вход по аккаунту


Патент USA US2108819

код для вставки
Feb. 22, 1938.
w. J. JAcoBssoN
» 2,108,819.
Filed Aug. s1, 1932 ' -
4 Sheets-Sheet 1
Feb. 22,
Filed Aug. 31, v1932
4 Sheets-Sheet 2
l 1t.
Feb. 22, 1938.
» 2,108,819
Filed Aug..I s1, 1932
¿Sheets-sheet 3 "
Feb. 22, 1938.
' w. J. JAcoBssoN
Filed Aug. 3‘1, 1952
Ä 4 Sheets-Sheet 4
2,108,819 '
Patented Feb. '22, 193s4
linneo srATEs PATENT
Wilgot ‘.ll. .ïacobssom Buiiialo, N. Y., assigner, by
mesne assignments, to tïlnion Carbide andl @ar
'bon Corporation, a corporation ci New Yorba
Applicationdngust 3l, i932, Serial No. wißt@
ß malins. (Gi. läd-“WAH
rearwardly from the discharge end of the mixer
My invention relates to blowpipes adapted to
nozzle to a minimum distance from the end of
utilize oxygen and a combustible gas for pro
ducing a heating flame. The invention relates
particularly to the construction of the gas con
said nozzle so that said portion of said passages
is free from constrictions adapted to substan
tially retard the backward ilow of the gas there- ß
in from the mixing tube throat and by propor
it duits for preventing ila hbacksin the blowpipe.
When a blowpipe isf/‘functioning properly the
tioning the length and volume of said portion of .
, iiame produced by the stream of combustible gas
said gas passages in accordance with the pres
' issuing from the end of a blowpipe nozzle is sep
- surein the mixing tube throat produced by back- `
arated from the discharge orifice Ain the nozzle
10 kby an unburned portion of the gas stream.
ñres and also in accordance with the consumption 10
of the acetylene by the blowpipe.
the propagation of the ilame towards the orifice
The above and other objects will be more
is greater than the’vielocity of the- gas stream, clearly understood from the following descrip
the flame travels bac‘ward along the unburned ~tion and accompanying drawings, in which
portion of the gas st eam y,and recedes into the
Flg. I is a top view of a blowpipe disclosing one l.
l5 vcombustible gas mixt rev passage. The momen
embodiment of my invention.
taryrecession of the 1 a’me into the combustible
Fig. II is a longitudinal cross-section of the _
mixture passage lis kn n asa backilre and this blowpipe along the line II-II in Fig. I;
_ phenomenon 1s usuallyt> accompanied by a sharp
Figs. HI, IV, V, and VI are enlarged cross
explosion. If the llame continues to burn with
sections of the blowpipe taken on the lines III-III 20l
90 in the combustible gas Í ture passages this phe
nomenon is known asY ilashback which pro.
duces a sizzling noise wit
_to VI--VI respectively in Fig. I;
Fig. VII is an enlarged sectional view taken
the blowpipe. Un
on the .line VII-VII in Fig. II.
der a given set of conditiol s the direct ratio‘ot
the number of backiires. to t e number of flash
rear end views of a modification of the blowpipe 25
»5 backs is known as the flashback resistance of a
shown in Figs. I to VII.
Fig. X is a longitudinal view of the blowpipe
showing some .of- the elements in section along
When a ilashback occurs it is necessary to cut
off at least one of the llame supporting vgases
the line X-X in Fig. VIII. '
to extinguish the flashback/name. During the
ilame is rellghted and adjusted the blowpipe is
Figs. XI to XIIIare cross-sectional views along 30
the lines XI to XIII respectively in Fig. X.
Figs. XIV and XV- are respectively sectional
rendered inoperative.
views of the valve body on the lines XIV-_XIV
- 30 period of the flashback and'up untilthe time the
used for welding, the strength of> the' welîi is del
and XV-XV as shown in Fig. IX.
eteriously affected due to the cooling of the weld
Figs. VIII and IX are respectively topand
Fig. XVI is a diagrammatic illustration of my 35
d_uring the inoperative period and also due I'to the
,subsequent reheating-of the weld. If the blow
pipe is being used for` cutting, the cut may be
invention in its general aspects.
My invention is illustrated herein in reference
to metal cutting blowpipes, .that is, blowpipes
lost or made ragged as a result ofthe iiame being
utilizing a preheating iiame and a highly oxi~
dizing stream of gas for removing metal.
blowpipe disclosed in the modiiìcation shown in
In any event, time> and _gas are
40 wasted during the inoperative period oi the blow
Figs. I to VII comprises a handle I having- a
rear valve body 2 and a forward valve body 3
Heretofore it has been proposed to extinguish
the backfiring ñame by means of baffles or other
constrictions placed in the gas passages. Such
45 devices offer a resistance to the normal vforward
flow of the gases and are therefore objection
An object of my invention is to increase -the
flashback resistance of a blowpipe without in
50 creasing the resistance to the ilow of the gases
through the blowpipe passages.
rIfhe preferredv means of . accomplishing the
foregoing object is by constructing that portion
of either the oxygen passage' or the combustible
55 gas passages or both of said passages extending
provided with valves for controlling the cutting `
and heating gases discharged from the- blowpipe 45
head 4. The blowpipe is supplied with oxygen
through a hose (not shown). which is attached -
to a nipple 5. The nipple 5 is'connected to the
rear valve body 2 and the passage in the nipple
communicates with a passage 6 in .the rear valve 50
body 2. A valve ‘I in the passage 6 controls the
ilow of oxygen therein. A tube 8 connects the
passage 6 in the rear valve body 2 with an inlet
passage 9 in the forward valve body 3.
The oxygen inlet passage 9 in the forward valve 55
body 2 is divided into a cutting oxygen branch
Il. as shown in Fig. IV and a heating oxygen
branch Il, as shown in Fig. VI. The cutting
oxygen branch I8 is provided with a cutting
oxygen valve I2. which is operated by a lever I3
pivoted on a pin_ I4 on the forward valve body 3.
by a cut-oit valve 38. The combustible gas pas
sage 31 in the rear valve body 2 communicates
with a tube 38 which connects the passage 31
A projection I5 on the valve lever I3 operates
the stem I8 of the cutting valve I2 which con-v
annular combustible gas chamber 4| in the mixer
trols the flow of the >oxygen from the valve cham
10 ber inlet I 1 to the outlet I8 which is connected
to a tube I8 leading from the forward valve body
3 to a cavity 28 in the blowpipe head 4.
A nozzle 2l is connected to the blowpipe head
4 by a clamping nut 22. The nozzle 2i has a
central >cutting oxygen passage 23 therethrough
which is connected to the cavity 28 in the blow
pipe head 4.
My invention Apertains particularly to the con
duits for conducting the heating oxygen and com
20 bustible gases and the mixture of these gases to
the discharge end of _the burner nozzle 2l and how
they are constructed to prevent flashbacks. 'I'he
' construction of these passages depends upon a
number of conditions which will be hereinafter
'I'he blowpipe shown in Figs. I to
25 explained.
VII is illustrative of a medium pressure blow
- pipe.` that is, a blowpipe using up to 15 lbs. pres
of combustible gas in the
e 31 is controlled .
to a combustible gas passage 48 in the forward
valve body 3. 'I‘he latter passage 48 leads to the
- The heating oUgen is- discharged from the
forward end 32 of the mixer nozzle 33 through 10
e 42 therein. _The oxygen dis
charge from the end of the nozzle 33 mingles
with the combustible gas which flows from cham
ber 4I around the end of the mixer nozzle 33
and the two ‘gases iiow from the mixer outlet or
throat 43 to a mixing tube 44 connected at one
end to the forward valve body 3. I prefer to
make the central passage 42 in the mixer nozzle ‘
as large as _the mixer throat 43 so that in the
event of a backfire the gases in the throat can 20
pass backward into the central mixer passage 4t .
without being retarded due to a reduction in area
o! said passage as compared to the area of said
throat 43. The other end of the mixing tube 44
is connected to a‘distributing chamber 45 in the 25
blowpipe head 4. 'I'he combustible gas mixture
iiows from the distributing chamber 45 through
a plurality of combustible gas mixture passages 46
in the blowpipe nozzle 2l at the end of which thel
sure in the acetylene hose. As shown therein the
branch heating oxygen passage II‘in the forward
30 valve body 3 is provided with a heating oxygen
mixture may be ignited in the usual manner to 30
control valve 24 for controlling the iiow of the ~ produce a heating iiame.
heating oxygen from the valve inlet chamber 25
A similar type of blowpipe is shown in Figures
to the valve outlet chamber 26 which communi Y VIII to XV but the tubes are arranged in a dif
cates with a rearwardly extending conduit 2l ferent manner. 'For the purpose of rendering
35 which is connected to one end of a coiled tube 28
the blowpipe flashback resistant. the required 35
enclosed in the blowpipe handle i . ’I'he other end
of the coiled tube 28 is connected to one end of '
length of and volume in the heating oxygen con
duit between the heating oxygen control valve
-a return conduit 28 and the other end of the re
and the end of the mixer nozzle is obtained by
turn conduit 28 is connected to a passage 38 in extending the preheating oxygen conduit from
40 the forward valve body 3. The passage 38 leads -the control valve to the blowpipe head and re
to the rear portion of the gas mixer 3l. In this turning’the conduit to a mixer located a deter
case the heating oxygen control valve 24 is the mineddistance from the blowpipe head.
-iirst point nearest the mixer nozzle which oHers
In the blowpipe shown in Figs. VIII to XV the
any eiIective resistance to _the gas iiowing back
oxygen is supplied thereto through a nipple 58
ward from the discharge end 32 of the mixer, and a connecting nut 8l connected in series to a
nozzle 33 as a result of a bacmre. In such a case
valve body 52 at the -rear end oi' the blowpipe
where all other conditions which may aiIect the handle 53. A cutting oxygen valve 54 is retained
ñashback resistance have been determined ex
in a valve chamber 88 in,y the valve body 82 by
cept the length of and the volume in the passage means of the connecting/ nut Il screwed into a
50 travelled by the heating oxygen from the heat
counterbore at the outer end of the valve cham
ing oxygen valve 24- to the discharge end 32 of the ber 5S. A spring 58 is compressed between the
mixer nozzle 33, the length and volumeof this inner end of the connecting nut _8l and the outer
passage determines 'the ñashback resistance of ` ‘end of _the valve 84 and normally retains the
the blowpipe. 'I‘he coiled tube 28 is inserted in valve on its seat 51. A central bore" through
.55 the passage as a convenient means for obtaining
the connecting nut conducts oxygen from the
the desired length of and volume in the passage nipple 88 to the valve chamber II.
between the end 32 of the mixer nozzle and the
Oxygen for cutting purposes may be released
nearest point-.of- resistance to the backward iiow from the valve chamber 88 by depressing a cutting
to permit the desired recession of backflring gases oxygen valve lever 53 pivoted onV a pin 88 Ain a
60 into said passage for the prevention of ilashbacks block 8l at'thei'orward end of the handle 83.
as will be hereinafter explained.
Movement of the lever $8 is transmitted to the
The mixer 3| comprises a bore 34 formed in cutting oxygen valve 34 through a motion trans
the bottom portion of the forward valve body mitting mechanism comprising a link l2 pivoted
3. A portion of the mixer bore 34 is screw
at one end to the lever 88 and at the other end
65 threaded to receive a threaded locking ring 33a to one arm of a bell-crank lever 63 which is
which bears against the rear end of the mixer ' pivoted on a pin 33a in a block 84 in the blow
nozzle 33 which'is thereby secured in the mixer pipe handle 33. Motion is transmitted from the
bore 3'4. The end of the mixer bore 34 is closed other arm of the bell-crank lever 43 to a`-rod 4i
by a screw-threaded plug 3l.
which extends from the arm or the' bell-crank
A combustible gas such as acetylene is supplied lever to the cutting oxygen valve I4. The rod
to the gas mixer 3| through a gas hose (not 88 is slidably supported in a plug 38 which closes
shown) which maybe attached tp a nipple 38 an opening in the wall of the outlet ve 81
which ‘is attached to the rear> valve body 2. The of the valve seat I1.
passage inthe nipple 34 communicates with a
Upon depressing the cutting oxygen valve lever
76 passage 31 in the rear valve body 2. v’.I'làeillßllsl' n the cuttingoxygen valve 844s pushed am
from its seat 5I and oxygen hows from the valve
chamber 55 and the outlet passage 61 to a trans~
verse passage B8 in the valve body 52. A tube
combustible gas passage for the purpose of pre
venting flashbacks.
69, connected to the transverse passage 68, con
ducts the oxygen therefrom to the blow pipe head
10 and delivers the oxygen to a cavity ll in the
head. A Acutting nozzle 'l2 is 'secured to the blow- '
pipe head by a clamping nut 13. A central oxy
gen passage 1t is formed in the nozzle which
10 receives oxygen from the cavity 1| and delivers
it to the metal to be cut.
'The heating oxygen is conducted through a
heating oxygen passage T5 which branches off
from the main oxygen passage 58 in the cutting
valve chamber 55 as shown in Fig. XI. A valve
'it is located in the heating oxygen passage 'l5 in
the valve body 52 to control the supply of heating
nearest constriction in this passage to the mix
ing point M in the mixer. As shown, however.
striction Co, the inlet to a reservoir R0._ The
reservoir R0 is inserted in the passage D0 between
the constriction Co and the mixing point M as a_
substitute for the coiled tube 28 in Figs. I to
VII and as a> means of reducing the length of
the corresponding tube in Figs. VIII to XV. The .
volume in the passage between the heating oxy
gen control valve ‘F8 and the discharge end 'I8
of the mixer nozzle l!! to prevent flashbacks, the
oxygen is conducted Afrom the outlet passage 8U
of the control valve 'i8 to the blowpipe head 'l0
25 through a tube 8l which extends between the
outlet >passage 8G in the valve body 52 to a
transverse bore 82 in the blowpipe head. The
heating oxygen is then returned from the trans
verse bore 82 to a chamber 83 in the rear end of
30 the mixer bore 84. The oxygen is conducted be
_tween the two points through a` tube 85 which
extends between the transverse bore 82 in the
reservoir R9 is a convenient means of providing
the necessary volume in the passage D0, includ
ing the length of the reservoir R0, for a given 20
blowpipe head 18 and the valve body 52 which
is provided with a passage 85 which conducts
the oxygen from the tube 85 to the chamber 83
in the rear end 'of the mixer bore 84 closed by a
plug 81 screw threaded therein.
A combustible gas such as acetylene is supplied
to the gas mixer 'l1 through a nipple 88 which
40 is connected to a combustible gas valve casing
89 having a valve 90 therein for controlling the
ñow of gas therethrough. The outlet of the valve
casing 89 is connected to a passage 9| in the Valve
body 52 `which leads to the annular chamber 92A
45 in the gas mixer 11.
The heating oxygen discharged from the
chamber 83 in the rear end of the mixer bore 84
passes through a central bore 93 in the mixer
nozzle T9 and mixes with the combustible gas
50 which flows from the annular combustible gas
chamber 92 in the mixer 111. The oxygen mixes
with the combustible gas and forms a gas mix
ture which is conducted from _the mixer ï'l
through a tube 84 which is connected to a dis
55 tributing chamber 95 in the blowpipe head 18.
The combustible gas mixture flows from the dis
tributing chamber 95 through the combustible
gas mixture passage 96 in the blowpipe nozzle
12. The mixture may be ignited for heating pur
poses in the usual manner upon being discharged
the valve V is'placed inrear of such a con
In order to obtain the desired length and
through the hose O.> The oxygen is controlled
by the valve V. The valve V may form the
oxygen delivered to the gas mixer'l‘l. '
from the blowpipe.
As illustrated in Fig._ XVI the blowpipe is
adapted for use with both systems and for con
venience only the heating -gas passages are
shown. The oxygen is supplied to the blow-pipe
The foregoing illustrates two examples of the
application of my invention to a blowpipe _adapted
-to utilizeÍ medium pressure yacetylene with a
mixer nozzle having little or no injector `action or
in a case where the backfiring'gases are forced
backward into the heating oxygen passage for the
purpose of preventing flashbacks. The more
general application of my invention is diagram
matically illustrated in Fig. XVI. Itis here
Ashown that my invention is also applicable _to a
blowpipe utilizing low pressure acetylene or other
combustible gas with an injector mixer nozzle in
which case the backñring gases are forced up the
minimum length of DD to allow the recession >of
backñring gases thereinto and thereby prevent
flashbacks as will be hereinafter explained.
The combustible gas is supplied to the blowpipe
from a hose A through a valve V, a constriction
Ca at the inlet of a reservoir Ra in a passage De
leading to the mixing point M at the end of the
mixer nozzle. The location of the elements inl
the combustible gas passage De correspondsto .30
and may perform the same function as the cor
responding elements in the heating oxygen pas
sage Do in the event the backñring gases travel
backward into the passage De, but the length
and/or volume of the passage Da should be made 35
greater under like conditions. Upony mixing at
the mixing point M the combustible mixture of
oxygen and a combustible gas flows through the
combustible mixture passage Dm to the discharge
end of the burner nozzle N.
_ Í
l As herein used the word constriction'indica-tes
a point such as Co or" Ca nearest to the mixing
point which offers a material resistance to the
backward flow of gases and other than the re-`
sistance due to normal tube wall friction. The
passage D0 is the heating oxygen passage extend
>ing rearwardly from thedischarge end of the
mixer nozzle, that is, from the mixingvpoint to
the nearest constriction which in the usual case
is the heating oxygen valve. Da indicates a por
tion of the combustible gas passage situated in 50
a manner corresponding to D0.
Dm is the com
bustible mixture passage extending from the
mixing point to the end of the burner nozzle N.
By properly proportioning the length and vol
- ume of the passages Dm, D0 and Da in respect t0
each other for a given combustible gas consump
tion, a blowpipe having good flashback resistance
can be obtained. These proportions may be de
termined upon the following principles. A back 60
fire produces pressure in Dm and will force the
burning, burned and unburned mixture up either
the oxygen passage D0 or the combustible gas
passage Da or both of said passages'depending
uptn the pressure created thereby in the mixing 65.
tube throat. ‘and the resistance offered to the
backward ñow oi the gases in the passages De
and De. When the backfìring gases are forced
backward into either the oxygen passage Do or
the combustible mixture passage Da. the further
formation of a combustible mixture is prevented
until thebackñre gases are forced forwardly out
of each of l'he passages D@ and DB. If a suñi~
cient time elapses between the recession of the
backflring gases into the passages D0 and Da
and the return of these gases to the mixing point
to permit them to be burned out or extinguished
before the last of the backiìring gases return to
the mixing point, then there will be no ña‘shback
unless the mixing tube or particles of carbon
of ignition of the combustible mixture, although
ifl desired the return of both components of the
combustible mixture to the mixing point may be
delayed as >shown in Fig. XVI to obtain good
remaining therein are heated up to the ignition
flashback resistance.
point of the gases. The elapsed time is increased
Referring to Fig. XVI in connection with the
as the pressure in the mixer throat is increased
. and as the resistance beyond the throat is de
examples A, B, and C shown in the table below,
in the case of a blowpipe utilizing medium pres
'I'he pressure created in the mixing tube throat
may be controlled by the length and volume of
the combustible mixture passage Dm. I have
sure acetylene with a consumption up to 50 cu. it.
of acetylene per hour excellent flashback resist 10
ance was obtained.
In these examples no pro
vision was made for the backilring gases to re
found by increasing the length `oi.' this passage .ilcede into the acetylene passage. 'Therefore this
and by increasing its volume as by inserting a
chamber in this passage the pressure of the back
_ñre in the mixing tube throat has been increased
and good flashback resistance has been obtained
with reduced lengths and volumes in the gas pas
sages Do or Da.
passage was constructed as usual. In each ex- È
ample the length of Dm was 7" and its volume
was .16 cu, in.
_ '
l3. 8
33. 70
17. 6
19. 6
3. 47
7. 6
9. 6
`The resistance offered to the backward ñow of
the backñring gases in the oxygen passage and
combustible gas passage is increased by constric
tions in these passages within a minimum dis
tance back from the mixing point or the discharge
end of the mixer nozzle. The resistance to the
backward ilow of the baci-:firing gases in the pas
Ds Length in inches---_
D. Volume in cu. inches
»1° Length in inches _____ __
d, Volume in cu. inches ................... _.
. lß
. 35
. 45
In each 'of the above examples when do was
reduced in length by more than one inch, thereby
reducing D0 by the same amount, the flashback
sages Da and D. is also increased by an increase
in the normal pressure of the gases in those pas ' resistance was lowered. -I have found that the
length and volume of the passage Do and also Dn
sages and by a decrease in the volume in the pas
sages Do and/or Ds below a certain minimum for
a given length and pressure therein.
When a
backfire occurs the backñring gas will travel most ' ‘
may be increased without reducing the ñashback 30
resistance of the blowpipe.
I have also found that-when the cu. ft. of con
sumption of acetylene is increased in a blowpipe
designed to give good flashback resistance for a
From the standpoint of preventing flashbacks certain maximum consumption and a minimum 35
it isdesirable that the backñring gases travel length and volume in the passages. Da_or D; for
backwards into the oxygen passage D0 in prefer~ ' a given Dm that the length and/or volume in the
ì ence to the combustible gas' passage D. and that passages D., D» or Dm must be increased to ob
the unburned mixture be retained in the oxygen tain the same degree of ?ashback resistance.
passage D0 until it has been completely burned
While I have illustrated my invention in con 40
_and until after the combustible gas has resumed nection with a cutting blowpipe, my invention is
its forward ñow and returned> to the mixing point. equally applicable to welding blowpipes and the
invention may be applied to either the oxygen
However, blowpipes can be made flashback re
sistant by causing' the back?iring gases to travel or the combustible gas passage for preventing
backward into the combustible gas passage until - ñashbacks. Also a wide departure may be made 45
the mixture is completely burned out before re
from the examples as given herein. I therefore
,turning to the mixing point and after the return wish to limit my invention only by the scope of
l ‘L
of the'oxygen to said point. .As the combustible the claims appended hereto.
mixture burns more slowly in the combustible I I claim:
50 gas passage than itdoes in the oxygen passage,
1. A'iiashback resistant blowpipe adapted to
readily into the passage offering the least resist
it is necessary to retain the combustible mixture
in the combustible gas passage Di a. greater pe
utilize a combustion supporting gas and a com
bustible gas for producing a heating ilame, said ‘
riod of time to allow it tocompletely burn 4before .blowpipe.l comprisingv a mixer having 'a nozzle
returning to the mixing point than it is necessary and an outlet throat therein; a burner nozzle;
55 .to retain the combustible mixture in the oxygen
a conduit including said mixeì- throat i'or con 55
^ passage D0 under like conditions. Furthermore ductlngthe- combustible gas mixture to said
when the oxygen returns to the point of mixing burner nozzle; a supply conduit for conducting
vbefore the combustible gas arrives, it may sus
a combustion >supporting gas to said mixer noz
tain the combustion of any burning portions o! zle; va supply conduit for conducting a combus
carbon in that region and it may sustain the com
tible gas to said mixer; a portion oi' said supply
bustion until' the acetylene returns to that region conduit for vcombustion supporting gas connect
and be ignited in the presence of the oxygen and
thereby cause a flashback. In view of the sus
tained combustion of the carbon particles in the
65 region of the mixing point it may also beneces
sary to cause a. further delay of the return of the
ing directly with said mixer mozzle and being '
elongated and having a minimum internal cross
sectional area substantialy as large as the inter
nal area of said mixer throat; -said elongated'
portion being free from constrictions therein
and having suiilcient length and volume therein
the foregoing explanation it is necessary to delay L to> receive the unburned backñring combustible
the return to the mixing point of >only the last mixture and to retain said backiiring combustible
70 component of the combustible mixture which mixture therein until said mixture has' been com
reaches themixing point> after a backfire until pletely burned and until said combustible mix
after the flame in that component has been ex.
ture conduit and any particles remaining therein
tinguished and until after any matter -contained have been cooled below the ignition temperature o
in the mixing tube and in the vicinity of the’mix
of said combustible mixture.
ing point has been cooled below the temperature
2. A whack-resistant blowpipe adapted to
combustible gas to the mixing point. In'vlew oi.'
utilize a combustion supporting gas and a com
bustible gas for producing a heating flame, said
blowpipe- comprising a burner nozzle; a mixer;
a conduit for conducting the combustible gas
mixture to said burner nozzle; a supply conduit
fcr conducting a combustion supporting gas to
said mixer; a supply conduit for conducting a.
combustible gas to said mixer; a portion of one
of said supply conduits connecting directly with
said mixer and being elongated; said elongated
portion being free from constrictions and having
sufficient length and internal capacity to freely
receive an unburned backñring combustible mix
ture and retain the same therein until com
pletely burned, and until said combustible mix
ture conduit and any particles of carbon therein
have cooled below the ignition temperature of
said combustible mixture.
3. A ilashback-resistant blowpipe comprising a Y
burner nozzle; a gas mixer; a conduit for con
ducting a combustion-supporting gas to saidmixer; a conduit for'conducting a combustible
gas to said mixer; a conduit for’ conducting a
combustible gas mixture from said mixer to said
25 burner nozzle; a portion of one- of said ñrst two
conduits immediately in the rear of said mixer
being elongated and free from constrictions
' adapted to substantially retard the backward ñow
of gas therein and having suiiicient length and
30 internal capacity to freely receive an unburned
backñring combustible mixture and retain the
same therein until completely burned, such elon
gated portionV including a coil, and the other or
said two conduits having a part thereof sur
35 rounded by- said coil.
4.111 a flashback-resistant blowpipe, the com
bination of a blowpipe head; a burner nozzle se
cured to said head; a Valve body; a gas mixer
within said `valve body; a handle secured to said
40 valve body; means for conducting a combustible
mixture from the outlet of said' mixer to said
having sufdcient length and internal capacity to
receive an unburned backiìring combustible mix
ture and retain said backfiring combustible mix
ture therein until completely burned, and until
such combustible mixture conducting -means and 4
any particles of carbon therein have cooled below
the ignition -temperature of the combustible
5. A'ñashback-resistant blowpipe comprising a
handle; a gas mixer carried by said handle and
including a mixer nozzle; a blowpipe head se- `
cured to but spaced from said handle; a burner
nozzle connected to said head;- a conduit for con
ducting a combustible gas mixture from the out
let of said mixer to said burner nozzle; a valve
carried by said handle and controlling the sup
ply-of heating oxygen to said mixer; and a con
duit for `such heating oxygen extending from
said valve to said head and returning to the inlet
of said mixer nozzle, suchheating oxygen con- -
duit being free from constrictions and having
sufficient length and internal capacity to receive
an unburned backñring combustible mixture and
retain the same therein until completely burned.
6. In a ñashback-resistant blowpipe, the com
bination of a blowpipe'head having a bore; a>
burner nozzle secured to said head; a valve body;
a gas mixer carried by said valve body; means
for conducting a' combustiblemixture from said
mixer to said burner nozzle, such conducting 30
- means including a tube secured to said head and ~
to said valve body'; a conduit for supplying a
combustible gas to said mixer; a conduit for sup
plying a combustion-supporting gas to said
- mixer; and valves mounted on said valve body
and severally controlling the gas flow through
said conduits; one of said conduits `being elon- l
gated between its control valve and said mixer
and including two sections of tubing extending
longitudinally of the combustible mixture con 40
ducting tube and secured to said valve body and
said head in communication with said bore inV I
burner nozzle, such conducting means including to
said head, such elongated conduit being free
a tube secured to said head and to said valve >from constrictions and having suilicient length.,
body; a conduit -for supplying a combustible gas
and internal capacity to receive an unburnedsf45
backñring combustible mixture and to retain
bustion-supporting gas to said mixer; and valves ~said backñring combustible mixture therein un
mounted on said valve body and severally con
til completely burned and until such combus
trolling the -flow of gas through said conduits, tible mixture conducting means and any particles Y '
one of said conduits being elongated between its of carbon therein have cooled below the ignitioncontrol valve and said mixer and including a coil
within _said handle, such elongated conduit being temperature of the combustible mixture.
free from constrictions adapted substantially to'
, to said mixer; a conduit for supplying a-com
retard the backward now of gas therein and
Без категории
Размер файла
1 049 Кб
Пожаловаться на содержимое документа