IM- PROVEMENTS IN REGULATING THE PROPORTIONAL DRAUGHT IN FURNACES OF STEAM GENERATORS BY THE AUTOMATIC AND COMBINED ACTION OF THE DAMPERS AND FURNACE DOORS
Year: 1876

page_text: LETTERS PATENT to Désiré Liévin Dernoncourt, Merchant, of Saint Denis, in
the Department of Seine, in the Republic of France, for the Invention of "IM-
PROVEMENTS IN REGULATING THE PROPORTIONAL DRAUGHT IN FURNACES OF
STEAM GENERATORS BY THE AUTOMATIC AND COMBINED ACTION OF THE
DAMPERS AND FURNACE DOORS."
Sealed the 1st December 1876, and dated the 5th June 1876.
PROVISIONAL SPECIFICATION left by the said Désiró Liévin Dernoncourt at
the Office of the Commissioners of Patents on the 5th June 1876.
DÉSIRÉ LIEVIN DERNONCOURT, Merchant, of Saint Denis, in the Department of
Seine, in the Republic of France. "IMPROVEMENTS IN REGULATING THE PRO-
PORTIONAL DRAUGHT IN FURNACES OF STEAM GENERATORS BY THE AUTOMATIC
AND COMBINED ACTION OF THE DAMPERS AND FURNACE DOORS."
It is a well known fact that a great loss of heat is occasioned by the want of a
continuous and proper regulation of the draught, the principal causes in the loss are
the opening of the furnace doors to feed the fire or clear the grate, whilst the intro-
duction of fresh coal effects the liberation of large quantities of inflammable gases
which by the excess of draught from the open doors are driven up the chimney
accompanied with a large proportion of heat which is a complete loss.
These drawbacks are remedied by a combined and automatic regulation of the
furnace doors and dampers by causing them to operate simultaneously and conjointly
in the following manner:-In lieu of the ordinary furnace doors I employ two
doors sliding in a slide fixed in front of the mouth of the furnace, these doors run
on rollers placed so as to allow the doors to close flush with the furnace opening.
One of these doors is larger than the other and is connected by a shaft to a pulley
worked by hand and connected by a chain with the damper; rings are placed on
the chain for shortening or lengthening it for regulating the level of the damper accord-
ing to the coal employed.
The doors are connected by a hook which fastens them automatically when they
are closed. In opening the furnace mouth and causing the descent of the damper to
the level chosen for a normal action of the furnace it suffices to detach the hook
uniting the two doors, when that one connected to the shaft and chain is drawn
along by the weight of the damper.
The rotation of the pulley is regulated by movable stops fixed in the masonry
which are drawn out to arrest the pulley and pushed in for causing the complete
descent of the damper.
The doors are closed by a half or third of a revolution of the pulley.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Désiré Liévin Dernoncourt in the Great Seal Patent Office on the
1st December 1876.
DÉSIRÉ LIEVIN DERNONCOURT, Merchant, of Saint Denis, in the Department of Seine,
in the Republic of France. IMPROVEMENTS IN REGULATING THE PROPORTIONAL
DRAUGHT IN FURNACES OF STEAM GENERATORS BY THE AUTOMATIC AND COMBINED
ACTION OF THE DAMPERS AND FURNACE DOORS."
It is a well known fact that a great loss of heat is occasioned by the want of a
continuous and proper regulation of the draught, the principal causes in the loss are
the opening of the furnace doors to feed the fire or clear the grate, whilst the intro-
duction of fresh coal effects the liberation of large quantities of inflammable gases
which by the excess of draught from the open doors are driven up the chimney
accompanied with a large proportion of heat which is a complete loss.
These drawbacks are remedied by a combined and automatic regulation of the
furnace doors and dampers by causing them to operate simultaneously and con-
jointly without requiring the displacement of the furnace entrance, for it is practi-
cally known that to utilize the combustible to the maximum, whatever its nature, it
is indispensable that the doors should be either opened or closed to relatively and
continuously adjust the draught of the flues with the excessively variable phases
of the progress of the furnace."
The main object of this Invention is to supply the stoker with the simplest and
safest means to render the damper subservient at all times or to regulate the
draught with the burning of the furnace; not only should this relation between the
two exist in a permanent manner but I have so contrived as to render it indepen-
dent of the will of the stoker by making it self-acting so that once regulated it sub-
sists and supports itself.
One of the best solutions of this principle consists in mounting the doors so that
they can slide in front of the furnace, and at the same time utilizing this movement
to regulate the damper of the flue or chimney whilst the entrance to the furnace is
not interfered with by this displacement and without changing the stoker's work
when the hearth is cleaned or presenting any obstacle to the exit of the cinders and
dross, the mechanism being most simple and exempt from deterioration, not requir
ing any sustained attention of the fireman, leaving his customary habits and usual
routine unaltered, these are the principal considerations which have guided me in
realizing my Invention, which I will now explain by reference to the accompanying
Drawings which represent my system of automatic register applied to a mixed
generator consisting of three boilers the upper one being tubular for the return of
the flame.
Fig. 1 is a side view of the generator partly in section in the rear to show the
damper and chinney; Fig. 2 is a front elevation; Fig. 3 a vertical section of tho
plate of the furnace following the line 1-2; Fig. 4 is a horizontal section at 3-4
of the plate and of the doors of the furnace. The plate of the stove a is of cast iron
with a projection b existing throughout its breadth and serving as rail or slide to
the doors c and d of the furnace. This rail b may be joined to the iron or cast-
iron plate provided that it will satisfy the results hereafter mentioned.
The rail is a little below the entrance to the furnace and presents an inclined plane
reaching from outside to inside to the course of the rollers c of each of the doors c and
d; parallel, but in an inverse sense, these rollers have their rolling surface inclined
so that by the simple action of weight the doors are naturally and constantly applied
to the flat surface surrounding the furnace mouth; with respect to this entrance
the rail is isolated from the plate a of the furnace thus leaving a space b', which
is indispensable for the exit of the slag and dross, which without this space or open-
ing would collect between the rail b and the plate a and would prevent the
rollers running. The rollers e are kept on the rail, first, by their conical form aud
the inclination of the rail, secondly, by a check inside which serves as guide to them
whilst leaving a small interval between the inside of the rail to facilitate motion.

page_text: The doors c and d may be any shape, but it is essential that their lengths should
differ; in height they excede that of the furnace mouth to join in this manner, in
length the left one c is less broad by some centimetres than the entrance f, so that
the fireman cannot make exclusive use of it and put the apparatus on one side so
that no advantage would be gained over the actual or present method.
The second door d in its normal position should alone form the enclosure of the
furnace, the door c to the left is invariably held in that position by the latch or
hook turning on the plate a, another hook also with handle serves to connect
the two doors together. The door d is longer than the furnace opening, it is also
made to cover the edge of the door c a few centimetres so that when the two doors
are hooked together and that it is desired to work the register without opening
the furnace whilst sliding on the rail, no fissure or opening is left that can admit air.
The door d is connected by a shaft i to a lever j fixed to a pulley K which
turns loose on an axis fixed to the furnace plate a. The lever j terminates in a
handle m, and between the pulley and the connection of the shaft this lever rests on
the stop knob p, which can be moved in the groove of the plate a. Divisions
marked on this plate at a show by Figures the heights of the damper corresponding
with the positions of the stop knob p. The pulley K is grooved and draws with it a
chain n, which by guide pulleys 8, 8, is attached at the other end to the damper.
A counterweight t balances the weight of the damper, less two or three kilo-
grammes necessary for governing the movement of the doors. All that is required
of the fireman in working the damper or the mechanism is to overcome the resis-
tance of these few kilogrammes.
Below the counterweight the chain is formed of graduated rings separated
about 5 centimetres apart, and which serve to lengthen or shorten the chain accord-
ing to the opening the damper should give to be always in accord with the com-
bustible burnt. The chain from the pulley is connected by a hook to one or other
of the rings and a padlock invariably fixes the hook and ring. By this means when
the normal burning of the furnace is established and that it is observed that the
smoke of the flame at the time of charging does not escape at the furnace mouth
there is no necessity to occupy one's self with the damper further than for its
general working.
The diameter of the pulley K. is sufficient for the displacement of the door d,
when it entirely clears the entrance to the furnace to be effected by the cord of an
arc smaller than the half circumference and to avoid the dead points in the course
of the shaft.
Action of the Register.-Supposing the damper regulated in accordance with the
possible displacement of the doors, the chain hooked and padlocked as described.
In charging with coal the stoker raises the hook to liberate the door d and
clear the entrance to the furnace. The damper arrives at the bottom of its course,
that is to say, at the level selected for the burning of the furnace with the least
draught. By this minimum draught the drawing in of air into the furnace is
avoided and consequently the unburnt gases are not drawn with it. After the
charge the stoker immediately leads the door d to its primitive position, and when
resting against the head of the latch his hooked with the door c, the damper is
then wide open. The fresh coal produces a quantity of gas which it is urgent to
burn in the furnace itself for the draught re-established it follows the current and
pruduces a smoke rich in combustion, to force this gas to remain in the furnace and
here to burn itself the stoker unhooks the door c, and with the handle m he moves
the two doors from left to right, always keeping the furnace closed, and stops the
apparatus in the position proved by experience, or in other words he proportions
the draught to the combustion, the coal being ignited the two doors are led back
again by the handle m, and the door c fastens to its latch g, the damper is then at
the height of its course.
It has been remarked that by the disposition of the rail ba space b'is left between it
and the plate a, this space allows the refuse and dross to fall through and which the
stoker removes at cach stiring or clearing the fire; without this space the rollers

page_text: would not easily run, with the same object in view the rail may be placed above
the entrance of the furnace and the doors suspended therefrom by their rollers, this
combination would be subordinate to the local dispositions and would necessitate
modifications in the governing mechanism of little importance which rather
concerne the arrangement of the principal organs than the organs themselves.
The shaft which actuates the doors can also be replaced by a chain or the
lengthening of the chain of the damper, in adding to the opposite side an arrange-
ment of counterweight chain to return the doors when closed.
I also reserve the direct application of the chain pulley K by reversing its order
at the furnace entrance in replacing the right door preserving only the left one
fashioned for accommodating itself to the pulley. The movement also of the doors
in a vertical manner instead of horizontal and utilizing this backward and forward
motion for regulating the damper. And the use of a rack solid with the large door
governed by a toothed wheel turned with the grooved pulley K for sliding one or
both doors.
I claim as my Invention the automatic register as herein described and represented
by the Drawings and its application to all kinds of steam generators of furnaces of
any description burning coal, coke, charcoal, or combustibles of any description.
I consider the basis of my rights to rest especially-
1st. In the disposition of the inclined rail with a space corresponding with the
furnace entrance for the liberation of refuse.
2. The arrangement of the rail and rolling doors for keeping the doors con-
stantly applied to the facade of the furnace without guides of any sort.
3. The optional solidity of the doors so as to act conjointly or independently.
4. The government of the doors by a shaft articulated at one end to a lever
fixed to the grooved pulley K of the register.
5. The moveable bolt in the circular groove of the furnace plate and serving as
stop to the mechanism in any desired position shown by figures marked at the side.
6. The graduated ring regulator of the height of the register.
7. The padlock which renders the action of the register invariable when once
fixed.
8. The counterweight balancing the weight of the register.
9. The disposition of the rail or sliding way of the rollers above the entrance
of the furnace holding the doors suspended.
10. The government of the doors by the chain of the register aided by the
counterweight to produce their inverse displacement.
11. The replacing of the governing door by the pulley K.
12. The arrangement of the doors to work vertically.
13. The use of racks and gear work to produce the sliding of the doors. The
whole independent of the form, material of construction, and dimensions of the
organs for conducing to the complete utilizing of the heat, with an economy in fuel
and in a regular working in steam generating apparatus, and generally in the pro-
duction of heat no matter how they are ultimately employed.
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