IMPROVEMENTS IN STEAM-BOILER AND OTHER FURNACES FOR BURNING GAS
Year: 1881

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills, of the Firm of Harris
and Mills, of 23, Southampton Buildings, in the County of Middlesex, Patent
Agent, for an Invention of "IMPROVEMENTS IN STEAM-BOILER AND OTHER
FURNACES FOR BURNING GAS." A communication from abroad by Alexander
Lyman Holley, of Brooklyn, in the County of Kings and State of New York,
United States of America, Consulting Engineer.
"
PROVISIONAL SPECIFICATION left by the said Benjamin Joseph Barnard
Mills at the Office of the Commissioners of Patents on the 3rd February
1881.
BENJAMIN JOSEPH BARNARD MILLS, of the Firm of Harris and Mills, of
23, Southampton Buildings, in the County of Middlesex, Patent Agent.
IMPROVEMENTS IN STEAM BOILER AND OTHER FURNACES FOR BURNING GAS."
A communication from abroad by Alexander Lyman Holley, of Brooklyn, in the
County of Kings and State of New York, United States of America, Consulting
Engineer.
The use of gaseous fuel for steam boilers has, among others, the following
advantages:-The boiler is not injured by the influx of cold air due to firing solid
fuel in the ordinary manner; complete combustion may be maintained, and fires in
improved gas producers as compared with those in ordinary boiler furnaces may be
cleaned with less labour and less waste of fuel.
A serious objection to the use of gas fuel for boilers has been the incompleto
combustion of the gas, due to its being cooled before combustion, by the com-
paratively cold surfaces of the boiler, and also due to the imperfect mixture of air
and gas.
The present Invention relates to means for the admission of gas and air, and to
the construction of a furnace which provides the conditions of complete combustion,
and which is also cheap and durable. The conditions of combustion are a complete
mechanical mixture of air and gas, room for combustion, and a temperature of the
combustion chamber which will ignite the combustible mixture.
In this Invention the above conditions are provided for by a combination
apparatus, consisting of alternate gas and air ports, and an arch or diaphragm so
placed over them as to throw together the jets issuing from the said ports, and
form a hot chamber in which the gases are mixed, ignited, and burned in contact
with hot walls, before reaching the comparatively cool boiler surfaces.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Benjamin Joseph Barnard Mills in the Great Seal Patent Office
on the 3rd August 1881.
"
BENJAMIN JOSEPH BARNARD MILLS, of the Firm of Harris and Mills, of
23, Southampton Buildings, in the County of Middlesex, Patent Agent.
IMPROVEMENTS IN STEAM BOILER AND OTHER FURNACES FOR BURNING GAS."
A communication from abroad by Alexander Lyman Holley, of Brooklyn, in the
County of Kings and State of New York, United States of America, Consulting
Engineer.
The use of gaseous fuel for steam boilers has among others the following
advantages: :-
Complete and regular combustion may be maintained, and injury to the boiler by
the influx of cold air which occurs in firing solid fuel is avoided, as well as the loss
of fuel and labour involved in drawing the fire and cleaning the furnaces.
A serious objection to the use of gas fuel for boilers has been the incomplete
combustion of the gas, due to its being cooled before combustion by contact with
the comparatively cold surfaces of the boiler, and also due to the imperfect mixture
of air and gas.
The present Invention relates to means for the admission of gas and air, and to
the construction of a furnace which provides the conditions of complete combustion,
and which is also cheap and durable. The conditions of combustion are a complete
mechanical mixture of air and gas, room for combustion, and a temperature of the
combustion chamber which will completely ignite the combustible mixture.
In this Invention the above conditions are provided for by a combustion
apparatus, consisting of alternate gas and air ports, and an arch or diaphragm so
placed over them as to throw together the jets issuing from the said ports, and
form a hot chamber in which the gases are mixed, ignited, and burned in contact
with hot walls before reaching the comparatively cool boiler surfaces.
And in order that the said Invention may be more clearly understood and
readily carried into effect, I will proceed, aided by the accompanying Drawings,
Figure 1 is an elevation of a return tube boiler P, and a longitudinal vertical
section of the combustion chamber W, and of the gas burner on the broken line
3-3, Figure 3.
Figure 2 is a vertical cross section of the same..
Figure 3 is a horizontal section of part of the gas burner and part of the com-
bustion chamber on the broken line 1, 1, Figure 1.
The same letters refer to the same parts in all the Figures.
The flue E extends under the boiler and conveys gas to the burner from any
suitable gas producer. The flue H conveys air to the burner. These flues may
enter from the front or rear or side of the apparatus, and the flow of gas and air
through them must be regulated by valves in any suitable manner known to the
users of ordinary gas furnaces.
The burner consists of a series of alternate gas ports G, G, and air ports A, A,
in the floor of the combustion chamber. The gas ports G receive gas from the gas
Hue E by means of slits M, M, in the inner side wall of the said gas flue. The air
ports A communicate with the air flue H by means of similar slits L
The combustion chamber W is formed by the side walls R and walls S, K, of the
furnace, or by any suitable refractory walls adapted to the kind of boiler used, and

page_text: of a brick or mineral roof F, which is so arranged as to cause the gas and air jets
from the ports A, A, G, G, to mingle in their passage toward the boiler; also to
give an ample space for combustion; also to throw the hot gaseous products of
combustion against the part of the boiler where the fire box would ordinarily be
situated.
When the walls of the combustion chamber are once heated to a temperature
sufficient to ignite the combustible mixture of air and gas, the said mixture is
ignited as fast as formed, and is more or less completely burned in the chamber.
It is not practically essential that the whole of the combustible mixture should be
burned in the chamber; a part of it, when once lighted, will burn nearly com-
pletely in passing over the top of the combustion chamber. It is essential to
economical combustion that a chamber interposed between the air and gas ports
and the boiler should promote the mixture, ignition, and combustion of the air
and gas.
The sizes of air and gas ports and flues must depend on the amount of gas to be
burned. The common gas furnace practice affords sufficient data on this subject.
These sizes may be made smaller in proportion to the pressure at which the air and
gas enter the burner.
It is obvious that the ports may be placed much nearer together, and that several
rows of ports may be employed in order to more quickly mix the air and gas. It
is found, however, that the burner shown in the Drawings, which may be cheaply
built of ordinary fire bricks and tiles, is durable and effective.
The regenerative system may be applied to this apparatus by pre-heating the air
or gas, or both, in passages formed in the walls of the combustion chamber, or by
any of the ordinary methods.
Having thus described the nature of the said Invention and the mode in which
the same is carried into effect, I would have it understood that what I claim is,―
First. The air and gas mixing apparatus consisting of the ports A, G, and the
diaphragm F so placed over them as to throw together the jets issuing from said
ports.
Second. In a gas furnace for steam boilers, the combustion apparatus consisting
of the alternate ports A, G, and the diaphragm F so placed over them as to throw
together the jets issuing from said ports, and to forin a hot chamber W for igniting
and burning the mixture, substantially as described.
In witness whereof, I, the said Benjamin Joseph Barnard Mills, have hereunto
set my hand and seal, this Twenty eighth day of July, in the year of
our Lord One thousand eight hundred and eighty one.
D.
B. J. D. MILLS.
(L.S.)