Improved Regulator for Low Pressure Heating Apparatus.
Year: 1891

page_text: Date of Application, 20th Oct., 1891
Complete Specification Left, 19th Mar., 1892-Accepted, 15th Oct., 1892
PROVISIONAL SPECIFICATION.
Improved Regulator for Low Pressure Heating Apparatus.
I, FRANZ WAGNER of Markt 5, II, Crimmitschau, Germany, Gentleman, do
hereby declare the nature of this invention to be as follows:-
An
This invention relates to a regulator for low pressure heating apparatus in which
is arranged a hood or bell (hereinafter called a bell) movable in an annular
channel and sealed with a liquid, the arrangement being such that the said bell
rises within a vertical pipe forming the outer wall of the annular channel, when the
water attains a certain level, and contracts or closes a passage or passages for the
admission of air to the grate of a stove, by means of a closing device.
arrangement is provided such that at a certain height of pressure water in the
vertical pipe, the bell rises until it strikes against a weight whereby its stroke is
limited for the time being and the closing device is closed, but so that when the
column of pressure water in the vertical pipe rises beyond a further limit, the
bell will raise the weight and thereby open a channel which conveys the air behind
the grate.
Fig. 1 and 1 illustrate the regulator in its simplest form. It consists of a
movable part comprising the bell h, the short vertical pipe s, and the air valve l,
and a stationary part comprising two concentric tubes and g¹ that form between
them the annular channel r. The bell is inserted within this channel, and is
capable of moving vertically therein. The interior of the inner tube g is connected
at its lower end by a short pipe g³ with the vertical boiler pipe H of the low
pressure boiler. The movable part of the regulator is also connected with the
main vertical pipe H by means of an india rubber tube 8'; this connection being
effected by means of the short vertical pipes in such a manner that the bell h
can rise and fall without hindrance. The regulator is connected with the vertical
pipe H in such a manner that its base is situated slightly above the highest boiler
water level.
The annular channel is partly filled with mercury so that between the bell h
and the stationary part of the regulator is a space G* which is connected at top
and bottom only with the main vertical pipe H.
The buoyancy of the bell h dipping in the mercury need not be considered
with relation to the weight of the entire movable part; the bell h will therefore
when in the state of rest, rest upon the bottom of the channel.
The vertical pipes has within the bell a tubular extension e the object of
which will be explained further on.
The operation of the regulator is as follows:-
With increasing steam pressure in the boiler, the water will be forced into the
vertical pipe H and will pass through the lower connecting pipe 9³ into the
internal space G* of the regulator. Here it will rise until the water level reaches
the lower mouth of the tubular extension e. Since the space above this level is
shut off from the external atmosphere, and also from the vertical pipe H, the
rising water can only take its further course through the pipe e, thereby shutting
off the space G*, which is full of air and the capacity of which is determined by
the length of the tubular extension e. The water will continue to rise in the
extension and pipes and after passing through the india rubber pipe s¹, will
again unite with the water in the main vertical pipe H.
It will be readily seen that when the interior of the tube g is filled with water
and air as described, the bell and the mercury will be subjected to the pressure
of a column of water, the height of which corresponds to the difference in height

page_text: between the plane of the top or cover of the bell and the plane of the water level
in the main vertical pipe H.
This pressure will manifest itself in a twofold manner:-First it will cause a
difference in level of the mercury which is enclosed between the bell h and the
tube g, as compared with the mercury column which is enclosed between the bell h
and the outer tube g', this difference between the two mercury levels corresponding
to the ratio of the specific weights of water and mercury, being 13.6 times as small
as the already mentioned difference (which produces the pressure) between the
height of the water level in H and the top of the bell.
The second effect of the pressure consists in its tendency to raise the bell h
which is movable vertically.
The weight of the bell, pipes with extension e, and the air valve l, is made
such that the movable part of the regulator will be raised only when there is a
column of water of about 2.5 metres in height in the vertical pipe H, at which
time the air valve will be moved nearer to the opening of the passage for air to
the fire grate, and finally will entirely close this passage. This water column
corresponds to a pressure of about of an atmosphere in the internal space G*
of the regulator. The two mercury columns hereinbefore mentioned will therefore
then shew a difference in level of centimetres == 19 centimetres.
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4
This highest difference in level and the extent of travel of the bell , serve to
determine the amount of mercury to be placed in the channel r, as well as the
height of the bell and of the walls of the channel.
When the steam pressure in the boiler falls, the water level in the vertical
pipe H will fall, thereby diminishing the pressure in the internal space G* of the
regulator. As the pressure falls, the bell will begin to move downwards very
slowly, until, if the pressure continues to fall, it finally comes again to rest upon
the bottom of the channel. By this means the air is again allowed a free passage
to the grate.
If the pressure still continues to fall,' the water level will fall below the place
where the bell is connected by an india-rubber tube with the vertical pipe H.
Then simultaneously with the fall of the water in the vertical pipe H, the india
rubber tube s', the vertical pipes with its extension e, and the interior of the
tube g, will be emptied through the lower pipe connection g³.
The object of the tubular extension e is to cause water rising within the tube g
to confine a volume of air between the top of the bell and the water surface that
will prevent contact between the water and the mercury.
Since the bell rises only when there is a pressure upon it of a of an
atmosphere, the two mercury levels will until this pressure is reached gradually
set themselves to a difference in height of 19 centimetres. The mercury forming
the inner column will sink, and the water in the tube will rise to a small extent.
But if the bell h rises, the lower end of the pipe e will also rise. The water will
then flow out of the vertical pipe and also out of the boiler and into the space
thus rendered free. But since the said space is so small compared to the whole
volume of the water, there will be no appreciable loss of pressure. The tubular
extension e is made of such a length that notwithstanding the above mentioned
rising of water in the space G, the water level can never rise to the upper edge
of the inner tube g.
The pipes, which also serves as a guide for the bell when rising, constitutes
the connection of the bell with the main vertical pipe H, and thus-causes the
same to be emptied each time the steam pressure falls sufficiently low, because
when the water falls, the air can pass after it freely into the space G*. If this
upper connection were not provided, then when the water in the vertical pipe falls
below the level in the regulator, there would be produced in the space G* a
practical vacuum which might result in the mercury passing over the top of the
inner tube y (which is not made very high for constructional reasons) into the
space G, and thus be lost. This would always take place because the water in

page_text: the vertical pipe H would have to fall to the level of the inlet opening of the
lower pipe connection before equilibrium of pressure with the outer air could
be effected by air entering by fits and starts through said lower pipe connection.
This drawback can be obviated by the use of a blind pipe, but since the water
would in such case always fill the lower part of the pipe g, and the air above the
same could therefore not be renewed, the bell would have to be made absolutely
air-tight, if the object and the action of the pipe e were not to become entirely
doubtful.
But since in practice the bell with its pipe connections can only with difficulty
be made absolutely air-tight, the arrangement as described of the bell has been
chosen, whereby the air which separates the water and the mercury in the regulator,
renewed at every great variation in pressure.
Fig. 2 shows the regulator in amplified form. In this case the pipes carries a
ring which bears against a weight g when the bell h rises. This weight g is
chosen such that at a pressure of 0-25 atmosphere it will arrest the further travel
of the bell at which pressure the bell rises exactly as in the simple regulator;
but when the pressure rises to 0.4 atmospheres, the weight will be raised until it
strikes against the cover d. The weight 9 has two arms aa which are connected
by draw rods z with a device for cutting off the air, the arrangement being such
that when the weight is raised, a passage is opened towards the flues for the
purpose of directly cooling the boiler walls by means of cold external air. Since
the valve shuts off its passage at the first upward stroke of the bell it must be
able to yield at the second stroke, and it is to this end mounted on a spring f
which balances the weight of the valve 1, but yields to any greater pressure.
This form of regulator is applicable where the composition of the fuel does not
afford the certainty when the fresh air is shut off that the generation of heat on
the grate will actually become less.
The regulator is also applicable to water heating apparatus. The space G* in
Fig. 3 is in this case provided at the bottom with an extension or widened part E
which is filled with water or any other suitable liquid. In this liquid there is
located a coiled pipe which is connected with the rising pipe or the return pipe of
the water heating apparatus.
The water expands when heated, and passes into the extension e and pipe 8
which is open at top. The expanding water thus produces a pressure column for
the bell which is necessary, as in Figs. 1 and 2, to press the bell / upwards.
The rising movement may be divided into two stages. At a certain temperature
the water level in the vertical pipes will be at such a height that the bell will
just begin to move. With a further increase of temperature the water will expand
to a greater extent, and then the bell will rise correspondingly with the increasing
volume whilst the water in the vertical pipes will always remain at the same
level. The two stages may be combined in such a manner that the given maximum
temperature of a water heating apparatus shall not be exceeded in the rising pipe
or in the return pipe, but that the air valve / will close previously.
Dated this 20th day of Octahan 1801
W. LLOYD WISE,
Per James G. Stokes,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improved Regulator for Low Pressure Heating Apparatus.
0 1, FRANZ WAGNER of Markt 5, II, Crimmitschau, Germany, Gentleman, 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 a regulator for low pressure heating apparatus in which

page_text: there is arranged a hood or bell (hereinafter called a bell) movable in an annular
channel and sealed with a liquid, the arrangement being such that the said bell
rises within a vertical pipe forming the outer wall of the annular channel, when
the water attains a certain level, and contracts or closes a passage or passages for
the admission of air to the grate of a stove by means of a closing device. An
arrangement is provided such that at a certain height of pressure water in the
vertical pipe, the bell rises until it strikes against a weight whereby its stroke is
limited for the time being and the closing device is closed, but so that when the
column of pressure water in the vertical pipe rises beyond a further limit, the
bell will raise the weight and thereby open a channel which conveys the air behind
the grate.
In the drawings left with my Provisional Specification
Figs. 1 and 1 illustrate the regulator in its simplest form. It consists of a movable
part comprising the bell h, the short_vertical pipe s, and the air valve l, and a
stationary part comprising two concentric tubes and g' that form between them
the annular channel 7. The bell his inserted within the channel and is capable of
moving vertically therein. The interior of the inner tube g is connected at its
lower end by a short pipe g with the main vertical boiler pipe H of the low pressure
boiler. The movable part of the regulator is connected with the vertical pipe H
by means of an india rubber tube s', this connection being effected by means of
the short vertical pipes in such a manner that the bell h can rise and fall
without hindrance. The regulator is connected with the vertical pipe H in such
a manner that its base is situated slightly above the highest normal boiler water
level.
The annular channel is partly filled with mercury so that between the bell h
and the stationary part of the regulator is a space (which is connected at top
and bottom only with the vertical pipe H.
The buoyancy of the bell dipping into the mercury need not be considered
with relation to the weight of the entire movable part which is such that the bell /
when in its normal state of rest, will bear upon the bottom of the channel.
The vertical pipe s has within the bell a tubular extension e the object of
which will be hereinafter explained.
The operation of the regulator is as follows:-
With increasing steam pressure in the boiler, the water will be forced into the
vertical pipe H whence it will pass through the lower connecting pipe into the
internal space G* of the regulator. Here it will rise until the water level reaches
the lower mouth of the tubular extension e. Since the space above this level is
shut off from the external atmosphere and also from the vertical pipe H, the
rising water can only take its further course through the pipe e, thereby shutting
off the space G which is full of air and the capacity of which is determined by
the length of the tubular extension c. The water will continue to rise in the
extension e and pipes and after passing through the india rubber pipe s¹, will again
unite with the water in the vertical pipe H.
It will be readily seen that when the interior of the tube 9 is filled with water
and air as described, the bell and the mercury will be subjected to the pressure
of a column of water, the height of which corresponds to the difference in height
between the plane of the top or cover of the bell and the plane of the water level
in the vertical pipe H.
This pressure will manifest itself in a twofold manner; first it will cause a
difference in level of the mercury which is enclosed between the bell h and the
tube g, as compared with the mercury column which is enclosed between the bell
and the outer tube g', this difference between the two mercury levels corresponding
to the ratio of the specific weights of water and mercury, and being 13.6 times as
small as the already mentioned difference (which produces the pressure) between
the height of the water level in H and the top of the bell. The second effect of
the pressure consists in its tendency to raise the bell h which is movable vertically.
The weight of the bell h, pipe s with extension e, and the air valve / is made such

page_text: that those parts which constitute the movable part of the regulator, will be raised
only when there is a column of water of about 2.5 metres in height in the vertical
pipe H above the lower end of the tubular extension e, at which time the air
valve will be moved nearer to the inlet of the passage for air to the fire grate,
and finally will entirely close this passage. This water column corresponds to a
pressure of about of an atmosphere in the internal space G* of the regulator.
The two mercury columns herein before mentioned will therefore then shew a
difference in level of centimetres == 19 centimetres. This highest difference in
level and the extent of travel of the bell h, serve to determine the amount of
mercury to be placed in the channel as well as the height of the bell and of the
walls of the channel.
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4
When the steam pressure in the boiler falls, the water level in the vertical
pipe H will fall, thereby diminishing the pressure in the internal space G* of the
regulator. As the pressure falls, the bell will begin to move downwards very
slowly, until, if the pressure continues to fall, it finally comes again to rest upon
the bottom of the channel. By this means the air is again allowed a free passage
to the grate.
If the pressure still continues to fall, the water level will fall below the place
where the bell is connected by the india rubber tube s with the vertical pipe H.
Then simultaneously with the fall of the water in the vertical pipe H, the india
rubber tube s', the vertical pipes with its extension e, and lastly the interior of
the tube g will be emptied through the lower pipe connection g².
The object of the tubular extension e is to cause water rising within the tube g
to confine a volume of air between the top of the bell and the water surface that
will prevent contact between the water and the mercury. Since the bell rises
only when there is a pressure upon it of about a of an atmosphere, the two
mercury levels will until this pressure is reached gradually set themselves to a
difference in height of 19 centimetres. The mercury forming the inner column
will sink and the water will rise to a small extent in the space G. But if the
bell rises, the lower end of the pipe e will also rise. The water will then flow
out of the vertical pipe and also out of the boiler and into the additional space
thus formed. But since this additional space is very small compared with the
whole volume of the water, there will be Do appreciable loss of pressure.
The tubular extension e is made of such a length that notwithstanding the above
mentioned rising of water in the space G*, the water level can never rise to the
upper edge of the inner tube g.
The pipes, which also serves to keep the bell h vertical when rising, constitutes
the connection of the bell h with the vertical pipe H, and thus causes the same to
be emptied each time the steam pressure falls sufficiently low, because when the
water falls, the air can pass after it freely into the space G*. If this upper
connection were not provided, then when the water in the vertical pipe falls below
the level in the regulator, there would be produced in the space G* a partial
vacuum which might result in the mercury passing over the top of the inner tube
(which is not made very high for constructional reasons) and into the space G*,
and thus be lost. This would take place each time the water was discharged from
the space G because the water in the vertical pipe H would have to fall to the
level of the inlet opening of the lower pipe connection 9, before equilibrium of
pressure with the outer air could be effected by air entering through the said lower
pipe connection.
This drawback can be obviated, by the use of a blind pipe, but since the water
would in such a case always be in the lower part of the pipe 9, and the air above
the same could therefore not be renewed, the bell h would have to be made
absolutely air-tight, if the object and the action of the pipe e were not to become
entirely doubtful.
But since in practice the bell with its pipe connections can only with difficulty

page_text: be made absolutely air tight, the arrangement of the bell herein before described
and shewn in the drawings has been chosen, whereby the air which separates the
water and the mercury in the regulator, is renewed at every great variation in
pressure.
Fig. 2 shews a modified construction of the regulator. In this case the pipe
carries a ring which bears against a weight g* when the bell rises to a determined
height. This weight gx is such that at a pressure of about 0-25 atmosphere it will
arrest the further travel of the bell h, at which pressure the bell rises exactly as in
the simple regulator; but when the pressure rises to 0.4 atmospheres, the weight
will be raised until it strikes against the cover d. The weight g* has two arms a a
which are connected by draw-rods with a device l' for cutting off the air, the
arrangement being such that when the weight is raised, a passage is opened towards
the flues for the purpose of directly cooling the boiler walls by means of cold
external air which enters by the said passage. Since the valve shut off its
passage at the first upward stroke of the bell, the connection between the valve
and the bell must be able to yield at the second stroke, and to this end the valve
is mounted on a spring f which balances the weight of the valve, but yields to
any greater pressure.
This form of regulator is applicable in cases where the composition of the fuel
does not afford the certainty, that when the fresh air is shut off, the generation of
heat on the grate will actually become less.
The regulator is also applicable to water-heating apparatus. The space G* in
the arrangement shewn in Fig. 3 is provided at the bottom with an extension or
widened part E which is filled with water or any other suitable liquid. In this
liquid there is located a coiled pipe which is connected with the rising pipe or the
return pipe of the water-heating apparatus.
The water expands when heated, and passes into the extension e and pipe s which
is open at top. The expanding water thus produces a pressure column on the
bell which is necessary, as in Figs. 1 and 2, to press the bell h upwards. The
rising movement may be divided into two stages. At a certain temperature the water
level in the vertical pipe s will be at such a height that the bell h will just begin to
move. With a further increase of temperature the water will expand to a greater
extent, and then the bell h will rise correspondingly with the increase in volume,
whilst the water in the vertical pipe s will always remain at the same level. The
two stages may be combined in such a manner that the given maximum temperature
of a water-heating apparatus shall not be exceeded in the rising pipe or in the
return pipe, but that the air valve will close previously.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:―
1. A regulator for low pressure heating apparatus, comprising the vertically
movable bell sealed at its lower edge, the annular chamber r containing the
sealing liquid and in which the said bell can rise and fall and the vertical pipe H
of a low pressure boiler, the arrangement being such that:-
(a) At a certain level of the water in the vertical pipe H, the bell will be
caused by the pressure of the water to rise and by means of a closing
device to contract and finally cut off the supply of air to the grate, and the
internal-space G* of the regulator will be enabled to be freely emptied
when the water level falls in the vertical pipe H substantially-a
-as described
and shewn.
2. A regulator of the kind referred to in the preceding claim, in which the bell h
will be caused to rise, (when there is a predetermined head or pressure of water in
the vertical pipe H), until it shuts the air closing device Z', and strikes against a
weight g* which limits, for the time being, its further upward travel, and when the
head or pressure of water in the vertical pipe H exceeds a further predetermined

page_text: limit, the bell will raise the weight g* and open a passage 1 by which air is
conveyed behind the firegrate of the stove substantially as described and shewn.
Dated this 19th day of March 1892.
FRANZ WAGNER,
By L. W., per F. B.