Certain Improvements in Fire Bars for Steam Boiler and other Furnaces.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Certain Improvements in Fire Bars for Steam Boiler and other
Furnaces.
I, EDWARD PROSSER DAVIS, of 17, Lenton Road, The Park, Nottingham, in
the County of Nottingham, Iron Master, do hereby declare the nature of this
invention to be as follows:-
This invention consists of the hereindescribe improvements in fire bars for
steam boiler and other furnaces. My improved fire bars are of that kind which.
are constructed to convey heated air from the ash pit and front part of the furnace
to the back of the bridge to ignite the furnace gases and complete the combustion
and thus prevent smoke and econ mise fuel. Fire bars of this kind have usually
been made of an enclosed hollow or tubular section and have therefore been more
expensive to cast than are the ordinary solid fire bars.
According to this invention I make the fire bars of such a section that when two.
of my fire bars are placed side by side in the furnace they together form a chamber
along which the air will pass from the ash pit and from the front part of the
furnace and be heated and discharged behind the bridge where the heated air will
mix with the partly burnt gases and complete the combustion. My improved fire
bars can thus be cast as cheaply as can ordinary solid fire bars.
My improved fire bars may for instance be made of the same section as an
ordinary fire bar but with a projecting rib running along the top at one or both
sides, and below the said rib there are at one or both sides of the bar inverted
V-shaped or other inclined projections or ribs the lower edges of which are at short
distances apart, so that when the bars are placed together in the furnace the small
spaces between the lower edges of the V-shaped or inclined projections will form
openings to admit air from the ash pit to the chamber or enclosed space between
the two bars which air is by the inclined surfaces of the projections directed
against the hottest parts of the bars so as to be thoroughly heated on its passage
to the back of the bridge. Any small ashes falling through the bars into the air
chambers cannot lodge there as such ashes will fall down the inclined surfaces and
through the said bottom openings into the ash pit.
In addition to the said inverted V-shaped or inclined projections, the bars may
be made with openings to admit air into the enclosed spaces between them. The
upper parts of the bars may if desired have small spaces through which part of
the heated air from the chamber between the bars can pass up through the burning
fuel.
The cross bearer which carries the ends of the two sets of fire bars (when two
sets are used) is adapted to receive the ends of the bars and may if desired be
made with cross openings for the heated air to pass through from the front set of
the bars to the back set; or the said cross bearer may be made solid and the bars
arranged to rest upon the top of it and to abut together or engage one within the
other.
The said longitudinal ribs and the V-shaped or inclined projections of the bars
may if preferred be made to engage with corresponding ribs or recesses formed in

page_text: the ribs or V-shaped or other inclined projections on the next bars so as to more
effectually enclose the air in the passages between the bars and ensure proper
currents of heated air therethrough.
Dated this 15th dox of lune 1906
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Certain Improvements in Fire Bars for Steam Boiler and other
Furnaces.
I, EDWARD PROSSER DAVIS, of 17, Lenton Road, The Park, Nottingham, in
the County of Nottingham, Iron Master, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention consists of the hereindescribed improvements in fire bars for
steam boiler and other furnaces. My improved fire bars are of that kind which
are constructed to convey heated air from the ash pit and front part of the furnace
to the back of the bridge to ignite the furnace gases and complete the combustion
and thus prevent smoke and economise fuel. Fire oars of this kin I have usually
been made of an enclosed hollow or tubular section and have therefore been more
expensive to cast than are the ordinary solid fire bars.
According to this invention I make the fire bars of such a shape that when
placed together side by side in the furnace they form air chambers in the upper
part of the bars in which the air is heated and through which the air will pass
from the ashpit and from the front part of the furnace and be discharged behind
the bridge where the heated air will mix with the partly burnt gases and complete
the combustion. The said air chambers are made with air inlets or openings
into the ashpit so constructed with inclined surfaces that any ashes or dust finding
its way into the air chambers between the bars will fall down the inclined surfaces
into the ashpit through the said air inlet openings.
The advantages which are obtained by using my improved fire bars are firstly
the bars produce perfect combustion by heating the air and discharging the same
behind the bridge thus consuming smoke and economising fuel; secondly the bars
being solid can be made at a lower cost than any of the fire bars by which the
same results as to combustion are claimed to be obtained; thirdly my improved
fire bars are easy adaptable to existing furnaces; fourthly the solid construction
of my fire bars gives them great durability which is increased by the arrangement
of the air inlet passages as herein described causing the cold air entering the
chambers between the bars to impinge against the upper parts of the bars where
they usually burn away.
My improved fire bars enable the fire grate to be adapted to various classes of
fuel and any system of draught, as the fire bars can be so made that the air is
heated and discharged behind the fire bridge between every alternate bar or between
each bar; and air can be admitted to the fuel above the fire grate between each
bar or between every alternate bar; or one of the last said arrangements may be
applied to the front part of the grate and the other to the back.
I will describe my invention by referring to the accompanying drawings on
which
Fig. 1 is a side elevation partly in section and Fig. 2 is a cross section of a pair

page_text: of fire bars constructed according to this invention, one of the fire bars being
shewn broken away so as to expose the interior surface of the other bar;
Figs. 3 and 4 are similar views to Figs. 1 and 2 but illustrating modifications
of my invention;
Fig. 5 is a plan of three pairs of the said fire bars such as shewn in Figs. 3 and 4
one of the bars being broken away so as to shew the inclinel surface of the
other bar;
Fig. 6 shews separately one of the loose pieces which are employed in the fire
bars shewn by Figs. 3, 4 and 5 to form the inclined surfaces and air inlets;
Fig. 7 is a cross section of a pair of my improved fire bars illustrating a slight
modification;
Fig. 8 is a cross section of three bars illustrating a modified form of the fire bar
represented by Figs. 1 and 2;
Fig. 9 is a side elevation partly in section and Fig. 10 is a cross section of a
further modification of my invention;
Fig. 11 is a side elevation partly in section and Figs. 12 and 13 are cross
sections of a pair of fire bars constructed according to a further modification of
my invention;
Fig. 14 is a side elevation partly in section and Fig. 15 is a cross section of a
further slightly modified form of this invention;
Figs. 16 and 17 shew separately two of the loose pieces which are used in the
bar shewn by Figs. 9 and 10 to form the said inclined surfaces and air inlets.
The same letters of reference indicate the same or corresponding parts in all the
figures of the drawings.
In the example of my invention shewn by Fig. 1 each of the two fire bars A' A'
is cast or wrought with a projecting rib a' a' running along the top these ribs meeting
together or being at a short distance apart (when the bars are placed together) and
thus forming a chamber e in the upper part of the bar through which air can enter
at the fire door end b and pass along the chamber e as indicated by the arrows and
out behind the fire bridge C. The bottom of this chamber is formed of a series of
inverted V-shaped inclined projections or ribs marked a' (in this example cast with
the bars) the lower edges at of which are at short distances apart, so that when the
bars A A² are placed together in the furnace the small spaces a' between the lower
edges a will form openings along the bottom of the bar to admit air from the ashpit
to the chamber or enclosed space e between the bars A' A which air is by the
inclined surfaces of the projections a³ directed against the upper side a¹ a² of the
bars which are the hottest, so that the air will thus be thoroughly heated on its
passage to the back of the bridge. Any small ashes falling through the ribs a' a'
into the air chamber e cannot lodge on the bottoms of the same as such ashes will
fall down the inclined surfaces a³ and through the bottom openings a³ into the
ash pit.
It will be evident that the said inclined projections a³ may be constructed and
arranged in various ways without departing from the nature of my invention, for
instance as shewn in Fig. 1 the said inclined projections as are cast on the adjacent
surfaces of both of the bars A' A' so that the inclined projections on one bar meet
the inclined projections on the other bar as shewn in cross section in Fig. 2.
In Fig. 3 the said inclined projections are made in the form of hollow triangles a
one of which is shewn separately by Fig. 6 which are hung on pegs d projecting
from the internal side of the bar at the proper distances apart. Or as shewn also
in Fig. 3 the V-shaped or inclined projections may be made in the form of separate
inverted Vs a hung on the pegs d. In Fig. 7 the pins d on which the inclined
parts a (or a) are hung pass right through the two bars A¹ A².
Fig. 5 shews how the bars fit together side by side and illustrates three pairs of
bars marked respectively A A A A A A the bar A¹ being broken away to
shew the inclined projections a' a' of the bar A.
The meeting surfaces of the ribs a' a² may be rebated as shewn in Fig. 7 so as

page_text: of the bar.
the better to fit together and prevent ashes falling through into the hollow interior
Instead of the top ribs such as a' a' being formed on only one side of the fire
bar, ribs such as a' a² may be formed on both sides of the top of the bars as shewn
by Fig. 8. In this case the hars do not have to be arranged in pairs to form the
air chambers but there is an air chamber or cavity e between every two adjacent
bars, and the inclined parts such as a or a or a' or a are arranged between every
two adjacent bars.
The said inclined air-inlet surfaces may be formed by inverted V-shaped pieces a
(see Figs. 9, 10, 16 and 17) which are cast or wrought separate from the bar itself
and are made with feet a containing air inlet holes at the said feet being arranged
to fit upon ribs a' which are formed along the bottoms of the bars A' A at a short
distance apart so as to leave space for the air to enter. Two forms of these inclined
V-shaped parts are shewn separately by Figs. 16 and 17.
The upper parts a' a of the bars may either come close together as in Figs. 2,
4, 7 and 10 or these ribs a' a' may be arranged to be at a short distance apart as in
Figs. 8, 12 and 13 so that some of the hot air from the chambers e can pass up
between the bars to the fuel burning thereon.
The projecting inclined ribs a forming the inclined surfaces which are cast on
the bars, may if desired be made to fit one within the other as shewn in Figs. 12
and 13 so as the better to prevent air entering the chambers e except through the
proper inlet holes a. The bars A' A' may if desired be gradually thickened on
the lower edges as shewn in Figs. 14 and 15 their adjacent sides being inclined
slightly where the V-shaped ribs a are formed so as to diminish the area of the air
inlet openings.
When two or more bars are placed end wise in a furnace their ends inay be made
to fit one within the other as shewn on the left hand side of Fig. 3 where the bars a
are shewn entering the ends of the bars A' A' so that there will be a continuous
air passage from the bars A' through the bars A¹ A to the back of the fire
bridge.
The fire door end 6 of the bars may either be open so that part of the air enters
through the open ends, or these ends of the bars may be closed and all the air be
directed up through the openings a³.
As with some other kinds of hollow fire bars at present in use a damper may if
desired be applied at the fire bridge ends of the bars to regulate the discharge of
hot air behind the bridge, this damper being worked by a rod passing along the ash
pit to the front of the furnace, but as this damper forms no part of my invention
and is well known I have not thought it necessary to illustrate the same on my
drawings.
It will be evident that instead of the sides of the inclined parts at a a' a being
straight as shewn in Figs. 1, 3, 6, 9, 11, 14, 16 and 17 the sides of these inclined
parts may be curved as shewn for instance by Figs. 18 and 19.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
1. Solid furnace bars so constructed that when placed side by side in a furnace
they form air chambers between the bars by which chambers the air is heated and
conveyed behind the bridge, said chambers having inverted V-shaped or inclined
bottom air inlet openings into the ashpit through which air enters the chambers and
impinges on the upper parts of the bars and the dust can fall from the chambers
into the ash pit, ali substantially as hereiubefore described with reference to the
accompanying drawings.
2. Furnace bars of the kind denoted under Claim 1 made with longitudinal
projecting ribs such as a' a' along the top in combination with inclined side projec
tious such as a a' a' so arranged that when two of the bars are placed together

page_text: side by side they form an open ended chamber with inclined air inlet openings at.
the bottom for the purposes and substantially as hereinbefore described and illus-
trated by the accompanying drawings.
Dated this 16th day of March 1907
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.