US1636464A - Liquid-fuel burner - Google Patents

Description

` axis of the swirler, the angle a being deter Vas Patented July 19, 1927.

me mms mw; Qi smears' me, @mammina BAN'NATYNE STEWART LAIDLAW, or BEECHWOOD, sKELndotLIm SCOTLAND. g

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apuestan flied Jn'y 24,19%, sentii-' 1w. 124,727, and in' areas Britain nieuwe is'zsa Figure 2 otspecificat'ionNo. 219,378

tlie ringowi'th' a conicalexit orifice', af'nd the rear surface of theisorew' Z is alsoI inl the form of a cone.

Accordingtotl invention these two'su'rr facesk bound.V a" hypeiboloidal exit oritic'e,

the generating linesot wliichy bounding surfaces are tangential cont-iniia'tionsE of the screw thread of tlie swirler. The nature of the hyperboloid is determined by the degree of pitch of the helical' grobves in the swirler'l Air'or-steam passing 'dowiiany one of the helical grooves on 'leaving the end of the swirler will have a motion in a straight line which is in a vertical transverseplane, tangential to the circular' end ofthe swirler, and which in longitudinal plane at right angles thereto, makes an angle a withthe mined by the pitch of the Grooves; for a long pitch the angle a is small and for a short pitch the angle a is large.

Vhere cl isv the diameter of the swirler and Q9 is the pitch 7l' tan oz p hence a may be found.

The hyperboloid bounding the edges of the exit orifice of the ringand the rear surface of the screw above mentioned may now be determined as follows Referring to Figure 1 of the accompanying drawings, describe two circles a and respectively representing the diameter of the swirler and the diameter of the mouth of the ring. Draw C Dzthe diameter of a. and from its centre point E set out E F making angle Z E Fra, cutting the projection of the vertical tangent to circle a in F. Draw G H parallel toC D through F. Set out other tangents to circle a from points 2, 3, 4, etc.,

`and project their extremities onto the vflame' is nearly adi-ski But unless 'they exit orices be* curved asf described above the shape of the flame is interferedV withiby eddying of the oil@1nist,=previous toignition.

lllnthis burner the fuelIv Vcan be atomizedi by either air or steam.` v v o Figure 2' is a longitudinalfsection of a burner, and Figure 3l is a's'ect"ior'1f of lav split sleeve iIi the burner. j l Y.

Referring to ll'iigii'r'etV 2,1 A' Vis' the of theburnerf t'o which is screwed?- afcasing `BV forming an outer wall of the air or steam passage and in the end of the casing B is screwed a nozzle C. To'the body A, is screwed a tube D forming the oil supply tube, on the outside of which is a heat insulating tube E which is held in position by spring tongues F.v To the end of the tube D is screwed an air swirler G in whose end is` also screwed a screw H, the co-acting surfaces of the nozzle C andthe screw H being of the form set out above. -The air or steam is supplied through a passage J controlled by a cock, and oil is supplied through the passage L controlled by needle M. The seating for needle M is preferably curved or is a circular edge in order to allow of needles of dii'erent tapers being employed.

The Spindle N of the needle M screws into the valve vbody and terminates at the heat insulated wheel O. The' spindle N is packed an inner conical surface Q, which when the "l valve is screwed homeV compresses a ring of packing R between the surface Q and ay similar coned surfaces on the valve body.

The sleeve P is secured in position by flanged `nut T which. screws on to the valve body whilst onthe sleeve is a flange which engages with a shoulder U on the spindle N, the parts being so arranged that the spindle Nl is prevented from being unscrewed too great a distance.

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It has been found that results approximatv ing to the results obtained when a sWirler and a hyperboloidal orifice are used, are obtained when the swirler is dispensedv with, that is to say, that the exit orifice is formed as above described, although as there is no act-ual swirlertheV two bounding surfaces of the orifice have as generating lines tangential continuations of an imaginary screw of the sWirler, that is to say, the bounding` surfaces are substantially geometrically similar hyperboloids determined by the required shape of the llame. For example, if a flame is produced with 45 angled grooves of the swirler, this would be approximately produced by cutting the exit orifice to curves corresponding to the 45 angle but cutting no grooves Whatever in the swirler.

What We claim is 1. A burner comprising two coaxial passages, one `for supplying oil and the other for supplying a combustion supporting agent in a helical path, and a hyperboloidal exit orifice Whose bounding surfaces bear a delinite relation to thepitch of said helical path- 2. A burner comprising two coaxial passages and a hyperboloidalexit orifice which isbounded by surfaces which are substantially similar hyperboloids.

3. A burner comprising two coaxial pussages, a svvirler having helical grooves forining screw threadsinl one of said passages,

and a hyperboloidal exit orifice, the surfaces bounding which have as generating lines tangential continuations of the screw threads of the sWirler.

Il. A burner comprising an oil supply passage, a coaxial passage adapted to supply a combustion supporting agent, a screw threaded swirler, and a hyperboloidal exit orifice,

4the surfaces bounding which have as generating lines tangential continuations of the screw thread of the swirler.

5. A burner comprising an oil supply passage, a coaxial passage adapted vt supply a combustion supporting agent, and a hyperboloidal exit orifice the bounding surfaces of Which are substantially similar hyperboloids.

Y `6. A burner comprising a body, a tubular Eme sUMMERs DREW.

ALEXANDER BANNATYNE STEWART 1.Am1.Aw.

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