US1907604A - Oxyacetylene and similar heating burner - Google Patents

Description

May 9, 1933. A. STEPHENSON i 1,907,604

OXYACETYLENE AND SIMILAR HEATING BURNER Filed Dot. 9, 1950 4 Sheets-Sheet l I@ f ff MN y@ M May 9, 1933. A. STEPHENSON 1,907,604

OXYACETYLENE AND SIMILAR HEATING BURNER Filed Oct. 9, 1930 4 Sheets-Sheet 2 es I May 9, 1933. A. sTEPHENsoN 1,907,604

OXYACETYLENE AND SIMILAR HEATING BURNER Filed Oct. 9, 1930 4 Sheets-Sheet 3 May 9, 1933;

A. sTEPHENsoN OXYACETYLENE AND SIMILAR HEATING BURNER Filed Oct. 9, 1930 4 Sheets-Sheet 4 @W BW )Mm THW Patented May 9, 1933 UNITED .STATES MTENToi-Ficavv ARTHUR STEPHENSON, F VICTORIA STATIQN HOUSE, WESTMINSTER, ENGLAND, ASSIGNOR T0 ALLENLIVERSIDGE LIMITED, OF WESTMINSTER, ENGLAND OXYACETYLENE AND SIMILAR HEATING BURNER Application led October 9, 1930, Serial No. 487,474, and in Great Britain November 26, 1929.

This invention relates to Oxy-acetylene and similar heating burners and has particular reference to large blow-pipes employed for the local heating of metal plates, shafts and other metal objects. The present improvements many however be employed in conjunction With blow-pipes of ordinary size intended for welding or in conjunction with oxyacetylene or similar burners for other uses, such as for heating refractory bodies for the purpose of illumination.

In blow-pipes or burners of the Oxy-acetylene and similar type as heretofore constructed, it has been customary to provide amixing device comprising a mixing chamber the bore of which is axially in line with the supply conduit of one of the gases, i. e., the combustible gas Whichv may, for example, be acetylene or hydrogen, or the combustion supporting gas, which may be oxygen or air. The gas that is conveyed by the said supply conduit is -under substantial pressure and the other gas may be under a smaller pressure (in Which case an injector action is obtained), or it may be under substantially the same pressure as the first mentioned gas, in which case each gas tends to persist in its path of movement. In both constructions however intimate mingling or admixture of the gases is prevented or retarded owing to the face that the gas passing from the supply conduit in line axially with the bore of the mixing chamber is in the form of a jet travelling at high velocity and forms a core or central portion of undiluted gas which is not readily penetrated by the other gas. This core of gas is surrounded by layers of gases mixed in different proportions some of which are more explosive than the Working mixture and this conduces to blow-back of the flame which may reach the supply conduit of the combustible gas with the attendant danger of explosion.

According to one feature of the present invention the mixing device has a conduit for one of the gases, which instead of terminating in line with the bore of the mixing chamber as heretofore, is so constructed as to cause the gas to pass across the path ofmovement of the other gas on its Way to the said noz zle and in this manner the two gases, which are supplied under substantial pres- K sure, arercaused to become intimately mixed Without the formation of the core or central portion of undiluted gas as mentioned above; thus the liability of blow-back of the flame is minimized. For this purpose there may be provided in the rear part 'of the mixing chamber a plug having an axial hole which is supplied with one of the gases, for example oxygen, and the front end of this plug is disposed a short distance behind a shoulder in the mixing chamber so as to leave a small space between these parts for the passage of the other gas and the said front end is soformed as to cause the first-mentioned gas to pass across the said space and thereby become intimately mixed With the other gas flowing through this space.

Another feature of the present invention relates to a burner block having several burner orifices, transverse to the longitudinal axis of the block, for the exit of the gas so as to produce a corresponding number of separate flames. In one type of such burner block the burner orifices have been formed in separate nipples fitted to the block. This construction is expensive and presents practical difficulties in manufacture due to the fact that the independent nipples have to be fixed to the block by screwing, brazing, Welding or similar methods but it has the advantage that the circulation of air around the nipples keeps them cool Which, as is Well understood, is anecessary condition to avoid melting of the metal and back-firing of the flames. In another type the burner block is constructed on the monoblock principle (i. e. the block is made in a single piece with the burner orifices formed therein) and the necessary cooling is effected by Water which is caused to circulate through the block. This construction has the advantage of being cheap and easy to manufacture but the Water cooling is not so efficient as the air cooling and it necessitates additional hose connections to the blovvpipe for supplying and taking away this portion of the present invention is to Cil devise a construction of burner block which will give the advantages of the two types referred to above without the corresponding disadvantages.

According to this feature of the present invention the burner block is made in a single piece as above mentioned with the burner oriiices formed therein and the portions of the block containing these oriiices are separated from each other by air gaps or slots formed in the block sothat in effect each burner orifice is constituted by a separate air cooled nipple which is, however, integral with the main portion of the block. Thus each burner portion is separately cooled by the current of air induced around it and a portion of the air is also induced into the base of each iiame which, as is well known, causes the flame to burn a slight distance away from the outer surface of the burner por tion and thereby assists the cooling action.

In order that the said invention may bel clearly understood and readily carried into eEect, the same will now be described more fully with reference to the accompanying drawings, in which Figure 1 is an axial section showing a blowpipe provided with one constructional form of mixing device according to the present invention and with a tip of ordinary construction,

Figures 2, 3, 4 and 5 are axial sections showing alternative constructional forms of mixing devices according to the present invention,

Figure 6 is a transverse section taken on the line 6, 6, of Figure 5,

Figure 7 is an axial section showing a modified construction of the plug forming part of the mixing device,

Figure 8 is a front elevation of Figure 7,

Figure 9 is an enlarged sectional view of the screw threads shown inFigure 7,

Figures 10 and 11 are views similar to Figures 5 and 6 showing another form of the mixing device, Figure 11 being a transverse section taken on iie line 11, l1 of Figure 10 and viewed from the left,

Figure 12 is an axial section showing still another form of mixing device,

Figure 13 is a side elevation of the plug shown in Figure 12,

Figures 14 and l5 are views similar to Figures l0 and 11 showing a modified construction, Figure 15 being a section on the line 15, 15 of Figure 14,

Figur 16 and 17 areviews similar to Figures 14 and 15 showing still another construction, Figure 17 being a section taken on the line 17, 17 of Figure 16,

Figure 18 is a side elevation showing a construction of plug extension somewhat different from that of Figure 16, 1

Figure 19 is a section showing one form of the tip,

Figure 20 is an end view of Figure 19,

Figures 2l and 22 are views similar to Figures 19 and 20 showing an alternative form of the tip,

Figures 23 and 24 are also views similar to Figures 19 and 20 showing another form of the tip,

Figure 25 is an axial section of a form of mixing device according to the present invention constructed ,for the supply of a third 2215 Figure 26 is a vertical axial section showing a form of burner block according to the present invention,

Figures 27, 28 and 29 are respectively a plan, a front elevation and a rear elevation of Figure 26,

Figure 30 is a side elevation showing another form of burner block according to the presentl invention, and f Figures 31, 32 and 33 are respectively a plan, a front elevation and a rear elevation of Figure 30.

In Figures 1 to 25 A is the mixing chamber the bore of which communicates with the tip A1 by means of a pipe A2 (Figure 1) which conveys the mixed gases to the tip, and B is the plug which4 is inserted into the rear end of the mixing chamber and which has an 1axial hole B1 for the supply of one of the gases (preferably oxygen) to the mixing chamber, the other (e. g. acetylene) being supplied by a conduit A3 formed laterally in the mixing chamber. The said mixing chamber and the said'plug constitute the mixing device. x

Referring more particularly to Figure l, the front end of the plug B is formed with a truncated. conical portion arranged a short distance behind a coned shoulder provided in the mixing chamber A so as to leave a small space between these parts. The front end of the plug is formed with small holes b which are arranged atan angle to the axis of the plug and which at their outer ends terminate on the truncated conical portion of the plug, whilst their inner ends communicate with the axial supply hole B1 of the plug. The said small holes b are arranged substantially at right angles to the truncated conical surface so that the gas issuing in jets from these. holes passes across the space between the truncated conical portion of the plug and the coned shoulder of the mixing chamber. This space is supplied with the other gas which passes thereto through an annular passage A4 provided between the vfront part of the plug and the portion of the mixing chamber in which it is disposed. It will be understood that there is no central hole in the front portion of the plug so that there can be no formation of a core or central portion of undiluted gas as in the constructions heretofore proposed.

The construction according to Figure 2 is arranged tangentially.

similar to that according to Figure 1 except that two series of small holes b are provided at different radial distances fromthe axis of the plug and the annular passage A4 is prolonged and made narrow so as to give a restrict-ed passage for the gas. This restricted passageprovides a safeguard against a flame Vpassing back into the supply conduit and receptacle for the combustible gas in the unlikely event of ay blow-back occurring despite the intimate mixture of the gases provided by this invention.

The constructions according to Figures 3 to 6 are similar to that according to Figure 2 except that instead of the truncated conical construction at the front end of the plug B there are a number of steps on to which the outer ends of the small holes b2 open. In Figure 3 the contiguous portion of the mixing chamber is coned as in Figures 1 and 2 and the small holes b are arranged radially. In the construction according to Figure 4 the small holes are also arranged radially but instead of the contiguous portion of the mixing chamber being conical as in Figure 3 it is stepped to correspond with the steps on the plug B and with a suitable space between them. The construction according to Figures 5 and 6 is similar to that of Figure 4 with the exception that the small holes b are lIn all these constructions according to Figures 3 to 6 the oxygen issuing in jets from the small holes b pass acrossV the combustible gas flowing between the front end of the plug and the contiguous portion of the mixing chamber and intimate mixture is thereby secured. In the construc-,

tion according to Figures 7 to 9 a similar result is obtained by providing the front end of the plug B with a small plug B) having a head b* with a gap between its inner surface and the front surface of the plug B. The oxygen issues through this gap and impinges upon the combustible gas as aforesaid. The oxygen reaches the gap through a passage provided betweenthe screw threads connecting the two plugs together, these screw threads being deliberately made badly fitting for this purpose as shown in Figure 9.

Figures 10-and 11 show a modified construction in which instead of the long and narrow annular passage A4 of Figures 2 to 6 a spiral passage is provided by formi-ng the outer surface of the plug B with a. screw thread or with multiple screw threads the peripheral portions of which fit tightly within a plain cylindrical bore formed in the rear portion of the mixing chamber. The combustible gas passes through the channels provided between the threads and the said bore and issues with a whirling motion across the jets of the oxygen. The said channels I prevent the flame of a possible blowback from reaching the supply conduit of the combustible gas. A similar result is obtained in the in which the screw threaded plug B fits in animperfect manner in screw threads in the rear portion of the mixing chamber so, as to provide restricted passages for the combustible gas. This result is achieved by removing the outer surface of the screw threads on the plug and in the chamber, the arrangement in this respect being similar to that of Figures 7 to 9. In the two constructions according to Figures 10 to 13 the small holes b are arranged as shown in Figure 1 but they may if desired be arranged as in any of the constructions according to Figures 2 to 6.

In any of the constructions hereinbefore described the plug can be provided with a forward extension disposed within the bore of the mixing chamber as shown in Figures 14 to 18 in which B2 represents the said extension. This extensionbreaks up any vortex in the delivery pipe, gives a greater velocity to the mixed gases and retards back-fire from the tip. In the construction according to Figures 14 and l5 this extension is in the form of a plain cylindrical part so as to leave anannular space between it and t-hc bore. In the constructions according to Figures 16 and 17 the extension is formed with longitudinal straight flutes, whilst in the construction according to Figure 18 the extension is fluted with spiral grooves or screw threads. When flutes are provided the bore in which the extension is disposed may be similarly fluted or it may be left plain.

In the constructions according to Figures 19 to 24 the extension B2 is shown as being carried up to a tip of the blow-pipe, in which case the tip may be arranged axially in line with the mixing chamber A. In Figures 19 and 20 the extension is fluted, Figures 21 and 22 show the extension as being plain, Whilst in Figures 23 and 24 the front end of the extension is formed with .a collar B2* having a circle of small holes b2* this collar fitting closely in the bore of the tip. In the latter construction the nozzle end of the tip is pro- 4 vided with additional holes b3 to give additional flame if necessary.- The se constructions produce diiferent forms of flame at the tip.

is made hollow to provide for the supply of oxygen (or combustible gas) from the conduit B1 for use when the blowpipe is being employed for heating purposes and this gas passes through small holes b in a similar man- In the construction shown by vFigure 25- ner-'to/ that previously described so as to be- Nc'ome 1ntimately mixed With the other gas p supplied from the conduit A3. Any of the 'previously described arrangement-s of the 5 small holes or forms of plug may be employed. The pipe B1* can also be used for /P the supply of air, nitrogen, acetylene, hydrogen (or other gas) or Water according to the conditions of Work. It will of course be understood that in this modification When the blow-pipe is intended for heating purposes the supply of oxygen or other gas to the pipe B1X is shut off, the latter supply being brought into operation only when it is re-' f orifices communicate With a supply-conduit C3 formed in the block and this conduit may be cylindrical as shown in Figures 30 to 33, or it may be tapered as shown in Figures 26 to E29 so as to reduce the area of the conduit towards the outer or distant end thereof. This tapering formation is to maintain the flow of gas to all the flames at a uniform velocity which considerably diminishes the tendency for the flames to become smaller to- Wards the outer or distant end of the burner block and consequently reduces the danger of the back-firing Which is mainly due to reduced velocity of the gas. Instead of the said tapered formation the conduit may be stepped in order to obtain a similar result. The most convenient Way of forming the aforesaid air slots C2, unless the burner block is of such a size as to permit of their being formed in the casting, is by milling to a suitable depth. Another method which gives slightly improved results and has the advantage of providing a uniform thickness of metal round each orifice is to form or machine the burner portions CX so that they have a circular cross section, using each orifice as the centre. These constructions ensure more perfect alignment of the multiple orifices than it is possible to obtain conveniently by any of the existing methods of fixing the separa-te nipples into the main block. Alignment is a very important factor in blow-pipe burners of this type, especially Where theyv are intended for continuous heating under mechanical control.. The burner portions U* y ,may be arranged rwith their orifices in a single plane containing the longitudinal axis of the burner block as shown in Figures 26 to 29 and in this construction the part of the block on the side carrying the burner portions may be made tapered and the part on the opposite side may also be made tapered so as to give the block a cross-sectional shape of hexagonal form. In the construction shown by Figures 30 to 33 the burner portions C are arrangedwith their orifices lying in two planes at a small angle (30 for example) to one another. In this construction, which is primarily intended for heating shafts and other circular objects, the burner portions C* may have parallel sides as shown and the aforesaid air gaps or slots may extend to, or nearly to, the main part of the block from which the said portions project. The burner portions may, if desired, be arranged With 'their orifices lying in more than tWo planes.

rlfhese constructions of burner block are particularly, but not necessarily, intended for use with a blow-pipe having any of the forms of mixing device hereinbefore described.

What I claim and desire to secure by Letters Patent of the United States is l.v In an Oxy-acetylene or similar heating burner having a tip, the combination With a mixing chamber having a bore therein, of a shoulder in said mixing chamber, a plug having a substantially conical portion disposed a short distance behind said shoulder so as to leave a small space for the passage of one of the gases therethrough, means for supplying said gas to said space, a passage i'n said plug for the supply of the other gas and means at the substantially conical portion of said plug for causing the last mentioned gas to pass across the space between it and the shoulder in the mixing chamber and thereby become intimately mixed With the gas flowing through this space.

2. In an Oxy-acetylene or similar heating burner, the combination with a mixing chamber, of a frusto-conical shoulder .in said mixing chamber, a plug having a substantially conical portion which is arranged a short distance behind said frusto-conical shoulder so as to leave a small space for the passage of one of the gasesv therethrough, means for supplying said gas to said space, a passage in said plug for the supply of the other gas and small holes arranged in said conical portion of the plug at an angle to the axis of the plug, these small holes at their outer ends terminati ng on the said conical portion Whilst their inner ends communicate With the supply passage in said plug.

In an Oxy-acetylene or similar heating burner, the combination with a mixing chamber, of a frusto-conical shoulder in said mixing chamber, a plug havfng a substantially conical formation which is arranged a short distance behind said frusto-conical shoulder so as to leave a small space for the passage of yplying sai small holes arranged substantially -at right angles to the surface" of the conical portion of the plug, these small holes at their outer ends terminating on the said conical portion whilst their inner ends communicate wlth the supply passage in said plug.

4. In an Oxy-acetylene or similar heating burner, the combination with a mixing chamber, of a frusto-conical shoulder in said mixing chamber, a plug having a substantially conical formation which is arranged a short distance behind said frusto-conical shoulder so as to leave a small space for the passage of one of the ases therethrough, means for supgas to said space, a passage in said plug for the supply of the other gas and a series of small holes arranged substantially at right angles to the surface of said conical portion of said plug, these small holes at their outer ends terminating on the said conical portion whilst their inner ends communicate with the supply passage in said plug.

5. In an Oxy-acetylene or similar heating burner, the combination with the elements claimed in claim 1, of means giving a long restricted passage between the outer surface of the plug and the inner surface of the mixing chamber for the iow of the combustible.

gas.

6. In an Oxy-acetylene or similar heating burner, the combination with the elements claimed in claim 1, of a screw thread formed A on the outer surface of the plug, the peripheral portions of said screw thread fitting tightly within a plain cylindrical bore in the rear portion of the mixing chamber so as to provide a passage of spiral formation for the flow of the combustible gas.

7. In an Oxy-acetylene or similar heating burner, the' combination with the elements claimed in claim 1, of a forward extension of the plug, this extension being disposed within the bore. of the mixing chamber.

8. In an Oxy-acetylene or similar heating burner, the combination with, the elements claimed vin claim 1, of a plain forward extension of the.y plug, this extension being disposed within the bore of the mixing chamber.

9. In an Oxy-acetylene orA similar heating burner, the combination with the elements claimed in claim 1, of a longitudinally fluted forward extension of the plug, this extension being disposed within the bore of the mixing chamber.

10. In an Oxy-acetylene or similar heating burner, the combination with the ele- 12. In an Oxy-acetylene or similar heating burner, the combination with the elements claimed in claim 1, of a forward extension of the plug, this extension being carried up to the tip of the burner, and a collar at the front end of said extension, this collar tting closely in the bore of the tip and being provided with a series of small holes passing therethrough.

13. 1n an Oxy-acetylene or similar heating burner, the combination with the elements claimed in claim 1, of means for supplying a third gas or a liquid to the burner.

14. In an Oxy-acetylene or similar heating burner, the combination with the elements claimed in claim 1, of a pipe disposed within the plug for the supply of a third gas or a liquid.

15. In an Oxy-acetylene or similar heating burner, the combination with the elements claimed in claim 1, of a helical conduit for the passage of gas formed between said plug andsaid bore.

ARTHUR STEPHENSON.

ments claimed in claim 1, of a spirally fluted forward extension of the plug, this extension being disposed within the bore of the mixing chamber.

11. In an Oxy-acetylene orrsimilar heating burner, the combination 'with the elements claimed in claim-1, of a forward extension of the plug, this extension being carried up to the tip of the burner.

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