US2990879A - Burner for volatile fuels - Google Patents

Description

July 4., 1961 E. FUCHS ETAL BURNER FOR VOLATILE FUELS 2 Sheets-Sheet 1 Filed March 12, 1957 July 4, 1961 E. FUCHS ET AL 2,990,879 BURNER FOR VOLATILE FUELS Filed March 12, 1957 2 Sheets-Sheet 2 II I/IIIIIII/ I United States Patent 2,990,879 BURNER FOR VOLATILE FUELS Erich Fuchs, Stockdorf, near Munich, and Rudolf Reinhardt, Krailling, near Munich, Germany, assiguors to Wilhelm 'Baier K.G., Stockdorf, near Munich, German y Filed Mar. 12, 1957, Ser. No. 645,451 Claims priority, application Germany Mar. 21, 1956 17 Claims. (Cl. 15877) The present invention relates to burners.

More particularly, the present invention relates to burners which are adapted to burn fuel in atomized condition.

Burners of the above type which are used for burning relatively viscous, heavy fuels need not be constructed to prevent flashback of a flame which burns the fuel in atomized condition, because the boiling point of such heavy fuels is too high to provide any fuel vapors which are capable of carrying the flame back to the parts of the burner which drive the same and which are located to the rear of the combustion chamber. However, burners which burn light, volatile fuels such as gasoline, for example, must be constructed to prevent flashback. Moreover, with such burners, bubbles or the like sometimes form in the fuel lines to temporarily interrupt the flow of fuel, with the result that the flame becomes extinguished and then after the flame is extinguished the fuel continues to flow so as to flood the burner undesirably.

One of the objects of the present invention is to provide a burner for volatile fuels which capable of preventing flashback.

Another object of the present invention is to provide a burner for volatile fuels which is capable of reliably maintaining a fuel supply to prevent a flame from becoming extinguished even if the flow of fuel should be temporarily interrupted by the formation of bubbles or the like in the fuel lines.

Another object of the present invention is to provide a structure capable of accomplishing the above objects and composed of simple and ruggedly constructed elements which are veny reliable in operation.

Still another object of the present invention is to pro vide a burner whose components lend themselves to economical mass production. 7

With the above objects in view the present inventio mainly consists of a burner which includes a supply means for supplying a volatile fuel which is to be burned in atomized condition. A reservoir means communicates with the supply means for receiving fuel therefrom, and this reservoir means'forms a body of fuel having a free fuel surface. A pair of discharge means communicates with the reservoir means for discharging fuel therefrom, and one of these discharge means is located nearer to the free surface of the fuel than the other, so that if the fuel supply is temporarily interrupted, the flow of fuel through the discharge means nearer to the free fuel surface may stop while the flow of fuel will continue through the other discharge means until the flow from the supply means again starts. A spray means communicates with the reservoir means for spraying fuel therefrom.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as FIG. 1 is a sectional elevational view of one possible I 'ice embodiment of a burner according to the present inventron;

FIG. 2 is a sectional plan view taken along the line 11-11 of FIG. 1 in the direction of the arrows;

FIG. 3 is a sectional elevational view of another embodiment of a burner according to the present invention;

FIG. 4 is a partly sectional elevational view of a further embodiment of a burner according to the present invention; and

FIG. 5 is a sectional elevational view of a still further embodiment of a burner according to the present invention.

Referring now to FIGS. 1 and 2, the structure of the invention illustrated therein includes a drive shaft 1 which is rotatable about its axis and which is rotated by any suitable drive means (not shown). This embodiment includes a supply means in the form of a supply tube 11 communicating with any pump or the like which pumps fuel from any suitable source through the pipe 11 to its open discharge end 15. A reservoir means communicates with the supply means 11 and is in the form of a stationary container 10 having a bottom wall through which the supply tube 11 passes in the manner shown in FIG. 1. The stationary container 10 has in its inten'or during operation of the burner a body of fuel which may have a free top surface engaging or located slightly beneath the top wall of the container 10.

A pair of discharge means communicate with the container 10 and are in the form of the discharge tubes 13 and 14 which communicate with the container 10 and extend forwardly therefrom to the left, as viewed in FIG. 1. It will be noted that the discharge tube 13 is higher than the discharge tube 14 by the elevation h.

With this construction, if bubbles or the like should form in the supply means 11, for example, so as to 'ina terrupt the flow of fuel temporarily, the free top surface of the body of fuel in the container 10 may fall, so as to stop the flow of fuel through the discharge; tube 16:, but the flow of fuel will continue through the discharge tube 14, and the elevation h is carefully chosen so as to guarantee the flow of fuel through the discharge tube 14 until the flow through the tube 11 again starts. It will be noted from FIG. 2 that the supply tube 11 is asymmetrically arranged with respect to the container 10, so that no bubbles or the like can flow directly from the tube 11 into the tube 13, for example, to interrupt the flow of fuel therethrough.

A spray means communicates with the pair of discharge tubes 13 and 14 for receiving fuel therefrom and for spraying the fuel in atomized condition so that the fuel is then burned in atomized condition. This spray means includes a hollow, annular enclosure 2 fixed coaxially to the shaft 1 for rotation therewith. The manner in which the enclosure 2 is fixed to the shaft 1 is described below. The enclosure 2 has a front wall located to the left, as viewed in FIG. 1, which is joined at its inner periphery to the shaft 1 and the hollow enclosure 2 has a rear wall formed with a central opening or cutout 12 through which the discharge tubes 13 and 14 extend into the enclosure tube so as to deliver fuel thereto.

A pair of spray tubes 3 and 4 are fixed to and extend forwardly from the front wall of the enclosure 2. These tubes 3 and 4 communicate at their rear ends with the interior of the enclosure 2 so as to receive fuel therefrom and it will be noted that the spray tubes 3 and 4 are respectively located on opposite sides of the shaft 1 and have free ends distant from the enclosure 2 which are located at a greater distance from the axis of the shaft 1 than the ends of the tubes 3 and 4, which are fixed to the enclosure 2. Thus, the spray tubes 3 and 4 areinclined with respect to the axis of the shaft 1.

A blower means cooperates with the spray means 2-4 in order to cool the latter so as to maintain fuel in the enclosure 2 at a temperature low enough to prevent flashback. This blower means includes the blower impeller 6 which is fixed to the shaft 1 for rotation therewith. It will be noted that the enclosure 2 extends partly into the impeller 6 while the latter is located for the most part forwardly of the enclosure, the spray tubes 3 and 4 passing through suitable openings in the front wall of the impeller 6.

The front wall of the enclosure 2 is located just in front of and against a shoulder of the shaft 1, and a flanged sleeve 7 extends through the central opening of the impeller 6 and has a rear end engaging the front wall of the enclosure 2. A nut 9 is threaded on the shaft 1 and presses against a washer which in turn presses against the flanged sleeve 7 so that the latter presses the front wall of the enclosure 2 against the shoulder of the shaft 1 to fix the spray means 2-4 to the shaft 1 for rotation therewith. It will be noted that a spacer sleeve 8 is located between and presses against the front wall of the impeller 6 and the front wall of the enclosure 2.

With this construction, if because of the formation of bubbles or the like the supply of fuel is temporarily stopped, sufficient fuel will flow through the discharge tube 14 to spray means 2-4 to maintain a flame in the burner and before the level of the fuel in the reservoir means 10 reaches the lower discharge tube 14, the flow of fuel to the reservoir means will again have started in all cases.

FIG. 3 shows a spray means identical with that of FIG. 1 except that the tube 4 is replaced by a tube 16 which is located nearer to the axis of the enclosure 2' than the tube 3. This structure of FIG. 3 may replace the spray means 2-4 in the organization shown in FIG. 1, and it will be noted that with the construction of FIG. 3, if the supply of fuel should terminate temporarily, the annular free surface of the annular body of fuel formed by centrifugal action in the enclosure 2 will recede from the axis of the enclosure 2, so that the flow of fuel may terminate temporarily through the spray tube 16 but will continue through the spray tube 3' to maintain the flame until the normal flow of fuel starts again. If desired, the container 10 and tubes 13 and 14 of FIG. 1 may be omitted and the supply tube 11 may discharge directly into the enclosure 2' through the opening or cutout 12' of FIG. 3. In this case, the enclosure 2' forms a reservoir means which provides an annular body of fuel having an annular free surface with the tube 16 located nearer this free surface than the tube 3'. Thus, with the embodiment of FIG. 3, the enclosure 2' may form the reservoir means while the tubes 3 and 16 form a pair of discharge means communicating with the reservoir means and the outer free ends of the tubes 3' and 16 form a spray means which receives the fuel from the discharge means for spraying the fuel.

In the embodiment shown in FIG. 4, a pump 17 whose construction forms no part of the present invention, sucks fuel from a suitable tank (not shown) through the suction line 18 and discharges the fuel through the pressure line 19 to a reservoir means formed by the container 20 which is stationary. Thus, in this embodiment, parts 17-19 form a supply means for supplying fuel to the reservoir means 20. It will be noted that with this embodiment the pressure line 19 discharges through the top wall of the container 20 into the interior thereof. A pair. of discharge tubes 22 and 23 are respectively located at different elevations and communicate with the interior of the container 20. The container 20 is closed at its bottom by a threaded plug 21 which can simply be removed from the container 20 whenever it is desired to empty the latter. In assembling the discharge tubes 22, 23 with the container 20, these tubes 22 and 23 are simply passed through a pair of openings in a side wall portion of the container 20 until the ends of the tubes 22 and 23 abut against or are located closely adjacent to a part of the container 20 opposite the portion thereof formed with the openings through which the tubes 22 and 23 respectively extend. These tubes 22 and 23 are soldered to the container 20 at the openings of the latter through which these tubes extend, respectively, and because of the fact that the tubes 22 and 23 extend across the interior of the container 20, the open ends of the tubes 22 and 23 which communicate with the interior of the container 20 cannot become plugged up with the solder. It will be noted that the open ends 24 and 25 of the tubes 22 and 23, respectively, are beveled so that these openings are not closed by engagement with an inner surface of the container 20.

The discharge tubes 22 and 23 communicate with a spray means fixed to a shaft 31 for rotation therewith in the same way that the spray means 2-4 of FIG. 1 is fixed to the shaft 1. This spray means of FIG. 4 includes an annular enclosure 27 whose front wall 33 is fixed directly to the shaft 31 for rotation with the latter and whose rear wall is formed with an opening through which the discharge tubes 22 and 23 pass into the interior of the enclosure 27. A pair of spray tubes 28 and 29 similar to the spray tubes 3 and 4 of FIG. 1 are fixed to the front wall 33 of the enclosure 27 for rotation with the latter and the front wall 33 is formed with openings respectively communicating with the spray tubes 28 and 29. A blower impeller 30 is also fixed to the shaft 31 for rotation therewith and it will be noted that the enclosure 27 is located within the impeller 30 but rearwardly of the front wall of the latter, this front wall being formed with openings through which the tubes 28 and 29 respectively pass. Thus, the blower impeller 30 will cool the enclosure 27 so as to maintain fuel therein at a temperature low enough to prevent flashback. As further assurance against flashback, the front end of the shaft 31 fixedly carries a cup-shaped member 32 which serves to displace air and to screen the structure of FIG.

4 against heat from the combustion chamber.

-It is believed to be apparent that the construction of FIG. 4 will also function according to the present invention in that if the fuel supply should be temporarily interrupted in the supply means 17-19 so that the level of the fuel in the container 20 falls below the inlet end 24 of the discharge tube 22, nevertheless suflicient fuel will continue to flow through the discharge tube 23 to maintain the flame until the flow of fuel from the supply means again starts.

A particular feature of FIG. 4 resides in locating the free ends 35 and 34 of the tubes 22 and 23 closely adjacent to the front wall of the enclosure 27 and preferably at a distance less than 1.5 mm. therefrom. In this way, there will be no tendency of the fuel leaving the tubes 22 and 23 to spray rearwardly from the front will} 33 of the enclosure 27 after impinging on this front w FIG. 5 of the drawings shows a burner construction which is particularly suited for mass production because of the simplicity of the construction of the parts shown in FIG. 5. Referring to FIG. 5, a pump 44, whose construction forms no part of the present invention, delivers fuel under pressure to the pressure conduit 45 which delivers the fuel from the pump to a stationary reservoir means 48. This reservoir means 48 is in the form of an annular container surrounding and slightly spaced from the drive shaft 36.

The container 48 is fixed directly to the pump 44 by bolts 50 passing respectively through openings 51 of the container 48, only onebolt 50 being shown in FIG. 5. The container 48 is formed with a passage 46 communicating with the pressure conduit 45 of the supply means 44, 45, and the container 48 is formed with another chamber 49 of the container 48, this annular chamber 49 being limited adjacent the shaft 36 by the inner annular wall 52 of the container 48, this wall 52 being coaxial with and of an inner diameter slightly greater than the shaft 36. The container 48 terminates at its front end in a substantially vertical annular wall formed with a pair of openings 55 and 56 located at different elevations, the opening 55 being higher than the opening 56. Thus, the portions of the front wall of the container 48 which are respectively formed with the openings 55 and 56, form the pair of discharge means for the embodir'nent of FIG. 5. The front wall of the container 48 terminates in an annular lip 53 of frustro-conical configuration. In the embodiment of FIG. spray means communicate with the reservoir means 48 to receive the fuel from the pair of discharge means 55 and 56, and this spray means'is inthe form of an' enclosure 37 which is of annular configuration and which is fixed coaxially to the shaft 36 for rotation therewith. The enclosure 37 has a front wall 54 fixed to the shaft 36 and a rear wall formed with a central opening through which the reservoir means 48 passes into the interior of the enclosure 37. It will be noted that the lip 53 extends almost up to the front wall 54 of the enclosure 37 and this lip 53 is. spaced from the front wall 54 preferably by a distance'less than 1.5 mm., so that the fuel leaving the lip 53 will'have no tendency to spray rearwardly.

The spray means further includes a pair of spray tubes 38 and 39 fixed to and extending forwardly from the front wall 54 of the enclosure 37 and respectively commimicating with openings 57 and 58 formed in the front wall 54 so that in this way fuel flows from the enclosure 37 to the tubes 38 and 39 to issue from the latter in the form of an atomized spray.

The embodiment of FIG. 5 also illustrates a blower means for cooling the spray means 3739 so as to maintain the fuel of the spray means at a temperature low enough to prevent flashback. This blower means includes the blower impeller 43 which is fixed at its front wall '42 to the shaft 36 for rotation therewith. It will be noted that the enclosure 37 has its front wall 54 located to the rear of the front wall 42 of the impeller 43 although the entire enclosure 37 is located within the impeller 43. The front wall of the impeller is formed with a pair of openings 40 and 41 through which the spray tubes 38 and 39 respectively pass.

It is believed to be apparent that with the embodiment of FIG. 5, if the flow from the supply ineans'44, 45 to the reservoir means 48 should terminate temporarily, the body of fuel in the stationary container 48 may have its top free surface fall below the opening 55 so as to terminate the how of fuel through the discharge means formed by the opening 55, but nevertheless the flow will continue through the discharge means 56 to an extent suflicient to maintain the flame and for a length of time greater'than that required for the ilow to start again.

It will be noted that the embodiment of FIG. 5 is extremely compact and occupies a relatively small space. Furthermore, it is impossible with this, as well as with the other embodiments of the invention, for the openings through. which the fuel passes to the ends of the spray tubes to become coked up when the operation of the burner terminates due to flashback anclburning of residual amounts of'fuel in the spray means.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of burners differing from the types described above.

While the invention has been illustrated and described as embodied in burners for volatile liquids, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention, and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a burner, in combination, supply means for supplying a volatile liquid fuel which is to be burned in atomized condition; reservoir means having a normal free surface level and communicating with said supply means for receiving fuel therefrom and for forming a body of fuel having a free surface at said level; a pair of separate discharge means communicating with said reservoir means for discharging fuel therefrom, one of said discharge means being located nearer to said free fuel surface level than the other so that if the supply of fuel from said supply means to said reservoir means is temporarily interrupted, the flow of fuel through said one discharge means may stop while the flow of fuel will continue through said other discharge means; and spray means communicating directly with each of said pair of discharge means for receiving fuel independently from each of said discharge means and for spraying the fuel in atomized condition so that when flow through one of said discharge means is temporarily interrupted flow of fuel to said spray means will be maintained.

2. In a burner as recited in claim 1, said reservoir means being in the form of a hollow container having a predetermined axis and being rotatable about its axis so that the body of fuel is annular and adjacent the inner Wall of said container, said discharge means being in the form of a pair of tubes connected to and communicating with said container, with one of said tubes communicating with said container at a portion thereof nearer to said axis than the portion of said container with which the other tube communicates and said spray means being formed by outer open end portions of said tubes.

3. In a burner according to claim 1, said reservoir means being in the form of a stationary container and said pair of discharge means being respectively located at different elevations with said one discharge means being located higher than the other, said spray means being in the form of a hollow enclosure having a predetermined axis and being rotatable about said axis and a pair of tubes fixed to said enclosure for rotation therewith, communicating with the interior thereof, and extending therefrom.

4. In a burner as recited in claim 3, said pair of discharge means being in the form of a pair of tubes communicating with said container and extending into said enclosure.

5. In a burner as recited in claim 3, said pair of discharge means being in the form of a pair of wall portions of a wall of said container, said container wall being located in said enclosure and said pair of wall portions 'being respectively formed with openings through which fuel flows from said container into said enclosure.

6. A burner as defined in claim 3 and including a shaft rotatable about its axis, said hollow enclosure being fixed coaxially to said shaft for rotation therewith and having a front wall and a rear wall, said rear wall being formed with a central cut-out, said pair of tubes of said spray means being fixed to said front wall of said enclosure respectively at opposite sides of said axis and extending forwardly from said front wall, said pair of discharge means being in the form of a pair of discharge tubes passing through said central cut-out of said rear wall of said enclosure, and said burner including further a supply tube communicating with the interior of said container for supplying fuel thereto.

7; A burner as defined in claim 6 in which said supply tube is asymmetrically arranged with respect to said container.

8. A burner as defined in claim 7 in which said supply tube communicates with said container through a bottom wall thereof.

9. A burner as defined in claim 6 in which said supply tube communicates with said container through a top wall thereof.

10. A burner as defined in claim 6 in which said discharge tubes extend almost to said front wall of said enclosure.

11. A burner as defined in claim 10 in which said discharge tubes are spaced from said front wall by a distance less than 1.5 mm.

12. In a burner as recited in claim 6, said pair of discharge tubes passing through a wall portion of said container across the interior thereof and respectively having beveled open ends located adjacent a part of said container opposite from said wall portion thereof.

13. In a burner, in combination, supply means for supplying a volatile liquid fuel which is to be burned in atomized condition; reservoir means having a normal free surface level and communicating with said supply means for receiving fuel therefrom and for forming a body of fuel having a free surface at said level; a pair of separate discharge means connnunicating with said reservoir means for discharging fuel therefrom, one of said discharge means being located nearer to said free fuel surface level than the other so that if the supply of fuel from said supply means to said reservoir means is temporarily interrupted, the flow of fuel through said one discharge means may stop while the flow of fuel will continue through said other discharge means; spray means communicating directly with each of said pair of discharge means for receiving fuel independently from each of said discharge means and for spraying the fuel in atomized condition so that when flow through one of said discharge means is temporarily interrupted flow of fuel to said spray means will be maintained; and blower means cooperating with said spray means for cooling the same.

14. In a burner, in combination, supply means for supplying a volatile liquid fuel which is to be burned in atomized condition; reservoir means having a normal free surface level and communicating with said supply means for receiving fuel therefrom and for forming a body of fuel having a free surface at said level; a pair of separate discharge means each having substantially the same cross section communicating with said reservoir means for discharging fuel therefrom, one of said discharge means being located nearer to said free surface level than the other so that if the supply of fuel from such supply means to said reservoir means is temporarily interrupted, the flow of fuel through said one discharge means may stop while the flow of fuel will continue through said other discharge means; and spray means communicating directly with each of said pair of discharge means for receiving fuel independently from each of said discharge means and for spraying the fuel in atomized condition so that when flow through one of said discharge means is temporarily interrupted flow of fuel to said spray means will be maintained.

15. In a burner, in combination, a shaft rotatable about its axis; a hollow annular enclosure fixed to said shaft for rotation therewith, said enclosure having a front wall and a rear wall and said rear wall being formed with a central opening passing therethrough; a pair of spray tubes fixed to said front wall of said enclosure, communicating with the interior of said enclosure and extending forwardly therefrom; a stationary container forming a fuel reservoir, said container being annular and surrounding said shaft and said container extending forwardly through said opening of said rear wall of said enclosure into the interior of thelatter, said container having in said enclosure a front wall formed with a pair of openings located respectively at diflferent elevations, and said front wall of said container terminating in an annular lip extending forwardly toward said front wall of said enclosure and extending almost up to said front wall of said enclosure; and supply means communicating with said container for supplying fuel thereto.

16. In a burner, in combination, a shaft rotatable about its axis; a hollow annular enclosure fixed to said shaft for rotation therewith, said enclosure having a front wall and a rear wall and said rear Wall being formed with a central opening passing therethrough; a pair of spray tubes fixed to said front wall of said enclosure, communicating with the interior of said enclosure and extending forward therefrom; a stationary container forming a fuel reservoir, said container being annular and surrounding said shaft and said container extending forwardly through said opening of said rear wall of said enclosure into the interior of the latter, said container having in said enclosure a front wall formed with a pair of openings located respectively at different elevations, and said front wall of said container terminating in an annular lip extending forwardly toward said front wall of said enclosure and extending almost up to said front wall of said enclosure, said lip being spaced from said front wall of said enclosure by a distance less than 1.5 mm.; and supply means communicating with said container for supplying fuel thereto.

17. In a burner, in combination, a shaft rotatable about its axis; a hollow annular enclosure fixed to said shaft for rotation therewith, said enclosure having a front wall and a rear wall and said rear wall being formed with a central opening passing therethrough; a pair of spray tubes fixed to said front wall of said enclosure, communicating with the interior of said enclosure and extending forwardly therefrom; a stationary container forming a fuel reservoir, said container being annular and surrounding said shaft and said container extending forwardly through said opening of said rear wall of said enclosure into the interior of the latter, said container having in said enclosure a front wall formed with a pair of openings located respectively at different elevations, and said front wall of said container terminating in an annular lip extending forwardly toward said front wall of said enclosure and extending almost up to said front wall of said enclosure, said lip having a frustro-conical configuration; and supply means communicating with said container for supplying fuel thereto.

References Cited in the file of this patent UNITED STATES PATENTS 752,900 Gibbs Feb. 23, 1904 2,049,730 Bersey Aug. 4, 1936 2,416,932 Litenberg Mar. 4, 1947 2,429,739 Arnhym Oct. 28, 1947 2,566,692 Chandler Sept. 4, 1951 2,690,766 Breese Oct. 5, 1954

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