IMPROVEMENTS IN THE FURNACES OF STEAM BOILERS
Year: 1879

page_text: LETTERS PATENT to John Whitworth Lord, of Bow, in the County of Middlesex,
Engineer, for the Invention of "IMPROVEMENTS IN THE FURNACES OF STEAM
BOILERS."
Sealed the 2nd March 1880, and dated the 4th September 1879.
PROVISIONAL SPECIFICATION left by the said John Whitworth Lord at the
Office of the Commissioners of Patents on the 4th September 1879.
JOHN WHITWORTH LORD, of Bow, in the County of Middlesex, Engineer.
PROVEMENTS IN THE FURNACES OF STEAM BOILERS.'
"IM-
This Invention relates to improvements in the furnaces of steam boilers, and
consists in a means for the better distribution over against the heating surface of
the boiler of the flame and heated products of combustion, as and after passing out
of the furnace or fire box.
According to my Invention the flame and heated products of combustion are not
allowed to pass in a body over the bridge, and as is usual take one direction
coming in contact with only a portion, frequently small, of the heating surface of
the boiler. These flame and heated products of combustion are arrested directly
by a plate of fire clay, fire brick, or other suitable material perforated with holes
suitable in size and number to the capacity of the boiler, and are thus compelled to
distribute and pass through equally over the whole surface of such plate. This
plate is also frequently backed at a short distance from it by a dead plate of
similar material to again deflect the flames and products of combustion in the
direction necessary to cause them to come well in contact with the whole of the
heating surface of the boiler. Air may also be admitted behind the bridge when
required, the admission thereof being governed by a valve operated from the front
of the boiler. In applying my Invention to an ordinary horizontal tubular boiler
with internal firing flue, the above described perforated plate, I prefer to fill up the
space above the bridge of the boiler. Behind this and between it and the tube
plate is the dead plate depending from the top, and thus deflecting the flame from
the furnace downwards and causing it to pass underneath it, and on reaching the
other side the flame and gases spread over the whole surface of the tube plate, and
80 pass as nearly equally as possible through the whole of the tubes. Slight
modifications only are necessary in applying this Invention to other forms of
boilers, and will immediately present themselves to the practical boiler maker, the

page_text: principle of the Invention being as before stated to prevent the flame and heated
products passing through the boiler in in a body, and to well distribute them over
the heating surface. In the case of an ordinary iron tubular boiler the distribution
will be comparatively equally effective in causing the flame to be well distributed
over, and to impinge on the whole of the heating surface. Single or double tube
boilers may be fired underneath on this principle, and the ordinary firing tube or
tubes be converted into return flues in a manner which is well known. Another
part of my Invention consists in dividing the fire longitudinally by a wall of fire
clay, fire bricks, or other suitable material, such wall being perforated so as to
afford communication between the two fires, and when there is sufficient room I
prefer to make this wall double the internal space communicating with the outside
atmosphere by perforations in the front end of the boiler. The effect of this wall
is as follows:-In practice one fire only should be coaled at a time, thus leaving
the other at that time red. The red fire being hottest, and causing the quicker
draft draws the smoke from the black fire through the perforations of the inter-
vening plate onto the red fire, and the smoke is thus effectually consumed.
also passes into the internal space in the wall at the front through the perforations
and reaches the fuel in combustion in a highly heated state, thus effecting great
economy.
Air

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Whitworth Lord in the Great Seal Patent Office on the 4th
March 1880.
JOHN WHITWORTH LORD, of Bow, in the County of Middlesex, Engineer. "Iм-
PROVEMENTS IN THE FURNACES OF STEAM BOILERS."
This Invention relates to improvements in the furnaces of steam boilers.
According to my Invention I effect a better distribution of the flame and heated
products of combustion over and against the heating surface of the boiler. I also
effect more nearly perfect combustion, and prevent the formation or escape of
smoke.
And in order that my Invention may be fully understood and readily carried
into effect, I will proceed to describe it with the aid of the accompanying Drawings,
reference being had to the letters and Figures marked thereon, and in which
Figs. 1 and 2 illustrate an internally fired tubular boiler with my improvements
as adapted to that class of boiler attached, Fig. 1, being a front elevation with one
furnace door reinoved, and Fig. 2 a longitudinal sectional elevation at a, b, Fig. 1.
The flame and heated products of combustion rising from the burning fuel on
furnace bars A are not allowed to pass in a body over the bridge, but are arrested
by a plate B, filling up the space between the bridge and the boiler. This plate is
perforated with holes, round or other shaped, of such size and number as will not
check the draught too much, but will cause such products of combustion to seek all
the holes for escape, and so distribute themselves and pass through equally (or
nearly so) over the whole surface of the plate. More than one such plate may be
used if desired, one behind the other. Behind this perforated plate B is a dead
plate C depending from top of the fire tube D of the boiler, and filling up the
whole sectional area of the tube with the exception of only sufficient space at the
bottom to allow the products of combustion to pass freely underneath, which they
are thus forced to do, and immediately they reach the other side they rise and
spread over the whole surface of the tube plate E, and pass equally (or nearly so)
through the whole of the tubes F. More than one such dead plate C may be used
if desired, but I 'find only one preferable. Or instead of the aperture being left
only at the bottom of the dead plate C, there may be smaller apertures at intervals
around its periphery, the object in either case being to equalise the passage of
the products of combustion through the whole of the tubes F after traversing,
which they are led away as desired.
Another part of my Invention consists in dividing the fire into two by a longi-
tudinal wall G made of fire clay, fire brick, or other suitable material. This wall
has apertures H passing horizontally through it, and allowing of communication
between the two fires and channels I, putting such apertures in communication
with the outer atmosphere. As shown in the Drawings these channels I are
vertical, and communicate with the atmosphere in the ash pit. There may how-
ever be communication with the outer air through the end of the wall at the front
or back of the boiler. This wall allows of the passage of fresh hot air to the
upper side of the fuel in combustion, and without having lost its oxygen by
passing through the fuel. "This effects brilliant combustion, and prevents almost
entirely the formation or escape of smoke. In furnaces so constructed one fire only
should be coaled at a time. The other fire then being hottest and having a quicker
draught has a tendency to draw the more sluggish products of combustion
including any smoke that may be formed from the black fire through the apertures
in the intermediate wall in traversing which aperturs they are met and com-
mingle with the blast of hot fresh air rising up the channels I, and together they
pass into the hot fire on the other side of the wall, where any smoke which may
have entered is effectually consumed. In practise I find that this wall is made very
effective and durable by being constructed of moulded blocks of fire clay, the

page_text: apertures and channels being formed in the moulding. Two of these blocks are
illustrated at Figs. 8 & 9, of the accompanying Drawings. A convenient size for
the apertures H is, say, 21, inches long, by 2 inches deep with vertical channels I,
say, 1 inch by 2½ inches sectional area. As will be seen the blocks are
moulded to fit one into the other, and with them the wall may be readily and
effectively constructed. Air may be admitted near the bridge if desired, either in
front or behind, such admissions being governed by a suitable valve as is well
known. In the wall J at back of ash pit a door is provided to enable any deposit
at the back of the bridge to be readily cleared.
Figs. 3 & 4, show the perforated plate B and dead plate C applied to an ordinary
Cornish boiler fired underneath, Fig. 3 being a transverse sectional elevation at c, d,
Fig. 4, and Fig. 4 a longitudinal sectional elevation at e, f, Fig. 3.
Figs. 5, 6, & 7 show my improvements attached to an ordinary egg ended
boiler Fig. 5 being a transverse sectional elevation at g, h, Fig. 6, Fig. 6 a longi-
tudinal sectional elevation at i, j, Fig. 5, and Fig. 7 a sectional plan at k, l, Fig. 5.
In addition to the improvements already described viz., perforated wall B, dead
plate C, and division wall G, all of which are shown here applied, there are also
shown other improvements. Apertures K are formed in the side setting at
intervals along the length of the furnace communicating vertically or nearly so
with a horizontal flue L running in the direction of the length of the boiler, and
turning downwards between perforated plate B, and dead plate C. Up each of
these apertures K a part of the flame and heated products are caused to pass by
the draught, and all are carried along flue L to the back of perforated plate B
where they commingle with what has passed through plate B, and together all
descend under plate C, and on reaching the other side thereof rise and well impinge
against the boiler shell, and are thence led away as desired by flues in the ordinary
.manner. In combination with apertures K the furnace bars may be set a short
distance (say half an inch) from the side of the furnace to allow of the ascent of
fresh hot air.
These apertures K in the side setting of the boiler, and the longitudinal flues L
may be applied to the form of boiler shown at Figs. 3 & 4, in addition to the
other improvements described. The dividing wall G may be omitted in small
furnaces, or in other cases when desired.
I do not confine myself to the exact detail hereinbefore described and illustrated,
as the same may be modified without departing from the principles of my said
Invention.
I claim as my Invention, to be secured by the herein before in part recited Letters
Patent,
1. The combination with one or more plates B of one or more plates C, sub-
stantially as liereinbefore set forth and described and illustrated in the accom-
panying Drawings.
2. Partition wall G, substantially as hereinbeforo set forth and described and
illustrated in the accompanying Drawings.
3. The combination of side apertures K with one or more communicating flues L,
also the same in combination with dead plate C, all substantially as herein before
set forth and described and illustrated in the accompanying Drawings.
In witness whereof, I, the said John Whitworth Lord, have hereunto set
my hand and seal, this Second day of March, in the year of our Lord
One thousand eight hundred and eighty.
JOHN W. LORD. (L.S.)