US 2762656 A
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Description (OCR text may contain errors)
Sept. 11, 1956 R. P. FRASER 2,762,656
LIQUID ATOMIZER Original Filed 001;. 11, 1951 Inventor REGINALD P. FRASER I KM Attorneys LIQUID ATOMIZER Reginald 1. Fraser, Kingston Hill, England Original application October 11, 1951, Serial No. 250,890. Divided and this application October 28, 1955, Serial No. 543,572
Claims priority, application Great Britain October '17, 1950 s *(Ilaims. or. 299-120 This invention relates to liquid atomisers and has particular reference to so-called two-fluid or blast atomisers. The present application is a division from my United States patent application Serial No. 250,890 filed October 11, 1951, which relates to a fuel combustion chamber in which the liquid atomiser of the present application is used for atomising liquid fuel within the chamber.
The atomiser of the present invention is of the kind in which liquid is swirled in a swirling chamber and issued divergently from a central exit orifice as a hollow cone of spray, the cone angle of which may vary considerably, and in particular may be as wide-angled as, say, 120.
The atomiser is also formed with an annular exit or jet passage surrounding the liquid exit orifice for enabling air or steam or the like to issue as a hollow converging cone of gaseous medium, this stream being preferably Whirled prior to its issue from the annular orifice in order to form a convergent divergent cylindrical vortex.
The object of the present invention is to provide certain improvements in atomisers of the above stated kind as will now be described with reference to the accompanying drawing.
The atomiser illustrated comprises the tubular outer body or shell 21 with terminal cap 22, and an inner hollow body member 23 having an externally dish-shaped head piece 24 co-operating at its periphery with an internally conical lip 25 on the forward end of the cap 22 to form a gap 26 of predetermined size so that air or steam supplied to the shell at its rear end will emerge as a conically converging stream from the said gap 26. Inclined vanes 27 on the cylindrical wall of the hollow body member 23 serve to impart a whirling motion to the stream of air or steam before it reaches the said gap.
Inside the front end of the hollow body member 23 is fitted a liquid spray forming member or swirl spray pressure nozzle 28. This spray forming member 28 is externally hemi-spherical at its forward end to seat against a conical formation 29 behind the dish shaped head piece 24. The said spray member is hollow to constitute a swirl chamber and is provided with an exit orifice 30 for register with a central opening 31 through the head piece 24 and is formed with tangentially cut inlet slots 32 in its skirt portion which is seated on the front end of a tubular stem or plug 33 so that liquid fuel entering the interior of the said member will become swirled before nited States Patent 2,762,656 Patented Sept. 11, 1956 ice escaping from the orifice 30. The contact between the cone surface of the head piece 24 and the hemi-spherical surface of the spray member 28 is linear, being substantially a circle, and thereby provides a particularly eflicient form of seating for the liquid spray forming member 28. Such spray forming members may differ in orifice size and are readily interchangeable.
Liquid fuel reaches the inlet slots 32 of the spray forming member 28 from a supply pipe 34 connected axially to the base of the hollow body member. From the pipe 34 the liquid fuel passes into the interior of the body member 23 and along the interior of the aforesaid stem 33 at the rear of the spray member 28 and out through radial holes 35 into the annular space 36 existing between the forward end of the hollow body member 23 and the spray member 28 and thence to the said inlet slots 32. It will therefore be understood that the liquid fuel emerges as a swirling hollow conical or tulip-like spray from the exit orifice 30 and opening 31 while whirling air or steam emerges convergingly from the annular gap 26.
Atomisers constructed as above described are particularly useful in liquid fuel combustion chambers as described and illustrated in the specification and drawings of my parent patent application Serial No. 250,890.
What I claim is:
1. A liquid atomiser comprising a liquid spray-forming member having an internal swirl chamber and an exit orifice, a hollow body member having a centrally apertured circular front end piece behind which the said spray forming member is housed, an end cap surrounding the said end piece in spaced relation thereto and thereby providing an annular orifice for the issue of a gaseous medium, and a plug member for maintaining the front end of the said spray forming member pressed against the internal surface of the said front end piece of the hollow body member, the abutting surfaces of the said end piece and the said spray-forming member being such as to constitute a substantially circular linear contact.
2. An atomiser according to claim 1, in which the said abutting surfaces are respectively a hollow conical surface and a hemi-spherical surface.
3. An atomiser according to claim 1, in which the front surface of the front end piece of the said hollow body member is of dished formation.
4. A liquid atomiser according to claim 1, including means for whirling the gaseous medium before it issues from the said annular exit orifice.
5. A liquid atomiser according to claim 1, wherein the shape of the said annular exit orifice for the issue of the gaseous medium is such as to impose a forwardly converging shape on the issuing gaseous stream.
References Cited in the file of this patent FOREIGN PATENTS 536,224 Great Britain May 7 1941 664,676 Great Britain Ian. 9, 1952 703,914 Great Britain June 21, 1954 862,599 Germany Jan. 12, 1953