IMPROVEMENTS IN HIGH-PRESSURE STEAM GENERATORS
Year: 1875

page_text: LETTERS PATENT to William John Clark, of Southwick Engine
Works, Southwick, near Sunderland, in the County of Durham, for
the Invention of IMPROVEMENTS IN HIGH-PRESSURE STEAM GENERATORS.
PROVISIONAL SPECIFICATION left by the said William John Clark
at the Office of the Commissioners of Patents, with his Petition,
on the 30th December 1875.
I, WILLIAM JOHN CLARK, of Southwick Engine Works, Southwick,
near Sunderland, in the County of Durham, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN HIGH-PRESSURE STEAM
GENERATORS," to be as follows:-
This Invention has for its object improvements in that class of steam.
generators known as water tube boilers, i.c., boilers in which the fluid is
inside the tubes and the heat applied externally.
The Invention consists in the manner in which the water tubes are
grouped together, so that their ends terminate in two larger tubes or
chambers by which ready access is gained to them for the purpose of
their internal inspection or repair, and in making the steam space of the
boiler available for the purpose of renewing the .tubes.
In the arrangement which I prefer the tubes are placed vertically.

page_text: The lower chamber is made of wrought iron and of a conical form. The
bottom, which is hemispherical, is rivetted in, so also is the top, but
which is flat and perforated to receive the tubes which extend from the top
of the chamber to the bottom of the
chamber. This upper
upper
chamber
is of similar construction but cylindrical, with a domed top and a flat
bottom perforated to receive the tubes, which are made fast and tight in
such a manner as to stay the tube plate. I prefer that the tubes should
be swelled at the upper end to allow the tubes to pass through the upper
tube plate, and both ends screwed with a continuous thread. The holes
in both tube plates being tapped the tubes can then be screwed into
both tube plates.
The upper chamber is made somewhat longer than the tubes, and
admittance is gained into it through a man-hole door. The tubes can
thus be readily withdrawn and replaced by new ones, whilst the upper
chamber affords large steam space. Otherwise the upper chamber may
be kept shorter and the dome end made removable by being bolted on
to a faced flange made or rivetted on to the chamber.
The group of tubes is so set that the heat of the furnace plays first
upon the sides of the lower chamber and afterwards upon the exterior of
the tubes.
The lower chamber being coned admits of a ready escape of steam
from the surface of the plate, and diminishes somewhat the surface area
of the bottom which projects below the flue, and which is thus not acted
on by the heat of the furnace, but forms a mud trap. Entrance to the
lower chamber is likewise made through a man-hole below the flue.
Internal circulating pipes are placed in the inside of the tubes, and an
external pipe also connects the upper and lower chambers.
The number of tubes in each group may be varied and the number
of groups increased according to the evaporative power required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 30
filed by the said William John Clark in the Great Seal Patent
Office on the 29th June 1876.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of December, 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,
3 give and grant unto me, the said William John Clark, Her special
licence that I, the said William John Clark, my executors, admini-
strators, and assigns, or such others as I, the said William John
Clark, my executors, administrators, and assigns, should at any time
agree with and no others, from time to time and at all times thereafter
O during the term therein expressed, should and lawfully might makc,
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 HIGH-PRESSURE STEAM GENERATORS," upon the condition
(amongst others) that I, the said William John Clark, my executors or
5 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 Scal Patent
Office within six calendar months next and immediately after the date
0 of the said Letters Patent.
NOW KNOW YE, that I, the said William John Clark, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
5 This Invention has for its object improvements in that class of steam
generator known as water tube boilers, i.e., boilers in which the fluid is
inside the tubes and the heat applied externally.
The water tubes are grouped together so that their ends terminate in
two larger tubes or chambers by which ready access is gained to them.
0 for the purpose of their internal inspection or repair, and the steam
space of the boiler is made available for the purpose of renewing the
tubes.
In the arrangement which I prefer the tubes are placed vertically, the
lower chamber is made of wrought iron and of a conical form. The
5 bottom, which is hemispherical, is rivetted in, so also is the top, but
which is flat and perforated to receive the tubes, which extend from
the top of the chamber to the bottom of the upper chamber. This

page_text: upper chamber is of similar construction but cylindrical, with a domed
top, and a flat bottom perforated to receive the tubes which are made
fast and tight in such a manner as to stay the tube plate. I prefer
that the tubes should be swelled at the upper end to allow the tubes
to pass through the upper tube plate, and both ends screwed with a
continuous thread. The holes in both tube plates being tapped tho
tubes can then be screwed into both tube plates.
The upper chamber is made somewhat longer than the tubes, and
admittance is gained into it through a man-hole door. The tubes can
thus be readily withdrawn and replaced by new ones, whilst the upper 1
chamber affords large steam space.
Otherwise the upper chamber may
be kept shorter, and the dome end made removable by being bolted on
to a faced flange made or rivetted on to the chamber.
The group of tubes is so set that the heat of the furnace plays first
upon the sides of the lower chamber, and afterwards upon the exterior 1
of the tubes.
The lower chamber being coned admits of a ready escape of steam.
from the surface of the plate, and diminishes somewhat the surface arca
of the bottom which projects below the fluc, and which is thus not acted
on by the heat of the furnace, but forms a mud trap. Entrance to the 2
lower chamber is likewise made through, a man-hole below the flue.
Internal circulating pipes are placed in the inside of the tubes, and an
external pipe also connects the upper and lower chambers.
The number of tubes in each group may be varied and the number of
2
groups increased, according to the evaporative power required.
In order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawings
hereunto annexed.

page_text: a, a, are two sets of water tubes. The tubes of each set at their lower
cuds are screwed into a tube plate forming the top of the chamber 6 of
which the side is conical and the bottom hemispherical. At their upper
ends the tubes of each set are screwed into another tube plate forming
the bottom of the chamber c, which is cylindrical and has a domed top
serving as a steam space. The chamber c is provided with a man-hole,
and it can be entered when necessary for the purpose of removing and
replacing the tubes; d, d, are circulating tubes which may be placed
inside the tubes a, as is now practiced in other water tube boilers; e is
a cast-iron support on which the boiler stands, and there are passages
formed through it by which the boiler is emptied or blown out; fis a
pipe connecting the chambers b and c to assist the circulation of the
boiler, and the feed water connection is made with this pipe; 9 is the
furnace; the heat from the furnace impinges first on the sides of the
chambers b, b, which are set in the fluc h, and then ascending to
the upper flue i it heats the water tubes a; k is the chimney.
Having thus described the nature of my Invention and the manner of
performing the same, I would remark that the arrangement of the
furnace and setting may be varied without departing from my Invention,
and so may also the number of sets of which the boiler is composed and
the form of the chambers b and c. I would also remark that my
Invention is confined to water tube boilers, that is to say, to tubular
boilers in which the water is contained within the tubes. I claim com-
bining the water tubes with other larger tubes or chambers, so as to
secure easy access to them for renewal or repair, substantially as
described.
In witness whereof, I, the said William John Clark, have hereunto