US2389225A - Canister - Google Patents

Description

1945- G. A. WIECZOREK, JR, ET AL 2 CANISTER Filed Nov. 24, 1959 2 Sheets-Shet 2 INVENTOR.

GEORGE A. W/ECZOQE/C J2. By CA 5y 8. yqogv A ORNEY.

Patented Nov. 20, 1945 CANISTER George A. Wieczorek, Jr., Pittsburgh, and Carey E. Jackson, Forest Hills, Pa.

ApplicationNove'mbertl l, 1939,'Serial No. 305,872"

6 Claims.

This inventionrelates to an improvement in canister construction for use in connection with oxygen breathing apparatus and other personal respiratory, protective devices for use in atmospheres deficient in oxygen. or contaminated with harmful substances.

It is a principal object of this invention to provide a canister construction with means to support and separate layers of filter materials there- It is a further object of this invention to provide spacing and supporting means in a canister to contain filler materials to generate oxygen for breathing and to absorb carbon dioxide in exhaled air.

A further and more specific object of this invention is to provide a supportingand spacingmeans for each layer'of material in a canister housing and which yield upon expansion of the material supported-or engaged thereby and whichv also distribute evenly air passing through the canister over the entering surface-of each of the layers of material.

In self-contained breathing apparatus comprising generally a canister connected to a breathing means attached toth face of the wearer, the canister may contain material such as the metallic peroxides, for example, sodium or potassium peroxide, which are'reactive to moisture to liberate oxygen: for breathing purpose. The physical properly orcharacteristic of this type of material is that upon: being subjected to moisture, or conditions. underwhichoxygen is liberated, the material reacts with the moisture to liberat oxygen'and also'itexpands and fuses. Unless a layer of such material is free 'to-expand', the mass fuses and bonds-together and prevents the passage of air therethrough. This condition limits materially the reactive capacity of the material, and in many instances this limit occurs within-a very short time, especially when the user is under exertion.

Accordingly, it is among the objects of this invention to-provide asupport means associated with a housing'tocontainoxygen evolving materials which means is of sucha nature'that the I ther object is to provide aninexpensive, easily assembled and adaptable support for material in .a canister.

Further objects of this inventionwill become apparent in the specification of the drawings, in which- Fig. 1 is a sectional view of a preferred embodiment of our invention.

Fig. 2 is a plan view partlyv in section taken along the line 2 -2 of Fig. 1.

Fig. 3 is a sectional view taken alongthe line 3'3 of Fig. 1.

Fig. 4 is a-plan View of a preferred embodiment o1 "a supporting element.

7 Fig. 5 is a sectional view taken along the line 5-5 of Fig. 4.

Fig. 6 is anotherembodiment of a supporting,

meansfor thechemical materials".

Fig. '7 is a plan view of the embodiment as illustrated in Fig. 6.

In Figures 1, 2 and 3the canister l is illustrated i a comprising ahousing 2 "made of thin sheet material which is formed in an oblongshape, illustrated in Fig. 2, and with its ends closedexcept for an opening 3 contained in the entering end '4 of the canister. It is .to be understood -that the illustrations and detailed description made of "a canister construction is not to beconsidered as a limitation of this invention since it is recognized that the invention has application to many types of canister construction; In this type of can ister, an opening "3 receives exhaled air'froma respiratory means, notshown; and discharges oxygen evolved within the canister; For separat ing exhaled air and air to 'be breathed; a duct5 is disposed centrally of 'th'e housing'Z and sup; ported'by end portion For the housing to receive the exhaled'airfrom' a breathingtube'not shown",

which is connected'to th duct 5 by'en'gagement' with a fitting l. 'I'he-end'of' the duct is supported in spaced relation to the end-portion B'bya'spa'cer' H: which may'be'a separable or integral part of the-duct. The entering exhaled'air passes down' through the central duct5 and is then'di'scharged in an operative space A"betweenthehousing '2 and-the tube 5," as illustrated in Fig. l. Passing. up through the operative -space -A the air 'to" be breathed is discharged from the canister through the opening 3, as illustrated.

Exhaled air passing through the operative space A passes through'a series of layers of chem= ical materialsinterposed inits pathof travel.

These materialsare reactive "with the constitu-- entsof theexhaled-air to'provide air suitable for breathing purposes, as byremoving noxious and' poisonous fluids and for generatingoxygen.- Forsupplying oxygen, his th pra'cti'ceto 'use the metallic peroxides, usually sodium or potassium" peroxide which react with moisture the 'ex-'- sary that the particles of material be sufliciently small so that air passing through a layer of the material contacts a maximum of surface of the material; but, on the other hand, they are to be large enough to provide adequate air passages for limiting as much as possible resistance to breathing.

It is to be understood that the use of the term air herein is to be construed broadly to include exhaled air and air contaminated with poisonous and noxious gases, fumes, dust, mists and vapors which may be passed through such a construction to react with or be absorbed by chemicals disposed in the path of air flow to supply respirable air.

A preferred embodiment of our invention is illustrated in Figures 4 and 5, and comprises an element IIJ made of a flat sheet of wire material of a mesh depending upon the size of particles of chemical material to be supported thereon and having sufficient flexibility to yield to the expansion of materials, such as, the oxygen evolving materials described above. The element is disposed in the operative space A flatwise across the direction of flow of air through the housing, Fig. 1. Struck from the plane of the flat sheet are shoulders II disposed adjacent the outer periphery of the sheet and shoulders I2 disposed adjacent the inner periphery defining an opening I6 for the central inlet tube 5. Each support 30, Fig. 1, is made up of a pair of such perforated elements, as I3 and I4, and the shoulders II and I2 of element I3 coact with shoulders of a like element I4, Fig. 1, and yieldable supporting surfaces I1 and I8 are provided within the shoulder portions II and I2 of element I3 and I4 respectively.

The lower end of the inlet tube 5 has outwardly projecting flanges and the inner side of the housing has a corresponding and cooperating inwardly projecting flange 2I. A base support which is illustrated as a single wire sheet, is positioned on flanges 20 and 2I and defines a space for receiving air discharged from the inlet tube 5 and before passing up through the operative space A. This space distributes uniformly the air over the entering surface of the chemical material in the initial layer in the direction of flow of air travel. Layers of material which may vary in depth depending upon the purpose of the canister and the physical and chemical properties of the filler material are supported from this base support 22.

Fig. 1 illustrates a canister containing a plurality of layers of chemical material and each layer, except the lowermost layer, is spaced from and supported by an adjacent layer of material by means of a yieldable support such as heretofore described and as illustrated in Figures 1, 4 and 5.

Fig. 1 illustrates what is thought to be the effect and function of this type of support, that is, before and during reaction, the coacting shoulders on each element provide a space between adjacent layers of' material, and during reaction, the individual elements I3 and I4 of each support 30 yield freely and allow the material, such as the metallic peroxides, supported thereby to expand in the direction of and opposite to the general direction of flow of air therethrough and thus prevent the fusion or bonding of the material which destroys the air passage through the layer. By this expansion, low resistance to air flow and substantially uniform reaction continue throughout the life of the material. It is to be observed that this support provides a yielding means for the upper or supporting surface of each layer, such as the surface engaging the element I4 of each support 30, and also the lower or supported surface, such as the surface engaging the element I3.

A further and useful function of the support is that by spacing each layer from the other, the air having passed through a lower layer is distributed evenly over the entering surface of the upper layer, and thus a uniform reaction with the material occurs throughout the layer. This function of the support is effective in eliminating channeling of air through the layers of the material, since if a channel occurs in a layer, air passing through the layer and entering the space provided between this layer and a succeeding layer is distributed uniformly over the entire entering surface of the succeeding layer. Other arrangements and means may be used for providing the yieldable and spaced supporting elements for the material to be included in a canister. For confining the uppermost layer of material, a screen 3i engaging the housing 2 and inlet tube 5 may be used.

One manner of increasing the amount of yield for one layer can be made by adding yielding elements to the support and, in some instances, an increase in yield will result if some layers of material in the canister do not expand during reaction, thus allowing the available yield at these supports for a layer which may expand beyond the yield limit of its support.

A further embodiment of our invention is illustrated in Figures 6 and 7 in which two flat screen elements 32 and 33 having the necessary porosity for supporting particles of chemical material, are supported in spaced relation by a spacer element 34, which may be of a contour such as illustrated in Fig. 4, and may be made of screen material as used for elements 32 and 33. The contour must be such as to provide the necessary yieldable surface between the supports, and so as not to interfere with the opening 36 in each screen element to accommodate the duct 5.

It is to be understood that the manner of arrangement of the supports for chemical material within the canister housing and the type of canister are not to be considered as a limitation of this invention, since it is recognized that our invention is adaptable for all types of canisters so long as the type of construction does not interfere with the action of yieldable surfaces which are provided by our support construction. It is to be further understood that no limitations are to be inferred from the detailed description of our invention and that it is to be limited only by scope of the appended claims.

We claim: a

1. In a canister having a passage therethrougn and in which layers of purifying material are disposed, a yieldable support between the layers of purifying material comprising a pair of flat strips of yieldable perforated material and a separable spacing means between the flat. strips shaped and arranged over the surfaceof each the sheet so that each of the strips is operative to yield to the expansion of the layers of purifying material engaged.

2. In a cansiter having a passage therethrough and in which purifying material is disposed in layers, a support between layers of material comprisin two sheets of perforated yieldable material, each of the sheets having a distended portion and the sheets being positioned relative to each other so that the distended portions engage each other to space the sheets from each other to render the sheets operative to yield to the expansion of purifying material,

3. In a canister including a body and a tube extending centrally of the body and defining a chamber between the body and the tube and in which layers of purifying material are placed, a support between layers of the material comprising a pair of sheets of yieldable perforated material, each sheet extending across the chamber and having an opening to accommodate the tube and a separable spacing means between the sheets of material shaped and arranged over the surface of each sheet to position the sheets in spaced relation to define an air entering space for the succeeding layer and to render each sheet operative to yield to the expansion of the engaged layers of purifyin material.

4. In a canister including a body and a tube extending centrally of the body and defining a chamber between the body and the tube in which purifying material is placed in layers a support positioned between layers of material and comprising a pair of flat strips of yieldable perforated material, each strip extending across the chamber and having an opening to accommodate the tube, each strip having portions upstruck from the plane surface of the strip and adjacent to the inner and outer peripheries of the strip, andeach strip being oppositely positioned in relation to the other so that each upstruck portion contacts itsrespective portion of the other strip to space each strip from the other and render each strip operative to yield to the expansion of the layer of purifying material engaged.

5. In a canister having a passage therethrough and in which purifying material is disposed, a support fOr the material comprising two sheets of perforated yieldable material, one of the sheets having a portion upstruck from the surface of the sheet and cooperative with. the other sheet to space the sheets from each other to render them operative to yield to the expansion of purifyin material while adequately supporting the purifying material in position.

6. In a canister having a passage therethrough in which purifying material is disposed, a support for the material comprising two strips of perforated yieldable material, each of the strips having a plurality of portions upstruck from the surface of the sheet and the strips being positioned relative to each other so that the shaped portions of each strip engage shaped portions of the other strips to space the strips from each other to render them operative to yield to the expansion of purifying material.

GEORGE A. WIECZOREK, JR. CAREY B. JACKSON.

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