IMPROVEMENTS IN AND CONNECTED WITH THE FURNACES OF STEAM BOILERS AND EVAPORATORS, AND IN PREVENTING OR REMOVING INCRUSTATIONS IN STEAM BOILERS."
Year: 1878

page_text: LETTERS PATENT to George Sinclair, of Leith, in the County of Mid Lothian,
North Britain, for the Invention of "IMPROVEMENTS IN AND CONNECTED WITH
THE FURNACES OF STEAM BOILERS AND EVAPORATORS, AND IN PREVENTING
OR REMOVING INCRUSTATIONS IN STEAM BOILERS."
PROVISIONAL SPECIFICATION left by the said George Sinclair at the Office
of the Commissioners of Patents on the 8th April 1878.
GEORGE SINCLAIR, of Leith, in the County of Mid Lothian, North Britain.
"IMPROVEMENTS IN AND CONNECTED WITH THE FURNACES OF STEAM BOILERS
AND EVAPORATORS, AND IN PREVENTING OR REMOVING INCRUSTATIONS IN STEAM
BOILERS."
This Invention comprises improvements which are in part modifications or
developments of those described in the Specification of Letters Patent granted to
the present applicant, and dated 23 May 1877 (No. 2004).
One of the present improvements relates to such steam boilers or evaporators as
are heated by external fires in brick furnaces, and consists in placing one or more
water tubes along each side and across the inner ends, to prevent the adherence of
clinkers to the brickwork, and consequent interference with the movable fire-bars
or stoking apparatus.
In the case of a steam boiler these furnace tubes may be connected to the boiler,
but in the case of an evaporating pan they must be connected to a separate cisteru,
so that the water in them may change by circulation.
In the case of internally fired boilers with moving fire-bars, one, two, or more
round water tubes are placed just beneath and beyond the inner ends of the fire-
bars to cool them, and prevent the rapid destruction which commonly takes place
with mechanical stoking apparatus. When more than one tube are applied in this
way, they are by preference placed close together.

page_text: Instead of a number of round tubes a single oval or flat tube or box may be used,
but its under side is made concave to admit of the end flanges being conveniently
rivetted to the sides of the boiler flue.
The furnace bars are by preference made as described in the earlier Specification
berein-before referred to, but blocks fitted to the cranks are fixed in the connecting
rod ends, and to lugs fixed in connection with these blocks rods are jointed for
working the pusher box or plate at the bottom of the coal hopper. The rods are
connected to the pusher box by being entered through holes, in which they are
quite loose, and having nuts or keys fixed on their inner ends, and which pull out
the box, whilst the inward movement depends on a tube on the rod, such tube being
adjusted by a screw nut working on a screwed part of the rod.
A hinged flap or short door is fitted at the top of the inner opening of the hopper,
and has a weight applied to regulate its closing tendency, so that it may keep back
small coal above its bottom edge, but yield temporarily to any large lump.
The dumb plate which forms the bottom of the hopper has teeth or projections
formed on its under side six or eight inches from its inner edge, and air has access
between these teeth into the furnace. The bearer for the front ends of the fire-bars
is carried in hanging brackets cast on or fixed to the under side of the dumb plate
at each side of the furnace, and screws are fitted to these brackets to raise or lower
the fire-bar bearer, so as to let in more or less air undor the dumb plate.
A cleaning door is provided in one of the side brackets to allow of the space
between the dumb plato and the front ends of the fire-bars being cleared out when
necessary.
In order to prevent the formation of incrustations in steam boilers, or to remove
them when formed, there is by this Invention, according to one modification, intro-
duced into each boiler a quantity of the alkaline tar or soda water produced as a
waste in mineral oil works; or, by another modification, crude paraffin or shale oil
is mixed with the waste alkaline lye of the papermaker, or the two may be boiled
together. The quantities to be used will depend on the size of the boiler, quality
of the feed water, and. other circumstances; but, for a moderately sized boiler and
bad water about one gallon of either of the two liquors may be used per day.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Sinclair in the Great Seal Patent Office on the 4th October
1878.
GEORGE SINCLAIR, of Leith, in the County of Mid Lothian, North Britain.
"IMPROVEMENTS IN AND CONNECTED WITH THE FURNACES OF STEAM BOILERS
AND EVAPORATORS, AND IN PREVENTING OR REMOVING INCRUSTATIONS IN STEAM
BOILERS."
My said Invention comprises improvements which are in part modifications or
developments of those described in the Specification of Letters Patent granted to
me, and dated 23 May 1877 (No. 2004).
My presont improvements will be most readily understood with the aid of ox-
planatory Drawings, of which I hereunto append five Sheets, to be herein-after
referred to, and representing various modifications of furnaces for steam boilers, it
being understood that my improvements are also applicable to open or other
evaporating boilers or vessels. In these Drawings the same reference numerals are
used to mark the same or like parts wherever they are repeated.
Figures 1 and 2 on Sheet 1 of the accompanying Drawings are vertical sections
as at right angles to each other of a steam boiler 1, heated by an external fire in a
furnace constructed in brickwork 2.
One of my present improvements consists in placing a water tube 3 (or it may
be more than one) along each side of the furnace, to prevent the adherence of
clinkers to the brickwork, and consequent interference with the movable fire-bars 4
or stoking apparatus. When the fire-bars 4 extend back to or nearly to the bridge 5,
I also place a similar water tube across the front of the bridge.
In the case of a steam boiler these furnace tubes may be connected to the boiler
by pipes, such as are indicated partly by dotted lines at 6, 7, in the Figures, there
being two such connecting pipes in the case of each tube, so that the water may
circulate through the tubes; but in the case of an evaporating pan they must
be connected to a separate cistern, so that the water in them may change by
circulation.
Figure 3 on Sheet 2 of the accompanying Drawings is a longitudinal vertical
section of an externally fired boiler, of which the licating surface consists inainly of
inclined tubes 8, having the water inside of them, and shows the application to the
furnace of such boilers of the lateral water tubes 3, herein-before described, and
also of other improvements comprised in my present Invention.
In the case of externally fired boilers 9, such as are shown in longitudinal
vertical section in Figures 4 and 5 on Sheet 3 of the accompanying Drawings, one,
two, or more round water tubes 10 (Figure 5) are placed just beneath and beyond
the inner ends of the movable fire-bars 4, to keep them comparatively cool, and
prevent the rapid destruction which commonly takes place with mechanical stoking
apparatus. When more than one tube 10 are applied in this way, they are by
preference placed very near or close together.
Instead of a number of round tubes (10) a single oval or flat tube or box 11
(Figure 4) may be used, its under side being by preference made concave, to admit
of the end flanges being conveniently rivetted to the sides of the flue.
The furnace bars 4 are by preference made as described in my earlier Specification,
hercin-before referred to, but I construct or arrange the parts in connection with
them in an improved manner, which is most fully shown on Sheets 4 and 5 of the
accompanying Drawings, Figure 0 being a front elevation, and Figure 7 a longi-
tudinal vertical section, showing a boiler 9 having two internal furnaces fitted with
my improved stoking apparatus. The bars 4 are made to reciprocate in separate
pairs by cranks 12 on a revolving shaft, to which cranks they are connected by
rods 13 formed with forked ends. In these forked ends there are fixed blocks 14,
which fit on the cranks 12, and are formed with or have fixed to them lugs 15

page_text: projecting upwards, and to these lugs 15 are jointed rods 10 for working the pusher
box or plate 17 at the bottom of the coal hopper 18. The rods 16 are connected to
the pusher box 17 by being entered through holes, in which they are quite loose,
and having nuts or keys fixed on their inner ends, and which pull out the box,
whilst the inward movement depends on a tube 19 on the rod 16, such tube 19
being adjusted by means of a screw nut working on a screwed part of the
rod 16.
A hinged flap or short door 20 is fitted at the top of the inner opening of the
hopper 18, and has a weight applied to regulate its closing tendency, so that it may
keep back small coal above its bottom edge, but yield temporarily to any large
lump.
The dumb plate 21, which is at the bottom of the hopper 18, has teeth or pro-
jections 22 formed on its under side six or eight inches from its inner edge, and air
has access between these teeth into the furnace. The bearer 23 of the front ends of
the fire-bars 4 is carried in hanging brackets 24 cast on or fixed to the under sido
off the dumb plate 21 at each side of the furnace, and screws 25 are fitted to these
brackets to raise or lower the fire-bar bearer 23, so as to let in more or less air
under the dumb plate 21.
A cleaning door may be provided in one of the side brackets 24 to allow of the
space between the dumb plate 21 and the front ends of the fire-bars 4 being cleared
out when necessary.
When English or other coal which is liable to cake is to be used in the furnace,
I construct a short fire-brick arch 26, as shown in Figures 4 and 5, between the
hopper 18 and the front of the boiler, and the inside of this arch becoming highly
heated insures the ready ignition of the coal and diminishes the caking action.
I also in some cases fix two or more pieces of curved or angled iron 27, Figure 5,
to the inner edge of the dumb plate 21, such piccos 27 serving to break up and
divide the coal as the latter is being pushed inwards, and to admit the air from under
the dumb plate up more freely amongst the coal.
The pieces 27 inay be perforated for the air to pass through; I form the inner
edge part 28 of the dumb plate 21 of a narrow malleable iron plate attached to the
main part, which edge part 28 can be easily renewed when burnt away or injured
by the action of the fire.
In some cases, as for example, whero caking coal is to be used, I make the fire-
bars 4 with inclined edges 29 at the parts resting on the bearers 23 and 30, which
makes the bars rise and fall as they reciprocate longitudinally; and as the bars
moving inwards will rise whilst those moving outwards fall, the coal on them will
be thereby broken up.
In Figure 3 I show an arrangement which may be advantageously adopted in
many cases, and in which there is placed beyond the inner ends of the main movable
fire-bars 4, and at a lower level, a set of transverse fire-bars 31, which receive the
partly consumed coal from the main bars 4. Air is admitted beneath the transverse
bars 31 through holes in a plate 32 fixed beneath the transverse water tube 11;
and side doors 33, 34, are provided for removing clinkers from above the bars 31,
or ashes from beneath them.
Where the supplementary transverse fire-bars 31 are not used, and generally in
the case of internal furnaces, I employ a plate 35 for closing the space beneath the
water tube 11, this plate 35 being made movable to admit of the withdrawal of
ashes which fall over the inner ends of the fire-bars 4.
In order to prevent the formation of incrustations in steam boilers, or to remove
them when formed, I, according to one modification, introduce into each boiler a
quantity of the alkaline tar or soda water produced as a waste in mineral oil works.
Or by another modification I take paraflin oil, or shale oil, or petroleum, preferring
the qualities of such oils which are of a specific gravity of at least 880, water being
1000, and mix the samo with the waste alkaline lye of the papermaker. In some
cases this lye requires to be boiled with lime to render it sufficiently caustic; and
when it is not conveniently obtainable any caustic soda liquor may be substituted

page_text: for it. The quantities of the alkaline tar, or of the soda water, or of the com-
pound of oil and lye to be used will depend on the size of the boiler, quality of the
feed water, and other circumstances; but for a moderately sized boiler, say of 40 H. P.,
about one gallon of any of them, or of a mixture of one or more of them may be
used per day.
Having thus particularly described my said Invention, and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise details
lierein described or delinoated, but that what I believe to be novel and original,
and claim as the Invention secured to me by and in terms of the herein-before in
part recited Letters Patent is,-
1. The placing of water tubes (3) along the sides of the furnace when the
slides are of brickwork, substantially as and for the purpose herein-before
described.
2. The placing of two or more small water tubes (10), or a single large water
tube or box (11) transversely beneath the inner ends of the movable firo-bars (4),
such tubes or box being in communication with the boiler or with a separate
cistern, and arranged in the improved manner herein-before described.
3. The construction or arrangement of the parts by which the pushing box (17)
is worked in connection with the connecting rods (13) and cranks (12), substantially
as herein-before described.
4. The construction and arrangement of the dumb plate (21), and parts for sup-
porting and adjusting the front ends of the fire-bars (4), and the air inlets between
them and the dumb plate, substantially as herein-before described.
5. The fixing of upwardly projecting pieces (27) at the inner edge of the dumb
plate (21), substantially as and for the purposes herein-before described.
6. The using of soda, tar, or soda water, for preventing or removing incrusta-
tions in steam boilers, as herein-before described.
7. The using of a mixture of mineral oil with papermakers' waste or other
alkaline lye for preventing or removing incrustations in steam boilers, as herein-
before described.
In witness whereof, I, the said George Sinclair, have hereunto set my hand
and seal, this First day of October, in the year of our Lord One thousand
eight hundred and seventy-eight.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
GEORGE SINCLAIR. (L.S.)