US2094959A - Burner for liquid fuels - Google Patents

Description

Oct. 5, 1937. Y P.-PuL.|DoR| BURNER FOR LIQUID FUELS Filed Feb. 15, 1933 @dum-vo Puhdorl' INVENTOR Patented Oct. 5, 1937 UNITED s'rATlezsl PATENT; :oFFiCE BURNER FOR LIQUID FUELS Palmiro Pulidori, Florence, Italy Application February 15, 1933, Serial No. 656,784 In Italy February 27, 1932 1 Claim.

mosphere, while the opposite end of the said.

section opens towards the interior of the diffuser. The other portion of the cross-beam comprises a pipe or tube one end of which dips into a constant level reservoir, and the other 'end opens into the interior of the aforesaid diffuser. At a suitable distance from this diffuser-and always within the body-is located a second diffuser, present-` ing an external surface in the shape of a truncated cone provided with helical varies which are concentric with and contact the inner surface of' the admission cone of a third diffuser.

In the vicinity of the mouth of the third diffuser the aforesaid tube is provided with an annular passage. The liquid fuel is heated while flowing through said passage in order to be gradually conducted into the constant level reservoir and is utilized forthwith, thus preventing the circulation of heated fuel through the tanks and the piping conveying the fuel to the burner and the formation of explosive mixtures.

Upon the burner body there are provided inlets for atmospheric air which, after passing through an annular chamber formed by the interior of the cylindrical body and the exterior of the third diffuser, joins the current of gaseous mixture in a state of combustion.

The invention will be more clearly understood by referring to the following specification in conjunction With the drawing, which shows, solely by way of example, one practical embodiment of the invention.

In this drawing:

Fig. 1 shows the device diagrammatically and in vertical section; A Fig. 2 shows the same device in cross section on line A-B of Fig. 1; t

Fig. 3 shows a variation of the device shown in Figure 2;

Fig. 4 shows a perspective of the diffuser.

According to therexample shown, thedevice consists of a'reservoir a of any suitable shape, intended to be filled with liquid fuel up to a certain level which is maintained constant by wellknown means. The reservoir a is suitably xed to thetube t which constitutes the carburetter body. Through the tube b passes the air (in the direction indicated by the arrows) for the aspira.-

tion, atomization and combustion of the liquid fuel contained in the constant level reservoir a. In the interior of the tube b is arranged a cross-head beam Vc whose axis A-B coincides with a diameter of the tube b.

The crosshead beam c carries three bores;

one being longitudinal whose axis coincides with the axis X-X of the tube b; and two transverse and diametrically opposed, whose axes coincide with the 'line A-B.

Within thelongitudinal bore is arranged a diffuser d.

Into one of the vertical boresin the cross-head beam c extends a small tube e which opens at one end into the interior of the diffuser d. A

Into the diametricall'f opposite bore extends a small tube f which dips at one end -into the liquid fuel contained in the constant level reservoir a and at the other end the tube opens into the interior of the diffuser d.

At a convenient distance from the diffuser dA and co-axially therewith is arranged a second diffuser g a perspective of which is shown in Fig. 4. The diffuser is a truncated cone the base of which constitutes .the inlet. Upon the external surface of the truncated cone shaped diffuser g a number of vanes h are suitably provided integrally with the extension o f'the inlet coneof a third diffuser i. The external surface of the latter is cylindrical and integral with the tube b. The diffuser i is provided with a recess le. The elements g-h-i form an integral and compact whole rigid with the tube b.

The operation of the apparatus is as follows:

The air required for combustion ows through the tube b in the [directionA indicated by the arrows. A certain quantity of the air passes through the diffuser d and the remainder is distributed between two circuits in parallel, one being constituted by the central port of the diffuser y and the other by the empty space l. vThe' space l, whichis annular in section, is formed by the external surface of the truncated cone shapedl diffuser g and the internal surface of the inlet cone ofthe diiuser i. i

The air passing the diffuser d concurrently with the air passing through the diffuser g gives rise to three distinct phenomena: an aspiration of the fuel from the constant level reservoir a through the lsmall tube f, the atomization of the fuel due to the violent encounter between air and fuel, at right angles, and the aspiration of a certain quantity of atmospheric air drawn into the interior of the diffuser d.

The current of atmospheric air drawn into vthe interior of the diffuser d through the small tube e brings about a certain throttling of the current of air passing through the diffuser d, or a certain counter-pressure within the said diffuser.

20 y in the phenomenon of combustionw about by the air aspirated from the atmosphere A through the small tube e is proportional to the v variations in'operatlng conditions to which the. aire passing. through -the tube b is subjected and- `spacel.v Owing tothe-contour of the vanesh lobtaih'the utmost eiiiciency of the apparatus, is fulfilled throughthe air and the 'fuel being mixed as indicated below, that is, by compelling all the particles 'of air 'and of atomi'zed fuel to participate The portion of air passing through the tube b along the'pathindicated by the arrows and not passing'fthrough'the diffuser g is expressly detoured and compelled to? traverse the annular the air stream moves longitudinally with a whirling `motion with respect to:and in the direction i the'vanesi the air continues to-jmoveygyratlng aroundlthe laxis of b and along the said axis in the direction shown bythe arrows. The air encountersv at a certain' angle'the mixture of air and vatomized vfuel flowing .out of the discharge e cone of the, diffuser g, compelling it to take on a rapid whirling motion.v Although the fuel is finely atomized', inconsequence of its bulk it spreads Ainto the discharge' cone ofthe diffuser i and becomes intirnately'mix'edY (in said discharge cone) with theair flowing out of the lannular space l.

Iny the modicatlon shown in Fig. 3 the fuel drawn fouthof the constant level reservoir Va o aperture located diametrically opposite the small v a level higher than thatA of the apparatus.,

Through the small tube o the fuel ows into the V.tube e, passes through a groovel m which is cut externally around the diffuser d. The fuel is drawn out of the.groove m by the air flowing through the diffuser and through two or more the'finterior thereof The necessary pre-heatingi of the fuel is obtained `as follows:-The liquid fuel descends from a feeder-not shown in the drawing-located at passage space p where the heat developed by the combustion which takes place in the ignition chamber lq is partly transmitted through the walls of the dliluser i and the annular space r.

On leaving this annular space, the heated fuel flows through the small '.tube s into the rconstant level reservoir a.

On the periphery of the tube b and communieating with the recess Ic are provided apertures t. The fuel-air mixture issuing from the diffuser g enters the diffuser i whence it travels to the precombustion chamber q. The mixture may be ignited at this point.

The current ot gaseous mixture undergoing combustion andissuirig from the burner outow `After passing through the passages formed by "-*oh'eoking or throwing action brought nozzle draws in through the .said apertures a certain quantity of fresh atmospheric air which enters the recess k and, flowing thence through the annular space r unites with the gaseous mixture which isundergoing combustion.

`The number vof apertures tor the opening and closing of such apertures serves to regulate at will the current of fresh air drawn in from the atmosphere which, in turn limits the pre-heating of v the fuel;

Y In operation, a blower is situated at the inlet end ofthe body b, opposite the combustion chamber. "Air from the blower passing through the diffuser d, creates a suction which draws atmospheric air through e andA preheated fuel from the reservoir a through i. 'I'he air and fuel are thus forcibly intermingled in d, then follow the direction ofthe arrows into the second diffuser g and through the helical vanes h whereby a whirling motion is'imparted thereto as the air passes into the combustion chamber. At the same time -further atmospheric air is supplied to the comy bustion chamber through the Yopening t, annular chamber'k and passage r.

It should be understood that the accompanying Vdrawing shows but one example of the invention, whose constructional details may be varied without departing from the concept orfrom the characteristic features of the said invention; in fact, for instance, the annulary space r might be formed either 'by `the adequate reduction of the external ydiameter of the diffuser i in correspondence with the recess p or by always providing for the ade- A pre-carburetting burner of the character described,r -which comprises a tubular body connected to a compressed air supply, a cross beam disposed in said tube, said cross beam being pro-4 vided with a central bore forming a diffuser, 'a liquid fuel reservoir associated with said .tubular body, aconduit connectingsaid reservoir with the said bore, a second conduit 'connecting said bore with the outer atmosphere whereby the compressed air passing. through said bore will lift fuel from said reservoir through the first conduit and draw i n airthrough-'the second conduit, a quantity of air passing outside the said cross beam, a second diffuser disposed in said tubular body and a third diffuser carrying saidsecnd diffuser, said three diffusers being `disposed coaxially inside said tubular body, said second diff fuser being provided on its outside with helicoidal passage waysto impart a rotary movement to the 'fuel-air mixture issuing from the first diffuser, a

pre-combustion chamber communicating with -Pnmaorunmoan

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