US1991418A - Burner - Google Patents

Description

Fei.l 1935 E, A. RowE Er AL BURNER Filed Marchy 14, 1952 lneniozvs `Eu ene Rowe l Perg M. Fors-fer Patentedl Feb. l9, 1935 PATENT OFFICE BURNER Eugene A. Rowe, Seattle, Wash., and Percy M. Forster, Berkeley, Calif., assignors to Standard Oil Company of California, `San Francisco, Calif., a corporation of'Delaware Application March 14, 1932, serial No, 598,688

' s claims. (ol. 15s-10s) welded objects, expanding hubs and wheels prehmin'ary to shrinking them on shafts, and Work of similar nature. It is particularly adapted for use with liquefied petroleum gas such as propane, butane, and the like, and in combinationv with a cylinder or bottle of such liquefied gas constitutes an eiliecient and readily portable heater.

An object of this invention is to provide a burner of the air induction type in which a source of compressed air is not required for efcient combustion and the productionA of intense and lc calized heat.

Another object is to provide a torch or burner in which the source of primary air 'may be controlled and adjusted to suit the conditions of gas pressure and llame size required.

Another object is to provide a torch which will direct a relatively small diameter cylinder of flame so that its disposition may be readily controlled.

A further object'is to provide a burner construction which will be simple, economical and easy to manufacture and in which 'adjustments for ame size and gas consumption may be readily made.

Various other objects and advantages will be more fully apparent from the following description and drawing which illustrate a preferred embodiment of this invention.

The customary form of torch or burner of this nature and heating capacity foruse with illuminating or natural gas under low pressure must be `provided 'with compressed air in order to .supply suiiicient oxygen for complete combustion of the gas. It is not always convenient or economical to provide a source of compressed air for a burner, particularly in small shops, or in remote localities such as logging camps, on board ships, etc.-

Because of the fact that the pressure available from natural or artificial gas mains is on the order' of a few ounces or at the most, l or 2 pounds per square inch, the construction of small socalled air-induction burners is such that they are not suitable for use withgas of higher pressure, such as the newly introduced bottled or liquefied petroleum gas. Most of these burners are of the customary Bunsen type in which the gas emerges from a small orifice or nozzle and is directed into the center of a single large diameter Venturi tube or its equivalent. -The aspirating effect of the gas is used to draw in as much air as possible through the large iiared inlet end of the Venturi tube. No provision is made for the introduction of secondary air, which has been found essential tc secure complete and efliecie'nt combustion in large torches, with high heat value gas under high pressure.

In other words, conventional burners larger than the customary laboratory type, which are of the construction suitable for natural or artificial gas of low heat value, are not adapted to be used with liquefied petroleum gas. Elaborato 4and comprehensive tests with all commercial burners available showed them to be unsuited to this fuel. Therefore, it is evident from the subjoined drawing and description that the burner of the present invention is a radical departure of the general type of air-induction burners and that its novel feature is a primary or premixing tube of very small diameter as compared with the main bodyv of the burner, in which the rapidly moving yjet of gas inspirates and mixes with the primary air for combustion. Secondary air is admitted to this mixture through holes in the outer casing of the burner and a completely balanced and intensely hot ame isproduced at the tip of the torch. The accompanying drawing shows a partial sectional view of a torch or burner embodying the essential features of this invention. v

In this drawing, 1 represents the outer tube or body of the burner, which is preferably made of y cast bronze or other material which will resist oxidation, as it may be intensely heated for about 1,/3 of its length. 'I'he tube 1 is preferably reduced to a somewhat smaller diameter at its outermost end 'as at 2, in order to contract the llame and prevent its assuming a diverging conical shape. Secondary air p orts are provided as at 3 and are preferably symmetrically arranged around the circumferenceof the tube or body 1. The rear end of the tube or -body 1 is closed as shown at 4 and constitutes a support for the brass primary airmixing tube 5 which isscrewed or brazed in place. It is essential that the tube 5 be concentric with the tube or body 1.

Two arms 6. extend from thelback of the body 1 and terminate in an annular boss or sleeve 7, which is drilled andthreaded concentric with the tube 5. Adjustably mounted within the annular boss 7 is a brass g'as supply pipe 8, -which is threaded for a portion of its length as at 9 and which extends completely through the boss 'I into the space between the arms 6. A threaded lock nut 10 is provided to secure the adjustment of the pipe 8 with respect to the boss '7.

An internally threaded brass cap 11 is mounted on the inner end of the pipe 8 and is drilled as at 12 to provide a single small diameter oriiice through which the gas ows and enters the tube aspirated may be varied as desired by loosening the lock nut 10 and screwing the threaded portion-9 of the gas supply pipe 8 in or out of the threaded boss 7, thereby changing the distance between the tip of the gas orifice cap 11 and the inlet end of the mixing tube 5. The size of the iiame and the rate of gas consumption may be altered by substituting tips having various size orifices.` If but one rate of gas combustion is desired the end of the pipe 8 may be swaged or brazed shut and an orifice drilled directly therein, care being taken to insure that it is concentric with the tube 5. The length of the tube 5 and the number and location of the secondary air ports 3, however, need not be changed for any i particular burner.

'I'he primary air mixing tube 5 is preferably supplied with slots 16 spaced around its circumference and extending back a short distance from the outlet end. Other forms of openings may serve the same purpose but forconvenience and simplicity the use of slots cut by means of a hack saw at 90 degree intervals is preferred.

It is not known exactly the theory on which these slots perform their desirable function which appears to result from a degree ofturbulence set up between the primary air gas mixture and the secondary air, but in any event it has been found that the slotted tube causes the flame to burn farther back in the outer tube or body 1 and prevents the iiame from blowing out even under materially increased gas pressures.

As an example of this invention a torch was constructed with an outer tube or body 1, which was of l/iinch thick material, 2 inches inside diameter and Sinches long, with an inner mixing tube inch inside diameter and 1% inches long, provided with 4 slots 16 approximately 11; inch wide and 1A; inch deep. Twelve secondary air ports 3 were located as follows: Two were diametrically opposite and 11A inches from the end of the burner, four were 90 apart around the circumference and 2%, inches from the end of th'e burner, four 'were similarly located 3% inches from the end of the burner, and two were diametrically opposite and 4 inches from the end of the burner.

The tip of the burner tube or body 1 was reduced to 1H inches inside diameter at2. The gasl orifice tip 11 was drilled with a `inch diameter hole and was located 1/2 inch from the face of the closure 4. With these proportions and a pressure of 20 pounds .per square inch of propane gas, approximately 4 pounds per hour of liquid propane 4were consumed. As liquefied propane weighs approximately .4.45 pounds per lgallon and 1 gallon will vaporize to approximately 38 cu. ft. of gas at atmospheric pressure and temperature, which gas has a heat value of approximately 2,500 B. t. u.s per cu. ft., a total heat output of approximately 85,000 B. t. u. per hour was obtained with perfect combustion. It was also found that a reduction in pressure to approximately 5 pounds per square inch on the propane gas supply still resulted in an apparently perfect mixture and gave a smaller but intensely hotv blue flame.

Itwill be apparent that a number of modifications and changes could be made in this arrangement without departing from the essential featurev of the invention which embraces all changes, variations, and substitutions coming within the scope of the appended claims.

We claim: a

1. In a burner for hydrocarbon gas, a cylindrical primary mixing tube of small diameter, a secondary tube surrounding the primary tube and provided with a plurality of radial secondary air ports near its outlet end, closure means for the said secondary tube maintaining the tubes in their respective positions, a bifurcated extension to said secondary tube terminating in an annular boss, an adjustable conduit secured in said boss, said conduit terminating in a closure provided with a small diameter orice and adapted to direct a jet of gas at high velocity into the primary tube thereby inspirating primary atmospheric air into saidtube with the gas.

2. In a burner for burning inflammable gas with atmospheric air, a, hollow cylindrical body closed at one end, and having ports in its cylindrical wall near its outlet end, a tube inserted in the closed end of said cylindrical body concentric therewith and providing a passage therethrough, said tube extending into said cylindrical body for a portion of the latters length and having slots in its outlet end, and means for introducing a jet of gas to said tube whereby a mixture of gas and air is drawn into said passage and burns as an axial -'fiame at the outer end of said cylindrical body.

3. A burner for hydrocarbon gas comprising a hollow cylindrical member with a closed end, an orifice in said closed end, a tube inserted in said orifice and extending into said cylindrical member, saidtube having slots through its wall adjacent its inner end, and means for directing a jet of gas into said'tube whereby a mixture of gas and air is drawn into said tube so as to burn at the open end of said cylindricalmember.

4. A burner for iniiammabie gas comprising a hollow cylindrical member with a closed end, ports in the cylindrical wall of said member, an orifice in the closed end of said member, a tube inserted in said orifice and extending into said member, said tube having slots through vits wall, a gas supply line terminating in a jet orice directed toward theorice in the said cylindrical member andin spaced relationship thereto, and means for adjusting said spaced relationship.

5. A burner comprising a hollow cylindrical member having one end closed, a substantially straight, small Vdiameter primary airmixing tube extending into the closed end of said cylindrical member, means adjacent the inlet ofv said tube for injecting a high pressure jet of air-inspirating gas therethrough, and ports through the wall of said cylindrical member adjacent the end of said'tube and adapted to admit secondary air radially to the air-gas mixture issuing from said mixing tube, the resulting mixture burning as an axial flame at the open end of said cylindrical member. .y

6. A burner for higpressure hydrocarbon gas comprising a hollow` cylindrical member with a gas through said tube, lwhereby atmospheric air closed end, an orifice insaid closed end, 'a small is drawn into said-tube and mixed with saidgas diameter tube seated in said orice and extendso as to burn at the open end of said cylindrical ing inwardly into, said cylindrical member, said member. l member provided with ports intermediate its ends, l EUGENE A. ROWE. and means for directing a jet of high pressure PERCY M. FORSTER.

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