IMPROVEMENTS IN STEAM BOILERS TO PREVENT THEIR PRIMING
Year: 1875

page_text: LETTERS PATENT to Martyn John Roberts, of the City of Bath,
Esquire, for the Invention of "IMPROVEMENTS IN STEAM BOILERS TO
PREVENT THEIR PRIMING."
Sealed the 2nd May 1876, and dated the 4th November 1875.
PROVISIONAL SPECIFICATION left by the said Martyn John Roberts
at the Office of the Commissioners of Patents, with his Petition,
on the 4th November 1875.
I, MARTYN JOHN ROBERTS, of the City of Bath, Esquire, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN STEAM
BOILERS TO PREVENT THEIR PRIMING," to be as follows:-
My Invention has for object the prevention of "priming" in steam
boilers. Many attempts have been made to overcome this evil, such for
example as leading the steam through tortuous passages on its way
from the boiler to the engine cylinder, but none of them have been
successful, because the velocity with which the water and scum or ḍirt

page_text: are raised with the steam is not sufficient to give them the requisite
inertia to separate them from the steam.
Now according to my Invention I give the requisite velocity and
inertia to the water and scum or dirt artificially. I pass the steam,
water, and scum or dirt which rise from the boiler through an apparatus
somewhat similar to a centrifugal drying machine, which revolving
thereby gives a centrifugal force to all vapour, liquid, or solid matter
that may enter it, and the water and scum or dirt being so very many
times heavier than the steam their centrifugal force will be so many
times greater than that of the steam, so that if there be apertures for a
tangential escape the water and scum will effectually separate themselves
from the steam.
The manner in which my Invention may be carried into effect is as
follows: Upon the top of the boiler I fix a dome or case, to the top of
which I connect the steam pipe leading to the cylinders. Within this
dome I place a circular box, which is made to revolve with great
velocity by means of a spindle driven by the engine. A portion of the
circumference of this box is open, and near the top of the box is a
concentric horizontal partition, the diameter of which is less than that
of the box. The box is also provided with radial partitions to ensure an
angular motion to the steam, water, and dirt. The bottom of the box
communicates at its centre with the steam space in the boiler, and the
top communicates at its centre with the steam pipe. The steam and
the water and dirt which it may carry with it enter the bottom of the
rapidly revolving box and acquire great centrifugal force before they
reach the outer edge of the horizontal partition. The steam from this
point rushes to the cylinders, where there is a minus pressure compared
with the boiler pressure, while the water and dirt are ejected through
the open portion of the circumference of the box and return to the
boiler.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Martyn John Roberts in the Great Seal Patent
Office on the 4th May 1876.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of November, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Martyn John Roberts, Her special licence,
that I, the said Martyn John Roberts, my executors, administrators,
and assigns, or such others as I, the said Martyn John Roberts, my
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 "IMPROVEMENTS
IN STEAM BOILERS TO PREVENT THEIR PRIMING," upon the condition
(amongst others) that I, the said Martyn John Roberts, my executors
5 or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
O the date of the said Letters Patent.
NOW KNOW YE, that I, the said Martyn John Roberts, 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, reference being had to the accom-
5 panying Drawings, and to the lotters of reference marked thereon, that
is to say :-
My Invention has for object the prevention of priming in steam
boilers. Many attempts have been made to overcome this evil, such for
example as leading the steam through tortuous passages on its way
O from the boiler to the engine cylinder, but none of them have been
successful, because the velocity with which the water and scum or dirt
are raised with the steam is not sufficient to give them the requisite
momentum to separate them from the steam.
Now according to my Invention I give the requisite velocity and
dist ontifioially Tnass the steam.

page_text: water, and scum or dirt which rise from the boiler through an apparatus
somewhat similar to a centrifugal drying machine, which revolving
thereby gives a centrifugal force to all vapour, liquid, or solid matter
that may enter it. The water and scum or dirt being so very many
times heavier than the steam their centrifugal force will be so many
times greater than that of the steam, so that if there be apertures for a
tangential escape the water and scum will effectually separate themselves
from the steam.
The manner in which my Invention may be carried into effect is as
follows: Upon the top of the boiler I fix a dome or case, to the top of
which I connect the steam pipe leading to the cylinders. Within this
dome I place a circular box, which I call the separator, made to revolve
with sufficient velocity by means of a spindle driven by the engine.
The circumference of this box is open entirely or partially, and near the
top of the box is a concentric horizontal partition, the diameter of which
is less than that of the box, and serves as a guide for the passago or
course of the steam. The box is provided with radial partitions to
ensure an angular motion to the steam, water, and dirt. The bottom of
the box communicates at its centre with the steam space in the boiler,
and the top communicates at its centre with the steam pipe. The
steam and the water and dirt which it may carry with it enter the
bottom of the rapidly revolving box, and acquire great centrifugal force
before they reach the outer edge of the horizontal partition. The steam
from this point rushes to the cylinders, where there is a minus pressure
compared with the boiler pressure, while the water and dirt are ejected
through the open portion of the circumference of the box and return to
L

page_text: central tube at the bottom of the box D, forming a lower journal
thereof, and fitting into a corresponding gland I, which forms the lower
bearing; K is an upper tube, which forms the upper journal. The box
is open either entirely or partially at its periphery, and is divided by
radial partitions L, L. M is a concentric horizontal partition of smaller
diameter than the box D. Rapid rotary motion being communicated to
the box D by means of the pulley G the steam and the water and dirt
which it may carry with it receive on entering the box through the tube
or centre H great centrifugal force, the partitions L ensuring the
requisite angular motion.
While the steam following the course indicated by the arrows rushes
through the pipe C to the cylinders as before explained, the water and
dirt having a much greater centrifugal force become separated from the
steam, are ejected through the open side of the box, and fall into the
bottom of the dome B, finding their way back to the boiler by the pipes N
or otherwise.
Instead of the partitions L forming true radii, as shewn in the
Drawings, they may be placed out of the radial line, and be either
straight or curved, and instead of being vertical they may be set at an
inclination so long as they will ensure a sufficient angular motion to the
steam, water, and dirt; and in cases where the draught or suction to
the cylinders is sufficient to impart the requisite rapidity to the box by
its action upon a fan or other contrivance for turning the box or
separator, the shaft or spindle E nced not be carried to the exterior, the
pulley G being dispensed with.
Figure 3 is a vertical section, and Figure 4 a horizontal section
through the line a, b, of Figure 3 of a modified arrangement, in which
the requisite rapidity is imparted to the separator by the action of the
steam upon a fan as just stated. O is the fan situated at the top of the
separator D and carried on the same shaft E.
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,
constructing or providing steam boilers with a revolving apparatus,
substantially as herein-before described, through which the steam and
the extraneous matters mixed therewith are caused to pass for the

page_text: purpose of separating such extraneous matters from the steam and
thereby preventing priming.
In witness whereof, I, the said Martyn John Roberts, have herc-
unto set my hand and seal, this Second day of May, in the
year of our Lord One thousand eight hundred and seventy-
six.