Improved Method of, and Means or Apparatus for, Indicating and Recording the Presence of Air in Steam, applicable also for Esti- mating the Pressure of Saturated Steam Free from Air, and the Rate of Generation and Temperature of Steam.
Year: 1897

page_text: Date of Application, 2nd Nov., 1897
Complete Specification Left, 2nd Sept., 1898-Accepted, 2nd Nov., 1898
Improved Method of, and Means or Apparatus for, Indicating and
Recording the Presence of Air in Steam, applicable also for Esti-
mating the Pressure of Saturated Steam Free from Air, and the
Rate of Generation and Temperature of Steam.
I, SHERIDAN DELÉPINE of Owen's College, in the City of Manchester, Bachelor
of Medicine, Master of Surgery, Bachelor of Science, Professor of Pathology, etc.,
do hereby declare the nature of this invention to be as follows:-
When using steam for various purposes, it is often desirable to be able to ascer-
tain what amount of air remains in the generator, also when the air has been
expelled, and my invention has for object to enable this to be done in a con-
venient and efficient way.
It is known that, if a channel be in sufficiently free communication with a
steam generator, the proportion of air to steam will be sensibly the same in such
channel as in the steam generator itself, and, according to my invention, this is
taken advantage of. It is also known that when pure steam is cooled sufficiently
it returns to the liquid state so that from a mixture of steam and air, it is pos-
sible to separate the air by condensing the steam.
For this purpose, to the steam generator, or to' some pipe or passage or chamber
in communication therewith, I connect a tube or receptacle (hereinafter called
the tube or reservoir) adapted to be automatically or otherwise disconnected at any
time from the steam generator, and provide for condensation of samples of the
steam and for affording an indication of the quantity of residual air (if any).
Apparatus for this purpose, according to my invention, may be variously con-
structed.
In one arrangement, the tube or reservoir is connected with a vessel containing
water or other suitable liquid, in such a way that, on arrestation of the supply
of steam to the tube or reservoir, steam which it then already contains will be
condensed, thereby forming a partial vacuum, and causing water to occupy space
just previously occupied by steam, and trapping any residual air. The tube or
reservoir is or may be made wholly or partially of transparent material, such as
glass, or otherwise adapted (it may be by sight holes or tubes) to enable the pro-
portion of air retained to be read off. Or the amount of air remaining in the tube
may be estimated indirectly by noting the weight of water which has passed into
the tube to replace the steam which has condensed. To enable this to be done the
vessel containing the water may be supported by one arm of a lever, the other arm
of which is arranged to indicate, or it may be to record upon a drum or the like,
the changes of weight of the water in the vessel. In such an arrangement means
are provided to ensure that, whenever the tube is occupied by steam or a mixture
of steam and air the water level in the vessel shall be the same. Suitable means
such as a parallel motion may be provided to maintain the water vessel in a
vertical attitude.

page_text: According to another arrangement, in lieu of effecting condensation by direct
application of water, I provide the tube or reservoir (which may advantageously
be of cylindrical form) with a jacket adapted to contain cold fluid, and in which
cold fluid may circulate, and provide a piston adapted to be driven towards one
end of the tube or reservoir as condensation takes place, but to reach the end of
its stroke only when the whole of the air has been expelled from the tube or
reservoir.
In cases where it is desired with such an apparatus to record when the whole
or a given part of the air has been expelled, I sometimes provide, in connection
with the piston, suitable gear so arranged as to be controlled by the piston, and,
at the proper time, to be caused to operate so as to give the required indication.
Thus a rod connected with the piston may be provided with a rod fitted with a
pen, pencil or other writing instrument held in contact with the surface of a
moving drum or sheet of paper, metal or any other suitable material. The move-
ments of the piston may if desired be reduced or amplified by means of a lever
connected at one end with the piston and at the other end with the writing
arrangement. The movements of the piston may also be recorded by photography
or by means of electrical contacts as may be deemed most expedient for the pur-
pose in view.
•
.
The disconnection between the tube or reservoir and the steam generator may
be effected by any suitable means, such as a valve or cock, and means may be
provided whereby the disconnection may be effected automatically at the required
times, said means being adapted to be operated by the action of the steam itself,
by clock work or by other mechanical contrivance, or by suitable electrical
mechanism. Sometimes I provide means whereby the steam is, at intervals, ad-
mitted to a by-pass containing apparatus according to my invention.
I sometimes provide special means for cooling the tube or reservoir, as, for
instance, in the event of radiation being insufficient for the purpose.
Another arrangement of apparatus, according to my invention, is as follows:-
The tube or reservoir opens into a vessel adapted to contain suitable liquid,
such as water, provision being made for keeping such water at a sufficiently low
temperature.
For this purpose, the vessel may be provided with a jacket in which cooling
fluid is caused to circulate, or with a coil or coils, or with other known or suitable
cooling means.
In one arrangement the tube or reservoir opens within the water vessel below a
bell supported by one arm of a lever. As the air mixed with the steam escapes
from the tube or reservoir it is trapped in the bell from which it can escape only
when it is in sufficient amount to overcome the pressure of a suitably arranged
valve or short column of liquid. As air accumulates in the bell, the bell rises in
the water, and at the same time raises the lever arm to which it is connected, thus
depressing through an equal angle the other arm of the lever which is connected
with suitable recording apparatus, adapted to trace the movements of the bell.
When the pressure of the air is sufficient to open the valve or overcome the pres-
sure of the water column and permit the air to escape, the bell descends; accu-
mulation of air again raises the bell and so on until all the air has been expelled
from the steam generator, when the bell will resume its original position.
bell may be provided with an upward tubular extension to the upper end of
which the valve is fitted. In an arrangement of this kind the valve or water
column may be dispensed with the air being trapped in the bell and not allowed to
escape so that the escape of pure steam will be indicated by the ceasing to ascend
further. In such a case only a very small amount of steam is allowed to pass into
the apparatus.
The
In another arrangement the orifice of the tube or reservoir is so located as to
be below water level, and there is provided a valve which may be of light sheet
metal carried by a lever arm able to move about an axis in such wise that in one
of its positions the orifice of the tube or reservoir will be closed by the valve;

page_text: to the said lever arm a second lever arm is so connected that when the first lever
arm is moved about its axis or fulcrum the second lever arm will be moved through
like angle. By means of the second lever arm vibrations of the first lever arm
are in some suitable way recorded on a moving surface, as well understood.
With such an arrangement, when steam free from air escapes from the tube
or reservoir into the liquid-containing vessel and condensation takes place, the
valve will close against the orifice of the tube or reservoir. As a partial vacuum
follows condensation whenever it takes place and as when a stream of steam is
made to pass through cold water intermittent condensation will take place at the
orifice of the steam tube, it results that short waves of expansion and condensa-
tion will be produced, which will cause corresponding vibrations or movements
of the lever arms, so that, in practice, they will commonly, that is to say when
steam is escaping, make very rapid and short vibrations at or near a position cor-
responding to the closed position of the valve the record being made near the
zero line of the moving surface, whereas their movements will be through larger
angles and the record will be made at a greater distance from the zero line when
air escapes.
In order to facilitate the reading of the record, the levers may be so weighted
that the rapid and short vibrations will not be indicated but only the mean posi-
tion occupied by the levers at any given period; the record will then be made by
a comparatively even line rising and falling according to whether pure steam or
a mixture of air and steam be escaping from the tube.
These respective vibrations or movements are or can be recorded, as already
stated, on a moving surface, and in this way a continuous diagram or tracing can
be obtained, indicating the presence at any moment of air or steam within the
boiler or steam chamber that is in connection with the apparatus.
It is to be noted that, although I have thus indicated several constructions
which may be conveniently adopted in carrying out my invention, yet they are
susceptible of modification and adaptation to particular requirements, and that
arrangements other than those above more particularly set forth may be provided
with means for recording diagrammatically or otherwise the indications from time
to time afforded by the apparatus.
It will be seen that some of the arrangements hereinbefore described may be
employed to indicate the exact amount of air present in the steam whereas others
merely indicate whether the steam is free from air or not.
Amongst the numerous purposes to which my invention in one or other of its
forms may be applied is that of indicating the presence of air in steam used in
disinfecting apparatus. Or it may be applied to automatically regulate the heat-
The method and
ing of a steam generator or the escape of steam from the same.
apparatus herein before described may also be used for determining (1) the pres-
sure of saturated steam free from air: (2) the rate of generation of steam in
function of pressure and of the size of the steam outlet and (3) the temperature of
steam or mixture of steam and air in function of pressure.
(1). The determination of pressure is obtained empirically by measuring the
pressure of steam in the steam generator by one of the well known methods and
measuring at the same time the amplitude of the vibrations of the lever recording
the wave produced by the intermittent condensation of the steam. For a given
size of the opening through which the steam escapes, the amplitude of the vibra-
tions is found to be proportional to the pressure under which the steam escapes;
the proportion may have to be determined for each form of apparatus used.
(2). The rate of generation of steam is determined by the rapidity with which
air escapes from a boiler at a given pressure. I have found experimentally that
there is a critical escape of air as soon as the temperature of the water is within
a few degrees of the boiling point; from that moment, which is indicated by a
characteristic appearance of the curve, the air is expelled from the boiler at a
rate which depends on the rapidity with which steam is generated, that is to say,
with an outlet of a given size, the quicker the steam is generated the quicker the

page_text: lever will indicate complete expulsion of air, so that it is possible to prepare
empirically tables showing for each pressure and size of outlet, the rate of genera-
tion of steam.
(3). I have found by experiments that at the ordinary atmospheric pressure, the
critical escape of air takes place just before the boiling point, and that when the
lever indicates escape of steam free from air, the temperature is invariably that of
the boiling water at atmospheric pressure. For higher pressures the problem is
more complicated and the temperature will depend on whether the pressure valve
is closed before air has escaped from the boiler, or is made to act only after all, the
air has been expelled; here again by empirical determination tables may be pre-
pared.
Improved Method of, and Means or Apparatus for, Indicating and
Recording the Presence of Air in Steam, applicable also for Esti-
mating the Pressure of Saturated Steam Free from Air, and the
Rate of Generation and Temperature of Steam.
I, SHERIDAN DELEPINE, of Owens College, in the City of Manchester, Bachelor
of Medicine, Master of Surgery, Bachelor of Science, Professor of Pathology, etc.,
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:
When using steam for various purposes, it is often desirable to be able to ascer-
tain, without interrupting the generation of steam, what amount of air remains in
the generator, also the time or moment when the air has been expelled, and my
invention has for object to enable this to be done in a convenient and efficient
way.
If a channel be in sufficiently free communication with a vapour or steam gene-
rator, the proportion of air to steam will be sensibly the same in such channel
as in the steam generator itself when enough steam is generated to produce a free
current in the generator and channel connected with it; according to my inven-
tion, this is taken advantage of. When pure steam is cooled sufficiently, it returns
to the liquid state, so that from a mixture of steam and air, it is possible to
separate the air by condensing the steam.
For this purpose, to the steam generator, or to some pipe or passage or chamber
in communication therewith, I connect a tube, receptacle or reservoir adapted to
be automatically or otherwise disconnected at any time from the steam generator,
and provide for condensation of samples of the steam and for affording an indica-
tion of the quantity of residual air (if any).
Apparatus for this purpose, according to my invention, may be variously con-
structed.
The accompanying drawings illustrate by way of example some forms of such
apparatus. Referring to Fig. 1, 1 is a tube through which steam from a generator
or other steam vessel can flow in the direction of the arrows; it is connected by
means of a tubular extension 1" with a vessel 2 containing water or other suitable
liquid. The tube 1 is provided with two taps 1* that are formed in one and are so

page_text: arranged as to simultaneously cut off the supply of steam to the tube 1 and to
close the exit from said tube. The steam it then contains will be condensed, a
partial vacuum formed, water caused to occupy space just previously occupied by
steam, and any residual air trapped.
The amount of air remaining in the tube 1 may be estimated indirectly by
noting the weight of water which has passed into the said tube to replace the
steam which has condensed. To enable this to be readily done, the vessel 2 may,
in some cases, be supported by one arm of a lever 3, the other arm of which is
fitted with a writing instrument adapted to record upon a rotating drum 4 changes
of weight of the water in the vessel 2. The recording arm of the lever is shown
provided with a weight 5, which can be adjusted so as to balance the lever when
the water level therein is normal. A tension spring 6 may be arranged to come
into operation as a spring-balance when the recording arm overbalances that sup-
porting the vessel 2.
An overflow is provided to get rid of the water of conden-
sation and thus ensure that, whenever the tube is occupied by steam or a nixture
of steam and air, the water level in the vessel shall be the same.
When continuous records are wanted the taps 1* are connected with a suitable
motor, adapted to cause a complete revolution of the said taps at regular intervals.
I have used and found suitable clock work (moved by a weight or strong spring);
the same motor may be used for driving the drum 4.
The lever 3 may be provided with a pointer working over an index instead of
being arranged to give a permanent record. Suitable means, such as a parallel
motion may be provided to maintain the water vessel in a vertical attitude, if
required.
Fig. 2 illustrates a modified arrangement of apparatus, according to my inven-
tion in which a tube I in communication with the steam generator or other cham-
ber opens into a vessel 2 containing suitable liquid, such as water, which may be
kept at a sufficiently low temperature by means of cooling fluid circulating
through a jacket or a coil or coils, or by other suitable means. The tube 1 which
may be fitted with a pressure regulating valve 1b, discharges through a small
outlet orifice into the water vessel below a bell 9 supported by a lever 3 attached
to one end of a spring 3 the other end of which is fixed at 3b as shown. As air
mixed with steam escapes from the tube 1 the steam is condensed and the air is
trapped in the bell, from which it can escape through a small aperture 9" only
when it is in sufficient amount to overcome the pressure of a short column of
liquid above the aperture of and the friction between the said aperture and the
bubbles of air which act after the manner of valves. The size of the opening "
is determined by the size of the tube 1, and the rapidity with which the steam
generator is heated. In the form shown in Fig. 2, which is drawn full size, the
outlet of tube 9 should preferably not exceed 3/16 inch and the opening 9" 1/30 inch
in diameter; but by taking advantage of valve 1b and altering the height of the
water in the vessel 2 other proportions will work well, As air accumulates
within the bell, the bell rises in the water, and, at the same time, raises the
lever 3 which is fitted with a writing instrument adapted to trace the movements
of the bell on a drum 4. When the pressure of the air is sufficient to overcome
the pressure of the water column and permit the air to escape, the bell descends;
accumulation of air again raises the bell and so on until all the air has been
expelled from the steam generator, when the bell will resume its original position.
This process is described as if it took place slowly for the purpose of clearness
but as a matter of fact the escape of air bubbles takes place almost continuously,
causing only slight oscillation of the lever which is kept partly raised so long as
air escapes. The aperture 9 may be controlled by a valve and the bell may have
in communication with it through the aperture 9" an upward tubular extension,
to the upper end of which the valve is fitted.
In an arrangement of this kind both the valve and water column may be dis-
pensed with, the air then being trapped in the bell and not allowed to escape, so
that the escape of pure steam will be indicated by the bell ceasing to ascend

page_text: further. In such a case only a very small amount of steam is allowed to pass into
the apparatus.
Fig. 3 is a sectional elevation of another arrangement in one form of which the
small outlet orifice of a tube 1 is so located as to be below the level of the water
in th vessel 2 and is provided with a valve 10, which may be of light sheet metal,
carried by one arm of a bell crank lever 3 able to move about an axis in such
wise that in one of its positions the orifice of the tube 1 will be closed by the
valve; the other arm of the lever carries a writing instrument by means of which
its vibrations are recorded on a moving drum or surface 4, as well understood.
With arrangements such as shown in Figs. 2 and 3, when steam free from air
escapes from the tube 1 into the liquid-containing vessel 2 and condensation takes
place, the valve will close against the orifice of the tube. As a vacuum follows
condensation whenever it takes place, and as, when a stream of steam is made to
pass through cold water, intermittent condensation will take place at the orifice
of the steam tube, it results that short waves of expansion and condensation will
be produced, which will cause corresponding vibrations or movements of the
lever 3 so that, in practice, they will commonly, that is to say, when steam is
escaping, make very rapid and short vibrations at or near a position
corresponding to the closed position of the valve 10, the record being made near
the zero line of the moving surface, whereas their movements will be through
larger angles and the record will be made at a greater distance from the zero line,
when air escapes.
In order to simplify the record, the lever may be so weighted that the rapid and
short vibrations will not be indicated but only the mean position occupied by the
levers at any given period; the record will then be made by a comparatively even
line rising and falling according to whether, pure steam or a mixture of air and
steam be escaping from the tube.
These respective vibrations or movements are recorded on a moving drum or
surface 4, and, in this way, a continuous diagram or tracing can be obtained,
indicating the presence, at any moment, of air or steam, within the boiler or steam
chamber that is in connection with the apparatus.
The vibration, produced by the escaping steam will, cease as soon as steam
ceases to be generated with sufficient rapidity to keep up the necessary pressure
within the boiler, or, when steam is being generated, it is allowed to escape acci-
dentally or otherwise through any opening large enough to reduce the pressure
within the boiler, or steam chamber connected there with, below the pressure
to which the apparatus has been adjusted. In this way the record may be used
to show when and how long steam free from air and under certain conditions of
pressure has been acting in a boiler or steam chamber connected therewith.
My improved method and apparatus may be employed for detecting the presence
of air in vapours other than steam.
It is to be noted that, although I have thus indicated several constructions which
may be conveniently adopted in carrying out my invention, yet, they are sus-
ceptible of modification and adaptation to particular requirements, and that
arrangements other than those above more particularly set forth may be provided
with means for recording diagrammatically or otherwise the indications from time
to time afforded by the apparatus.
For instance a tube 1 such as is shown in Fig. 1 may be employed in conjunc-
tion with a fixed vessel 2 to indicate the quantity of air present in a sample of
steam or vapour.
The tube 1 is then made wholly or partly of glass or the like
so that the height to which the water rises therein may be seen and to thus enable
the proportion of air retained to be read off. Or the tube 1 may be of inverted
U-form and fitted with a vacuum gauge so that the proportion of air retained
may be ascertained from the decrease of pressure produced by condensation.
According to another arrangement, the tube 1 is replaced by a cylindrical
vessel that contains the mixture of air and steam, or pure steam, which is fitted
with a piston. On condensation of the steam, the displacement of the piston will

page_text: indicate the proportion of steam and air present. The movements of the piston
may be recorded by one of the well known methods. In any of the arrangements
described the cooling of the vessel containing the mixture may be effected in
various ways, e.g. by using a cold water jacket, or by simply taking advantage of
the difference of temperature between the external air and steam and allowing
cooling to take place by loss of heat through the walls of the vessel the surface
of which may be increased to accelerate radiation.
It will be seen that some of the arrangements hereinbefore described may be
employed to indicate the exact amount of air present in the steam whereas others
merely indicate whether the steam is free from air or not. The mechanical
designs described as examples of the application of my method may be used com-
bined together in various ways. The displacement of water by air and the con-
densation of steam might take place in distinct vessels.
Amongst the numerous purposes to which my invention in one or other of its
forms may be applied is that of indicating the presence of air in steam, used in
disinfecting or other apparatus in which it is necessary to use steam free from air.
By means of diagrams or tracings continuously produced by my apparatus it is
possible to ascertain whether machines such as disinfectors have been properly
worked; for instance from the diagrams or tracings it can be determined when
and for how long steam free from air has acted in a machine to which the appa-
ratus is applied. Or it may be applied to automatically regulate the escape of
steam from a steam generator. For this purpose the lever 3 (Fig. 2) may be so
arranged that when raised it will close an electric circuit in which is included an
electro-magnet which will cause the opening of the safety valve of the generator.
The circuit would be closed when air escaped abundantly, in which case the safety
valve would be opened and air allowed to escape freely, and also when, owing to
excessive pressure, steam escapes into the chamber 9 so rapidly that the usual
current of cold water would be insufficient to cause its complete condensation, in
which case the safety valve would also be opened and the pressure in the generator
thus reduced.
The apparatus may also be employed to regulate the heating of a generator, the
lever 3 then being arranged to close the circuit of an electro-magnet adapted to
operate a damper or the like instead of a safety valve.
The method and apparatus herein before described may also be used for deter-
mining (1) the pressure of saturated steam free from air; (2) the rate of genera-
tion of steam in function of pressure and of the size of the steam outlet and (3)
the temperature of steam or mixture of steam and air in function of pressure.
(1) The determination of pressure is obtained empirically by measuring the
pressure of steam in the steam generator by one of the well known methods and
measuring at the same time the amplitude of the vibrations of the lever recording
the wave produced by the intermittent condensation of the steam. For a given
size of the opening through which the steam escapes, the amplitude of the vibra-
ions is found to be proportional to the pressure under which the steam escapes;
the proportion may have to be determined for each form of apparatus used.
(2) The rate of generation of steam is determined by the rapidity with which
air escapes from a boiler at a given pressure. There is a critical escape of air as
soon as the temperature of the water is within a few degrees of the boiling point;
from that moment, which is indicated by a characteristic appearance of the curve,
the air is expelled from the boiler at a rate which depends on the rapidity with
which steam is generated, that is to say, with an outlet of a given size, the quicker
the steam is generated the quicker the lever will indicate complete expulsion of
air, so that it is possible to prepare empirically tables showing for each pressure and
size of outlet, the rate of generation of steam.
For
(3) I have found that when the lever indicates escape of steam free from air, the
temperature is invariably that of boiling water at atmospheric pressure.
higher pressures the problem is more complicated and the temperature will depend
on whether the pressure valve is closed before air has escaped from the boiler, or

page_text: is made to act only after all the air has been expelled; here again by empirical
determination tables may be prepared.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I cla in is;-
1. The herein before described method of indicating the presence of air in steam
contained in a generator or other chamber according to which a current of steam
is diverted therefrom, condensed, and the proportion of residual air caused to
afford the required indication substantially as set forth.
2. For indicating or recording the presence of air in steam in the manner re-
ferred to apparatus comprising a tube or the like communicating with a steam
chamber, means whereby steam in said tube or the like is caused to condense and
means for indicating or recording of the quantity of residual air, substantially as
described.
3. Means or apparatus for affording an indication of the presence of air in
steam substantially as described with reference to and shown in Fig. 1, in Fig. 2,
and in Fig. 3, of the accompanying illustrative drawings.
κουρικο
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.