US1867166A - Fuel burning device - Google Patents

Description

Patented July 12, 1.932.

PIATENr. OFFICE GARNET W. Maxim, or nocKFoRD; ILLINOIS l FUEL BURNING DEVICE j naces. Various precautions have been resorted to, such as using nozzles or tubes composed of refractory material of a high ygrade or covered in part by such material. In other instances, the mixing tube or nozzle of the burner has' been partially concealed in the furnace wall to protect it from reiected heat. But in most instances, whatever the construction was, all of these burners when used with high pressure gas or air in high temperature furnaces were either unable to keep the pro,

jected mixture burning as the flame was easily blown so far off the end of 'the nozzle that ignition of the mixture failed or the burner shortly burned itself out.v My invention includes a mixing tube for use with a fue'l mixer which is satisfactorily protected from high furnace temperatures and which also is constructed so as to decrease materially the likelihood of the flame being extinguished `when the mixture is projected at high velocity.

y One of the objects of this invention is to provide a mixing tube for conducting combustible mixtures into furnaces which' is adapted to aid in the maintenance of combustion.

Another object of this invention is to provide'a fuel burning device in which a mixing tube is so disposed in a furnace wall as to protect the tube from destruction by heat and yet promote and secure efficient and continuous combustion of the mixture projected from the tube.

Another object of this invention is to provide a fuel burning device in which a mixing tube is disposed in a furnace Wall in such a manner as to protect it from radiated heat 'tion and Will-later appear.

Application iled May 14,-1927` Serial No. 191,326.

and to cause the mixture projected from it to absorb heat from the walls of the tube.

Further objects, advantages and capabilities are inherently possessed by this inven- Referring now to t e drawing, the figure discloses a mixer generally indicated as 11 into which is conducted-high pressure gas through a pipe 12, the flowv of lgas being regulated by the valve 13. A movable shutter 14 60 regulates the admission of air in a manner Well-known in this art. The high pressure gas is projected through the orifice 15 and entrains upon itself air which is drawn in past the shutter 14. l j

The mixer is secured to a fuel delivery tube 16 by means, of the threads 17 and the inner end 18 of the tube extends into a passageway 19 in the furnace wall. In order that the tube maybe rigidly securedin position, it is connected in a suitable ymanner to the plate 21, which plate is fastened to the Wall of the furnace. The inner extremity of the mixingtube is chamfered as at 22. The passageway in the furnace Wall then slightly expands. as in the portion 23 and eventually terminates at the interior wall 24 of the combustion chamber. As will be obvious to one skilled in this art this fuel burning device is applicable to many types so of furnaces and it will therefore be understood that the fragmentary portion of a combustion chamberwall 24 shown in the drawing may be a part of any one of many types of furnaces into which gaseous fuel mixtures are projected. An example of such al combustion chamber would be the ordinary rectangular chamber of a furnace lfor annealing small forgings. j

When a mixture is being proj ectedat high velocity through the mixing tube, it expands when passing through the expanding portion 18 of the tube and asit leaves the chamfered extremity 22, part of the mixture rolls off that edge in eddy currents which proceed to roll along the expanding portion 23 of the passageway in the fire brick Wall 25. Consequently, the velocity in a longitudinal direction of the gas moving in these eddy currents `will be considerably less than the velocity of 10l u less than the diameter of the part of the pass lthe flame will be greater than the general i 'longitudinal motion of the eddy currents and will enable the flame to maintain itself in these eddy currents even though it might have a tendency to be blown oil' from the central portion of the projected stream of mixture. The flame thus maintained in the eddy currents will maintain the ignition of the entire mixture and will avoid the serious consequences which sometimes result from the blowing out of the flame without shutting oi the mixer.

Not only does this appara-tus provide a means for maintainingcombustion under abnormal conditions, but it also protects the mixing tube from excessive temperature by disposing the extremity of the tube well back y from the combustion chamber within the lire sive heat.

brick wall. With this device, it is not necessary to maintain an extremely hightemperature near the end of the burner in order to obtain combustion because of the novel construction whichresides in the chamfered edge of the tube. One is enabled to keep the extremity of the mixingtube well backv from the combustion chamber to protect it from exces- By reason of the expanding taper of the tube near its extremity the mixture expands as it makes its exit'from the tube and picks up heat from the tube walls, thus reducing the temperature of the tube and prolonging its life. This is a valuable feature since it is inevitable that some heat will be conducted through the fire brick directly to the tube.

By means of the disclosed construction,

' an apparatus is provided which is well adapted to maintain combustion under normal and abnormal conditions and which is' so arranged as to promote the long life and eicient serviceabilit of the device.

It should be un erstood that the illustrated..

embodiment of the invention may be modified considerably without departing from the spirit and scope of the invention.

Having shown and described my invention,

I claim:

' 1. In combination with a combustion chamsage through which the mixture. flows after leaving the tube.

2. In combination with a combustion chamber wall having a passage therethrough a fuel delivery tube extending into and terminating in said vpassa-ge, means for projecting a stream of combustible mixture through said tube and said passage, the posterior part of the tube having a taper expanding toward its extremity, said extremity having a. cha-mfered edge for causing eddying currents of the mixture to roll more slowly along the posterior surface of the passage than the main body of the stream flows through the central portion of the passage. v

3. In combination with a Wall having a passagey therein, a fuel delivery tube extending into and terminating within said passage, and means for projecting a combustible rmixture through said tube, the extremity of the tube within the passage being chamfered toward the adjacent passa e wall to cause nart of the mixture issuing om the tube to roll oil' the end of the tube along the wall of the passa-ge in eddy currents, the passage immediately beyond lthe .end of said ltube being free of obstructions such as-might disrupt rearward propagation of flame through said eddy currents.

4. In combination with a combustion chamber wall having a passage therethrough, a Itube projecting into and terminating in the passage for delivering a fuel mixture into the chamber and having a chamfered open end curved toward the passage Wall constructed and arranged for causing part of the mixture delivered from the tube to roll along the surface of the passage in eddying currents having a general longitudinal motion slower than the velocity 'of the main stream and maintaining intimate 'contact with the mainstream alongth'e chamfered surface of said end, the passage being free frgm obstructions beyond the end of the tu e.

In witness of the foregoing I aiix my signature. l

GARNET W. MCKEE.

fuel delivery tube extending into andterminating within said passage,- means for projecting a combustible mixture through said tube, the extremity of thev tube having a -chamfered edge for producing eddy currents in the mixture 'along the wall of said passage, the internal diameter of the tube near its chamfered extremity being considerably

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