US2323001A - Liquid spraying device for liquid fuel burners - Google Patents

Description

Patented June 29,

mourn SPRAYING nnvrca Foa mourn FUEL nUaNEas Adolf Bargeboer, The Hague, Netherlands; vested in the 'Alien Property Custodian Application net, 1939, Serial No. 278,013

- 1: Claim. (Cl. ass-12o) One object of my invention is to impr ve the efllciency of the heretofore known spraying devices of this type and to provide an apparatus which produces a very fine and evenly distributed fuel mistcomposed of minute substantially uniform globules which are produced even when extremely heavy and crude fuels are used.

Another object of my invention is to provide a liquid spraying device of the type described which may be easily manufactured and which occupies very little space.

In my U. S. Patent No. 2,079,430, there is described a spraying device in which tangential channels lead to a whirling chamber or space and are arranged at an oblique angle to the axis of said chamber, the latter being provided with a small axial spray opening and a larger axial return opening to'produce a central cavity in the liquid rotating in the whirling space, whereby the liquid emerges from said space as a rapidly rotating thin film which is broken up into a mist at the edge of the spray opening. Inthe embodiment described in my prior patent the inner surface of the rotating liquid assumes substantially the shape of a hollow double cone.

I have found that the results obtained in my prior constructions can be considerably improved if the tangential channels are disposed substantially at right angles to the axis of the whn'ling space and the spray orifice is beveled to a knife edge.

This arrangement produces a particularly fin dispersion of the liquid fuel, because the fuel is forced into the whirling space in a direction at right angles to the axis thereof without any axial component. Thus the highly accelerated spiral fuel flow which is set up occurs practically in a plane, The axial movement of the fuel liquid towards the spray orifice is brought about solely by the bevel of the latter. As a result, the rotating fuel film is forced outwardly against the knife edge of the spray orifice under a very high centrifugal force so that even very crude and viscous fuel particles arebroken up into an extremely fine mist at this edge. In the device according to the present invenion the inner surface of the rotating liquid assumes substantially the shape of a hollow cylinder.

Other advantages of the new arrangement are that the spraying device can be easily manufactured and has a reduced axial length.

The invention is illustratively exemplified in the accompanying drawing, in which Fig. 1 is an axial section through the tip of a spraying device according to the invention, and Fig. 2 is a front elevational view of the element containing the tangential channels.

In the figures, the nozzle body II is provided at its tip with a central recess l2 and with an axial bore ii, In the bottom of the recess i2 there is a ring groove H. A plurality of fuel supply channels l5 extending parallel to the axial bore l3 open into the groove H. The atomizing tip of the nozzle comprises an inner endpart l6 and an outer end part ll. A sleeve l8 clrcumferentially embraces the two end parts It and I1 and holds them together. The whole aggregate l6, l1 and II is inserted into the recess l2 of the nozzle and is held in position by a nut I! screwed .onto a screw thread provided on thenozzle head.

The inner end part It comprisesa circular metal disc provided with an annular groove 20 of approximately the same diameter as the annular groove I4 and communicating with the latter through a plurality of perforations 2|. A cylindrical central whirling space 22 provided in the surface of the disc i6 communicates with the groove 20 through a plurality of channels 25 extending in a plane at substantially right angles to the longitudinal axis of the nozzle. The channels 25 are disposed tangentially to the whirling space 22, that is the productions of the inner channel walls extend tangentially to the imaginary cylinder bounding the whirling space. The whirling space communicates with the axial bore i3 of the nozzle by means of an axial bore 24 concentric with the whirling space 22 and having a diameter smaller than the diameter of the latter. The bore 24 constitutes the return opening ofthe whirling space.

The outer end part I! of the atomizing tip comprises a metal ring element 26 having inserted therein and rigidly united therewith a metal carbide disc 21 of a diameter substantially equal to the inner diameter of theannular groove 20. The metal carbide disc 21 is provided with a central spray orifice 28 of outwardly decreasing diameter, the smallest diameter of said opening being substantially less than that of the returnbore 24. The bevelled wall 29 of the orifice 28 is disposed at an angle of less than relative to the front face of the disc 21 so nseeoor that the edge of the spiny orifice 2e ls lormecl as e knife edge Elli.

The device operates as lfollows: Fuel is forced through the channels l6, l6 and 28 into the ennuler groove 2E9 forming the fuel supply chamher and from there through the tangential channels 225 into the whirling space 22. The fuel rotating in the whirling space is olrlven into a very replol splrel motion precticeliy free of any axial component. en the fuel film rctotlne in the whirling space 22 spreads into the orifice 28, the bevelled well 22$ of the letter eiives en axial component to the movement of the fuel suficient to elect the rotating lrom the nozzle tip. However, owing to the high speed ro edge at of the sore orifice 28 with almost nn= diminished rotary sneer! enrl will thus he urged against seirl mire with a very high centrifugel force snfilclent /o tree-l; up and finely the combinetlon of a.- nozzle having whirl chamber, fuel supply channels projecting ten gentlelly of said whirl chember and in e nlene at right angles to its axis, a. well extendinget right angles to the axis of sold whirl chamber and closing the serne at the rear enol tllereel, sold entire rear well being plane except for at single central return orifice provided in said end well, sold return orifice having e diameter smaller than thet of seiol whirl chamber, and e. hollow conical portion forming the entire front wall of seicl whirl chamber enol terminetlng at its tip in a bevelled knife edge spray orifice having e, smaller diameter then return orifice.

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