Regulating the Supply of Air to Furnaces.
Year: 1887

page_text: Date of Application, 23rd Apr., 1887
Complete Left, 23rd Jan., 1888
Complete Accepted, 24th Feb., 1888
and Regulating the Supply of Air to Furnaces.
We, JOSEPH KNOWLES BROADBENT of Hope Street Salford in the County of
I.ancaster Mechanical Engineer and ARNOLD BUDENBERG of Southgate Manchester
in the County of Lancaster Engineer do hereby declare the nature of this invention to
be as follows:-
--
This Invention relates to the system of and apparatus for preventing smoke and
regulating the supply of air to furnaces now well known as Broadbent's, and for which
Letters Patent were granted No. 19, dated the 3rd day of January A.D. 1867.
For some years past instead of regulating the air supply by means of a valve below
the bridge the same purpose has been effected by means of a louvre valve in the
furnace door and this valve has been actuated by the opening of the door and by a
"meter" in a manner and by means analogous to those described in the Specification
to the aforesaid Letters Patent, the motion between the door and the meter and
between the meter and the louvre being transmitted by a chain.
These improvements consist in substituting for the second bridge and the baffle arch
in the flue of the boiler a metallic U shaped ring; in an improvel construction of the
chain; in an improved construction of the louvres and in a simplified and improved
form and construction of the escapement of the meter.
The Ushaped ring forms a part of the boiler flue and it is arranged with its
convexity towards the water space, in the plane of the bridge, so as to form a contracted
way at the bridge and more effectually premote the combination of the oxygen of the
air with the hydrogen and carbon monoxide from the fuel in the furnace.
The chain which connects the meter with the louvre valve in the furnace door has a
few of its links removed and a spiral spring substituted therefor. This arrangement
prevents damage to the meter in the rather common event of the boiler attendant
pulling the chain to hasten the closing of the louvre, and it further enables the meter
to be placed within a wider range of position relatively to the furnace door.
The louvre valve is provided with side projections through which pass the pins or
pivots upon which the louvres turn; lugs or projections are cast upon the middle of

page_text: the louvre plate and fit within a channel in the weight which is secured thereto by
pins passing through the weight and the lugs. By this construction a broken louvre
is enabled to be replaced in a few minutes without trouble and without skilled
assistance.
In the meter a peculiarly constructed lever escapement is employed in place of the
verge escapement hitherto used. The lever is provided with two pins which alternately
engage with the scape wheel and at the opposite end with a toothed quadrant which
gears with a pinion on the balance wheel arbor. The escapement so constructed is
more accurate, and certain and is of simpler construction than that hitherto employed.
Dated this 21st day of April A.D. 1887.
WILLIAM E. HEYS,
Agent for the Applicants.
and Regulating the Supply of Air to Furnaces.
We JOSEPH KNOWLES BROADBENT of Hope Street Salford in the County of
Lancaster Mechanical Engineer and ARNOLD BUDENBERG of Southgate Manchester
in the County of Lancaster 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 the System of and Apparatus for preventing smoke and
regulating the supply of air to furnaces now well known as Broadbent's, and for which
Letters Patent were granted No. 19 dated the 3rd day of January A.D. 1867.
For some years past instead of regulating the air supply by means of a valve below
the bridge the same purpose has been effected by means of a louvre valve in the furnace
door and this valve has been actuated by the opening of the door and by a meter
in a manner and by means analogous to those described in the Specification to the
aforesaid Letters Patent, the motion between the door and the meter and between the
meter and the louvre being transmitted by a chain.
These Improvements consist in substituting for the second bridge and the battle arch
in the flue of the boiler a metallic U shaped ring; in an improved construction of the
chain; in an improved construction of the louvres and in a simplified and improved
form and construction of the escapement of the meter.
The shaped ring forms a part of the boiler flue and it is arranged with its
concavity towards the water space, in the plane of the bridge, so as to form a contracted

page_text: way at the bridge and more effectually promote the combination of the oxygen of the
air with the hydrogen and carbon monoxide from the fuel in the furnace.
The chain which connects the meter with the louvre valve in the furnace door has
a few of its links removed and a spiral spring substituted therefor. This arrangement
provents damage to the meter in the rather common event of the hoiler attendant
pulling the chain to hasten the closing of the louvre, and it further enables the meter
to be placed within a wider range of position relatively to the furnace door.
The louvre valve is provided with side projections through which pass the pins or
pivots upon which the louvres turn; lugs or projections are cast upon the middle of
the louvre plate and fit within a channel in the weight which is secured thereto by
pins passing through the weight and the lugs. By this construction a broken lonvro
is enabled to be replaced in a few minutes without trouble and without skilled
assistance.
In the meter a peculiarly constructed lever escapement is employed in place of the
verge escapement hitherto used. The lever is provided with two pins which alternately
engage with the scape wheel and at the opposite end with a toothed quadrant which
gears with a pinion on the balance wheel arbor. The escapement so constructed is
more accurate and certain and is of simpler construction than that hitherto employed.
And in order that this our said Invention may be more clearly understood we have
hereunto appended a sheet of drawings to which reference is hereinafter made, similar
letters being used to indicate similar parts in the different drawings.
Fig. 1. is an elevation of the front end of a boiler with our improvements applied
thereto; Fig. 2 is a longitudinal section of the boiler through one of the flues showing
the arrangement and application of the U shaped ring; Fig. 3 shews more fully one
of the meters, the louvre valves, and the connecting chain; Fig. 4 is a side view of
the apparatus shewn in Fig. 3. the louvre valve however being shewn in section, and
Fig. 5 illustrates in detail our improved escapement and the train of wheels employed
in the meter.
A (Figs. 1 and 2) is part of a Lancashire boiler provided with louvre valves B B'
in the furnace door and meters C C₁ each meter being connected to the weight of one
of the louvre valve by means of a chain D or D'. E (Fig. 2) is one of the flues of the
boiler; F is the U shaped ring the object of which is to contract the opening above
the fire bridge G and to promote by deflection, a more intimate combination of the
carbon monoxide with the air admitted by the valve B. In the arrangement shewn
the ring is part of the flue and is formed by corrugating one of the plates of which the
flue is formed.
Referring to Figs. 3 and 4, H is the furnace door and B C D as before are
respectively the louvre valve, meter, and connecting chain. The louvres B are pinned
or pivoted to the side plates R R which are cast upon the furnace door. The pins or
pivots are passed from the outsides of the side plates into the louvres at or a little
above their centres. Each louvre is furnished near the centre with a lug or projection S
which enters and is pivoted within the channel shaped weight W as shown in Fig. 4.
Thus, as the weight W is raised the louvres are turned on their pivots into an angular
position and the valve is consequently opened for the admission of air. The valve
closes automatically by the descent of the weight W.
J is the lever for operating the meter C; it carries on one end the counterweight K,
and at the other end it is connected to the weight W by means of the chain D. The
lever is mounted on the shaft of the wheel T and drives the train of wheel as described
in the herein before mentioned. Specification. By means of a ratchet and pawl or
similar device the wheel T is revolved and drives the train of wheels as the chain end
of the lever J is depressed. Upon the lever being released the action of the counter-
weight K returns it to its normal position without moving the wheels, since the pawl
slips over the teeth of the ratchet.
The operation of the apparatus is as follows:-The furnace door is swung back for
firing purposes, and, the distance between the points where the chain is connected
respectively to the weight W and to the lever J being lessened, the counterweight K
raises the chain end of the lover to its highest position. The fuel having been supplied

page_text: to the furnace, the door is sbut. The weight W is now raised owing to the change in
the position of the lever J, and the louvres B are open. The weight W operates the
train of wheels in the meter through the chain D and the lever J gradually falls and
closes the louvre valve. By this means the amount of air admitted to the furnace is
varied a large volume being admitted when needed to ignite the charge of fresh coal,
while the volume is diminished as combustion increases.
M is a spring inserted in the chain D so as to allow the position of the meter to be
varied and to reduce the risk of damage to the meter in the event of the fireman
pulling the chain to hasten the closing of the valve. The speed at which the valve
closes may be varied by moving the clamp L along the lover J.
Details of our improved lever escapement are shewn in Fig. 5. Instead of the
usual pallet, one end of the lever carries two pins N N which engage alternately with
the teeth of the escape wheel O. The other end of the lever is provided with a
quadrant. U gearing with a pinion V mounted on the axis of the balance wheel.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what
wo claim is —
(1.) In a furnace or flue, the combination and arrangement of a U shaped ring or
corrugation with the fire bridge; substantially as described and illustrated and for the
purposes set forth.
(2.) The combination with the connecting and operating chain, of a spring M;
substantially as and for the purposes hereinbefore set forth.
(3.) In a louvre valve for adimitting air to furnaces the construction and arrange-
ment of the louvre plates and sliding weight; substantially as hereinbefore described
and as illustrated by the accompanying drawings.
(4.) In a meter for controlling the admission of air to furnaces; an escape move-
ment constructel and operating substantially as set forth and illustrated by the
accompanying drawings.
Dated this 90th day of January AD 1888
WILLIAM E. HEYS,
Agent for the Applicants.