Improvements in Apparatus for Controlling the Supply of Air to Puddling and other Furnaces.
Year: 1892

page_text: Date of Application, 26th Apr., 1892
Complete Specification Left, 25th Jan., 1893-Accepted, 25th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Controlling the Supply of Air to
Puddling 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 :-
In the Specification of a former Patent granted to me No. 5018 in the year 1891
I described apparatus for controlling the supply of air to the front and rear of the
fire grates of furnaces. The apparatus consisted of an air valve or damper which
was necessarily raised whenever fresh fuel was fed on to the fire and was closed
gradually-the closing being controlled by well known cataract arrangements
which also controlled the opening or closing of a tap or valve for allowing steam to
pass from the boiler through steam jets into the ash pit below the fire bars thus
creating an increased or forced draught.
I now as before place between the furnace front and the fire door a sliding plate
or damper which has to be raised before fuel can be put on to the fire and I couple
such plate to a lever the movements of which are controlled by a cataract
arrangement which allows the plate or damper to be raised freely but controls its
descent so that it can only descend gradually and according to my present invention
I provide for admitting air to the fire door end of the furnace and to the chimney
end through two pipes or channels which are led preferably over the top of the
furnace from the furnace ends. Each channel near its end is fitted with a slide or
damper by which the admission of air to the passage can be controlled-one of
these slides is hung from one arm of the cataract lever and the other from the
other arm-the cataract cylinder being situated above the furnace top. One arm
of the lever is also coupled to an arm by which the opening or closing of a valve on
a steam pipe is controlled. The steam pipe past this valve is branched and one
branch led into the open end of one air channel and the other branch into the other
air channel. On each of these branches is also a hand tap or valve by which the
passage of steam through it can be separately controlled.
The air passage which passes to the fire door end of the furnace I make to open
into a horizontal box fixed outside and along this end of the furnace-and I form
a horizontal row of slits from this box into the interior of the furnace at a distance
above the fire bars. The air passage which leads to the chimney end of the furnace
I make to open into the lower part of the chimney beyond the reverberatory or
neck bridge.
In this way whenever the plate or damper which is between the furnace front
and fire door is raised for fuel to be fed on to the fire the dampers for admitting air
to the two air channels are both opened and at the same time a jet of steam is made
to issue into each channel to produce a forced blast or stream of air through it.
Dated this 26th day of April 1892.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Controlling the Supply of Air to
Puddling 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 :-
It is well known that when a fresh supply of fuel has been put onto the fire

page_text: grate of a re-heating, puddling, annealing and such like furnaces, extremely dense
volumes of black smoke and unburnt gases are caused to issue from the chimney in
connection with the furnace in consequence of the oxygen in the air which has
passed through the grate bars not having been sufficient in quantity to satisfy the
demands of the evolving gases. It is therefore expedient to furnish an auxiliary or
supplementary supply of air in order that the evolved gases may receive a sufficient.
quantity to make a combustible mixture; but as this supplementary supply is only
required for a short time after firing, or when the fire has been broken up with the
rake, it is also expedient to prevent undue cooling of the furnace and the flues that
the supplementary supply should be shut off when not required.
To accomplish these ends I cause a current of atmospheric air induced by a
steam jet to pass by a pipe into the firing chamber of such furnaces above the fire
bars, and also by like means another current when necessary to pass into the
"uptake or "downtake as the case may be, and I regulate the quantity and
duration of such currents by means of a damper or dampers governed by a
"cataract," or its equivalent.
"
"
In order that my invention will be better understood, I illustrate the same as
adapted to a re-heating furnace, such as commonly used in forges and rolling mills
for reheating piles of iron and ingots of steel in which the products of combustion
after traversing through the body or heating chamber pass forward over a
reverberatory, or neck bridge, thence into an uptake or chimney which is connected
to the inner tube or flue of a boiler in which steam is generated by the waste beat
from the escaping products of combustion.
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 14 show a front or side elevation of a reheating furnace, with my
apparatus applied thereto.
Figure 2 is an end elevation of the same, showing the ash-pit end of the furnace
and a side view of my apparatus.
Figures 3 and 3 show a plan of the furnace roof covering the firing and heating
chambers, they also show a part plan of my apparatus the levers having been
removed in order to more clearly show the air and steam pipes and the valves
connected therewith.
A is a plate or damper which (as is described in my former Specification No. 5018
in the year 1891) slides vertically between the firehole door and the furnace front
plate, in a frame A¹.
B is a lever poised on the fulcrum B'; the handle end of this lever, which in
Figure 2 is broken away, must be pulled down by the fireman to enable him to
raise the sliding damper A before he can add fresh fuel to the fire, or in anyway
interfere with it. B2 is a stop bar fastened on to the fulcrum arm B³ to adjust the
distance the forearm of the lever B should be pulled down.
C is a link that connects the rear arm of the lever B to the forearm of the
lever D, this lever D being poised on a fulcrum D'. From the forearm of this
lever is suspended a damper or valve E, that slides vertically in a valve case E'
and regulates the flow of air through the pipes E³, to this forearm is also attached
a rod F, which is connected to a piston that works in the cataract cylinder G. To
the reararm of this lever D is suspended another damper plate H which also slides
vertically in a valve case H₁ and regulates the flow of air through the pipes H*.
To this reararm is also attached a rod I, the lower end of which is connected to an
arm 11, that is secured to the spindle of the steam turn valve or tap J, this valve
being fixed in a line of steam pipes J¹. The steam pipe conveys the steam from its
source of supply into branch pipes J and J' and thence to the nozzles J and J'
for the purpose of inducing currents of air into the pipes E' and H². In these
branches are fixed taps or valves J and J' to enable the flow of steam to be
separately controlled to each nozzle.
The pipes E and H form the passages or channels for conveying the induced
currents of air into the uptake K beyond the reverberatory bridge and into the

page_text: horizontal box L fixed at the firing end of the furnace, thence into the firing
chamber above the grate respectively. Instead of arranging the air channels
over the roof of the furnace I can fix them otherwise but I prefer for simplicity to
fix them as I have shown them over the top of the furnace.
Figures 4 and 5 show in detail one form of "cataract" I employ.
Figure 4 is a part sectional elevation and Figure 5 is a part sectional plan.
G is a cylinder that oscillates on trunnions to allow the vertical motion of the
piston rod F to accommodate itself to the vibratory motion of the lever D, without
the intervention of vibrating links. When the piston rod F is lifted by means
of its connection with the lever D, it causes the nut or collar F' to rise and bear
against the underside of the piston block F and make it also rise in the cylinder
thus displacing the water, oil or other liquid which is above it by allowing it to
flow rapidly underneath the valve Fs and through a series of holes drilled in the
piston block. When the piston is allowed to descend the valve F³ attached to the
piston rod first falls on the piston block and covers the holes therein, consequently
the liquid must pass from the underside of the piston to the topside by flowing
through the pipe G' in which a tap is fixed. The size of the orifice in the plug of
this tap is increased or diminished as required to regulate and control the flow of
the liquid from the bottom to the top of the piston, thus regulating the time of its
descent and consequently the time in which the sliding damper A and the air and
steam valves E Hand J shall descend or close.
M M are arms which carry the trunnions on which the cylinder G oscillates;
they are bolted to a bracket N that is secured to a foundation plate O, (Figures 2
and 3,) such plate being securely fastened to an angle bar or other frame P that is
connected to the side plates which form the outer casing of the furnace.
It will now be easily seen that when the fireman wishes to add fresh fuel to the
fire or in any way interfere with it he must first pull down the forearm of the
lever B, thus actuating the lever D and by means of its connection with the air and
steam valves E H and J provision is made for a supplementary quantity of air to
pass into the "firing chamber of the furnace and into the "uptake" for the
purpose of converting the incombustible gases into combustible compounds.
Although I have described the method of automatically controlling the admission
of air to the front and rear of furnaces only it must be understood that I can in a
similar manner admit air to the " heating chamber" or any other part of the
furnace as may be 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 firing or heating chambers of
puddling, reheating and other furnaces, or to the uptake or downtake is controlled
by a valve or damper sliding in a frame, such frame being fixed in a pipe or other
channel through which air is urged by a steam jet; the closing of such valve or
damper being governed by a cataract or its equivalent.
2. Apparatus for controlling the admission of air to puddling, reheating,
annealing and other furnaces, substantially as described and illustrated by the
annexed drawings.
SAML. OATES.