENTION

According to teachings of the present invention there is provided an apparatus for sampling and processing at least one hazardous substance within a target volume, the apparatus including: a container having the target volume disposed therein; an adsorption arrangement, including a first sorbent having a first adsorption surface and at least a second sorbent having at least a second adsorption surface, the first and second adsorption swtes being adapted to adsorb gas-phase molecules; a desorption arrangement fImctionally associated with the first sorbent and adapted to effect desorption of gas-phase molecules adsorbed onto the first adsorption surface; and a fluid transfer arrangement adapted and disposed to: withdraw a first gas sample from within the container during a withdrawal mode; deliver the gas sample to the first adsorption surface, during a first sampling mode; and, subsequently, deliver to the second adsorption surface, during a second sampling mode, a second gas sample containing gas phase molecules desorbed from the first adsorption surface.

According to another aspect of the present invention there is provided a method of the sampling and processing of the at least one hazardous substance disposed within the target volume, the method including: sampling the container to produce the first gas sample; contacting the first gas sample with the first adsorption surface to produce a first loaded sorbent; subsequently desorbing material adsorbed to the first adsorption surface to produce the second gas sample containing the gas phase molecules; and contacting the second gas sample, with the second adsorption surface, to produce at least a second loaded sorbent.

According to yet another aspect of the present invention there is provided an apparatus for sampling and processing at least one hnsrdous substance within a target volume, the apparatus including: a container having the target volume disposed therein; an adsorption arrangement, including at least one sorbent having an adsorption suitce adapted to adsorb gas-phase molecules, and a sorbent housing, the sorbent disposed within the housing; a fluid transfer arrangement, adapted and disposed to: withdraw gas from within the container duiing a gas withdrawal mode; and deliver the gas to the adsorption surface, during a sampling mode; the adsorption surface having a characteristic pore diameter of at least 65 micrometers (p.).

According to yet another aspect of the present invention there is provided a method of the sampling and processing of the at least one hanrdous substance within the container or target volume, the method including: sampling the container or target volume to produce a target volume sample; and contacting the sample with the adsorption surface to produce a loaded sorbent.

According to further features in the described preferred embodiments, the container has minimum dimensions of 0.5 meters by 0.5 meters by 0.5 meters.

According to still further features in the described preferred embodiments, at least one of the first and second adsorption surfaces have a characteristic pore diameter of at least 65i, at least 75i, at least 85t, at least 100t, at least 125t, at least tSOM, at least 200M or at least 300R* According to still further features in the described preferred embodiments, the charactenstic pore diameter is at most 35O0i, at most 2000R at most 200R at most l000i, at most 900!i, at most 750!i, at most 650!i, or at most 550R* According to still further features in the described preferred embodiments, the charactenstic pore diameter is within a range of 70 to 500R. 80 to 1500R tOO to 1200R 100 to l000ii, 150 to t200R, 200 to 1200M. 200 to 1000i, 250 to I 2O0, 300 to I 200i, 300 to I O00i, 350 to 1 O00i, 350 to 8O0i, or 400 to I 000t.

According to still further features in the described preferred embodiments, at least one of the first and second sorbents is temperature stable at a lower temperature limit of 0°C and up to an upper temperature limit of at least 70°C.

According to still further features in the described preferred embodiments, the upper temperature limit is 85°C, 95°C, 110°C, 130°C, 150°C, 175°C, or 200°C.

According to still further features in the described preferred embodiments, the apparatus further includes a heating arrangement, adapted to heat the target volume.

According to still further features in the described preferred embodiments, the heating arrangement includes a recirculation loop attached to the container to form an outlet for withdrawing the gas from the container, and an inlet for returning die gas to the container; a recirculation pmnp, fluidly associated with the ioop, and adapted to effect forced circulation of the gas by withdrawing the gas via the outlet and returning the gas to the container via the inlet; and a heating arrangement, associated with the loop, and adapted to heat the gas as the gas transits the recirculation loop.

According to still further features in the described preferred embodiments, the recirculation pump and heating arrangement are controlled such that the gas reintroduced to the container via the inlet has a temperature that exceeds a bulk temperature within the container by at most 40°C, at most 35°C, at most 30°C, at most 25°C, at most 20°C, at most 15°C, or at most 10°C.

According to still further features in the described preferred embodiments, the container is sealed, during the gas withdrawal mode, from an ambient environment.

According to still further features in the described preferred embodiments, the apparatus further includes a pumping arrangement, fluidly associated with the container, and adapted to introduce an external gas to the container.

According to still further features in the described preferred embodiments, the pumping arrangement is adapted and positioned such that the external gas includes, or consists essentially of ambient air.

According to still further features in the described preferred embodiments, at least one of the first and second sorbents has a specific surface area within a range of 0.1 to 50 m2/gram.

According to still further features in the described preferred embodiments, any filtration arrangement for filtering the gas from within the container is disposed downstream of the adsorption arrangement, so as to receive a portion of the gas after the portion has been discharged from the adsorption alTangement.

According to still further features in the described preferred embodiments, at least one of a first gas flow path between the contamer arid the first sorbent, and a second gas flow path between the first and second sorbents, or both flow paths, are free of any gas filtration arrangement.

According to still further features in the described preferred embodiments, the apparatus further includes a ventilating arrangement having a ventilator disposed within the container, and adapted, in a ventilation mode, to mix the gas within the container.

According to still further features in the described preferred embodiments, the container is semi-rigid, at least semi-rigid, or rigid.

According to still further features in the described preferred embodiments, the apparatus further includes a controller, configured to control the fluid transfer arrangement.

According to still further features in the described preferred embodiments, the controller is configured to control the fluid transfer arrangement to periodically attain a sub-atmospheric pressure within the container, during a single sampling run.

According to still further features in the described preferred embodiments, the controller is configured to control the fluid transfer arrangement to periodically attain a super-atmospheric pressure within the container, during a single sampling run.

According to still further features in the described preferred embodiments, the controller is configured to control the fluid transfer arrangement to periodically attain, within the container, a sub-atmospheric pressure, and a super-atmospheric pressure, during a single sampling run.

According to still further features in the described preferred embodiments, the controller is further configured to maintain a maximum pressure within the container below 1.5 atmosphere absolute (ata), below 1.4 ata, below 1.3 ata, below 1.25 ata, below 1.2 ata, below 1.15 ata, or below 1.1 ata.

According to still further features in the described preferred embodiments, the controller is thither configured to control the fluid transfer arrangement to effect at least one operating cycle within a sampling run, wherein, in each cycle of the at least one operating cycle, the container undergoes pressurization from a sub-atmospheric pressure state to a super-atmospheric pressure state.

According to still further features in the described preferred embodiments, the super-atmospheric pressure state includes a peak pressure state, and the sub-atmospheric pressure includes a peak vacuum state, the controller further configured to control the fluid transfer arrangement such that the pressurization from the peak vacuum state to the peak pressure state, or vice versa, within a single cycle of the operating cycle, is achieved over a period of at least 1 second, at least 2 seconds, at least 5 seconds, at least 10 seconds, or at least 20 seconds.

According to still further features in the described preferred embodiments, the super-atmospheric pressure state includes a peak pressure state, and the sub-atmospheric pressure includes a peak vacuum state, the controller further configured to control the fluid transfer alTangement such that a transient pressure gradient (dPldt) within the container is maintained below 1,000 Pals, or within a range of 100 to 1,000 Pals, 150 to 1,000 Pals, 200 to 1,000 Pals, 300 to 1,000 Pa/s, 400 to 1,000 Pa/s, or 200 to 800 Pa/s, within at least one cycle of the operating cycle.

According to still further features in the described preferred embodiments, the controller is further configured to control the fluid transfer arrangement such that a first volume of the fir St gas sample delivered by the fluid transfer arrangement to the fir St sorbent is larger than a second volume of the second gas sample delivered by the fluid transfer arrangement from the first sorbent to the second sorbent, a dimensionless volumetric ratio between the first volume and the second volume being at least 2, at least 4, at least 8, at least 20, at least 50, at least 100, at least 250, at least 500, or at least 1000.

According to still further features in the described preferred embodiments, the container has a total volume Yc, the controller being further configured to control the fluid transfer arrangement such that a dimensionless volumetric ratio of a sampling volume (Vs) of the first gas sample to the first sorbent, to the total volume (Yc), is at least 0.!, at least 0.2, at least 0.3, at least 0.5, at least I, at least 2, at least 3, at least 4, or at least 5.

According to still further features in the described preferred embodiments, the volumetric ratio (VslVc) is at most 10, at most 8, at most 7, or at most 6.

According to still further features in the described preferred embodiments, the controller is further configured to initiate a sterilization mode within the apparatus, following the sampling mode.

According to still further features in the described preferred embodiments, the sterilization mode including heating an internal volume of the container, using at least one heating arrangement, to at least 70°C, at least 85°C, at least 100°C at least 150°C, at least 200°C, at least 250°C, or at least 300°C.

According to still further features in the described preferred embodiments, at least one of the fir st and second sorbents includes, largely includes, or consists essentially of a sorbent fabric.

According to still further features in the described preferred embodiments, the sorbent fabric includes, largely includes, or consists essentially of a matenal selected from the group consisting of rayon fiber and fiberglass.

According to still further features in the described preferred embodiments, the first sorbent includes, largely includes, or consists essentially of sorbent granules.

According to still further features in the described preferred embodiments, the adsorption arrangement includes a first sorbent housing having the first sorbent disposed therein and including a sealed chamber having at least a first port and a second port, the ports fluidly intercommunicating via the chamber, and via the first sorbent.

According to still further features in the described preferred embodiments, at least one of the first and second sorbents includes the sorbent fabric, a compressive strength of the sorbent fabric being at most 3MPa, at most I.OMPa, at most O.5MPa, at most O.3MPa, at most O.2MPa, at most O.1MPa, at most O.O5MPa, or at most O.O2MPa.

According to still further features in the described preferred embodiments, at least one of the first and second sorbeilts includes the sorbent granules, a compressive strellgtll of the sorbeilt granules being at most 1OMPa, at most 5MPa, at most 2MPa, at most 1MPa, at most O.5MPa, at most O.2MPa, at most ft I MPa, or at most O.O5MPa.

According to still further features in the described preferred embodiments, the apparatus further includes a detection arrangement adapted to receive the second sorbent.

According to still further features in the described preferred embodiments, the method further includes exposing at least one of the first and second loaded sorbents to deliver vapor to a biosensor.

According to still further features in the described preferred embodiments, the biosensor is a sniffing dog.

According to still further features in the described preferred embodiments, the method further includes disposing the biosensor within one meter of at least one of the first loaded sorbent and the second loaded sorbent.

According to still further features in the described preferred embodiments, the method further includes delivering the second loaded sorbent to deliver vapor to an instrumental chemical detection system.

According to still further features in the described preferred embodiments, the maximum pressure differential across the first adsorption surface, during the contacting of the sample therewith, is less than 1,000 Pa, less than 800 Pa, less than 600 Pa, less than 500 Pa, less than 400 Pa, less than 300 Pa, less than 200 Pa, less than 150 Pa, or less than 100 Pa.

According to still further features in the described preferred embodiments, the sampling of the container to produce the first gas sample is effected within 3 minutes, within 2.5 minutes, within 2 minutes, within 1.5 minutes, or within 1 minute, while maintaining a maximum pressure differential across the first adsorption surface, during the contacting of the sample therewith, below 1,000 Pa, below 800 Pa, below 600 Pa, below 500 Pa, below 400 Pa, below 300 Pa, below 200 Pa, below 150 Pa, or below 100 Pa.

According to still further features in the described preferred embodiments, the first gas sample has a volume of at least 0. 1m3, at least 0.2m3, at least 0.3m3, at least 0.5m3, at least 0.7m3, at least 1m3, at least 1 Sm3, at least 2m3, at least 3m°, or at least Sm3.

According to still further features in the described preferred embodiments, the method further includes, subsequent to step (e), heating the container to at least at least 70°C, at least 85°C, at least 100°C at least 150°C, at least 200°C, at least 250°C, or at least 300°C, so as to desorb or otherwise remove any of the at least one hazardous substance disposed within the container.

According to still further features in the described preferred embodiments, the hazardous substance includes at least one of trthitrotoluene (TNT) and an explosive nitramine compound.

According to still further features in the described preferred embodiments, the desorbing of material adsorbed to the first adsorption surface is perfonned in at least fir st and second time periods, the second time period being subsequent to the fir st time penod, wherein, in the first time period, the desorbing is effected at a first temperature, and in the second time period, the desorbing is effected at a second temperature, and wherein the secoild temperature exceeds the first temperature.

According to still further features in the described preferred embodiments, at least a fraction of the gas desorbed during the first time period is diverted from contacting the second adsorption surface.

According to still further features in the described preferred embodiments, the second sorbent includes a fir St sorbent unit and a second sorbent unit, and at least a fraction of gas desorbed during the first time period is contacted with the second adsorption surface of the first sorbent unit, and at least a fraction of gas desorbed during the second time period is contacted with the second adsorption surface of the second sorbent unit.

According to still further features in the described preferred embodiments, the second sorbent includes a first sorbent unit and a second sorbent unit, and at least a fraction of gas desorbed during the first time period is contacted with the second adsorption surface of the first sorbent unit, and at least a fraction of gas desorbed during the second time period is contacted with the second adsorption surface of the second sorbent imit, so as to improve chemical selectivity or reduce a concentration of masking agents in the second sorbent unit.

According to still further features in the described preferred embodiments, the sorbent material includes, or consists of a fabnc sorbent.

According to still further features in the described preferred embodiments, the sorbent material includes rayon fiber or fiberglass.

According to still further features in the described preferred embodiments, the compressive strength of the sorbent fabric is at most 3MPa, at most 1.OMPa, at most 0.5MPa, at most 0.3MPa, at most 0.2MPa, at most O.1MPa, at most 0.O5MPa, or at most O.O2MPa.

According to still further features in the described preferred embodiments, the sorbent includes, or consists of sorbent granules.

According to still further features in the described preferred embodiments, the compressive strength of the sorbent granules is at most 1OMPa, at most SMPa, at most 2MPa, at most 1 MPa, at most 0.SMPa, at most O.2MPa, at most 0.1 MPa, or at most O.O5MPa.

According to still further features in the described preferred embodiments, there is provided a method of sampling and processing at least one hazardous substance within a target volume, the method including any feature described, either individually or in combination with any feature, in any configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useflul and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessaiy for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several fonns of the invention may be embodied in practice. Throughout the drawings, like-referenced characters are used to designate like elements.

Inthe drawings: Figure 1 is a schematic ifiustration of an embodiment of an apparatus for sampling and processing hazardous substances within a target volume, constructed and operative in accordance with an embodiment of the teachings herein; Figure 2 is a schematic illustration of a heating arrangement forming part of the apparatus of Figure 1, constructed and operative in accordance with an embodiment of the teachings herein; Figure 3 is a schematic illustration of an embodiment of an adsorption arrangement and a fluid transfer arrangement foiming part of the apparatus of Figure 1, constructed and operative in accordance with an embodiment of the teachings herein; Figure 4 is a schematic illustration of a sorbent chamber forming part of the adsorption arrangement of Figure 3 constructed and operative in accordance with the teachings herein; Figures 5A and SB are images representing the microstructure of two different sorbent matenals which may be used in the adsorption arrangement of Figure 3 and the sorbent chamber of Figure 4, wherein Figure SA represents a sorbent fabric and Figure SB represents sorbent granules; Figures 6A and 6B are schematic represeiltations of exemplary adsorption surfaces used in the adsorption arrangement of Figure 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The principles and operation of the present invention may be better understood with reference to the drawings and the accompanying description.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or calTied out in various ways. Also, it is to be understood that the phraseology and tenninology employed herein is for the purpose of description and should not be regarded as limiting.

Reference is now made to Figure 1, which is a schematic illustration of an embodiment of an apparatus for sampling and processing hazardous substances within a target volume, constructed and operative in accordance with an embodiment of the teachings herein.

As seen in Figure 1, an apparatus 100 for sampling and processing at least one hazardous substance, such as explosive substances (e.g., TNT, RDX, IIDX) includes a container 102 having a target voimne 109 disposed therein. Target voimne 109 may contain a stack or pallet of cartons or suitcases, by way of example. Container 102 may have any suitable dimensions. In some embodiments, however, container 102 has a minimum volume of 0.2 cubic meters and mnrnnmn dimensions of 0.5 meters by 0.5 meters by 0.5 meters. In some embodiments, the target volume of the container is configured to receive at least one object (not shown) to be sampled for the presence of at least one hazardous substance. The objects to be examined may be introduced and removed from container 102 via a door 104. Container 102 and door 104 may be adapted to be sealable from an ambient environment.

In some embodiments, a ventilator 106 is disposed within container 102 and may be adapted to mix gas present within container 102 prior to and/or during withdrawal of the gas from the container. In some embodiments, a pressure sensor or meter 108 is functionally associated with container 102 and is configured to measure the pressure therein. In some embodiments, pressure meter 108 is mounted on container 102 at a location visible to a human operator of apparatus 100.

Functionally associated with container 102 is an adsorption and fluid transfer arrangement 110, whose components and functionality are described in further detail hereinbelow with reference to Figures 3 -6B.

In some embodiments, a heating arrangement 116 is functionally associated with container 102, and may be adapted to heat the gas within container 102, and more specifically, the gas within target volume 109, prior to and/or during withdrawal of the gas from container 102, and/or during sterilization thereof The components and functionality of heating alTangement 116 are described hi further detail hereinbelow with reference to Figure 2.

A pumping arrangement 118, such as an overpressure blower, is fluidly associated with container 102 via a valve 120, and is adapted to introduce an external gas, such as ambient air, into container 102, while valve 120 is open, e.g., during a withdrawal mode (or a portion thereof), and typically but not exclusively, in a sampling mode.

In some embodiments, a controller (similar or substantially identical to controller 350 shown in Figure 3) is functionally associated with pumping arrangement 118, and may be configured to control fluid flow into and out of container 102, as is described in further detail hereinbelow.

Reference is now made to Figure 2, which is a schematic illustration of heating arrangement 116 forming part of the apparatus of Figure 1, constructed and operative in accordance with an embodiment of the teachings herein.

Heating arrangement 116 may include a recirculation loop 200, attached to container 102 at an outlet 202 for withdrawing gas from container 102 and at an inlet 204 for returning the gas, following heating thereof, to container 102. Flow of gas through outlet 202 may be controlled by an outlet valve 206 and flow of gas through inlet 204 may be controlled by an inlet valve 208, as described in further detail hereinbelow.

During recirculation or recirculation mode, a recirculation pump or blower 210 is in fluid communication with recirculation loop 200, and is adapted to effect forced circulation of gas from container 102 by withdrawing die gas from container 102 via outlet 202 and returning the heated gas to container 102 via inlet 204.

A heating element 212 may be in fluid communication with recirculation loop 200, and may be adapted to heat the gas withdrawn from container 102 as the gas transits recirculation loop 200. In some embodiments, a thermostat (not shown) is functionally associated with heating element 212, such that the heating temperature of the gas passing through the heating element 212 can be controlled by a controller 240 (or controller 350 shown in Figure 3) or by an operator of the apparatus 100.

A conduit 214 disposed downstream of heating element 212 may include, or be connected to, a recirculation branch 216 adapted to reintroduce heated gas to container 102, via inlet 204. Conduit 214 may be further connected to an exhaust pipe branch 218 associated with a valve 220 and adapted for selectively removing gas from recirculation loop 200, as will be described hereinbelow. In some embodiments, recirculation branch 216 has functionally associated therewith a thermocouple port 222, adapted for enabling control of the temperature of gas reintroduced into container 102 via inlet 204.

Arrows 224, 226, 228, and 230 indicate the gas flow direction through recirculation loop 200, where alTow 228 indicates reintroduction of gas to container 102 via recirculation branch 216, and anow 230 indicates removal of gas from recirculation loop 200 via exhaust pipe branch 218.

In some embodiments, a recirculation and heating controller 240 is functionally associated with recirculation pinup 210 and/or with heating element 212, and is adapted to control the volume of gas drawn from container 102, the volume of gas reintroduced into container 102, the temperature to which heating element 212 heats the gas passing therethrough, and/or the orientations (e.g., degree of opening) of valves 206, 208, and 220.

Reference is now made to Figure 3, which is a schematic illustration of an embodiment of an adsorption arrangement and a fluid transfer arrangement forming part of the apparatus of Figure 1, constructed and operative in accordance with an embodiment of the teachings herein.

As seen in Figure 3, adsorption and fluid transfer arrangement 110 of Figure 1 includes an outlet 302 fluidly associated with container 102 for withdrawal of gas therefrom. An outlet valve 304 is functionally associated with outlet 302, and is configured to close the outlet 302 upon demand, as described in further detail hereinbelow.

A sorbent chamber 306 is in fluid flow communication with outlet 302 via valve 304 and a conduit 307. As seen in Figure 4, which is a schematic illustration of sorbent chamber 306, sorbent chamber 306 has a sorbent housing 400 including an inlet port 402 which may be in fluid flow communication with outlet 302 of container 102, and through which gas from container 102 can enter sorbent housing 400.

In some embodiments, sorbent housing 400 is sealed from the environment. Inside sorbent housing 400 may be disposed a sorbent 406, which may have an adsorption surface adapted to adsorb gas-phase molecules of hazardous substances. Sorbent 406 allows fluid flow communication between an upper portion 408 of housing 400 above the sorbent 406 and a lower portiou 410 of the housing 400 below the sorbent 406. In some embodiments, sorbeut 406 is supported in sorbent housing 400 by a permeable support element 412, such as a support net or a perforated pan or container. An outlet port 414 is fluidly associated with lower portion 410 of sorbent housing 400 and is adapted for discharging gas that has passed through sorbent 406.

Functionally associated with sorbent housing 400 is a heating chamber 420 including a heating element 422, which is adapted for heating sorbent 406 to affect desorption of substances adsorbed thereto, as will be described in further detail hereinbelow. In some embodiments, heating chamber 420 is formed of a material having high thermal conductivity, such as aluminum or copper.

In some embodiments, sorbent 406 includes a large, typically non-disposable sorbent, having a large adsorbing surface area. In some embodiments, sorbent 406 has a specific surface area within a range of 0.I to 50 m2/gram.

While any suitable type of sorbent may be used for implementation of the teachings herein, in some embodiments, sorbent 406 includes, largely includes, or consists essentially of a sorbent fabric. In some such embodiments, sorbent 406 may be made oL or include, rayon fibers and/or fiberglass. One exemplary matenal is a viscose rayon (or simply rayon), which is a fiber that may be made from regenerated wood cellulose. In an exemplary embodiment, the specific surface area is 0.3m2/g, and the viscose rayon is manufactured by Kelheimn Fibers (GmbH).

In some embodiments, sorbent 406 includes sorbeiit granules (e.g., pellets). Various such granules are commercially available, e.g., Tenax® Porous Polymer Adsorbents (Sigma-Aldrich® Co. LLC --Supelco) based on 2,6-diphenyl-p-phenylene oxide, having a nominal particle size of 60-80 mesh, and a specific surface area of 35m2/g.

Figures SA and SB illustrate the microstructure of a sorbent fabric and of sorbent granules, respectively. As seen in Figure 5A, a sorbeilt fabric 406 has multiple fibers having pores or open spaces therebetween. As shown in Figure 6A, a sorbent fabnc (e.g., as shown in Figure 5A) includes niacrofibers or strands 605 having a characteristic diameter d, and pores or open spaces 604 having a characteristic pore diameter Dporo. Each of strands may include a plurality of individual fibers. Gas phase molecules, such as gas phase molecules of hazardous substances, may be adsorbed onto the surface, e.g., between the individual fibers making up strands 605. The permeability of sorbent 406 may be largely dependent on the characteristic pore diameter In some embodiments, it is desirable that D0 will be significantly greater than characteristic diameter d (Dpore>> d).

The penneability of sorbent 406, or the characteristic pore diameter (Dj)Qre) of pores therein, may be of any suitable magnitude. In some embodiments, such as embodiments in which it is desired that particles, such as dust particles, pass through the sorbent without appreciable clogging of sorbent 406 or preventing adsorption of gas-phase molecules on the adsorption surface of the sorbent, the adsorption surface has a characteristic pore diameter D1)ore of at least 65 micrometer (p).

Figure 6B provides a schematic representation similar to that of Figure 6A, but having microporous sorbent fibers 602. Microporous sorbent fibers 602, e.g., made of; or including, activated carbon, have a characteristic diameter d, and pores or open spaces 604 having a characteristic pore diameter Gas phase molecules, such as gas phase molecules of hazardous substances, may be adsorbed onto the surface of microporous fibers 602. The permeability of sorbent 406 may be largely dependent on the characteristic pore diameter In some embodiments, it is desirable that DpOft will be significantly greater than characteristic diameter d (Dpore >> d). The permeability characteristics may be substantially identical to those described above, and the characteristic pore diameter D1)0, as above, may be at least 65 micrometer (j4.

In some embodiments, the characteristic pore diameter Dpore is at least 75F1, at least 85t, at least lOOi, at least l25i, at least l5Oi, at least 2OOi, or at least In some embodiments, the characteristic pore diameter Dpore is at most 35OO, at most 2000ii, at most 1200!1, at most 1OOOi, at most 9OOi, at most 75Ot, at most 65Ot, or at most 550!k.

In some embodiments, the characteristic pore diameter Dpom is within a range of 70 to 1500!k, 80 to l50Ot, 100 to 1200R. 100 to 1000R 150 to 1200R to 200R. 200 to l000ii, 250 to I200it, 300 to 1200M. 300 to l000!i, 350 to 1000!k, 350 to 800!k, or 400 to 1000R* In some embodiments, sorbent 406 is temperature stable at a lower temperature limit of 0°C and up to an upper temperature limit of at least 70°C. In some embodiments, the upper temperature for sorbent stability limit is 85°C, 95°C, 110°C, 130°C, 150°C, 175°C, or 200°C.

In some embodiments, for example, when sorbent 406 is a fabric, sorbent 406 may have a compressive strength of at most 3MPa, at most 1.OMPa, at most 0.SMPa, at most 0.3MPa, at most 0.2MPa, at most 0.1MPa, at most 0.OSMPa, or at most 0.O2MPa.

In some embodiments, for example, when sorbent 406 is granular or the like, sorbent 406 may have a compressive strength of at most I OMPa, at most SMPa, at most 2MPa, at most IMPa, at most 0.SMPa, at most 0.2MPa, at most 0.1 MPa, or at most 0.OSMPa.

In some embodiments, sorbent 406 is configured to have large volumes of gas pass therethrough, in some embodiments without becoming clogged and/or without saturating the adsorption surface.

Returning to Figure 3, it is seen that outlet 414 of sorbent chamber 306 is in fluid flow communication with a conduit 308 having a branch 310 that is in fluid flow communication with an ambient eiiviromnent via a valve 312. A distal end of conduit 308 is in fluid flow communication with an neutralizrng vessel 316 via a valve 318.

During operation, neutralizing vessel 316 may be partially filled with a suitable liquid 320 or neutralizing agent, as will be known to those of skill in the art. In some embodiments, liquid 320 includes at least one neutralizing substance and is adapted to neutralize hazardous or harmful substances present in the gas discharged from conduit 308. In some embodiments, the neutralizing substance includes one or more of Fenton's reagent (a solution of peroxide and an iron catalyst), hypochlorite (e.g, sodium or potassium hypochiorite), pennanganate (e.g., sodium or potassium pennanganate).

The level of liquid 320 may advantageously be maintained such that a fluid withdrawal element 326, such as a vacuum pump, may fluidly communicate with a gas-filled portion 324 of neutralizing vessel 316, via a conduit 322.

Typically, vacuum pump 326 may fluidly communicate with the ambient environment via an exhaust pipe 328.

Using any of the apparatus embodiments described herein, an inventive method of sampling and processing hazardous substances disposed within a target volume may include sampling the target volume to produce a target volume sample; and contacting the sample with an adsorption surface to produce a loaded sorbent.

In some embodiments, the loaded sorbent may be exposed so as to deliver vapor to a biosensor such as a sniffing dog, the vapor containing desorbed gas from the loaded sorbent. To this end, the biosensor may be disposed within one meter of the loaded sorbent, or within one meter of a point where the vapor is discharged to the ambient environment.

Alternatively or additionally, the vapor may be delivered to an instrumental chemical detection system.

In another aspect of the present invention, the adsorption within sorbent housing 401) (effected by sorbent 406) in a first stage or structure of adsorption L.) 305, which is followed by a controlled desorption step; the desorbed vapor is introduced to a second stage or structure of adsorption 330. Second stage 330 includes at least one adsorption unit 342 containing at least one individual sorbent column or housing 343, each adapted to contain a sorbent 345. Second stage 330 is adapted to fluidly conimumcate with first stage 305 via a conduit 344, when a valve 347 disposed within conduit 344, between first and second stages 305, 330, is disposed in an at least partially open position.

Valve 347 may be optional. The function of valve 347 may be effected in other ways, for example, using a valve 348 disposed within a conduit 346, connected to, and downstream of, second stage 330. Conduit 346 may be disposed, at an end distal to second stage 330, within neutralizing vessel 316.

Between first and second stages 305, 330, e.g., within or around conduit 344, may be disposed a heating element 340. Heating element 340 may be adapted to heat conduit 344 and the surrounding elements of the apparatus, so as to "sterilize" (i.e., eliminate traces of the adsorbed organic molecules, or appreciably reduce the concentration thereof') this section of the apparatus.

It will be appreciated that outlet 302, sorbent chamber 306, and adsorption units 342 are all in fluid flow communication with vacuum pump 326 via valves 304, 318, and 348, such that vacuum pump 326 is adapted to withdraw gas from container 102 via outlet 302, sorbent chamber 306, and/or adsorption units 342, as will be described in thrther detail hereinbelow.

While any suitable type of sorbent may be used in adsorption units 342, sorbent 345 typically includes, or consists of, a sorbent fabric.

The permeability of sorbent 345, and die characteristic pore diameter Dpore of pores therein, may be of any suitable magnitude.

At least one controller, such as fluid transfer controller 350, may be functionally associated with valve 304, valve 312, valve 318, vacuum pump 326, heating element 340, valve 347, and valve 348. Controller 350is adapted to control fluid transfer through adsorption and fluid transfer arrangement 110 as described in further detail hereinbelow. In some embodiments, fluid transfer controller 350 is also functionally associated with pumping arrangement 118, and is then adapted to control fluid transfer into, within, and out of container 102 via pumping arrangement 118 and adsorption and fluid transfer arrangement 110.

In use, apparatus 100 may operate in various operational modes, including a gas withdrawal mode, at least one sampling mode, such as a first sampling mode and a second sampling mode, and a post-processing, or sterilization, mode.

Apparatus 100 may operate in a controlled desorption mode, but this may usually effected as part of the second sampling mode. The various modes are further elaborated hereinbelow.

Prior to the gas withdrawal and first sampling modes, one or more objects to be sampled for the presence of hazardous substances is inserted into container 102, and may be sealed therein from an ambient environment, typically by closing door 104. Ventilator 106 may be activated in a ventilation mode, and in some embodiments, remains activated for die duration of the sampling mode.

Gas withdrawal mode and first sampling mode may be largely identical.

During gas withdrawal mode, and typically during first sampling mode, heating controller 240 maintains valve 220 leading to exhaust pipe 218 in a closed orientation. Heating controller 240 also controls withdrawal of gas from container 102 into recirculation loop 200 via outlet 202, and heating the gas by heating element 212 to a suitable temperature prior to reintroducing the gas into container 102 via inlet 204. In some embodhnents, recirculation and heating of the gas in container 102 are continuously controlled by heating controller 240 throughout operation of apparatus 100 in the gas withdrawal mode and first sampling mode.

Heating controller 240 may initiate operation of recirculation loop 200 and heating element 212 before commencing withdra\val of gas from container 102 via outlet 302.

In some embodiments, heating controller 240 is configured to control the heating element 212 and recirculation loop 200 such that gas reintroduced into container 102 via inlet 204 has a temperature that exceeds the bulk temperature within container 102 by at most 40°C, at most 35°C, at most 30°C, at most 25°C, at most 20°C, at most 15°C, or at most 10°C.

Controller 350 may be configured to open valve 120, thereby allowing fluid flow from pumping arrangement 118 into container 102. Following a control command from controller 350, pumping arrangement 118 may introduce external gas into container 102, and subsequently controller 350 closes valve 120, resulting in super-atmospheric pressure within container 102. In some embodiments, the external gas introduced into container 102 by piunping arrangement 118 includes, or consists essentially of ambient air.

Following production of super-atmospheric pressure in container 102, controller 350 opens valves 304 and 318, closes valve 348, and provides a command for activation of vacuum pump 326. Vacumn pump 326 withdraws gas from container 102, and due to the orientations of the valves and the structure of apparatus 100, the withdrawn gas travels through conduit 307 and port 402 into sorbent chamber 306, where the gas passes through sorbent 406 and organic substances are adsorbed onto the sorbent.

Alternatively, the initial withdrawal of gas from container 102 may bc performed from an initial state at, or around, ambient or atmospheric pressure.

Gas passing through sorbent 406 is withdrawn from sorbent chamber 306 via lower portion 410, outlet port 414 and conduit 314, and may be discharged to the environment. In some embodiments, the gas may first be passed through liquid 320 of neutralizing vessel 316. The gas bubbles up from liquid 320 into gas filled portion 324 of vessel 316, and from there, the treated gas may be withdrawn by vacuum pump 326, via conduit 322, and may be discharged from the apparatus via exhaust pipe 328.

In some embodiments, as the withdrawn gas bubbles through liquid 320 and into gas filled portion 324 of vessel 316, any hazardous substances not adsorbed by sorbent 406 and still present in the withdrawn gas are neutralized by the neutralizing substance in liquid 320.

Following withdrawal of gas from container 102 by vacuum pmnp 326, a sub-atmospheric pressure exists within container 102.

In some embodiments, during a single sampling run of apparatus 100, controller 350 is configured to control pumping arrangement 118 and adsorption and fluid transfer alTangement 110 as descnbed hereinabove to effect an operating cycle so as to periodically obtain cycles of super-atmospheric pressure within container 102 followed by sub-atmospheric pressure within container 102.

In some embodiments, controller 350 is configured to maintain a maximum pressure within container 102 below 1.5 atmosphere absolute (ata), below 1.4 ata, below 1.3 ata, below 1.25 ata, below 1.2 ata, below 1.15 ata, or below 1.1 ata.

In some embodiments, a super-atmospheric pressure state of container 102 includes a peak super-atmospheric pressure state, and a sub-atmospheric pressure of container 102 including a peak vacuum state. In such embodiments, controller 350 is configured to control pumping arrangement 118 and/or adsorption and fluid transfer arrangement 110 such that pressurization from the peak vacuum state to the peak pressure state, or depressurization from the peak pressure state to the peak vacuum state is achieved over a period of at least 1 second, at least 2 seconds, at least 5 seconds, at least ID seconds, or at least 20 seconds.

In some embodiments, controller 350 is further configured to control pumping arrangement 118 and/or adsorption and fluid transfer arrangement 110 such that an absolute value of the transient pressure gradient (dP/dt) within container 102 between the peak pressure state and the peak vacuum state, or between the peak vacuum state and the peak pressure state, is maintained below 1,000 Pals, and more typically, within a range of 100 to 1,000 Pals, 150 to 1,000 Pals, 200 to 1,000 Pals, 300 to 1,000 Pa's, 400 to 1,000 Pa/s, or 200 to 800 Pa/s.

The volume of gas withdrawn by vacuum pump 326 during the operation cycles may be any suitable volume of gas. In some embodiments, controller 350 is configured to control pumping arrangement 118 and vacuum pump 326 such that the volmne of gas withdrawn by vacuum pmnp from container 102, and passed though sorbent 406, is at least 0.4, at least 0.6, at least 0.8, at least 1, at least 2, at least 3, at least 5, at least 8, or at least lOin3.

In some embodiments, controller 350 may be further configured to control the fluid transfer arrangement such that a dimensionless volumetric ratio of a sampling volume (Vs) of the withdrawn gas delivered by the fluid transfer arrangement to first sorbent 406, to a total (internal) volume of container 102 (Vc), is at least 0.1, at least 0.2, at least 0.3, at least 0.5, at least 1, at least 2, at least 3, at least 4, or at least 5.

In some embodiments, this volumetric ratio (Vs/Vc) is at most 10, at most 8, at most 7, or at most 6.

Following withdrawal of a suitable volume of gas from container 102, controller 350 is configured to close valves 304 and 318, and to open valves 347, 348, and 312, to enable a second adsorption (or a readsorption) phase as described herein. At this stage, sampling from container 102 is complete, the container can be unsealed, such as by opening door 104, and the target object(s) may be removed from the container.

Following reorientation of valves 304, 318, 312 and 348, heating element 422 of sorbent chamber 306 may be activated or controlled to heat sorbent 406 SO as to effect at least partial desorption of organic molecules adsorbed thereto.

In some embodiments, heating is affected for at most 1 minute, at most 30 seconds, at most 20 seconds, at most 15 seconds, or at most 10 seconds, such that appreciable desorption from the surface of sorbent 406 transpires.

Subsequently or concurrently, controller 350 is configured to activate vacuum pump 326, such that the vapor is withdrawn from sorbent housing 400 via port 402 and coiiduits 307 and 344 into adsorption units 342.

The vapor passes through adsorption units 342, such that organic molecules that had been desorbed from sorbent 406 are now adsorbed by sorbents contained in adsorption units 342, resulting in one or more loaded sorbents. The vapor not adsorbed within adsorption units 342 is withdrawn from the columns via conduit 346 and valve 348 into liquid 320 of vessel 316. As mentioned hereinabove, the vapor bubbles up from liquid 320 into gas filled portion 324 of vessel 316, and from there is withdrawn by vacuum pump 326 via conduit 322 and is removed from the apparatus via exhaust pipe 328. In some embodiments, as the withdrawn vapor bubbles through liquid 320 and into gas filled portion 324 of vessel 316, any hazardous substances not adsorbed by sorbent 406 and still present in the withdrawn vapor are neutralized, oxidized, or otherwise deactivated by the neutralizing, oxidizing, or deactivating substance in liquid 320.

The volume of vapor passing through adsorption units 342 may be any suitable volume. However, it will be appreciated that the desorption from sorbent 406 may be calTied out at a relatively high temperature and with a relatively small volmne of vapor, with respect to the desorption occurring within container 102.

Thus, in some embodiments, controller 350 is configured to control vacuum pump 326 such that a fir st volume of the withdrawn gas delivered by the fluid transfer arrangement to the first sorbent is larger than a second volume of the gas sample delivered by the fluid transfer arrangement from the first sorbent to the second sorbent. A dimensionless volumetric ratio between the first vohune and the second volume may be at least 2, at least 4, at least 8, or at least 12, and more typically, at least 20, at least 50, at least 100, at least 250, at least 500, or at least 1000.

Following transit of the vapor through adsorption units 342, the loaded sorbents are analyzed for detection of hazardous substances adsorbed thereto.

In some embodiments, the loaded sorbents are removed from adsorption units 342 and are provided to a biosensor, such as a sniffing dog, for delivery of vapor thereto and for detection of hazardous substances by the biosensor. In some embodiments, the biosensor is disposed within a small distance, such as one meter, of the loaded sorbent, while the loaded sorbents are within adsorption units 342. It will be appreciated that in some embodiments, the biosensor may be disposed within a small distance, such as one meter, of sorbent housing 400, and sorbent housing 400 may be unsealed, such as by a window or shutter (not shown), to expose loaded sorbent 406 to the biosensor for delivery of vapor thereto.

In some embodiments, the loaded sorbents are removed from sorbent adsorption units 342 and are provided to an instrumental chemical detection system (not shown), such as, for example, a mass spectrometer.

In some embodiments, the apparatus may be adapted, and/or operated, so as to enable selective adsorption of gas-phase molecules that tend to desorb at high temperature, due to equilibrimn andlor kinetic behavior. For example, various masking agents tend to desorb at lower temperatures thau many of the hazardous or explosive substances of interest. The inventors have discovered that by maintaining sorbent 406 below a particular temperature, much of the masking agents adsorbed iu sorbent 406 may be desorbed/driven off, leaving a higher ratio of adsorbed hazardous materials to masking agents in sorbent 406. Thus, the initial, lower-temperature desorption step may be performed while adsorption units 342 are disconnected from sorbent chamber 306, or while a particular adsorption unit of adsorption units 342 is connected to sorbent chamber 306, while at least a second adsorption unit of adsorption units 342 is disconnected from sorbent chamber 306. Subsequent to the initial, lower-temperature desorption step, the at least second adsorption unit of adsorption units 342 may be connected to sorbent chamber 306. Sorbent 406 may then be heated above the above-described particular temperature, such that a higher ratio (with respect to the initial ratio) of adsorbed hazardous materials to masking agents is desorbed from sorbent 406, and is adsorbed by second adsorption unit of adsorption units 342.

In some embodiments, sorbent 345 and/or adsorption units 342, may be subjected to preliminary cooling or freezing, prior to passing the desorbed vapors through conduit 344. The lower temperature may favor increased adsorption of these desorbed vapors.

Subsequently, the apparatus may be prepared for the next run. Before a new target object (e.g., a new pallet having a plurality of cartons or suitcases) is introduced to container 102, a post processing, or sterilization mode may be implemented. In this mode, container 102 is emptied of any objects contained therein (if such emptying has not yet transpired), and in some embodiments, container 102 remains unsealed so that gas from the ambient enviromnent may enter the contuner. Ill some embodimeilts, the contarner may remain sealed or substantially sealed, until after the temperature in the container has risen to a minimum threshold temperature (e.g., 70°-80°C) for a minimum period (e.g., 30 seconds). In some embodiments, pumping arrangement 118 is fluidly disconnected from container 102 by closing valve 120, and/or adsorption and fluid transfer arrangement 110 is disconnected from container 102 by dosing valve 304. In some embodiments, only recirculation loop 200 is operative during the sterilization mode, at east until the minimum threshold temperature has been achieved in container 102.

In some embodiments, ventilator 106 is activated, and in some embodiments remains activated for the duration of the sterilization mode.

After container 102 has been substantially decontaminated, container 102 may be ventilated by recirculation pump or blower 210 withdrawing gas from container 102 so that fresh air may be introduced into container 102 through open door 104 or through another inlet. The gas withdrawn by recirculation pump may be removed from the apparatus via exhaust pipe 218 and (open) valve 220.

Subsequently, valve 220 and door 104 are closed, disconnecting recirculation loop 200 from the ambient environment. Recirculation pump 210 withdraws gas from container 102, the withdrawn gas is heated by heating element 212, and is reintroduced into container 102 via conduit 216 and inlet 204.

This process is repeated until the inside volume of container 102 reaches a desired sterilization temperature and/or until a desired duration has passed.

It will be appreciated that the desired sterilization temperature and the desired sterilization duration may vary depending on the level of contamination of container 102, for example as detected by a biosensor during the sampling mode. In some embodiments, the sterilization temperature is at least 80°C, at least 90°C, at least 100°C, at least 150°C, at least 200°C, at least 250°C, or at least 300°C. In some embodiments, the sterilization duration is at least 30 seconds, at least 60 seconds, or at least 120 seconds, and typically less than 10 minutes, less than 7 minutes, or less than 5 minutes.

In some embodiments, following sterilization of container 102, the level of sterility of the container is tested, for example by carrying out a sampling cycle without inserting any object into container 102 or by swabbing a surface of the container 102 or of condthts of recirculation loop 200.

While various operations have been described as being controlled by a controller, it will be appreciated by those of skill in the art that such operations may be controlled by a human operator, or by a human operator having access to various system parameters (e.g., on a computer display).

As used herein in the specification and in the claims section that follows, the term "percent", or "%", refers to percent by weight, imless specifically indicated otherwise.

Similarly, the term "ratio", as used herein in the specification and in the claims sectioll that follows, refers to a weight ratio, unless specifically indicated otherwise.

As used herein in the specification and in the claims section that follows, the tenn "fluidly communicating with", "fluidly associated with", "in fluid communicatioll with", "in fluid flow communication with", and the like are meant to describe a state between two sections of an apparatus, when any intervening valves are in an at least partially open state.

As used herein in the specification and in the claims section that follows, the term "desorption" and the like refers to a process that is substantially the opposite from adsorption.

As used herein in the specification and in the claims section that follows, the term "neutralizing substance", and the like is meant to include an oxidizing substance.

As used herein in the specification and in the claims section that follows, the term "pore size" or "pore diameter" is determined according to a bubble test for pore size determination, ASTM F316-06 (2011). While the maximum pore size determined by this method may be about IS microns, in determining the porosity in fibrous or packaging materials, the maximum pore size determined by this method may be about 250 microns (ASTM F2096).

It will be appreciated that certain features of the invention, which are, for clarity, described hi the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

Although the invention has been described in conjunction with specific embodiments thereof; it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and vanations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification, including U.S. Patent No. 6,324,927, are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available

as prior art to the present invention.