US2864439A

US2864439A - Arrangement for feeding and burning liquid fuel

Info

Publication number: US2864439A
Application number: US528473A
Authority: US
Inventors: Linde Robert Von; Baier Walter
Original assignee: Wilhelm Baier KG
Current assignee: Wilhelm Baier KG
Priority date: 1954-08-23
Filing date: 1955-08-15
Publication date: 1958-12-16
Anticipated expiration: 1975-12-16

Description

Dec. 16, 1958 2,864,439

ARRANGEMENT FOR FEEDING AND BURNING LIQUID FUEL R. VON LINDE ETAL Filed Aug. 15, 1955 IN VE N T025 Rube/'2 van Linde 8 h/a/ferBaier United States Patent ARRANGEMENT FOR FEEDING AND BURNING LIQUID FUEL Robert Von Linde, Grafelfing, and Walter Baler, Stockdorf, near Munich, Germany, assignors to Wilhelm Baier K. G., Stockdorf near Munich, Germany Application August 15, 1955, Serial No. 528,473 Claims priority, application Germany August 23, 1954 9 Claims. (Cl. 158-5) This invention relates to a method and a device for supplying consumers, and more particularly burners, with liquid fuel and has special reference to a further improvement of the device described in our copending application Serial No. 443,128, filed July 13, 1954, said device comprising an ascending tube or riser provided in the fuel ducts leading from the supply tank to the burner or other consumer, so as to ascend to a level above the level in the supply tank, and being exposed to the action of heat at least in its-part below the supply tank level, to such an extent that the difference between the two levels is overcome.

It is an object of the present inventionto provide a further improvement of this device, in such a way that even considerable differences of level between the supply tank and the consumer can be overcome.

A special object of the invention is to provide an In the accompanying drawings a now preferred embodiment of the invention is shown by way of illustration and not by way of limitation. I

The figure is a side view of anoven, stove, or furnace including a fuel supply system having the invention applied thereto, partly in an axial section.

The exhaust gases of the oven 1 are discharged through a chimney 2. Mounted on the oven and ending in a combustion chamber in its interior is a funnel-shaped burner 3 which is supplied with evaporated fuel through an evaporator reservoir orv vaporizer 4 and a pipe 5.

' The right end of the burner 3, where the fuel supply arrangement in which the means on the supply tank suggested in our said copending patent application for keeping the fuel at a constant level can be dispensed with.

With these and further objects in view, according to the present invention the action of heat upon the part of the ascending pipe or riser communicating with the supply tank is increased to such an extent that the liquid in the riser is at least partly evaporated. This intensive development of heat offers the advantage that the pressure in the evaporating burner can be kept constant with the aid of an overflow reservoir, the difference of the level in the overflow reservoir and the variable level in the supply tank being overcome without difliculty by heating and partly evaporating the liquid fuel in the heated portion of the riser. The fuel entering into the overflow vessel from the heated riser is fed downwards, e. g., to an evaporation burner, excessive fuel flowing from the overflow reservior directly into the fuel tank through a cooled return pipe. In order to prevent vapors from accumulating in the overflow reservoir, which vapors might cause variations of disturbances, the overflow reservoir is connected to the chimney of the oven, stove or furnace. I

According to a further feature of the present invention, referring to its application for the supply of burners with liquid fuel, the overflow reservoir is constructed in such a way that the fuel volume available therein including the column of liquid in the connecting pipe to the evaporation burner is smaller than the volume of the evaporation receptacle. Hence, when the heating device is put pressure in the evaporating burner or other out of operation, for example, by accidental interruption of the supply of fuel to the heated riser, the burner flame will go out for lack of evaporated fuel. As the evaporation reservoir then remains partially filled with fuel,the

latter can evaporate if the burner is lighted again, as by pipe 5 enters, isopen, whereby an annular slot is provided around this fuel pipe 5. Through said slot, air is sucked into the burner for the combustion of the fuel when the fuel is fed from the reservoir 4 through the pipe 5. This annular slot, known per se, is not visible in the drawing. The evaporator reservoir 4 through a pipe 6 is connected to an overflow reservoir 7 which in turn is supplied with fuel from a fuel tank 11 through pipes 8, 9, of which the latter is descending, and an ascending pipe, of which a portion 10 passes through the combustion chamber to be intensively heated. The interconnected pipes 9 and 10 constitute the legs of a U-shaped pipe system. Moreover, through a pipe 12 the overflow reservoir 7 is connected to the chimney 2 of the oven 1. A further branch pipe 13, provided with cooling ribs 14, serves to return ingly the pressure under which the fuel is fed to the burner is kept constant with the result that a very uniform fuel supply is ensured.

The fuel feeding device shown in the as follows: I

In order to put the burner into operation, the small supply of liquid fuel always remaining in the evaporator receptacle 4 is evaporated and the burner is lighted, e. g. by a slow match. The flame will now heat the length of pipe 10 in the :burner 3, whereby the fuel therein is intensively heated and partly evaporated, thus forming bubbles which owing to their buoyancy will lift the liquid fuel column in front of the heating zone in the pipe it to the overflow reservoir 7, whereby the difference between the level 15 in the tank 11 and the level in the overflow reservoir 7 is easily overcome, even if the level 15 falls to a considerably lower position. The fuel in the reservoir '7 is continuously fed to the evaporation receptacle 4 through the pipe 6 and from the rec-eptable 4 to the burner 3 via the pipe 5, whereby the combustion of the fuel is continuously maintained at a uniform rate of flow.

A part of the fuel, i. e., the overflowing fuel, is re turned to the tank 11, through the return pipe 13, where it is cooled by the cooling ribs 14, so that it will not contribute to any appreciable rise in temperature of the fuel figure operates in the descending part 11, 8, 9 of the fuel supply pipe the lower part of the annular chamber of the receptacle The overflow reservoir 7 is constructed in such a way that the volume of the fuel therein, including that in the pipe 6, is always smaller than the capacity of the evapo ration body 4, so that no more than this amount of fuel can flow out from pipe 5 when the fuel supply is shut off at 16.

It is also possible, however, to close a shut-off valve or cock 17 in pipe 5. In this case, the flame will go out immediately and the evaporated fuel, being prevented from entering the burner, will act to force part of the liquid fuel column in the pipe 6 to return to.the reservoir 7, since the evaporation in the receptacle 4 continues for a certain length of time.

In order to re-start the burner, either the valve 16 or the valve 17 will be re-opened and the small amount of fuel left in the evaporation reservoir 4 is evoprated and lighted.

The fuel feeding system according to the present invention proved to be particularly suitable for the supply of burners with light liquid fuels, because the evaporating point of such fuels is within a temperature range readily obtainable in the combustion chamber without damaging the pipe 10. Suitably the heated portion of the pipe or riser is located at a lower level thereof, and preferably at the lowest part of the ascending leg of the U- pipe system 9, 10, so as to assure that the bubbles of evaporating fuel cannot penetrate the liquid fuel column, i. e., rather they act like the piston of a pump to raise the column of liquid fuel above them.

Thus, the fuel from the tank 11 is supplied to the evaporation receptacle 4 and fed from there to the burner 3 without the use of complicated devices, such as pressure-sensitive elements, etc., heretofore employed. An additional advantage of the arrangement according to the invention resides in that it assures a safe operation if the burner flame should accidentally be extinguished, for example, by a sudden intense air current in the chimney 2. in such cases, the continued discharge of fuel vapors from the burner nozzle into the combustion chamber has, heretofore, been a serious fire and explosion hazard, due to the possibility of re-igniting of accumulated fuel vapors by contact with hot parts of the burner. Such conditions are positively prevented in the operation of a the arrangement according to the invention, because the fuel is supplied to the burner only to the extent that it is burnt. In case of accidental extinguishing of the burner flame, the lifting action of the liquid fuel in the pipe or riser 10 is almost immediately interrupted, so that no fuel will be fed to the overflow reservoir 7 which is of limited capacity. As a result of this, only a small amount of fuel can flow from the reservoir 7 to the evaporation receptable 4 after the supply of fuel to this reservoir 7 is interrupted. This small amount of fuel is no hazard, inasmuch as a part thereof remains in the evaporation receptable 4- in liquid condition after the flame has gone out.

While the invention has been described in detail with respect to a now preferred example and embodiment of the invention it will be understood by those skilled in the art after understanding the invention that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefor to cover all such changes and modifications in the appended claims.

We claim:

l. An arrangement for feeding and burning liquid fuel, comprising a furnace having a combustion chamber, a combined vaporizer and burner associated with said chamber and being adapted to evaporate said liquid fuel and burn it, a tank for said liquid fuel being disposed higher than said combined vaporizer and burner, conduit means between said tank and said combined vaporizer and burner, said conduit means including a generally U-shaped pipe having a descending leg and an ascending leg connected to said descending leg, the free end of the latter being connected to said fuel tank at its lower part, at least a portion of said ascending leg of said U-shaped pipe being within said combustion chamber, the free end of said ascending-leg ending in an outlet above the top of said fuel tank, and descending conduit means connecting said outlet to said combined vaporizer and burner, whereby said fuel in said ascending leg is at least partially evaporated due to heating in said combustion chamber and the evaporation causes the fuel to ascend to said outlet from where it is discharged into said descending conduit means leading to said combined vaporizer and burner.

2. An arrangement for feeding and burning liquid fuel according to claim 1, wherein a valve means for shutting off the liquid fuel supply is provided at the connection between said free end of said descending leg and said fuel tank.

3. Anarrangement forfeeding and burning liquid fuel, comprising a furnace having a combustion chamber, a burner associated with said chamber, a vaporizer at said burner and adaptedto evaporate said liquid fuel, means to connect said vaporizer to said burner to feed said evaporated fuel thereto, a tank for said liquid fuel being disposed higher than said vaporizer, conduit means between said tank and said vaporizer, said conduit means including a generally U-shaped pipe having a descending leg and an ascending leg connected to said descending leg, the freeend of the latter being connected to said fuel tank close to its bottom, at least the lower portion of said ascending leg of said U-shaped pipe being within said combustion chamber, the free end of said ascending leg ending in an outlet above the top of said fuel tank, and descending conduit means connecting said outlet to said vaporizer, whereby said fuel in said ascending leg is at least partially evaporated due to heating in said combustion chamber and the evaporation causes the fuel to ascend to said outlet from where it is discharged into said descending conduit means leading to said vaporizer.

4. An arrangement for feeding and burning liquid fuel according to claim 3, wherein an overflow chamber is provided interconnecting said outlet of said ascending leg and said descending conduit means, and wherein a return flow conduit connects said overflow chamber to said fuel tank, said outlet and said return flow conduit ending in said overflow chamber at the same level and above the connection of said return flow conduit with said overflow chamber.

5. An arrangement for feeding and burning liquid fuel according to claim 4, wherein a cooling means is inserted in said return flow conduit.

6. An arrangement for feeding and burning liquid fuel according to claim 4, wherein said overflow chamber has a fuel capacity which is smaller than that of said vaporizer.

7. An arrangement for feeding and burning liquid fuel according to claim 4, wherein the upper part of said overflow chamber is connected to an exhaust pipe for the gases collecting above the liquid fuel in said overflow chamber.

8. An arrangement for feeding and burning liquid fuel, comprising a furnace having a combustion chamber, a burner associated with said chamber, a vaporizer at said burner and adapted to evaporate said liquid fuel, means to connect said vaporizer to said burner to feed said evaporated fuel thereto, a tank for said liquid fuel being disposed higher than said vaporizer, conduit means between said tank and said vaporizer, said conduit means including a generally U-shapcd pipe having a descending leg and an ascending leg connected to said descending leg, the free end of the latter being connected to said fuel tank close to its bottom, at least the lower portion of said ascending leg of said Ushaped pipe passing through said combustion chamber at a level below the connection of said free end with said fuel tank, the free end of said ascending leg ending in an outlet above the top of said fuel tank, and descending conduit means connecting said outlet to said vaporizer, whereby said fuel in said ascending leg is at least partially evaporated due to heating in said combustion chamber and the evaporation causes the fuel to ascend to said outlet from References Cited in the file of this patent where it is discharged into said descending conduit means leading to said vaporizer. UNITED STATES PATENTS 9. An arrangement for feeding and burning liquid fuel 477,872 Roberts June 28, 1892 according to claim 8, wherein a valve means for shut- 5 1,567,815 Bavenor Dec. 29, 1925 ting off the supply of evaporated fuel is inserted in said 1,629,722 Michaud May 24, 1927 connecting means between said vaporizer and said 2,587,078 Wollner Feb. 26, 1952 burner.