United States Patent Petersen et al.

[ 1 June 13, 1972 ATOMIZING NOZZLE, PARTICULARLY FOR OIL-BURNERS Inventors: Jorgen Hartvig Petersen, Nordborg; Leif Viggo Sturlason, Sonderborg, both of Denmark Assignee: Danfoss A/S, Nordberg, Denmark Filed: Jan. 13, 1971 Appl. No.: 106,054

Foreign Application Priority Data [56] References Cited UNITED STATES PATENTS 2,746,801 5/1956 Curran ..239/552 X 2,484,037 10/1949 King ..239/493 Primary Examiner-M. Henson Wood, Jr. Assistant ExaminerEdwin D. Grant v AttorneyWayne B. Easton ABSTRACT The invention relates to an atomizing nozzle having a tubularly shaped housing with an outlet orifice at one end thereof. An annularly shaped member having a frustoconically shaped backing surface is adjacent the orifice. A frustoconically shaped shell member is held in position against the backing surface with a screw member having a frustoconically shaped male surface. Grooves or slots are provided in the shell member and either or both of the frustoconically shaped surfaces are cooperable with the grooves or slots to provide fluid flow passages.

Feb. I8, 1970 Germany ..P 20 07 342.1

US. Cl ..239/544, 239/590.3, 239/596 Int. Cl ..B05b 1/26 Field of Search ..239/544, 552, 553, 553.3, 568, 239/590, 590.3, 590.5, 596, 598, 601, 554, 555, 493; 138/40 PATENTEDJUN 13 1912 saw 10F ATOMIZING NOZZLE, PARTICULARLY FOR OIL- BURNERS The invention relates to an atomizing nozzle, particularly for oil-bumers and comprising passages which are formed between a nozzle cone and a corresponding backing element.

In pressure-operated atomizing nozzles, the quantity of material expelled, the form of the atomizing cone and the even distribution of the liquid in the atomizing cone depend very considerably upon the passages which are disposed directly downstream of the outlet orifice of the nozzle. It is known to form these passages by milling grooves in the nozzle cone, these grooves being covered by the backing element. This method of manufacture is however time-consuming, since several grooves, e.g. three or four, have to be machined in each nozzle cone. Since the passages are only small, even slight lack of precision leads to defective operation of the nozzle. Such lack of precision occurs for example when the milling tool is worn, when it undergoes slight changes in its lateral and vertical settings, when a burr is formed during milling, when the passages are deformed as the result of excessive surface pressure during fitting, and so on.

The object of the invention is to provide an atomizing nozzle the passages in which can be produced at considerably less expense and with a greater degree of precision.

According to the invention, this object is achieved by providing the passages in a substantially frusto-conical insertav ble shell which is clamped between the nozzle cone and the backing element.

Although an insertable sheel of this kind constitutes an additional component, since it is thin-walled however, the passages can be formed in it with great precision and without any milling operation. Despite close dimensional tolerances, a shell of this kind is particularly suitable for manufacture by mass-production methods. Since the nozzle cone can take the form of a simple turned part, the total cost of manufacture is lower than in the case of the known atomizing nozzles.

In a preferred embodiment the passages are formed by slotting the insertable shell and by covering part of the length of the slots on both sides by the nozzle cone and the backing element. In this arrangement the cross section of the passages is determined by the thickness of the shell and the width of the slots.

In another embodiment in which the shell has a somewhat greater wall thickness, the passages are formed by grooves in the shell and by covering part of their length by the nozzle cone or by the backing element.

Very great precision can also be achieved in mass production if the insertable shell is a drawn product, from which the passages are stamped out or in which they are impressed. In particularly, the insertable shell can be made of hardened steel, e.g. spring steel. Sharp edges and the like can be smoothed off by means of an electrolytic coating.

Another method, very useful in mass production operations, is that wherein the insertable shell is a sintered product.

The invention will now be described in more detail by reference to two embodiments illustrated in the drawing, in which:

FIG. 1 is a schematic longitudinal section through an atomizing nozzle according to the invention.

F IG. 2 is a perspective illustration of the insertable shell employed,

FIG. 3 is a longitudinal section through another embodiment of the atomizing nozzle, and

FIG. 4 is a perspective illustration of the used in the nozzle of FIG. 3.

Referring to FIG. 1, the atomizing nozzle has a casing 1 containing an outlet orifice 2. In the interior there is provided an annular nozzle lining 3 with a conical backing face 4. A nozzle cone 5 can be pressed against the backing face 4 with the help of a screw 6. Between the nozzle cone 5 and the backing face 4 there is clamped an insertable shell 7. This shell is made of hardened steel sheet and contains three slots 8 which are covered over part of their length by the nozzle cone 5 on the one side and the backing face 4 on the other. In this way,

passages disposed along the length of a cone are formed in a very accurate manner. The slots 8 extend as far as the endface 9 of the shell, so that the passages open towards the nozzle orifice 2.

In the present embodiment, the insertable shell is made of sheet metal. It is produced from a flat sheet metal blank by stamping and drawing. The sheet metal is then hardened and provided with an electrolytic coating. Fitting is very' simple since the shell is automatically adjusted to give the correct position by tightening the screw 6.

The casing is screwed in the usual way on to a nozzle rod, not illustrated. Oil is fed through the inlet orifice l0,passes along passages 11 in the screw 6 and into the distributing chamber 12, whence it passes along the passages 8 to the nozzle orifice 2 and from there emerges in the form of a conical atomized body 13.

In the arrangement shown in FIGS. 3 and 4, parts that are similar to those shown in FIGS. 1 and 2 are designated by the same reference numerals as those used in these latter Figures. An insertable shell 14 made of sintered material is used in the arrangement shown in FIGS. 3 and 4. Three grooves 15 are formed on the inside of this shell and these grooves run from the rear end face 16 to an orifice 17 in the front end face 18. These grooves are covered by the nozzle cone 5 and form the passages. The grooves 15 could also be on the exterior of the shell 14 and could be covered by the backing face 4.

We claim:

1. An atomizing nozzle comprising a tubularly shaped housing having a bore and an outlet orifice at one end thereof, means forming a frustoconically shaped female backing surface, a frustoconically shaped shell engaging said backing surface, a member having a frustoconically shaped male surface, said male surface being in abutting engagement with said shell, radially extending passages between said surfaces formed by said shell and at least one of said surfaces, said member having a shank portion of lesser diameter than said bore to form an insertable shell annular distributing-chamber having fluid communication.

with said passages.

2. A nozzle according to claim 1 wherein said passages have the form of slots in said shell and are formed in part by one of said male and female surfaces.

3. A nozzle according to claim 1 wherein said radially extending passages are partially defined by recessed grooves in said shell and one of said surfaces.

4. A nozzle according to claim 3 wherein said one of said surfaces is said male surface.

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