US2044694A - Nozzle - Google Patents

Description

Patented June 16, 1936 UNITED STATES PATENT OFFICE This invention relates to an improvement in atomizing nozzles and has particular reference to nozzles for oil burners where the oil is fed to the nozzle under pressure. In recent years in.

5 the oil burning industry consumers have'come to be more critical as to the amount of oil consumed than in the beginning of the industry when oil burners were considered somewhat oi. a novelty and luxury, and for this reason nozzle l requirements are much stricter than in the past and thereis now a demand for atomizing nozzles of very small capacity as compared with those used heretofore.

It has been difficult up to the time of the pres '15 ent invention to meet these demands satisfactorily. One reason for this is that when the demand is for nozzles of very small capacity, such as one gallon or less, difllculty is experienced with producing commercially suflloiently small .20 ejection orifices for such capacity, it being the practice heretofore to reduce the diameter 01 the ejection orifice in reducing the capacity of the nozzle. It will be appreciated, however, that there are limits to which the orifice and oil pas- 25 sages may be reduced. Exceeding that limit stoppage of the oil passages is bound to occur, as

foreign matter and bits of heavy oil are not excluded entirely although filters and screening devices are employed. Furthermore, production 30 on a commercial basis is excluded.

I have provided by the present invention a construction whereby thecapa'city of the nozzle may be reduced to the minimum desired in practice, that is to say, one gallon or less per hour capacity, without reduction in the diameter of the ejection orifice and oil passages to the dimensions where stoppage will occur. Briefly, I am able to produce a one gallon capacity nozzle, for example, with an ejection orifice of the same diameter as has heretofore been employed in con nection with the making of orifices of two gallon capacity.-

In atomizing nozzles of the pressure type it is customary to equip the nozzle body with a discharge orifice, and within the nozzle body to provide a member equipped with an ejection orifice and a swirl chamber, the ejection orifice and swirl chamber being aligned with each other and with the discharge orifice of the nozzle. Oil under pressure is fed to this swirl chamber past a distributor head seated upon the swirl chamber member, this distributor headbeing equipped with tangential slots through which the oil is forced to the swirl chamber where it is given a swirling or rotary motion about the axes of the swirl chemher and ejection orifice, the oil discharging therefrom through the ejection orifice and the discharge orifice of the nozzle.

As above mentioned, it has been customary in the past in reducing the capacity or the nozzle to reduce the diameter of the ejection orifice thereby restricting'the oil which can be discharged in a given time at a given pressure from the nozzle. Care must be exercised, however, that the parts be so dimensioned that the oil will be properly atomized and discharged from the nozzle in a true cone. If the ejection' orifice be reduced in diameter to too-great an extent then stoppage will occur.

To fully comprehend my invention it must be understood that the control of the oil from the time it leaves the distributor head until it is discharged from the ejection orifice makes the invention possible. It must be understood also that the control is such that a cone shaped, finely atomized spray will result. Briefly, the ejection orifice and swirl chamber are so proportioned relatively to the slots of the distributor head and with respect to each other that with an ejection orifice of a diameter which under present practicewould pass two gallons of oil per hour at a given pressure instead oi. half that amount, the oil movement is so. controlled due to the length of the ejection orifice in conjunction with the centrifugal action set up in the oil due to its swirling motion, the oil in its passage through'the ejection orifice being held to the walls of the ejection orifice in' a tube-like form, that the oil will be sufiiciently retarded in its flow to reduce the nozzle capacity to the point desired and the ofl is discharged from the nozzle in the desired cone-shaped, finely atomized spray.

In the accompanying drawing I have illustrated two embodiments of my invention:

Fig. 1 is a sectional elevational view of a nozzle 40 embodying my invention;.

Fig. 2 is an end view of the nozzle distributor or distributor head; and Fig. 3 is a view similar'to Fig. 1 0! another embodiment of my invention.

Referring to the drawing in detail and first I of all to Figs. 1and 2, I designates the nozzle body which is provided at its end with a discharge orifice 2. Within this nozzle body and adjacent the discharge orifice 2 is a member 3. This memher is provided with a swirl chamber 4 and ejection orifice l. v

The upper face of the member 3 is recessed as indicated at 6. This recess terminates at the inner end of the swirl chamber 4. The lower end of the ejection orifice is slightly flared as shown at 'l where it meets the discharge orifice 2 of the nozzle body. The ejection orifice i and swirl chamber 4 are aligned with each other and with the discharge orifice 2 of the nozzle body.

Within the nozzle body and in superimposed of the recessed face 5 of the member 3 makes a much smaller angle with the horizontal than the steeper side walls of the swirl chamber 4. In other words, while the recess 6 terminates at the entrance end of the swirl chamber 4, the recess does not merge into the swirl chamber, and inasmuch as the fiat portion or apex H of the frustocone 9 terminates short of the entrance end of the swirl chamber, a space or chamber I2 is provided at the ends of the tangential slots Ill and intermediate the flattened end I l of the distributor l and the inner end of the swirl chamber 4.

The distributor 8 is held seated in the recessed face 8 of the member 3 by a screw stem I 3 which is screwed into the nozzle body, this stem being provided with a longitudinal and cross bore I 4 whereby oil is supplied to the nozzle under pressure.

In this embodiment of my invention the distributor 8 and screw stem I3 are separate members which permits the distributor 8 to shift slightly laterally in seating, thereby insuring good contact or seating of the distributor in the recessed face 8 of the member 3. This essential for best results in small capacity nozzles.

I have found by hundreds of tests that nozzles, if constructed as above described, can be produced commercially with the necessary amuracy and uniformity without detrimental reduction in the diameter of the ejection orifice 5, the same .diameter orifice being employed, for example, for nozzles from two gallon capacity per hour down to one gallon or less.

It will be appreciated that if the'problem were merely to provide a nozzle-employing the tangential slots ill, swirl chamber 4 and ejection orifice 5 through which a given quantity of oil is to be discharged per hour, disregarding the fact that stoppage will occur, and without regard to proper atomization, the desired results could be obtained by properly dimensioning the slots ill. However, proper atomization without stoppage is just as essential as proper capacity. I have found that, with these small capacity nozzles, by properly dimensioning the slots l0 and'by lengthening the ejection orifice so that the, oil passing there-1' through from the swirl chamber is caused by centrifugal force to hug the wall of the ejection orifice so as to assume a tube-like form, the oil will be suiliciently retarded to allow but one gallon, for example, per hour at a given pressure to be passed through an orifice the diameter of which has heretofore been employed for two gallon nozzles, without danger of plugging and stoppage, and the oil will discharge from the nozzle in the desired cone-shaped, finely atomized spray.

Under my invention, the length of the ejection orifice I is materially greater than its diameter, and the smaller the capacity of the nozzle the greater the length of the ejection orifice as compared to its diameter. In Fig. 1 of the drawing of this application the length of the ejection orifice is about three times its diameter which is an acceptable ratio for nozzles of one gallon per hour capacity, for example.

In the embodiment of my invention, as illustrated in Fig. 3, in which corresponding parts are given the same reference characters as in Fig. l. I have illustrated a nozzle having a greater capacity than the nozzle of Fig. 1, and it will be seen from an inspection of this drawing that while the diameter of the ejection orifice is the same, its length has been considerably reduced, as compared with the showing in Fig. 1.

From all of the foregoing it will be seen that the present invention prc vides a construction particularly well adapted for use in small capacity nozzles, wherein it'is unnecessary to reduce the diameter of the ejection orifice to a dimension where stoppage is, likely to occur, the desired restriction in the oil fiow being obtained by lengthening the ejection orifice until the increased friction thus obtained as the swirling oil is caused by centrifugal action to hug the wall of the ejection chamber is sufiicient to reduce the ejection orifice capacity to the point desired.

What I claim is:

1. An atomizing nozzle comprising in combination a nozzle body provided with a discharge orifice, a member within said nozzle body provided with an ejection orifice and a swirl chamber, said ejection orifice being positioned adjacent said discharge orifice, the said discharge orifice, ejection orifice and swirl chamber being in alignment, the upper face of said member being recessed, a distributor within said nozzle body having a tapered face corresponding in form to said recessed face and cooperating therewith, the angle which said recessed face makes with the horizontal being less than the angle made with the horizontal by the side walls of the said swirl chamber, tangentially extending oil slots in the tapered face of said distributor, said distributor terminating short of the adjacent end of said swirl chamber, thereby providing for causing oil fed under pressure through said slots to swirl about the axes of the swirl chamber and ejection orifice, said ejection orifice being so restricted relatively to the swirl chamber that the oil from the swirl chamber will pass through the ejection orifice in tubular form.

2. An atomizing nozzle comprising in combination a nozzle body provided with a discharge orifice, a member within said nozzle body provided with an ejection orifice and a swirl chamber, said ejection orifice being adjacent said discharge orifice, the said discharge orifice, ejection orifice and swirl chamber being in alignment, said swirl chamber flaring outwardly from the ejection orifice, the upper face of said member being recessed, the angle which said recessed face makes with the horizontal being smaller than the angle made by the side walls of said swirl chamber with the horizontal, a distributor within said nozzle body having a tapered face corresponding in form to said recessed face and seating thereon, said distributor terminating short of the adjacent end of said swirl chamber, tangential slots in said tapered face for the passage under pressure of oil to be atomized, said swirl chamber and ejection orifice being so proportioned that swirling oil from the swirl chamber will be forced in tubular form through the ejection orifice, and a screw stem in the nozzle body for seating the distributor on said recessed face, said stem being detached from the distributor.

3. An atomizing nozzle comprising in combination a nozzle body provided with a discharge orifice, a member within said nozzle body provided with an ejection orifice and a swirl chamber, said ejection orifice being of materially greater length than its diameter and being disposed adjacent said discharge orifiee, the said discharge orifice, ejection orifice and swirl chamber being in alignment, the upper, face of said member being recessed, the angle which said recessed face makes with the horizontal being smaller than the angle made with the horizontal by the side walls 01' said swirl chamber, a distributor within said nozzle body having a i'rusto-' conical end seating on said recessed face, the sides or said trusto-cone being tangentially slotted for the passage oi! oil under pressure, said distributor terminating short of the adjacent end of said swirl chamber thereby to provide a. chamber between the apex of the frusto-cone and the swirl chamber with which said tangential slots are in constant communication, said ejection orifice being so restricted relatively to the swirl chamber that the swirling oil from the swirl chamber is retarded in its flow and caused to pass through the

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