An Improved System of Inducing Combustion for Generating Steam in Boilers and Heating and Re-heating in Furnaces, and in Apparatus and Furnaces Employed therein.
Year: 1889

page_text: Date of Application, 26th Nov., 1889
Complete Specification Left, 26th Sept., 1890-Accepted, 24th Dec., 1890
PROVISIONAL SPECIFICATION.
An Improved System of Inducing Combustion for Generating Steam
in Boilers and Heating and Re-heating in Furnaces, and in
Apparatus and Furnaces Employed therein.
I JAMES HARGREAVES of Farnworth in Widnes in the County of Lancaster Chemical
Engineer, do hereby declare the nature of this invention to be as follows:-
The object of my invention is to ensure combustion of coal and other fuel at such
point or points as the heat is required of higher pyrometrical efficiency than has been
possible hitherto, superseding in short regeneration of gas and air and preventing
escape of black smoke into the atmosphere.
For this purpose I supply measured quantities of fuel and air to a small producer
placed near the boiler or hearth to be heated.
The proportions of air and fuel will be varied with the nature of the fuel and also
with the temperature and barometric pressure of the atmosphere according to well
known laws, and the proportions will also be varied with the character of the flame
required. For instance with air of 30 inches barometric pressure, and 60 degrees of
Fahrenheit and ordinary coal I employ 120 to 140 cubic feet of air for the combustion
of each pound of coal where a reducing flame is required such as in puddling furnaces
during the balling process, or in reheating furnaces where it is desirable to reduce
metallic oxides or prevent oxidation of the metal.
When a neutral flame is required I use about 150 cubic feet of air to each pound of
coal.
An oxidizing flame for use say in pyrites and other ores 160 and upwards of cubic
feet of air are required to every pound of coal.
With these proportions or thereabouts and the maintenance of pressure in the flue
or furnace or over the hearth and at the outlet I. effect the above mentioned desired
result.
Where a reducing flame is necessary I add air to the products after passing through
the furnace whereby the suspended carbon in the products of combustion is burned
into carbonic acid.
I prefer to form the bottom of the said small producer of a plate or grid of metal
with small apertures preferably conical in form. The air is forced below the said
perforated plate through the apertures and through the fuel placed thereon, and there
is no necessity for stoking or levelling the fuel, inasmuch as while combustible gas is
given off at one portion of the said producer a sufficient excess of air passes through
another portion to effect combustion.
The space below the said perforated plate is provided with an air tight door or
doors to provide for the extraction of any ashes which may fall through the perfora-
tions in the said plate. There is also provided an air tight door or doors through
which any accumulation of ashes or scoria may be extracted. To protect from injury
the said air tight door in the body of the said producer, 1 insert fire brick or other
suitable blocks.
When the said system of combustion is employed in heating boilers I use such a
proportion of air as shall produce a neutral or slightly oxidizing flame, and prefer to
place the producer outside the boiler Blues or with such an amount of slowly conducting
lining as shall protect the boiler plates from the very intense temperature.
The apparatus which I use for supplying measured quantities of fuel to the said
producer consists of a plate with perforations or cavities of any desired size. The
said perforated plate passes below a hopper containing the coal or other fuel, whereby
the said perforations or cavities are charged, and the excess of fuel above the said

page_text: cavities is scraped off by passing from under the edge of the said hopper. The said
plate then carries the said fuel to a suitable opening whereby the said fuel is allowed
to fall into the said producer But it will be clear that the fuel may be supplied by
or through many modifications of apparatus.
The machine which actuates the supply of fuel prefer to connect to the blower or
pump which supplies the air and this in such manner that as the supply of air is varied
so is the supply of fuel varied in the required proportion.
When a varying quality of flame is required, such as in puddling furnaces, where
at one time a reducing flame and at others an oxidizing flame is necessary I provide
regulators and measurers for varying the relative proportions of air and fuel.
Dated this Twenty-fifth day of November 1889.
COMPLETE SPECIFICATION.
An Improved System of Inducing Combustion for Generating Steam
in Boilers and Heating and Re-heating in Furnaces, and in
Apparatus and Furnaces Employed therein.
I JAMES HARGREAVES of Farnworth in Widnes in the County of Lancaster, Chemical
Engineer 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 :-
The object of my invention is to ensure combustion of coal and other fuel at such
point or points as the heat is required of higher pyrometrical efficiency than has been
possible hitherto, superseding in short regeneration of gas and air and preventing
escape of black smoke into the atmosphere.
For this purpose I supply measured quantities of fuel and air to a small producer
placed near the boiler or hearth to be heated.
The proportions of air and fuel will be varied with the nature of the fuel and also
with the temperature and barometric pressure of the atmosphere according to well
known laws and the proportions will also be varied with the character of the flame
required. For instance with air of 30 inches barometric pressure and 60 degrees of
Fahrenheit and ordinary coal I employ 120 to 140 cubic feet of air for the combustion
of each pound of coal where a reducing flame is required such as in puddling furnaces
during the balling process, or in reheating furnaces where it is desirable to reduce
metallic oxides or prevent oxidation of the metal.
When a neutral flame is required I use about 150 cubic feet of air to each pound
of coal.
For an oxidizing flame for use say in pyrites and other ores 160 and upwards of
cubic feet of air are required to every pound of coal.
With these proportions or thereabouts and the maintenance of pressure in the flue
or furnace or over the hearth and at the outlet I effect the above mentioned desired
results. Where a reducing flame is necessary I add air to the products after passing
through the furnace whereby the suspended carbon in the products of combustion is
burned into carbonic acid. I prefer to form the bottom of the said small producer of
a plate or grid of metal with small apertures preferably conical in form. The air is
forced below the said perforated plate through the apertures and through the fuel
placed thereon, and there is no necessity for stoking or levelling the fuel, inasmuch
as while combustible gas is given off at one portion of the said producer a sufficient
excess of air passes through another portion to effect combustion. The space below
the said perforated plate is provided with an air tight door or doors to provide for
the extraction of any ashes which may fall through the perforations in the said plate.
There is also provided an airtight door or doors through which any accumulation of
ashes or scoria may be extracted. To protect from injury the said airtight door in
the body of the said producer, I insert fire brick or other suitable blocks. When the

page_text: said system of combustion is employed in heating boilers I use such a proportion of
air as shall produce a neutral or slightly oxidizing flame, and prefer to place the
producer outside the boiler flues or with such an amount of slowly conducting lining
as shall protect the boiler plates from the very intense temperature. The apparatus
which I use for supplying measured quantities of fuel to the said producer consists of
a plate with perforations or cavities of any desired size. The said perforated plate
passes below a hopper containing the coal or other fuel, whereby the said perforation
or cavities are charged, and the excess of fuel above the said cavities is scraped off by
passing from under the edge of the said hopper.
The said plate then carries the said fuel to a suitable opening whereby the said fuel
is allowed to fall into the said producer, but it will be clear that the fuel may be
supplied by or through many modifications of apparatus. The machine which
actuates the supply of fuel I prefer to connect to the blower or pump which supplies
the air and this in such a manner that as the supply of air is varied so is the supply
of fuel varied in the required proportion.
Where a varying quantity of flame is required, such as in puddling furnaces, where
at one time a reducing flame and at others an oxidizing flame is necessary, I provide
regulators and measurers for varying the relative proportions of air and fuel.
The accompanying drawing is a vertical section of apparatus under my invention
for inducing combustion a are the walls of a small producer placed near the boiler
or hearth to be heated, is the combustion space, c is a perforated plate or grid
forming the bottom of the pro lucer and upon which the fuel rests, d is an ashpit,
e are airtight doors to the ashpit and combustion space to allow of removal of ashes.
fis a pipe through which air is forced by the blower g into the ashpit and then
through the perforated plate c amongst the fuel resting thereon. h is a hopper for
containing the fuel to be introduced into the producer, is a revolving plate actuated
by the worm and wheel j and provided with pockets or cavities k into which fuel from
the hopper h falls. By the revolution of the plate i the pockets and the fuel therein
are successively brought over an opening or way through which the fuel falls into
the producer, m is a passage leading from the producer to the boiler, hearth or other
place where the heat generated is to be utilized, n is gearing connecting the blower
with the worm so that the air and fuel are delivered to the producer in the proper
proportions to obtain the desired effect. The gearing n is preferably made with change
wheels, or other appliances for varying the rates of speed so that the proportions of
fuel and air delivered to the producer may be varied according to the quality of flame
required, or to compensate for differences of temperature and barometric pressure of
the air passing through the gas measuring apparatus.
I do not confine myself to a revolving fuel measurer as herein described, as a
reciprocating or other suitable measuring apparatus may be used.
Neither do I confine myself to completing the combustion within the producer
itself, as a portion of the air may be allowed to flow into another chamber or space
and there complete the combustion of the imperfectly burnt gases given off by the
said producer.
For instance in firing boilers I prefer to complete the combustion at once by adding
the necessary quantity of air in the producer.
In heating reverberatory furnaces I prefer to add about half the air in the producer
and the rest in the body of the furnace, so as to complete the combustion of the
gases from the producer at the point where the heat is to be utilized. This may be
carried into effect by many obvious means.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is:
__
First. Inducing combustion by the injection of air and fuel in measured quantities
into a producer substantially as described.
Second. The combination of fuel and air feeding and measuring apparatus substan-
tially in the manner and for the purpose set forth.

page_text: Third. Constructing producers for use with fuel and air feeding apparatus substan-
tially in the manner and for the purpose set forth.
Dated the Twenty-fifth day of September 1890.
Per pro J. T. KING,
J. Johnson,
Agent.