Im- PROVEMENTS IN STEAM PUMPS
Year: 1873

page_text: LETTERS PATENT to Thomas Henderson Forrest, of Irvine, in the
County of Ayr, North Britain, Engineer, for the Invention of "Im-
PROVEMENTS IN STEAM PUMPS."
Scaled the 16th September 1873, and dated the 21st March 1873.
PROVISIONAL SPECIFICATION left by the said Thomas Henderson
Forrest at the Office of the Commissioners of Patents, with his
Petition, on the 21st March 1873.
I, THOMAS HENDERSON FORREST, of Irvine, in the County of Ayr,
North Britain, Engineer, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN STEAM PUMPS," to be as follows, that is to
say :-
1
This Invention relates principally to steam pumps of the kind in
which the pump which may be either reciprocating or rotating is worked
by means of a special steam cylinder or combination of cylinders; and
consists in fixing in either the delivery or suction pipe of the pump, but
by preference the latter, any suitable modification of apparatus of the
kind known as "injectors" or "ejectors," such apparatus having con-

page_text: nected to it a pipe leading from the exhaust port of the steam cylinder.
With this arrangement the exhaust steam is led into the water set in
motion by the pump, and the exhausting of the steam into the atmo-
sphere or into a special condenser is dispensed with, whilst the action
of the pump is considerably improved. The heat of the exhaust steam
is also imparted to the water which will be an advantage in cases in
which the water has to be heated.
The injector or ejector apparatus preferred in ordinary cases consists
of a nozzle of the full bore of the water pipe, and projecting into an
annular chamber into which the exhaust steams enters, and which
terminates in a conical or conoidal throat merging into the continuation
of the water pipe, but so as to leave a narrow annular inlet for the
steam into the water pipe at the end of the nozzle.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Henderson Forrest in the Great Seal
Patent Office on the 19th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HENDERSON FORREST, of Irvine, in the County of Ayr, North Britain,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of March, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Thomas Henderson Forrest,
Her special licence that I, the said Thomas Henderson Forrest, my
executors, administrators, and assigns, or such others as I, the said
Thomas Henderson Forrest, 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 King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN STEAM PUMPS," upon the con-

page_text: dition (amongst others) that I, the said Thomas Henderson Forrest, 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 Thomas Henderson Forrest, 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 in writing, reference being had to the
accompanying Drawings, that is to say :-
My said Invention relates principally to steam pumps of the kind in
which the pump which may be either reciprocating or rotating is worked
by means of a special steam cylinder or combination of cylinders; and
consists in fixing in either the delivery or suction pipe of the pump, but
by preference the latter, any suitable modification of apparatus of the
kind known as "injectors" or "cjectors," such apparatus having con-
nected to it a pipe leading from the exhaust port of the steam cylinder
or cylinders.
And in order that my said Invention and the manner of performing
the same may be properly understood, I hereunto append a Sheet of
explanatory Drawings to be herein-after referred to, and representing
apparatus as arranged for carrying out my improvements. In these
Drawings the same reference numerals are used for marking the same
or like parts wherever they are repeated.
Figure 1 on the Sheet of Drawings is a side clevation partly in section
showing a horizontal reciprocating pump 1 arranged to be worked by a
direct acting steam cylinder 2. A pipe 3 is led from the exhaust outlet
of the steam cylinder 2 to a casting 4 (shown in section) inserted in the
line of the suction pipe 5, 6, of the pump 1. The middle part of the
casting 4 is pear-shaped so as to form an annular space 7 round a
nozzle 8 which is fixed inside and projects up nearly to the top of the
annular space. The exhaust steam has access in an upward direction
through the annular slit thus left between the top of the nozzle 8 and
the casting 4 to the suction passage, and entering into the upward
stream of water set in motion by the pump accelerates that motion and

page_text: improves the pumping action, whilst the exhausting of the steam into
the atmosphere or into a special condenser is dispensed with. Theh eat
of the exhaust steam is also imparted to the water which will be an
advantage in cases in which the water has to be heated. I prefer the
nozzle 8 of the injector (or ejector) apparatus 4 to be of the full bore of
the pipes 5, 6, as shown. Where there is a considerable lift it may be
desirable on starting the steam pump to shut off the communication by
the pipe 3, and for this purpose a three-way cock 9 is fitted to the
exhaust outlet with a pipe 10 for leading away the steam for a few
strokes at starting.
Figure 2 is a side elevation showing the application of the apparatus 4
to a centrifugal pump 1 worked directly by a steam cylinder 2.
Figure 3 is a section of a modification of the injector or ejector
apparatus which I prefer to use for pumps of large size. The nozzle 8
is perforated with a number of inclined holes which subdivide the steam
and thereby facilitate its commingling with and condensation by the
upward current of water.
Having thus particularly described my said Invention, and the
manner of performing the same, I have to state that I do not restrict
myself to the precise details herein described or delineated, but that
what I believe to be novel and original and claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,
the fitting of "injector" or "cjector" apparatus in the suction or
delivery pipe of a steam pump together with a pipe to lead the exhaust
steam into such apparatus, substantially as herein-before described.
In witness whereof, I, the said Thomas Henderson Forrest, have
hereunto set my hand and seal, this Eighteenth day of September,
in the year of our Lord One thousand eight hundred and seventy-
three.
THOMAS H. FORREST. (L.S.)