IMPROVEMENTS IN STEAM BOILER FURNACES AND OTHER FURNACES
Year: 1877

page_text: LETTERS PATENT to Conrad Christian Severin Knap, of Gravelly Hill, near
Birmingham, in the County of Warwick, Mechanical Engineer, for the Inven-
tion of "IMPROVEMENTS IN STEAM BOILER FURNACES AND OTHER FURNACES."
Sealed the 28th March 1877, and dated the 15th January 1877.
PROVISIONAL SPECIFICATION left by the said Conrad Christian Severin
Knap at the Office of the Commissioners of Patents on the 15th January
1877.
CONRAD CHRISTIAN SEVERIN KNAP, of Gravelly Hill, near Birmingham, in the
County of Warwick, Mechanical Engineer. "IMPROVEMENTS IN STEAM BOILER
FURNACES AND OTHER FURNACES."
My Invention consists, first, of the mechanical arrangement of parts herein-after
described for feeding fuel into steam boiler furnaces and other furnaces.
At the front of the furnace is a fuel hopper, the lower contracted end of which
opens into a horizontal cylindrical chamber or case, in which chamber or case a
drum having a slow rotatory motion works. The side and a portion of the bottom
of the said chamber or case opens into the front of the furnace by means of a
delivery spout having a concave bottom. In the cylindrical surface of the said
drum one, two, or more depressions or recesses is or are made. I prefer to make a
depression or recess at opposite points of the drum, but I do not limit myself thereto.
When by the rotation of the drum one of the depressions or
recesses comes
opposite the lower contracted end of the fuel hopper, fuel from the said hopper falls
into the said depression, and by the continued motion of the drum the fuel in the
depression is carried to the mouth of the delivery spout herein-before described,
into which spout the fuel is emptied, and by which it is conducted to the front part
of the grate or fire-bars of the furnace.
That part of the inner face of the cylindrical chamber or case to which the
charged depression in the drum is presented, immediately it leaves the contracted
end of the hopper, is made convex through its whole length, the said convex part,
constituting a crushing surface or shoulder, against which shoulder any large coal
carried by the drum is crushed on its way to the delivery spout. The quantity of
fuel delivered into the furnace at each rotation of the drum depends upon the
number and size of the depressions or recesses in its cylindrical surface. The feeding

page_text: drum is fixed upon a shaft driven in any convenient way. This shaft may also
serve to work the mechanism next described.
My Invention consists further of the mechanical arrangement of parts herein-
after described for giving a reciprocating motion and a rising and falling motion to
the fire-bars of furnaces. Each alternate fire-bar of the furnace grate is prolonged
at its front end, and is carried by a horizontal shaft at the front of the furnace.
The rear ends of the said fire-bars are mounted upon a rocking shaft in the usual
manner. On each end of the feeding drum shaft herein-before described is an
excentric provided with a clip and clip rod, each of the said rods passes to the
foundation of the furnace, and its lower end is centred by a link or crank arm to a
fixed base plate. The ends of the horizontal shaft carrying the front ends of the set
of fire-bars are supported in bosses or enlargements made at about the middle of the
said excentric rods.
As the feeding drum shaft rotates, a slow reciprocating and a rising and falling
motion is given to the fire-bars through the excentrics, excentric rods, and the hori-
zontal shaft supporting the front ends of the fire-bars, and the fuel fed on to the said
fire-bars is thereby broken up, and its combustion promoted and gradually advanced
from the front end to the rear end of the furnace.
Instead of giving motion to alternate fire-bars only of the furnace grate, the
whole of the fire-bars may have motion given to them by duplicating and modifying
the mechanism described. In this case the mechanism is so arranged that while
one set of fire-bars is moving in one direction the other set is moving in the opposite
direction.
Although I have described the feeding mechanism and the mechanism for moving
the fire-bars as worked from one shaft, and which arrangement I prefer to employ,
yet the respective mechanisms described may be worked from independent shafts.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Conrad Christian Severin Knap in the Great Seal Patent Office on
the 22nd June 1877.
CONRAD CHRISTIAN SEVERIN KNAP, of Gravelly Hill, near Birmingham, in the
County of Warwick, Mechanical Engineer. "IMPROVEMENTS IN STEAM BOILER
FURNACES AND OTHER FURNACES."
My Invention consists, first, of the mechanical arrangement of parts, herein-after
described, for feeding fuel into steam boiler furnaces and other furnaces.
At the front of the furnace is a fuel hopper, the lower contracted end of which
opens into a horizontal cylindrical chamber or case, in which chamber or case a
drum having a slow rotatory motion works. The side and a portion of the bottom
of the said chamber or case opens into the front of the furnace by means of a
delivery spout. In the cylindrical surface of the said drum one, two, or more
depressions or recesses is or are made. When by the rotation of the drum one of
the depressions or recesses comes opposite the lower contracted end of the fuel
hopper fuel from the said hopper falls into the said depression, and by the continued
motion of the drum the fuel in the depression is carried to the mouth of the
delivery spout herein-before described, into which spout the fuel is emptied and
by which it is conducted to the front part of the grate or fire-bars of the furnace.
That part of the inner face of the cylindrical chamber or case, to which the
charged depression in the drum is presented, immediately it leaves the contracted
end of the hopper, is made convex through its whole length, the said convex part
constituting a crushing surface or shoulder against which shoulder any large coal
carried by the drum is crushed on its way to the delivery spout. The feeding drum
is fixed upon a shaft driven in any convenient way. This shaft may also servo to
work the mechanism next described.

page_text: My Invention consists further of the mechanical arrangement of parts herein-
after described for giving a reciprocating motion and a rising and falling motion
to the fire-bars of furnaces. Each alternate fire-bar of the furnace grate is prolonged
at its front end, and is carried by a horizontal shaft at the front of the furnace.
The rear ends of the said fire-bars are mounted upon a rocking shaft or an ordinary
bearer in the usual manner. On each end of the feeding drum shaft, herein-before
described, is an excentric provided with a clip and clip rods. Or the said rods may
be connected to pins on crank plates on the drum shaft. Each of the said rods
passes to the foundation of the furnace, and its lower end is centred to a fixed base
plate. The ends of the horizontal shaft, carrying the front ends of the set of fire-
bars, are supported at or about the middle of the said excentric or crank rods.
As the feeding drum shaft rotates a slow reciprocating and a rising and falling
motion is given to the fire-bars through the eccentrics, eccentric rods, or crank rods,
and the horizontal shaft supporting the front ends of the fire-bars and the fuel fed
on to the said fire-bars is broken up and its combustion promoted, and the said fuel
is gradually advanced from the front end to the rear end of the furnace. The
whole of the fire-bars may be worked instead of alternate bars.
I will now proceed to describe, with reference to the accompanying Drawings,
the manner in which my Invention may be performed.
Figure 1 represents in front elevation, and Figure 2 in longitudinal vertical
section, a steam boiler or other furnace to which mechanisin coustructed according
to my Invention for feeding fuel to the fire-grate and for moving the fire-bars of
the said grate is applied.
Figure 3 is a horizontal section of the front end of the fire-grate, and exhibits my
arrangement for moving the fire-bars of the grate.
The same letters of reference indicate the same parts in Figures 1, 2, and 3.
I will first describe the arrangement for feeding the fuel to the fire-place of the
furnace At the front of the furnace is a fuel hopper a, the lower contracted end
of which opens into a horizontal chamber or case 6, 62, having the sectional form
best seen in Figure 2. In the said chamber or case b, b, a feeding drum c works,
the said drum having a slow rotatory motion given to it in the manner herein-after
described. The said drum c works closely against the front side b of the case, but
a narrow space is left between the cylindrical surface of the drum and the rear
side 2 of the said case. The upper end or top of the chamber or case b, 62, opens
into the hopper a, and the lower end or bottom of the said case opens into the front
of the furnace or fire-place d by the delivery spout c. In the cylindrical surface of
the rotatory drum c is a depression or recess c² running from end to end of the said
drum, but two or more similar depressions or recesses may be used if desired.
The inner face of the rear side 62 of the cylindrical chamber or case is made
convex near its lower end at b³, the said convex part be extending the whole length
of the side, and forming a crushing surface or shoulder for the purpose herein-after
explained. The feeding drum c is driven by a worm f on the horizontal shaft I,
gearing with a worin wheel h on the axis c³ of the said feeding drum (see Figure 1).
The shaft g of the worm f may be driven by a band passing over the driving
pulley i or by toothed gearing. By means of the worm gearing represented a slow
rotatory motion is given to the feeding drum c. When by the rotation of the said
drum c the depression or recess c² in it comes under the lower contracted end of the
fuel hopper a, fuel in the said hopper falls into the said depression, and by the
continued motion of the drum the fuel in the said depression c² is carried to the
mouth of the delivery spout e, into which spout it is emptied and from thence passes
to the front part of the fire-bars or grate of the furnace d. Should any large lumps
of coal be fed to the depression or recess c² of the feeding drum, the said lumps are
carried by the rotation of the said druin against the crushing shoulder or surface b
of the back part 2 of the case, by which shoulder the said lumps are crushed before
they are emptied into the delivery spout e. The said back plate 62 of the chamber
or case may either be stationary or capable of adjustment, but I prefer to make the
said back plate adjustable, as shown in the Drawing, for the purpose of increasing

page_text: or diminishing the space between it and the feeding drum, as may be required to
feed a greater or less quantity of fuel to the fire-grate. The said back plate or
surface bis suspended at its top on trunnions or centres at b* on which it is capable
of turning (see Figure 2). Connecting rods, one of which is shown at k, pass from
the lower ends of the back plate or surface b² to the front of the furnace. The
outer ends of the connecting rods are screwed, and screwed hand wheels / work
upon the said screwed ends. By turning the hand wheels in one or other
direction the back plate 62 may be adjusted nearer to or further from the feeding
drum c, and the space between the said drum and back plate increased or diminished
and the feeding of the fuel thereby regulated.
I prefer to make the feeding drum c of a series of discs, and to arrange the
depressions or recesses c² therein in a zig-zag form in the length of the drum.
The quantity of the fuel delivered into the furnace at each rotation of the feeding
drum e depends upon the number and size of the depressions c³ in its cylindrical
surface, and can be further regulated by adjusting the moveable back plate or
crushing surface 62, 6%. The face of the delivery spout e may be made of a block e²
fixed in the manner illustrated in Figure 2 to the framing of the front of the
furnace; m is a door underneath the rear end of the fire-grate, operated by the
hand lever m² for the removal of ash and refuse, and p is the ordinary furnace door
for hand firing when required.
I will now describe my improved mechanism for giving a reciprocating motion
and a rising-and-falling motion to the fire-bars of the furnace.
In the Drawing an arrangement for moving each alternate fire-bar is shown.
,, are the stationary fire-bars, and r, r, are the alternating fire-bars to which
motion is given. The front ends of the fire-bars r are prolonged beyond the sta-
tionary fire-bars q, and the said prolonged ends of the bars r are carried by the
horizontal shaft s. The rear ends of the said moveable fire-bars r are supported
upon the ordinary bearer t, or upon an ordinary rocking shaft in the usual manner.
On each side of the front of the furnace is a vertical connecting rod, bar, or lever u,
to which the ends of the horizontal shaft s carrying the fire-bars are connected.
On one end of the shaft c³ of the feeding drum c is a crank plate v, the crank pin w
of which is jointed to one of the connecting rods u, the other of the said con-
necting rods u being jointed to a similar crank pin w² made on the face of the worm
wheel by which the feeding drum c is driven, as represented. The upper ends of the
connecting rods u, u, may be jointed to the crank pins w, w², in the ordinary way;
or the upper ends of the said rods may be looped or slotted, and the crank pins
work in the looped or slotted ends as indicated in dotted lines in Figure 2. Or the
ends of the shaft may be furnished with excentrics and the upper ends of the rods
u, u, with clips to work upon the said excentrics. The lower ends of the rods
u, u, are forked, the forked ends sliding upon the pins x, x, at the base of the fur-
nace, the said pins x, x, constituting centres on which the lower ends of the rods
u, u, may turn. By the rotation of the feeding drum shaft c³ a slow reciprocating
and a rising-and-falling motion is given to the fire-bars r, r, supported on the shaft s
through the crank pins w, w², connecting rods u, u, and the said shaft 8, and the
fuel on the said fire-bars is thereby broken up, and its combustion promoted. The
fuel is also gradually advanced from the front end to the rear end of the furnace.
The throw of the crank pins w, w², (or their equivalents) may be made capable
of adjustment to regulate the longitudinal travel and vertical lift of the fire-bars to
suit different qualities of fuel being burnt in the furnace. I prefer so to arrange
the mechanism as to give one revolution per minute to the feeding drum c, and to
lift one set of fire-bars above the other set half an inch at their front ends, but I
do not limit myself thereto.
Instead of giving motion to alternate fire-bars only of the furnace grate the whole
of the fire-bars may have motion given to them by duplicating and modifying the
mechanism described and represented. In this case the mechanism is so arranged
that while one set of fire-bars is moving in one direction the other set is moving in
the opposite direction.

page_text: Although I have described and represented the feeding mechanism and the
mechanism for moving the fire-bars as worked from one shaft, and which arrange-
ment I prefer to employ, yet the respective mechanisms described and represented
may be worked from independent shafts.
Having now described the nature of my Invention, and the manner in which
the same is to be performed, I wish it to be understood that I do not limit myself
to the precise details herein described and illustrated, as the same may be varied
without departing from the nature of my Invention; but I claim as my Invention
of improvements in steam boiler furnaces and other furnaces,-
First. The arrangement or combination of the parts of mechanism, substantially
as herein-before described and illustrated in the accompanying Drawings, for feeding
fuel into the said furnaces.
Secondly. The arrangement or combination of the parts of mechanism, substan-
tially as herein-before described and illustrated in the accompanying Drawings,
for giving a reciprocating motion and a rising-and-falling motion to the fire-bars of
the said furnaces.
In witness whereof, I, the said Conrad Christian Severin Knap, have here-
unto set my hand and seal, this Eighteenth day of June, in the year of our
Lord One thousand eight hundred and seventy-seven.
Witness,
RICHARD SKERRETT,
CONRAD CHRISTIAN SEVERIN KNAP. (L.S.)
Clerk to George Shaw,
Birmingham.