US2151180A - Conservation venting device and flame arrester - Google Patents

Description

March 21, 1939. R NS MM 2,151,180

' CONSERVATION VENTING DEVICE AND FLAME ARRESTER Filed Jan. 31, 1936 2 Sheets-Sheet 1 17 106721 0? ZPucZov/a J (Yrzac/zzicka.

March 21, 1939. R. J. ANSCHICKS CONSERVATION VENTING DEVICE AND FLAME ARRESTER Filed Jan. 31, 1936 2 Sheets-Sheet 2 IN I H fizz/677.307 ffuofo zzz/z J Quack z'cs Patented Mar. 21, 1939 CONSERVATION VENTING DEVICE AND FLAME ARRESTER Rudolph J. Anschicks, Chicago, 111., assignor to Protcctoseal Company of America, Chicago, Ill., a corporation of Illinois Application January 31, 1936, Serial No. 61,719

Claims. (Cl. 220-88) My invention relates to venting devices and more particularly it relates to closure devices for the vent openings of storage tanks containing oil, gas or other volatile substances, such devices parts herein shown and described and more particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like or corresponding parts:

5 being automatically operable to open both to Fig. 1 is an elevational view partly in section '5 permit the escape of vapors when the interior of a flame-proof venting device embodying the pressure exceeds a selected amount and to perprinciple of the invention; mit the ingress of air when the interior pressure Fig. 2 is a view along line 2-2 of Fig. l;

7 falls below atmospheric pressure, the device oth- Fig. 3 is an end elevational view of the device erwise remaining closed, thereby conserving the with a portion of certain members shown as par- 10 vapor by minimizing the flow from the tank. tially removed;

Under occasional atmospheric conditions there Fig. 4 is a view along the line 4-4 of Fig. 3; is a tendency for the escaping vapors to satu- Fig. 5 is a view of one of a plurality of plates rate the atmosphere surrounding the tank to the assembled to form a flame arrester; and

point of inflammability and in the event of ig- Fig. 6 is a s ti na w of a flame arrester 15 nition when the vent is open, flame arresters formin a p r n of th d vi and lustratin must be provided if the resulting combustion is a Screen forming anauXiliary ba fl to be prevented from traveling either slowly or Testerexplosively into the tank. Ignition of the es- Referring P more particularly to the draw aping apors having ccurred frequently ings, the devlce is shown as including a Valve 20 happens that they burn continuously on the housing providing a chamber H open at one emergent face of the flame arrester so long as F The P i of the housing is preferably the Venting device is open to permit their c rcular and interiorly threaded to provide a fluid cape from the tank. Under some conditions, the F 29 pipe combustion adjacent the arrester produces a blue 15 h m vertmal. posmon i 15 adapted to flame of high temperature tending to heat the provide a vent opening for an oil or gas storage arrester either to the point of melting or to a tank not shown and through .whlch mflammable temperature sufiicient to ignite the inside vapors. 2 :3 5: 55 the tank Into the surround It is an object of the invention to provide Tb; intlrmitfent miss. f d 1 n an improved venting device including flame arfl e 0 yapors an nux of air through the vent openmg due to varyresters adapted to permit prolonged burning or vapors on-the emergent face of the arrester and mg tank pressure 18 m common parlance known H as breathing. The vapors so emitted by a to so control the condition zone that 1t 1s prebreathing tank are m i t to entail a Vented from reachmg the Vent Openmg m the stantial loss if their escape is unretarded, and in 35 tankorder that the vapor loss be minimized, the chamsio r l gg ir l i l il-lgfgvgg g alfgg zg fig nf zr z gg; her I I is closed to the atmosphere by valve mechanism adapted to open when the pressure in the devi e adapted to p l gases fiOW freely tank exceeds atmospheric pressure by an amount 40 there a the1T combustlojfl 0n the whichthe tank structure can safely resist. A 4.0 emergent race to 00CLlI' WlthOLlt hcat ng t cconduit l3, extending through the chamber I l lce t the meltlng. P011113 1175 Inner faces to and projecting laterally from opposite sides a temperature sufficlent t smt th vapors. thereof, provides ports 14 and I5, respectively vigogugzhaefl olrorigggvzfdthaeprl vgggggnvstiglrievggicontrolled by valves it and l! for the escape of vapors and the admission of air to the tank. The 4.3 mg devi 0f the kind. descrlbcd which 15 weight of the valve l6 normally maintains it in ple, easily assembled, 1nexpens1ve to manufacthe closed position of the port 14 until it is liftture, durable and satisfactory for its intended ed by the pressure of the accumulated vapors in purpose. 0 the tank and permits their escape whereby the cll/gaggle6:121e11;erzlggleiiovalndanadizgtgieasi slfmtgg Eternal] tank plressureo 1s lowered sufliciently that 50 e va ve is c osed y gravity. The described obvious to thoseskilled in the art from the disoperation of the valve l6 conserves the vapors closure herein g1ven. since the port 14 thereby remains closed for all To this end my invention consists in the novel tank pressures except those exceeding the maxiconstruction, arrangement and combination of mum determined by the weight of the valve. The 55 valve II similarly maintains the port I closed for all tank pressures above a selected minimum less than atmospheric pressure. If the tank pressure falls below such selected minimum, the valve I1 will be lifted from its seat and permit air to flow through the chamber II and into the tank, thereby relieving the vacuum conditions that might otherwise cause the tank to col lapse under atmospheric pressure.

The vapors escaping from the tank through the conduit I3 will, under certain atmospheric conditions, collect in the vicinity of the tank and saturate the atmosphere sufficiently to render it combustible and explosive. The venting device provides flame arresters mounted in the open ends of the conduit I3 adapted to prevent either explosive or slow travel of ignited, gases from the exterior into the interior of the venting device. The flame arresters each consist of a grid comprising a plurality of vertically extending plates I8, arranged side by side and in spaced relation, the spacing between the assembled plates corresponding to the amount that projections I9,

shown in Fig. 5, protrude from the plates.

The plates I8 are held in assembled grid forming relation by an inner annular member 20, an outer annular member 2I, and an intermediate annular member 22, fastened together by bolts 23 to form a frame for the plates. The grid frames are fastened to the open ends of the conduit I3 by extending the bolts 23 through outwardly projecting flanges 24 provided on the conduits and clamping the frames to .a fluid-tight fit with the flanges by means of cap nuts 25. The members 20 and 2| respectively overlap and slidingly fit the longitudinal edges of the plates I8 and the intermediate frame member 22 similarly fits the ends of the plates and the side of one marginal plate of each grid.

The plates I8 are held in contact with the projections I9 of the next adjacent plate by a bolt 26 mounted in one vertical wall of the member 22 in operative engagement with a pressure plate 21. The bolt 26 is operable to press the plates I8 together and thereby to maintain open spaces or apertures 29 between the plates corresponding in thickness to the amount the projections I9 protrude from the plates. A leaf spring 28, positioned between the member 22 and the plate 21, is also adapted to maintain the plates I8 in uniform closely spaced relation should the bolt 26 be accidentally loosened.

The bounding walls of the projecting ends of the conduit I3 are divergent outwardly preferably in an amount such that the total cross-sectional area of the exposed portions of the spaces 29 between the plates IB is equivalent to the cross-sectional area of the most constricted portion of the conduit, so that the flow of gases outwardly or the flow of air inwardly is not retarded by the grid. The width of the plates I8 also bears such a relation to the thickness of the spacings 29 between the plates that flames or sparks are quenched by contact with the sides of the plates before traverse of the spaces is completed.

The grid plates I8 are preferably constructed of material having non-corrosive and high heat radiating properties such, for example, as aluminum. The grids are inclined to the vertical as shown, whereby the outer face of each plate I8 has its bottom portion projecting beyond its top portion. The gases emerge from the grid in narrow laterally spaced zones corresponding to the spaces 29. The described inclination of the grid and the arrangement of the plates I8 in vertical rather than horizontal position, permits the escaping gases to ascend and burn freely with a minimum tendency to heat the grid.

The grid is protected from the elements by a hood or shield 30 positioned adjacent to and spaced from its outer face in .a manner to provide a combustion space 3I closed at the top and sides and open at the bottom for egress and ingress of air and vapors. The hood 30 is fastened to the grid frame in any suitable manner by material fusible at relatively low temperatures, the fusible material preferably taking the form of pins or counter-sunk rivets 32. continued combustion in the space 3| at excessive temperatures for a period tending to overheat the plates I8, the pins 32 will melt and permit the hood 3!] to fall oif before the plates I8 are heated to the melting point or to a temperature wherein the outflowing vapors will be ignited by contact with the inner face of the grid. The melting temperature of aluminum grid plates is approximately 1200 F. The pins 32 are preferably constructed of an alloy of lead having a melting temperature of 300 F. or less.

If the oil has a perceptible salt or caustic material ingredient suificient to corrode plates formed of aluminum or other high heat radiating materials, it is preferable that the grid plates be constructed of stainless steel or similar noncorrosive materials. Since stainless steel andlike materials have low heat radiating properties, prolonged combustion at the emergent faces of grids comprising such materials may result in the inner ends of the grid plates being heated to the ignition temperature of gases contacting therewith. In order that combustion resulting from such ignition at the inner surface of the grid may be limited to the immediate vicinity of the grid, I'have provided an auxiliary or secondary flame arrester or baffle 33 positioned in closely spaced relation and preferably parallel to the inner face of the grid, as shown in Fig. 6. The baflle 33 may comprise a single screen of approximately forty mesh or two screens of approximately thirty mesh, spaced from one-fourth to one-eighth of an inch from the grid. Should the vapors be ignited by contact with an overheated grid, the combustion will be limited to the immediate vicinity of the grid since the volume of the gas in the space or pocket 34 is so small that ignition occurs without sufficient explosive pressure to reach or penetrate the screens. The suggested spacing of the baffle 33 from the grid prevents the screen from being heated to the ignition point of gases and permits the free flow of gases to the grid,

It also happens upon occasion that burning gases will be carried by high winds underneath the conduit and into contact with the valve housing I0. Baffle plates 35, fastened to and projecting below each grid, provide barriers preventing such burning gases from reaching the exterior of the valve housing.

Thus it will be seen that I have provided an improved vapor conservation vent and flame arresting device for use with vent openings in oil or gas storage tanks or the like whereby com- In the event of bustion of vapors, disseminated by breathing of the vent opening, or that any portion of the device may become overheated.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein shown and described or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. In a Venting device, a horizontally extending conduit, a flame arrester mounted on one end of the conduit, said arrester comprising a plurality of vertically extending plates of high radiating material assembled side by side in slightly spaced relation to form a grid adapted to close the conduit to the passage of gases except through said spaces with the outer bounding ends of the plates inclined to and receding upwardly from the vertical towards the conduit, a plate member positioned outside of and in spaced relation to the grid to form a combustion chamber closed at the top and ends, said member being fastened to the conduit by means exposed to heat generated by combustion within said chamber, said means being fusible at combustion chamber temperatures below that suflicient to heat the opposite ends of the grid plates to: a point wherein gases will be ignited by contact therewith, the fusing of said means resulting in the plate dropping away from the conduit.

2. A venting device comprising a casing providing a chamber, a horizontally extending conduit providing a port opening into the chamber, a pair of flame arresting grids respectively mounted in the opposite ends of the conduit, each grid comprising a plurality of vertically extending plates of high heat radiating material so arranged side by side in slightly spaced relation as to close the conduit to the passage of gases except through the spaces, the outer edges of the plates forming each grid being inclined to and receding upwardly from the vertical towards the conduit, a pair of plate members respectively positioned outside of and in spaced relation to the grids to form combustion chambers closed at the top and ends, said members being fastened to the conduit by means exposed to heat generated by combustion with the chambers bounded thereby, said means being fusible at combustion chamber temperatures below that sufficient to heat the opposite ends of the grid plates to the ignition point of gases contacting therewith, the fusing of said means resulting in the plates dropping away from the conduit.

3. The combination with a horizontally extending gas conduit, of a pair of flame arresting grids respectively mounted in the opposite ends of the conduit, each grid comprising a plurality of vertically extending plates arrested side by side in slightly spaced relation and comprising high heat radiating material, said grids closing the conduit to the passage of gases except through said spaces, the outer ends of the plates forming each grid being bounded by faces inclined to and receding upwardly from the vertical towards the conduit, a pair of plate members respectively mounted on the conduits outside of and in spaced relation to the grids to form combustion chambers closed at the top and ends, said members being fastened to the conduits by means exposed to heat generated by combustion within said chambers, said means being fusible at combustion chamber temperatures below that sufficient to heat the inner ends of the grid plates to a point wherein gases will be ignited by contact therewith, the fusing of said means resulting in said plates dropping away from the conduit, a casing attached to the conduit and providing a chamber, said conduit providing inlet and outlet ports opening into the chamber, valve mechanism intermittently operable by pressure differentials in the casing chamber and the conduit to open and close the ports, and means for mounting the casing on a tank with the chamber connected with a vent opening in the tank.

4. The combination with a horizontally extending conduit, of a pair of flame arresting grids respectively mounted in the opposite ends of the conduit, each grid comprising a plurality of vertically extending plates arranged side by side in slightly spaced relation, said grids closing the conduit to the passage of gases except through said spaces, the outer ends of the plates forming each grid being bounded by faces inclined to and receding upwardly from the vertical towards the conduit, a pair of plate members respectively mounted on the conduit outside of and in spaced relation to the grids to form combustion chambers closed at the top and ends, said members being fastened to the conduit by means exposed to heat generated by combustion within said chambers, said means being fusible at combustion chamber temperatures below that sufficient to heat the inner ends of the plates to a point wherein gases will be ignited by contact therewith whereby the fusing of said means results in the plates dropping away from the conduit, a pair of auxiliary flame arresters each comprising a screen positioned in the conduit in close proximity to the grids, a casing attached to the conduit, said casing providing a chamber 'and said conduit providing inlet and outlet ports opening into the chamber, valve mechanism intermittently operable by pressure differentials in the casing chamber and conduit to open and close the ports, and means for mounting the casing on a tank with the chamber connected with a vent opening in the tank.

5. A flame arresting device for a gas venting and air inlet conduit of the kind described, said device comprising a closure member mounted on the open end of the conduit and providing a plurality of narrow restricted gas passages extending therethrough and respectively connecting the conduit Within the atmosphere, the discharge face of said closure member being inclined in a direction to minimize contact therewith of the discharge gases, a hood member positioned in spaced relation to and forming a cover for said discharge face, said hood member having its upper and opposite lateral edges connected with the closure member to provide a combustion chamber between said members, said hood member being fastened in position by means exposed to heat generated by combustion of gases within said chamber, said means being fusible at a combustion chamber temperature below that sufficient to heat the inner portion of the closure member to a point such that gases will be ignited by contact therewith, the construction and position of said hood member being such that it will drop away from the closure member upon fusion of said fastening means.

RUDOLPH J. ANSCHICKS.

Images