Improvements in or connected with Boiler Furnaces.
Year: 1895

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c., Act, 1883), as required by
the decision of the Comptroller General of the 25th day of July 1896.
Date of Application, 10th May, 1895
Complete Specification Left, 10th Feb., 1896-Accepted, 14th Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in or connected with Boiler Furnaces.
DAVID BROWN HUTTON of 270 Neville Road, Forest Gate, Essex, Manu-
facturer, do hereby declare the nature of this invention to be as follows:-
This invention is connected with the damping of boiler furnaces to prevent the
nush of cold air when the furnace door is opened for the purpose of firing up
o cleaning fires or otherwise, and it is applicable to all circular furnaces for
Lancashire, Cornish, matine or similar boilers, and for boilers of the locomotive
type.
For this purpose
I combine the furnace door with a damper and intervening
connecting mechanism, in such a way that when the door is opened the dampet 18
brought into a position to lessen the through draft over the furnace budge or at
any other place between the furnace grate, and the flues, shaft chimney or outlet
for the gases and conversely when the door is closed the damper is brought back to
the position in which free draught is again allowed.
The manner of obtaining this may be as follows;-
The furnace door is attached to a shaft suspended in a bracket or boss cast
This shaft is carried
on or fixed to the furnace front, dead plate, oi boiler.
through or along the ash pit underneath the bars, and passos through and works in
a boss or bearing cast on the remicn cular plate supporting the back plate which
cairies the fire brick bridge. On the fai side of this semici cula supporting
or division plate a pinion is keyed on to the aforementioned shaft.
This pinion gears with another which is cast on or attached to a semicircular
damper plate which works loosely on or in a male or female boaring respectively
on the semicircular supporting or division plate or on the back plate proper on
which the fire brick bridge is built. This bearing should preferably be in the
centre of the furnace, and the damper plate with its attached pinion should be
geared with the pinion on the shaft afore mentioned in a position opposite to that
of the furnace door so that when the furnace door is opened by turning it on its
axis (on the shalt to which it is fixed) to open the door the semicircular dampei
plate revolves and rises shutting the orifice over the budge, thus stopping the
passage of cold air to the fines or tubes as the case may be. The semien cular
dainper mentioned is not made a close fit to the flue, a small space o clearance
intervenes between it and the furnace tubo or flue to allow sufficient area of
opening for the limited and gentle passage of the smoke and hot gases so as to
prevent their backward issue through the furnace door when it is open while at
the same time preventing the inrush of a large volume of cold air to impede on the

page_text: flues, tubes, or tube plates of the boiler, and thus prevents the sudden cooling and
contraction causing leakage etc., through the cold a striking on these surfaces.
The door and damper plate being geared in their action opposite each other are
thus balanced, so that in stoking, the door is opened and shut with the minimum
amount of labour to the stoke. Catches or stops may be provided for the
damper and the furnace door. The door may when open act as a damper for the
ash pit
In place of the above construction the door may be hinged in the ordinary
manner, and connected by suitable rods and bell ciauks with a damper or dampers
suspended by trunnions of other convenient bearings and adapted to work, that is
to say, be lifted and lowered through the quadrant of a circle or thereabouts.
For boilers of the locomotive type the furnace door is connected by suitable cranks
and rods with a pivoted damper of the ordinary shape in the smoke box or smoko
stack which damper is operated in the manner described on the opening and
closing of the door.
Dated this 10th day of May 1895.
HERBERT HADDAN & Co.,
Agents to Applicant.
Improvements in or connected with Boiler Furnaces.
I DAVID BROWN HUTTON of 270 Neville Road, Forest Gate in the County of
Essex, 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 is connected with the damping of boiler furnaces to prevent the
urush of cold au when the furnace door is opened for the purpose of firing up
o cleaning fires, or otherwise; and it 18 applicable to all circular furnaces for
Lancashire, Cornish, marine or similar boilers and for boilers of the locomotive
type.
For this purpose combine a pivoted furnace door with a damper and
intervening connecting mechanism, in such a way that when the door is opened the
damper 18 brought into a position to lessen the through draught over the furnace
bridge or at any other place between the furnace grate and the flues, shaft
chimney or outlet for the gases, and conversely when the door is closed the
damper is brought back to the position in which free draught is again allowed.
The manner of obtaining this is as follows.
The furnace door is attached to a shaft suspended in a bracket or boss cast on
or fixed to the Tminace front, dead-plate, or boiler. This shaft is carried through
or along the ash pit underneath the bars and passes through and works in a boss or
bearing cast on the semi-cu cular plate support.ng the back plate which carries the
fie-brick budge. On the far side of this semicircula supporting or division plate
a pinion is keyed on to the aforementioned shaft. This pinion gears with another
which is cast on or attached to a semien cula damper plate which works loosely
on or in a male or female beating re-pectively on the semicircular supporting or
division plate or the back plate proper on which the fire buck bridge is built.
This bearing should preferably be in the centre of the furnace and the dumper
plate with its attached pinion should be geared with the pinion on the shalt afore-
mentioned in a position opposite to that of the furnace door so that when the
furnace door is opened by turning it on its axis (on the shaft to which it is fixed)
to open the door, the semicircular damper plate revolves and rises. shutting the
orifice over the bridge, thus stopping the passage of cold air to the Hues or tubes
as the case may be. The semicircular damper mentioned is not made a close hit to

page_text: the flue, a small space or clearance intervenes between it and the furnace tube or
flue to allow sufficient area of opening for the limited and gentle passage of the
smoke and hot gases so as to prevent their backward issue through the furnaco
door when it is open, while at the same time preventing the inrush of a large
volume of cold air to impinge on the flues, tubes or tube plates of the boiler, and
thus prevents the sudden cooling and contraction causing leakage &c. through the
cold air striking on these surfaces. The door and damper plate being geared in
their action opposite each other are thus balanced so that in stoking the door is
opened and shut with the minimum amount of labour to the stoker. Catches and
stops may be provided for the damper and the furnace door. The door may when
open act as a damper for the ash pit
For boilers of the locomotive type the furnace door is connected by suitable
cranks and rods with a pavoted damper of the ordinary shape in the smoke box or
smoke stack which damper is operated in the manner described on the opening and
closing of the door.
The accompanying drawings illustrate this invention as applied to boiler furnaces
and sinoke boxes.
Fig. 1 is a longitudinal section of part of a double ended marine boiler. Fig 2
18 an end view thereof. Fig. 3 18 a longitudinal section and Fig. 4 an end
elevation, partly broken away, of part of a marine boiler with its smoke box.
Fig. 5 is a plan view of part of Fig. 4.
Referring to Figs. 1 and 2 a represents the furnace tube, b the giate, c the
budge, d the firing opening, e the ash pit, is the shaft extending under the grate
and adapted to evolve in bearings f g 18 the furnace door fixed on the front
end of shaft; h is a toothed wheel on the rear end of said shaft, this toothed
wheel gearing with the toothed wheel ' fixed to or formed in one with the dampor
plate, and adapted to revolve on pin k. Fig. 1 shows on the left the door open
and damper closed and on the right the damper open and door closed. 1, Fig. 2
represents a stop against which the door abuts when closed
The same letters refer to the same parts in Figs. 3 to 5; here however the
door g revolves on pin f' and carries eccentrically of said pin a pin in to which 18
attached the rod n, the other end of which is attached to the boll-ciauk lever o,
pivoted at p and connected by od 9 to the damper pivoted at a and counter-
weighted at t.
Fig. 4 shows on the loft the door open and the damper closed; on the right the
damper open and the door closed.
is the stop for the door in its closed position, l' the stop for the door in its open
position To permit the door to swing on its pivot without hindrance from the
inner plate u of said door, the flange u around the furnace mouth d is cut away
at w and the door g entries at a projecting flange fitting to the flange at the
space to in order to complete the flange v wlien the door is closed.
Other forms of boilet furnaces are fitted in the same manner as the marine
boilers illustrated in the drawings.
Having now particularly described and ascertained the untune of this inveu-
tion and in what manner the same is to be performed I would state that I am
aware that it has been previously proposed by means of the fire-doors to
automatically operate dampers in the fines for the purpose of preventing the Lush
of cold air on the opening of the no doors, but I lay no general claim to Buch
constructions, and I declare that what I claim is -
In a boiler furnace,
1. The combination with a damper of a furnace door g, adapted to revolve in
its plane and to revolvo a shaft geared to sand damper in such a manner that the
door and damper are substantially balanced in weight or moment and are
adapted to be operated for the purpose set forth
2. The combination of door g, shaft, gear wheels h, h' and damper / constructed
to operate as described.

page_text: 3. The combination with a damper r in the smoke box or flue, of a furnace
door g pivoted on stud to revolve in its plane and connected by lever gear
with said damper to co-operate therewith in the manner and for the purpose
specified.
4. The combination with damper pivoted as and counterweighted at t,
of door g pivoted at f' and rods n, g and lever o for connecting said door and
damper for the purpose set forth.
Dated this 10th day of February 1896.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.C., Agents to the Applicant.