US2863700A - Liquid fuel nozzle - Google Patents

Description

W. A. ZIEMKE, JR

LIQUIDJUEL NOZZLE Dec. 9, 1958 2,863,700

Filed June 4, 1954 INVENTOR.

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United States Patent 9 LIQUID FUEL NOZZLE William A. Ziemke, Jr., Birmingham, Mich., assignor to Chrysler Corporation, Highland Park, Mich, a corporation of Delaware Application June 4, 1954, Seriai No. 434,440

8 Claims. (Cl. 299-140) My invention relates to a liquid fuel combustion apparatus, and to a liquid fuel control system for supplying the combustion apparatus with a controlled supply of liquid 'fuel.

More particularly my invention comprises a new and improved air atomizing liquid fuel nozzle adapted to be used with a gas turbine liquid fuel control system wherein air and fuel passage means are provided within the nozzle for accommodating the flow of liquid fuel and air, said control system incorporating a fuel-air pumping unit or the like for providing'the nozzle with a controlled supply of liquid fuel and air. I contemplate that the air within the nozzle air passage means may be utilized to break up or atomize the controlled flow of liquid fuel and to produce a readily combustible fuel distribution pattern.

I am aware of various types of air atomizing nozzles which have been available in the art and which are etfec- I tive to provide a combustible spray pattern of liquid fuel particles. However, such nozzles require fuel and air pressures of considerable magnitude, and the size and capacity of the fuel-air pumping unit associated therewith must be correspondingly large. Further, when the nozzle is used with a gas turbine fuel control system, the operating speed range throughout which adequate fuel dispersion may be obtained is undesirably narrow.

Certain of these nozzles of the prior art are provided With an internal mixing chamber within the nozzle assembly to facilitate the mixing of the air and the liquid fuel and a considerable restriction is encountered by the fuelair mixture before it is discharged into the combustion chamber associated with the nozzle. The unfavorable nozzle characteristics of these nozzles are believed to be due in part to the fact that this mixing of the fuel and air takes place internally.

I have overcome these and other disadvantages by providing a new and improved air atomizing nozzle which incorporates separate fuel and air passage means having intersecting branch portions. Air is conducted through the air passages and is effective to shear or break up a controlled flow of liquid fuel within the fuel passage means at the intersection of the above-mentioned branch portions.

According to an important feature of my present invention, the liquid fuel passage means is effective to accommodate the flow of fuel in the liquid state and the branch portions thereof are effective to conduct the liquid fuel to an external location near a terminal portion of the nozzle assembly. The branch portions of the air passage means are adapted to intersect the branch portions of the liquid fuel passage means in the vicinity of the nozzle terminal portion at a location which is exterior of the nozzle assembly. The liquid fuel i thereby atomized by the air externally of the nozzle rather than in an internal mixing chamber or in internal nozzle passages and the resulting spray or distribution pattern is comprised of fuel particles which are more finely dispersed than the corresponding pattern which might be obtained with conventional nozzles.

Patented Dec. 9, 1958 The provision of a nozzle of the type briefly described above being a primary object of my invention, another object of my invention is to provide a new and improved air atomizing liquid fuel nozzle which is simple in construction, which is inexpensive to manufacture and which is possessed of improved nozzle mixing characteristics.

Another object of my present invention is to provide a new and improved air atomizing nozzle for use with the combustion chamber of a liquid fuel combustion apparatus which is adapted to provide a completely atomized spray or distribution pattern of liquid fuel throughout a wide range of controlled variations in the density of the distribution pattern.

Another object of my invention is to provide an air atomizing nozzle of the type referred to in the preceding object which requires relatively low fuel and air pressures.

Another object of my invention is to provide an air atomizing nozzle as set forth above which includes fuel and air passage means Within the nozzle assembly, said passage means having intersecting portions disposed externally of the nozzle assembly to provide for external mixing.

In carrying forth the foregoing objects, I have provided a nozzle assembly comprising a circular central nozzle element with a plurality of axially extending grooves formed about the periphery thereof. A nozzle body portion is disposed about the grooved nozzle element and is effective to cooperate with the axial grooves to form a plurality of axially extending fuel passages. A terminal portion of the grooved nozzle element extends outwardly from the body portion. An axially extending air passage is provided within the nozzle element and it communicates with the aforementioned grooves at the externally extending terminal portion of the nozzle element through branch air passages. According to the presently disclosed embodiment, I have adapted the axial nozzle grooves to function as liquid fuel passages and I have centrally located the air passage means along the axis of the nozzle element.

The above-described embodiment of my invention is one preferred form of my present invention although it will be readily apparent that other forms of my invention may also be employed with equal success.

For the purpose'of more particularly describing the unique features of the aforementioned preferred form of my instant invention, reference will be made to the ac companying drawings wherein:

Figure 1 is a schematic representation of a gas turbine power plant assembly with which the nozzle of my instant invention is adapted to be used;

Figure 2 is substantially a longitudinal cross sectional view of one embodiment of the nozzle of my present invention; and

Figure 3 is a partial end view of the nozzle of Figure 2.

Referring first to the schematic power plant assembly view of Figure 1, a rotary compressor generally designated by numeral 216 is disposed adjacent an air intake opening 12 and is effective to compress the intake air. The pressurized intake air is then conducted through a portion 14 of a regenerator unit, this regenerator being generally designated by numeral 16. The compressed air becomes heated as it traverses through the regenerator unit and the heated air is conducted through suitable conduit structure or bafiling 17 to a burner cone 18 of a combustion chamber unit generally designated by numeral 20. The burner cone 18 may be suitably apertured to permit the entry of the compressed air to the interior of the combustion chamber unit 20.

I have generally shown the nozzle structure of my instant invention in Figure 1 and have designated the same by numeral 22, this nozzle structure being effective to supply the combustion chamber unit 20 with a supply of atomized liquid fuel. The fuel and air mixture within the carburetor chamber unit may be ignited by a suitable ignitor means 24 and the gases produced as a result of combustion are conducted through a two-stage turbine unit, the primary stage thereof being shown at 26 and an associated second stage being shown at 28. The primary stage 26 is drivably connected to the rotary compressor unit 10 by a compressor drive shaft 30.

The secondary turbine stage 28 is drivably connected, as shown, to a suitable speed reduction transmission 32 which may be drivably connected to a power absorbing means such as the road Wheels of an automotive vehicle. The combustion gases impart a driving torque to each of the turbine stages and then pass to another portion 34 of the regenerator unit 16 through a suitable conduit structure 36. A portion of the thermal energy of the hot exhaust gases passing through the regenerator portion 34 is transferred to the compressed intake air passing through the regenerator portion 14 which results in an increase in the operating etficiency of the engine. The exhaust gases are finally exhausted through a suitable exhaust passage means 37.

A fuel pumping unit is shown schematically in Figure l at 38 and a suitable pump drive means is provided at 40 for powering the pump 38, the input gear of the drive means 40 being drivably connected to the compressor drive shaft 36. A fuel supply conduit 42 extends from a fuel discharge portion of the pump unit 38 to the nozzle structure 22 and a suitable control valve means 44 may be interposed in this conduit 42 for the purpose of automatically regulating the supply of fuel to the nozzle structure 22 in response to the operating requirements of the power plant. A suitable air supply conduit 46 extends from an air discharge portion of the pump unit 38 to the nozzle structure 22.

Having thus briefly described the operating cycle of the gas turbine power plant of Figure 1, reference will now be made to the nozzle assembly view of Figure 2 wherein I have shown a substantially cylindrical nozzle element at 48 which comprises a large diameter portion 50 and a relatively smaller diameter portion 52. The large diameter portion 50 is externally threaded, as shown at 54, and is threadably received within an internally threaded opening 56 which extends axially through 1 a nozzle body portion 58. A terminal portion 60 of the nozzle element 48 is formed with a conical shape, the conical surface thereof extending to the exterior of the body portion 58, as shown at 62.

A plurality of axially extending grooves 64 are formed on the outer periphery of the large diameter portion 50 of the nozzel element 48 and by preference at least four of these grooves are provided in regularly spaced positions. The conical surface 62 of the terminal portion 60 are also grooved as shown at 66, these grooves 66 in dividually communicating with the axially extending grooves 64. The grooves 66 are preferably formed in an offset direction, as best seen in Figure 3, although it will be readily apparent that they may also be formed so that they extend substantially in the direction of the central axis of the nozzle element 48.

The nozzle element 48 is further provided with an axially extending air passage 68 which communicates at one end thereof with the air delivery conduit 46. A suitable threaded fitting 70 may be provided for securing the end of the conduit 46 to the end of the nozzle element 48 as shown. A plurality of branch air passages is provided at 72 at the other end of the air passage 68. These branch passages 72 are adapted to extend to the conical surface 62 and to intersect the previously described grooves 66.

The body portion 53 is provided with an externally threaded end portion 74 which is threadably received within an end opening 76 of the nozzle chamber portion 78. This chamber portion 78 may be formed of any suitable shape and is effective to define an internal annular chamber 80 formed about the portion 52 of the nozzle element 48. A central end opening 82 is provided in one wall of the chamber portion 78 and is adapted to receive therein the end of nozzle portion 52. A suitable O-ring type seal may be provided, as shown at 84, for effecting a sealing engagement between the mating surfaces of the nozzle portion 52 and the opening 82. Another wall of the chamber portion 78 may be adapted to threadably receive a suitable fitting 86 through which communication with the fuel supply conduit 42 may be effected.

The body portion 58 is provided with an outwardly extending cylindrical end section 88, the terminal portion of which is inwardly flanged, as shown at 90, to partially cover a base portion of the conical surface 62. I prefer to form the body portion 58 with a hexagonal shape, as shown, although'it is apparent that many other shapes will also be suitable.

The body portion 58 defines a shoulder 92 which is adapted to engage the periphery of a circular opening on the burner cone 18 and to clamp the same against the adjacent side of the chamber portion 78 thereby securing the nozzle assembly in a fixed position.

In the operation of the presently disclosed embodiment of my invention, the fuel air pumping unit 38 is driven by the first turbine stage 26, as previously described, and is effective to supply the fuel and air passage of the nozzle structure 22 with the required supply of fuel and air. The fuel passes through the fuel delivery conduit 42 and is controlled and scheduled by the fuel control valve means 44 in response to the power plant requirements. The controlled flow of fuel is caused to enter the chamber 80 and is then forced through the fuel passages defined by the grooves 64. The fuel is directed from the grooves 64 through the grooves 66.

Air is supplied to the air passage 68 by the air delivery conduit 46 and is caused to pass through the branch air passages 72. Upon coming in contact with the liquid fuel in the grooves 66, the air shears or breaks up the liquid fuel and atomizes the same.

It has been shown by test that the external mixing obtained with the nozzle of my instant invention results in a substantially complete dispersion of the liquid fuel particles as the fuel and air pressures and the fuel flow delivery rate are varied.

The divergence of the spray pattern may be altered as desired by forming the branch passages 72 at a different angle with respect to the nozzle axis. Further, the cone angle of the conical surface 62 may be changed as desired to provide an altered pattern shape. It is not essential that the outer exposed surface of the terminal .portion 60 should be formed with a conical shape but such a construction is preferred because of the resulting simplicity in the construction.

I have further observed that complete dispersion may be more readily obtained under certain conditions if the grooves 66 are formed tangentially or in an offset direction as viewed in Figure 3. However, it is apparent that the grooves 66 may also be formed in any other direction if desired.

I contemplate that the fuel passages defined by the axial grooves 64 might also be formed internally of the nozzle element 50 if desired. Further, it is apparent that many other modifications of the presently disclosed embodiment may be made without departing from the scope of my invention as defined by the following claims.

What I claim and desire to secure by United States Letters Patent is:

1. An air atomizing nozzle comprising a nozzle body, a nozzle element received within said body, a fuel passage system located between said element and said body, said nozzle element having an endwise tapered terminal portion extending externally of said body and having grooves formed in its outer surface, said grooves being in communication with said fuel passage system adjacent the large end of said tapered portion to conduct fuel to the exterior of said body, said body extending beyond said large end and closely overlying said grooves adjacent said large end to direct fuel along said grooves, and air passage means extending Within said element and terminating in portions intersecting said grooves at locations externally of said body.

2. An air atomizing nozzle comprising a nozzle body, a nozzle element received Within said body, a fuel passage system located between said element and said body, said nozzle element having an endwise converging conical terminal portion extending externally of said body and having grooves formed in its outer conical surface, said grooves being in communication with said fuel passage system adjacent the large end of said conical surface to conduct fuel to the exterior of said body, said body extending beyond said large end and closely overlying said grooves adjacent said large end to direct fuel along said grooves, and air passage means extending within said element and terminating in portions intersecting said grooves at locations externally of said body.

3. The combination as in claim 2 wherein said fuel passage system includes a plurality of grooves extending to said grooves in said conical surface to conduct fuel thereto.

4. An air atomizing nozzle comprising a nozzle body portion, a central opening extending axially through said body portion, a substantially cylindrical nozzle element secured within said opening, a conical terminal portion on said nozzle element extending to the exterior of said body portion, axially extending passages formed in said nozzle element, a central passage formed within said nozzle element, grooves formed in the conical surface of said terminal portion communicating with said axially extending passages, branch passages providing communication between said central passage and said axially extending passages, and means for connecting said central passage and said grooves with separate delivery conduits, said branch passages intersecting said grooves at a point which is exposed to the exterior of said nozzle body.

5. The combination as set forth in claim 4 wherein said grooves are formed in the conical surface of said terminal portion in a direction which is offset from the central axis of said nozzle element.

6. The combination as set forth in claim 4 wherein said last-named means comprises a hollow casing portion, said body portion being threadably received within said casing portion, said central passage extending through said casing portion, said axially extending passages communicating with the hollow interior of said casing portion, and means for connecting the hollow interior of said casing with one of said delivery conduits.

7. The combination as set forth in claim 4 wherein said body portion is provided with an inwardly directed guide portion adjacent said terminal portion partially covering and enclosing the grooved conical surface thereof.

8. An air atomizing nozzle comprising a nozzle body portion, a central opening extending axially through said body portion, a substantially cylindrical nozzle element threadably received within said opening, a conical terminal portion on said nozzle element extending to the exterior of said body portion, axially extending passages formed in said nozzle element, a central axially extending air passage formed within said nozzle element, grooves formed in the conical surface of said terminal portion communicating with said axially extending passages, branch air passages providing communication between said central air passage and said last-mentioned passages, an air supply conduit and a fuel supply conduit respectively communicating with said central air passage and said axially extending passages, said central passage being adapted to accommodate the flow of pressurized air for atomizing liquid fuel within said axially extending passages, said branch air passages intersecting said grooves externally of said body portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,033,068 Grifliths July 16, 1912 1,799,551 Forney Apr. 7, 1931 2,090,150 Pontius Aug. 17, 1937 2,436,815 Lum Mar. 2, 1948 2,519,200 Schumann Aug. 15, 1950 2,551,276 McMahan May 1, 1951 2,575,824 Maynor Nov. 20, 1951 2,595,759 Buckland et al. May 6, 1952 2,623,786 Wille Dec. 30, 1952

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