Improvements in Steam Boiler and other Furnaces.
Year: 1891

page_text: Date of Application, 20th Mar., 1891
Complete Specification Left, 18th Dec., 1891-Accepted, 23rd Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in Steam Boiler and other Furnaces.
I, SAMUEL OATES, of 45 Kearsley Road, Sheffield in the County of York,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to an apparatus for automatically regulating the admission
of supplementary quantities of atmospheric air to boiler and other furnaces, both in
front and rear of the fire grates, simultaneously or otherwise, for the purpose of
supplying the necessary oxygen to the incombustible gases whilst they are being
rapidly evolved from the fuel on the fire grates, thereby converting them into a
combustible compound, and subsequent smokeless flame.
It is a well known fact that with some kinds of bituminous coal and small slack,
there are short periods of time when it is impossible to pass a sufficient quantity
of oxygen through the grate bars of hand fired boilers to convert all the evolving
gases into a combustible compound, especially when fresh fuel has been added to the
fires, or when they have just been broken up with the rake or poker; consequently
a vast quantity of the gases, at these times, passes off into the flues and chimney's
unconsumed.
There are many methods in existence for admitting supplementary air to the
evolving gases, both in front and rear of the fire grates for the above purpose, but
they are mostly more or less non-effective, inasmuch as they do not admit a
sufficient quantity of air at the proper time or they admit too much, and when it is
not required, thus either allowing some of the gases to pass off unconsumed, or
allowing a surplus quantity of air to pass into the flues with the products of
combustion, thus cooling them down and neutralizing to some extent the calorific
power thereof.
For controlling the admission of air from the back of the ash pit to behind the
bridge either direct or through a heating chamber I employ a flap valve and govern
the opening and closing of this valve as has before been proposed by a chain
attached to it led over a pulley and attached to a rod which extends to the front of
the ash pit where it is attached to an arm on a horizontal rocking shaft and which
shaft can be turned quickly to open the valve but is impeded from turning quickly
in the opposite direction by reason of an arm upon it being coupled by a link to the
lever of the well known rain and lever cataract or equivalent contrivance.
For controlling the admission of air to the front of the furnace above the fire
bars I employ a valve formed of a flat plate which can slide vertically in a grooved
frame fixed between the furnace front and the fire hole door.
Through the door, openings are formed for the admission of air. When the
air valve is raised above the level of these openings there is a free admission of air
to the front of the furnace but when the valve is lowered the admission of air to the
furnace through these openings is arrested. The area of the openings through the
door can also be regulated at will by a thin plate having corresponding openings
therein made to slide in front of them and fastened in any position by a small
thumb screw.
The air valve I support by chains from arms extending from a horizontal rocking
shaft and this shaft couple to the rocking shaft before mentioned so that when
onc is rocked the other rocks with it.
When it is desired to add fresh fuel on to the fires in the furnaces, the fireman
after opening the fire hole door must before he can have access to the fire raise the
front air valve and to do this he must turn one or other of the rocking shafts by a
lever arm upon it.
When the fireman has added the necessary fuel to the fires in the furnaces, he

page_text: closes the fire hole doors but the air valves remain open although their own weight
tends to close them and they can only close gradually.
The approximate time required to open the air valves will be about one second
and the closing of the same can be regulated from that to five minutes or more if
required, according to the quality of the fuel used.
It will be seen that the front air valves are quite independent of the fire hole
doors, and that the attendant, although he may open the doors, yet he cannot
interfere with the fires in the furnaces until he has opened the front air valves as
they cover the openings through which the fuel is put into the furnaces, and that
when he opens the front air valve he must also simultaneously open the rear air
valves, therefore he is compelled to make provision for the inlet of air into the
"furnaces" and "heating chambers" at the bridge after he has in any way interfered
with the fires and closed the fire hole doors.
Dated this 19th day of March 1891
COMPLETE SPECIFICATION.
Improvements in Steam Boiler and other Furnaces.
I, SAMUEL OATES, of 45 Kearsley Road, Sheffield in the County of York,
Engineer, 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 :-
This invention relates to an apparatus for automatically regulating the admission
of supplementary quantities of atmospheric air to boiler and other furnaces, both
in front and rear of the fire grates, simultaneously or otherwise, for the purpose of
supplying the necessary oxygen to the otherwise incombustible gases whilst they
are being rapidly evolved from the fuel on the fire grates, thereby converting them
into a combustible compound, and subsequently a smokeless flame.
It is a well known fact that with some kinds of bituminous coal and small slack,
there are short periods of time when it is impossible to pass a sufficient quantity of
oxygen through the grate bars of hand fired boilers to convert all the evolving
gases into a combustible compound, especially when fresh fuel has been added to
the fires, or when they have just been broken up with the rake or poker; conse-
quently a vast quantity of the gases, at these times, passes off into the flues and
chimneys unconsumed.
There are many methods in existence for admitting supplementary air to the
evolving gases, both in front and rear of the fire grates for the above purpose, but
they are mostly more or less non-effective, inasmuch as they do not admit a sufficient
quantity of air at the proper time or they admit too much, and when it is not
required, thus either allowing some of the gases to pass off unconsumed, or
allowing a surplus quantity of air to pass into the flues with the products of com-
bustion, thus cooling them down and neutralizing to some extent the calorific power
thereof.
For controlling the admission of air from the back of the ash pit to behind
the bridge either direct or through a heating chamber I employ a flap valve
and govern the opening and closing of this valve, as has before been pro-
posed, by a chain attached to it led over a pulley and attached to a rod which
extends to the front of the ash pit where it is attached to an arm on a
horizontal rocking shaft and which shaft can be turned quickly to open the
valve but is impeded from turning quickly in the opposite direction by reason of an
arm upon it being coupled by a link to the lever of the well known ram and lever
cataract or equivalent contrivance.
For controlling the admission of air to the front of the furnace above the fire
bars employ a valve formed of a flat plate which can slide vertically in a grooved
frame fixed between the furnace front and the fire hole door.

page_text: Through the door, openings are formed for the admission of air. When the air
valve is raised above the level of these openings there is a free admission of air to
the front of the furnace but when the valve is lowered the admission of air to the
furnace through these openings is arrested. The area of the openings through the
door can also be regulated at will by a thin plate having corresponding openings
therein made to slide in front of them and fastened in any position by a small
thumb screw.
The air valve I support by chains from arms extending from a horizontal
rocking shaft and this shaft 1 couple to the rocking shaft before mentioned so that
when one is rocke i the other rocks with it.
When it is desired to add fresh fuel on to the fires in the furnaces, the fireman
after opening the fire hole door must before he can have access to the fire
raise the front air valve and to do this he must turn the rocking shaft by a lever
arm upon it.
When the fireman has added the necessary fuel to the fires in the furnaces, he
closes the fire hole doors but the air valves remain open although their own weight
tends to close them and they can only close gradually.
The approximate time required to open the air valves will be about one second
and the closing of the same can be regulated from that to five minutes or more if
required, according to the quality of the fuel used.
It will be seen that the front air valves are quite independent of the fire hole
doors, and that the attendant, although he may open the doors, yet he cannot
interfere with the fires in the furnaces until he has opened the front air valves as
they cover the openings through which the fuel is put into the furnaces, and that
when he opens the front air valve he must also simultaneously open the rear air
valves, therefore he is compelled to make provision for the inlet of air into the
furnaces and heating chambers at the bridge after he has in any way interfered
with the fires and closed the fire hole doors.
Figure 1 of the annexed drawings is a front elevation and Figure 2 is a
longitudinal section of a steam boiler furnace fitted in accordance with my
invention.
Figure 3 shows a modification of the furnace bridge.
Figure 4 is a section to a larger scale of the cataract which I employ.
a is the shell of the boiler. bare the furnaces. ce are the fire bars. d d are
frames to which the fire doors ee are hinged. The fire doors have holes in
them for the admission of air and sliding covers similarly perforated are fitted by
which the holes may be more or less closed. A thumb screw clamps the cover plate
in place. are plates or dampers which can slide in the frames d. Chains passing
from the plates are attached to quadrants on an axis so that when the axis h
turns the plates are raised or lowered. is an horizontal axis below the fire doors
and arms and on the axes and respectively are connected by a rod k.
Another arm on the axis is connected by the rod with the lever m of the
cataract. is a hand lever on the axis i by which it must be turned to raise the
plates before the fires can be fed. are arms on the axis i connected by rods n
and chains passing over guide pulleys with flaps or valves o
in the bridge.
The bridge as shown in Figure 2 is with the exception of the valve frame, built in
fire bricks and slabs. When the flap o is raised air enters the chamber pin the
bridge through openings in the floor of the chamber and the air issues through a
series of holes at p p to mix with the carbonaceous gases from the fuel. In
Figure 3 the arrangement is similar but the bridge is of cast iron.
In order that the quantity of air passing from the ash pit through the fire bars and
fuel may not be lessened by the opening of the valve o, 1 sometimes provide a steam
pipe in connection with the steam space of the boiler and terminating in a
nozzle at g beneath the fire bars. Upon the steam pipe there is a cock q' and
upon the plug of the cock there is an arm connected by a link with another arm on
the axis A.
By this arrangement I cause steam to be applied to urge the air forward between

page_text: the fire bars at the time when the valve o is open, but as this valve closes the
steam cock is also by degrees closed and it is finally shut when air ceases to be
admitted through the bridge.
In Figure is a cistern containing water; in it is mounted a cylinders with a
suction valves at its lower end. The cylinder at its upper end has a gland s²
through which a plunger can slide. From the lower end of the plunger ta
connecting rod passes to the lever m. The lever m has its fulcrum at 'm' and may
carry a counterpoise m³ to counterbalance partially the plates and other parts of
which the connections have been already explained. When the plunger t is raised
on the opening of the fire doors water enters the cylinder freely by the valves but
it cannot escape the same way. The only outlet from the cylinder is by the
branch which is fitted with a mouth piece into which the cone enters. The
cone it will be seen is on a screw spindle and it can be set down to close the mouth
by turning the hand wheel a' upon the spindle and so made to close more or less
completely the exit by the branch s².
In this way the time occupied in the closing of the air passages at the furnace
front and at the bridge can be extended to any extent desired.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. Apparatus in which the admission of air to the front of the furnace through
holes in the fire door is controlled by a plate or damper sliding vertically between
the furnace front and the fire door which plate is governed in its descent by a
cataract or its equivalent substantially as described.
2. Apparatus in which air is simultaneously admitted at the front of the furnace
and at the bridge under the control at each place of a movable plate damper flap
or like part such plates dampers flaps or the like being both governed by the same
cataract or its equivalent substantially as described.
3. Apparatus for the supply of air to furnaces substantially as described and
illustrated by the annexed drawings.
Dated this 9th day of December 1801