IMPROVEMENTS IN THE GRATES OF STEAM BOILER AND OTHER FURNACES
Year: 1884

page_text: I ISAAC SHIMWELL M°DOUGALL, of Irk "Vale, Chadderton near Manchester in
the County of Lancaster Manufacturing Chemist do hereby declare the nature of
said Invention for "IMPROVEMENTS IN THE GRATES OF STEAM BOILER AND OTHER
FURNACES" to be as follows: -
My Invention has for its object the more perfect combustion of fuel and the
prevention of smoke in Steam boiler and other furnaces and consists in imparting
to the fire bars a peculiar motion hereinafter described whereby they are kept clean,
the air spaces maintained open, and the fuel is moved forward carrying the clinker
or the unburnable part of the fuel into a chamber provided for the purpose and
from which the clinker may be removed at intervals as convenient.
The Invention is applicable to furnaces of Steam Boilers annealing pans, Brewers
Coppers and other furnaces where fuel is consumed.
In carrying out my Invention I support the fire bars on bearers independent of
the cam shaft which gives them motion. The cam shaft is arranged to move the
fire bars in a forward direction and to bring them back to their original position at
different intervals. For this purpose the bars are recessed at the front end to
receive the cam shaft. The back portion of the recesses against which the cam
shaft works for imparting the forward movement to the bars being the same in
each bar so as to cause the whole of the bars to move forward together whilst the
front parts of the said recesses by which the return motion of the bars is obtained
are so arranged that the cam shaft comes in contact with the bars at different
intervals.
With the bars thus arranged to move forward altogether and backwards at
different intervals the fuel is caused to travel forward the clinkers are carried into
the clinker chamber the bars are kept clean and the air spaces are kept open.
The bars may rest upon two or more supports and may be connected in any
suitable manner above the supports for the. convenience of removal for alteration
or repairs.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.,
Agent for the said Isaac Shimwell McDougall.

page_text: I ISAAC SHIMWELL MCDOUGALL of Irk Vale Chadderton near Manchester in
the County of Lancaster Manufacturing Chemist do hereby declare the nature of
said invention for "IMPROVEMENTS IN THE GRATES OF STEAM BOILER AND OTHER
FURNACES "and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
:-
My Invention has for its object to provide efficient means for ensuring the more
perfect combustion of fuel and the prevention of smoke in steam boiler and other
furnaces such for example as those of annealing pans and Brewers Coppers and
consists in an improved arrangement for imparting to the fire bars a peculiar
motion hereinafter described whereby they are kept clean, the air spaces are
maintained open, and the fuel is moved forward carrying the clinker or the
unburnable part of the fuel into a chamber provided for the purpose from which
chamber the said clinker may be removed at intervals as convenient.
In order to obtain the aforesaid motion I support the fire-bars on bearers
independently of the cam shaft which gives them motion, and the cam surfaces on
the said shaft are arranged to move the several bars in a forward direction all
together, but to bring them back to their original position at different times. The
bars are recessed at the front end to receive the cam shaft and the back portion of
the recesses against which the cam surface on the cam shaft bears for imparting
the forward movement to the bars are the same in each bar so as to cause the
whole of the bars to move forward together whilst the front parts of the said
recesses, upon which the cam surface bears to give the return motion of the bars,
are so arranged that the cam surface come in contact with the bars at different
intervals.
With the bars thus arranged to move forward all together and backwards at
different intervals the fuel is caused to travel forward the clinkers are carried into
the clinker chamber the bars are kept clean and the air spaces are kept open.
The bars may rest upon two or more supports and may be connected in any
suitable manner above the supports for the convenience of removal for alteration
or repairs.
In order that my Invention may be thoroughly understood I will more parti-
cularly describe the same with reference to the accompanying drawing whereon
Figure 1 represents a longitudinal section of a portion of a boiler having a furnace
arranged according to my Invention-Figures 2 and 3 are enlarged details of
the fire bars and cam shaft and Figure 4 shews a portion of the cam shaft
separately.
The cam shaft A is made to revolve in the direction shewn by the arrows by any
suitable means such for example as a ratchet wheel a fixed on the shaft A and
operated by a pawl a³ moved by an excentric the rod of which is shewn at a³.
In describing the movement of the bars it will be sufficient to describe the
action of two adjacent bars as the rest may be arranged alternately or otherwise
grouped in a similar manner.

page_text: The back part of the recess in the bar B is longer than that of the adjacent
bar C. and the front part of the recess in the bar C is longer than that of the
bar B-As the cam shaft A revolves the bars are moved, by the projecting portion E
of the cam shaft, all forwards together but are not returned or moved back all
together-The other projecting portion F of the cam shaft prevents the bars returning
all together and holds or locks some of the bars (say alternate bars) whilst the
others are being withdrawn-Figure 2 shews the portion E of the cam shaft in
contact with that portion of the bars B. C which is similar in or common to all the
bars, so that all the bars are moved forward at the same time. After the part E
passes this portion of the bars it comes into contact with the projecting part of the
bars C at the front of the recesses and pushes those bars backwards, while the
projecting part F of the cam shaft bears upon the parts B₁ of the bars B and holds
or retains the said bars in position until the backward movement of the bars C has
been completed-When this is done and immediately the part F has left contact
with the parts B¹ of the bars B thus releasing those bars, the part E of the cam
shaft comes into contact with the front part of the recesses of the bars B and
pushes them back to their original position and thus the motion is continued in
such a way that the bars are moved forward all together or simultaneously and are
moved backwards one after the other or at intervals, and by this means the fuel is
carried forward, the air spaces of the bars kept open, the clinkers and dross carried
into the clinker chamber, and the bars kept clean.
The cam surfaces of the cam shaft can be formed in a continuous line along the
shaft as shewn in figure 4 which is a great convenience in manufacture.
I do not limit myself to the precise details herein before described and illustrated
by the drawings, as the same may be varied without departing from the nature of
my invention.
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. In furnaces the use of a cam shaft with portions E and F for operating
and governing or controlling the operation of fire bars arranged and formed
substantially as hereinbefore described and illustrated in the accompanying
drawings.
Secondly. In furnaces the bars B and C supported upon carriers independently
of the cam shaft the said bars having recesses formed as described and illustrated
through which passes a cam shaft formed as described and illustrated for imparting
movement to the said bars as herein before described.