US2119969A - Liquid fuel burner - Google Patents

Description

June 7, 1938.

R. M. SHERMAN LIQUID FUEL BURNER 2 sheets-sheet 1 Filed Jan.. 25, 1936 Iawenior:

June 7, 1938.

' R. M. SHERMAN LIQUID FUEL BURNER Filed Jan. 25, 1956 2 Sheets-Sheet I hm w. I

l atented June 7, 1938 v A I 4 v UN E S-PATENT OFFICE LIQUID FUEL BURNER Rallston M. Sherman, Glastonbury, Conn, as-

- signer to The Silent Glow Oil Burner Corporation; Hartford, Conn., a-corporation of Connecticut Application January 25, 1936, Serial No. 60,832 3 Claims. (c1. 158-76) This invention relates to apparatus for burning and discharged forwardly through a prolonged liquid fuel (herein referred to for descriptive purstraight tubular air conduit 21 into which the poses as oil), and deals more particularly with impeller housing merges. burners of the so-called gun type. Positioned axially within the conduit is the oil The invention has among other objects the delivery pipe 29 terminating just short of the 5 conservation of heat imparted to the combusconduit mouth in a nozzle 3|, the pipe 29 having tion chamber of such a burner, the providing of connection at its rear end to the oil supply pipe ,simple and effective means for adjusting the air 33 entering the conduit laterally. Oil is supplied supply to the burner, and means for effectively under pressure to the pipe 33 from the oil pump, directing the air from the air impeller to the the latter being fed from a main storage tank, 10 burner. not shown. The pressure maintained and the These and other objects of the invention will form of nozzle provided are such as to cause the be best understood from the following descripdischarge of oil from the nozzle, without'pretion when taken in connection with the accommixture of air, in the form of a cone-shaped spray l5 panyihg illustration of one specific embodiment of mechanically atomized oil.

thereof, while its scope will be more particularly To ignite the commingled oil and air the usual pointed out in the appended claims. sparking electrodes 35 are employed, positioned In the drawings: v in advance of the nozzle and connected each to Fig. 1 is a plan view, partly in section, showing a conductor 31, the latter being mounted in rigid, the principal working parts of a burner emb'odynon-conducting sleeves 39 of porcelain or other 20 ing one form of the invention. like insulating material, the conductors entering Fig. 2 is an elevation showing the 'air control the conduit through the bottom thereof, 'as indevice in closed position and looking from the dicated in Fig. 3. front or nozzle end of the burner; On the installation of the burner, the forward Fig. 3 is a. central, vertical section of the rear end of the conduit is entered into and sealed with- 5 part of the burner shown in Fig. 1 but on an en in the wall 4| of the furnace (Fig; 1), the open larged scale; and mouth terminating preferably substantially flush Fig. 4 is a section on the line 4-4 of Fig. 3 with the inside of the wall of the combustion looking at the air control device from the imchamber and the combustion chamber being prefpeller end of the burner. erably sealed against any substantial admission of 30 Referring to the embodiment of the invention air other than that-entering through the conduit. here submitted for illustrative purposes, the burn- In the operation of a burner of this type, when er is equipped (Figs. 1 and 3) with a rotary air the burner is stopped, as by the actuation of a impeller ll-of the so-called Slrroco type having a room thermostat with the resultant stoppage of central air intake l3. The impeller is mounted on the, motor 2| and impeller oil delivery ceases 35 a driving shaft l5 and comprises a disc I I and an and the forced draft created by the impeller stops. opposed spaced annular plate IS with interposed But, unless preventative means are provided, the connecting multiple vanes or blades.- On one combustion chamber remains open to the conside of the impeller and connectedto the driving tinuous passage of a current of cold air through I 4 shaft I5 is mounted an electric driving motor 2| fthe air conduit which, on the stoppage of the on the pp s Side the Shaft m y be burner, i's-accelerated or intensified by the draft connected to the usua o l p p (not herein through the heated chimney. This tends quickly shown) to chill the walls of the combustion chamber and e impeller is l r i housing the the heat transfer wallsof the furnace, depriving .45 upper part of which is of generally cylindrical form, having its end wall facing the motor closed resumn g 1n a large and unnecessar heat wastage. fi gg g g g gg through 33 fi For the effective conservation of suchprevious-' sa exens,an eoppose eoren wa v preferably with an air admission opening 25 1y imparted heat and ,a more efficient operation aligned with the opening in the annular plate l9 oi the fuel burning apparatus as a whole there is 5 ofthe impeller, herein provided means for s ubstantially cutting The mp 1 u t d i eccentric relation off further delivery of air from the air conduit as r to the peripheral wall f the housing d soon as the burner ceases to function and the air tates in the'direction of the arrow shown in Fig. impeller comes to s t y p t n the I u 3, the air being drawn into the central air intake walls of the combustion chamber and the furnace 5 them of the heat previously imparted thereto and finger 51 of each blade, as indicated by dotted I from the chilling effect of the otherwise cold en-. tering air.

In the illustrated embodiment of the invention, such means is in the form of an automatically acting-air valve or shutter device (indicated in Figs. 1 and 3 generally by the numeral 43) located in the air conduit itself and preferably closely ad- Jacent the air receiving end thereof between the nozzle and the impeller, such device being adapted to open automatically for the free passage of air when the impeller is operated but to .close auto matically when the impeller is stopped.

With such device means are also provided whereby the amount of air delivered by the air conduit when the burner is in operation may be predeterminately adjusted, the usual air valveor shutter at the air suction end of the impeller being unnecessary. Such device is also preferably so arranged'as to beneficially control the path of the air through the conduit.

This device (as best shown in Figs. 2, 3 and 4) comprises a series of metallic blades 45 (herein six in number) approximately flat, each blade being of generally triangular shape with an outer arcshaped edge. Each blade at the inner and outer ends of one-edge has a small corner flange 41 bent at right angles, by means of which flanges the blade is pivotally mounted on a pin or small rod 49 and on which it is held by the small ,discshaped cap piece 5| fixedly secured on the end of the pin. Each rod is fixedly secured to the sleeve 53, and projects radially therefrom, the pins being equally spaced around the periphery of the sleeve.

The sleeve 53 is fixedly secured to the rear end of the oil delivery'pipe 29.

A torsion spring 55 encircles each pin, having one end fixed to the pinand the other extending over and lying against the face of the blade piv-'- oted on such pin so that normally the blades are urged by the light pressure of the spring in'a direction causing them to assume a closed position. or that shown in Figs. 2 and 4 and in full lines in Fig. 3. They are held in this closed posi- .tion by the small stop finger 51 (Fig. 2) projecting from the lower end of the free edge of the blade which encounters and is stopped by-the pivoting pin 49 of'the next adjacent blade.

The pivoted edge of each blade extends somewhat beyond the pivoting rod 49, and 'when the blades are in closed position this extension is there overlapped by the free edge of the next adjoining blade. When in closed position the blades together provide a substantially disc-like closure, substantially fitting the inner cylindrical walls of the air conduit, as shown in Fig. 4, with a minimum of clearance left sufficient onlyto allow the subsequent opening movement of the blades. In such closed position further passage of air through the conduit is substantially cut on. Y

When the impeller is started into operation, the blades underthe pressure of the air delivered by the impeller automatically swing about their pivot points and open into some such position as isindicated by the dotted lines in Fig. 3, allowing. the free passage through the conduit of air delivered by the impeller. The amount of air so delivered, however, and the resulting capacity of the air control device are dependent upon the extent of the blade opening movement. Thismay be predetermined and the air supply for the burner definitely fixed by the simple-use of an adjustable blade stop. Herein this is provided by means of the collar 59 which is adjustably threaded on the outside of the sleeve 53 in front of the air control device and has its rear edge presented to the stop lines in Fig. 3, which finger moves forwardly away from the pivot pin 49 when the blade undergoes its opening movement. The stop collar 59 may be adjusted to any desired position lengthwise of the threaded portion of the sleeve 53 and there held fixed by a set screwor other means. This provides adjustable means whereby the opening of the blades resulting from its adjustment may be limited to any point between zero opening and maximum, so that the air supply for the burner may be preadjusted by varying the extent of blade opening. a r

The adjustable blade stop may be made accessible for ready adjustment either by providing a removable section 6| for the top of the air conduit or by splitting the entire casing of the air impeller casing so that the upper part is removable, as

described in my previously filed application, Serialregularities in the density of the air' at different pointsaround the periphery of the air conduit.

It will be observed that when the airis being delivered by the impeller, the blades in openingassume a forwardly pitched relation which tends to convert the otherwise straight-way progressive movement of the air through the conduit into a movement characterized by rotation as well as by 'progressiom'so that the rotative movement of the air thus produced becomes a true rotative movement of uniform characteristics throughout the conduit.

I While I have herein shown and described for the purposes of illustration .one specific .form' of the invention, it is to be understood that extensive deviations may be made in the form, con- 'struction and relative arrangement of' parts, all without departing from the spirit of the invention.

I,claim: 1. A liquid fuel burning apparatus having a nozzle, for the delivery of liquid fuel to a combustio'n chamber, an, air delivery conduit surrounding said nozzle for delivering air 'to said combustion chamber to be commingled with said fuel, an air impeller for forcing air through said conduit, means between said impeller and the 'mouth of said conduit. forautomatically shutting off further substantial passage of air to the combustion chamber on. the stoppage of the air impeller, the said means comprising a series of pivotally mounted blades and a plurality of 'axes extending outwardly from and arranged symmetrically about the axis of the conduit on which axes the blades are mounted, said blades normally forming a substantial closure for the conduit, and means for holding said blades closed but yieldable under. the pressure of the air discharged by the impeller to permit them to swingto an open position to permit the passage of air through the conduit.

2. A liquid fuel burning apparatushav ing' a nozzle for/the delivery of liquid fuel to a combustion chamber, an air delivery conduit surrounding said nozzle for delivering air to said combustion chamber to be commingled with said fuel, an air impeller for forcing air through the conduit, means between said impeller and the having'a central air intake. and means in said 7 conduit near the air-receiving end thereof for mouth of the conduit for imparting a rotative movement to the air passing through the conduit and for automatically shutting of! further substantial passage of air to the combustion "5 chamber on the stoppage of the air impeller, the

said means comprising aseries of pivotally mounted blades arranged around the axis of the conduit and overlapping to form normally a substantially disc-like closure for the latter, and

10' means normally moving said blades to a conduit closing position but yieldable when said blades receive the pressure of the air delivered by the impeller to permit said blades to swing to an open position in which they impart rotation to 15' air passing through the conduit.

3. A liquid fuel burning apparatus having a v nozzle for the delivery of liquid fuel to a combustion chamber, a cylindrical air delivery. conduit surrounding said nozzle for delivering air 20-t0 said combustion chamber to be commingled with said fuel, a rotary vaned ,air'impeller for forcing air through said conduit, said impeller automatically shutting/oil further substantial passage of air to thecombustion chamber through said conduit on the stoppage oi the air impeller, the said means, comprising a series-of overlapping, segmental blades and -a plurality of equally spaced, radial axes on which the blades are pivoted, ,said axes extending outwardly-from the axis of the conduit, said blades forming a means for limiting the opening-movement of the blades to predetermine'the'supply'of air deliveredby said air impeller through said conduit. v RALLSTON M. SHERMAN.

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