US1960043A - Attachment for combustible gas conduits - Google Patents

Description

y 1934. R. J. ANSCHICKS ,960,043-

ATTACHMENT FOR COMBUSTIBLE GAS CONDUIT S Filed April 18, 1931 Patented May 22, 1934 UNITE STATES OFFICE ATTACHMENT FOR, COMBUSTIBLE GAS CQNDUITS Rudolph J. Anschicks, Chicago, Ill.,

Protectoseal Company of America,

assignor to Chicago, 111.,

16 Claims.

The invention relates to flame arrestor or fire baffle construction and more particularly it relates to devices adapted for mounting in vent openings, conduits or the like and in other devices for storing or conveying volatile and inflammable fluids such construction taking the form of a barrier permitting the gases or fluids to flow therethrough and at the same time extinguishing any flame or sparks resulting from the ignition of gases or fluids contained in or flowing into or out of the conduit or receptacle.

It has been observed and such observations have been confirmed by laboratory experiments that if a volume of gas is confined in a pipe or a receptacle and ignition occurs, that peculiar phenomena of sparks result. These phenomena occur following ignition of gases confined within a pipe or a receptacle having a restricted exit or vent opening relative to the volume or crosssectional area of gases contained within the pipe or receptacle. Such ignition produces an explosion following which the flame bearing gases escape through the restricted opening under pressure. The arrestor or device has a plurality of relatively narrow apertures extending therethrough and is mounted in the path of the advancing ignited gases to form a partial barrier, permitting the pressure Waves and the flame bearing gases to divide and pass through the various apertures. The flames carried by the gas are cooled, by contact with the walls bounding the apertures, to a temperature where they are extinguished before passing entirely through the arrestor.

The spark phenomena are believed to be due to the fact that the combustion of gaseous vapors under pressure is not entirely complete and that the sparks generated by the combustion are merely flne particles of flame or glowing gas molecules. The pressure and other conditions within the receptacle or conduit are such that the sparks advance at varying velocities, but at any event the velocities are much greater than the velocity of the accompanying pressure waves and burning gases. Many of the sparks strike the wall of the arrestor between the apertures and are thereby extinguished and the momentum of many of the remaining sparks which enter the apertures is such as to carry them through the apertures without being extinguished. By experiment the sparks have been found to pass through apertures having a diameter or depth as small as 9.092 of an inch. Ihe existence of such sparks, their high velocity and temperature and the fact that they pass through orifices of extremely small dimensions has been established by observations made with specially prepared apparatus in experiments in underwriters laboratories.

The minimum temperature of the glowing particles or sparks is estimated as being approximately nine hundred degrees Fahrenheit and un der proper sensitive conditions sparks of that temperature will ignite gases on the exit side of the arrestor, thereby defeating the purpose for which the arrestor is provided. The experiments have also established that the acquisition by the sparks of a velocity or momentum sufficient to carry them through the apertured arrestor requires that they be generated or propagated at some distance from the apertures of the arrestor. The provision of an arrestor having flame extinguishing apparatus of dimensions sufficiently small to shut off the sparks would so retard the flow oi the pressure waves and flame bearing gases as to make the arrestor practically useless for the purpose for which it is provided.

The invention contemplates an auxiliary attachment or shield positioned on the inlet side of and spaced slightly away from the main body or apertured portion of the arrestor. The spacing of the shield away from the main body of the arrestor is made less than the distance required for sparks to generate and attain the velocity or momentum necessary to carry them through the apertures in a glowing condition-or at a temperature sufficiently high to ignite gases collected at the exit end of the apertures.

The shield or auxiliary portion of the arrestor is so constructed that the advancing high velocity sparks will all strike the shield and be extinguished by such contact. Covered ports forming a devious path open through the shield or auxiliary member and permit the pressure waves and flame bearing gases to pass therethrough into the narrow chamber between the shield and the main member, the latter being so apertured as to permit the gas and pressure waves to pass freely and also to quench the flames. The sparks generated back of the shield strike against the walls of the shield, and such as make the turn necessary to pass through the ports have their velocity'slowed down sufficiently that they do not survive the passage through the apertures in the main body of the arrester. Such new sparks as may be generated in the narrow space between the shield and the arrestor do not acquire sufficient velocity or momentum to carry them through the flame extinguishing apertures. A shield member of the kind and in the position described, makes it impossible for live sparks to pass through the apertures provided for the escape of gases and pressure waves.

The proper functioning of flame arrestors requires an enlargement in the conduit or of the vent opening so that the arrestor may be large enough to provide apertures having a total crosssectional area equal to or greater than the crosssectional area of the most restricted portion of the conduit. The arrestor thus constructed will not perceptibly slow up the velocity of the advancing pressure waves and ignited gases. The ports through the shield member are for the same reason preferably given a total cross-sectional area substantially equivalent to that of the restricted portion of the conduit. Inasmuch as the equivalent areas of the apertures can be provided only by mounting the arrester in an expanded portion of the conduit, it is impossible to provide the conduit with a bend which will operate to stop the advancing sparks by contact with the walls of such a bend since it is impracticable even in a small conduit to make the distance from the bend to the arresting device short enough to prevent the propagation of sparks in the bend and to prevent such new sparks from attaining ,suincient momentum to carry them through the arresting device. The narrow space between the shield member and the main body of the arrestor is wide enough to permit the pressure waves and burning gases to be distributed and find an exit through all of the apertures and yet is sufficiently restricted to prevent propagation of sparks which attain the requisite velocity to carry them through the apertures.

An object of the invention is the provision of a flame arrestor for conduits and receptacles which permits flame bearing gases and pressure waves resulting from an explosion within the conduit or receptacle to quickly and readily pass through the arrestor device and which at the same time extinguishes all sparks and flames generated by such explosion.

Another object of the invention is to provide a flame and spark extinguishing device of the kind described which functions eifectively to permit the escape of gases and the distribution of pressure waves therethrough and at the same time prevents the passage of any sparks however great their velocity or small their dimensions.

A further object of the invention is to provide a device for preventing the passage of flame or sparks into or from any means for storing or conveying inflammable fluids, such device being especially rugged, simple in construction, inexpensive to manufacture, and adapted for either large or small scale installations.

A still further object is to provide a device of the kind described which can be constructed to function in the presence of pressure waves however great.

Many other objects and advantages of the con-- struction herein shown and described will be obvious to those skilled in the art from the disclosure herein given.

Referring now to the drawing forming a part of the specification which illustrate preferred embodiments of the invention:

Fig. 1 is a longitudinal sectional view through a carburetor discharge conduit equipped with one embodiment of the invention;

F Fig. 2 is a sectional view along the line 2-2 of Fig. 3 is a longitudinal sectional view through another embodiment of the invention; and

Fig. 4 is a sectional view along the line 4-4 of Fig. 3.

Referring now more particularly to the drawing, Fig. 1 illustrates a pipe 10 serving as a carburetor discharge conduit having an expanded portion 11 on which a flame arrestor is mounted. The expanded portion 11 of the pipe terminates in an outwardly projecting flange 12 providing a mounting for a frame member 13 forming a portion of the arrestor device. The member 13 is shown as having a generally Z-shaped cross-section with an inturned flange 14. The member 13 is fastened to the flange 12 by a plurality of bolts 15 so arranged as to hold the member and flange to a close fit.

The arrestor device comprises a plurality of bars or plates 16, securely fastened together by bolts 17. The plates 16 are so mounted in the frame member 13 as to close the open space within the inturned flange 14. Spacers or washers 18 are positioned between the plates 16 tol provide relatively thin apertures 24 of the width of the plates. A member 19, positioned on the inside of the flange 14, provides a gasket or washer against which the plates 16 bear and form a close fit.

A shield member, comprising a plurality of overlapping plates 20, is mounted on the inlet side of the arrestor and is fastened thereto by a plurality of bolts 23. One of the plates 20 is held in spaced apart relation from the flange member 13 by a bar 21 and the other of the overlapping plates 20 is held in overlapping spaced apart relation to the other plate 20 by means of a filler bar 22. The plates 20 are so arranged that their overlapping edges provide a covered port 25 substantially the full length of the device as observed in Fig. 1. The overlapping plates 20 are preferably so arrangcd that the port 25 formed thereby extends transversely to the longitudinal axis of the conduit. The spacing of the plates 20 is such that the port or space 25 has a cross-sectional area substantially equal to the Y cross-sectional area of the restricted portion of the conduit 10. Similarly the apertures 24 between the plates 25 are provided in suflicient number and of a depth that their total cross-sectional area is approximately equal to that of the port 25; Only two plates 20 and only one port 25 are shown, but if desirable a greater number of overlapping plates 20 can be provided to form a plurality of covered ports 25 discharging transversely into the chamber or space between the shield and the main arrestor element.

The conduit 10 is enlarged to form the expanded portion 11 in order that the arrestor ele ment may provide apertures 24 in sufiicient num ber that their total cross-section may equal or exceed that of the restricted portion of the cone duit. The pipe 10 may be a carburetor discharge pipe, or a vent opening from an oil storage tankor any other construction in which there frequently occurs a collection of volatile gases on the exit side of the arrestor. Such a collection of gases on the exit side of a vent or a carburetor exhaust opening is frequently found in the hull of gas driven launches where the conditions are favorable for a collection of inflammable gases and their ignition by the discharge of sparks through the apertures 24.

The flame bearing gases and pressure waves flowing outwardly from the conduit 10 strike the plates 20 and continue their flow through the port 25 into the space between the shield member and the main body of the arrestor. The high velocity sparks accompanying the outwardly flowing gases strike the plates 20 and are extinguished or in the event that they converge through the port 25 their velocity is so reduced as to prevent their escape through the apertures 24. The spacing of the plate 20 from the edges of the plates 16 is such that the propagation of sparks is limited and they are not permitted to attain a velocity sufiicient to emerge through the apertures 24 in a live condition. It is obvious that the device shown in Figs. 1 and 2 will prevent any escape of live sparks through the arrestor and that the construction therein shown is such as to permit the dissipation of pressure waves and also to quench flames carried by the escaping gases.

An alternative embodiment of the invention is illustrated in Figs. 3 and i as forming a part oi a flame arrestor device positioned in a pipe line made up of a plurality of sections 30. Annular members 31 and 32 each having a threaded con-- nection with one of the pipe sections 30 and outwardly turned flanges 33 fastened together by a plurality of bolts 34, form a housing for the flame arrestor. A plurality of annular plates 35, secured together in spaced apart relation by a plurality of bolts 3'7, form the main body of the device. A plurality of spacers or washers 38 positioned between the individual plates 35 result in relatively thin apertures 39 through which the volatile gases will flow in a direction depending upon the direction of flow of volatile oils or gases in the main conduit. The width of the plates 35 is such as to quench any flames being carried by the gases passing through the apertures 39. The number and depth of the apertures 39 are so determined that their total cross-sectional area is approximately equal to or slightly greater than the cross-sectional area of either of the pipe sections 30, so as to permit free flow of such and. the dissipation of pressure waves. The stack of annular plates 35 encloses a cylindrical space 40 in alignment with the main conduit. The cylindrical space 40 is of the same diameter or slightly larger than that of the pipe sections 30. A plate 38 closes the outer end of the cylindrical space 40 and compels the gases flowing in either direction to deviate and pass between the plates 35. The gases and pressure waves thus compelled to deviate are only slightly or not at all retarded thereby since the total area or" the apertures 35 is equal to or greater than the area of the sec tions 10.

The high velocity sparks, accompanying the pressure waves and ignited gases, follow a straight path which brings them into contact with the plate 38 and are extinguished thereby. The diameter of the cylindrical space 40 and the dimensions of the annular space surrounding the arrestor device are such as to permit the generation of new sparks and their acquisition of a velocity or momentum sufiicient to carry them through the apertures 39 in either direction. A shield member comprising a plurality of overlapping curved plates 41 is positioned in the cylindrical space 40 in closely spaced relation to the annular plates 35. The overlapping edges of the plates 41 provide a plurality of ports i i through which the gases and pressure waves may flow and escape through the apertures 39 when the direction of travel is from the left as observed in Fig. 3. The new sparks that may be generated in the cylindrical space 40 will strike against the concave side of the plates 41 and be extinguished. Such new sparks as may be formed in the restricted space between the overlapping plates 41 and the plates 35 cannot attain sumcient momentum to carry them through the apertures 39.

If the direction of flow of the pressure waves and ignited gases be from the right as observed in Fig. 3 the ignited gases and pressure waves will enter the space between the arrestor and the annular members 31 and 32. A shield member comprising a plurality of overlapping plates 42 are closely spaced about the outer edges of the plates 35 with their overlapping edges spaced apart to provide ports 43 through which the gases and pressure waves flow into the narrow space surrounding the plates 35 and escape through the apertures 39 in the same manner as already described for the flow from the opposite direction. The high velocity sparks accompanying the gas upon leaving the conduit section 30 strike against the plate 38 and are extinguished and such new sparks as may be formed in the annular space outside of the plates 42 are extinguished by their contact with the walls surrounding such space. New sparks generated in the restricted space between the plates 42 and the plates 35 will not gain sufficient momentum to be impelled or projected through the apertures 39. The device as shown in Figs. 3 and 4 effectively functions to prevent transmission of any flames or sparks therethrough while permitting substantially free flow of gases and the dissipation of pressure waves in either direction resulting from the ignition of such gases on either side of the arrestor.

Thus it will be seen that I have provided a combination flame arrestor and spark extinguisher which serves as a barrier to flames and sparks of all sizes and permits the dissipation of gases and pressure waves resulting from explosions in a relatively confined space.

Haxdng thus described my invention, it is obvious that various immaterial modifications may 115 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 cover by Letters Patent is:

1. An attachment for a combustible gas conduit providing an enlargement of the conduit, a flame arrestor comprising a plurality of plates arranged to form a stack closing the enlarged portion of the conduit, means holding said plates in spaced apart relation to provide relatively narrow apertures between the plates, the depth 130 of said apertures relative to the width of said plates being such as to extinguish flames in passing therethrough, and a shield member in substantially parallel closely spaced relation to the inlet edges of said plates, said shield member providing a port arranged to direct the gases in a path substant ally transverse to the path of the gases through said apertures.

2. An attachment for a combustible gas conduit providing an enlargement of the conduit, a flame arrestor mounted in said enlarged portion of the conduit comprising a stack of annular plates forming an extension of the conduit into said enlarged portion, a plate closing the end of said extension, means holding said annular plates 14.5 in spaced apart relation to provide relatively narrow apertures therebetween, a plurality of overlapping curved plates closely spaced to and forming an enclosure for said annular plates, the overlapping portion of said curved plates being spaced apart to provide ports through which the gases travel in directions substantially tangcntial to the annular plates.

3. An attachment for a combustible gas conduit providing an enlargement of the conduit, a flame arrestor mounted in said enlarged portion of the conduit comprising a stack of annuia plates forming an extension of the conduit into said enlarged portion, a plate closing the end of said extension, means hol ing said annular plates in spaced apart relation to provide relatively narrow apertures therebetween, a plurality of overlapping curved plates closely spaced to and forming an e closure for said annular plates, the overlapping portion of said curved plates being spaced apart to provide ports through which the gases travel in directions substantially tangential to the plates, the total crosssectional area of said ports and of said apertures each being not than the normal crosssectional area of conduit.

4. An attachment for a combustible gas conduit providing an enlargement or" the conduit, a flame arrestor conrpr ng a p urality of plates arranged to form a stack clo g the conduit, means hol g said plates spaced apart relation to provide relatively narrow apertures between the the depth of said apertures relative to the width of said plates being such as to extinguish flames in passing therethrough, a plurality of members in substantially parallel closely spaced relation. to the inlet edges or" said plates, said members providing a port arranged to direct the gases in a path substantially transverse to the path of the gases through said apertures.

5. An attachment for the end of a combustible gas conduit providing an enlargement of conduit, a arr-ester comprising a plurality of plates arr to form a stack closing the enlarged portion of the conduit, means holding said plates in s aced apart relation to provide relatively narrow horizontal passages between the plates, the depth of passages relative to the width of said plates being such as to extinguish flames in passing therethrough, and a vertical shield member in substantially parallel closely relation to the ir et edges of said plates, said shield member providing a port of a size substantially equal to the width of the conduit arranged to direct the gases in a path substantially transverse to the path of the gases through said apertures.

65. An attachment for a combustible gas conduit providing an enlargement of the conduit, a arrestor comprising a plurality of plates arranged to form a stack closing the enlarged portion of the conduit, means holding said plates in spaced apart relation to provide relatively narrow passages between. the plates, the depth of said passages relative to the width of said plates being such as to extinguish flames in pas ing there hrough, and a vertical shield comprising a pair of members extending inwardly from the sides of the conduit in substantially parallel closely spaced relation to the inlet edges of said plates, said members providing a port arranged to direct the gases in a path of considerable width substantially transverse to the path of the gases through said apertures.

'7. An attachment for a combustible gas conduit providing an enlargement of the conduit, a flame arrester mounted. in said enlarged portion of the conduit comprising a stack of annular plates forming an extension of the conduit into said enlarged portion, a plate closing the end of said extension, means holding said annular plates in spaced apart relation to provide relatively narrow apertures therebetween, two sets of overlapping curved plates, one set arranged within and a second set about the confines of said annu ar plates and forming an enclosure therefor, the overlapping portions of said curved plates being spaced apart to provide ports through which the gases travel in directions substantially tangential to the annular plates.

8. An attachment for a combustible gas conduit providing an enlargement of the conduit, a flame arrester mounted in said enlarged portion of the conduit comprising a stack of annular plates forming an extension of the conduit into said enlarged portion, a plate closing the end of said extension, means holding said annular plates in spaced apart relation to provide relatively narrow apertures therebetween, two sets of overlapping angular plates, one set arranged within and a second set about the confines of said annular plates and forming an enclosure therefor, the overlapping portions of said first mentioned set of angular plates being spaced to provide ports through which the gases travel in directions substantially tangential to the annular plates.

9. An attachment for a combustible gas conduit providing an enlargement of the conduit, a flame arrester mounted in said enlarged portion of the conduit comprising a stack of annular plates forming an extension of the conduit into said enlarged portion, a plate closing the end of said exte. sion, means holding said annular plates in spaced apart relation to provide relatively narrow passages therebetween, two sets of overlapping angular plates, one set arranged within and the other about the confines of said annular plates and forming an enclosure therefor, the overlapping portions of said last mentioned set of angular plates being spaced apart to provide ports through which the gases travel in directions substantially tangential to the annular plates.

10. An attachment for a combustible gas conduit providing an enlargement of the conduit, a flame arrester mounted in said enlarged portion of the conduit comprising a stool: of annular plates forming an extension of he conduit into said enlarged portion, a plate closing the end of said extension, means holding said annular plates in spaced apart relation to provide relatively narrow apertures therebetween, two sets of overlapping angular plates, one set arranged within and a second set about the confines of said annular plates and forming an enclosure therefor, said enlargement of the conduit providing a chamber surrounding the sides and an end of the arrangement formed by all and the overlapping portions or" said first mentioned set of angular plates being spaced apart to provide ports through which the gases travel in directions substantially tangential to the annular plates into and from said chamber into said conduit.

11. An attachment for a combustible gas'conduit providing an enlargement of the conduit. a flame arrestor mounted in said enlarged portion of conduit comp 'ng a stack of annular plates forming an extension of the conduit into said enlarged portion, a plate closing the end of said extension, means holding said annular plates in spaced apart relation to provide relatively narrow apertures therebetween, a plurality of of said plates, 1

overlapping curved plates closely spaced to and forming an enclosure for said annular plates, a plurality of overlapping curved plates closely spaced to and providing a formation within the confines of said annular plates, the overlapping portions of all of said curved plates being spaced apart to provide ports through which the gases travel in directions substantially tangential to the annular plates, the total cross-sectional area of said ports and of said apertures each being not less than the normal cross-sectional area of said conduit.

12. An attachment for a combustible gas conduit providing an enlargement of the conduit, a flame arrestor mounted in said enlarged portion of the conduit comprising a stack of annular plates forming a closed extension of the conduit into said enlarged portion, means holding said annular plates in spaced apart relation to provide relatively narrow apertures therebetween, a plurality of overlapping curved plates closely spaced to and forming an arrangement within the confines of said annular plates, the overlapping portion of said curved plates being spaced apart to provide ports through which the gases travel in directions substantially tangential to the annular plates, the total cross-sectional area of said ports and of said apertures each being not less than the normal cross-sectional area of said conduit.

13. An attachment for a combustible gas conduit comprising a plurality of spaced sets of spaced plates providing passages adapted to be arranged Within and between the ends of a conduit in a manner to receive all of the gas passing therethrough, the passages of one set being arranged transverse to the normal direction of travel of the gas through the conduit, and the passages of a second set of plates being arranged to receive the gas as it enters the attachment and impart rotary movement to the gas and direct same through said first mentioned passages.

14. An attachment for a combustible gas conduit comprising a plurality of spaced sets of spaced plates providing passages adapted to be interposed in a conduit in a manner to receive all of the gas passing therethrough, the passages of one set being arranged transverse to the normal direction of travel of the gas through the conduit, the passages of a second set being arranged to receive the gas entering the attachment and impart rotary movement to the gas and direct same through said first mentioned passages, and a third set arranged to receive the gas as it leaves the passages of said first mentioned set and impart rotary movement to the gas as it leaves the attachment and is conveyed through the conduit coextensive with the direction of the gas entering the attachment.

15. An attachment for a combustible gas conduit including a housing and a plurality of spaced sets of spaced plates providing passages adapted to be interposed in a conduit in a manner to receive all of the gas passing therethrough, said housing providing a chamber surrounding the sides and an end of said sets of plates, the passages of one set of plates arranged transverse to the normal direction of travel or" the gas through the conduit, the passages of a second set being arranged to receive the gas entering the attachment and impart rotary movement to the gas and direct same through said first mentioned passages, and a third set of plates having the passages thereof arranged to receive the gas as it leaves the passages of said first mentioned set and impart rotary movement to the gas as it leaves the attachment and is conveyed through the conduit coextensive with the direction of the gas entering the attachment.

16. An attachment for a combustible gas conduit including a housing and a plurality of spaced sets of spaced plates providing passages adapted to be interposed in a conduit in a manner to receive all the gas passing therethrough, said housing providing a support and a chamber surrounding the sides and an end of said sets of plates, the passages of one set of plates arranged transverse to the normal direction of travel of the gas entering the conduit, and another set arranged whereby the passages thereof receive the gas entering the attachment and impart rotary movement to the gas as it passes through said first mentioned passages into and from said chamber and into said conduit in a direction coextensive with the direction of travel of the gas entering said attachment.

RUDOLPH J. ANSCHICKS.

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