Improvements in the Distribution and Mixing of the In- flammable Gases or Vapours and Air Utilized in Gas or Blow-pipe Welding or Heating, and in Apparatus connected therewith.
Year: 1889

page_text: Date of Application, 28th Nov., 1889
Complete Specification Left, 26th Aug., 1890-Accepted, 11th Oct., 1890
PKUYIDIONAL DI MULTIUATIOA
Improvements in the Distribution and Mixing of the In-
flammable Gases or Vapours and Air Utilized in Gas or
Blow-pipe Welding or Heating, and in Apparatus connected
therewith.
We, GEORGE HERBERT LLOYD of Maney House, Sutton Coldfield, SAMPSON
SAMUEL LLOYD the younger of Nile Street, Birmingham Manufacturers, and
WILLIAM SEDDON SUTHERLAND of Sandon Road, Edgbaston Engineer, all in the
County of Warwick do hereby declare the nature of this invention to be
follows:-
as
In existing systems of blow pipe or gas welding, the mixture of inflammable gas
and air is conducted to the various blow pipe and gas furnace appliances by means of
pipes and occasionally it accidently fires back, and the explosion so caused is liable to
damage portions of the apparatus.
The object of our invention is to avoid danger of this kind by providing arrange-
ments which allow the gas and air to be mixed at or near the furnace or blow pipe to
or furnace, the system of
be supplied so that except at or near each blow pipe
distributing pipes carried throughout the works contains no gaseous fluid or mixture
capable of exploding.
In carrying one mode of our invention into effect we compress the coal or other
inflammable gas, by means of a compressing pump of any well known construction
and conduct it under pressure, through suitable pipes to the various points where the
blow pipes or gas furnaces are set up. At or near the blow pipes or furnaces we
arrange injectors so constructed that the issuing jet of gas under pressure induces an air
current to enter the apparatus from the atmosphere, and this entering air mixes with
the gas to form a combustible or explosive mixture in the proportion required to
produce the desired temperature. The pressure to which the gas is compressed and
the proportions of the injector jets and openings are so arranged that the mixture
formed at the injector is delivered into the passage, chamber or pipe leading to or
forming a part of the gas furnace with a sufficient velocity to accomplish the work
required of it and the pressure of the gas and proportions of the injector may be
varied considerably in a manner well understood to produce various ratio of flow
volumes and pressure of gaseous mixture.
Instead of compressing inflammable gas and distributing it through pipes to the
injectors, there to mix with air we may compress the whole or a greater or less
portion of the air supply required for combustion and distribute the compressed air
through pipes to the injectors. We then cause the air jet issuing in the injector
under pressure to induce a current of gas and mixing with it pass on to the furnace or
blow pipe.
When the whole of the air supply is compressed and distributed the injector is so
constructed that it draws a supply of inflammable gas only from the gas pipes carrying
the gas under the ordinary slight pressures but when only a portion of the air supply
is compressed the injector is constructed to draw a further supply of air from the
In this case
atmosphere as well as the combustible gas from the ordinary gas pipes.
the air requires to be compressed to a higher pressure, than when the whole air
supply is compressed and distributed so that the energy of flow from the injector jet
may be sufficient to induce a further supply of air delivered to the blow pipe or
furnace at the required pressure to accomplish its work.
In some cases a mixture of gas and air may be made at the compressing pump in
such proportions that it cannot be exploded and this mixture may be delivered through

page_text: the distributing pipes under pressure to the injectors where it may be mixed with a
further supply of air and gas, or gas only or air only, in the proper and well known
proportions and the mixture so formed may be passed on to the blow-pipe or furnace
and utilized in the usual manner; but we prefer to fill the distributing pipes and
system either with inflammable gas only or air only a
as we thereby secure complete
safety from explosion in the distributing pipes or system without any delicacy of
adjustment.
Öne essential feature of our system however lies in the distribution of a gaseous fluid
through the distributing pipes, which fluid is of such nature or composition that it is
non-explosive and only becomes so after passing the injector and mixing with the
additional gaseous fluid then admitted so that mixtures of gas and air also may be
distributed to the injectors without departing from the essentials of our invention
provided they are of such proportion or composition as to be non-explosivé.
Instead of using permanent inflammable gas, such as coal or water gas, we may
cause the compressed air jet at the injector to take in a supply of inflammable vapour
such as hydro-carbon vapour, and mix with it to form the required combustible
mixture. When heavy oils or hydro-carbons are used we heat the air supply and
keep the mixture hot after passing the injector so that the vapour may not
condense.
The injector used maybe of any ordinary construction as at present in use forblowing
furnaces or supplying air under pressure, we vary the construction to suit the con-
ditions, namely to suit gas only in the distributing pressure pipes, or air only or a
mixture of gas and air. When gas only is used under pressure the jet area is mado
adjustable and the inlet air area is also made adjustable. When air under pressure is
used we allow the induced flow of gas to take place through a number of holes
controlled by a sliding or rotating piece or ring and when air also is required we
apply similar adjustment.
The furnace or blow pipe may be of any ordinary construction but in some cases
where we wish to distribute the temperature uniformly over a considerable surface or
reduce the velocity of flame flow we pass the mixture through a series of small holes
in a plate or plates which may be cooled by water circulation to prevent back ignition
into the short pipe passage or chamber communicating with or forming part of the
furnace.
It is important that the gas or air inducing the current in the injector should work
under as even a pressure as possible and free from vibration.
We in some cases secure this steadiness by employing a governor which may consist
of an arrangement of weighted regulating bellows or of an apparatus acting on the
principal of an ordinary gas governor. By this method of working we are enabled to
use the mixed gas and air at a velocity more nearly corresponding to the velocity
of explosion backwards; than in any other system thereby preventing oscillation in
the flame and consequent loss of heat and temperature.
With a view to avoiding explosion running backwards to the injector when ceasing
working in some cases we so arrange the adjustments controlling the flow of gas or
air from the pipes under pressure that the mixture changes its nature and becomes
more or less dilute and non explosive as fast as the supply is cut off so that all
chance of even a slight explosion into the chamber passage or pipes backward is
avoided.

page_text: COMPLETE SPECIFICATION.
Improvements in the Distribution and Mixing of the In-
flammable Gases or Vapours and Air Utilized in Gas or
Blow-pipe Welding or Heating, and in Apparatus therewith.
We, GEORGE HERBERT LLOYD of Maney House, Sutton Coldfield, SAMPSON
SAMUEL LLOYD the younger of Nile Street, Birmingham Manufacturers, and
WILLIAM SEDDON SUTHERLAND of Sandon Road Edgbaston Birmingham, Engineer,
all in the County of Warwick, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
In existing systems of blow pipe or gas welding, the mixture of inflammable gas
and air is conducted to the various blow pipe and gas furnace appliances by means of
pipes and occasionally it accidentally fires back, and the explosion so caused is liable
to damage portions of the apparatus.
The object of our invention is to avoid danger of this kind by providing arrange-
ments which allow the gas and air to be mixed at or near the furnace or blow pipe to
he supplied so that except at or near each blow pipe or furnace, the system of
distributing pipes carried throughout the works contains no gaseous fluid or mixture
capable of exploding.
In carrying one mode of our invention into effect we compress the coal or other
inflammable gas, by means of a compressing pump of any well known construction
and conduct it under pressure, through suitable pipes to the various points where the
blow pipes or gas furnaces are set up. At or near the blow pipes or furnaces we
arrange injectors so constructed that the issuing jet of gas under pressure induces an
air current to enter the apparatus from the atmosphere, and this entering air mixes
with the gas to form a combustible or explosive mixture in the proportion required
to produce the desired temperature. The pressure to which the gas is compressed and
the proportions of the injector jets and openings are so arranged that the mixture
formed at the injector is delivered into the passage, chamber or pipe leading to or
forming a part of the gas furnace with a sufficient velocity to accomplish the work
required of it and the pressure of the gas and proportions of the injector may be
varied considerably in a manner well understood to produce various ratio of flow
volumes and pressure of gaseous mixture.
Instead of compressing inflammable gas and distributing it through pipes to the
injectors, there to mix with air we may compress the whole or a greater or less
portion of the air supply required for combustion and distribute the compressed air
through pipes to the injectors. We then cause the air jet issuing in the injector
under pressure to induce a current of gas and mixing with it pass on to the furnace
or blow pipe.
When the whole of the air supply is compressed and distributed the injector is so
constructed that it draws a supply of inflammable gas only from the gas pipes
carrying the gas under the ordinary slight pressures but when only a portion of the
air supply is compressed the injector is constructed to draw a further supply of air
from the atmosphere as well as the combustible gas from the ordinary gas pipes. In
this case the air requires to be compressed to a higher pressure, than when the whole
air supply is compressed and distributed so that the energy of flow from the injector
jet may be sufficient to induce a further supply of air delivered to the blow pipe or
furnace at the required pressure to accomplish its work.
In some cases a mixture of gas and air may be made at the compressing pump in
such proportions that it cannot be exploded and this mixture may be delivered through
the distributing pipes under pressure to the injectors where it may be mixed with a
further supply of air and gas, or gas only or air only, in the proper and well known
proportions and the mixture so formed may be passed on to the blow pipe or furnace
and utilized in the usual manner; but we prefer to fill the distributing pipes and
system either with inflammable gas only or air only as we thereby secure complete

page_text: safety from explosion in the distributing pipes or system without any delicacy of
adjustment.
One essential feature of our system however lies in the distribution of a gaseous
fluid through the distributing pipes, which fluid is of such nature or composition that
it is non-explosive and only becomes so after passing the injector and mixing with
the additional gaseous fluid there admitted so that mixture of gas and air also may be
distributed to the injectors without departing from the essentials of our invention
provided they are of such proportion or composition as to be non-explosive. Instead
of using permanent inflammable gas, such as coal or water gas, we may cause the
compressed air jet at the injector to take in a supply of inflammable vapour such as
hydro-carbon vapour, and mix with it to form the required combustible mixture.
When heavy oils or hydro-carbons are used we heat the air supply and keep the
mixture hot after passing the injector so that the vapour may not condense.
The injector used may be of any ordinary construction as at present in use for
blowing furnaces or for supplying air under pressure. We vary the construction to
suit the conditions, namely to suit gas only in the distributing pressure pipes, or air
only, or a mixture of gas and air. When gas only is used under pressure the jet area
is made adjustable and the inlet air area is also made adjustable. When air under
pressure is used we allow the induced flow of gas to take place through a hole or a
number of holes controlled by a sliding or rotating piece or ring and when air also is
required we apply similar adjustment.
The furnace or blow pipe may be of any ordinary construction but in some cases
where we wish to distribute the temperature uniformly over a considerable surface or
reduce the velocity of flame flow we pass the mixture through a series of small holes
in a plate or plates which may be cooled by water circulation to prevent back ignition
into the short pipe passage or chamber communicating with or forming part of the
furnace.
It is important that the gas or air inducing the current in the injector should work
under as even a pressure as possible and free from vibration. We in some cases secure
this steadiness by employing a governor which may consist of an arrangement of
weighted regulating bellows or of an apparatus acting on the principle of an ordinary
gas governor. By this method of working we are enabled to use the mixed gas
and air at a velocity more nearly corresponding to the velocity of explosion
backwards, than in any other system, thereby preventing oscillation in the flame and
consequent loss of heat and temperature.
With a view to avoiding explosion running backwards to the injector when ceasing
working; in some cases we so arrange the adjustments controlling the flow of gas or air
from the pipes under pressure, that the mixture changes its nature, and becomes more
or less dilute and non-explosive as fast as the supply is cut off, so that all chance of
even a slight explosion into the chamber passage or pipes backward is avoided.
In the accompanying drawings
Fig. 1 is a section of the injector we adopt when we compress the inflammable gas
alone in the distributing main.
Fig. 2 is a section of an injector suitable for utilizing compressed air or a mixture
of gas and air compressed in the mains, while
Figs. 3 and 4 are transverse and longitudinal sections of an injector so arranged
that no mixing of inflammable but non-explosive gas or mixture occurs until the
mixture arrives at or very near the point of combustion in the welding furnace.
Fig. 5 is a diagrammatic elevation showing the mode of arranging our system as
applied to a number of furnaces.
Referring to Fig. 1, the gas supply is compressed by any convenient known form
of compressing pump into the gas main pipe or pipes which communicate with the
injector A by means of the branch pipe B; from the pipe B the gas passes to the
injector jet or nozzle C and so a current of air is induced to enter the second jet or
nozzle D as shown by the arrows. Thence the mixture of gas and air so formed
passes by the passage E and a suitable connecting pipe to the gas furnace which may
be of any known construction as at present used. The injector is arranged to be as

page_text: close to the furnace as possible in order to avoid the presence of a considerable volume
of explosive mixture between the furnace and the injector as we have hereinbefore
explained. The second nozzle D is constructed so as to be capable of adjustment and
this is conveniently effected in one way by the hand wheel F and pinion G which
when rotated cause it to slide.
When it is desired to increase the proportion of inflammable gas present in the
mixture of gases discharged from the injecter the second nozzle D is caused to slide
towards the injector jet or nozzle C and so diminish the area of the annular passage
through which air is admitted. The air supply is thus reduced and the mixture
becomes richer in gas.
When more air is required D is moved away from C and so the air inlet area is
increased and the mixture takes a larger proportion of air.
When the welding or other furnace operation is completed and the blast is to be
stopped, the second nozzle D is moved down till it comes in contact with the nozzle C
and so the air supply is stopped. The pipe leading from the injector to the furnace
becomes filled with gas alone and when the gas is shut off behind the injector the
flame from the furnace cannot fire back and explode the mixture in the pipe as would
be the case if explosive mixture existed there.
Referring to Fig. 2 which shows an injector suitable for the case where the whole
air supply is compressed into the main pipes or where a non-explosive mixture of gas
and air is supplied to the main; the injector H has an injector jet I which is supplied
with compressed air from the main and a closed chamber K into which there is a gas
inlet passage L; the movable second jet or nozzle M is controlled as in Fig. 1 by a
similar wheel N and pinion O and the explosive mixture passes by the passage P to a
pipe leading to the furnace. The air jet passing from I to M causes a partial vacuum
in the chamber K and so gas flows by the gas inlet passage L and mixes with the air
of the jet. The proportion of gas to air may be varied by moving the second jet or
nozzle by the hand wheel N and pinion 0. When the main is supplied with a
compressed non-inflammable mixture of gas and air the construction of injector
remains as in Fig. 2 but the adjustment of the second jet or nozzle M is altered so as
to take in less additional gas by the gas inlet passage L.
When the gas main is supplied with a mixture rendered non-explosive by containing
an excess of gas, air is admitted by the passage L or two passages such as L may
open the closed chamber K and both air and gas may be admitted to it, so as to utilize
a small portion of gaseous fluid in a highly compressed state in the supply main to
propel and formby means of an injector any requiredvolume ofmixture of an explosive
character. Figs. 3 and 4 are transverse and longitudinal sections of a special type of
injector intended to form explosive mixture in the immediate vicinity of the furnace
where it is to be used. By this arrangement the explosive mixture is only formed at
the exact position where it is wanted and so no pipes or passages are filled with such
mixture. A flat shaped vessel such as A' Figs. 3 and 4 is supplied with inflammable gas
under pressure by a passage Q and a number of small holes R, R1, R2, R³, R*, R³, Řº,
etc. are drilled in its lower part; opposite these holes in another casting S (made
hollow so as to contain cooling water) are drilled a corresponding number of
holes U, U1, U2, U3, etc. of larger diameter and preferably made conical, the greater
diameter being next the holes R, R1, R2,etc. The vessel A¹ is so mounted that the
distance between the jets R R R2, etc. from the lower holes U U¹² U³ U etc. may be
varied. The gas under pressure passes in jets from the holes R, R1, R2, R3, R+, etc.
and by induction, air mixes with it as shown by the arrows Fig. 3, and the mixture
proceeds through the lower holes U, U¹, U², U³, U, Us, etc., the proportions of gas
and air being adjusted by the distances of the two sets of holes, the greater the
distance the more the air, the smaller the distance the less the air. The holes R R¹ etc.
together with the holes U, U1, U2, etc. form a simple injector acting as hereinbefore
described. Instead of a row of holes in the nozzle vessel we sometimes make use of
slot shaped holes, or a long slot induces the air current as already described.
In this case the aperture or apertures in the bottom plate S is or are made to
correspond. The plate T and the fire bricks V form the surface, and the flame

page_text: produced plays upon the metal to be welded W as seen in Fig. 3. By this simple
arrangement we provide an injector furnace in which we can heat up considerable
lengths of metal to the welding point. The lengths of the castings A¹ and S are made
in accordance with the length of the metal piece or tube to be operated on. The
casting S is preferably made hollow as shown so that a water jacket may be applied to
keep down the temperature, but in some cases we may dispense with the water jacket
and form the casting S in the configuration of a simple plate with the holes U U U
ctc. At Fig. 5 we show a diagrammatic elevation of the application of our system to
a set of gas furnaces. The gas pump a driven in any ordinary way takes in a supply
of inflammable gas and forces it into the main pipe b, whence it is distributed by the
branches c, d, e, to the injectors f, g, h, which supply the furnaces indicated at k, l, m.
The distributing systems remains the same whatever inflammable fluid we adopt,
whether gas or air and gas, or whether air alone is pumped into the main pipe and the
gas added by the inductive action of the jets at the injectors.
In all cases, however, the characteristic feature of our system is maintained, namely
the use of non-explosive gaseous fluid in the distributing main pipes and the reduc-
tion of the explosive volume which exists in the system at any moment to the minimum
quantity.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
(1) In gas or blowpipe welding or heating plant, the use of a system of distribution
of the inflammable fluid in which the main distributing pipes are filled with com-
pressed non-explosive gaseous fluid and the explosive gaseous mixture is formed by
injectors which feed the furnaces, so that no explosive mixture exists in the system
except between the injectors and the furnaces, substantially as and for the purposes
herein before described and illustrated in the drawings.
(2) In an injector blowpipe welding and heating furnace, the method of mixing
the gases at the point of combustion without the aid of intermediate pipes between the
injector and furnace.
(3) In gas welding or heating plant the use of an injector furnace in which a non-
explosive gaseous fluid is discharged through a number of small holes slits or slit in a
vessel, through air or inflammable gas, into a corresponding number of opposing
holes or slits from which the explosive mixture so formed burns in a furnace, substan-
tially as hereinbefore described and illustrated, with reference to Figs. 3 and 4 of the
accompanying drawings.
(4) In gas or blowpipe welding or heating plant the use of an adjusting piece
to change the composition of the mixture formed by an injector for the purposes
hereinbefore described..
(5) In injector blowpipe welding or heating plant the method of stopping the
apparatus without back explosion by means of cutting of all, or a portion of the
induced current.
(6) The system of injector blowpipe welding and heating by which gaseous fluid
under pressure whether gas or air or a mixture of both induces a corresponding
current of the necessary gaseous fluid to. form a perfectly combustible mixture, so
mixed as to burn close to the point of ignition substantially as described.
Dated this 25th day of August 1890.
MARKS & CL1 RK,
13, Temple Street, Birmingham, Agents for Applicants.
MARKS & CLI RK,
13, Temple Street, Birmingham, Agents for Applicants.