Improvements in Furnaces for Steam Boilers and other Purposes.
Year: 1885

page_text: Improvements in Furnaces for Steam Boilers and other
Purposes.
I, HENRY THOMPSON, of N° 33, Alwyne Road, Canonbury, in the county of
Middlesex, Builder, do hereby declare the nature of the said invention for
"IMPROVEMENTS IN FURNACES FOR STEAM BOILERS AND OTHER PURPOSES," to be
as follows:-
This Invention relates to improvements in the construction of furnaces suitable
for steam boilers, baker's ovens and other purposes, whereby the escape of smoke
to the chimney is almost, if not entirely, prevented.
The fire bars of the furnace are made to extend from the front of the grate to
the back thereof where the inner ends are turned upwards and extend, or nearly so,
to the crown or top of the furnace, the said bars are hollow, that is to say, they
have passages formed therein from the front ends to the back portions thereof.
The front ends of the said bars are left open in front of the furnace and the rear
ends are closed. In the back surface of those portions of the bars which are bent
up and constitute the back of the grate I make one or more perforations. At
a short distance behind the back of the grate is a division plate or partition
extending downwards from the crown of the furnace to a point below the hori-
zontal portions of the fire bars. To the lower end of the said division plate or
partition is attached a horizontal plate which extends forward nearly to the front
of the ash pit and divides the latter horizontally, as will be well understood. The
furnace and the ash pit are closed at the front, but are provided with suitable
regulators for the admission of air, if desired. The open front ends of the hollow
fire bars are also provided with means by which the passage of air through the
same may be regulated.
A sliding plate is provided for regulating the distance between the door of the
ash pit and the front of the before mentioned horizontal division plate.
The action of furnaces constructed as hereinbefore described is as follows.
The products of combustion from the fire pass between the backs of the bars into
the space in front of the upfight division plate or partition and there become mixed

page_text: with heated air which enters the said space through the perforations in the hollow
bars and the whole travel downwards until they come into contact with the
horizontal division plate when they are directed to the front of the ash pit
travelling between the underside of the fire bars and the upper surface of the
horizontal division plate the smoke being almost, if not entirely, consumed. The
products of combustion on reaching the front of the ash pit enter the space below
the horizontal division plate and are conducted thence to the flue.
For the convenience of cleaning the flues, or, the tubes, in the case of tubular
boilers, the division plates may be made movable or may be provided with suitable
doors.

page_text: urposes.
I, HENRY THOMPSON, of No 33, Alwyne Road, Canonbury, in the county of
Middlesex, Builder, 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 :—
My said Invention relates to improvements in the construction of furnaces
suitable for steam boilers, bakers' ovens, and other purposes, by means of which
improvements the escape of smoke to the chimney is almost, if not entirely,
prevented.
I will now proceed to describe this invention with reference to the accompanying
drawings, in which the same letters indicate like parts in all the Figures. Figure 1.
is a front of a boiler provided with two furnaces constructed in accordance with
this invention, the door and front plate of one of the furnaces are shown removed;
and Figure 2. is a longitudinal section through one of the furnaces.
The fire bars A. of the furnace are made to extend from the front of the grate
to the back thereof where the inner ends are turned upwards and extend, or
nearly so, to the crown or top of the furnace. The said bars are hollow, that is to
say, they have passages formed therein from the front to the back. The front
ends of the said bars are left open in front of the furnace and the rear ends are
closed. In the back surface of those portions of the bars, that are bent up and
constitute the back of the grate, I make one or more perforations. At a short
distance behind the back of the grate is a division plate or partition D. extending
downwards from the crown of the furnace to a point below the horizontal portions
of the fire bars. To the lower end of the said division plate or partition is attached
a horizontal plate E. which extends forward towards the front of the ash pit and
divides the latter horizontally. The ash pit is closed by a door, which is arranged
in front, as shown at Figure 2., or, it may be arranged immediately below the
mouths of the fire bars in front of which is a dead plate I., as shown in Figure 3,
or, in some cases, I arrange it still further in the ash pit, so that the air from
the front thereof may pass up through the fore ends of the fire bars into the
furnace. The doors closing the fronts and also the open ends of the fire bars
are provided with means by which the passage of air through the same can be
regulated.
A sliding plate is provided for regulating the distance between the door of the
ash pit and the front of the plate E.
The action of furnaces constructed as herein before described is as follows:-The
products of combustion pass between the backs of the bars A. into the space B. in
front of the division plate or partition D. and there become mixed with heated air
which enters the said space B. through the perforations in the hollow bars, and the
whole travel downwards until they come into contact with the division plate E.
when they are directed through the space C. towards the door of the ash pit, the
smoke being almost, if not entirely, consumed. The products of combustion on
reaching the front of the plate E. enter the space F. and are conducted thence to
the flue.

page_text: For the convenience of cleaning the flues, or the tubes in the case of tubular
boilers, the division plates may be made moveable or may be provided with
suitable doors.
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 :-
The construction of furnaces with the hollow bars A. the chamber B. the division
or partition D. the horizontal plate E. and flue F., substantially as and for the
purposes herein before described and shown in the accompanying drawings.
VAUGHAN & SON,
Agents for the Applicant.