A NEW OR IMPROVED INSTRUMENT OR APPARATUS FOR ASCERTAINING AND INDICATING AT ONE OPERATION THE DENSITY, PRESSURE, AND TEMPERATURE OF STEAM."
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Lykke Boye at the Office of the
Commissioners of Patents on the 13th October 1880.
LYKKE BOYE, of Bergen, in the Kingdom of Norway, but temporarily of Paris,
in the Republic of France. "A NEW OR IMPROVED INSTRUMENT OR APPARATUS
FOR ASCERTAINING AND INDICATING AT ONE OPERATION THE DENSITY, PRESSURE,
AND TEMPERATURE OF STEAM."
This Invention relates to the construction and employment of an instrument or
apparatus for simultaneously indicating the degree of wetness or density, the pressure,
and the temperature of steam in steam engines or steam boilers, and the Invention is
based on the known fact that saturated steam is always at the maximum of
its pressure, and that super-heated steam has a less pressure than saturated steam
of the same temperature. So long as a certain volume of saturated steam contains
water, its pressure is not a function of its volume, consequently by keeping the
temperature constant the saturated steam can be expanded to a certain degree
without diminishing its pressure, but at the instant that the last particle of water
in the saturated steam is vapourized by the action of the expansion, that is to say,
at "the point of saturation" the steam will be superheated and its pressure will
diminish. In practice it is not sufficient to know only that a boiler gives steam of
a certain pressure and temperature, but it is of great importance to be able
to ascertain what kind of steam regarding its degree of wetness or density the
boiler produces when the true performance of a boiler or an engine is to be
ascertained.
In carrying out my Invention I employ a vertical cylinder fitted with a piston
and piston rod and connected to the boiler or to the steam engine; the said
cylinder is in communication with two other cylinders, in one of which is placed a
manometer or steam gauge for measuring the pressure of the steam, and in the
other cylinder I place a thermometer for ascertaining the temperature of the
steam.
When the said three cylinders are filled with saturated steam I shut off their
communication with the boiler or steam engine by means of a cock suitably
constructed for this purpose, and I allow this known volume of saturated steam to
I Prine 1

page_text: expand to a superheated condition. As the proportions between a certain volume
of the said vertical cylinder and the whole volume occupied by the saturated steam
are known at the beginning of the experiment, I can by measuring the travel of
the piston in any suitable manner shew the percentage of water which was
contained in the saturated steam. As above mentioned the instant in which the
saturated steam becomes superheated, the pressure diminishes.
It is of great
importance to have means of ascertaining this alteration of pressure however small
the change may be. The common manometer or steam gauge constructed on the
"Bourdon "principle would not shew such a slight difference in pressure as that
which takes place at the moment mentioned. Now I apply to such a manometer a
multiplying motion constructed on the same principle as those in a common watch
for shewing the minutes or seconds.