Certain Improvements in Atmospheric Gas Burners.
Year: 1894

page_text: Date of Application, 9th July, 1894
Complete Specification Left. 6th May, 1895-Accepted, 8th June, 1895
PROVISIONAL SPECIFICATION.
Certain Improvements in Atmospheric Gas Burners.
1, GEORGE ERNEST WRIGHT, of Essex Works, Thimble Mill Lane,
Birmingham, Warwickshire, Managing Director of John Wright and Company,
Limited, do hereby declare the nature of this invention to be as follows:-
:-
This invention consists of the hereindescribed improvements in atmospheric gas
burners for gas fires and for other purposes my improvements being directed to
prevent what is known as "lighting back at the gas inlet nozzle when the gas is.
being burnt at a low pressure or when there is a back draught on the burner.
Iu carrying out my invention I make that part of the mixing pipe or chamber
through which the mixed gas and air first pass after entering the mixing pipe or
chamber of smaller area than that part of the mixing pipe or chamber through
which the mixed gas and air pass immediately before being burnt; this part of
diminished area extending for some short distance in front of the gas inlet nozzle
or nozzles. This can be accomplished in various ways such as by making the pipe
or chamber which surrounds the gas iulet nozzle and in which is the air inlet
orifice or orifices in the form of a short pipe of small area opening out into a pipe
of larger area leading to the part where the air gas mixture is burnt; or the
mixing pipe or chamber may gradually diminish in area to or towards the gas
inlet nozzle or nozzles.
Surrounding the pipe or chamber in which is the air inlet orifice or orifices as
stated above, I provide a larger outer pipe or casing open at the end farther from
the gas inlet nozzle or nozzles so that the air before entering the inlet orifice or
orifices has to travel backwards along the space between this outer pipe or casing
and the inner pipe and then turn sharp round through the inlet orifice or orifices
by the gas inlet nozzle or nozzles and travel aloug mixed with the gas in the
opposite direction to that in which the air entered the open end of the outer pipe
er casing.
As the gas aud air mixture flows through the first part of the mixing pipe or
chamber which is of diminished area more quickly than through the said part of
enlarged area nearer to the outlet, it follows that if the gas and air should be
burning at such a low pressure as to burn back down the enlarged part of the
nixing pipe or chamber any further burning back down the part of diminished
area is wholly or partly prevented by the increased speed at which the mixed gas
and air are issuing through this part so that instead of burning back to the nozzle
the flame will, as long as the low pressure continues, alternately burn down to the
part of diminished area and then rise up again and burn at the outlet. By
providing the outer pipe or casing arranged as aforesaid the air space within this
casing round the air inlet orifice or orifices forms an air buffer which in the event
of a back draught checks this back draught so far as to prevent the gas lighting at
the gas inlet nozzle or nozzles.
Dated this 7th day of Inle 1804
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.

page_text: Certain Improvements in Atmospheric Gas Burners.
I, GEORGE ERNEST WRIGHT, of Essex Works, Thimble. Mill Lane,
Birmingham, Warwickshire, Managing Director of John Wright, and Company
Limited, 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:-
"
This invention consists of the hereindescribed improvements in atmospheric gas
burners for gas fires and for other purposes my improvements being directed to
minimise the risk of what is known as "lighting back at the gas inlet nozzle
when the gas is being burnt at a low pressure or when there is a draught acting on
the burner.
24
Surrounding the inlet end of the mixing chamber I provide according to this
invention a larger outer casing or larger outer casings so arranged that the air before
entering the inlet orifice or inlet orifices has to travel backwards along the space
between this outer casing and the inner pipe and then turn sharp round through
the inlet orifice or orifices so that the air space within this casing round the air
inlet orifice or orifices. will form an air buffer or air baffle which in the event of
the flame flashing back offers a resistance to the back pressure thereby created and
as hereinafter described so far checks the backward travel of the flame as to
prevent the gas lighting at the gas inlet nozzle or nozzles.
In order that my said invention may be well understood and carried into practice
I have, on the accompanying drawing, to which I will now refer, illustrated my
said invention as applied to two gas burners for a gas fire, the said gas burners
being shewn in part sectional plan by Fig. 1 and in part sectional elevation by
Fig. 2. As these two gas burners are both of the same construction (except that
one of them is right hand and the other left hand) the description of the left hand
burner which is shewn partly in section will be sufficient.
A is the gas pipe conveying gas to both burners as is usual and b' is the gas
inlet nozzle. Cis the mixing pipe or chamber having an inlet orifice at one end c
or the gas and air and outlets d''d d³ d' at the other end where the mixed
air are burnt.
gas and
The said outer casing, which according to this invention I provide round the
inlet end e¹ of the inner pipe or chamber C, consists of two parts (or as hereinafter
described the said casing may be made in one part or in more than two parts)
marked respectively DD' of which the part D is like a bell rather larger than
the inlet end c¹ of the pipe or chamber C and encloses and extends some little
aistance along the same, and the outer part D2 is like a larger bell enclosing the
part D so that the air, before entering the inlet orifice c¹, has to pass along the
spaces in the outer casing D' D in the direction shewn by the arrows so that in
the event of the flame flashing back through the mixing chamber the flash or
explosion in the mixing chamber will force the mixed air and gas back towards the
outer casing Di D' where the various turns shewn by the arrows will so baffle the
mixed air and gas as to form an air buffer the elasticity of which will force
the flame forward again and thus prevent the gas lighting at the gas, inlet
nozzle b.
+
-151
For convenience of manufacture the part D' of the outer casing is made separate
from the pipe C and outer portion D² and secured to the latter by screws ec
Fig. 2. but it will be evident that without departing from the nature of my invention
these parts may be all cast, together.
I find the construction and arrangement of the outer casing D₁ D' as above
described and illustrated on my drawing to answer well in practice but it will be
evident that without departing from the nature of my invention the outer casing

page_text: may be constructed so as to make the air inlet passage more tortuous than shewn
by the arrows on my drawing but the effect would still he the same namely to
baffle the mixed air and gas and form an air buffer when from any cause there is a
flash back, the elasticity of this buffer forcing the flame forward again and
preventing the gas lighting at the gas inlet nozzle b as stated above.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The bereindescribed improvements in atmospheric gas burners to prevent the
gas lighting at the gas inlet nozzle, consisting of the combination, with the gas and
air mixing pipe or chamber as set forth, of the outer casing surrounding the air
inlet orifice or orifices and so arrauged with tortuous air inlet passages as described
that when there is a flash back in the mixing pipe or chamber the air in the outer
casing will be baffled and form an air buffer and by its elasticity will force the
flame forward again and prevent the gas lighting at the gas inlet nozzle as set
forth.
2. In combination with the gas and air mixing pipe or chamber of an atmospheric
gas burner, the employment of the outer casing Di D' constructed and applied in
the manner substantially as described and shewn so as to form an air buffer for the
purpose set forth.
Dated this 4th day of May 1895.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.