Year: 1898

page_text: We, HARRY SCHOFIELD, of 1A, Briantwood Road, Drayton Park, N., Engineer,
and OLIVER PRESCOTT MACFARLANE, of 7, Hartham Road, Camden Road, N.,
Accountant, do hereby declare the nature of this invention to be as follows;-
-
Our invention relates to furnace bridges and has for its object, to so construct
the said bridges that they shall be easily built, strong, and not liable to
collapse; and also to provide them with a chamber or chambers for heating to a
high temperature a draught of air passing therethrough directly into the flue
behind the said bridge, to effect the more complete combustion of the uncon-
sumed smoke passing from the furnace into the said flue.
According to our invention we construct the bridge in the required situation,
of bricks of special form. Some of these bricks have projections thereon and
others have corresponding recesses to receive the said projections; or the bricks
may have both projections and recesses, or may be constructed with a projection
at one end or side and a recess at the opposite end or side thereof; or bricks in
certain positions may have only one projection or recess. The said projections
and corresponding recesses may be of any convenient form so long as the projections
fit the recesses. The bricks are so. arranged that no two joints between the
bricks in contiguous layers are in the same straight line, so that an effective
bond is produced without necessitating the use of cement.
Within the bridge we form a chamber or chambers communicating with an air
inlet or air inlets situated on the furnace side of the bridge below the level of
the fire bars. A number of passages pass from this chamber to the rear side
of the bridge, forming outlets for the air passing threfrom into the flue; these
outlets being arranged so as to distribute the air and cause it to mix with the
unconsumed smoke passing over the bridge into the flue. Comparatively cool
air is thus admitted to the said chamber and after becoming heated to a high
temperature therein is discharged so as to mix with and effect the more com-
plete combustion of the unconsumed smoke in the flue.
The air supply may be regulated by slides covering the inlets or by other
convenient means, or may be augmented by means of a jet of steam forced into
the inlets.
Data 411041.
of Avonot 1908
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.

page_text: Improvements in Furnace bridges.
We, HARRY SCHOFIELD, of 1A, Briantwood Road, Drayton Park, Engineer,
and OLIVER PRESCOTT MACFARLANE, of 7, Hartham Road, Camden Road,
Accountant, both in the County of London, 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:-
1
Our invention relates to furnace bridges and has for its objects, to so construct
the said bridges that they shall be easily built, strong, and not liable to
collapse; and also to provide them with a chamber or chambers for heating to a
high temperature a draught of air passing therethrough and issuing directly into
the flue behind the said bridge, to effect the more complete combustion of the
unconsumed products of combustion passing from the furnace into the said flue.
An essential feature of the invention consists in constructing the furnace bridge
of bricks provided with projections. and recesses, the projections and recesses in
contiguous bricks being adapted to engage in such manner as to produce an
effective bond without necessitating the use of cement.
A further essential feature of the invention consists in forming a heating
chamber within the bridge, which heating chamber is provided with means where-
by air is admitted thereto from below the fire bars on the furnace side and dis-
charged therefrom in a heated condition into the flue, so as to meet and assist
in the more complete combustion of the unconsumed products of combustion
passing over the bridge.
In order that our invention may be clearly understood and readily carried into
effect we will now proceed to describe the same more fully with reference to the
accompanying drawings in which :-
Figure 1 is a front elevation, Figure 2 is a rear elevation and Figure 3 is a
plan with part of the flue casing removed, of a furnace bridge constructed accord-
ing to our invention and arranged in a boiler flue.
Figure 4 is a section on line - Figure 1, showing the bridge and part of the
furnace and flue.
Figures 3 and 4 are drawn to a larger scale than Figures 1 and 2.
A is the flue casing or tube, 13 is the furnace bridge, C is the furnace, and
D is the flue. b b are the bricks or blocks of which the bridge is constructed
and is the key block. The blocks are provided with projections and
recesses 62. The projections 6 engage with the recesses 2 in contiguous blocks
and make an effective bond without the use of cement. E is an air chamber
formed in the upper part of the bridge B. ee are air inlet passages connecting
the chamber E with the ash pit or space below the fire bars of the furnace,
and e¹ el are air outlet passages connecting the chamber E with the flue D.
The chamber E becomes heated by the flames passing over the bridge. Fresh
air, which has already been heated in its passage through the ash pit, enters the
said chamber through the passages e e, where it becomes intensely heated. This
heated air is then distributed evenly, through the passages el e¹, into the flue at
the rear side of the bridge where it meets and mingles with the unconsumed
products of combustion passing over the bridge, and effects the more complete
combustion of the said unconsumed products; thus increasing the efficiency of
the furnace.
It is obvious that the positions of the projections and recesses in the bricks b
as well as the shape of the said bricks may be somewhat varied without departing
from our invention.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A furnace bridge constructed of bricks provided with projections and recesses
adapted to engage with one another, substantially as described for the purpose
specified.
2. A furnace bridge having an internal chamber provided with means for the
ingress and egress of air, substantially as described, for the purpose specified.
3. A furnace bridge, substantially as described with reference to the accom-
panying drawings for the purpose specified.
Dated this 7th day of June 1899.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.