IMPROVEMENTS IN APPARATUS FOR CONSUMING SMOKE AND PROMOTING COMBUSTION IN THE FURNACES OF STEAM BOLLERS.
Year: 1876

page_text: LETTERS PATENT to Charles Mace and John Brewster, both of Sunderland, in
the County of Durham, for the Invention of "IMPROVEMENTS IN APPARATUS
FOR CONSUMING SMOKE AND PROMOTING COMBUSTION IN THE FURNACES OF
STEAM BOLLERS.
"
Scaled the 1st September 1876, and dated the 1st July 1876.
PROVISIONAL SPECIFICATION left by the said Charles Mace and John
Brewster at the Office of the Commissioners of Patents on the 1st July 1876.
CHARLES MACE and JOHN BREWSTER, both of Sunderland, in the County of
Durham. "IMPROVEMENTS IN APPARATUS FOR CONSUMING SMOKE AND PROMOTING
COMBUSTION IN THE FURNACES OF STEAM BOILERS."
The Invention has for its object improvements in the means of consuming smoke
and effecting more perfect combustion in the furnaces of steam boilers. To attain
these results we employ a fire-door balanced upon trunnions having a common
horizontal axis, about which the said fire-door is free to move in the arc of a circle
of which the fire-door itself is in section a segment; the above-mentioned trunnions
taking into trunnion boxes in and on the door frame. The fire-door is constructed
in the form of a longitudinal segment of a cylinder consisting of two plates, one a
flat plate with perforations at-the top, and the other a curved plate placed with its
concave side towards the flat plate so as to form an air course between them..
Perforations are formed.in the lower portion of the curved plate, whereby a flow of
air is allowed to enter into the furnace to aid in effecting more perfect combustion,
and consequently consumption of smoke. The curved plate may be either per-
manently fixed to or detachable from the flat plate. We also in some cases place a
slotted roller along the bottom edge of and pivotted into the ends of the aforesaid
fire-door, the slots being used when necessary for the admission of fire-irons or the
further supply of air.
From the back of the fire-door project two curved arms at right angles to the
door and parallel to each other, each arm is mounted upon one of the before-
mentioned trunnions, and the outer extremities of the arms are connected by a bar
which balances the fire-door, so that it will stand in any required position, the bar
also serves as a handle by which to open the fire-door for the admission of fuel.
The fire-door hangs in front of an opening in a metallic frame.
upper part of the frame are made hollow at the back towards the
The sides and
interior of the

page_text: furnace, and in the hollow are placed fire-bricks suitably moulded so as to form a
back to the furnace, the lowest brick on each side of the frame is perforated for the
passage of air.
We also leave a space between the fire-brick back and the front
part of the hollow metallic frame so as to form an air course at the back of the
fire-bricks, into which air passes by a ventilator placed at the upper part of the
front of the metallic frame and enters the furnace by the perforated bricks at the
bottom, thereby contributing to the thoroughness of combustion and consumption of
smoke.
At the sides of the opening formed through the frame are the trunnion boxes to
receive the trunnions of the doors, and at the top and bottom of the opening we
affix curved plates concentric with the trunnions. In some cases we attach stops to
the upper curved plate to limit the movement of the door in that direction, but in
other cases we dispense with these stops and leave the door free to move either
upwards or downwards.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Charles Mace and John Brewster in the Great Seal Patent Office on the
1st January 1877.
25
CHARLES [MACE and JOHN BREWSTER, both of Sunderland, in the County of
Durham. IMPROVEMENTS IN APPARATUS FOR CONSUMING SMOKE AND PROMOTING
COMBUSTION IN THE FURNACES OF STEAM BOILERS."
This Invention has for its object improvements in the means of consuming smoke
and affecting more perfect combustion in the furnaces of steam boilers. To attain
these results we employ a fire-door balanced upon trunnions having a common
horizontal axis, about which the said fire-door is free to move in the arc of a circle
of which the fire-door itself is in section a segment; the above-mentioned trunnions
taking into trunnion boxes in and on the door frame. The fire-door is constructed
in the form of a longitudinal segment of a cylinder, and consists of two plates, one
a flat plate with perforations at the top, and the other a curved plate placed with
its concave side towards the flate plate so as to form an air course between them.
Perforations are formed in the lower portion of the curved plate, whereby a flow
of air is allowed to enter into the furnace to aid in effecting more perfect com-
bustion, and consequently consumption of smoke. The curved plate may be either
permanently fixed to or detachable from the flat plate. We also in some cases place
a slotted roller along the bottom edge of and pivotted into the ends of the afore-
said fire-door, slots being used when necessary for the admission of fire-irons or the
further supply of air; the fire-door may, however, be used without this roller.
From the back of the fire-door project two curved arms at right angles to the
door and parallel to each other, each arm is mounted upon one of the before-
mentioned trunnions, and the outer extremities of the arms are connected by a
bar which balances the fire-door so that it will stand in any required position, the
bar also serves as a handle by which to open the fire-door for the admission of fuel.
The fire-door hangs in front of an opening in a metallic frame. The sides and
upper part of the frame are made hollow at the back towards the interior of the
furnace, and in the hollow are placed fire-bricks suitably moulded so as to form a
back to the furnace, the lowest brick on each side of the frame is perforated for the
passage of air. We also leave a space between the fire-brick back and the front
part of the hollow metallic frame so as to form an air course at the back of the fire-
bricks, into which air passes by a ventilator placed at the upper part of the front of
the metallic frame and enters the furnace by the perforated bricks at the bottom,
thereby contributing to the thoroughness of combustion and consumption of smoke.
At the sides of the opening formed through the frame are the trunnion boxes to
receive the trunnions of the doors, and at the top and bottom of the opening we
affix curved plates concentric with the trunnions. In some cases we attach stops to

page_text: the upper curved plate to limit the movement of the door in that direction, but in
other cases we dispense with these stops and leave the door free to move either
upwards or downwards.
In order that the nature of the said Invention may together with the means by
which it is accomplished be more clearly understood we append to this Specification
a Sheet of Drawings showing apparatus constructed as above described, and having
figures and letters of reference marked thereupon, the same letters being used to
denote similar parts in each Figure.
In these Drawings Figure 1 represents a complete back view of the metallic
portion of our improved fire-door and frame. Figure 2 represents a sectional view
of Figure 1 through A, A. Figure 3 represents the curved detachable plate of the
fire-door. Figure 4 represents an end elevation of Figure 3. Figure 5 represents
a sectional view of Figure 6 through B, B. Figure 6 represents a front elevation of
our fire-door and frame complete.
all is the flat plate of the door with the perforations at the top; a² is the curved
plate of the door with the perforations at the bottom; b is the slotted roller; c, the
attachments of curved plate; d, strengthening ribs of curved plate; f, balance handle
of door; g, ventilator at top of door frame; h, stops on upper curved plate of door
frame; i, one of fire-bricks forming back; k, hollow metallic frame; m, trunnion
boxes; n, the trunnions; o, the curved arms.
Having thus described the nature of our Invention, and the means by which it is
effected, we wish it to be understood that we claim-
First. The construction of our improved furnace door and door frame, substantially
as herein-before described.
Second. The suspension of the fire-door of furnaces on trunnions, substantially as
herein-before described.
In witness whereof, we, the said Charles Mace and John Brewster, have
hereunto set our hands and seals, this Twenty-sixth day of December, in
the year of our Lord One thousand eight hundred and seventy-six.
MACE
(re)