IMPROVEMENTS IN STEAM BOILERS AND FURNACES, AND IN APPARATUS CONNECTED THEREWITH, AND IN THE CON- SUMPTION CR PREVENTION OF SMOKE."
Year: 1856

page_text: LETTERS PATENT to David Auld, of the City of Glasgow, in the County of
Lanark, North Britain, Engineer, and John Stephen, of the same Place,
Mill Manager, for the Invention of "IMPROVEMENTS IN STEAM BOILERS
AND FURNACES, AND IN APPARATUS CONNECTED THEREWITH, AND IN THE CON-
SUMPTION CR PREVENTION OF SMOKE."
PROVISIONAL SPECIFICATION left by the said David Auld and Jolin.
Stephen at the Office of the Commissioners of Patents, with their Petition,
on the 20th February 1856.
We, DAVID AULD, of the City of Glasgow, in the County of Lanark, North
Britain, Engineer, and JOHN STEPHEN, of the same Place, Mill Manager, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN STEAM
BOILERS AND FURNACES, AND IN APPARATUS CONNECTED THEREWITH, AND IN THE
CONSUMPTION OR PREVENTION OF SMOKE," to be as follows, that is to say:
This Invention relates to the so arranging steam boilers, that they may be.
worked with both external and internal fires and flues in combination, the,
object being the obtainment of, superior concentration of boiler or steam
power, the economy of fuel, and the prevention of smoke.
In applying the Invention to a cylindrical steam boiler, the boiler shell is so
mounted that its lower side comes to be about level with the floor line of the
boiler house. An external furnace or fire-place is formed in a suitable recess
[Price Sd.]
'

page_text: beneath this level, and the smoke and heat current therefrom passes
directly beneath the boiler to the back or further end, along a suitable
bed flue formed in the brickwork of the boiler seat. Above the level of
this external furnace, and inside a flue running directly through the boiler
longitudinally, there is a second but internal furnace arranged in the
general manner hitherto adopted in boilers with internal fires. The gaseous
current from this internal fire traverses the entire length of the internal
boiler flue, and on reaching the back end, the current joins and mingles
with that from the external furnace. The combined current then turns
back, and divides into two portions, one returning along two external
flue passages formed between the lower part of the external surface of the
boiler shell and the internal surface of the seating brickwork. In this way,
the two currents pass to the front or furnace end of the boiler, when they
return again to the back or chimney end through two higher external flues,
and proceed thence to the chimney. These higher external flues may be at
such a level that the gaseous current passing through them may heat the
steam in the steam portion of the boiler above the water, and thus surcharge
or superheat and dry the steam as fast as it is generated. The external and
internal furnaces are fired alternately, so that the crude unconsumed gaseous
products from one fire are consumed and turned to economical account
by passing through the flame and more highly heated current of the other.
Instead of a single internal furnace and flue, the boiler may be made with
two parallel furnaces. These furnaces have their flues so arranged that their
gascous currents combine in a combustion chamber at or near the bridge.
This combined current subsequently diverges into two separate currents,
which pass to the back end of the boiler, and then join, traversing the flues
in conjunction with the external furnace current, as herein-before described.
To ensure regularity and certainty in the smoke consumption or prevention,
an automatic air supply valve is fitted up in the front or end of the boiler,
mounting and communicating with an air channel passing to a hollow in the
bridge, or to some other point at or near the bridge. This air valve is con-
nected with a steam pressure regulating apparatus, such as that for which
Mr. David Auld has already obtained British Letters Patent, or modifications
of such apparatus. When the steam pressure, as indicated by such apparatus,
falls, and it becomes necessary to fire, the connection with the pressure
apparatus causes the air valve to be opened, so that as fresh coal is sup-
plied, air is admitted to aid the combustion and consume the gaseous
products.

page_text: A
By another arrangement, provision may be made for effecting the satis-
factory supply of the boiler with feed water in an economical manner.
float is fitted up inside the boiler, and as the water level falls, the descent of
this float is made to admit steam from the boiler to work a pair of small or
"donkey" engines, which continue to pump water into the boiler, until the
ascent of the float causes the actuating steam to be shut off.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Auld and John Stephen in the Great Seal Patent
Office on the 20th August 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, DAVID
AULD, of the City of Glasgow, in the County of Lanark, North Britain,
Engineer, and JOHN STEPHEN, of the same Place, Mill Manager, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
l'atent,bearing date the Twentieth day of February, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto us, the said
David Auld and John Stephen, Her special license that we, the said
David Auld and John Stephen, our executors, administrators, and assigns,
or such others as we, the said David Auld and John Stephen, our execu-
tors, administrators, or assigns,should at any time agree with, and no others,
from time to timeand at all times thereafter during the term therein expressed,
should and lawfully might make, use, excrcise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN STEAM BOILERS AND FURNACES, AND
IN APPARATUS CONNECTED THEREWITH, AND IN THE CONSUMPTION OR PREVENTION OF
SMOKE," upon the condition (amongst others) that we, the said David Auld and
John Stephen, by an instrument in writing under our 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.
NOW KNOW YE, that we, the said David Auld and John Stephen,
do hereby declare the nature of our said Invention, and in what manner

page_text: the same is to be performed, to be particularly. described and ascertained in
and by the following statement in writing, reference being had to the
accompanying Drawings, and to the letters and figures marked thereon,
that is to say:-
Our said Invention relates to the so arranging steam boilers, that they
may be worked with both external and internal fires and flues in combination,
the object being the obtainment of superior concentration of boiler or steam
power, the economy of fuel, and the prevention of smoke.
In applying the Invention to a cylindrical steam boiler, the boiler shell is so
mounted that its lower side comes to be about level with the floor line of the
boiler house. An external furnace or fire-place is formed in a suitable recess
beneath this level, and the smoke and heat current therefrom passes directly
beneath the boiler to the back or further end along a suitable bed flue formed
in the brickwork of the boiler seat. Above the level of this external furnace,
and inside a flue running directly through the boiler longitudinally, there is a
second but internal furnace arranged in the general manner hitherto adopted
in boilers with internal fires. The gascous current from this internal fire
traverses the entire length of the internal boiler fluc, and on reaching the
back end, the current joins and mingles with that from the external furnace.
The combined current then turns back and divides into two portions, one
returning along two external flue passages formed between the lower part of
the external surface of the boiler shell, and the internal surface of the seating
brickwork. In this way the two currents pass to the front or furnace end of
the boiler, when they return again to the back or chimney end through two
higher external flues, and proceed thence to the chimney. These higher
external flues may beat such a level that the gaseous current passing through
them, may heat the steam in the steam portion of the boiler above the water,
and thus surcharge or superheat and dry the steam as fast as it is generated.
The external and internal furnaces are fixed alternately, so that the crude
unconsumed gaseous products from one fire are consumed and turned to
economical account by passing through the flame and more highly heated
current of the other. Instead of a single internal furnace and flue, the boiler
may be made with two parallel furnaces. These furnaces have their flues so
arranged that their gaseous currents combine in a combustion chamber at or
near the bridge. This combined current subsequently diverges into two
separate currents, which pass to the back end of the boiler, and then join,
traversing the flues in conjunction with the external furnace current,as herein-
beforedescribed. To insure regularity and certainty in the smoke consumption

page_text: or prevention, an automatic air supply valve is fitted up in the front or end
of the boiler, mounting and communicating with an air channel passing
to a hollow in the bridge, or to some other point at or near the bridge.
This air valve is connected with a steam pressure regulating apparatus,
such as that for which Mr. David Auld has already obtained British Letters
Patent, or modifications of such apparatus. When the steam pressure, as
indicated by such apparatus, falls, and it becomes necessary to fire, the
connection with the pressure apparatus causes the air valve to be opened,
so that as fresh coal is supplied, air is admitted to aid the combustion and
c.nsume the gaseous products.
A
By another arrangement, provision may be made for effecting the satis-
factory supply of the boiler with feed water in an economical manner.
float is fitted up inside the boiler, and as the water level falls, the descent
of this float is inade to admit steam from the boiler to work a pair of small
or "donkey" engines, which continue to pump water into the boiler until
the ascent of the float causes the actuating steam to be shut off.
And in order that our said Invention may be properly understood, wehave
hereunto appended, and shall now procee todescribe twoSheets of explanatory
Drawings, showing a mode of working out our said Invention in practice.
Figure 1, on Sheet 1 of the Drawings, is a vertical longitudinal sectionof a
steam boiler, as arranged according to our Invention; Figure 2 is a trans-
verse vertical section of the boiler as taken through the furnaces; Figure 3
is a front end elevation of a similar boiler; Figure 4 is half front end eleva-
tion and half transverse vertical section through the furnaces of a steam
boiler,showing a slightly modified arrangement of the external or lower grate
bars; Figure 5, on Sheet 2 of the Drawings, is a plan, partly in section, of a
set of three steam boilers combined,showing the donkeyfeed engines, and with
one of the boilers in horizontal section through its centre, the flues being
sectioned at different levels on each side. The boilers A, represented in the
Drawings, are of the cylindrical form with flat ends. Each boiler has two
internal furnaces B, which open at their back ends into a single combustion
chamber or space C, where the gases from the two furnaces are combined.
The combustion chamber C leads into two flues D, which convey the gases to
the back end of the boiler. Beneath each boiler is a large furnace E, provided
with two coaling doors F, and the gases from this furnace pass along a wide
flue &, running along under the boiler to the back end thereof. At the back
end of the boiler the gases from the external and internal furnaces are com-
mingled, one half of those from the lower external flue G mixing with those

page_text: from each of the internal flues D, and returning along a side flue H to the
front or furnace end of the boiler. At the front end of the boiler each side
flue H communicates with a flue I above it, along which the gases return to
the back end of the boiler, where the currents from the two flues I combine
and pass off at J. In this manner the gaseous currents from the several
furnaces are commingled, and as the furnaces are fired alternately; or in
rotation, the green smoke of one furnace mixes with the incandescent or highly
heated gases from the other furnace or furnaces, such smoke being thereby
consumed. To aid the consumption of the smoke, and to otherwise regulate
the action of the furnaces, provision is made for the supply of atmospheric air
at the bridges K of the lower external furnaces E. Passages L running
along the sides of the furnace through the brickwork convey the air from the
front of the boiler to a hollow space in the bridge K, and the air issues thence
into the furnace through apertures formed in the brickwork; the air is thus
heated by the radiation of heat through the sides of the furnace. The
admission of the air is regulated by valves Mat the front ends of the passages L,
these valves being worked by rods N passing up to levers on a small shaft O
running along over the front ends of the boilers, so as to be connected to the
entire set of air valves. This shaft O carries a short lever connected by a
rod P to a bell-crank lever Q, the other arm of which is connected to the
apparatus R. This apparatus R is Mr. Auld's patented apparatus, already
herein-before referred to, for regulating the fluedam persof steamboilers, andit
is so contrived in the present instance that when the float descends, and thereby
causes the damper to be opened, it also causes the air valves M to be opened
for the admission of air. Any self-acting apparatus for actuating the fluc
dampers of steam engines may in this manner be arranged to act on the air
supply valves likewise. In the present instance the boilers are represented as
set with the lowermost part of their internal furnace flues, on about a level
with the floor of the engine house. Access is obtained to the lower furnaces
E, and their ash-pits S, for the purpose of supplying the fuel to these furnaces
by a recess or pit T, and this pit or recess is covered with a stageing U of
wood or iron for supplying the upper internal furnaces B from. Of course if
the bottoms of the ash-pits S or of the lower furnaces E coincide with the floor
level of the engine house, the stageing U for firing the upper furnaces B will
require to be elevated above that level. In Figure 1 the grate bars V of the
lower external furnace E are represented as placed upon straight transverse
supporting bars W, thus forming a flat grate surface; but in Figure 4 the
supporting bars W are curved so as to give the grate surface a curved form,

page_text: and make it equally or nearly equally distant from the boiler surface at all
parts. It will be obvious to the practical engineer, that instead of firing both
the internal and external furnaces at one end of the boiler, the external furnace
may be fired at one end, and the internal one at the other.
In the arrangement of' boilers represented in the Drawings, and as more
particularly shown in the plan Figure 5, Sheet 2, the furnace gases do not
after leaving the boilers A pass at once to the chimney X, but are first made
to envelope or pass round a vessel Y, into which the feed water is passed
before being taken into the boiler. In this manner a portion of the heat which
would otherwise pass up the chimney is turned to useful account in raising the
temperature of the feed water. The feed water is pumped into the boilers
according to another portion of our Invention, by means of a pair of small or
donkey engines, which may be conveniently placed upon the top of the boiler
brickwork, as shown in plan at Z, in Figure 5, Sheet 2. The donkey engines
are composed in the present instance of two small steam cylinders a working
two plunger pumps / direct.
b
The pistons of the cylinders also turn a small
crank shaft with a fly wheel c upon it, which shaft carries eccentrics for
working the valves, and has the crank of one cylinder at right angles to the
crank of the other cylinder, so that the engines can be started or stopped in
any position. The steam for working these engines is supplied from one of
the boilers by the pipe d, the supply being regulated by the valve at e, shewn
in section in Figure 1. This valve e is of the equilibrium kind, and is worked
by a lever f, connected by a rod g, passing through a stuffing box in the boiler
casing to the water level float h. These details are so arranged that when the
water level sinks too low, the float & pulls down the lever f, and opens the
valve e. This allows steam to pass into the pipe d, and thence into the donkey
engines, which are thus set to work, and pump water into the boilers until the
level rises, and carrying up the float / causes the valve e to close. The water
is drawn from the feed heating vessel Y by the pipe i, which communicates
with the suction valves of both pumps b, and from the pumps pases into the
pipe j, communicating on one side by a weighted valve & with a pipe returning
to the vessel Y, and on the other side with an air vessel 7, and branch m
leading down to the horizontal pipe n in front of the boilers. This pipe n
communicates with each of the boilers by branches o,fitted with stop-cocks, by
means of which the communication with any one of the boilers may be cut off
at pleasure. A clack valve is placed on the pipe m atp, to prevent the water
from returning along this pipe. The object of combining two steam cylinders
n the donkey feed engines, is to have them so that they can be started at any

page_text: point of their stroke or revolution, and any kind of steam engine, such as
a rotatory engine for example, which can be started at any point of its stroke
or revolution, may be used for pumping the feed water into the boilers:
Having now described and particularly ascertained the nature of our said
Invention, and the manner in which the same is or may be used or carried
into effect, we may observe, in conclusion, that we do not confine or restrict
ourselves to the precise details or arrangements which we have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of our Invention; but what
we consider to be novel and original, and therefore claim as the Invention
secured to us by the herein-before in part recited Letters Patent, is,-
First, the general arrangement and construction of steam boilers and
furnaces, and apparatus connected therewith, for the obtainment of superior
concentration of boiler or steam power, the economy of fuel, and the prevention
of smoke, as herein-before described.
Second, the application and use in or upon steam boilers of external and
internal furnaces or fire-places, working in combination, for the purposes
herein-before described.
Third, the system or mode of working steam boilers, wherein the heated
currents from combined external and internal furnaces or fire-places fired
alternately are commingled in the flues of the boilers.
Fourth, the system or mode of firing the internal furnaces of steam
boilers, having external and internal furnaces combined, by the agency of a
permanent or fixed stage or platform, erected over the stoke hole of the
lower or external furnace.
Fifth, the system or mode of arranging and working steam boilers, wherein
the external furnace or furnaces are fired at one end of the boiler, and the
internal furnace or furnaces at the other.
Sixth, the system or mode of super-heating or surcharging steam in boilers
with the external and internal furnaces combined, by carrying the external
flue or flues above the water level of the boilers.
Seventh, the application and use in or upon steam boilers wherein external
and internal furnaces or fire-place are combined to work in concert of two or
more separate furnaces either external or internal.
Eighth, the system or mode of insuring regularity and certainty in the
prevention or consumption of smoke by the use of an air valve in connection
with a steam pressure regulating apparatus worked from the boiler.
Ninth, the system or mode of supplying steam boilers with water by means

page_text: of an internal boiler float connected with the stop valve of a small steam
engine forming the actuating power of the feed water pump, and consisting
of two reciprocating cylinders or a single rotatory engine, arranged so as to
be capable of starting at any point of the stroke.
In witness whereof, we, the said David Auld and John Stephen, have
hereunto set our hands and seals, this Eighteenth day of August,
One thousand eight hundred and fifty-six.
DAVID AULD. (1.6.)
JOHN STEPHEN. (L.S.)