IMPROVE- MENTS IN FURNACE FIRE-BARS
Year: 1877

page_text: LETTERS PATENT to Robert Robson Newlove and George Marshall, both of the
Town and County of Nottingham, Engineers, for the Invention of "IMPROVE-
MENTS IN FURNACE FIRE-BARS."
Sealed the 21st December 1877, and dated the 9th July 1877.
PROVISIONAL SPECIFICATION left by the said Robert Robson Newlove and
George Marshall at the Office of the Commissioners of Patents on the 9th July
1877.
ROBERT ROBSON NEWLOVE and GEORGE MARSHALL, both of the Town and
County of Nottingham, Engineers. "IMPROVEMENTS IN FURNACE FIRE-BARS."
The object of this is so to construct fire-bars as to increase the air supply to
furnaces, and thereby produce better combustion of fuel, at the same time to make
the bars stronger without materially adding to their weight, whereby they last
much longer than heretofore, all as hereafter described.
According to one arrangement we form fire-bars with teeth-like projections on
both sides (excepting side bars, which have teeth-like projections on one side only),
and these teeth are connected with each other by a cross bar or web, thus adding
material strength to the bar. The bars are so arranged in the furnace that the
teeth-like projections on one bar take into the undulating space of the adjacent bar.
These bars are suitable for tubular and brick furnaces.
According to another arrangement the bars are formed on both sides with slots
or spaces, and formed in the middle with the teeth-like projections connected with the
cross bar or web as before, the teeth-like projections taking into one another. In
this case the bars are formed with two main webs, one on each side, at the side of
which there are slots or spaces for the purpose of "pricking." These bars are
suitable for marine and locomotive purposes. The cross bars or webs connecting
the teeth-like projections to each other we can make either straight, curved, and
with a slot or slots, if desired.*

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Robson Newlove and George Marshall in the Great Seal Patent
Office on the 9th January 1878.
ROBERT ROBSON NEWLOVE and GEORGE MARSHALL, both of the Town and
County of Nottingham, Engineers. "IMPROVEMENTS IN FURNACE FIRE-BARS."
The object of this Invention is so to construct fire-bars as to supply the air
required for the combustion in a more perfect manner by the more even and free
supply and distribution of same; also to increase the strength and durability of
the bar without- adding materially to the weight of same. For this purpose we
construct the bar with teeth-like or undulating sides or parts in such a manner as
to produce teeth-like, tongued, or undulating spaces through the grate for the
admission of air therethrough.
We also, where required, strengthen the bar by connecting the teeth with each
other by a web.
In some cases, for broad furnace bars, we cast the same with slots or perforations
for additional air supply.
And in order that this Invention may be more fully understood we will now
proceed to describe the same with reference to the accompanying Drawings, whereon
are shewn some typical forms of fire-bars according to this our Invention.
Figure 1 is a side view of a portion of a fire-bar; and Figure 2, an end view of
same.
Figure 3 is plan of a portion of two adjoining fire-bars, the upper one being a
side bar or one fitting against the inner side of the furnace, and the lower one being
one of the other bars, the former having therefore teeth-like projections on one side.
only, and the latter on both.
Figure 4 is a cross section through both bars on the line A, B.
a, a, are pieces passing across from one tooth c to another, and forming a longitu-
dinal web on each side of the ordinary centre web b (or side web b in the case of
the side bar aforesaid), see Figures 6 and 7. The teeth-like or undulating sides of
two adjoining bars so fit into one another as to leave an undulating air space e.
between. d, d, are slots or spaces cast through the bars; it will thus be seen that
because of the undulating air spaces and the slots a large surface of the bar is
exposed to the cooling influence of the air, whereby excessive heat and burning
away and clinkering of the bar is prevented; the air supply is well distributed,
whereby a complete, that is, economical combustion is ensured, the metal in the bai
being at the same time so distributed that the bar is of great strength, and resists
sagging and warping. The slots d also serve the purpose of "pricking" the fire.
This form of bar is suitable for boilers with metallic or with brick-built furnaces.
Figure 5 is plan of a portion of a fire-bar with teeth-like or undulating sides of a
slightly different form, the projections and hollows on both sides being respectively
opposite each other, whereas in the first-described bar the projections on one side of
a bar are opposite the hollows on the other side of the same bar. This bar is made
with a central longitudinal web.
Figure 6 is plan of a portion of, and Figure 7 cross section through a fire-bar, in
which the undulating air space e is formed through the middle of the bar itself;
instead of being between two adjacent bars, as previously described. There is a
longitudinal web b on each side.
For furnaces intended to burn rubbish we prefer to employ furnace bars so formed
or combined that a great portion of the air required for combustion may be conveyed
through the bars themselves to the space behind the bridge, where it then arrives in
a warm or hot state; we in that case ensure the free access of air to the front ends
of the fire-bars, and the air supply to the ash-pit space below the grate may be
proportionately diminished and regulated as required.
Figure 8 is a side elevation of a portion of the outer side of a bar constructed
suitably for the above purpose, and in this case made in two halves; Figure 9 is a

page_text: plan of a portion of the two adjoining half bars; Figure 10, a side view of a portion
of the inner side of one; and Figure 11, a cross section through the two half bars.
The sides are in this case made undulating, or with projections and hollows, as in
the previous Figures, and the bar is more particularly similar to the one shewn at
Figure 5, the main difference being that this one is made in two halves, the division
passing through the centre web, which is made hollow, forming an air passage
through the bar. d, d, are air spaces, which may be formed through the bar to
admit air, additional to the space over the grate, and to facilitate " pricking." The
bars are in this case put so close together as to make the undulating intermediate
spaces every narrow.
Figure 12 is a side view, Figure 13 plan, and Figure 14 cross section illustrating
another form of undulating hollow bar, made in two halves, for forming an air flue
to supply air to the space behind the bridge; this air space or flue is in this case of
an increased length, because of the deviations from the straight direction, and we
thereby gain the advantage that the air will become more heated in its passage
therethrough, and thus produce a more perfect combustion of the gaseous fuel behind
the bridge. The undulating air spaces e are also in this case comparatively narrow
when the bars are intended for burning rubbish.
Figure 15 is a longitudinal section; and Figure 16, a cross section of a boiler
fitted with the aforesaid hollow bars. e is a plate for almost closing the ash-pit; it
may be fitted with sliding or other plate at e¹ for regulating the air supply through
same to the under side of the grate. The bars are open in front, and terminate at
the back into the space behind the bridge, thus conveying air through the bars to
the said space, or with an open hollow or split bridge the air would be conveyed
into the bridge.
When it is desired to fit the fire-bars with appliances for rocking them in order
to prevent the formation of clinkers we propose to arrange such appliances as shown at
Figures 17, 18, and 19, Figure 17 being a front view, Figure 18 a plan, and Figure 19
a side view of a set of bars made as aforesaid, fixed transversely in the furnace, and
arranged with rocking appliances. Every alternate fire-bar has fixed to its front
end a small bracket f; all the brackets fare jointed to a bar g, which by means of
a rod h is connected to a short lever j on a stud or spindle k, formed with a squaro
end, and working in a bracket fixed under the dead plate m.
A lever or spanner
placed on the square end of affords facility for rocking every fire-bar or every
alternate fire-bar, thus breaking up the fuel which has begun to cake on the grate,
and clearing the air spaces for the free admission of air.
And having thus described and ascertained the nature of this Invention we declare
that we claim, the construction of fire-bars with undulating sides or parts forming
undulating spaces for air supply, all substantially as set forth.
In witness whereof, we, the said Robert Robson Newlove and George Marshall,
have hereunto set our hands and seals, this Seventh day of January, in the
year of our Lord One thousand eight hundred and seventy-eight.