AN IMPROVED APPARATUS FOR INDICATING THE WATER LEVEL IN STEAM BOILERS
Year: 1870

page_text: LETTERS PATENT to Emile Daniel, of Bapeaume Town, near Rouen
(Seine Infericure, France), for the Invention of "AN IMPROVED
APPARATUS FOR INDICATING THE WATER LEVEL IN STEAM BOILERS."
Sealed the 4th October 1870, and dated the 7th April 1870.
PROVISIONAL SPECIFICATION left by the said Emile Daniel at the
Office of the Commissioners of Patents, with his Petition, on the
7th April 1870.
I, EMILE DANIEL, of Bapeaume Town, near Rouen (Scine Infericure),
5 France, do hereby declare the nature of the said Invention for "AN
IMPROVED APPARATUS FOR INDICATING THE WATER LEVEL IN STEAM BOILERS," to
be as follows:-
In addition to the many services which ordinary level indicators or
water gauges daily perform when applied to steam boilers there exists the
great inconvenience caused by the frequent breakage of the glass tubes,
indispensable to the apparatus however strong they may be made.
Before entering upon the nature of my Invention it will be well to
consider the cause of this breakage which so frequently takes place
without any visible cause. It is due to the sudden variations of

page_text: temperature to which the glass tubes are subjected in their interior by
the ordinary action of the indicators. The glass being a bad conductor
of heat breaks at a high temperature much more readily when thick
than when very thin, for in the former case the particles of glass are
very unequally heated and the rupture is thus caused, while in the
latter case the thin glass becomes heated much more quickly and
regularly. But the tubes required in an apparatus of this sort are always
very thick in order to be able to resist the pressure of steam and the
constant breakages are thus explained.
Now the object of my Invention is a level indicating apparatus or
water gauge which will avoid this defect, and its nature and action will
be readily understood from the following description:-It is composed
of an isolating cylinder supporting the indicating tube or water gauge
proper, which it separates from the boiler or steam generator. This
cylinder is connected to the generator by two ordinary conducting cocks,
and communicates with the lower portion of the indicating tube by a
cock mounted upon a bent pipe, and with the upper part of the same
tube by a serpentine pipe or coil, which serves as a refrigerator, and by
a straight pipe. At the bottom of the isolating cylinder a small vertical
pipe is mounted which is closed at the upper extremity, and open to
the atmosphere at its lower extremity. So arranged, the apparatus is
fitted to an empty generator, all the cocks are opened and the generator
is filled. The water rises preserving the same level in the generator
in the isolating cylinder and in the indicating tube until the desired
quantity has been reached, when the air which may be above it in the
three receptacles, is under the normal atmospheric pressure. The
generator is then closed and heat applied to it until the pressure desired
has been obtained, say, one equal to seven atmospheres. The water
preserves the same level in the three receptacles, and the steam passing
through the upper cock communicating from the generator into the
isolating cylinder fills all the space in the latter which is not occupied by
water. In order to do this it displaces the air, which it presses into the
serpentine pipe, and thence into the space above the water in the
indicating tube. This compressed air constitutes, so to speak, an elastic
cushion, which prevents the bubblings of the water in the isolating
cylinder and in the generator from being felt in the indicating tube,
which is a very appreciable advantage in practise. The water in this
tube is relatively isolated from the generator, and it is considerably
cooled through being in contact with the tube mounted, as stated above,

page_text: in the lower portion of the isolating cylinder. In this manner the
temperature of the still water in the indicating tube is always a good deal
lowered, and in consequence the liability of the latter to break is greatly
lessened. That portion of steam which is in contact with the air in the
serpentine pipe is to a considerable extent in a vesicular state bordering
upon condensation, and therefore prevents the heating of the upper
portion of the indicating tube, and forms as a separation as it were which
does not permit the mixture of air and steam.
The apparatus may be very rapidly and easily attached and detached
to and from the steam generator or other vessel to which it may be
necessary to fit it, and is of course applicable to all machines whether
fixed, locomotive, or otherwise.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Emile Daniel in the Great Seal Patent Office on
the 5th October 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EMILE
DANIEL, of Bapeaume Town, near Rouen (Seine Inferieure), France,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of April, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Emile Daniel, Her special licence that I, the
said Emile Daniel, my executors, administrators, and assigns, or such
others as I, the said Emile Daniel, executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "AN IMPROVED APPARATUS FOR INDICATING
THE WATER LEVEL IN STEAM BOILERS," upon the condition (amongst others)
that I, the said Emile Daniel, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
scals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed and

page_text: cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Emile Daniel, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the Drawings here-
unto annexed, that is to say:-
The many services which ordinary level indicators or water gauges
daily perform when applied to steam boilers are rendered less valuable
by the great inconvenience caused by the frequent breaking of the glass
tubes indispensable to these apparatus.
Before entering upon the nature of my Invention it will be well to
consider the cause of this breakage which so frequently takes place
without any visible cause. It is due to the sudden variation of temperature
to which the glass tubes are subjected in their interior by the ordinary
action of the indicators. The glass being a bad conductor of heat breaks
at a high temperature much more readily when thick than when very
thin, for in the former case the particles of glass are very unequally
heated, and the rupture is thus caused, while in the latter case the thin
glass becomes heated much more equally and regularly; but the tubes
required in an apparatus of this sort are always very thick in order
to be able to resist the pressure of steam, and the constant breakages are
thus explained.
Now the object of my Invention is a level indicating apparatus or
water gauge which will avoid this defect, and its nature and action will
be readily understood from the following description, and the accom-
panying Drawings, in which Figure 1 is a sectional elevation, and
Figure 2 a transverse section of the apparatus; it is composed of an
isolating cylinder a supporting the indicating tube or water gauge
proper b, which it separates from the boiler or steam generator X. This
cylinder a is connected to the generator by two ordinary conducting
cocks d, f, and communicates with the lower portion of the indicating
tube 6 by a cock y mounted upon the bent or angle pipe h, and with the
upper part of the same tube by a serpentine pipe c, which serves as a
refrigerator, and by a straight pipe j. At the bottom of the isolating
cylinder a a small vertical pipe i is secured, which is closed at the upper
extremity, and is open to the atmosphere at its lower extremity. The

page_text: cock may be placed at the shoulder of the angle pipe h, as shown in
dotted lines in Figure 1. In this case the plug of the cock 7 would by
its particular action, see Figures 3, 4, and 5, effect the filling and
emptying movements from both pipes according to the way in which it
was turned.
In Figure 3 the plug is shewn as turned on in order to establish the
communication between the tube band the cylinder c during the ordinary
action of the apparatus. So arranged the apparatus is fitted to an empty
generator, all the cocks are opened, and the generator is filled. The
water rises, preserving the same level in the generator, in the isolating
cylinder a, and in the indicating tube b, until the desired quantity has
been reached, when the air which may be above it in the three
receptacles is under the normal atmospheric pressure. The generator is
then closed and heat applied to it until the pressure desired has been
obtained, say, one equal to seven atmospheres. The water preserves the
same level in the three receptacles, and the steam passing through the
upper cock d communicating from the generator into the isolating
cylinder a fills all the space in the latter which is not occupied by water.
In order to do this it displaces the air which it presses into the serpen-
tine pipe c, and thence into the space above the water in the indicating
tube d. This compressed air constitutes, so to speak, an elastic cushion,
which prevents the bubblings of the water in the isolating cylinder a and
in the generator from being felt in the indicating tube b, which is a very
appreciable advantage in practice. The water in the tube b is relatively
isolated from the generator, and it is considerably cooled through being
in contact with the tube i mounted, as stated above, in the lower portion
of the isolating cylinder a. In this manner the temperature of the still
water in the indicating tube is always a good deal lowered, and in
consequence the liability of the latter to break is greatly lessened. That
portion of steam which is in contact with the air in the serpentine pipe
is to a considerable extent in a vesicular state bordering upon con-
densation, and therefore prevents the heating of the upper portion of the
indicating tube, and forms a barrier as it were, which does not permit
the mixture of air and steam.
This apparatus may be very rapidly and easily attached and detached
to and from the steam generator or other vessel to which it may be
necessary to fit it, and is of course applicable to all machines, whether
fixed, locomotive, or otherwise.

page_text: I have shewn in dotted lines in Figure 1 three cocks o, o¹, o², which
I especially apply to locomotives or to tubular boilers generally. These
cocks fulfil no function during the ordinary working of the apparatus,
but they are indispensable when the glass tube happens to break and
cannot be immediately replaced.
In relation to these cocks it becomes necessary, as will be readily
understood, to fit a cock N (shewn in dotted lines in Figure 1) between
the top of the cylinder a and the serpentine pipe c.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim,-
First. The arrangement between the indicating tube and the boiler of
an isolating cylinder, such as that described and shewn.
Secondly. Placing at the bottom of this isolating cylinder a refriger-
ating pipe i, which constantly exerts a cooling influence upon the
water in the cylinder.
Thirdly. Adapting to the upper part of the cylinder a a serpentine
pipe communicating at its other end with the top of the indicating
tube.
And, fourthly. The general construction and arrangement of my
apparatus for indicating the water level in steam boilers, substantially as
described and shewn in the accompanying Drawings.
In witness whereof, I, the said Emile Daniel, have hereunto set my
hand and seal, this Tenth day of September One thousand eight
hundred and seventy.
Witness,
C. LAFOND,
Civil Engineer,
23, Boulevart de Strasbourg,
à Paris.
EMILE DANIEL. (L.S.)