Explosion-proof enclosures with active thermal management using sintered elements.

(54) Title: EXPLOSION PROOF ACCOMMODATIONS WITH ACTIVE THERMAL CONTROL USING SINTERED ELEMENTS.

(54) Title: EXPLOSION-PROOF ENCLOSURES WITH ACTIVE THERMAL MANAGEMENT USING SINTERED ELEMENTS.

(57) Summary

The present invention relates to a housing, comprising: a housing having a cavity and a first opening in a first wall of the cavity; a first porous medium coupled to the first opening, wherein the first porous medium comprises a plurality of channels, wherein air passes through the plurality of channels between the cavity and an exterior of the housing; a first air displacement system placed inside the housing and close to the first porous medium, where the first air displacement system, together with the first porous medium, creates a differential pressure to force air through the first porous medium ; and a first tubular element coupled to the first porous medium, wherein the first porous medium cools the cavity as air passes out of the housing, and wherein the plurality of channels of the porous medium are fabricated using fusion deposition techniques and computational fluid dynamics to control a pore size and the shape of each of the plurality of channels within the porous medium, where the pore size and shape of each of the plurality of channels stop a flame and therefore contain an explosion within the housing, while providing an air flow, guided by the first displacement system of air, through the plurality of channels in the absence of the explosion within the housing.

(57) Abstract

Enclosures for use in hazardous areas inelude sintered filters for thermal management. The enclosures inelude an opening to which a filter holder housing and sintered filter are coupled. The enclosures can also inelude a second opening to which a vent or a second filter holder housing and sintered filter are coupled. The internal temperature of the enclosures can be actively managed by such a system because air within the enclosure can be displaced to and from the atmosphere through the sintered filters. Air from the atmosphere enters the enclosure via the second opening and exits the enclosure via the first opening.

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PATENT TITLE No. 356255

Headlines):

Home:

Denomination:

Classification:

Inventor (s):

COOPER TECHNOLOGIES COMPANY

600 Travis St., Suite 5600, Houston, Texas, 77002, USA

EXPLOSION PROOF ACCOMMODATIONS WITH ACTIVE THERMAL CONTROL USING SINTERED ELEMENTS.

CIP: H02K5 / 136; iA ^ C4 / 0 ©: f2 $ F &lt;/ 00,

CPC: HO2 (K5 / 136; A62C4 / OO. F28F7 / 00

JOSEPHWHAEL MANAHAN; tMARGJRAYMOND'K0ZL¿OWSKI

Number:

MX / a / 2015/001367

Mn International:

Olwieipn.1 3? Τ4 «'' ¹ W&gt; '··' ·^:&gt;¡··

- ·· · i &lt;«. · * - * \ '

Country:

US

Validity: Twenty years

Date of VóneimientM ^^ áñSbrifele2030? , - ·₇ \ Date of Eifefkedícióni'i'l doWiq ^ p ^ r2018 ¿'Λ'

The patent of reference ^ É ^ ftrga with furüSwBeié

Number:

12/4 ^ 5,807 aMer

Mt ^ O / hustnaL the pre-estfb patent tieflfcSh¡ of the Leytie la Propietbki Industrial.

In accordance with the aSbuJoMB of the Law of Pra ^ atMKf'lifcstriaL the ρ (% βφ pafenfe tledfc WiZβφηοβΐβ twenty (# $ forrogables, counted from the date of preser ^ ióhdb the solieáJdHOjtemacieiSí and ^ SMefcjaa ^ ^ 'peramanjjíler vlger ^ sf ^ detechos.

Who subscribes the present tftufertO'til ^ based on 'tisfcuel' faith^lp »rJps¹a¿q0WB 6 ° fraccionee.HI y 7 '(Ws' (Official Gazette of the Federation (B&gt; 0íR&gt; 27 / Ó6A 994 «./ eformáa eMAW4₍ ®WraS6 * «12 / 198W t 25/01/2006, 06/05 / 2009,06 / 01/2016 (T6¿p6 / 2P10,: ÍÍ8 / O6 / 2OlÍ7 | 27 / (l / 2O12 and d9 / 0A / 2O12) | art¡óulpft1⁰, 3 ° fra &amp; 4 | rt5 Regulations of the Mexican Institute da ta PtepieSad lr ^ gtBat_%(®^:Q, F. WWT099 rlfonMilytl 01 ^ 7 / ^ ¾ ^ ¾ articles 1st, 3rd, 4th, 5th section V subsection á) (rtfr43ccioiHÍS lar III Éstátutg, Xjt ^ Smco dflUn

12/27/1999, amended on 10/10/2002, 29/0 ^ 2004. β *_τιDeputy Generals, Coordinator, Departmental Directors, and other subordinates of the Institute ΜΜ3) ^) Ι 08/04/2004 and 09/13/2007). * 'deiufatS ^'^to Industrial Property 1999, 01/26/2004, 06/16/2005, a), 4th and 12th sections I and III of 004, 07/28/2004 and 09/07/2007); of Industrial Property (DOF ABuerSo that delegates powers to the Directors is, Divisional Deputy Directors, WpsWI Coordinators ^^^^ 5tí2 / 1999, amended on 02/04/2000, 07/29/2004, i A *

This letter is signed with an advanced electronic signature (FIEL), based on articles 7 BIS 2 of the Industrial Property Law; 3 of its Regulations, and 1 fraction III, 2 fraction V, 26 BIS and 26 TER of the Agreement establishing the guidelines for the use of the Electronic Payment and Services Portal (PASE) of the Mexican Institute of Industrial Property, in the procedures indicated.

DIVISIONAL DIRECTOR OF PATENTS NAHANNY CANAL REYES

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Original string:

NAHANNY MARISOL CANAL REYES | 00001000000403252793 | Tax Administration Service | 1695 || MX / 2018/42792 | MX / a / 2015/001367 | Normal patent title with PCT divisional | 1027 | RGZ | Page (s) 1 | l / 0S2hAEqFP + A4Tjllw85Ee + k1E =

Digital stamp:

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DN4P5l9F3rsTAQH6BTe6nSr0DI / h0QA443 + obM1aFnKgH8AWHwS2fqjUtS6nD9Cilí1OPp + rkpPVq1ZMU7DFtLz2X

4F7rpJ / S5ohlHxn5sFxNHojuXtYulheEwmLteYyj3CKu1 / 5 / npaHbhVD9QpFmTZN1GV5jGLw ==

Arenal No. 550. Floor 1. Santa María Tepepan Town, Xochimilco, 16020. Mexico City;

(55) 53340700 www.gob.mx/iinpi

<img file="MX356255B_D0004.tif" />

MX / 2018/42792

35G¿SS

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EXPLOSION PROOF ACCOMMODATIONS WITH CONTROL noi

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INSTITUTO MSXIC »NO

I HEARD THE FJOPltTY, INDUSTRIAL

ACTIVE THERMAL

<img file="MX356255B_D0005.tif" />

USING SINTERED ELEMENTS

Cross reference to related requests

The present application refers to US patent application 12/466, 249, entitled Explosion Proof Accommodations with Active Thermal Control by Heat Exchange and filed on May 14, 2009, under the name of Joseph Michael Manahan et al, the full description of which is incorporated herein by reference in its entirety.

Technical field of the invention

The invention relates generally to explosion proof housings and more particularly to explosion proof housings having active thermal control capabilities with sintered materials.

Background of the Invention

Automation equipment can be used to preserve the life of devices such as motors and pumps, improving device performance. However, the installation of automation equipment in hazardous or explosive environments has generally been

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ΙΝ. &lt;ΗηΡΌ ί&gt; ϊ LA ihou&gt; r ¡jal

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avoided due to the high temperature generated by the components of the automation equipment, which could cause an explosion. The requirements for hazardous areas require that this equipment must be sealed from the surrounding atmosphere to completely contain any possible source of ignition within the housing, thus preventing the spread of an explosion.

The automation equipment could potentially be housed in an explosion proof enclosure. Currently, explosion proof housings rely on conductive heat transfer to dissipate heat produced by equipment within the housings. However, these housings do not adequately dissipate the heat produced by the automation equipment inside them and this could lead to a decrease in the life of the equipment or lead to an explosion inside the housing. As a result, automation equipment is typically installed outside the limits of the hazardous area, and long electrical cables are routed to devices within the hazardous area. Several disadvantages exist in this configuration. For example, this configuration results in a lack of control on the device, as well as an increase in installation and / or maintenance costs.

Therefore, there is a need in the state of the art for automation of one explosion proof housing and another for equipment that can provide active thermal control in a hazardous area.

<img file="MX356255B_D0008.tif" />

Summary of the invention

The present invention can satisfy the need described above by providing housings that have sintered filters for use in hazardous areas. As applied herein, the term "sintered filter" refers to any sintered element with channels that allow air flow through it. Some sintered filters are thermal conductors and have the ability to remove some of the heat energy from a flame that passes through them and therefore can stop a flame that passes through them. In other words, some sintered filters can prevent the spread of flames by removing one of the elements (heat) from the combustion triangle (oxygen, fuel, and heat).

The housings of the present invention include an opening to which a sintered filter system is attached. In some respects, the housings include another opening to which a vent or any other sintered filter system is attached.

Sintered filter systems usually include a filter holder and a sintered filter placed inside. The filter supports can be cylindrical, rectangular or conical in shape. Sintered filters can be of any shape. In some respects, the sintered filters may be cylindrical, rectangular in shape, or similar in shape to an elliptical paraboloid. In some respects, the sintered filters may be

<img file="MX356255B_D0009.tif" />

screwed into the housing without the use of a. filter holder. Sintered filters can include channels that have a flame path of about one inch (2.54 cm) and a pore size of about 38.1 microns. In certain respects, the sintered filters may include channels having a pore size of about 101.6 microns.

The housings may also include at least one fan positioned proximal to one or both of the sintered filter systems. The fan can be controlled by a control system that has a sensor and a controller. In one aspect of the invention, the fan forces air out of one of the sintered filter systems. As a result, atmospheric air is introduced into the housing through the other sintered filter systems. In some respects, atmospheric air can be either cold air or hot air to improve performance based on ambient conditions. In another aspect of the invention, the fan pushes air into the housing through one of the sintered filter systems and air is expelled through the other sintered filter system.

In certain aspects of the invention, the housings may include a heating element to heat the air within the housings. The heating element can be controlled by a control system that has a sensor and a controller.

These and other aspects, objects and features of the invention will be apparent to those skilled in the art in

<img file="MX356255B_D0010.tif" />

consideration of the following detailed description of the exemplary embodiments representing the best mode for carrying out the invention as it is currently perceived.

Brief description of the drawings

Figure 1 is a front view of an explosion proof housing with the cover removed according to an example embodiment.

Figure 2 is a top perspective view of the explosion proof housing shown in Figure 1 according to an example embodiment.

Figure 3 is a bottom perspective view of the explosion proof housing shown in Figure 1 according to an example embodiment.

Figure 4 is a cross sectional view of the explosion proof housing shown in Figure 1 according to an example embodiment.

Figure 5 is a cross-sectional view of a sintered filter that can be used in combination with the explosion-proof housing shown in Figure 1 in accordance with an example embodiment.

Figure 6 is a cross sectional view of a sintered filter that can be used in combination with the explosion proof housing shown in the "• rr -rw ftah τ *;&gt;,

Τ? · '&gt; ·. JL ι.'ϊ¡-. ). 'one .

wr. ~ /. v; ·. · / RA

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&gt; 3. .vx. '• -i. J.Í - ** ·¹Figure 1 according to an alternative embodiment in example.

Fig. 7 is a sectional view of an explosion proof housing according to an example alternative embodiment.

Detailed description of modality examples

The application describes housings that have active thermal control capabilities. The housings include a sintered material that provides a breather to the atmosphere. The accommodations can be used both for general purposes and in dangerous areas.

The present invention can be better understood by reading the following description of the non-limiting modalities with reference to the attached drawings where similar parts of each of the figures are identified by the same reference numbers.

Figures 1 to 3 correspond to the front, top and bottom perspective views of an explosion proof housing (100) with a cover (not shown) removed according to an example embodiment. The housing (100) includes a rectangular housing (102). The housing (102) includes an upper wall (102a), a lower wall (102b), two side walls (102c), a wall and a cavity (102e), a flange (102f)

The rear casing (102) (102d) also includes extending orthogonally from the top, bottom and two walls.

IMPí^r~

MEXICAN INSTITUTE.

OF THE RROPIEOAI. \

INDUSTRIAL * «« ... 'lateral (102a), (102b), (102c). In certain embodiments, the enclosure 102 is made of aluminum and is a NEMA 7 compliant enclosure for indoor or outdoor use in hazardous locations classified as Class I, Groups A, B, C, or D.

Housing (100) also includes automation equipment (110) positioned within cavity (102e) and coupled to rear wall (102d). In alternative embodiments, the automation equipment 110 can be attached to the top wall 102a, bottom wall 102b, or one of the side walls 102c. Automation equipment (110) produces heat within housing (100), which must be dissipated to maintain a desired temperature within housing (100). In certain embodiments, automation equipment 110 may include a controller, such as a variable frequency drive (VFD) that controls the frequency of electrical power supplied to an external device, such as a pump or a motor (not illustrated). In certain embodiments, automation equipment 110 may also include a transformer, a programmable logic controller (PLC), and / or a line reactor.

Housing (100) also includes a filter holder (120), along with housing (102). The filter holder (120) can be coupled to the housing (102) by any suitable means that can maintain the integrity of the hazard classification of the housing (100), for example, by means of threads or by means of bolts in a tab (no

<img file="MX356255B_D0011.tif" />

illustrated) in the filter holder (120) of the housing (102). The filter holder (120) has a sintered filter (150). In certain embodiments, the filter holder 120 and the sintered filter 150 are two separate pieces. In certain embodiments, the sintered filter (150) is sealed within the filter holder (120). In certain alternative embodiments, the filter holder (120) and the filter

<td>sintered</td><td> (150</td><td>) are integrated into</td><td>a</td><td>only</td><td>system of</td><td>filter</td>

<td>sintered.</td><td>The</td><td colspan="2">filter holder</td><td> (120)</td><td>extends</td><td>toward</td>

<td>out from</td><td>the</td><td>bottom wall</td><td colspan="2">(102b) and</td><td colspan="2">has an area of</td>

variable cross section from one end adjacent housing 102 to an opposite end. For example, the filter holder 120 can be conical, as shown in Figures 1, 3, and 4. In certain alternative embodiments, the filter holder 120 has a constant cross-sectional area. The size and shape of the filter holder 120 and filter 150 can be configured based on the amount of air flow desired.

The housing (100) further includes another filter holder (130) coupled to the housing (102). The filter holder (130) can be coupled to the housing (102) by any suitable means that can maintain the integrity of the hazard classification of the housing (100), for example, by means of threads or by means of bolts in a tab (not shown) on filter holder (130) to housing (102). The filter holder (130) houses a sintered filter (160). In certain embodiments, the filter holder 130 and the sintered filter 160 are two separate pieces. In certain modes, the sintered filter

I

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w »nrjTc I-'f Í.A

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(160) is sealed inside the filter holder

<img file="MX356255B_D0014.tif" />

Certain alternative embodiments, the filter holder (130) and the sintered filter (160) are integrated into a single sintered filter system. Filter holder 130 extends outwardly from top wall 102a and has a constant cross-sectional area. In certain embodiments, the filter holder 130 is cylindrical in shape, as shown in Figures 1, 2, and 4. In certain alternative embodiments, the filter holder (130) has a variable cutting area from an end adjacent the housing (102) to an opposite end. The size and shape of the filter holder 130 and filter 160 can be configured based on the amount of air flow desired.

Fig. 4 is a cross sectional view of the explosion proof housing (100) according to an example embodiment. Filter holder 120 includes a sintered filter 150 placed therein and filter holder 130 includes a sintered filter 160 placed therein. Sintered filters 150, 160 can be sealed within filter holders 120, 130 to maintain the integrity of the hazard rating of housing 100. Sintered filters 150, 160 for example are substantially similar in shape to an elliptical paraboloid. The sintered filters 150, 160 have a thickness that is substantially uniform. In certain embodiments, the sintered filters 150, 160 have a thickness of approximately one inch (2.54 cm). The thickness of the sintered filters 150, 160 can vary as long as the path length of the openings, oi 2 · 4 tx.Zí:, -.-. . . . O (which are described in detail with is approximately one inch (130) also includes a fan channels, inside with respect to Figure 6) (2.54 cm).

The filter holder (420) placed inside the casing (102) and next to the sintered filter (160). The fan (420) can be powered by an internal power source, such as a battery (not shown), or receive power from a source (not shown) external to the housing (100). The fan (420) forces hot air from inside the housing (102) through the sintered filter (160) into the atmosphere. The movement of air from the housing (100) to the atmosphere by the fan (420) also forces cold air from the atmosphere into the housing (102) through the sintered filter (150). The cold air from the atmosphere enters the housing (102), is heated by the heat produced by the automation equipment (110) and leaves through the sintered filter (160).

In some alternative embodiments, the fan (420) may be positioned proximate the sintered filter (150) and force cold air into the housing (102) from the atmosphere and thus result in a displacement of the hot air through the filter. sintered (160). In another embodiment, the fan (420) may be close to the sintered filter (160), while a second fan (not shown) may be included and close to the sintered filter (150). In another embodiment, the fan (420) can be located outside the casing (102) in any η-1-η if ·! Γ on both sides of filters 150, 160 In another embodiment, fan 420 may not be present. The hot air inside the housing (100) rises and comes out through the filter (160), therefore draws the cold air from the atmosphere into the housing (100) through the filter (150). A person skilled in the art will recognize that any number of configurations having a fan are possible.

In including some modalities, the housing (100) can a control system (450) for monitoring and

<td>control of a</td><td>element</td><td>of</td><td>cooling,</td><td>such</td><td>how</td><td>the</td>

<td>fan (420)</td><td colspan="2">. In modalities</td><td>alternatives,</td><td>the</td><td>system</td><td>of</td>

<td>control (450)</td><td>monitors</td><td>and</td><td>controls a</td><td colspan="2">element</td><td>of</td>

heating. The control system (450) generally includes a sensor (not shown) that is coupled to a controller (not shown) that controls the heating or cooling element. The sensor actively or passively monitors the conditions inside the housing (100). Based on the conditions within the housing (100), the controller can turn the heating or cooling element on or off. For example, the sensor may be a temperature gauge that senses the temperature within the housing (100). When the sensor indicates that the temperature inside the housing (100) is too high, the controller turns on the fan (420). Similarly, when the sensor indicates that the temperature inside the housing (100) is low, the controller can turn on a heating element to heat the air inside the housing (100). In some modalities, the

ΪΜ control (450) can toggle between on ... and. ™ ^ p.sq.ado ^ _ passively. For example, the control system (450) can cycle such that the heating or cooling element is active for ten minutes every half hour. In certain embodiments, the control system (450) includes a sensor capable of detecting changes in humidity within the housing (100). If the sensor detects that the relative humidity inside the housing (100) is too high, the control system (450) can turn on the fan (420) to facilitate the movement of air from inside the housing (100) to the outside of the accommodation (100). In certain embodiments, the control system 450 includes a sensor capable of determining whether an explosion has occurred by detecting a rapid change in temperature or pressure. Upon detection of an internal explosion, the sensor communicates the state change to the controller that communicates the state change from a local indicator (not shown) or wirelessly to a remote location. A person skilled in the art will recognize that the control system (450) can be programmed in any number of ways to satisfy the specifications of a given area and include any number and type of sensors to determine the different states within the housing (100). In certain embodiments, the control system 450 is wirelessly controlled by a user at a remote location.

Fig. 5 is a sectional view of a sintered filter 500 which can be used as the sintered filters 150, 160 according to an embodiment in

Λ ... JS ..- *, * - ··

<img file="MX356255B_D0015.tif" />

<img file="MX356255B_D0016.tif" />

example. The sintered filter 500 has a substantially parabolic cross section. The sintered filter 500 includes substantially linear channels 510 extending therethrough. The channels (510) have a length of about one inch (2.54 cm) and a pore size of about 38.1 microns. In certain alternative embodiments, channels 510 have a pore size of approximately 101.6 microns. The sintered filter (500) has an IT thickness of about one inch (2.54 cm). In certain embodiments, the sintered filters 500 can withstand at least 560 pounds per square inch (psi) (3,861.06 kPa), without fracturing or distorting.

Fig. 6 is a sectional view of a sintered filter 600 that can be used as the sintered filters 150, 160 according to an example embodiment. The sintered filter 600 has a substantially parabolic cross section. The sintered filter 600 includes random channels 610 extending therethrough. Each channel (610) has a length of about one inch (2.54 cm) and a pore size of about 38.1 microns. As such, the sintered filter (600) has a thickness T2 that may be less than one inch (2.54 cm). In certain alternative embodiments, each channel (610) has a pore size of about 101.6 microns. In certain embodiments, the sintered filter (600) can withstand at least 560 pounds per square inch (psi) (3,861.06 kPa), without fracturing or distorting.

<img file="MX356255B_D0017.tif" />

<img file="MX356255B_D0018.tif" />

í Κύ ^ υ'.ύ'νί

In alternative embodiments, the aiabex filters..b ^ .. the present invention may have channels that follow a curved, parabolic, helical, or other suitable path. In general, the sintered filters of the present invention are designed based on the control of the size and geometry of the free volumes within the sintered filters, in other words, controlling the pore size and relating this pore size to the length of the channels. The sintered filters of the present invention can be of any shape. The shape determines the amount of air flow through them and directly correlates it with the cooling performance of the sintered filters. A person skilled in the art and with the benefit of this description will recognize that the sintered filters of the present invention can include a number of channels with different configurations to satisfy the requirements of hazardous locations.

The sintered filters 500, 600 can be made from any material that can withstand the dynamic effects of explosions without distortion or permanent damage. Some suitable examples of sintered materials include, but are not limited to, ceramic, copper, glass, aluminum, stainless steel, alloys of other metals such as austenitic nickel-based superalloys, reactive materials such as titanium, and thermally conductive polymers. Sintered filters 500, 600 are designed to allow air flow through them. In certain embodiments, the sintered filters 500, 600 are made of a

<img file="MX356255B_D0019.tif" />

írwvíT.

<img file="MX356255B_D0020.tif" />

thermally conductive material and have a sufficient channel configuration (eg, length, diameter) to stop a flame to contain any explosion within the housing (102).

In an exemplary embodiment, the sintered filters 500, 600 can be produced using rapid prototyping and more particularly, rapid manufacturing. As used herein, the terms rapid prototyping and rapid manufacturing refer to any technique related to automated construction of physical objects using solid freeform fabrication. A specific time frame for manufacturing is not implicit in the terms. Suitable methods for the manufacture of the sintering filters 500, 600 for example include, but are not limited to, laser engineered (trademark) network forming (LENS). Net Shaping), or laser fusion, developed by the National Sandia Laboratories and Selective Laser Sintering (Registered Trademark) (SLS), developed by 3D Systems, Inc. Fusion deposition techniques, in combination with computational fluid dynamics, can allow the precise deposition of materials to create a sintered filter in such a way that the creation of channels within the sintered filter can be controlled. The size and shape of these channels can be controlled as desired to produce a desired pore size and length for each flame path to adequately suppress the flame while providing the flow of

<img file="MX356255B_D0021.tif" />

desired air through it.

The sintered filters of the present invention can also be produced by pressing sintered materials, such as small bronze balls about 200 microns in diameter or stainless steel lamellae, into a mold to form a substantially circular, square or rectangular component. The component is heated to a temperature below the actual melting point of the material, but at a temperature high enough to allow the sintering particles to fuse. The sintering particles fuse in the areas where they are in contact with each other. Finally, the fused sintering particles form a matrix of channels within the component, thereby forming a sintered element.

FIG. 7 is a cross sectional view of an explosion proof housing (700) according to an alternative embodiment example. Housing 700 differs from housing 100 in that housing 700 uses cylindrical sintered filters 750, 760 instead of filters 150, 160 and are intended for prevent water from entering the housing (700). The housing (700) includes a housing (702) similar to the housing (102) of the housing (100). The casing 702 includes an upper wall 702a, a lower wall 702b, two side walls 702c, and a rear wall 702d. Housing (700) also includes automation equipment (110) positioned within housing (702) and coupled to rear wall (702d).

<img file="MX356255B_D0022.tif" />

injetPE ί, Λ

The housing (700) includes a cié fi 1 tro support (720), coupled to the housing (702). Filter holder 720 may be attached to housing 702 by any suitable means to maintain a seal. The filter holder (720) has a sintered filter (750), which is described below. Filter holder 720 extends outwardly from bottom wall 702b and has a constant cross section. In certain embodiments, the filter holder 720 is cylindrical in shape, as shown. In certain alternative embodiments, the filter holder 720 has a variable cross section.

Housing (700) further includes another filter holder (730), coupled to housing (702). The filter holder (730) can be attached to the casing (702) by any suitable means that can maintain the integrity of the hazard classification of the housing (100). The filter holder (730) has a sintered filter (760), which is described below. Filter holder 730 extends outwardly from top wall 702a and has a constant cross-sectional area. In certain embodiments, the filter holder (730) is cylindrical in shape, as shown in Figure 7. In certain alternative embodiments, the filter holder (730) has a variable cross-sectional area from one end adjacent to the housing ( 700) to an opposite extreme.

The sintered filters 750, 760 are substantially cylindrical in shape. The sintered filters 750, 760 have a thickness that is substantially

<img file="MX356255B_D0023.tif" />

uniform. In certain modalities, the filters ... sinterized s (750), (760) have a thickness of approximately one inch (2.54 cm). In certain embodiments, the thickness of the sintered filters 750, 760 is based on the desired flame arresting properties. The thickness of the sintered filters 750, 760 can vary as long as the path length of the openings within is sufficient to dissipate the desired amount of heat. In certain embodiments, the path length of the openings within is approximately one inch (2.54 cm).

The filter holder (730) also includes a fan (420) close to the sintered filter (160) and placed on the outside of the casing (702). The fan (420) draws the hot air from inside the casing (702) through the sintered filter (750) into the atmosphere. The movement of air from the housing (700) to the atmosphere by the fan (420) also draws cold air from the atmosphere into the housing (702) through the sintered filter (760).

In some alternative embodiments, the fan (420) can be placed close to the sintered filter (760) and forces cold air into the casing (702) from the atmosphere and thus lead to a displacement of hot air through the filter. sintered (750). In another embodiment, the fan (420) may be close to the sintered filter (760), while a second fan (not shown) may be included and close to the sintered filter (750). In another embodiment, the fan (420) can be placed within

<img file="MX356255B_D0024.tif" />

<img file="MX356255B_D0025.tif" />

MEXICAN INSTITUTE OF THE RR.WF.DAD

INDUSTRIAL housing (702) on both sides of filters (750), _ (760). In another embodiment, the fan 420 may not be present. The hot air inside the housing (700) rises and comes out through the filter (760), therefore it draws the cold air from the atmosphere into the housing (700) through the filter (750). A person skilled in the art will recognize that any number of configurations having a fan is possible.

In some embodiments, housing (700) includes a cylindrical tube (770), coupled to filter bracket (730), and is a NEMA 3, 4, or 9-compliant housing. Tube (770) includes a double (770b). which helps prevent water from entering the housing (700). The housing also includes a cylindrical tube (780), coupled to the filter holder (720).

In certain alternative embodiments, tube 770, 780 can be coupled directly to sintered filters 760, 750, respectively. Tube 770, 780 provides tubing for housing 700. In certain embodiments, for example, tube 770, 780 are constructed from plastics, rubber, metals such as aluminum, brass, and stainless steel, corrosion resistant materials, or chrome or painted material.

Therefore, the present invention is well suited to achieve the aforementioned purposes and advantages, as well as those inherent therein. The particular exemplary embodiments described above are illustrative only, as the present invention may be modified and may be practiced in different ways but

<img file="MX356255B_D0026.tif" />

equivalents for a person skilled in the art and with the benefit of the present description. Having described some exemplary embodiments of the present invention, the use of alternative sintered filter configurations having channels related to pore length and size are within the scope of those in the art. Additionally, while the present application describes elliptical, paraboloid, and cylindrical sintered filters, it is understood that a number of other geometric configurations, such as rectangular, can be used based on the desired air displacement properties and the use of the teachings described here. Furthermore, the exemplary embodiments of the present invention can be used to actively displace cold air from inside the housings into the atmosphere. Furthermore, while the present application discusses the inclusion of two sintered filters in one housing, it is understood that the housings may include a single sintered filter or multiple sintered filters. In embodiments where a single sintered filter is included, a vent, or a drain, may be included to displace condensation that accumulates within the housing. While many changes to the invention may be made by a person skilled in the art, such changes are within the spirit of this invention as defined in the appended claims. Furthermore, the construction or design details shown in this document do not limit the invention, other than as described in the claims below. Therefore, it is evident that the particular modalities for example described

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previously they can be altered or modified .., and_ „T-pdas ·. These variations are considered within the scope and spirit of the present invention. The terms in the claims have their ordinary, ordinary meaning, unless explicitly and clearly defined by the patent owner.

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