US3042108A

US3042108A - Apparatus for burning liquid fuel

Info

Publication number: US3042108A
Application number: US830139A
Authority: US
Inventors: Boij Karl Oskar Arne; Johansson Bertil Karl Axel
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-08-09
Filing date: 1959-07-28
Publication date: 1962-07-03
Anticipated expiration: 1979-07-03

Description

`uly 3, 1962 K. o. A. Bou ETAL 3,042,103

APPARATUS FORBURNING LIQUID FUEL 2 Sheets-Sheet 1 Filed July 28, 1959 HP11?. Timm@ INVENTORS KARL OSKAR ARNE BOIJ 8 BERTIL KARL AXEL JOHANSSON ATTORNEYS July 3, 1962 K. o. A. BOIJ ETAL 3,042,108

APPARATUS FOR BURNING LIQUID FUEL Filed July 28, 1959 2 Sheets-Sheet 2 INVENTORS KARL OSKAR ARNE BOIJ 8x BERTIL KARL AXEL JOHANSSON ATTORNEYS 3,042,108 APEPARATUS FR BURNKNG LEQUID FUEL Karl @saar Arne Boij, Agatan 5, and Bertil Karl Axel .iohanssom Agatan 26, both of Tranas, Sweden Filed uly 2S, 1959, Ser. No. 830,139 Claims priority, application Sweden Aug. 9, 1953 3 Qlaims. (Cl. 158-94) The present invention relates to apparatus for burning liquid fuel. More particularly the invention relates to apparatus of this kind adapted for burning spirit `and other volatile fuel 'and comprising a fuel container having disposed therein a fuel-absorptive tibrous mass and a wick in contact with this absorptive mass.

The invention has for its principal object to provide a combustion apparatus of the kind referred to which is improved in various respects.

An important object of the invention is to provide a combustion apparatus in which the flame will burn at :a substantially constant intensity as long as there remains any substantial quantity of liquid fuel within the absorptive mass.

Another `object of the invention is to produce a cornbustion apparatus which is spill-proof even for relatively large dimensions of the fuel container and when using a fuel-absorptive charge capable of absorbing a comparatively large quantity of fuel per unit of its volume, and which is at the same time explosion proof.

A further object of the invention is to provide a wick which is capable of being used for a long time without being destroyed, even if `the llame is in direct contact with the wick.

It is also an object of the invention to provide suitable means for adjusting the size of the flame, vand possibly also for preventing any volatilization of fuel from the wick when the combustion apparatus is extinguished.

Other objects and advantages of the invention will be set forth in the following detailed description of a practical embodiment thereof in conjunction with the accompanying drawings, in which:

FIG. l is a vertical section through a combination cooking -and heating stove to which the invention is applied, while FIGS. 2 and 3 show `horizontal cross-sections taken along the lines II-Il and III-HI, respectively, in FIG. l.

Referring to the drawings, numeral designates a closed cylindrical fuel container having a diameter substantially greater than its height. Secured in a central opening in the top wall of the container is a tube 11 for supporting a wick element designated generally by 12. The supporting tube 11 has its top portion projecting by a substantial `amount above the top wall of the container, while its lower portion projects into the interior of the container 10 by an amount corresponding `approximately to `one third of the container height. Inserted centrally in the supporting tube 11 is a narrow filling pipe 13 which serves as an internal supporting tube for the `annul-arly cross-sectioned wick 12, is secured to the bottom wall of the container 10, and is provided adjacent to the latter with a` number `of outlet apertures 14 for the fuel. Obviously, fuel can only be filled into the container 10 up to the bottom end of the supporting tube 11 since, after the fuel reaches this level, an air-pad will form preventing the spirit or other fuel from rising noticeably higher within the container.

The fuel container 10 is lilled up to the level coincident with the bottom end of the supporting tube 11 with a iibrous mass 15 which is capable of absorbing land retaining a substantial amount of liquid fuel per unit volume of the mass. In the embodiment illustrated, the absorptive mass 15 is assumed to consist of a punched-out an- Q n'lCC BMZMS Patented .iuly 3, 1962 nulus of mineral wool in which the fibres have `a substantially horizontal orientation. The average thickness of `the libres of the yabsorption mass may suitably be 1.6-10*L1 to 2.4-104 inches (0.004 to 0.006 millimeters). Generally, the iibre thickness of the labsorptive mass, or the degree of compaction thereof, respectively, will be so chosen as to form a system of capillaries which is capable of absorbing and retaining therein a maximum amount of liquid fuel.

The space above the absorptive mass 15 is iilled with la mass 16 providing for comparatively large voids in rcommunication with each other, such as wood wool or the like, so that 'the mass will only show a limited absorption and retaining capacity for liquid fuel. Yet, the pores of the filling mass 16 must be `suiiiciently small to exclude a'ny danger of ignition of explosive gases accumulating within the pores. The portion of the container 10 receiving the filling 16 with wide pores or voids is intended to serve as an auxiliary space for receiving such liquid fuel `as cannot be retained by the absorptive mass l5 if the wide container 10 should be laid down on its side. Upon placing the container 10 on its bottom again, the fuel received in the voids of the wood wool filling will flow back into the absorptive mass to be absorbed by the latter. Thus the apparatus shown in completely spillproof.

The wick 12 is made of synthetic fibres, for instance glass fibres or nylon fibre-s. The wick is passed downwardly, into close proximity with the bottom of the container 10, through la hole in the absorptive annulus 15, j

the Wick intimately contacting the walls of said hole so as to cause the system of capillaries in the wick to conimunicate with the system of capillaries in the -absorptive mass. In order to obtain an increased area of contact between the wick and the absorptive mass, the lower portion 17 of the wick m-ay be enlarged in a substantially conical or mushroom-like fashion, as indicated in the drawing. The portion ofthe wick 12 disposed within the supporting tube 11 and projecting upwardly from the latter is surrounded by a sleeve 18 made of a porous and heat yresistant material, such as asbestos cloth, and passed over the asbestos sleeve 18 is a protective sleeve 19 of wire gauze or the like.

The glass fibres of the wick 12 are substantially thinner than those of the absorptive mass 15 and. may, for eX- ample, be of a average thickness of no more than 0.-1-10"4 to 0.8- l0*4 inch (0.00l to 0.002 millimeters). This means that, for substantially equal degrees of compaction of the wick and the absorptive mass, the capillaries of the wick, on an average, are considerably liner than the capillaries of the absorptive mass. Therefore, the capillary forces in the wick will be much in excess of the capillary forces in the absorptive mass, whereby the wick will remain saturated with fuel even after the major portion of the fuel originally received in the absorptive mass has been consumed. This, in its turn, will result in that the burner will operate with a substantially constant flame almost until all the fuel hais been consumed, whereas, with substantally equal libre gauges, or `capillarities, of the wick and lthe absorptive mass, the concentration of fuel in the wick would decrease at the same rate yas the `fuel concentration in the absorptive mass, thus resulting in a continuously decreasing iiame.

To enable the iiame size to be adjusted, a tube 20 is provided which is telescoped over the supporting tube 11 so as to `be displaceable lengthwise along the latter by the aid of a control mechanism. In the embodiment shown, said mechanism comprises a U-shaped lever 21 which is pivotally connected to the container top wall at 22 and adapted to cooperate with a pair of lugs 23 projecting from the `adjusting tube 210. At its end remote from the pivot 22 the lever 21 is formed with a horizonaoaatos 3 tally extending slot 24 engaged by a crankpin 25 formed on a control crank 27 having a finger grip 26 and being rotatably mounted in a support Z8 projecting upward from the container top wall. As shown in the drawing, the crank 27 is displaceable endwise in the support 28 between an inner and an outer limit position.

As illustrated in the drawings, the apparatus for burning liquid fuel as described is intended to serve as the source of heat of a combination cooking and heating stove. The combustion -apparatus is disposed on the bottom wall of a cylindrical receptacle 30 within which the fuel container is located in a centered position by four leaf springs 31 secured to the inner wall surface of the receptacle. The springs 31 are formed with shoulders 32 having supported on them a plate 33 formed centrally with a wide opening 34 through which the supporting tube 11 for the wick projects upward by a small amount. The plate 33 protects the fuel container 1t? against radiation of heat from the flame and directs the air for the combustion admitted below inwardly towards the annular clearance between the adjusting tube and the edge of the opening. Supported on the plate 33 is a arne diffuser 35 which is invertedly cup-shaped and is formed in its bottom with a circumferential row of flame-egress apertures 36. In its top limit position the adjusting tube 2t) engages the cup-bottom whereby the flame is extinguished, after which any volatilization of fuel from the wick is effectively prevented. The fiame diffuser cup 35 is maintained in a centered position by four vanes 37 secured to the plate 33, as by screws, and on which a cooking vessel, a grill 38 or the like may be placed. Provided in the lower portion of the side wall of the protective receptacle Sti-the latter being of a height sufficient to afford a Windshield for a cooking vessel placed on the vanes 37-are a plurality of air-draught holes 39.

When the apparatus is to be used as a heating stove, a cover or cowl 49 is placed on the receptacle 3f), said cowl having about its periphery a circumferential row of spaced outlet openings 41 for the gases of combustion and the heated air. For moving and handling the heating stove, the cover 40 may be placed upside down, as indicated in broken lines, thus reducing the height of the apparatus.

It should be understood, of course, that the invention is not limited to the embodiment described in detail hereinbefore and as illustrated in the drawings, since various modifications thereof are conceivable within the scope of the invention.

What we claim is:

l. In apparatus for burning volatile liquid, the combination comprising a fuel container closed except for an opening in the top thereof, a layer of closely compacted and fuel absorptive fibrous material filling said container from the bottom thereof to a predetermined highest fuel level, a layer of relatively loosely compacted and porous material in said container above said closely compacted absorptive material, each of said layers being substantial in depth relative to the other, and said porous material having therein voids and passages sufficiently large to keep liquid fuel from being drawn thereinto by capillary action from said absorptive fibrous material yet sufhciently small to inhibit any dangerous accumulation of explosive gases, a wick extending upwardly through said closely compacted absorptive material and said loosely compacted porous material and thence through said top opening, thereby to draw liquid fuel from the container by capillary action, and means circumscribing said top opening and extending from the top of said container between the wick and the loosely packed material to prevent the flow of liquid from the loosely packed i material through said top opening when the container is positioned on the side thereof.

2. In apparatus for burning volatile liquid, the combination comprising a fuel container closed except for an opening in the top thereof adapted to be occupied by a wick, a layer of closeiv compacted and fuel absorptive fibrous material filling said container from the bottom thereof to a predetermined highest fuel level, a mass of material filling the space in said container between said predetermined highest fuel level and the top of said container, said last-mentioned mass of material including a layer of relatively loosely compacted and porous material immediately .above and adjacent to said closely compacted absorptive material and occupying at least a portion of the space in said container between said predetermined highest fuel level and the top of said container, each of said layers being substantial in depth relative to the other, and said porous material having therein voids and passages sufficiently large to keep liquid fuel from being drawn thereinto by capillary action from said absorptive fibrous material yet sufficiently small to inhibit any dangerous accumulation of explosive gases, a wick occupying said opening and extending therethrough upwardly from said absorptive and porous materials to the outside of the container, thereby to draw liquid from the container by capillary action, and means circumscribing said top opening and extending from the top of said container between the wick and the loosely packed material to prevent the ow of liquid from the loosely packed material through said top opening when the container is positioned on the side thereof.

3. in apparatus for burning volatile liquid, the combination comprising a fuel container closed except for an opening in the top thereof adapted to be occupied by a wick, a layer of closely compacted and fuel absorptive fibrous material filling said container from the bottom thereof to a predetermined highest fuel level, a layer of relatively loosely compacted and porous material filling said container from said predetermined highest fuel level to the top of said container, each of said layers being substantial in depth relative to the other, and said porous material having therein voids and passages sufficiently large to keep liquid fuel from being drawn thereinto by capillary action from said absorptive fibrous material yet sufficiently small to inhibit any dangerous accumulation of explosive gases, a wick occupying said opening and extending therethrough upwardly from said absorptive and porous materials to the outside of the container, thereby to draw liquid from the container by capillary action, and means encircling said top opening and extending from the top of said container between the wick and the loosely packed material to prevent the flow of liquid from the loosely packed material through said top opening when the container is positioned on the side thereof.

References Cited in the file of this patent UNITED STATES PATENTS 395,730 Anderson Ian. 8, 1889 439,560 Reinhold Oct. 28, 1890 564,991 Gregory Aug. 4, 1896 911,622 Smith Feb. 9, 1909 1,638,498 McNutt Aug. 9, 1927 2,086,639 Reese July 13, 1937 2,441,242 Harkins May 1l, 1948 2,879,837 Downs Mar. 31, 1959 FOREGN PATENTS 18,415 Great Britain 1891 infr; .5mm