Improvements in Gas Fires.
Year: 1897

page_text: Date of Application, 17th Nov., 1897
Complete Specification Left, 17th Aug., 1898-Accepted, 1st Oct., 1898
Improvements in Gas Fires.
I, JOHN JAMESON, of Akenside Hill, in the City and County of Newcastle-
upon-Tyne, Consulting Engineer, do hereby declare the nature of this invention
to be as follows:-
My invention of improvements in gas fires consists in improvements in the use
of very fine filaments of highly resistant material to absorb and radiate the heat
contained in the mixture of air and gas which produces what is called a Bunsen
flame. In gas fires of the description which the aim of my invention is to
improve it is usual to employ filaments of asbestos suspended in the flame either
loose or contained in a light iron or other case, so as that the flame can impinge
upon them. Such fires are also made with spiral iron or other wire, or ravellings
of iron or other wire which, although it becomes oxidiséd and often coated with
a film of more or less combined carbon, yet retains for a long time its shape
and remains efficient.
The object attained by introducing any material substance into the Bunsen
flame is the absorption of a portion of the heat upon a radiant surface; and the
greater the degree of heat so produced upon the surface the more efficient is the
radiation.
Now I by my invention construct the material of a gas fire in the first place
to allow as little as possible of the heat to escape by conduction or otherwise in a
backward or undesired direction and next to have filaments so thin as to attain at once
the highest possible degree of heat. I construct the back or bottom of the fire
of efficient non-conducting material and over it I place a layer of non-conducting
material capable of enduring a very high degree of heat and over that I place
again the material of what are known as incandescent gas mantles arranged so
as to bring it, in a finely divided state, into the Bunsen Hame.
For this purpose I employ not the mantle itself which is usually employed
for lighting purposes, but the material as prepared for such mantles, and I attach
it by any convenient means to the non-conducting material behind or below it.
The mantle material may be arranged in any convenient way in simple filaments
or in ribbons or bands of knitted or woven material, and it may be combined
in such attachment with fine asbestos thread if desired so as to give increased
tenacity; and it may or may not be protected by a sheet or sheets of mica, glass,
or other protecting transparency.

page_text: and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
My invention of improvements in gas fires consists in improvements in the use
of very fine filaments of highly resistant material to absorb & radiate the heat
contained in the mixture of air & gas which produces what is called a Bunsen
flame. In gas fires of the description which the aim of my invention is to
improve it is usual to employ filaments of asbestos suspended in the flame either
loose or contained in a light iron or other case so as that the flame can impinge
upon them. Such fires are also made with spiral iron or other wire, or ravellings
of iron or other wire which, although it becomes oxidised and often coated with
a film of more or less combined carbon, yet retains for a long time its shape and
remains efficient.
The object attained by introducing any material substance into the Bunsen
flame is the absorption of a portion of the heat upon a radiant surface, and the
greater the degree of heat so produced upon the surface the more efficient is the
radiation.
Now I by my invention construct the material of a gas fire in the first place
to allow as little as possible of the heat to escape by conduction or otherwise in a
backward or undesired direction and next to have filaments so thin as to attain at
once the highest possible degree of heat. I construct the back or bottom of the fire
of efficient non-conducting material and over it I place a layer of non-conducting
material capable of enduring a very high degree of heat and over that place
again the material of what are known as incandescent gas mantles arranged so
as to bring it, in a finely divided state, into the Bunsen Hame.
For this purpose I. employ not the mantle itself which is usually employed
for lighting purposes but the material as prepared for such mantles, and I attach
it by any convenient means to the non-conducting material behind or below it.
The mantle material may be arranged in any convenient way in simple filaments
or in ribbons or bands of knitted or woven material, and it may be combined
in such attachment with fine asbestos thread if desired so as to give increased
tenacity and it may or may not be protected by a sheet or sheets of mica, glass
or other protecting transparency.
In order to avoid confusion of ideas I may first define the meaning I attach
to the words " a Bunsen flame." I would have it to be understood that it is not
only the flame which is produced by the use of the apparatus known as a Bunsen
burner, although that is a very convenient form of apparatus for the purpose.
But it is that description of flame in which by an adequate supply of air both
the hydrogen and the carbon of ordinary coal gas are consumed so perfectly
as that no deposit of soot is produced on any article which may be held in the
flame and in which comparatively little light is produced by what I believe to
be the incandescence of the contained carbon in such part of the flame as is
without sufficient supply of air for perfect combustion. What I consider to be
the most perfect Bunsen flame is one in which the exact equivalent of oxygen
required for the complete combustion of the hydrogen and the carbon is present,
and so mixed with the gas or so mixing with the gas as it burns as to give
perfect combustion and the highest degree of heat. A diminished supply of air
does not adequately consume the carbon and an increased supply of air dilutes
the intensity of heat produced, in both conditions however a Bunsen flame may
be used. And if an ordinary gas jet be turned down so low as only to produce
a small tip of blue flame and free access of air be allowed to it that may be also
called a Bunsen flame although is is produced on a common gas jet.
In my improved gas fire I use a Bunsen flame as thus defined, and one, so far
as practicable and convenient, arranged to give the greatest intensity of heat.
For simplicity I will describe a form of gas fire according to my invention
premising however that I do not confine myself to any special form or arrange-
ment seeing that such form or arrangement may be varied within wide limits.

page_text: Fig. 1 is a plan and end view of an ordinary gas fire burner, part of which is
shewn in section. Fig. 2 is an end view of a slight modification of it which
I prefer to use, the difference being that the burners are turned horizontally out-
wards so that when the gas is turned off the slight explosion which is produced is
not directed against the tender filaments afterwards described but in another
direction. I use a back for my fire made of fireclay perforated with numerous
small holes symetrically arranged, on which I place and secure a piece or several
pieces of asbestos cardboard with corresponding holes. The flame of the fire
passes upwards over this asbestos cardboard. I then take a supply of prepared
cotton such as is used in the Welsbach or Sunlight or other incandescent mantles
used as illuminating appliances, and I form it into tufts or small brushes secured
within twisted wires as shewn in Fig. 3; or in any other convenient manner
secured, and I place a tuft or small brush with its securing wire in each of the
holes in the back of the fire.
The tufts or small brushes may be of plain thread or not, or strips of tarlatan
or muslin or a crocheted or knitted structure and I may use various chemicals
in the preparation of these tufts or small brushes so as to give variety of colour
when ignited.
When a tuft or small brush is injured I take it and the wire which carried it
out of the back of the fire and replace it by a new tuft or small brush.
Fig. 4 is a section on a much reduced scale of the whole gas fire as arranged
complete. A. A being the perforated fire brick with a front and backing of
asbestos cardboard. B is the gas mixing apparatus shewn in Figs. 1 & 2.
The
space C is filled with asbestos fibre. D is the chimney. EE are the tufts or
small brushes of incandescent material.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
The use of such chemically prepared material as is used for incandescent gas
lighting, for the production of radiant heat in gas fires substantially as described.
Dated this Sixteenth day of August 1898.