IMPROVEMENTS IN APPARATUS FOR CONSUMING SMOKE IN FURNACES
Year: 1883

page_text: 2
LETTERS PATENT to John Henry Johnson of 47 Lincolns Inn Fields, in the
County of Middlesex, Gentleman for an Invention of "IMPROVEMENTS IN
APPARATUS FOR CONSUMING SMOKE IN FURNACES" communicated to him
from La Compagnie du Chauffage industriel resident at Paris in the Republic
of France.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 12th February 1883.
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN APPARATUS FOB CONSUMING SMOKE IN FURNACES"
a communication to me from La Compagnie du Chauffage industriel resident
at Paris in the Republic of France
}
This Invention relates to; means or apparatus for effecting the consumption of
Smoke in furnaces by avoiding the admission of an excess of air and automatically
regulating the volume introduced underneath the bars and also in some cases by
employing a steam jet automatically brought into action at certain times for a
limited period as hereinafter described.
In carrying out this Invention as applied to furnaces working with a blast air
from a blower mixed with a certain quantity of burnt gases is delivered under the
Grate in the usual manner and during the normal working of the furnace the
proper action is ensured by regulating the quantity of air admitted and by the
introduction of a mixture of air and burnt gases and also by moving the damper in
the chimney When Stoking or clearing the furnace however it becomes necessary
to stop or reduce the pressure of the air supply in order to avoid producing the
excessive quantity of Smoke which is evolved from green coal and also to avoid
the cooling of the furnace which would result from the passage of air through the
fuel without entering into combination therewith.
The requisite change in the air supply is effected automatically according to this
Invention by the act of opening the furnace door. The stoker does not require to
move the air inlet valve which remains as adjusted for the normal working of the
furnace the passage of the air being controlled by a supplementary valve in the
D
-

page_text: same conduit which is connected by a series of levers with the furnace door as
hereinafter described so that when the latter opens this valve closes.
The door of the furnace is provided with a loop or eye to which is jointed a link
connected to a lever fixed on the end of a shaft-To the lower extremity of this
sbaft is fixed an arm terminating in an eye in which is inserted a pivot carrying a
hand lever provided with holes. The spindle or axis of the valve is provided with
a crank whose pin is capable of being inserted in any of the holes in the lever
herein before referred to.
When the furnace door is opened the levers are operated automatically and thus
close the valve to an extent that can be regulated by shifting the crank pin in the
holes in the lever.
An
According to another arrangement the valve is closed when the furnace door is
opened but opens again gradually after the door has been shut so as not to return
to its normal position until after a certain lapse of time-The rotary shaft
connected to the furnace door as hereinbefore described carries an arm jointed to
the end of a sliding rod which is capable of sliding longitudinally in guides
adjustable finger is fixed on this rod for the purpose of operating a lever upon the
axis of the valve. This lever forms part of a toothed segment in gear with a
second segment carrying a counterweighted pawl This pawl is capable of
engaging with the teeth of a ratchet wheel connected to a toothed wheel in gear
with a pinion on a spindle carrying a worm wheel driving a worm on a spindle
carrying vanes.
The effect of this arrangement is that when the furnace door is opened the
sliding rod is operated by the lever on the shaft connected to the furnace door and
the finger on the rod shifts the lever connected to the valve and closes the latter at
the same time lifting a counterweight which tends to keep the valve shut At the
same time the pawl slips over the teeth of the ratchet wheel without moving the
vanes When the door is shut the sliding bar returns drawing the adjustable
finger with it but leaves behind the lever arm on the axis of the valve spindle
The valve then commences to open under the action of the counterweight but the
pawl engages with the ratchet wheel and the motion of the valve is retarded by the
resistance of the vanes to an extent which may be regulated by changing the area
or resistance of the latter. The degree of opening and closing of the valve can be
adjusted by sliding the finger along the sliding rod
A similar result is obtained by providing the axis of the valve with an arm
which lifts a weighted plunger working in a pump barrel
When the furnace door is opened the valve shuts and the plunger is raised
When the door is shut the finger moves away from the lever the plunger then
descends under the influence of the weight and the valve opens slowly the
plunger being retarded in its descent by the resistance of the air in the pump
Cylinder the escape of the said air being controlled by means of a screw and sliding
valve
According to another arrangement the furnace door is connected by a link to a
lever fast on a vertical axis which by the intervention of an intermediate shaft
and bevel wheels imparts motion to the spindle of the valve-This valve is
independent of the valve which regulates the normal quantity of air blown into
the furnace being adjusted in the proper position by means of a crank and
Begment provided with pins and is not moved by the stoker when stoking
When the stoker opens the furnace door the link thrusts over the lever and its
motion is transmitted through the shafts to the spindle of the valve which
consequently closes as the door opens and stops the supply of air to the furnace.
When the furnace door is closed the movements are reversed and the valve is
free to open. but as it is necessary to admit air slowly and gradually so as to give
the green coal time to attain the temperature necessary for ignition the valve must
be brought back gradually to its original position
In order to obtain this result the wheel on the intermediate shaft imparts
motion to the said shaft by the intervention of a stop or catch so arranged that

page_text: the wheel is free to revolve upon the shaft when the furnace door is being shut-
On one end of the spindle of the valve is fixed a small crank connected by a rod
to a lever carrying a Counterweight A rod connected to the piston or plunger of
a cataract filled with oil is attached to this lever at a suitable. distance from the
fulcrum and has the effect of retarding the opening of the valve as in the
arrangement hereinbefore described
In order that the progress of combustion may not be interrupted when the
furnace door is opened simply for the purpose of inspecting the fire one of the
wheels is so connected to its shaft that when the furnace door opens this wheel
turns freely upon the shaft to a certain extent before coming into contact with a
stop on the said shaft which then causes the latter to rotate and open the valve
The stoker is thus enabled to open the door to a limited extent without operating
the valve.
The arrangements herein before described are sufficient to cause the consumption
of smoke with ordinary coals but when smoky coal is employed a certain amount
of Hydrocarburet may occasionally be evolved. This may be remedied by the
employment of a smoke consuming apparatus temporarily brought into action as
hereinafter described
During the time that the supply of air to the Ash pit is diminished and during
this time only a steam jet (turned on and off automatically) injects into the furnace
above the fuel, a sheet of steam and hot air which produces rapid ignition and
prevents the formation of smoke.
This apparatus consists of a steam pipe having a tapering extremity which enters
the trumpet shaped extremity of a mixing tube or nozzle contained in a case or
chamber of circular form in section at the base and gradually assuming an oval
form at the part which projects into the furnace.
The suction resulting from the steam escaping from the steam pipe draws in
air and gas from the furnace through the oval orifice of the Chamber and this air
and gas mingles with the steam in the nozzle-The gaseous current issuing from
this nozzle impinges against a plate spreading out in the form of a fan and
provided with projecting edges and longitudinal ribs so as to distribute the current
in the form of a sheet over the entire surface of the Coal.
Before entering the furnace the steam is dried in a chamber in which it
circulates in a thin stream round a bell so as to be separated from the water held
in suspension
The supply of steam to the drier is regulated by a valve operated automatically
as hereinafter described.
The plug of the steam valve is connected to a rod operated by the lever
connected to the cataract and which is provided with an eye or loop for the
reception of the end of the said rod.-The eye slides upon the rod and comes into
contact alternately with stops fixed thereon. When the long arm of the lever rises
on the opening of the furnace door it acts upon one of these stops pushes up the
rod and opens the valve..
The time that elapses before the valve opens is regulated by adjusting the
position of the stops on the rod so as to admit of the door being partly opened and
without admitting steam the time occupied in closing the valve being regulated by
the rate at which the cataract lever lets down the rod
This smoke consuming apparatus may be employed separately in which case the
steam valve is worked by the door by a combination of levers as described or:
otherwise and may thus be applied to any furnace working either with a blast of
air or by natural draught

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the
11th August 1883.
"
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN APPARATUS FOR CONSUMING SMOKE IN FURNACES'
a communication to me from La Compagnie du Chauffage Industriel Resident at
Paris in the Republic of France!
This Invention relates to means or apparatus for effecting the consumption of
smoke in furnaces by avoiding the admission of an excess of air and automatically
regulating the volume of air introduced underneath the bars and also in some
cases by employing a smoke consuming apparatus having a steam jet which is
automatically brought into action at certain times for a limited period as herein-
after described.
In carrying out this Invention when applied to furnaces working with a blast as
in the example illustrated in the accompanying drawings the air from a blower is
mixed with a certain quantity of burnt gases and delivered underneath the grate
in the usual manner and during the normal working of the furnace the proper
action is ensured by regulating the quantity of air admitted and by the introduction
of the mixture of air and burnt gases and also by moving the damper in the
chimney thus modifying the conditions of combustion under a slight pressure. S
When stoking or clearing the furnace however it becomes necessary to stop or
reduce the pressure of the air supply in order to avoid producing the excessive
quantity of smoke which is evolved from green coal and also to avoid the cooling
of the furnace which would result from the passage of air through the fuel without
entering into combination therewith.
'
In order not to make extra work for the stoker the requisite change in the air
supply is effected automatically according to this Invention by the act of opening
the furnace door. There is no occasion for the stoker to move the air inlet valve
which remains as adjusted for the normal working of the furnace the passage of
the air being controlled by a supplementary valve in the same conduit which valve
is connected by a series of levers with the furnace door as herein after described so
that when the latter opens this valve closes.
:
The stoker is thus at liberty to attend to the fire with a register or air inlet
valve that is neither too widely opened nor too closely shut and without being.
inconvenienced by an excessive supply of air.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the-same letters of reference
indicating corresponding parts in all the figures
3
Sheet 1 of the accompanying drawings illustrates an arrangement of mechanism 4
whereby the register or valve is connected to the furnace door at the same time
admitting of the angular displacement of the said register or valve being adjusted
as required.
Figure 1 (sheet 1) is a front elevation Figure 2 is a plan and Figure 3 is a side:
elevation of the apparatus.
4
A is the furnace door provided with a loop or eye B to which is jointed one
extremity of a forked link C the other extremity of the said link being connected
to a lever D This lever is fixed on the end of a vertical shaft E supported in a
footstep F and bearings G. To the lower extremity of this shaft is fixed an arm H
terminating in an eye H' in which is inserted a pivot I carrying a hand lever J E

page_text: provided with holes o. K is the spindle or axis of the valve and is provided with a
crank L whose pin a is capable of being inserted in any of the holes in the lever .
herein before referred to and in which it is secured by suitable means such as a
pin 6 Figure 3.
The effect of this combination is that when the furnace door is opened the free
extremities of the levers D and H will describe arcs of circles as shewn in dotted
lines in Figure 2 thereby moving the valve spindle K by the intervention of the
crank L and lever J and thus close the valve to an extent that can be regulated by
shifting the crank pin a in the holes in the lever J Figure 3.
Figures 12 and 3 sheet 2 illustrate in front view plan and side elevation
respectively an arrangement of mechanism for working the valve whereby the
valve is closed when the furnace door is opened but opens again gradually after the
door has been shut so as not to return to its normal position until after a certain
lapse of time. A rotary shaft A (which is an equivalent for the shaft E sheet 1.
being operated in a similar manner) carries an arm B jointed to the end of a
horizontal rod C which is capable of sliding longitudinally in guides D An
adjustable finger E is fixed on this rod for the purpose of operating a lever F upon
the axis G of the valve This lever forms part of a toothed segment H in gear
with a segment J turning on an axis I and carrying a counterweighted pawl K A
toothed wheel M on the axis I moves with the segment and pawl in one direction
only that is to say when the pawl engages with the teeth of a ratchet wheel L
connected to the said wheel M This wheel is in gear with a pinion N on a spindle
O and the rotary motion imparted to the latter is transmitted by the intervention
of a worm wheel P and worn Q to a vertical spindle R carrying vanes R'.
The effect of this arrangement is that when the furnace door is opened the
horizontal rod C is operated by the lever B on the shaft A and the finger on the
rod shifts the lever F connected to the valve and closes the latter at the same time
lifting a counterweight S which tends to keep the valve open. At the same time)
the pawl slips over the teeth of the ratchet wheel whilst the segment on the axis
of the valve spindle describes an arc of a circle.
When the door is shut the horizontal sliding bar returns drawing the adjustable.
finger with it but leaves behind the lever arm on the axis of the valve spindle.
The valve then commences to open under the action of the counterweight S but
the pawl K now engages with the ratchet wheel L and the motion of the valve is
consequently retarded by the resistance of the vanes R¹ The segment H on. the
axis G drives the segment J which is connected by the pawl K and wheel L to the
wheelwork actuating the vanes R¹. The opening movement is thus retarded to an
extent which may be regulated by adjusting the vanes so as to cause them to offer the
requisite resistance. The degree of opening and closing of the valve can be adjusted
by sliding the finger E along the horizontal rod C.
A similar result may be obtained according to the arrangement indicated in
elevation and plan in figures 4 and 5 sheet 2. The lever F is operated by the
finger E for shutting the valve as in the arrangement illustrated in figures 1. 2
and 3. On the axis of the valve is fixed an arm T which lifts a plunger U carrying
a weight X and working in a pump barrel V.
When the furnace door is opened the valve shuts and the plunger U is raised
When the door is shut the finger E moves away from the lever F the plunger then
descends under the influence of the weight X and the valve opens slowly the
plunger being retarded in its descent by the resistance of the air in the pump
cylinder the escape of the said air through a passage a being controlled by means
of a screw c connected to a sliding valve which can be made to uncover more or less
a port or opening b in the side of the passage a.
Sheet 3 illustrates an analogous arrangement of mechanism combined with a
device for consuming smoke by means of a steam jet. Figure 1 is a front elevation
figure 2 a transverse section figure 3 a rear elevation and figure 4 a plan of the
mechanism for operating the valve in the conduit or flue which conducts the air to
underneath the grate.

page_text: :
Figures 5 and 6 represent (in elevation and plan respectively) the furnace door
with the levers which effect the automatic action of the devices hereinafter
described.
Figures 7 and 8 are longitudinal sections taken at right angles to each other
along the lines 1-2 figure 8 and 3-4 figure 7 respectively and figure 9 is &
transverse section of the steam nozzle or injector this section being taken along the
line 5, 6 figure 7.
The furnace door A figures 5 and 6 is provided with a projection B to which is
jointed one extremity of a link C having a fork at each end The other extremity
of this link is likewise connected to a hand lever D fast on a vertical axis E
figures 1. 2. 3. 4. 5 and 6 which by the intervention of bevel wheels G and H
intermediate shaft F and bevel wheels I and J imparts motion to the spindle K of
the valve L This valve is independent of a valve M which regulates the quantity
of air blown into the furnace being permanently adjusted in the proper position for
the normal working by means of a crank N and segment P figure 3 provided with
pins p and is not moved by the stoker when stoking.
When the stoker opens the furnace door the link C thrusts over the lever D the
shaft E revolves and its motion is transmitted through the shaft F and wheels I. J.
to the spindle K of the valve L which consequently closes as the door opens and
stops the supply of air to the furnace
When the furnace door is closed this motion of the door tends to reverse the
movements of the link C lever D and the rotation of the shafts E F K and open
the valve L-To obtain perfect combustion however combined with the maximum
of economy it is desirable that the green coal spread over the grate should not be
immediately traversed by a large volume of air which would chill it and set up an
excessive and flamless distillation resulting in smoke-In order to prevent this it
is necessary to admit air slowly and gradually so as to give the fresh coal time to
attain the temperature necessary for ignition--In short the valve L must be brought
back gradually to its original position
In order to obtain this result the arrangement hereinafter described is employed.
In shutting the valve L the pinion J imparts motion to the spindle K by the
intervention of a stop or catch so arranged that the wheel is free to revolve upon
the spindle when the movement is reversed that is to say when the furnace door
is being shut. On one end of the spindle K of the valve is fixed a small crank J'
connected by a Rod Q to one extremity of a lever R oscillating on a fixed point 0-
At the other extremity of this lever is suspended a weight S A rod connected to
the piston or plunger of a cataract T filled with oil is attached to this lever at a
suitable distance from the fulcrum and has the effect of retarding the rotary
motion of the spindle K-Under these conditions the valve L opens gradually and
occupies say sixty, one hundred or one hundred and twenty seconds before the air
is readmitted to the furnace at the normal rate.
In order that the progress of combustion may not be interrupted when the
furnace door is opened simply for the purpose of inspecting the fire the mechanism
is so arranged as to enable the door to be opened to a limited extent without
affecting the supply of air-The wheel J is carried upon the spindle K in such a
manner that when the furnace door opens this wheel turns freely upon this spindle
to a certain extent before coming in contact with a stop which enables it to cause
the spindle K to rotate and open the valve L-The stoker is thus enabled to open
the door to a limited extent without altering the supply of air.
The arrangements hereinbefore described are sufficient to cause the consumption
of smoke with ordinary coals but when very smoky coal is employed a certain
amount of combustible gas may occasionally be evolved-This may be remedied by
the employment of a smoke consuming apparatus temporarily brought into action
as next hereinafter described-During the time that the supply of air to the ashpit
is diminished and during this time only a steam jet turned on and off automatically
injects into the furnace above the fuel a sheet of steam and hot air which produces
rapid ignition and prevents the formation of smoke.

page_text: The apparatus for injecting steam and hot air above the bars is illustrated in
Figures 7. 8 and 9 and consists of a steam injecting tube a having a tapering or
contracted extremity a¹ which enters the trumpet shaped extremity of a mixing
tube or nozzle b-These tubes are contained in a chamber.c of circular form in
section at the base and gradually assuming a flattened or oval form at the part
which projects into the furnace as shown in Figure 9.
The suction resulting from the steam escaping from the tube a draws in air and
gas from the furnace through the oval orifice of the chamber c and this air and gas
iningles, with the steam, in the tube b-The gaseous. current issuing from the
nozzle b impinges against a plate d' spreading out in the form of a fan and which
may be provided with projecting edges and longitudinal ribs so as to more
effectually deflect and distribute the current in the form of a sheet over the entire
surface of a coal.
The steam obtained from any convenient generator is conducted by a pipe e
(Figures 1 and 2) to a chamber in which it is caused to flow in a thin, stream
round a bell g before entering a pipe h Figures 2. 3. 5 and 6 leading to the apparatus
illustrated in Figures 7 and 8 so as to be separated from the water held in suspen-
sion which is drawn off through a purge cock i and the steam is thus delivered
to the nozzle or injector in a perfectly dry condition-The supply of steam to the
steam drying apparatus f is regulated by a valve; operated automatically as herein-
after described The valvej has a plug k provided with an arm k¹ connected to a
rod operated by the lever R (figures 1. 2 and 4) which is provided with an eye
or loop n for the reception of the end of the said Rod-This eye n slides upon the
rod and comes into contact alternately with stops m and n¹ When the long arm
of the lever rises on the opening of the furnace door it acts upon the stop m pushes
up the rod and opens the steam valve j-The time that elapses before this valve
opens is regulated by adjusting the position of the stops m and n on the rod Z so
as to admit of the door being partly opened without admitting steam the time
occupied in closing the valve being regulated by the rate at which the lever R
allows the rod to descend.
This smoke consuming apparatus completes the arrangement hereinbefore
described for automatically operating the air inlet valve and is applicable to
furnaces with a blast but may be employed separately in which case the steam
valve is worked by the furnace door by a combination of levers arranged as herein-
before described or otherwise and may thus be applied to any furnace working
either with a blast of air or by natural draught
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and
original and therefore claim as the Invention secured to me by the hereinbefore
in part recited Letters Patent is-
First In furnaces supplied with air under pressure or otherwise the employ-
ment of a combination of mechanical devices as hereinbefore setforth enabling
the valve or register controlling the supply of air to shut automatically when the
furnace door is opened and to open in like manner when the door is shut
substantially as hereinbefore described and illustrated in the accompanying
drawings
Second-In furnaces supplied with air under pressure the method of interrupting
the supply of air during the time of stoking substantially as hereinbefore described
and illustrated in the accompanying drawings
Third In furnaces supplied with air under pressure or otherwise the employ.
ment of means for effecting the gradual readmission of air during the period
immediately following the stoking substantially as hereinbefore described and
illustrated in the accompanying drawings
Fourth Effecting the consumption of smoke in furnaces by means of steam
nozzle or injector constructed and arranged as hereinbefore set forth drawing heated

page_text: gases from the interior of the furnace and blowing steam mingled with these gases
in a thin sheet over the surface of the fuel
Fifth-The apparatus for drying steam constructed and arranged as herein-
before set forth in which the steam is drawn out and separated from the water, of
condensation and from the water held in suspension before being admitted to the
furnace substantially as herein before described and illustrated in the accompanying
drawings
Sixth The combination of mechanism substantially as herein before setforth for
enabling the valve controlling the admission of steam to the furnace to be operated
automatically by the furnace door substantially as hereinbefore described and
illustrated in the accompanying drawings
Seventh-In furnaces the combination of devices or means 'for effecting the
consumption of smoke substantially as herein before described and illustrated in
the accompanying drawings
In witness whereof I the said John Henry Johnson have to this my
Specification set my hand and seal this tenth day of August One thousand
eight hundred and eighty three
J. HENRY JOHNSON (L.S.)