IMPROVEMENTS IN SURFACE BLOW-OFFS FOR STEAM BOILERS
Year: 1860

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Loughborough Park,
Brixton, in the County of Surrey, for the 'Invention of "IMPROVEMENTS IN
SURFACE BLOW-OFFS FOR STEAM BOILERS."-A communication from abroad by
E. S. Renwick, of 835, Broadway, New York, United States of
America.
Sealed the 26th February 1861, and dated the 27th August 1860.
PROVISIONAL SPECIFICATION left by the said George Tomlinson Bous-
field at the Office of the Commissioners of Patents, with his Petition, on
the 27th August 1860.
I, GEORGE TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the
County of Surrey, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN SERVICE BLOW-OFFS FOR STEAM BOILERS," to be as follows:-
The object of this Invention is to provide an efficient means of blowing-off
at the surface of the water in steam boilers without requiring the services of
the engineer or fireman for the purpose; and the Invention consists in com-
bining a steam boiler with a self-acting trap that will permit the escape of
water but.retain steam by means of a pipe, one of whose orifices is at the level
of the surface of the water in the boiler, while the other orifice communicates.
with the self-acting trap.

page_text: The best mode with which I am acquainted of carrying this Invention into
effect, consists of a tight vessel forming a float chamber, and having a pipe
that descends in the float chamber. This pipe terminates at its upper end in a
passage through which the water is discharged; it terminates at its lower end
in a valve chest, having two orifices, to which conical valves are fitted. The
two valves are secured to a valve stem, which ascends to a guide, and is
secured at its upper end to a float. The float has the form of a cylindrical
vessel that is closed at its bottom and open at its top, and it is fitted to move
freely up and down in-the float chamber without changing its upright position,
and is of less diameter than the float chamber, so that an annular space is left
round the float. When the float is moved downwards in the chamber, it
depresses the valve stem, which is secured to it, and opens the conical valves;
when it is moved upwards in the chamber it, raises the valve 'stem and closes
the valves. The trap is connected with the steam boiler by means of a pipe
which enters the boiler and at its orifice therein, located at about the level at
which the water in the boiler is to be maintained, so that whenever the water
in the boiler rises above this-level the surplus enters the connecting pipe and
passes to the trap. The connecting pipe is fitted with a stop-cock, by means
of which the passage of steam or water from the boiler to the trap can be
prevented when the trap is to be opened for repair or for other purposes.
In order to start the apparatus thus described, sufficient water should be
introduced into the trap to fill the annular space around the float, and cause
the latter, by reason of its buoyancy; to bear the valves against their seats,
thus keeping them closed. When the steam boiler is in operation, any surplus
of water above the orifice of the connecting pipe passes through the pipe into
the trap, and collects in the interior of the float. This collection of surface
water from the boiler goes on until a sufficient quantity has accumulated in
the float to cause it to sink in the vessel, in doing which it opens the valves
and permits the pressure of steam from the boiler to blow the accumulated
water out of the float from the bottom thereof through the pipe and passage
first mentioned. As the water is blown out' the-float regains, its buoyancy,
and rising closes the valves before the water is blown-off sufficiently low to.
permit the steam which follows the water to escape. When the float has thus
stopped the flowing off of the water, the valves remain closed until the surface
water from the boiler again accumulates in the float sufficiently to open the
valves. The apparatus thus constitutes a self-acting 'surface blow-off for the
steam boiler that permits the water to escape, and retains the steam; and if
more feed water be fed into 'the boiler than is required to make steam, the
excess is discharged from the surface of the water in the boiler by the trap.
.1

page_text: without waste of steam, so that an undue accumulation of water in the boiler.
is prevented. With a boiler working, sea water it is believed that it will be
advantageous to supply the feed water to the. boiler in excess, so that the
surface water may be continually blown off, as by this means no danger will
arise from the water getting too low in the boiler, the saturation of the water
in the boiler with salt will be prevented, and the fine particles of scale which
are. thrown to the surface by the bubbles of steam will be discharged from
the boiler.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Tomlinson Bousfield in the Great Seal Patent
Office on the 27th February 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE.
TOMLINSON BOUSFIELD, of Loughborough Park, Brixton, in the County of
Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of August, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,,
did, for Herself, Her,heirs and successors, give and grant unto me, the said
George Tomlinson Bousfield, Her special licence, that I, the said George
Tomlinson Bousfield, my executors, administrators, and assigns, or such
others as I, the said George Tomlinson Bousfield, my executors, adminis-
trators, 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 Chaunel Islands, and Isle of Man, an
Invention. for." IMPROVEMENTS IN SURFACE BLOW-OFFS FOR STEAM BOILERS," a
communication to me from abroad by E. S. Renwick, of 335, Broadway,
New York, United States of America, upon the condition (amongst others):
that I, the said George Tomlinson Bousfield, my executors 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 the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Tomlinson Bousfield, do hereby:
declare the nature of the said- Invention, and in what manner the same is;

page_text: to be performed;. to be particularly described and ascertained in and by the fol-
lowing statement thereof;ireference being had to the accompanying Drawing,
which represents, a vertical. transverse: section of a steam boiler with.. the
improved surface blow-off applied thereto. ¡ .
...
The object of this Invention is to provide an efficient means of blowing-off
at the surface of the water in steam boilers without, requiring the attention of
an engineer or fireman, and without unnecessary waste of steam; and the
Invention consists in combining with a steam boiler a self-acting trap that
will permitithe escape of water, but will retain steam by means of a pipe, one
of whose orifices is at the usual level of the surface of the water in the boiler
or thereabouts, while the other orifice communicates with the self-acting trap.
The accompanying Drawing represents an example of the best mode with
which I am acquainted of carrying the Invention into effect. In this example
the trap A consists of a tight vessel forming a float chamber and having a
pipe b, that descends in the float chamber from the bonnet c thereof. This
pipe terniinates at its upper end in-a-passage d, through: which the...water.
received from the boiler is discharged; it terminates at its lower end in a valvē
chest f; having two orifices, to which conical valves e, e, are fitted. The two valves
áre secured to a valve stem which ascends through a guide lug made fast to.tbe
pipe b, and is secured at its upper end to a float g. The float (9) has the form
of a cylindrical vessel, that is closed at its bottom and open at its top, so.that
the water can pass freely into the upper end; it is fitted to move freely up and
down in the float chamber without changing its upright position, and is of less
diameter than the float chamber, so that an annular, space i, is left around the
float. The sides of this float surround the discharge pipe 6, the valve chest.fi.
and the valve stem.j, which project downwards into the interior of the float:
within a short distance of its bottom, a; sufficient space being left beneath the
valve chest to permit the float to rise and fall freely, a sufficient distance, to
close and open the valves. When the float is moved downwards in the
chamber it depresses the valve stem j; which is secured to it and opens the
conical valves, when it is moved upwards in the chamber it raises the valve.
stem and closes the valves. The trap A, is connected with the steam boiler B,
by means of pipe. M, which enters, the boiler and has its orifice therein (n,)
located at the level at which the water in the boiler is to be maintained, so
that whenever the water in the boiler rises above the level, the surplus can
enter the connecting pipe and pass into the trap. The connecting pipe is
fitted with a stop cock by means of which the passage of steam or water
from the boiler, to the trap, can be prevented when the trap is to be opened
for repair or for other purposes. In order to start the apparatus thus described

page_text: into operation sufficient water should be introduced into the trap to fill the
annular space around the float, and cause the latter by reason of its buoyancy,
to-bear the valves against their seats, thus keeping them closed.. When the
steam boiler is in operation any rise of the water above the orifice of the con-
necting pipe M, causes a flow thereof through the pipe into the trap and over
the upper edge of the float, and the water collects in the interior of the float.
This collection of surface water from the boiler goes on until a sufficient
quantity has, accumulated in the float to cause it to sink in the chamber, in
doing which it opens the valves e, e, and permits the pressure from the boiler to
blow the accumulated water out of the float through the pipe 6, and passage d;
as the water is blown out, the float regains its buoyancy, and rising closes
the valves before the water in the float is blown off down to the level of the.
upper valve which would permit :the steam which follows the descent of the
water in the float to escape. When the float, by thus rising, has stopped the
blowing off of the water the valves remain closed until the surface water from.
the boiler again accumulating in the float sufficiently to depress the float and
open the valves. The apparatus thus constitutes a self-acting surface blow
off for the steam boiler that permits the water to escape, but retains the steam.
If more water should be fed into the boiler than is required to make steam,
the excess will be discharged from the surface of the water in the boiler by
the trap without waste of steam, so that an undue accumulation of water in
the boiler is prevented. With a boiler working sea water it is believed that it
will. be advantageous to supply the feed water to the boiler in excess, so that
the surface water may be continually blown off, as by this means no danger will
arise from the water getting too low in the boiler, the saturation of the water
in the boiler with salt will be prevented and the fine particles of scale which
are thrown to the surface by the bubbles of steam will be discharged from
the boiler into the trap and thence blown off.
:
Having thus described one mode of carrying the Invention into effect, it is
proper to state that I do not claim any one of the three elements of the com-
bination, when separated from the other two, as the Invention I'desire to
secure by Letters Patent, nor is the Invention confined to the particular
construction of any of its parts, as these may be varied to suit the exigencies
of any particular case, or the views of the engineers who apply this Invention,
it being essential only that the trap used be one that will permit the discharge
of water and retain steam, and that the orifice of the connecting pipe shall be
in a position to receive the surface water of the boiler. Neither do 'I claim
to be the first who has combined boilers with self-acting surface blow-off's
as I am aware that a valve has been placed near the surface of the water

page_text: in a boiler and has been combined with a float in the boiler which opens
the valve when the water rises. But what I claim as. the. Invention and
desire to secure by Letters Patent is the, combination of a steam boiler
-with a trap that will; permit the escape. of 'water and retain steam by means
of a. connecting: pipe, one of whose orifices is at the level of the surface of
.thewater in the boiler, substantially as described.
In "witness whereof, "I, the said George Tomlinson Bousfield; have
hereunto set my hand and seal, this Eleventh day of February
in the year of our. Lord One thousand eight hundred and sixty-one.
GEO. T. BOUSFIELD G