A NEW OR IMPROVED INSTRUMENT OR APPARATUS FOR ASCERTAINING AND INDICATING AT ONE OPERATION THE DENSITY AND PRESSURE OF STEAM
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Lykke Boye and Ernst Müller at the
Office of the Commissioners of Patents on the 5th March 1881.
LYKKE BOYE, of Bergen, Norway, but temporarily of Dresden, in the Kingdom
of Saxony, Engineer, and ERNST MÜLLER, of Chrimmitschan, in the Kingdom of
Saxony. "A NEW OR IMPROVED INSTRUMENT OR APPARATUS FOR ASCERTAINING
AND INDICATING AT ONE OPERATION THE DENSITY AND PRESSURE OF STEAM."
This Invention relates to means and apparatus for ascertaining and indicating
at one operation the density and pressure of steam.
The percentage of weight of water contained in steam may be directly ascertained
from the fact that the volume of a certain weight of water is less than its volume
in a vapourized condition, that saturated steam is always at the maximum of its
pressure, and that if a certain volume of saturated steam expands under a constant
temperature until it becomes superheated, the instant at which it becomes super-
heated is indicated by the decrease of the pressure of the steam in this condition,
so that the volume of the steam before and after its expansion to the moment of
it attaining the superheated condition can be observed.
Now if steam be contained in a cylinder or receiver in a known volume, and a
piston be placed in this receiver in which the piston can be moved by any suitable
means which will also record the travel of the piston, and if the said receiver be
surrounded by a jacket and a continuous circulation of steam (equal in pressure or
temperature to that in the receiver) be kept up in the space between the receiver
and the jacket, the piston may be moved so as to increase the space in the receiver,
so that the expansion of the steam from a saturated to a superheated condition
takes place by the transmission of heat from the intervening space to the receiver
in such a manner that the temperature of the expanding steam shall be constant.
If now the receiver and the said space between the jacket and the receiver be put
into communication by means of a mercury-gauge or other suitable or equivalent
means, so that one end of the gauge shall correspond with the receiver, and the
other end with said space, the variation in pressure between them at the moment
at which the steam in the receiver becomes superheated through its expansion can
be ascertained from the movement of the mercury in the gauge. To prevent
מ

page_text: refrigeration and the passage of steam between the piston and the cylinder in
which it is moving, steam is admitted above the piston through a cylinder cover
which is in connection with the jacketted space. Thus the receiver being heated
all round by steam of a temperature equal to that which is being tested there will
be no difficulty in keeping the piston tight.
To allow of the density of the steam being read off, the piston is provided with
a hollow piston-rod in which works a screwed spindle, the pitch of the screw being
such that by a complete turn the piston is moved through a space which will
increase the space in the receiver one per cent. The circumference of the wheel on
the spindle is divided into one hundred parts, so that by the aid of a hand or
pointer the hundredth part of a turn, or the hundredth part of one per cent. of the
space in the receiver, may be read off. The piston is then drawn back until the
mercury gauge indicates a variation in the pressure in the receiver and the travel of
the piston, videlicet, the percentage of water in the steam may be directly read off.
By putting a manometer or steam gauge in communication with the jacketted
space the steam pressure can be ascertained.
The connection and disconnection between the receiver and the jacketted space
and the boiler steam is effected by means of a cock having an arrangement of
passages such that in one position the cock will allow communication between the
receiver and the jacketted space and the boiler, and in another position it will only
allow a steam circulation in the jacketted space while the steam in the cylinder is
being tested, and by turning the cock about forty five degrees it will shut off
communication between the receiver and the jacketted space and the boiler. To
avoid at the commencement of the operation a condensation of steam in the
receiver it is necessary to admit steam to the jacketted space only, and the receiver;
which is filled with air, is in this manner heated up to the steam temperature, and
thus dried. The air, which is heavier than steam of the same temperature, will by
a suitable connection rush into the boiler and allow the receiver to be filled with
steam.