CN101400982A

CN101400982A - A contraband sampling system with a preconcentrator filter having a thermally conductive frame

Info

Publication number: CN101400982A
Application number: CNA2007800091935A
Authority: CN
Inventors: 凯文·J·佩里; 马修·E·纳普
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2006-03-21
Filing date: 2007-03-21
Publication date: 2009-04-01

Abstract

The present invention provides methods for detecting particles during inspection. The method includes establishing a security checkpoint with a detection system including a chamber defining a passageway and having a plurality of orifices. The method also includes passing the individual through the channel; enhancing a convective column containing particles from the individual by blowing air through at least one of a plurality of orifices; adsorbing the particles in a pre-concentrator comprising an embedded Filter in high thermal conductivity frame. Additionally, the method includes evaporating particles adsorbed in the pre-concentrator and using a detector to determine whether the particles are from at least one of an explosive substance and an intoxicating substance.

Description

Employing has the contraband sampling system of the preenrichment filtrator of thermally conductive frame

The cross reference of related application

The U.S. Provisional Application No.60/784 that the application relates on March 21st, 2006 and submits to, the U.S. non-provisional application No.11/687 that on March 16th, 413 and 2007 submitted to, 063, and require their right of priority, be incorporated herein its full content as a reference.

Background of invention

Present invention relates in general to the system and method for particle detection, particularly, relate to the system and method for surveying nanogram level particle.

There is the terrorism crisis in position in traffic transporting facility, government house and other stream of people or wagon flow dense distribution always.Therefore, present most of airport and many government houses comprise the device of surveying the trace explosive.These devices usually can be transferred to principle work on the person's that carries the explosive health, clothes and the luggage based on a small amount of explosive substance.Usually, known trace door system (traceportal system) uses graded metal mesh to collect sample.Yet graded metal mesh is easy to lose collection efficiency owing to dirty easily with stopping up.

Some detectors adopt can be from the small-sized flexible fabric shape gatherer that wraps up or single-piece luggage was wiped away.Gatherer is removed residue from parcel or luggage surface.Then gatherer is placed for example ion trap mobility spectrometer devices such as (ion trap mobility spectrometer), the residue on the gatherer is carried out the detection of trace explosive substance.This type of device is in U.S. Patent No. 5,491, and is open and by GE Ion Track in 337, Inc.of Wilmington, and Massachusetts puts goods on the market.These devices use at airport next-door neighbour metal detector usually, and the security staff is based on grab sample or meet certain judgement of strengthening fluoroscopy (enhanced screening) standard based on the passenger a part of passenger is carried out fluoroscopy.

In U.S. Patent No. 5,491, disclosed ion trap mobility spectrometer can also be to survey the pattern work of trace arcotic in 337.Arcotic is illegal and has potential danger.In addition, well-known many terroristic organizations therefrom make a profit the funds of its terrorist action are provided by peddling arcotic.

Trace explosive or arcotic that the luggage that only has the part airline passengers to carry has accepted to use textile-like gatherer and available ion trap mobility spectrometer or similar device to carry out detect.Use this type of device to all with oneself parcel carry out the trace explosive or arcotic detects the time and the cost burden that will increase aircraft industry.In addition, above-mentioned explosive detection device only is used for luggage and other parcels usually.This type of device can't be discerned and be worn in passenger's plastic explosive on one's body of not carrying luggage.These mentioned devices have low sensitivity and processing power.

For the above reasons with other reasons discussed below (by reading and to understand the present invention apparent for those skilled in the art), exist mentioned these to install unsolved needs, the verifying attachment of the sensitivity that the illegal material (such as but not limited to arcotic and explosive) that the passenger is carried has raising and the device with processing power of raising are provided.

Summary of the invention

Should be understood that by reading and understanding following content the application solves above-mentioned shortcoming, deficiency and problem.

The described embodiment of the application provides high sensitivity and high throughput.More specifically, the described embodiment of the application provides the detector that comprises a plurality of spouts and has screen cloth and the preconcentrator of filtrator.Spout blows to individuality (individual) driving away the particle on individual clothes and the skin with air, thereby improves the concentration of entrained particles in the individual convection column (convention plume).

Surround screen cloth by the useful area of increase preconcentrator and with framework, shorten evaporation from the required time of the particle of individual convection column with high thermal conductivity.Thereby the described embodiment of the application adopts the detector with high sensitivity and high throughput, with fast, accurately and discern effectively that the passenger carries illegal and have the material of potential danger.

On the one hand, be provided at the method for particle detection in the checkout procedure.This method comprises sets up the security check point with detection system, and wherein detection system comprises the chamber that limits passage and have a plurality of spouts.This method also comprises: individuality is passed through from passage; By via at least one air blowing in a plurality of spouts, strengthen the convection column that comprises from the particle of individuality; And particle is adsorbed in the preconcentrator, this preconcentrator comprises the filtrator that is embedded in the high-termal conductivity framework.In addition, this method comprises: evaporation is adsorbed on the particle in the preconcentrator and adopts detector to judge whether at least a from explosive substance and the narcotic substance of described particle.

On the other hand, be provided for shortening the manufacture method of the preconcentrator of desorption time.This method comprises: form framework, this framework has the four edges that limits opening; Filtrator is positioned on the opening in the framework; And each the bar limit in the corresponding sides of the filtrator bending framework four edges, its middle frame has high temperature conductivity.

Again on the one hand, provide the system of particle detection.This system comprises chamber, a plurality of spout, preconcentrator, detector and controller.Described chamber comprises passage, and controller is used to judge whether individuality is positioned at passage.A plurality of spouts are positioned at indoor, and dispose described a plurality of spout, so that at least one in described a plurality of spout blow to air on the individuality in the passage, comprise convection column from the particle of individuality with enhancing.Preconcentrator comprises the filtrator that is embedded in the heat-conducting plate, and wherein said filtrator is used for granule for absorbing and described detector is used to judge whether particle is at least a of explosive substance and narcotic substance.

Again on the one hand, be provided at the device of particle detection in the checkout procedure.This device comprises the preconcentrator that is used to shorten desorption time, and wherein said preconcentrator comprises the filtrator that is embedded in the heat conducting frame.

Description of drawings

Fig. 1 is the synoptic diagram of the embodiment of detection system.

Fig. 2 is the isometric drawing of embodiment of the preconcentrator of detection system.

Fig. 3 is another isometric drawing of preconcentrator.

Fig. 4 is an isometric drawing again of preconcentrator.

Fig. 5 is the top view of preconcentrator.

Fig. 6 is the side view of preconcentrator.

Fig. 7 is the synoptic diagram of embodiment of the screen cloth of preconcentrator.

Fig. 8 is the top view of the embodiment of preconcentrator.

Embodiment

Fig. 1 is the synoptic diagram of the embodiment of detection system 10.Detection system 10 comprises the passage 14 that extends within it.Detection system 10 is installed on the security check point, and the size of passage 14 is convenient to hold the people of expectation by the security check point.Detector 20 systems 10 also comprise chamber 15.

Heated by human body with the contiguous boundary layer air of people and usually than apart from people's surrounding air heat at a distance.The cold air that the density of hot-air is lower than cold air and relative density is bigger rises.Therefore, with the contiguous borderline region of people in rise tangible human body hot-air convection post.Human convection plume has the flow velocity of 50-100 liter/second usually.A large amount of particles are often carried in obviously flowing of human convection plume secretly, for example the skin of the people by passage 14 or the particle of explosive substance on the clothes or narcotic substance.Thereby microscopic particle is along with human convection plume is upwards advanced.

Detection system 10 comprises a plurality of air ports 16, and described spout makes very brief air-flow blow to people in the passage 14.Spout 16 alignings are roughly from pin extension human region to the end, and the auxiliary particle of driving away on human body skin and the clothes, with the concentration of separating and improve in human convection plume entrained particles of promotion particle with skin and clothes.Detection system 10 also comprises compressed air source 17, controls this compressed air source 17, thereby as U.S. Patent No. 6,708, starts spout described in 572 from bottom to top in turn.Yet, also can adopt other spout start modes.

Detection system 10 also comprises controller 18, preconcentrator 19 and detector 20.The example of detector 20 comprises as U.S. Patent No. 5,491, the ion trap mobility spectrometer described in 337.Detection system 10 comprises that also actuator 22 is as motor and desorption device 24.Controller 18, actuator 22, preconcentrator 19, desorption device 24 and detector 20 are positioned at chamber 15.Perhaps, controller 18, actuator 22, preconcentrator 19, desorption device 24 and detector 20 are positioned at outside the chamber 15.Term controller used herein is not limited only to be called in the prior art those integrated circuit of controller, and referring to integrated circuit and other programmable circuits of computing machine, processor, microcontroller, microcomputer, programmable logic controller (PLC), application-specific widely, these terms are used interchangeably in this article.Actuator 22 is connected on the preconcentrator 19.Preconcentrator 19 receives the human convection plume that comprises from the particle of human body.The particle of its reception is adsorbed or absorbed to preconcentrator 19.Controller 18 for example judges according to the variation of electromagnetic field in the passage 14 whether the people is positioned at passage 14, and when definite people was positioned at passage 14, controller 18 sent controller output signal with driving actuator 22.Actuator 22 receives controller output signal and drives preconcentrator 19 so that preconcentrator 19 moves in the desorption device 24.Desorption device 24 produces the heat of supplying with preconcentrator 19 via plurality of heating elements.When the heat that receives from desorption device 24, the particle evaporation of preconcentrator 19 absorption.Detector 20 receives the particle that steams from desorption device via pipe 26.Whether detector 20 particle detections belong to illegal material, for example arcotic or explosive substance.When the people walked out passage 14, controller 18 sent signal to actuator 22, and actuator 22 withdraws from preconcentrator 19 from desorption device 24.Preconcentrator 19 retreats to the outside of desorption device from desorption device 24.

Fig. 2 is the isometric drawing of the embodiment of preconcentrator 19.More specifically, preconcentrator 19 comprises the metal framework 28 of setting-in metallic sieve or filter screen 30.Framework 28 is made by metal material (such as but not limited to aluminium, steel and iron).In addition, filter screen 30 is made by metal material (such as but not limited to aluminium, steel and iron).Although exemplary embodiment is described as framework 28 to be made by metal material, should be understood that framework 28 can be made by any materials with high thermal conductivity in other embodiments, so that detection system 10 can as described hereinly play a role.Framework 28 comprises four

edges

32,34,36 and 38, and forms opening 40 between

limit

32,34,36 and 38.Limit 32 is adjacent with limit 34, and limit 34 is adjacent with limit 36, and limit 36 is adjacent with limit 38, and limit 38 is adjacent with limit 32.Opening 40 is adjacent with

limit

32,34,36 and 38.Framework 28 is of similar shape with filter screen 30.In alternate embodiment, the limit of framework 28 is greater or less than four.For example, framework 28 has three limits.Again for example, framework 28 has five limits.In another alternate embodiment, the limit of filter screen 30 is greater or less than four.For example, filter screen 30 has three limits.Again for example, filter screen 30 has six limits.In another alternate embodiment, framework 28 has other shape, for example square, triangle, hexagon or octagon.In another alternate embodiment, filter screen 30 has other shape, for example square, triangle, hexagon or octagon.

Fig. 3 is the isometric drawing of the embodiment of preconcentrator 19.Place filter screen 30, so that the limit 42 of filter screen 30 is adjacent with limit 32, the limit 44 of filter screen 30 is adjacent with limit 34, and the limit 46 of filter screen 30 is adjacent with limit 36, and the limit 48 of filter screen 30 is adjacent with limit 38.Each bar limit of bending framework 28 is to form a plurality of parts of framework 28.For example, bending edge 32 is to be divided into limit 32 part 52 and part 54.Again for example, bending edge 34 is to be divided into limit 34 part 56 and part 58.Again for example, bending edge 36 is to be divided into limit 36 part 60 and part 62.Again for example, bending edge 38 is to be divided into limit 38 part 64 and part 66.

Fig. 4 is the isometric drawing of the embodiment of preconcentrator 19.

Bending edge

32,34,36 and 38 is to be assemblied in filter screen 30 in the framework 28.For example, bending edge 32 is so that part 52 is pressed close to the end face 70 of filter screen 30 and the bottom surface that part 56 is pressed close to filter screen 30.Again for example, bending edge 34 is so that part 56 is pressed close to the end face 70 of filter screen 30 and the bottom surface that part 58 is pressed close to filter screen 30.Again for example, bending edge 36 is so that part 60 is pressed close to the end face 70 of filter screen 30 and the bottom surface that part 62 is pressed close to filter screen 30.Again for example, bending edge 38 is so that part 64 is pressed close to the end face 70 of filter screen 30 and the bottom surface that part 66 is pressed close to filter screen 30.Fig. 5 shows the top view of the embodiment of preconcentrator 19, and Fig. 6 shows the side view of preconcentrator 19.When placing desorption device 24 in filter screen 30 is installed in framework 28 and with preconcentrator 19, heat flows to framework 28 from desorption device 24.Heat from framework 28 flows to filter screen 30.

Fig. 7 is the synoptic diagram of the embodiment of filter screen 30.Filter screen 30 comprises that for example make by aluminium, steel or iron by heat-conducting metal for described conductive medium by a plurality of conductive mediums screen cloth of forming of

conductive medium

82,84,86,88,90 and 92 for example.The example of conductive medium comprises metal wire.Filter screen 30 comprises a plurality of openings that are formed between its a plurality of conductive mediums, and for example opening 94,96 and 98.Should be understood that also and can regard filter screen 30 as filtrator.For example, opening 98 is formed between

conductive medium

82,84,86 and 88.The example of the opening shape of filter screen 30 comprises square, rectangle, triangle or hexagon.When particle passed through filter screen 30, particle adhered to or is adsorbed on the conductive medium of filter screen 30.Each opening of design filter screen 30 so that conductive medium will in its a plurality of dimensions, have full-size for example particle of maximum length attract in around openings.For example, maximum sized scope comprise from about 1 micron to about 100 microns scope (comprising endpoints thereof).Again for example, full-size is about 20 microns.A conductive medium of filter screen 30 has identical thickness with another conductive medium of filter screen 30.In alternate embodiment, a conductive medium of filter screen 30 has the thickness different with at least one other conductive medium of filter screen 30.The example of conductive medium thickness comprises the diameter of the conductive medium of filter screen 30.

Should be understood that, although exemplary embodiment is described as filter screen 30 to be made by the screen cloth that a large amount of conductive mediums constitute, but in other embodiments, filter screen 30 can by any materials for example the metal fabric material make so that detection system 10 can as described hereinly play a role.

Fig. 8 is the top view of the embodiment of preconcentrator 19.Filter screen 30 is sintered into even, stepless pore structure.Human convection plume is towards preconcentrator 19 any identical results of mobile generation on one side.When inserting preconcentrator 19 in the desorption devices 24, the heat of desorption device 24 is 32,34,36 and 38 centers that flow to preconcentrator 19 from the limit.Filter screen 30 can be installed along any direction, for example, deviates from the direction on the ground of placing detection system 10 up along end face 70, or along the direction of end face 70 towards ground.Preconcentrator 19 is thin and lighter than typical preconcentrator.Following table 1 and 2 shows a plurality of features of preconcentrator 19 each embodiment.Although table 1 and 2 has illustrated the feature of each embodiment of preconcentrator, should be understood that in other embodiments, preconcentrator 19 can have the arbitrary characteristics that detection system of making 10 can as described hereinly play a role.

Table 1

Sequence number	Absolute filtration rating [μ m]	Bubble point pressure (1) [Pa]	Average air permeability (2) [1/dm during 200Pa ²/min]	Permeability factor K [m ²]	H/K [1/m]	Thickness H [mm]	Wt [g/m ²]	The porosity [%]	Dust ability to bear (3) [mg/cm ²]
Sequence number	Absolute filtration rating [μ m]	Bubble point pressure (1) [Pa]	Average air permeability (2) [1/dm during 200Pa ²/min]	Permeability factor K [m ²]	H/K [1/m]	Thickness H [mm]	Wt [g/m ²]	The porosity [%]	Dust ability to bear (3) [mg/cm ²]	3AL3	3	12300	9	4.80E-13	7.29E+08	0.35	975	65	6.40
5AL3	5	7600	34	1.76E-12	1.93E+08	0.34	600	78	5.47	3AL3	3	12300	9	4.80E-13	7.29E+08	0.35	975	65	6.40
5AL3	5	7600	34	1.76E-12	1.93E+08	0.34	600	78	5.47	7AL3	7	5045	57	2.35E-12	1.15E+08	0.27	600	72	6.47
10AL3	10	3700	100	4.88E-12	6.56E+07	0.32	600	77	7.56	7AL3	7	5045	57	2.35E-12	1.15E+08	0.27	600	72	6.47
10AL3	10	3700	100	4.88E-12	6.56E+07	0.32	600	77	7.56	15AL3	15	2470	175	9.87E-12	3.75E+07	0.37	600	80	7.92
20AL3	20	1850	255	1.91E-11	2.57E+07	0.49	750	81	12.44	15AL3	15	2470	175	9.87E-12	3.75E+07	0.37	600	80	7.92
20AL3	20	1850	255	1.91E-11	2.57E+07	0.49	750	81	12.44	25AL3	25	1480	320	2.98E-11	2.05E+07	0.61	1050	79	19.38
30AL3	30	1235	455	4.37E-11	1.44E+07	0.63	1050	79	23.07	25AL3	25	1480	320	2.98E-11	2.05E+07	0.61	1050	79	19.38
30AL3	30	1235	455	4.37E-11	1.44E+07	0.63	1050	79	23.07	40AL3	40	925	580	5.84E-11	1.13E+07	0.66	1200	77	25.96

60AL3	59	630	1000	1.07E-10	6.56E+06	0.70	750	87	33.97
60AL3	59	630	1000	1.07E-10	6.56E+06	0.70	750	87	33.97	5CL3	6	6100	35	4.38E-12	1.87E+08	0.82	975	85	11.67
10CL3	11	3500	95	1.07E-11	6.90E+07	0.74	900	85	17.13	5CL3	6	6100	35	4.38E-12	1.87E+08	0.82	975	85	11.67
10CL3	11	3500	95	1.07E-11	6.90E+07	0.74	900	85	17.13	15CL3	15	2400	200	2.29E-11	3.28E+07	0.75	900	85	18.95
20CL3	22	1700	325	3.67E-11	2.02E+07	0.74	900	85	29.10	15CL3	15	2400	200	2.29E-11	3.28E+07	0.75	900	85	18.95
20CL3	22	1700	325	3.67E-11	2.02E+07	0.74	900	85	29.10	5CL4	5	7400	27	1.65E-12	2.43E+08	0.40	900	72	6.80
7CL4	7	5286	45	2.74E-12	1.46E+08	0.40	900	72	9.50	5CL4	5	7400	27	1.65E-12	2.43E+08	0.40	900	72	6.80
7CL4	7	5286	45	2.74E-12	1.46E+08	0.40	900	72	9.50	10CL4	10	3700	71	4.33E-12	9.24E+07	0.40	900	72	9.50
15CL4	16	2400	150	9.15E-12	4.37E+07	0.40	900	72	11.90	10CL4	10	3700	71	4.33E-12	9.24E+07	0.40	900	72	9.50
15CL4	16	2400	150	9.15E-12	4.37E+07	0.40	900	72	11.90	20CL4	20	1850	200	1.22E-11	3.28E+07	0.40	900	72	12.00
10FP3	11	3500	90	3.71E-12	7.29E+07	0.27	600	72	3.50	20CL4	20	1850	200	1.22E-11	3.28E+07	0.40	900	72	12.00
10FP3	11	3500	90	3.71E-12	7.29E+07	0.27	600	72	3.50	15FP3	15	2450	135	6.18E-12	4.86E+07	0.30	600	75	7.50
20FP3	21	1800	200	8.54E-12	3.28E+07	0.28	675	70	6.00	15FP3	15	2450	135	6.18E-12	4.86E+07	0.30	600	75	7.50
20FP3	21	1800	200	8.54E-12	3.28E+07	0.28	675	70	6.00	40FP3	40	925	540	2.39E-11	1.21E+07	0.28	675	71	9.00
5BL3	5	7000	45	1.17E-12	1.46E+08	0.17	300	78	4.00	40FP3	40	925	540	2.39E-11	1.21E+07	0.28	675	71	9.00
5BL3	5	7000	45	1.17E-12	1.46E+08	0.17	300	78	4.00	10BL3	10	3700	100	2.59E-12	6.56E+07	0.17	300	78	4.63
15BL3	15	2470	175	4.54E-12	3.75E+07	0.17	300	78	4.70	10BL3	10	3700	100	2.59E-12	6.56E+07	0.17	300	78	4.63
15BL3	15	2470	175	4.54E-12	3.75E+07	0.17	300	78	4.70	20BL3	20	1850	255	6.61E-12	2.57E+07	0.17	300	78	6.10
40BL3	40	925	580	1.50E-11	1.13E+07	0.17	300	78	14.60	20BL3	20	1850	255	6.61E-12	2.57E+07	0.17	300	78	6.10
40BL3	40	925	580	1.50E-11	1.13E+07	0.17	300	78	14.60	60BL3	59	650	1100	2.43E-11	5.96E+06	0.15	300	74	21.50

Table 2

The technique effect that is used for the system and method for particle detection described herein comprises: compare 1 second～3 seconds (the comprising endpoints thereof) of time shortening that the particle of absorption in the desorption device 24 evaporation preconcentrator 19 is used with the time that desorption device 24 evaporation particles are used usually.Another technique effect comprises: make the useful area of the preconcentrator 19 that particle therefrom evaporates increase to 1.5 times～2 times (comprising endpoints thereof) of the useful area of the typical preconcentrator 19 that particle therefrom evaporates.The other technologies effect comprises with framework 28 surrounds filter screen 30 to promote to improve the evaporation of particle.

Although describe the present invention, one skilled in the art will appreciate that in the design of claim and scope and can implement the present invention with improved form at various specific embodiments.

Claims

1. A method of detecting particles during inspection, the method comprising:

establishing a security checkpoint with a detection system comprising a chamber defining a passage and having a plurality of jets;

passing the individual through the channel and enhancing a convective column containing particles from the individual by blowing air through at least one of the plurality of jets;

adsorbing the particles in a pre-concentrator comprising a filter embedded in a high thermal conductivity frame; and

evaporating particles adsorbed in said pre-concentrator; and

A detector is used to determine whether the particles are from at least one of an explosive substance and an intoxicating substance.

2. The method of claim 1, wherein the frame has at least four sides defining the opening.

3. The method of claim 2, wherein the filter is one of a plurality of conductive media and a metal fabric, and wherein the filter is placed in the opening of the frame and secured to the frame.

4. The method of claim 3, wherein at least one of the at least four sides of the frame is bent around a corresponding side of the filter.

5. The method of claim 1, wherein the step of evaporating particles from said pre-concentrator comprises:

inserting said preconcentrator into a desorber; and

The pre-concentrator is heated.

6. The method of claim 1, wherein said frame facilitates the step of evaporating said particles and increases at least one of sensitivity and throughput of said detection system.

7. A method of making a pre-concentrator for shortening desorption time, said method comprising:

forming a frame having four sides defining an opening;

positioning a filter over the opening of the frame; and

Each of the four sides of the frame is bent around a corresponding side of the filter, wherein the frame has a high thermal conductivity.

8. The method of claim 7, wherein the filter is one of a plurality of conductive media and a metal fabric.

9. The method of claim 7, wherein the preconcentrator receives a convection column.

10. A system for detecting particles, said system comprising:

chambers, multiple jets, preconcentrators, detectors and controllers;

wherein the chamber comprises a channel;

wherein the controller is configured to determine whether an individual is located in the lane; and

wherein the plurality of jets are located in the chamber, and the plurality of jets are configured such that at least one of the plurality of jets blows air towards an individual within the channel to enhance air containing particles from the individual A convective column, wherein the preconcentrator includes a filter embedded within a thermally conductive plate, wherein the filter is configured to adsorb the particles and wherein the detector is configured to determine whether the particles are explosive and narcotic substances at least one of the

11. The system of claim 10, wherein the filter is at least one of a plurality of conductive media and a metal fabric.

12. The system of claim 10, further comprising:

A desorber for heating the pre-concentrator and evaporating the particles to a detector.

13. The system of claim 10, wherein said preconcentrator is configured to receive said convective column.

14. An apparatus for detecting particles during inspection, said apparatus comprising:

A preconcentrator for reducing desorption time, wherein the preconcentrator includes a filter embedded in a thermally conductive frame.

15. The apparatus of claim 14, wherein the filter is configured to collect particles from a convective column associated with the individual.

16. The device of claim 15, wherein the particles are from at least one of an explosive substance and an anesthetic substance.

17. The apparatus of claim 14, wherein said preconcentrator is configured to be operatively connected to a desorber.

18. The method of claim 14, wherein the thermally conductive frame has at least four sides defining an opening.

19. The method of claim 18, wherein the filter is one of a plurality of conductive media and a metal fabric and wherein the filter is positioned in the opening of the frame and secured to the frame.

20. The method of claim 19, wherein at least one side of the at least four sides of the thermally conductive frame is bent around a corresponding side of the filter.