CONSUMING THE SMOKE AND GASES OF FURNACES, AND AT THE SAME TIME FURNISHING A HOT-AIR BLAST, BEING A SMOKE AND GAS-CONSUMING HOT-AIR BLAST FURNACE
Year: 1857

page_text: LETTERS PATENT to Charles Barlow, of the Office for Patents, 89, Chancery
Lane, London, for the Invention of "CONSUMING THE SMOKE AND GASES
OF FURNACES, AND AT THE SAME TIME FURNISHING A HOT-AIR BLAST, BEING
A SMOKE AND GAS-CONSUMING HOT-AIR BLAST FURNACE." - A cominuni-
cation from Thomas Aldridge, of the City of Hudson, Jersey, United
States
Sealed the 13th October 1857, and dated the 13th April 1857.
PROVISIONAL SPECIFICATION left by the said Charles Barlow at the
Office of the Commissioners of Patents, with his Petition, on the
13th April 1857.
I, CHARLES BARLOW, of the Office for Patents, 89, Chancery Lane, London,
do hereby declare the nature of the said Invention for "CONSUMING THE SMOKE
& GASES OF FURNACES, AND AT THE SAME TIME FURNISHING A HOT-AIR BLAST
BEING A SMOKE AND GAS-CONSUMING HOT-AIR BLAST FURNACE," a communica-
tion from Thomas Aldridge, of the City of Hudson, State of New Jersey,
United States, to be as follows:-
It cousists in the application & use of a new and improved method of
transferring the smoke and gases of furnaces from the chimney or smoke
stack to the furnace, and in such a manner that they will be most effectually
[Price 8d.]

page_text: and economically consumed, and in mixing therewith a continual supply of
heated atmospheric air for the purpose of changing its character, so as to
become a better supporter of combustion, and effecting this before the
smoke & gas comes in contact with the fire, & by this whole operation
securing also a constant hot-air blast for any such furnace.
To the chimney or smoke stack of a furnace, and upon either side as most
convenient, though I deem the most preferable that side opposite or nearest
opposite the furnace, and at or near the part or place where the smoke and
gases enter after they pass from contact with the boilers, is attached a large
pipe or conductor, the other end of which enters or opens into the front part
of the furnace and under the fire or grate bars, such pipe being close, and the
doors into the furnace and ash-pits being also kept closed all the time. To this
pipe and near the chimney is attached a blower of sufficient capacity to draw
the smoke, &c. from the chimney and force it through such pipe and under
the fire, and which may be driven by the engine or any convenient power.
I am aware that efforts have been made to consume the smoke & gases of
furnaces, and that some have been partially successful, but such, so far as I
can learn, attempt to confine or keep back the smoke, gas, &c., on top of the
fire by inverted arches of some contrivance for the same purpose, where it
shall be retained and burned; whereas my Inventions takes all these from the
chimney and carries them to and feeds them under the fire, through which they
naturally ascend, and by which they are consumed. In order to keep up a
supply of oxygen for the purpose of increasing heat and combustion, there is
a tube or pipe, one end of which is open to the atmosphere, and which passes
by or near the boiler, so that the air in it will be completely heated, and the
other end of which enters the smoke conductor between the chimney and
the blower, so that the draft of the blower shall cause a constant renewal of
such atmospheric air. As it is known, the principal gas evolved from the
consumption of coal is carbonic acid gas, which is by itself not a supporter of
combustion; by mixing, however, with this gas atmospheric air, the nitrogen
of the atmosphere unites with the carbonic acid gas and produces an
inflamable gas. By causing, therefore, the atmospheric air to be mixed with
the gases drawn from the chimney, and at such a point that these can be well
mixed and combined before they reach the fire, we secure as supporters of
combustion, in addition to the smoke, which is principally small particles
of coal, and besides the oxygen which is found in the atmosphere, another
inflamable gas, which is made up of two gases, cach of which is a non-sup-
porter of combustion when uncombined with the other. The supply of such
gas will necessarily depend somewhat upon the perfectness of mingling and

page_text: .
combination. When the smoke and gases are held or kept back on top of
the fire, even if atmospheric air is admitted there, the union cannot be very
complete, because the natural draft alone would be unfavourable both for
such combining as well as to their retention there for the purpose of being
consumed. When, however, they are mixed and united, as described,
before they reach the fire, the greatest possible quantity of supporters of
combustion will be produced, all of which will be also, as before stated, fed
under the fire, and where they will most effectually support combustion,
and also render unnecessary any device for keeping them in contact with
the fire. The admission of these gases under the fire gives also a like high
temperature to every part of the fire and prevents the formation of clinkers,
et id omne genus, as these are produced from melting and running together,
all of which is prevented, the constant incoming of these gases burning the
coal and not melting it. This also produces a more complete consumption
of the fuel, and thus saves cost.
As will be apparent, the draft of the fire will not depend upon the form or
elevation of the chimney, the expense of which may be saved, but upon the
speed of the blower, & the power with which the smoke and gases are
supplied to the fire. This draft, or the speed of the blower, is therefore
regulated by the pressure of the steam in the boiler, the velocity and draft
increasing as the pressure falls below the required standard, and vice versa,
thus rendering my Invention self-adjusting or automatic, and to any pressure
wished. This I accomplish by the use of two conical pulleys, one of which is
worked from the engine, and the other operates the blower, these pulleys being
connected by a belt. This belt is moved on these conical pulleys, and thereby
the velocity of the blower increased or diminished by a strap stick, worked by
a series of levers, which are moved by the rising or falling of a piston in a
small cylinder, to which steam is admitted by a pipe connecting with the
boiler, and the action of which piston may be regulated or graduated accord-
ing to any required pressure. As the pressure increases the piston will be
raised, and the belt, by means of the levers, &c., will be moved to a smaller
part of the pulley worked by the engine, and to a larger part of the opposite
one, thus decreasing the speed of the blower and lessening the draft; but as
the pressure diminishes, a contrary movement takes place, increasing the
velocity of the blower and increasing the blast or draft.
The general character of my Invention therefore consists in an improved
method of consuming the smoke and gases of furnaces, by taking them from
the chimney near where they enter it, thus losing but little or any, and in
mixing and combining therewith heated atmospheric air, & thereby pro-

page_text: ducing a new element, which is also a supporter of combustion, and in
producing this combination and mingling bofore these substances come in
contact with the fire, and in feeding all these under the fire, thus rendering
their combustion most complete; and also effecting the same in the most
economical manner, and securing the greatest amount of heat therefrom, and
in regulating the action of my Invention, & consequently the draft of the
furnace, by the pressure of steam in the boiler decreasing the draft as the
pressure becomes too great, and increasing it as the pressure falls too low,
thus rendering the whole automatic and solf-adjusting.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Barlow in the Great Seal Patent Office on
the 13th October 1957.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
BARLOW, of the Office for Patents, 89, Chancery Lane, London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of April, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Charles Barlow, Her special licence that I, the said Charles Barlow, my
executors, administrators, and assigns, or such others as I, the said Charles
Barlow, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "CONSUMING THE SMOKE AND GASES
OF FURNACES, AND AT THE SAME TIME FURNISHING A HOT-AIR BLAST, BEING A SMOKE
AND GAS-CONSUMING HOT-AIR BLAST FURNACE," a communication from Thomas
Aldridge, of the City of Eludson, Jersey, United States, upon the condition
(amongst others) that I, the said Charles Barlow, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that 1, the said Charles Barlow, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being also had to the accompanying
Drawings, and to the letters of reference marked thereon, and making a
part of this Specification:-
The nature and object of the said Invention consists in the application
and use of a new and improved arrangement and combination of mechanism,
by means of which the smoke and gases that generally pass off through
the chimnoy and are lost are withdrawn froin the chimney or smoke flue
thoroughly mixed and incorporated with abundant supplies of highly-heated
atmospheric air, so as to promote their complete combustion, and then to
and forced under and through the fire or furnace, where they will be
effectually consumed, thereby economising fuel and obtaining a greatly
increased amount of heat, and also securing a constant hot-air blast, and in
rondering the whole arrangement of the mechanism self-adjusting by and
according to the pressure of steam in the boiler.
Fig. 1 is a perspective view of an ordinary tubular boiler and furnace
with the Invention or improved arrangement attached thereto, and shewing
also the manner of rendering the same self-regulating according to the
pressure of steam in the boiler.
Fig. 2 is a more particular view of the mechanism by which the Invention
is made self-adjusting or automatic by means of steam in the boiler and
according to any desired pressure of it.
In the various Inventions which have been heretofore made and used to
effect the combustion of the smoke and gases of furnaces, the arrangement has
usually been to retain and confine these on top of the fire untill they could be
cor sumed, thus, in fact, making the furnace a closed furnace, and therefore
rendering sono means to facilitate combustion retarded by their continued
pressure on top of the fire, and the pressure of which would of course some-
what interfere with or check the natural or needed draft of the fire. In those
cases in which it has been sought to carry the smoke, &c. under the fire, the
action has been very imperfect, and the results generally unsatisfactory.
All such objections are obviated by this Invention, while its action is
uniform and complete, effecting the entire combustion of the smoke, and
at the same time increasing, and, in fact, creating the draft of the furnace,
which draft is also rendered automatic or self-adjusting according to the
pressure of steam, that is, the draft is increased or diminished as the pressure
falls below or exceeds any given standard.

page_text: Its construction and operation, as illustrated by the Drawings, nre as
follows: When attached to a differently arranged boiler its construction
will vary somewhat, but the principle of its operation will be the same. A is
an ordinary cylinder boiler, set in a foundation B, and the chimney and
smoke stack being at the rear end of the boiler, and in the case represented a
little at one side of the boiler. Dis the furnace door, and E the door to the
ash-pit underneath the fire; these are constructed in any of the ordinary
ways, there being nothing peculiarin respect to them. To the chimney orsmoke
stack, at or near the point or level at which the smoke and waste gases of the
fire enter it and cease to act upon the boiler, is connected or inserted a tube, or
smoke and gas conductor F, the other end of which opens into the ash-pit or
underneath the grate. In constructing now furnaces, or when it can be done
in the alteration of old ones, it will be advisable to place this conductor within
the foundation of the boilers and thus underneath them, and opening under
the fire through the bridge wall, so that any heat which shall radiate from this
conductor shall not be lost, but will act upon the boilers, and thus be effective;
or this conductor may be metallic, and may be caused to pass through the
steam chamber, or a steamn chamber provided for the purpose, and thus be
rendered highly effective for the purpose of superheating steam; or it may,
and this will most likely be the case when the Invention is to be attached
to furnaces and boilers already built and set and in use, be placed outside
tho work supporting the boilers, &c. It may also be made of iron, wood, or
brick, but when outside should be made of materials which are the best non-
conductors of heat, or protected by non-conductors. It may also be connected
to either side of the chimney or smoke stack most convenient in any particular
case, though generally it will be best to have the connection as high as, or
perhaps, some little above, the entrance of the direct flue into the chimney.
When the boilers do not extend to the chimney or smoke stack, and a flue is
used to conduct the products of combustion to the chimney or smoke stack,
the conductor F should connect with such flue at or near the point where the
smoke, heat, &c. cease to affect the boilers; such conductor may of course be
accommodated in shape and position to the circumstances of any particular
case, but sharp angles should be avoided when possible, and care should be
taken to connect it to the chimney or smoke stack or flue at or near the point
or place where the smoke, gases, &c. cease to act upon and affect the boilers,
and that the other end open under the furnace or grate bars.
To the conductor F is connected or attached a blower G, the exact location
of which is not material, except that it is well to place it near the chimney
or flue, where the conductor F connects therewith, so as to draw more com-

page_text: pletely the smoke, gases, &c. from the chimney or flue to ensure their more
perfect combustion. The construction of this blower is not material, except
that the receiving orifice through which the smoke and gases are taken from
the chimney or flue, and the discharge orifice through which they are driven
toward the fire, should be large, and as long as the fans, so that there shall be
no obstruction to the free entrance and exit of these substances. The blower
now used has these orifices on its opposite sides, the former being nearer the
top and the latter nearer the bottom, and with other orifices on the other
sides to receive atmospheric air, as hereafter mentioned. When wished, for
any purpose, the conductor F in front of the blower may be divided, and
the smoke, &c. be delivered at different points under the furnace or under
different furnaces. The size of the blower will also vary according to the
size of the furnace, and the fuel consumed. The action of this blower is to
continually draw the smoke, gases, &c. from the smoke stack or flue, and
prevent any escaping therefrom, and force then through the conductor F
and under the fire, in passing through which every thing combustible or
inflamablo is consumed or rendered useful, thereby economizing fuel and
increasing heat. The furnace and ash-pit doors are kept tightly closed to
prevent any air entering through them.
In order, however, to ensure economy and effect in the combustion of fuel
a large and copious supply of air is necessary, and as "perfect combustion "
has been defined to be "the prevention of smoke," the supply of air necessary
in such quantity as will render the products of combustion transparent or
"smokeless." An insufficient supply of air causes incomplete combustion,
and a consequent waste of a great part of the heat evolved from or by the fuel.
Such supply of air is secured by means of an atmospheric air pipe, the mouth
of which is seen at H, and the other end of which enters the blower, or the
conductor F between the blower and the chimney or flue. This pipe should
be large enough to furnish the air requisite, and its size will be determined
from the quantity of gases, &c. produced from combustion, and the quantity
of air according to the best authorities required for their combustion. This
pipe should, however, be made amply large enough, and its mouth may be
regulated by a door 1. As this pipe connects with the blower, or the conductor
ucar the blower, the action of the blower is to create and continue a constant
suction or draft of atmospheric air through it, and into the conductor F, as
well as to draw the smoke from the chimney.
The combustion of fuel, and particularly coal, as is well known, produces
large quantities of carbonic acid and carbonic oxide, the latter of which is
formed by the carbonic acid passing over the intensely ignited coal of the

page_text: furnace, a portion of which it takes up, and if the carbonic acid could be
retained sufficiently long in contact with the heated coal it would be wholly
converted into the oxide. Carbonic oxide is, however, unlike carbonic acid,
inflamable, and in burning gives out a large amount of heat. In ordinary
furnaces this gas passes off through the chimney, carrying with it a great pro-
portion of the heat it should give out if the coal had been burned with a due
supply of air. By the arrangement before described, this gas, together with
the other products of combustion, is prevented from escaping. As, however,
gases do not rapidly mix with each other, and as it is necessary for the pur-
poses of combustion in a furnace that such union should be effected with great
rapidity, and as the union of gases is rather mechanical than a chemical
afinity, it is very desirable and necessary that the smoke aud gases drawn from
the chimney should be thoroughlyand intimately mixed with the atmospheric
air, and that such mingling should be effected before these clements are
brought in contact with the fire. This desirable result is accomplished by
causing the atmospheric air tube to open into the blower case, or into the
conductor F between the blower and the chimney or flue, so that the smoke
and gases drawn from tho chimney or Hue and the air shall be together sub-
jected to the action of the blower, and thus be completely and thoroughly
mixed and united, and that before they reach the furnace or fire. Iu
order, however, that the temperature of the fire may not be reduced by the
constant supply of such quantities of atmospheric air as are necessary for the
consumption of the products of combustion, the atmospheric air pipe is so
placed in respect to the fire or flues of the furnace, that the air passing through
it will be thoroughly and highly heated before it reaches the blower or con-
ductor, as above described. By this arrangement the introduction of the
required quantity of atmospheric air is prevented from acting at all as a cold
blast, but is made in reality a hot blast, and if more air happens to be admitted
than is required for the perfect combustion of the gases,&c., the surplus is in
effect an additional heating element, which instead of taking up the heat of
the fire will impart its heat to it. The heating of the atmospheric air secures.
also another very desirable effect and result, in that it causes a more complete
union or combination of the carbon and oxygen, which have but little afinity
for each other at ordinary temperatures, but a very strong afinity when they
are raised to high temperatures. In order to so heat the atmospheric air
supplied, the tube or vessel by which it is conveyed to the blower may, as is
represented in the Drawing, enter into the direct flue and pass along through
it, as is shewn by the dotted lines, and from thence into the blower, or it may
be placed in any other position as to the flues and boiler so that the air will

page_text: be heated. Such pipe may also be caused to pass through any heated place
or apartment seperate from the boiler, and with the same end secured. As
before remarked, the position of such air tube or vesselis immaterial, provided
it be so arranged that the air passing through it will be thoroughly heated,
and that it connects with the blower, or the conductor F between the blower
and the flue. When, therefore, desirable, the waste steam may be caused to
pass through a series of tubes surrounded by the air, and in this manner the
air may be heated, and without absorbing any of the heat of the furnace. By
this method, also the steam will be condensed,and the water derived therefrom
can be supplied again, and with a high temperature to the boilers; and
generally any method most convenient under the circumstances of any
particular case for heating the air may be made use of.
As will be apparent also from the foregoing description, the draft of the fire
will depend upon or rather is produced and governed by the action and velocity
of the blower referred to, and is not to any extent created or affected by the
form or height of the chimney or smoke stack. An ordinary chimney is
therefore all that is necessary to carry off the small amount of hot air, &c.
which will pass off, and the expense of constructing tall and costly chimneys
may, for the reason stated, be saved.
The practical operation of thisInvention willbeapparent from the following
facts. The damper of the chimney is kept almost wholly closed, & but very
little if any smoke is seen to rise from the chimney even when soft coal is
burned, except for a minute or so, when the furnace doors are opened and
fresh fuel thrown upon the fire. Previous to the application of the Invention
to a furnace and boilers, the brick foundation supporting the boilers was only
moderately heated, while the chimney for some distance up was hot, thus
shewing the passage through it of a great amount of heat. And such is the
situation and, condition of furnaces and chimneys as ordinarily constructed.
With the use however of this Invention the chimney is but slightly heated,
while the foundation of the boilers becomes hot, proving that the heat is
retained and made effective where it should be under the boilers. Careful
& extended experiments has also shewn that by the application and use of
this Invention to a furnace and boilers and engine full thirty por cent. of
fuel is saved, and that while using the same kind of fuel and performing the
same amount of work. By using an inferior kind of coal, that is, pea coal
and coal dust, the saving is much greater.
To render the Invention self-adjusting or automatic, the speed of the,con-
sequently the draft of the fire is regulated by and according to any required
pressure of steam in the boiler. This may be effected by means of the.

page_text: following arrangement of mechanism, or any other securing the same end.
From the boiler A a steam pipe J connects with or under a small cylinder
K, placed where convenient, in which works loosely a flcat and piston L,
which float rests upon a strong piece of vulcanized rubber, fastened between
the bottom of the cylinder and the foundation K, on which it rests,and which
by its elasticity will allow of all necessary movement to the piston L. The
lever M. resting upon L is loaded to correspond to any required pressure of
steam in the boiler. The long arm of such lever connects by means of the
short bar O with the elbow or bent lever P, working on the pivot p, which
lever is fastened to the strap stick frame a,a,which plays between the conical
pulleys Q, Q, carrying or moving by means of the links c, c, the band b, b.
The conical pulleys are so placed that their largest and smallest diameters
are opposite each other, one having a fast and loose pulley, over which plays
a belt from the engine or any motive power, and the other pulley carrying
a belt R, working the blower G. When tho pressure of the steam in the
boiler exceeds the given standard, the lever L will be raised, and through its
connections move the strap stick, and slide the belt b,b,to a smaller diameter
of the conical pulley worked by the engine, and to a larger diameter of the
other. and thus diminish the velocity of the blower and the draft of the fire.
When the steam, on the other hand, falls below the given standard, a contrary
motion of the several parts will take place, and the belt be carried to a
smaller diameter of the conical pulley Q', and increase the velocity of tho
blower and the draft of the fire. The practical oporation of this arrange-
ment is very perfect, & most highly satisfactory in its effect.
It is not claimed that it is new to bring the smoke and products of com-
bustion from the chimney and carry them under the furnace by means of
a blower, and either with or without orifices in the blower case, for the
admission of air at its ordinary temperature, neither is it generally claimed
that the use of heated air to assist combustion is new, as this is found in tho
ordinary hot-blast furnaces; but what is claimed as new is, the arrangement
or combination of the pipe or vessel or conductor H, or its equivalent, sub-
stantially as set forth and described, with the blower G and flue or conductor
F, conveying the smoke, &c. to the furnace, so as to furnish an abundant
supply of air to the products of combustion, and to be mixed therewith by
the blower before they are taken to the fire; and also placing such pipe or
vessel H, or its equivalent, in or connecting it with any heated apartment or
locality, or heating apparatus,for the purpose of highly heating the air supplied
by to the products of combustion and mingled therewith, as and for the
purposes set forth. And also, in combination therewith, regulating the

page_text: velocity of the blower, as described, or in any equivalent manner, by and
according to the pressure of steam in the boiler, so as to increase or
decrease the draft of the fire as necessary and automatically.
In witness whereof, I, the said Charles Barlow, have hereunto set
my hand and seal, the Tenth day of October 1857.
CHARLES BARLOW. (L.S.)