Improved Method of and Apparatus for Regulating the Admission of Air to Furnaces according to Variations in the Weight of the Furnace Gases
Year: 1895

page_text: Date of Application, 30th Apr, 1895
Complete Specification Left, 30th Jan, 1896-Accepted, 30th Apr, 1896
PROVISIONAL SPECIFICATION
Improved Method of and Apparatus for Regulating the Admission
of Air to Furnaces according to Variations in the Weight of the
Furnace Gases
I, MAX ARNDT of Monheimsallee, Aix-la-Chapelle, Germany, Engineer, do
hereby declare the nature of this invention to be as follows
It is known that the larger the quantity of carbonic acid in smoke or furnace
gases the greater is the weight of such gases and this invention has foi object to
utilise this difference of weight for the purpose of regulating the supply of
atmospheric air to furnaces
Said
In carrying out the invention some of the gases of combustion are withdrawn
continuously from the furnace flue and passed through any suitable kind of gas
balance on through an aerometer which may serve as a gas balance and the
oscillations of the gas balance occasioned by the difference from time to time in
the specific gravity of the furnace gases are carried over to a body which is in
connection with an electric or other kind of appuitus by which valve slide or
damper or the like may be operated for admitting an to the furnace I he electric
apparatus consists of suspended frame provided with an armature and in con-
nection with an oscillating part of the gas balance, an electro magnet, three
conducting pieces and an insulating part Fiom time to time the electro magnet
receives through any suitable contact arrangement an electric current
ari angement may for example be in the form of clock work which sets in motion a
sliding contact having a stud dipping into a quicksilver contact or otherwise
connected to form a conductor The sliding contact from time to time comes in
contact with a contact spring and closes an electric encuit whereupon the clectio
magnet attracts the armature and with it the oscillating part of the gas balance
The movement of the mature may be enried over to levers for operating clutches
of winding mechanism by which a slide or damper may be operated to open or
close so as to increase or diminish the supply of atmospheric air to the furnace or
there may be more than one magnet or more than one armature or more thin one
clutch or operating level
Instead of the electric apparatus an air pressure apparatus may be employed
in connection with the gas balance the fluctuations of which are carried over to two
valves within a compressed air casing When the oscillating part in connection
with the gas balance moves sufficiently high it admits compressed past one of
the valves to one side of a piston moving in a cylinder This sets the piston in
motion to operate through suitable connections a slide on damper for regulating
the admission of air to the furnace When the oscillating part moves lower it
operates the other valve to admit compressed air to the other side of the piston
which thereby communicates a reverse movement to the slide or damper or
equivalent In the mid position of the oscillating part neither valve is operated
Instead of electric on an pressure apparatus water and other pressure apparatus
may be employed in connect with the gas balance and the apparatus inay be
variously modified
Dated this 30th day of An 1895
CAPITAINE & VON HERTLING,
89 Chancery Lane, London, WC, Agents for the Applicant

page_text: Improved Method of and Apparatus for Regulating the Admission
of Air to Furnaces according to Variations in the Weight of the
Furnace Gases
I, MAX ARNDT of Monheimsallee, Aix-la-Chapelle, Germary, 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 known that a loss of heat takes place in furnaces when too much air is
supplied thereto as then the excess air is uselessly heated to the high temperature
of the withdrawing gases
If so much air were supplied to a fuel as would be exactly requisite for its
perfect combustion, there would result, as the final product of the combustion
of carbon and oxygen is carbonic acid, smoke gas having 21 per cent of its
volume carbonic acid because the atmospheric air contains 21 per cent of oxygen
The carbonic acid is about 1 times heavier than atmospheric air and the other
chief component parts of smoke gas, which therefore must be the heavier the
larger its contents of carbonic acid, but if to the fuel is supplied too much an and
the carbonic acid contents of the smoke gas as well as the latter diluted the gas
will then be lighter The specific gravity of the smoke gases therefore determines
the economy of a furnace which economy is the greater, the larger up to a certain
practicable limit, the percentage volume of carbonic acid contained in the smoke
gas, that is to say the heavier this is
૧
This invention has for object to utilise said difference of weight for the purpose
of regulating economically the quantity of air flowing to the fuel, and this object
is attained by passing portion of the gases of combustion, continuously taken
from said gases, through a suitable gas balance or through an aerometer or the
like serving as gas bilance, and transmitting the oscillations occasioned by the
difference in the weight of the gases to any suitably formed body taking part in
such oscillations and which in conjunction with the apparatus shewn in the drawing
governs the supply of air for combustion
In the accompanying diawing
It
Fig 1 shews an electric regulating mechanism for the purpose stated
comprises a frame or rod G suspended from any suitable part of the gas balance
an oscillating body B carried on the end of said frame or rod G and provided
with an aimature A, an electio magnet M, three conducting pieces C, D, E, and
an insulator Y
The electro magnet M receives current from time to time through
any suitable contact mechanism, for example through a clockwork I setting in
rotation the disc H¹ which carries along with it by friction a sliding contact II
dipping by a stud L into a quicksilver contact K or otherwise connected to conduct
the current The requisite friction between the disc H¹ and the sliding contact H
is obtained by means of a leather or like washer H3 screwed on to the horizontal
part of said sliding contact By this means the sliding contact H has motion
tiansmitted to it and upon each revolution comes by its vertical arm H' m
contact with, and slides upon, the contact sping F and thus closes the electric
circuit 1, 2, 3, 4, 5, 6, 7, whereupon the electro magnet M attracts the armature A
and therewith also the oscillating body B which then by its projecting parts a, b,
produces, at the points corresponding to the position at the particular moment of
the moving parts of the balance, an electrical contact between the conductor C and
one of the two conductors D or E which two latter are separated from one another
by the insulating part I so that they can never both receive current at the same
time The rib c of said insulator Y is so located that the part a of the oscillating

page_text: body B comes opposite thereto when air is supplied to the fuel in the furnace in an
economically proper proportion or quantity and the gas in the balance is of the
weight corresponding to this proportion, consequently the rib c has for object to
prevent electrical contact from taking place when the part a of the oscillating
body comes against said b in which case neither of the two conductors D, E,
receives current
The purpose of this regulating mechanism is, when the circuit is closed by means
of the oscillating body B, and the current passing either through the conductor D
or the conductor E, to utilise said curient in a suitable n inner for opening and
closing the damper or slide of a furnace flue so that the supply of air to the fuel is
regulated conformably to the requirements of the moment
Fig 2 shews on a small scale as compared with that of Fig 1 a winding mechanism,
the dium t of which actuates, through the 1ope or chun passing over pulleys,
the damper S of a furnace flue O The drum t is actuated through the shafts w¹
to w the sets of bevel toothed wheels to r thereon and the screw or woim s
engaging teeth on said drum, but only when one of the two powerful electro
magnets m² or m² receives cuirent and through lever provided with m
tures a, a, operates one of the two couplings 1, 2, carried on shaft w' Each of
the two electro magnets 19, through conductor 9,8,17, or through conductors 16
and 21, in connection with the conductor C (Fig 1) but the magnet m' is through
conductor 18 to 20 in connection with the conductor E only, and the magnet m²,
through conductor 12 to 1o with the conductor D only
If for example the gases of combustion of an ordinary flat giate furnace contain
cubonic acid to the extent of about 16 per cent of then volume which proportion
corresponds to too small supply of air for combustion, the oscillating body B,
when the conductor D (Fig 1) is in operation for permitting the electric current
to operate the damper S, would be at about the height it is shewn in Fig 1 and
the iegulation of the supply of air of combustion would take place the follow ng
mannei
Magnet M receives current through sliding contact at 3, and attracts by its
armature A the oscillating body B so that this latter by put b comes in contact
with the conductor C and by put a with the conductor D I hereupon the
magnet m² (Fig 2) by the clo ure of the circuit in the wire on line 8, 9, 10, 11, 12,
to 17, attracts by means of aimature a², the level h This latter draws into ge ir
the coupling of the continuously rotating shaft w¹ and then, if this rotates in the
direction shewn by the arrow brings about through gearing 1,2, shafts w, w, and
screws a rotation of the drum t in the duection indicated by the arrow so long as
the circuit remains closed thus opening wider the da npei S and causing more air
to flow to the furnace The circuit remains closed but a short time and the lever h
returns to its middle position so soon as the electric circuit is broken
If too much air passes to the fuel the gases of combustion aie consequently
lighter and the oscillating body B is raised to a higher position in which it effects
with conductor E the closure of the cucuit, the electric current then passing in the
line 8 9, 10, 11, 18, to 21 and 17 to the magnet m which then attracts the
armature a¹ and through lever brings the coupling to engagement so that
the drum t is diven through gearing 3, 4, shafts w³, w, and screws in a duection
contrary to that indicated by the arrow, the damper S then being more closed and
the flow of air to the fuel thereby diminished
Fig 3 shews by way of example a complete gas bilance with the casing thereof
extended downwards and the aforesaid regulating mechanism located thei ein
underneath the gas balance, but said mechanism may be located in any other con-
venient place
W1, W2, are weighing bodies the former being suiiounded by air
and the latter by the smoke gases to be weighed which latter are conducted in the
dtection shewn by the arrows 1, 2, through a gas vessel x surrounding the weighing
body W2
The weighing bodies W1, W2, are hung from the balance beam
the indicating pointer of the balance When the smoke gas is heavy the weighing
body W is driven upwards and the pointer V moved from left to right, when
V 15

page_text: lighter, the contrary movement takes place The oscillations of the balance are,
through rod G, carried over to the oscillating body B The drum or the clock
This is
work mechanism T miy at the same time serve for registering purposes
effected by an electro magnet m³ attracting from time to time a pressure lever d
which presses a swinging body attached to the end of suspen.ion rod G' against a
registering sheet fixed to the rotating drum and thus marks the sheet The drum
or casing t of the clockwork thus seives for registering or recording the oscillations
of the oscillating body B I he drum t is mounted loose upon the plate t2 which is
fastened to the fiame t¹ The dium is fixed on the axis t³ This latter is rotated
by the clockwork within the dium
Fig 4 shews in horizontal section a modification in the arrangement of the
regulating mechanism Whilst in Fig 3 the regulating mechanism is arranged in
the bottom extension of the casing and the oscillating body B is suspended through
the rod G to an aim of the balance beam, in Fig 4 the regulating mechanism is
fixed direct to the column U of the balance by means of insulating part J and the
oscillating body B with armature A is fixed to the pointer V of the balance and
swings with said pointer in a vertical plane Referring to Fig 4 the insulating
part J cares the conductors C, D, E, and the electio magnet M 1 he oscillating
body B with mature A is in connection with the indicating pointe: V of the
balance by means of a light sping N
The functions of this mechanism are like
those of the mechanism previously described The magnet M by means of
armature A attracts from time to time the oscillating body B and thereby produces
contact between conductors C and D oi conductors and E
Fig 5 shews a method of driving the shaft wl with sciew or woim s direct by 1
small electro motor e, which receives current through one of the two conductors E
or D (Fig 1) of the regulating mechanism only duing the contact of the sliding
contact H at 3 and for the night hand and left hand rotation of the shaft wis
electrically reversed in any suitable and known minner the screw thereby operating
winding drum t like the screws in 11 2 The shaft w may also be formed as
a screw spindle for worl ing in a known minnet a screw nut in connection with and
moving and regulating the damper S
Fig 6 is a diagrammatic view of a mechanism by means of which the direction of
rotation of the dium t is changed by the use of a pressure medium, compressed at
for example, which by pissing again t the one or the other side of the piston p
drives said piston in 2 manne similar to that shewn in Fig 7, hereinafter
described, and sets in or out of engagement as may be required the couplings k', k³,
(Fig 2)
Finally Fig 7 is a diagrammatic view of pneumatically actuated regulating
mechanism in which the oscillating body B is hung upon the 1od G suspended
from the gas balance Sud body may oscillate without friction between two
frames,, which carry plates D, E, and are in connection with valves ', v²,
located within an air casing to which arefied or compressed air is supplied in
the direction shewn by arrow 23 Said air casing by its extensions g', g², and by
pipes, 2, is in communication with a cylinder 2, the piston p³ of which is operated
from the valves v', 22, of the an casing Zi Underneath the latter is a cylinder
with piston p', piston rod and air casing to which latter rarefied or compressed
air is supplied in the direction shewn by arrow 22 and within which is a valve v
that may be opened at certain intervals of time by any suitable means, for example
by means of a rotating disc u, projection n' thereon and lever with projection n
At the upper part 2 of the frame C¹ there is a rib c, which in this case as in the
electric mechanism shewn in Fig 1 has for object to keep the damper S stationary
when the part a of the oscillating body B comes against said rib as occurs when
the weight of the smoke gas in the balance corresponds to proper supply of air
for combustion purposes and when an alteration of the damper opening is not
required
It now for the regulation of the damper the valve is opened, the piston p
actuated, say by compressed an, will through rod 9 press the oscillating body B

page_text: with the part b against the frame C¹ and with the part a, according to the height
of its position at the time either against the plate D¹ or against the plate E₁ or
against the fixed rib c By the pressure of the oscillating body B against the
plate D', the valve is opened and the piston p² 15 pressed to the right, but if the
part a comes against the plate E' the reverse motion takes place
The movements of the piston p³ are utilised for actuating any further suitable
mechanism for opening and closing the damper S The exhaust compressed
air can pass out of the cylinders ', 2, through small orifices xx
The same regulating mechanism may also be actuated by water pressure on by
other suitable pressure medium Further the mechanisms hereinbefore described
may be applied to operate flaps slides, Venetian shutters and the like, which may
be provided in the front pait of the furnace and generally to all arrangements
having for object to increase or diminish the passage of air to the fuel
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 A method of regulating the admission of air to the fuel of a furnace in
economical measure according to variations in the weight of the furnace gases,
consisting in conducting gases continuously withdrawn from the furnace flue
through a gas balance (or aerometer or the like serving as a gas balance) to which
is applied an oscillating body B which, accompanying the oscillations of the
balance, is utilised to actuate regulating mechanism which operates that part or
those parts in connection with the furnace that has or have for object to regulate
the supply of au to the fuel, such as dampers, slides, flaps and the like, substantially
as described and shewn
2 For carrying out the method referred to in Claim 1, a regulating mechanism in
which the oscillating body B suspended from the gas balance is from time to time
attracted by the electio magnet M to the electric conductors C and E or C and D
(Figs 1, 3, 4) or pressed by a suitable pressure medium through the piston p and
piston rod 9 or other means against the frame C¹as also against one of the plate
shaped bodies D, or E' (Fig 7) so that the oscillating body B according to its
position relatively to the stand of the gas balance or to the weight of the gas,
establishes at intervals by electrical action, contact between the conductor and
one of the two conductors D or E, or by operating through a pressure medium,
that is to say, by pressure against one of the two bodies D' or E¹ a valve or
slide v or v² is opened and the pressure medium conducted through pipe 1 or 2
into a cylinder 2 so that in this case the movements of a piston p² as distinguished
from the action of the current given off by the conductor D or E may be utilised
either for the direct working or for the reversal of other mechanisms for operating
the damper or slide or flap or the like, whilst the regulating mechanism does not
permit an alteration in the supply of air when the oscillating body B comes by its
suitably formed part a against the part c of the insulator Y (Fig 1) or of the upper
part C3 of the frame C₁ (Fig 7), substantially as described and shewn
Dated this 30th day of January 1896
CAPITAINE & Vov HERTLING,
89 Chancery Lane, London, WC, Agents for the Applicant