Improvements in Apparatus for Regulating and Controlling the Admission of Air to Flues and Passages of Boilers or other like Heating Apparatus.
Year: 1890

page_text: Date of Application, 11th Mar., 1890-Accepted, 10th May, 1890
COMPLETE SPECIFICATION.
Improvements in Apparatus for Regulating and Controlling the
Admission of Air to Flues and Passages of Boilers or other like
Heating Apparatus.
A communication from abroad by FRIEDERICH OTTO HÖRENZ, of 80 K, Meissner-
strasse, Radebeul, Dresden, in the Kingdom of Saxony, in the Empire of
Germany, Manufacturer.
1, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, and 323, High Holborn, in the County of Middlesex, Civil.
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 automatic regulating and controlling apparatus for flues
and air admission pipes in heating apparatus.
In boiler furnaces with plain grates, the stoking is usually performed in the
following manner, namely:-
-
The stoker, from time to time, opens the furnace door and throws some shovelfuls
of coal or the like on the glowing fuel almost burnt through. As, by this opening of
the door, a much stronger draught of air rushes through the fire box, and, as the cold
air passing through naturally causes a considerable loss of heating gases or fuel,
thero has hitherto frequently been a damper fixed in the flue, which is closed during
the refiring. This flue damper has been usually arranged in such a manner that it
closes automatically on the opening of the door and vice versa-on the closing of the
door opens again automatically. This is a great step in advance, as the stokers, in
most cases, neglect to close the damper in the flue as soon as they know they are not
supervised.
As
Further, however, the arrangement of the dampers in the flues affords means for a
further highly important advantage in the heating process itself. It is clear, that the
strongest draught is required immediately after the throwing on of fresh fuel.
the fuel most recently thrown on becomes gradually heated, the whole fire sinks
gradually together and soon leaves the grate uncovered with fuel in several places.
Partly owing to these uncovered spaces and partly owing to the mass of fuel becoming
constantly more burnt through, an altogether disproportionate quantity of air is
drawn through the fire box unless the draught of the furnace be reduced.
As any one can ascertain for themselves at any regulating furnace, it is exactly
when the combustion is approaching the end that the fuel yields the most caloric and
consequently needs the least draught. It is therefore at once apparent that an
altogether useless consumption of fuel is thereby brought about, in that the draught
between one stoking and the next passes through the furnace grate with undiminished
strength, it is therefore important to use the dampers inserted in the furnace flues
(which may be replaced by slides or similar arrangements) in order to reduce the
draught passing through the fire box as far as possible, so that it will correspond with
the progress of combustion.
A rational mode of heating would therefore demand the gradual closing of the flue
dampers during each period following the charging, and the complete closing of the
dampers or slides during the stoking itself. If the regulation of the damper or slide
is worked by hand, experience shows that it is attended to only as long as the stoker
knows that he is under supervision. It is therefore of special importance to find an
apparatus which affords a constant regulation of the position of the damper. If the
gradual movement of the damper can be automatically brought about in a suitable
manner, a great practical advantage is thereby attained. As a matter of fuct,

page_text: attempts have already been several times made to achieve an automatic regulation of
the draught without however a practical satisfactory result being attained, as the devices
used for this purpose, such as valve gears and the like, from their intricacy do not
allow of an extended practical employment. In order to practically meet all the
above named difficulties, the regulating device forming the object of this invention is
arranged in such a manner that with a comparatively very simple construction
employing a clockwork it brings about :-
1st. An automatic closing of the draught damper during the charging.
2nd. A gradual automatic closing of the draught damper during each period after
charging.
3rd. It is very easily set for varying periods of duration of the combustion (after
Figure 4 represents the controlling device on a larger scale, and
Figures 5, 6 and 7 represent various means of transmitting the motion from the
clockwork to the draught damper, which, as is self-evident, can be easily replaced by
a slide.
The throttle valve A, (Figure 1) serving to regulate the admission of air, revolves
on the trunnion a and is provided with a double armed lever B; at both ends of the
latter two chains b and b¹ engage.
These chains are attached to a wheel C, which is rotated by means of clockwork. A
segment D is arranged on this wheel, which, at each revolution of the wheel C, winds
up the chains b and 6' in one or another direction. By means of this segment, as will
be easily perceived, the result is attained that the throttle remains closed for a time
even when the clockwork moves further on. In this manner, a person may allow the
burnt through fire to remain with the throttle valve almost fully closed for some time
before re-stoking. The throttle valve A is opened or closed in the above described
manner. Figure 1 shows the position, when closed, in which the chain b has wound
itself on the segment, whilst the chain 6' is slack.
The clockwork which moves the wheel C is driven by means of the weight F, the
string or chain of which is wound on the drum E of the axle c. If the clockwork
be run down, it is wound up again by means of the handle G, the string or chain g is
wound in a contrary direction on the drum E. By this winding up of the clockwork,
the throttle valve A is immediately again opened. In order that the stoker may be
notified each time that the throttle valve is entirely opened or entirely shut, an
arrangement is attached by which an alarm sounds when the clockwork is quite
wound up and when, consequently, the throttle valve is entirely opened, and by which
another signal sounds when the clockwork has entirely run down and consequently
the throttle valve is entirely closed.
For this purpose two pins and k are fitted on the drum E, (Figure 4) of which
k acts on the arm o on the winding up of the clockwork, and on the arm m on the
running down of the clockwork.
The arm o is attached to the axle O on which the arm 0% of the clapper of the
bell U is fitted.
If the clockwork be wound up by means of the handle G, the pin k takes a
position behind the arm o and presses the same back in the direction of the arrow
shown; whereby the clapper of the bell U is moved to the left. The pin k is arranged
on the drum E in such a manner that it slips from off the arm o shortly before the
weight F is quite drawn up. The clapper then strikes on the bell U and gives the
stoker the signal that the clockwork is wound up and the throttle valve is quite

page_text: opened. On the running down of the clockwork, on the other hand, the pin / comes
into action, catches behind the arm m of the axle M and pushes the same to the left,
as shown by the arrow.
"
The arm m¹ is thereby pressed downwards and works by means of the arm r, fixed
on the cam R, in such a manner on the shank of the clapper t, movable around T, of
the bell v, that the clapper is moved away from the above named bell. When, by the
continued motion of the drum E, the pin slips away from the arm m, the latter
swings back by reason of the action of a spiral spring seated on the axle and the
bell is struck by the clapper as a signal that the throttle valve is closed. In order
to prevent a further revolution of the drum, a pin h (Figure 2) is provided on the
same which comes against the projection i as soon as the bell has been struck.
.
In order to be able to easily alter, as may be desired, the lengths of time during
which the clockwork is running down, that is the period following the stoking up,
the following arrangement is made use of :-
The main driving wheel 1 (Figure 3) works by means of the wheels 2, 3, 4, 5, and 6
on the balance wheel 7, one of the catches of the latter is movable round the axle Z' on
which a forked arm Z', which hangs downwards, is fitted and which catches the lower
part Z of the pendulum. The pendulum consists of the well known rod Z forming the
lower part and a rod forming the upper part connected with it by means of a spring
plate y
The latter rod a can be inserted in the sheath W and fixed at any required height
by means of the screw x¹.
The duration of the swing of the pendulum and therewith the time for the running
down of the clockwork can in this way be very easily and simply varied within the
required limits.
In an existing model, the period after each firing can be varied thus between 8
and 40 minutes and any stoker can bring this about by a few simple turns of the
handle, as soon as a stronger or weaker firing is required.
In order to always keep an exact check on the fireman, an arrangement is
attached which is set in action on the striking of the bells and which makes
corresponding holes on a paper disc connected with an ordinary clock and set in
motion by the same.
The two prickers S₁ and S2 (Figure 4) are arranged one above the other. The
pricker S which works on the winding up of the clockwork is set in action in the
following manner :-
The pricker S' is fastened on a socket P which is loosely movable on the axle M
and is provided with an arm p.
An arm o attached to the axle O strikes against this arm p. If now by the
winding up of the clockwork the arm o is pushed away from the pin k, to the right,
the arm of raises the arm p of the socket P and the pricker S₁ sticks into the paper
disc. The other pricker S', which must stick into the disc on the running down of
the clockwork, is fixed on the axle N which is provided with an arm n projecting
forwards. A short arm m' attached to the axle M works on this arm n, which
arm (m), on the slipping away of the pin from the arm m, presses downwards.
The axle N makes then a slight revolving movement and the pricker S³ sticks into a
paper disc.
Of course several of the methods of constructing the various parts can be altered or
replaced by others.
The clockwork driven by a weight may be replaced by one driven by a spring.
Further, the registering and alarm devices may be actuated in other ways and
sound signals may be replaced by sight ones. The connection of the drum C,
especially with the throttle valve A or with any desired slide, may be altered in
numerous ways. In Figure 5 this connection_is_brought about by a single chain
which can be partially wound on both rollers. In Figure 6 the axle cand the axle a
are each provided with an arm and both arms are connected by a rigid rod.
When chains are used, in this case equally with the arrangement depicted in
Figure 5, counter weights must be made to work on the throttle valve axles.

page_text: Finally, as depicted in Figure 7, the clockwork could be made to act direct on the
throttle valve.
Nothing is altered in the principle of the invention if the dampers are arranged in
the air admission passages instead of in the flues.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. An apparatus for automatically regulating the admission of air to boiler furnaces
or the like, characterised by the combination of a closing device arrangement in the
flues or air passages with a clockwork mechanism driven by weights or springs, which
latter, if wound up when the said device is open, closes the same as the process of
combustion progresses, substantially as shown and described.
2. In a clockwork for the automatic closing of flues or air passages, the combination
and arrangement of the devices for regulating the time of running down, comprising
a pendulum xyz, a holder W in which the upper part is contained, a spring plate y
for connecting the upper part a with the lower part 2, whereby the latter engages
with a forked arm z¹ connected with the catch of a ratchet wheel, substantially as
described and shown.
3. In a regulating device such as described, the arrangement of a segment D on
the drum C of the clockwork round which segment the chain b, serving for the
gradual closing of the throttle valve or damper, is wound in such a manner that, in
spite of the clockwork continuing to operate the throttle valve when opened, it
remains open for a time, and similarly when it is closed, it remains closed for a time,
substantially as described and shown.
4. The combination with a regulating device for flues of a signalling apparatus
substantially as herein shown and described and for the purpose specified.
5. In regulating devices for flues, the combination and arrangement of a controlling
apparatus adapted to register both the termination of the combustion period herein
referred to and the re-opening of the throttle valve or damper by means of an
ordinary time meter, substantially as shown and described.
Dated this 10th day of March 1890.
WM. P. THOMPSON & Co.,
Agents for the Applicant.