US2276961A - Burner - Google Patents

Description

March 17, 1942.

D. P; GRAHAM ET AL BURNER 2 Sheets-Sheet 2 Filed Feb. 18, 1941 BY ?1 01 61? (T Vrm Patented Mar. 17, 1942 BURNER David P, Graham, Flushing, N. Y., and Robert C. Vroom, Montclain N. J., assignors to Peabody Engineering Corporation, New York, N. Y., a corporation' of New York Application February 18, 1941, Serial No. ?79,422

9 Claims.

This invention relates to fuel hurners and more particularly to rotary fuel burnerstof the reaction type wherein fuel issuing from a reaction rotor drives the air fan.

The invention is particularly applicable to industrial gas or oil burners, although it may be applied to various burners which are adapted to use a fuel capable of' furnishing the necessary reaction forces for driving the rotor.

An object of the invention is to provide a novel and improved burner of the above type in which the fuel is prevented from passing through the rotor bearings.

Another object is to .provide a burner of the above type in which the bearings are cooled by the fuel supplied to the burner.

Another object is to provide a burner of the above type having novel and improved .combinations of parts and details of Construction.

various other objects and advantages will become apparent as the nature of the invention is more fully disclosed.

Although the novel features which are believed to be characteristic of this invention are pointed out more particularly in the claims appended hereto, the invention itself may be better understood by referring to the following description, taken in connection with the accompanying drawings, in which a specific embodiment thereof has been set forth for purposes of illustration. i

In the drawings,

Fig. 1 is a longitudinal section, taken along the line l-l of Fig. 2 illustrating the Construction of a burner emhodying the present invention;

Fig. 2 is a section taken on the line 2' 2 of Fig. 1; V

Fig. 3 is a longitudinal section taken on the line 3-3 of Fig. 4, illustra-ting a further embodiment of the burner;

Fig. 4 is a transverse section taken on the line 4--4 of Fig. 3;

Fig. 5 is a longitudinal section taken on the line 5--5 of Fig. 6 illustrating a still further embodiment of the invention and Fig. 6 is a transverse section taken on the line 6--6 of Fig. 5.

Referring to the drawings more in detail, the invention is shown as applied to a burner for use in the burner opening of a furnace wall Il. The burner comprises a cylindrical shell !2 adapted to seat within the opening a and defining an air passage l'! through which air for combustion is supplied. The shell !2 may be provided with a fiange !3 secured against the outer 32 and 33.

In the embodiment shown, the flinger 52 is surface of the wall!! for holdingthe shell in position. A spider !4 having a hollow hub is mounted within the shell !2. The spider !4 may be adjusted longitudinally within the shell and may be held in place by set screws !6.

The hollow hub !5 is provided with an ;inner wall forming a central hearing chamber 2! and an outer wall 22 spaced from the wall 20 to form an annular fuel passage 23 which sur-, rounds the bearing chamber ZI. A housing 24 is Joined to the hub !5 by spaced ribs 25'and constitutes a forward extension of said hub. The housing 2 4 comprises forward and rear walls 26 and 2'! respectively forming an annular fuel chamber 28 which is in communication with the passage 23 through passages 29 in theribs 25. Ih the-embodiment shown, two ribs 25 are provided. It is to be understood, however, that three or more such ribs may be provided if desired. The housing 24, ribs 25 and hub !5 are shown as formed in a single casting but they maybe made as separate elements if desired. Thespace 38 between the housing 24 and the hub !5 is open to the atmosphere existing within the tube l2.

A shaft 3! is journalled for rotation in anti-` friction bearings 32 and 33 in the hearing chamber 2! and projects at both. ends from the hub !5, extending through the fuel outlet chamber 28. A fan 35 is keyed to .the rear end of the shaft 3! by a key ,36 and, is held in position by a nut 31. cup carrying hollow reaction arms is keyed to the forward end of the shaft 3! by a key!!! and is secured by a nut 42.

The reaction arms 45 are provided with apertures 46 which are spaced along the arms so as to distribute fuel .uniformly across the entire cross-sectional area of the burner opening. The

i apertures .45 are positioned' to produce rotation of the shaft 3! and associated apparatus by the reaction of the fuel issuing therefrom. A fluid seal is efiected between the walls 25 and 2'! of the housing 24 and the shaft 3! and the cup 40 'respectively by suitable means shown as labyrinth packings 4'! and 48. g

A rotating deflector 50 is securedon a shaft 3! `in the space 393 for directing radially any fuel which may pass the labyrinth packing 4.8 so as to prevent building up eddy Currents which might result in combustion of leakage gas in the space 3'0. Rotating oil flingers 5! and 52 are mounted on the shaft 3! on the outside of the bearings A reaction rotor comprising. a hollow v seated against a shoulder 53 on the shaft 3l and bears against the inner ball race 33a of the bearing 33. A spacer 54 extends between the inner ball race 33a of the bearing 33 and the inner ball race 32a of the bearing 32. The flinger 5! engages the inner ball race 32a, and a spacer 55 separates flinger 5| from the hub of the fan 35. The nut`31 accordingly serves to olamp the above mentioned elements in axial position on the shaft 3l. Inasmuch as the fan 35 is keyed to the shaft 3l, the shaft may be held against rotation thereby while thenut 31 is being tightened or loosened.

The defiector 50 is shown as seated against a shoulder 60 on the shaft 3| and a spacing member 6! extends from the deflector 50 to a central fiange 62 of the cup 40, whereby the nut 42 clamps the reaction rotor and associated elements in position on said shaft. The keyed reaction rotor serves to hold the shaft 3| against rotation while the nut 42 is adjusted.

The forward (furnace) end of the bearing chamber 2| is substantially closed by a wall 63 of the hub !5. The rear end thereof may be closed by a plate 64, which may be secured to the hub !5 by suitable means, shown as screws 65. The outer ball race 33b of the bearing 33 may be positioned against a shoulder 66 in the wall 20. The outer ball race 32b may be held in position by a retaining ring 61, thereby securing the assembly against longitudinal movement.

Fuel may be supplied to the annular fuel passage 23 through a supply pipe 61 which may be threaded into a boss 88 in the hub |5. To permit assembly of the apparatus, the shell l2 may be provided with a slot 69 to receive the pipe 61. This slot may be closed by a cover 10 which may be positioned over the shell l2 after the burner has been assembled and may be secured by suitable means, shown as screws 1l.

operation In the operation of this device, fluid fuel, such as gas or oil or atomized oil passes through the pipe 61 to the annular fuel passage 23, thence around the bearing chamber 21, through the passages 29 in the ribs 25 to the fuel supply chamber 28, thence through the hollow cup 40 to the reaction arms 45 whence it issues through the apertures 46. The reaction of the fuel issuing from these apertures serves to cause the arms 45 to rotate and thereby rotate the shaft 3! and the fan 35 attached thereto.

The fuel passing through the annular fuel passage 23 around the bearing chamber 2| serves to cool the same. The passage of air from the fan 35 over the hub |5 also assists in cooling the entire hub section. This air mixes with the fuel issuing from the apertures 48 of the reaction arms 45 to form a combustible mixture which is discharged into the furnace and burned.

Any fuel which leaks past the labyrinth packings 41 and 48 is picked up in the air stream to form a part of the combustible mixture. Inasmuch as the space 30 between the housing 24 and the bearing chamber 2l is maintained at the pressure of the passage l1 which is no higher than the pressure in the bearing chamber, there is no tendency for leakage fuel to enter the bearing chamber.

It is to be understood that suitable oil means, not shown, may be provided for lubricating the bearings in chamber 2l. In certain instances, the bearings may be packed with grease, depending upon the Construction thereof. In any event, the bearings are uncontaminated by the fuel and the-life of the apparatus is materially increased.

It is to be noted that by mounting the fan and reaction rotor at opposite ends of the shaft 3l, the rotating parts may be more readily balanced, thereby increasing the stability of operation and eliminating the tendency to vibrate, features of importance in large, industrial installations. Furthermore, either the fan or the reaction rotor maybe removed and replaced as desired for adjusting the burner for emcient operation with various types of fuel without dismantling the remainder of the apparatus.

Figs. 3 and 4 The embodiment of Figs. 3 and 4 is similar to that of Figs. 1 and 2, except that the reaction rotor is provided with a hollow shaft through which the fuel flows to the reaction arms. In this embodiment, parts similar to those of Figs. 1 and 2 have been given the same reference characters and the description thereof will not be repeated. A hollow shaft 15 is provided in place of the solid shaft 3| of Fig. 1. The fan 35 is shown as provided with a hub 16 which is threaded onto and closes the end of the shaft 15 and may be secured by a set screw 11. The reaction arms 45 are shown as attached to a hollow hub` 18, which is also threaded onto the end of the shaft 15 and may be secured by a set screw 19. The hub 18 closes the forward end of the shaft 15 and forms a fuel passage to the arms 45. The rotating defiector 50 is adapted to slide over the shaft 15 and is held in place by suitable means shown as a set screw 80.

The inner ball race 33a is shown as held against a shoulder 8| on the shaft 15. The separator 54 extends between the inner ball races 32a and 33a and a spacer 82 extends from the inner ball race 32a to the hub 16 of the fan 35. The outer ball race 322 of the bearing 32 is held in position by a flange 83 formed on a cover 84 for the hub 15, which is secured by screws 85. The cover 84 is provided with a boss 86 which has a running fit with the spacer 62 to which it is sealed by a labyrinth packing 81. A similar labyrinth packing 88 is provided for the wall 63 forming the forward end of the bearing chamber 21.

The hub |5 is shown as provided with an extension 90 forming an inlet passage which is joined to a fuel supply pipe SI. The extension 90 passes through the slot 69 in the shell l2 in a manner similar to the fuel pipe 61 of Fig. 1.

The hollow shaft 15 is provided with a plurality of apertures 94 registering with the fuel supply chamber 28 and is adapted to supply fuel from the chamber 28 to the reaction arms 45.

The operation of this device is similar to that above described, the fuel passing from the supply pipe 9! through the annular fuel passage 23 around the bearing chamber 2 I, thence through the ribs 25 to the fuel supply chamber 28. From the fuel supply chamber 28, the fuel passes through the apertures 94 to the interier of the hollow shaft 15 and thence through the hub 18 to the arms 45 of the reaction rotor, whence it issues from the apertures 46 therein, causing the entire rotor to rotate as above mentioned.

The fuel flowing through the passage 23 and the air flowing over the hub |5 serve to cool the bearing chamber 2I. Any fuel which leaks past the packings 41 and 48 is picked up by the stream of air for combustion. The bearing chamber 2! is sealed by the packings 81 and 88. Inasmuch as the space 30 is maintained at the pressure of the passage ll, there is no tendency for leakage fuel to enter the be'arin'g chamber or to flow therethrough. The bearings accordingly, as in Fig. 1, operate in an atmosphere of air and out of contact with the fuel.

F'gs. 5 and 6 In the embodiment of Figs. 5 and 6, the burner is generally similar to that shown in Figs. 3 and 4, except that the fan and reaction rotor are mounted on the same end as the hollow shaft. In this embodiment, parts similar to those previously described have been given similar reference numerals and the description thereof will not be repeated. The fan 35 is shown as ormed with a hollow hub 99 which is held against a shoulder on the hollow shaft 15 by the hub 18 of the reaction rotor, which is threaded onto the end of the shaft '15, as described in connection with Fig. 3. The hubs 18 and 99 may be Secured by set screws llll and !02 respectively. The rear end of the shaft 15 is provided with a cap !04 which engages and secures the nner ball race 32a in position. A removable cover !05 is provided for closing the rear end of the hearing chamber ZI. The cover !05 is shown as provided with a flange me, which bears against the outer ball race 32b of the hearing 32 for holding the assembly in place. may be secured by suitable means shown as bolts o.

A cover IIO may be attached to the hub |5 by bolts III. This cover o is spaced from the cover !05 to form a chamber il2 in communication with the annular fuel passage 23 and is provided with a boss |l3 suited to receive a fuel supply pipe IM which extends axially from the hub 15 to supply fuel to the chamber H2 at the closed end of the hearing chamber 2I.

For controlling the flow of air through the shell !2, a shield l|5 is provided which is adjustably mounted on the pipe l|4 :by means of a hub ll6 and may be held by a set screw ll'l. The shield |l5 is provided with a sight and ignition hole IIB having a cover l|9 Secured thereover as by a bolt IZIJ.

In the operation of the embodiment shown in Figs. 5 and 6, fuel supplied from the pipe l|4 passes through chamber l|2, the annular fuel supply passage 23, the passages 29 in the ribs 25, the fuel supply chamber 28, the apertures 94, the hollow shaft 15 and the hollow hub` 18 to the hollow arms 45. Flow of air for combustion is induced by the fan 35 above mentioned. The flow of air through the shell |2 is controlled by the shield 5, which may be adjusted longitudinally of the pipe IM for this purpose.

When the burner is to be disassembled, the oovers !05 and HD are removed, thereby exposing the end of the shaft 15. The reaction arms 45 and the fan 35 are removed, the flinger 50 is released and the shaft pulled out rearwardly with the bearings 32 and 33.

In this embodiment the hearing chamber ZI is permanently sealed at one end. thereby preventing any passage of leakage fuel therethrough. Inasmuch as the fuel in the space 30 is at the pressure of the passage IT, there is no tendency for the fuel to pass into the hearing chamber 2 l.

In the embodiments shown, the fuel flowing through the annular passage 23 cools the bearing chamber. In certain instances, however, this passage may be omitted and the fuel may be supplied directly to the chamber 28. The fan The cover and reaction rotor may be mounted at the same end of the shaft in the embodiments of Figs. 1 and 3 or the Construction of Fig,- 5 'may 'be used with a solid shaft as in Fig. 1 if desired.

It isto be noted that all of the above described embo'diments provide a' fuel supply chamber which is separated from the bearing` chamber by a space maintained at the pressure existing with in the tube 12 so that all tendency 'for leakage fuel to flow into the hearing chamber and contamiriate the bearings is eliminated, regardless of the pressure of the fuel in the supply chamber. The device is sturdy and dependable in Construction, efficient in operation and well *suited for commercial use.

Although certain embodiments of the invention have been shown for purposes of illustration, it is to be understood that the invention is not to be limited thereto but that various changes and modifications may be made therein as will be readly apparent to a person skilled in the art.

The invention is capable of various uses and is only to be limited in accordance with the scope of the following claims.

What is claimed is:

1. A fuel burner comprising a hollow stationary hub having a hearing chamber therein, an annular fuel supply chamber coaxial with said hearing chamber and spaced axially therefrom to provide an air space therebetween, a shaft journalled in said hearing chamber and extendins through said fuel supply chamber, an air fan to supply air for combustion mounted on said shaft, a reaction rotor driven by the fuel for combustion mounted on said shaft to drive said shaft and said fan, said reaction rotor including a hollow hub member and reaction arms having passages communicating therewith and apertures forming reaction jets, and means to supply fuel from said annular fuel supply chamber to said reaction rotor, said air space preventing the building up oi pressure in excess of that in the bearing chamber and thereby eliminating the tendency for leakage fuel to flow into said bearing chamber.

2. A fuel burner comprising a hollow stationary hub having a bearing chamber therein, an annular fuel supply chamber coaxial with said hearing chamber and spaced axially therefrom to provide an air space therebetween, a shaft journalled in said hearing chamber passing through said fuel supply chamber and extending forwardly beyond said fuel supply chamber and rearwardly beyond said hearing chamber, an air fan to supply air for combustion mounted on the rearwardly projecting end of the shaft, and a reaction rotor driven by the fuel for combustion mounted on the forwardly projecting end of said shaft to drive said shaft and said fan, said reaction rotor including a hollow hub member and reaction arms having passages communicating therewith and apertures forming reaction jets, and means to supply fuel from said annular fuel supply chamber to said reaction rotor, said air space preverting the building up of pressure in excess of that in the hearing chamber and thereby eliminating the tendency for leakage fuel to flow into said bearing chamber.

3. A fuel burner com prising a hollow stationary hub having a bearing chamber therein, an annular fuel supply chamber coaxial with said hearing chamber and spaced axially therefrom to provide an air space therebetween, a shaft journalled in said bearing chamber and extending through said fuel supply chamber, an air fan to supply air for combustion mounted on said shaft, a reaction rotor driven .by the fuel for combustion mounted on said shaft to drive said shaft and said fan, said reaction rotor comprising hollow reaction arms and a hollow cup carrying said arms, said cup being mounted on said.

shaft and having its side spaced therefrom to provide a fuel passage to said hollow arms, said cup communicatin with and efiecting a fluid seal with said annular fuel supply chamber, whereby uel is supplied from said chamber through said cup to said reaction arms, said air space preventing the building up of pressure in excess of that in th bearing chamber and thereby eliminating the tendency for leakage fuel to flow into said bearing chamber.

' 4. A fuel burner comprising a hollow stationary hub having a bearing chamber therein, an annular fuel supply chamber coaxial with said bearing chamber and spaced axially therefrom to provide an air space therebetween, a hollow shaft secured in said bearing chamber and extending through said fue] supply chamber and having a plurality of apertures formed therein in registration with said fuel supply chamber for receiving fuel therefrom, an air fan to supply air for combustion mounted on said shaft, a reaction rotor driven by the fuel for -combustion mounted on said shaft to drive said shaft and said fan, said reaction rotor comprising hollow reaction arms and a hollow hub carrying said arms, said hub being mounted on said shaft to receive fuel therefrom and to supply the same to said hollow arms, said air space preventing the building up of pressure in eXcess of that in the hearing chamber and thereby eliminating the tendency for leakage fuel to flow into said hearing chamber.

5. A burner according to claim 1 in which the hearing chamber is closed at one end to prevent passage of leakage fuel therethrough.

6. A burner according to claim 2, in which the bearing chamber is open to the atmosphere at both ends, Whereby the 'pressure therein is equalized and passage of leakage fuel therethrough is prevented.

7. A burner according to claim 1 in which the fuel supply chamber is joined to said hub by a plurality of spaced ribs.

8. In a burner according to claim 1, a plurality of ribs joining said fuel supply chamber to said hub, said hub having an annular fuel passage therein surrounding said bearng chamber, channeis in said ribs supplying fuel from said annular passage to said fuel supply chamber, and means supplyng fuel to said annular passage at a. point spaced from said ribs, whereby fuel for combustion is caused to flow around the bearing chamber for cooling purposes prior to passage to said fuel supply chamber.

9. In a burner according to claim 1, a rotating defiector mounted on said shaft in said air space between said hub and said fuel supply chamber, said deflector being adapted to prevent eddy currents of leakage fuel from building up in said space.

DAVID P. GRAHAM. ROBERT C. VROOM.

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