US2117968A - Gas burner - Google Patents

Description

May 17, 1938. o. LUTHERER GAS BURNER Filed ApIil 25, 1934 INVENTOR GAS OTTO LUTHERER Patented May 17, 1938` APATENT oFFicE GAS BURNER.

Otto Lutherer, Cleveland, Ohio, assigner to The North American Manufacturing Company, i Cleveland, Ohio, a corporation of Ohio l Application April 25, 1934,` Serial No. 722,339

l Claims.

This invention relates to burners for gaseous fuels wherein combustion is characterized by a luminous flame. The combustible constituents typically em- 5 ployed in such va burner-are usually the available natural or artificial gas hereinafter referred to as gas or merely fuel, and a suitable supporter of combustion therefor, usually air, and hereinafter so referred to; although it will be appreciated that 1o other gaseous hydrocarbon fuel and suitable supporter of combustion therefor'may be employed, In some industrial burner applications it has recently been considered desirable` thatthe flame have a luminous characteristic, by which some of its heat may be distributed to the work by radiation. Heretofore in the art it has .been considered `necessary to this end, that very close regulation be maintained, of relativey velocities of the combustible constituents and of the rate and manner 2o of their commingling, it being considered essential that combustion beat a slow rate, confined to a `limited zone of contact between adjacent confluent streams of gas and air.`

Objects of this invention are to produce means by which luminous combustion may be had without critical sensitivity of such operating conditions.

Luminous combustion is obtained according to this invention, by cracking or breaking down of ther gas by heat, without combustion, to liberate minute particles of free carbon, which subsequently, during combustion, become incandescent; the invention being based upon the theory that heat only ls required to crack the gas, so that its subsequent incandescence is not primarily a function of time or of its manner of joining the air of combustion, and hence the invention `does not contemplate'theusual attempt to prevent .or delay or particularly control intermin- 40 gling of the air with the gas, the latter having been cracked.

More particular objects of the invention are therefore to provide for the liberation of free carbon particles within the burner itself and in amount easily controlled by control of the amount the gas is preheated. The burner `contemplated by the invention includes means for so preheating the gas, by auxiliary combustion, independent of the primary combustion accomplished by "the burner, the auxiliary combustion being either of an independent fuel or of a portion of the gas Y with which the burner is supplied.

The exact nature of this invention together with further objects and advantages thereof will be apparent from the following description taken in connection with the accompanying drawing which is, generally, a typical longitudinal section through a characteristic embodiment thereof.

With reference now to the drawing,r `I represents the wall of an industrialfurnace, having a 5 burner inlet opening 2, and the usual cover plate or jacket 3.

Secured to the outer end of the openingZ as by the bolts 4. is a burner generally indicated at 5, The burner includes a central tubularduct or 10 pipe 6, the outer end of which is adapted for connection with a gas supply as indicated, The duct ls preferably longitudinally adjustable relative to other parts of the burner and, as shown for the purpose, is secured in slidably adjusted positions 15 by a set screw 1 in the closure 8 in which the duct bears. 'I'he burner includes a casing providing cavity 9 about the duct 6 having the lat'eralconnection IIi for a source of `air supply. A baille II extending into the cavity 9 about the duct 6 in 20 the zone of the connection I0 forms an annular passage I2 about the duct and provides a uniform air ow along the passage I2 from the air inlet. About the passage I2 is the jacket indicated providing an annular chamber I3 having connection 25 as at I4 for a source of auxiliary fuel; and a number of circumferentially spaced openings I5 allow .flow of fuel from the chamber I3 to the passage I2 and about the duct 6.

It will be appreciated that all the burner'parts r3o described, with the exception of the supply connections referred to, may be of circular section and coaxially arranged as indicated; and that the opening v2 in the furnace wall is formed as indicated, to provide acon'tinuation of the discharge opening of the burner; but other sectional forms of the parts may be preferable in specific applications.

In yoperation of the burner air is supplied through the connection I0, the fuel gas through 40 the duct 6 and an auxiliary gaseous fuel through the connection Il, all as indicated bythe legends on the drawing, each under sufficient pressure to accomplish its feeding, and preferably each under suitable volumetric control as by the usual valve 45 means.

'I'he air entering the chamber 9 is evenly distributedl by the baille II so that it flows through the passage I2 as a stream of annular section along and about the duct 6, thence lthrough the 50 furnace wall opening 2, and ultimately into the furnace. The auxiliary fuel is distributed by the annular chamber I3 and finds its way into the passage I2 through the openings I5, forming a ring of 55 jets about the duct l. Combustion of this auxiliary fuel at these jets heats the ductv l to a high temperature, controlled by the amount of auxiliary fuel fed to the jets. 'Ihe amount of air flowing through the passage l2 is very much in excess of that necessary to support complete combustion of the auxiliary fuel at the jets. `In fact it may in some cases be desirable that a certain amount of air be included with the auxiliary fuel supplied to its inlet connection i4.A At any rate, there issues from the passage l2 into the opening 2, suilicient air to support complete combustion of gas discharged by the mouth 6a of the duct, including however the products of combustion of the jets at the openings I5.

vThe gas flowing through the duct 6 is cracked or-broken down by the temperature towhich the duct is raised bythe auxiliary fuel jets, so that the gas leaving the mouth 6a of the duct, acting as a nozzle, includes, entrained, the minute carbon particles liberated by the cracking process. As the gas leaves the duct and mingles with the air its combustion takes place, the combustion of the entrained carbon particles being accompanied by their incandescence so that the flame has a luminous character.

While this luminous combustion might theoretically commence close to the end 8a of the gas duct, it will be relatively slow, continuing through the opening 2 in the furnace wall and therebeyond, most of the flame extending into the interior of the furnace, as will be appreciated by one familiar with the art, and the hollow of the opening 2 acting primarily as a mixing chamber. By longitudinal adjustment of the nozzle or gas duct 6 its mouth 6a may be so positioned that the flame will be substantially whollywithin the furnace cavity. By the arrangement described, the greater the amount of heat' supplied by the auxiliary fuel, which heat is easily controlled by control of the auxiliary fuel itself, the higher will be the temperature to which the gas in the duct 6 will be heated and the greater will be the degree ofits cracking.. Thus the degree of carbon liberation can be controlled independent of the furnace temperature.

Also, the proper functioning of the burner is substantiallyindependent of gas and air velocities through the burner and of the rate of mix- Ving ofthe gas and airafter they have passed from the burner into the furnace.

' What I claim is:

1. In a gas burner of the class described, pipe meansiarranged to deliver fuel at one end, casing means arranged to provide a chamber about said pipe means, with an end opening in the direction of flow in the pipe means and with its opposite end closed, said casing having a lateral air inlet adjacent its closed end, annular baille means arranged opposite said inlet. with an end opening in the direction of the closed casing end but short of the latter. said pipe means being mounted upon said casing end, and means including an opening in said casing means for feeding auxiliary fuel to said chamber about said pipe means.

2. In a gas burner of the class described, a straight pipe arranged to deliver gas at one end, casing means arranged to provide a chamber coaxially disposed about said pipe, with an end opening in the direction of flow in the pipe and with its opposite end closed, means for feeding auxiliary fuel to said chamber distributed about said pipe, and means for feeding air to said chamber adjacent the closed end of the latter, in suiilcient amount to supportcombustion of both of said fuels, and baille means arranged coaxially within said chamber to distribute said air uniformlynbout saidpipe before contact of said air with either of said fuels.

3. In a gas burner of the class described, a straight pipe arranged to'deliver gas at one end, casing means arranged to provide a coaxial chamber about said pipe, with van open end adjacent the mouth of said pipe and with its opposite end closed, means for feeding auxiliary fuel to said chamber intermediate the ends thereof and distributed about said pipe, said casing means having a lateral air inlet adjacent its closed end and baille means coaxially arranged opposite said inlet to provide distribution of air about said pipe before contact with said auxiliary fuel.

4. In a gas burner of the class described, a straight pipe arranged to deliver gas at one end, casing means arranged to provide a coaxial chamber about said pipe, with an end opening in the direction of flow in the pipe and with its op posite end closed,saidy casing having a lateral air inlet adjacent its closed end, baille means arranged opposite said inlet to direct infiowing air toward the closed end of said chamber, thence toward the mouth of said pipe, and means for feeding auxiliary fuel to said chamber about said pipe, between said pipe mouth and said baille means. y

5. Agas burner of the class described comprising a, straight main fuel pipe having an open mouth, casing means arrangedA to provide a chamber coaxial with said pipe, with an end opening in the direction of flow in the pipe and with its opposite end closed about the pipe, said pipe extending into said chamber, said casing means having a lateralair inlet opening and baffle means arranged to direct incoming air toward said closed chamber end and about said pipe, and means for feeding auxiliary fuel about said pipe within s'aid chamber.

OTTO LUTI-IERER.

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