US2034210A

US2034210A - Oil burner

Info

Publication number: US2034210A
Application number: US661027A
Authority: US
Inventors: Christopher A Schellens
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-03-16
Filing date: 1933-03-16
Publication date: 1936-03-17
Anticipated expiration: 1953-03-17

Description

March 17, 1936. Cl A SCHELLENS 2,@34-,210

OIL BURNER Filed March 16, 1953- 2 Sheets-Sheet 1 INVENTOR March 17, 1936. c, A. scHELLENs OIL BURNER Filed Ma'rch 16, 1933 2 Sheets-Sheet-2 INVENTOR Patented Mar. 17, 1936 UNITED STATES nino Aralar ri Application March 16,

16 Claims.

My invention relates to liquid fuel burners in which the fuel, usually oil, is atomized before burning.

The burner is of the air driven rotating atomizing cup type in which oil is atomized by being thrown from the open end of the atomizing cup. In oil burning plants of the average size, employing this type of burner as usually constructed, the blowers which supply air to the burners, and which do not form a part of this invention, operate under conditions of excessively high delivery pressure and excessively low delivery volumes. An increase in the blower delivery pressure causes a more than p-roportional increase in power consumption as well as in cost of the blower, whereas an increase in volume causes a less than proportional, and frequently insignificant, increase in power consumption and cost. It is one of the objects of my invention to secure the high rotative speed of the atomizing cup necessary for proper atomization by the employment of a larger air volume and a lower air pressure, whereby the blower which supplies air to the burner can be built at a lower cost, and requires less power for its operation.

In burners of this type as usually constructed, difculty is encountered in obtaining a uniform speed of the atomizing cup. The resistance to rotation of the rotating elements is subject to wide variation due to varying viscosity of the bearing lubricating oil, foreign matter in the bearings, and varying rates of atomization. It is a further object of my invention to provide means whereby a substantially uniform speed of rotation is obtained irrespective of the aforesaid variable r-esistance.

Another object of my invention is to generally improve the construction and operation o-f oil burners.

In the accompanying drawings which form a part of this specification:

Fig. 1 is a vertical central longitudinal section of the burner,

Fig. 2 is a developed partial section of the air turbine wheel and turbine nozzle made by a circular cylinder coaxial with the shaft axis and passing through the line A-A, Fig. l,

Fig. 3 is an elevation from the rear end, of one of the speed governor weights, and

Fig. 4 is a vertical central longitudinal section of the burner constructed in a modified form.

My invention includes an approximately cone shaped outer casing I having the air inlet connection 2, which may be used for supporting the 1933, Serial No. 651,027

(Cl. 15S- 77) burner. which we may designate for convenience as the front end, carries an atomizer air nozzle 3, through which air passes into a furnace or other combustion space, mixing with and directing the atomized fuel.

Extending through and supported at the large end of the outer casing I, I provide an inner casing 4, which sup-ports the rotating members of the burner. The front end of the said inner casing is substantially conical, and is separated from the rear end by the partition wall 5, forming the front compartment 5 and the rear compartment 'I.

A ball bearing retainer 5 is bolted or otherwise suitably joined to the partition wall 5, and serves to support the ball bearing 9. Ball bearing I9 is supported by the front end of the inner casing The small end of the outer casingA Il, and is restrained from forward motion by the inner casing front end cover II. The shaft I2 which supports the atomizing cup I3 and the air turbine wheel I4 is journalled by the'ball bearings 9 and I0.

The atomizing cup I3 is preferably secured to the shaft I2 by means of the screw thread I5 and taper t IB whereby it may be conveniently withdrawn for inspection. The atomizing cup I3 is provided with a hub Il which is integral with the shell and divides the cup into front and rear compartments I 8 and I9 respectively. The said hub is provided with a plurality of passages 2i! whereby communication is established between the front compartment I8 and the rear compartment I9. The rear end of the cupi is provided with a flangey 2i for the purpose of preventing the oil to be atomized from spilling rearwardly.

As here shown oil is led to the atomizing cup I3 through the pipe 22, which is provided at its rear end with the pipe connection 59.

At itsfront end the pipe 22 is joined by means of a'v pipe thread to the cover II, and passages 23 and z 24 are provided in the said cover for the purpose of conducting oil to the interior of the atomiz ing cup I 3.

The air turbine wheel I4 is mounted on the shaft I2 at the rear of and adjacent to the ball bearing 9, and is prevented from turning on theV 'said shaft by the key 2l. The said turbine wheel is provided with a plurality of spaced turbine buckets or vanes 29 which are shown in section in shown in section in Fig. 2.V The said turbine nozzle directs the air from the annular space between the outer casing I and the inner casing 4 against the buckets 28 an-d causes the turbine wheel I4 to rotate rapidly.

Ball bearings 9 and i3 are'lubricated by means ofthe oil ring 3! which dips into lubricating oil contained in the lower part of the forward compartment 6. The shaft is preferably tapered, the large end being adjacent to the forward ball bearing IEl whereby a film of lubricating oil impelled by centrifugal force finds its way into the forward ball bearing.

The rear compartment 'I surrounds the turbine wheel I4, an-d is provided with a cone shaped cover 32 having a central orifice 33, whereby air from the turbine is exhausted to the outside. The cover 32 is provided with bosses 34 to which is attached baiiie plate 35, which plate has the purpose of deecting and diffusing the air issuing from the said orifice.

For the purpose of controlling the speed of the rotating members of the burner I provide speed governing means including governor weights 36,

`which are -pivod on the cone shaped ends of the hardened steel pins 37, which pins are screwed or otherwise suitably fastened to the turbine Wheel I4. As shown in Fig. 3 each governor weight consists of a hardened steel base 38 to which is secured the metal cylinder 39.

The said base is provided with a semicircular recess 40 in which the end of the pin 3i pivots. The slot 4| straddles the shaft I2 and provides a guide which prevents sidewise motion of the said governor weights.

Under the inuence of centrifugal force the slotted ends of the bases 38 bear against the hardened steel bushing 42, which is guided for longitudinal motionV by the shaft I2, and which supports the governor sleeve 43, to which it is suitably attached. The rearward motion of the governor sleeve 43 due to the action of the cen- Y trifugal force of the weights 3B is resisted, and

'governor spring 44.

the said centrifugal force is balanced, by the The said spring bears against the nut 45 which is screwed to the end of the shaft. The said nut serves as a guide for the rear end of the governor sleeve 43, and, cooperating with the spring 44, and governor weights 36, secures the turbine wheel longitudinally against the ball bearing 9.

'Ihe governor sleeve 43 is provided with a flange 45 Ywhich operates to open or close the orifice 33 asthe governor weight cylinders 3S move in or out respectively. By this means the air leaving compartment I is throttled, and the air pressure Within the said compartment is raised or lowered by the action of the speed governing means aforesaid, whereby the force of the ai;n stream directed against the buckets 28 is varied as required for the maintenance of a substantiallyv constant speed of the aforesaid rotating members.

While I'secure all of the objects `of my invention bythe construction which I have described,

fand which illustrates the preferred form of my Yinvention, I may omit the automatic speed governing means as described and still secure some ofthe objects.

IY may also arrange my invention with theV the turbine buckets 28a. Cover 32a is provided with bosses 34a to which is attached the plate 35a, which serves, as before, to deflect the air stream issuing from the aforesaid orifice. Plate 35a carries a threaded boss 5I through which the threadedstem 48 passes. The stem 48 carries the orifice plate 4l and the handwheel 49. By the manipulation of the said handwheel the said orice plate is moved in a longitudinal direction and throttles the air issuing from the said orifice, thereby regulating the speed of the said atomizing cup as required.

While I have described the throttling means as arranged to throttle the air stream after passing through the turbine buckets, it is apparent that similar results would be obtained if the air which passes through the turbine buckets were throttled before passing therethrough, and I wish to have this feature of my invention construed broadly.

How the aforesaid objects and advantages are secured will now appear. Air at a substantially constant pressure, supplied by a blower or other means not forming a part of this invention, enters the burner at the air connection 2. Part of the said air flows through the turbine nozzle 30 and impinges on the buckets 28 of the air turbine wheel I4, causing it to rotate rapidly, the said rotation being transmitted to the atomizing cup I3. Oil is fed by means not forming a part of this invention to the pipe connection 50, through pipe 22, and cover I I, and subsequently flo-ws into the atomizing cup I3, from the open mouth of which it is ejected by centrifugal force in a nely divided state.

In burners of this type as usually constructed the air first passes through the air turbine and subsequently through the air nozzle. The air turbine and the atomizer nozzle may be regarded as operating in series with reference to the air fl'ow. In a burner constructed in accordance with my invention, on the other hand, the air turbine and the atomizer nozzle are arranged in parallel. It is apparent that in the above described usual arrangement the 'pressure of the air which must be supplied to the-burner is the sum of the pressure drop through the turbine, including its nozzle, and the pressure drop throughy the atomizing nozzle.

In a burner constructed in accordance with invention, on the other hand, the pressure of the air which must be supplied to the burner `must be equal to the larger of the two aforementioned pressure drops. In the operation of Y oil burners under the usual conditions it is found that the pressure drop through the atomizer nozzle is greatly in excess of the pressure drop taking place in the turbine propelling elements, namely the turbine nozzle and buckets, provided the said turbine elements are constructed efnciently. The volume of air supplied to the burner, on the other hand, is greater tha-n in the case of a burner of the usual construction. My'

' form a part of my invention is to utilize the eX- cess pressure drop available for driving the turbine as a reserve to provide for the resistance to rotation, caused by the atomization of large oil iiows, and by increased bearing friction due to foreign matter in the bearings and excessive viscosity of the bearing lubricating oil. Thus, under normal conditions the pressure drop available for driving the turbine is reduced, either by the manually operated air throttling means as shown in Fig. 4, or, automatically, by the centrifugal speed governing means as described. Under conditions of unusual resistance to rotation the throttling action is reduced, and more of the available pressure drop is applied to the driving of the turbine. In this way I obtain a constant speed of the atomizing cup.

If, as an example, we have reference to a burner of a specific rating, in which a pressure drop of 8 inches water column is required through the atomizer nozzle, and a pressure drop of 4 inches water column is required to drive the turbine at the proper speed of rotation, it is apparent that in a burner of the usual construction air at a pressure of l2 inches water column must be supplied to the burner. Furthermore, under 'conditions of unusual resistance to rotation, the

speed of the atomizing cup decreases.

On the other hand, in a burner constructed in accordance with my invention, and having reference to the abovementioned example, air at a pressure of 8 inches water column is satisfactory for the operation of the burner. Furthermore a pressure drop of 8 inches water column is available for driving the turbine, which provides for a reserve of 4 inches water column, whereby the necessary rotative speed of the atomizing cup is maintained under conditions of the foresaid unusual resistances to rotation.

The structure of my invention may be otherwise modified without departing from the spirit thereof.

I claim:

1. In a liquid fuel burner the combination of a rotatably mounted fuel atomizing member, means for conducting fuel to the interior thereof, air actuated means arranged for driving said member, means for conducting air to said atomizing member and said air actuated means, whereby a portion of said air is conducted exclusively so as to mix with and direct fuel atomized by said fuel atomizing member, and another portion of said air is conducted exclusively so as to actuate said air actuated means, and means responsive to the speed of rotation of said atomizing member for regulating the speed thereof.

2. In a liquid fuel burner the combination of a rotatably mounted fuel atomizing member, means for conducting fuel to the interior thereof, air actuated means arranged for driving said member, including turbine buckets, a turbine nozzle cooperating with said buckets, means for conducting air to' said atomizing member and said turbine nozzle whereby a portion of said air is conducted exclusively so as to mix with and direct fuel atomized by said fuel atomizing member, and another portion of said air is conducted exclusively to said turbine nozzle and actuates said air actuated means, throttling means arranged t0 control the flow of air through said turbine nozzle, by throttling said air subsequent to its actuating. said air actuated means and a centrifugal speed governor cooperating with said throttling means whereby the speed of rotation of said atomizing member is maintained substantially constant.

3. In a liquid fuel burner the combination of a rotatably mounted fuel atomizing member, means for conducting fuelV to the interior thereof', air actuated means arranged for driving said member including turbine buckets, a turbine nozzle cooperating with said buckets, means for conducting air to said atomizing member and said tubine nozzle whereby a portion of said air is conducted exclusively so as to mix with and direct fuel atomized by said fuel atomizing member, and another portion of said air is conducted exclusively to said turbine nozzle and actuates said air actuated means, and means adapted to manual operation for throttling the air which passes through said turbine nozzle subsequent to its actuating said air actuated means, whereby the speed of rotation of said atomizing member is manually controlled.

4. In a liquid fuel burner the combination of a rotatably mounted fuel atomizing member, air actuated means driving said member, a casing enclosing said air actuated means and provided with an orifice whereby air is discharged therefrom after actuating said air -actuated means, and throttling means cooperating with said orifice whereby air discharged therethrough isthrottled and the speed of said member is controlled.

5. In a liquid fuel burner the combination of a rotatably mounted fuel atomizing member, an air actuated turbine driving said member, a casing enclosing said turbine provided with an orice whereby air discharged from said turbine escapes from said casing, and throttling means cooperating with said orifice whereby said air is throttled, said throttling means including a centrifugal speed governor responsive to the speed of said turbine.

6. In a liquid fuel burner the combination of a casing, a shaft mounted for rotation, a fuelv atomizing member mounted on one end of said shaft, an air actuated turbine mounted for driving said shaft on the other end thereof, a plurality of bearings mounting said shaft in said casing, and means exterior to said shaft for conducting fuel to said fuel atomizing member, said bearings being located between said atomizing member and said turbine.

'7. In a liquid fuel burner of the kind described the combination of a fuel atomizing cup, means for conducting fuel to the interior thereof, a compressed air actuated turbine driving said cup, and means responsive to the speed of rotation of said cup whereby said speed is regulated.

8. In a liquid fuel burner the combination of a member rotatable to atomize fuel exclusively by centrifugal projection therefrom, compressed air actuated means rotating said member, and means regulating the speed of said member responsive to the speed of rotation thereof.

9. In a liquid fuel burner the combination of a compressed air actuated member rotatable to atomize fuel exclusively by centrifugal projection therefrom, and means responsive to speed changes in the rotation of said member for maintaining said speed substantially constant including a centrifugal governor.

10. In a liquid fuel burner the combination of an atomizing member mounted for rotation, an air actuated turbine mounted for driving said member, a casing surrounding said turbine and provided with an exhaust orifice, turbine actuating air supply means discharging into said casing, and a centrifugal speed governor responsive to the speed of said turbine, and cooperating with said orifice to throttle the actuating air exhausted from said turbine, said. atomizing member, said turbine, said governor, and' said'oriflce being coaxially disposed. Y

11. In a liquid :fuel burner the combination of aturbine, a fuel atomizing cup rotated by said turbine, a casing enclosing said turbine provided with a turbine exhaust orifice, and aV centrifugal speed governor cooperating With said orifice to maintain a substantially constant speed of rotation of said cup. Y l

Y12. In a liquid fuel burner the combination of a rotatably mounted fuel atomizing cup, an air actuated turbine rotating said cup, a turbine driving nozzle, a casing enclosing said turbine provided with an exhaust orifice, an air nozzle discharging adjacent to, and directing the atomized fuel as it leaves said cup, branched air conducting means conducting air under pressure from a common source to said turbineV driving nozzle and said fuel directing nozzle, and a centrifugal speed governorV cooperating With-said orifice to throttle the air passing through said turbine to maintain the speed of said atomizing cup substantially constant.

13. In a liquid fuel burner the combination of a fuel atomizing member mounted for rotation, means for conducting fuel thereto, an air actuated'turbine member including buckets, mounted in driving relation to said member, an air nozzle discharging adjacent to, and directing the atomized fuel as it leavessaid atomizing member, an enclosure surrounding said turbine member provided with an orifice communicating with the atmosphere, branched air conducting means whereof one branch conducts exclusively driving air to flow through said turbine member, into said enclosure, and through said orifice in succession, and another branch conducts exclusively fuel directing air to said Vair nozzle, and air throttling means cooperating with said orifice to throttle the air issuing therefrom.

14. In aiiquia fuei burner the combination of Y flow through said air actuated means in driving relation thereto, into said casing, and through said orifice in succession, and another branch conducts exclusively fuel directing air to the fuel atomized'` by said atomizing member, and throttling means including a centrifugal speed governor responsive to the speed of said air actuated means, cooperating with said orifice to throttle said driving air. Y

15. In a liquid fuel burner the combination of a fuel atomizing member rotatable to atomize fuel exclusively by centrifugal projection therefrom, an air nozzle discharging adjacent to, and directing the atomized fuel as it leaves said member, an air turbine wheel driving said member, a turbine nozzle conducting driving air to said turbine, and means for conducting air to said air nozzle and said turbine nozzle at one and the same pressure.

16.V In a liquid fuel burner the combination of a fuel atomizing member rotatable to atomize .Y fuel exclusively by centrifugal projection therefrom, an air nozzle discharging adjacent to, and directing the atomized fuel as it leaves said member, air actuated means driving said member, and branched air conducting means for conducting air under pressure from a single source to said nozzle for directing said fuel, and to said air actuated means for the actuation thereof.

CHRISTOPHER A. SCHELLENS.