US2443238A - Explosion resistant filter - Google Patents

Description

June 15, 1948.

C. J. GLANZER EXPLOSION RESISTANT FILTER Y Filed Aug. 19, Maf-ml v Fe, I

Pif-c5. 2

H il Patented June 1'5, 194s sangrar EXPLOSIN RESSTANT FILTER:

Clarence J. Glanzer, Northfield; Ohio; yassgfn'orfto' Air-Maze ..Corporation, (lleve'landf. Ohio;.a Scor porationy of vDelaware Application August 19, 1944-,3Se'rial'Nor 550;'157- many-downstream"side'thereofrto the normally upstream side. vThe' advantageous features ci my' lrnentilonareY clearly'describedin the accom# p'anyingjspecication and drawings; and the es-v sentialf'-features'are"setforth inv the appended@ claims.

Irl^ th'efdrawings,

Fig.' 1x is" af transverse' sectionall view through' one vembodiment 'of "my invention taken along. the line j'I-I of'flii'g:l 2," and Fl'gizis a: top'plan view.' 'ottonecornerk of :the device e'of 1Fig',l 1 LWith-"parts Abroken. away to 'more`` clearly'sliovvv the "construction,"

Fra'flon'g time 'there has been a' demand "xfor a ltradaptedi to remove dust and A4dirt -particle-s1 fromastream-of airor Ythe like ini ducts 'wherein explosions 'sometimes z. occur A'Witlisuch" force that anj ordinary'lter vis 'torniapartj' and ame travels along fthe normallyv ln'com'ingduct." The present invention providesY an efclent ltering `means whicli'has relativelyflow resistance to the: flow of the air "stream, which is able towithstandvery violent explosions'withoutany substantial dam# age, and which prevents' flame' propagation through-thefIter.x

While my invention may take many forms, I have chosen to illustratethelsame as embodied in a reetangulanframe i I offgeneral channel=fo1m'v section which, for purposes of easyiassembly;l is' made up of a member II of `Lfform having a longer leg IIa forming one'of 'theflat side Walls of the :trarne and having a-sh'or'ter leg IIb:'pro= vidi'n'g'afilange around one of thai-.open faces 'of theylterf` At'thevother face oftheilter, an'angle IZfh'assone 1egl2a Isecune'd to the'fleg 1' I Iaalby meansiof the ,metal screws'tl The other i legsiIZbfof this member vformsfamiange likeA `I Ibi around ,onefoffthe `faces ci'.4 theffllterf The" vframe I Il `itlieretere-loompletelyinclosesrthe fsidesfof 'the t lterdnladuot. leavingnpen front-land rear 1 faces liffandfil Dbtrespectivelyife. Forfpurpos es oi-thlse descrlptiomit is assumed Vthat the normal ylovv of` theI gaseous stream" torbeifiltered is inf the direction of thearrows `of Fig. 1T and. that .when an explosionfoccurs downstream from 'the filtering will occur in' a 'direction opposed toA those' arrows.

A `second `frame I4 'is rigidly/secured to the innerside-Walls I I a of therstframe'intermediate the'front and `rear'iaces ofthe lter'as by means of thev weldingindicatedlat I5; This Welding is continuous around theiperimeter of frame vIll-and forms `an unbroken' seal-betweenfframe I4 and frame'w'allvI Iaso thatfi'lame cannot pass along the inside offWall IIa.' It .will be noted that the frame I4 -is channel-forni` iny section having' its web Idar in heat-conductingv Contact with' the Walls zI Ia; frame I Il is constructedof sixteen-gaugesteel, Whilewthefvframe -I dis constructed ofl twenty-fourgaugeY steel. The vframe I Uli-is lledwith. eX- plosion-resistant .material which; inl thepresent instance,A comprisescaplural-ity oflayers I6 Vof brass wire twenty-fourzmeshes to the f inch in each direction. This'wre screenis provided withV gaseous-strearlrflow: It Will-be notedin Fig-..- 2; 301

layers Ia.Jr Thusthevcorrugationsof alternate layers-strengthenthev layers 'i againstv bending'V in different f directiona-andy because the` layers: are

contiguous; they; 'mutually' support 'eachv l other againstfthetforcetoi an explosion:v

Thezlayers ISYbeingamad-eof brass -have high' .heat conductivity; anrdvthefheat of `the explosive" gases isI thusA dispersed" and conducted: toward theframefl'lwhichzin turn'conducts th'e'heat-t'o' ther frameflf Much"ofitheheat-oft an explof siorr is -dissipated-=irr :this manner. Cy

upstreamfof the#explosioneresistantpanel during thenormah owicfa gaseous:stream through thefvv device:- The :'form ofiltr material fhere "shown comprises layers -ff-I 'I vande! 'ofwire:fscreeniehavin'gv v` corrugations extending nronefdiirectin; sayverti-y sayl l'iorizontall device; an abnormal' flow of'fthe gaseous:stream In thisembodiment of' mydevice, the

`closely;spacedicorrugations about ft-inches inv depth; and :there are" sixnofi these flayers shown-yk extendingfi'completely:I'across1the-frame #I 41 andf in" planes generally normal to I the direction fof' the that alternateslayers'a havcfcorrugations ex-` tendingfin one directionfvvhilerthe other layers ll'ofhave V`thecomgations extending in another; di'- rection'' soi f as r to f cross@V the: oorrugationsy of=- the Filter material is positioned in the 'framelil corrugations inch deep, the layer i9 is of 6 X 6 mesh having corrugations inch deep, and the layers I 8 and 20 are of 8 X 8 mesh having corrugations 1%; inch deep. These layers I1 to 29 are for the purpose of ltering out coarser material from the gaseous stream including any lint or material of that character. Downstream from thelayer 20 are a plurality of layers 2| (six being shown) of a finer material and preferably of bronze or similar metal. The layers 2| in this embodiment are of 16 x 16 mesh and provided` with corrugations 32 inch deep. Preferably also the layers 2| are positioned similarly to the layers i8, that is to say, alternate layers 2|@ have their corrugations extending in one direction and the other layers 2|b have the corrugations crossing the corrugations 2| a so as to prevent nesting of the layers and so that alternate layers mutually support each other.

It results from the above-described construction that in the normal use of my device, a stream of air or the like passingthrough the panel shown in Fig. 1 in the direction of the arrows has substantially all of the dust and dirt particles re' moved by means of the filtering layers TI to 2| thus maintaining the explosion resistant panel (consisting of the layers I6) free of dirt and dust. Then, when an explosion occurs, there is a minimum tendency to set the ltering device on iire because the clean screen layers I6 stop the ilame propagation, and, because they are clean, it is difficult to start a fire in the lter device. Itwill be understood by those skilled in this art that the ltering layers l1 to 2| are generally coated with oil or other viscous material so as to catch the dirt particles. Therefore, unless precautions are taken, the oil soaked dust layers on a dirtylter might easily be set on fire.

Preferably, but not necessarily, other layers of material are provided in the frame Il) downstream of the explosion resistant panel in the frame I'4. In the present embodiment, this material comprises twolayers 22 of 16 x `16 mesh bronze wire having corrugations 3/32 inch deep and positioned with the corrugations crossing each other as indicated in Fig. 2. Thenext layer 23 is of 8 x 8 wire mesh with -corrugations 3/1a inch deep, and the last twolayers 24 and 25 are of 8 x 8 wire mesh having corrugations' 3/8 inch deep. As indicated in Fig. 2, thelayers 23, 24, and '25 have their corrugations crossing to prevent nesting. Thesevlayers 22 to 25 serve to obstruct and disperse an explosive gaseous stream ahead of the layer i6 so that the explosion does not strike with full force on the'fine layers of the explosion panel. It will be noted also that thelayers 22 to 25 are not attached to therframe side walls Ila but are free to give with the ex-` plosive force of a stream travelling opposite to the arrows of Fig. 1, such resilient movement of these layers being supported by the frame I4.

Thelayers 23, 24, and 25 also 'prevent dirt in the duct downstream from the lter being carried into the layers |6 in case of anexplosion downstream.

It will be noted that al1 of the ne layers 2|, 46, and 22 are desirably made of brass or bronze which are metals of high heat conductivity. I have thus provided fourteen layers of this material in the mid-portion of the lter frame, all adapted to disperse and transfer heat from an explosive gaseous stream and to prevent ame propagation in a direction opposite to the arrows' of Fig. 1. These fourteen layers also prevent passage orame from the 'downstream side of the ,4 filter to the upstream side thereof in case of explosion downstream.

It should be noted also that I have provided a construction which will operate fairly satisfactorily even if the device is placed in the wrong position in the air duct. The normal position is indicated in Fig. 1, but, if a careless person reverses the faces Illa and lb, the" action of the device will be similar in function f although differing somewhat in degree.

What I claim is:

l. An explosion resistant filter comprising a frame adapted to beremovably mounted in a duct and having side walls and being open front and rear for the passage of a gaseous stream normally in one direction to filter particles out of the stream and abnormally in the opposite direction upon occurrence of an explosion, filtering means in said frame, a second frame inside said rst frame and an uninterrupted integral bond between said rst and secondframes rigidly `.attaching them together and preventing lay-passing of iluid between them, and a plurality of sheets of foraminous metal extending completely across said second frame in planes generally at right angles to the path of stream iiow, each of said sheets having closely spaced parallel corruga-v tions, the corrugations of some of said sheets lying at an angle to thecorrugations of otherl of said sheets, whereby said sheets are stiiened against bending in diiierent directions, and said sheets substantially touching each other whereby they are mutually supported. Y

2. An rexplosion resistant filter comprising a frame adapted to be removably mounted in av duct and having side walls andbeing open front and rear for the passage of al gaseous stream normally in one direction to lter particles out of the stream and abnormally in the opposite direction upon yoccurrence of an eXplosion,fiil,-`

tering means in sai-d frame, a second frame inside said irst frame and an uninterrupted Yintegral bond between said first and second frames. rigidly attaching them togetherand preventing by-passing of iiuid between them, and a-plurality of sheets of forarninous metal ofthe v order of wire screen having twenty-four meshes per inch each way, said sheets extending completely across said second frame in planes generally atv right angles tothe path of stream flow, each of,A I said sheets having closely spaced parallel core,

rugations of the order of three thirty-seconds inch deep, the corrugationsof some of said sheets lying at an angle to the corrugations of Yother of said sheets, whereby said sheets are stiifened against bending in different directions, and said sheets substantially touching each other ywhereby they are mutually supported.

CLARENCEv J. GLANZER..

REFERENCES crrnn The following references are yof record in the file of this patent:

. UNITED .STATES PATENTS;

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