IMPROVEMENTS IN WATER FEEDING APPARATUS FOR BOILERS
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Alexandre Virollet at the Office
of the Commissioners of Patents, with his Petition, on the 28th
July 1871. A communication from Joseph Duché, residing at
the Coteau of Roanne (Loire), France.
I, ALEXANDRE VIROLLET, of Lubières, near Ste. Florine, Haute Loire,
France, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN
WATER FEEDING APPARATUS FOR BOILERS," to be as
follows:-
This Invention consists in the employment in connection with the
boiler of a tube provided with a chamber, in which works horizontally
a slide box, which establishes or interrupts the communication between
the boiler and the water reservoir. This slide box has two compart-
ments which alternately take water from the feed pipe and empty it into
the tube chamber. The water being thus brought into a medium which
is precisely that of the boiler tends forcibly to find its level by virtue of
the principle of communicating vessels. The immediate effect of this
action is to bring the water level in the boiler to the prescribed height

page_text: maintained.
The essential feature of this Invention therefore consists in the
employment of a slide box having two compartments acting alternately
and moving horizontally in a chamber in a tube in communication with
the boiler.
The apparatus, which may be placed near to or at a distance from the
boiler, provided its height corresponds with the water level to be
maintained, is constructed as follows:-A cast-iron box or chamber
closed by a cover communicates by tubes with the top and bottom of the
boiler to be fed. A distributing slide box in this chamber is fixed to a
rod which traverses a stuffing box, and which imparts to it a to-and-fro
horizontal motion received from a slide and crank pin or otherwise.
The slide box contains two compartments, having orifices which are
presented alternately opposite three ports formed in a fixed plate
attached to the cover. The central port of these three is the feed port
being in communication with the reservoir by means of a pipe led
through the cover, while the other two ports alternately give passage to
the water which has been received by the two compartments. A small
gauge is attached to the apparatus to show if it is working properly.
The action is as follows:-In the to-and-fro movement of the slide box
the two compartments are presented successively opposite the feed port.
If the water level in the boiler is lowered, each compartment being
empty or nearly so when it passes, the feed port becomes filled with
water, and afterwards empties this water into the chamber. While
one compartment is being filled under the pressure of the surrounding.
atmosphere the other compartment filled previously is submitted to the
same pressure as that existing in the boiler; a fresh equilibrium is thus
established by virtue of the principle of communicating vessels, and the
water in this compartment therefore raises the level at once in the
chamber and in the boiler. It will readily be understood that if the
level in the boiler is not lowered the compartments will be already full
of water when presented to the feed, and there will therefore be no fresh
introduction of water. The feed thus regulates itself in the apparatus,
the compartments taking cold water from the reservoir and expelling
hot water from the boiler according as the level in the latter is above
or below its normal position.

page_text: The apparatus may be made self-acting by utilizing the return hot
water or steam which is produced by the compartments, and by
employing the fluid thus expelled to actuate the piston of a small
accessory cylinder connected with the slide box, which will have the
advantage of regulating at the same time the speed of working.