Improvements in Furnace Grates for the Better_Consuming of Smoke and the Better Combustion of Fuel.
Year: 1888

page_text: Date of Application, 15th June, 1888
Complete Specification Left, 15th Mar., 1889-Accepted, 15th July, 1889
PROVISIONAL SPECIFICATION.
Improvements in Furnace Grates for the Better_Consuming of
Smoke and the Better Combustion of Fuel.
WILLIAM FRASER Engineer 6 Livery Street Birmingham do hereby declare the
nature of this invention to be as follows:-
The object of this Invention is to obtain perfect combustion in the burning of
Fuel in any kind of Furnaces or elsewhere, & also to utilise & consume all gas
that escapes in the way of smoke, for two reasons, first, ecomomy. Second, to.
prevent smoke nuisance."
To obtain these results I convert the ordinary plain furnace bottom into a
corrugated one, or a series of corrugations running longitudinally (or otherwise)
from back to front or from end to end of the furnace, thus the surface or area of the
furnace bottom can be increased to almost any extent desired, by simply increasing
the height of the corrugations. This arrangement of corrugations provides for the
requisite amount or quantity of Air being admitted above as well as below the fuel
for the purpose of ensuring perfect combustion.
When the fuel is thrown into the furnace in falls into the longitudinal hollows or
recosses & there remains untill consumed the top or uppermost parts of the corru-
gations remains always uncovered with fuel, they being so constructed that the fuel
cannot remain upon them or cover them when the hollows or recesses are filled (but
nothing more) with fuel.
The object in keeping the fuel below & not above the level of the top or uppermost
parts of the corrugations, is to admit a free current of air all along the top of the
corrugations. The burning fuel being below the level of the air current, thus the
fuel is supplied with the necessary air required above for perfect combustion. The
air below the fuel being admitted thro' sufficient sized holes or openings along the
bottom & sides of the corrugations these openings being always more or less or
generally covered with fuel, thus the fuel is supplied with air above & below &
distributed equally all over the furnace.
It is obvious that the bottom of a furnace can be made in almost any shape other
than corrugated, but what I want to note particularly is the principle of distributing
the air thro the fuel & in the furnace as already described. The corrugated furnace
bars are so made & constructed that the air can be drawn in at either end or
elsewhere & conveyed to any desired place either above or below the bars or front
or back of the furnace or at the bridge or elsewhere for the purpose of causing the
better combustion of the gas generated within the furnace.
It is also obvious that the heated air from the corrugated flues in the bars may be
inserted thro the brick work or other fittings, in any suitable way for the better &
more complete combustion of the fuel, but what I want to particularly note, is, the
heating of air by means of corrugated bars or corrugated holes thro' or under or
above same for the purposes already described.
14th June 1888.
WILLIAM FRASER.
COMPLETE SPECIFICATION.
Improvements in Furnace Grates for the Better Consuming of
Smoke and the Better Combustion of Fuel.
I, WILLIAM FRASER of 77 Colmore Row, Birmingham in the County of Warwick,
5 Engineer, do hereby declare the nature of this invention and in what manner the
[Price 8d.1

page_text: same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention has for its object the consumption of smoke, and the better com-
bustion of fuel, and consists 1st. in an improved construction of fire bar-2ndly in
providing furnace grates with combustion bars, or combustion side plates, having
disposed between them, intermediate flat bars-3rdly in the arrangements of furnace
grates, in respect to the bars.
Figure 1 of the accompanying drawings represents in end elevation, a steam boiler
flue, provided with a furnace grate and fire-bars, constructed and arranged according
to my said invention.
It will be seen that the bars, which are arranged zig-zag, or pyramidal in cross
section, have the air spaces, or divisions between the lars, directed vertically, and by
such construction of bars, the superficial air surface within a furnace grate, is greatly
increased.
a is the flue of a furnace, b the fire-grate thereof, c the ash-pit, and d are the fire-
bars arranged horizontally across the said fire-grate, and with the perforated sides
inclined at an angle in a zig-zag manner, whereby air supply to the fuel of the said
furnace, is greatly increased, and combustion thereby proportionately enhanced, and
smoke prevented.
It will be understood that the fuel supplied, upon the said bars, which are directed
from front to rear of the fire-grate, falls within the ruts or channels, leaving the tops
or apexes of the said bars naked or exposed, and wherethrough the spaces, or divisions
thereof, air is supplied to the top of the fuel, and in and among the products of
combustion.
Figure 2 represents a furnace grate, constructed according to another form of my
invention, for enlarging the air supply to the furnace grate.
a is a boiler flue, 6 the fire-grate thereof, c the ash-pit, and d the fire-bars, with the
tops disposed in a concave direction.
Figure 3 represents in vertical section, partly in elevation, a steam boiler and
furnace grate, with the latter provided with fire-bars.
Figure 4 is an end elevation of the same, and figure 5 is a transverse vertical section
of the furnace grate and flue. Figure 6 is a plan of the fire-bars of the furnace-
grate, and figure 7, is a side elevation of the furnace-grate, showing the full length of
one of the combustion bars.
a¹ is a steam boiler, and a the flue thereof; the fire grate, c the ash-pit, d the
intermediate fire-bars, and e the combustion bars, inclined upwards and inwards
towards the sides of the said fire-grate, so as to form at the back of the said
combustion bars, plates or longitudinal slabs, air spaces e², from whence air inwardly
passes to the fire-grate through holes or piercings e³. These said combustion bars
are opened on their undersides to the ash-pit, and extend upon the two opposite sides
of the furnace to the entire extent of its length; so that heated air which accumulates
within the interiors of the chambers enclosed between the inside of the said bars, and
the inside of the flue or furnace, is conducted inwardly, through the holes or
piercings e³, and from thence on to the top of the burning fuel in the furnace, which
ensures complete combustion, and the furnace smokeless.
The combustion bars or side plates are provided with rests, directed at intermediate
distances along their insides, so as to effectually support the said bars or plates.
Figure 8 represents side combustion bars, with intermediate flat bars applied to a
square furnace, instead of a circular flue furnace, as in the last arrangement.
Figure 9 represents another form of combustion bar or side plate.
In this modification, the bar or plate has open slots near the base, and diagonally
or other directed holes from the said slots to the top side thereof.
The fuel supplied to the furnace, comes up to the tops of the slots or gaps, whilst
the small holes or piercings supply air to the top side of the burning fuel.
In figure 10, double rows of oblique piercings, supply air to the top of the fuel,
and below the fuel, and that the intermediate holes below the fuel, come up to the
fuel level only of the furnace grate.

page_text: Figure 11 represents in front elevation, another form of combustion side bar or
plate. Figure 12 is a cross section of the same, and figure 13 is an underside
edge view, showing the inside supports, the corrugated edge and other parts of it.
e is the combustion plate, e are diagonally directed slots, et are taper flutes or
channels, directed from the base to the fuel line of the said plate, and e³ are long
gaps or openings between the flutes or channels.
When in use, the combustion bar or plate, which is an exterior shell resting upon
the two opposite sides of the furnace, supplies air to both above the burning fuel, and
at the sides of the burning fuel. Thus, the upper slits or openings e supply air
above the fuel, so also do the upright channels e, as they are so arranged, that the
air creeps up the channels, and around the fuel, which comes into direct contact
with the said bars.
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
First. Making the top side surface of a furnace-grate, longitudinally corrugated,
channelled or undulatory, whereby a large air surface is presented to the fuel, and
perfect combustion effected, as set forth in figure 1.
Secondly. Forming a furnace-grate of incline-sided or continuous V sectioned
bars, which when arranged and put together, make standing up bars, with trenches or
channels between them, as set forth in figure 1.
Thirdly. Concaving or downwardly curving the bed of a fire-grate, as set forth
in figure 2.
Fourthly. Arranging longitudinally at the two opposite sides of a furnace grate,
combustion bars, plates, or rearwardly open shells, either pierced, slotted or channelled,
or both pierced or slotted and channelled, as set forth in figures 3 to 13 both
inclusive.
Fifthly. The improvements in the construction of fire-grates, as herein-described
and set forth in figures 3, 4, 5, 6, 7 and 8, whereby perfect combustion of fuel is
effected, and smoke prevented.
Dated this Fourteenth day of March 1889.
WILLIAM FRASER.
By George Barker,
Agent for Applicant.