IMPROVEMENTS IN APPARATUS FOR SUPER- HEATING STEAM
Year: 1859

page_text: LETTERS PATENT to Joshua Field, of Lambeth, in the County of Surrey,
Engineer, for the Invention of "IMPROVEMENTS IN APPARATUS FOR SUPER-
HEATING STEAM."
Sealed the 28th February 1860, and dated the 30th August 1859.
PROVISIONAL SPECIFICATION left by the said Joshua Field at the
Office of the Commissioners of Patents, with his Petition, on the 30th
August 1859.
I, JOSHUA FIELD, of Lambeth, in the County of Surrey, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN APPA-
RATUS FOR SUPERHEATING STEAM," to be as follows:-
The steam is made to pass through a system of flattened tubes, which are
placed so as to offer less resistance to the heated gases, and give a greater
area for their passage, while at the same time the surface of the tubes is
brought into better contact with the heat. The tubes are so arranged that
any of them may be easily repaired or replaced when required, and they may.
easily cleaned or kept free from soot.
by the said Joshua Field in the
February 1860.
Dear
оп сце
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSHUA
FIELD, of Lainbeth, in the County of Surrey, Engineer, send greeting.
[Price S.]

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of August, in the year of our Lord
One thousand eight hundred and fifty-nine, in the Twenty-third year of Her
reign, did for Herself, Her heirs and successors, give and grant unto me, the
said Joshua Field, Her special licence that I, the said Joshua Field, my
executors, administrators, and assigns, or such others as I, the said Joshua
Field, my executors, administrators, and assignis, 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, excrcise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
APPARATUS FOR SUPERHEATED STEAM," upon the condition (amongst others)
that I, the said Joshua Field, my executors or administrators, by an instru-
ment 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.
IN
NOW KNOW YE, that I, the said Joshua Field, do hereby declare the
nature of my said Invention, and, in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the Drawings hereunto annexed,
that is to say :-
...My. Invention consists of an improved method of arranging and con-
structing apparatus for superheating steam, whereby the steam is made to
pass through a system of flattened tubes, which are placed in the uptake in
such a position as not to interfere with getting at the ends of the boiler tubes
for cleaning or renewing them, and so as to offer the least resistance to the
heated gases, and give the requisite area for their passage to the chimney,
while at the same time the surface of the tubes is brought well into contact
with the heated gases which pass up between them. The tubes are placed in"
rows one above the other, and have their ends fixed into steam boxes, one of
which receives the steam direct from the boilers, while the other has com-
munication with the main steam pipe leading to the engine. The ends of the
flattened tubes are. left round, and are fixed in the tube plates of-the-steam
boxes with ferrules in the ordinary way, but as the flattened. portion of the
tubes will not pass through the round holes in the tube plates, I divide the
tubes into groups of nine, as near as may be, and make the holes in one of
the tube plates for the central tubes of the groups, of such a form and size
**

page_text: as will readily allow the flattened tubes to pass through them, and then bolt
on to the plate small flange plates with round holes, into which the ends of
the tubes are fixed in the ordinary way. By this arrangement any one of the
surrounding tubes may be taken out and renewed, when required, by first
removing the central tube of its group with the flange plate on its end, and
then withdrawing the defective tube through the central hole made for that
purpose. The sides of the tubes, placed in rows above one another, present
a nearly flat surface, which may be readily cleaned with brushes through doors
made in the chimney uptake; but in cases where it is not convenient to.
clean them in that way, I pro pose to use a scraper worked from the outside
for the purpose. Also, in cases where it is convenient to do so, I prefer to
provide additional passages for the heated gases, with the requisite dainpers
for shutting off the passages through the superheating apparatus, which may
be used in case of the apparatus requiring repair, so that it may not be injured:
when it is found necessary to shut the steam off from it.
In the accompanying Drawings I have shewn the general arrangement and
description of my improved apparatus as applied to boilers which have their
stoking places between them; but I do not confine myself to those par-
ticular arrangements, as they will require to be varied to suit the description.
of boilers, to which they may be applied.
Figure 1 is a transverse view, showing the apparatus fixed in the uptake.
above the top of the boiler; one half is shown in section through the centre.
of the apparatus, and the other half is shewn in elevation, with the cover of
the steam-box removed, in order to show the ends of the tubes. Figure 2.
is a longitudinal section, and Figure 3 is a sectional plan, of the same:
apparatus. The same letters of reference indicate like parts in all the Figures.
a, a, are the shut-off and safety-valve boxes fixed on the face of the boilers;
b, b, are the steam boxes, which receive steam from the boilers; c, c, are the:
steam boxes which receive steam from the superheating tubes d, d.. The
steain boxes are united together by the side plates e, e, so as to form a rigid
combination. ff, are valves for shutting the steam off from the superheating
apparatus when required; g,g, are throttle valves placed in the steam pipe,
which valves are shut when the superheating apparatus is in use, in order to
cause the steam to pass in the direction shown by the arrows, and are opened
when the steain is shut off from the superheating apparatus by the valves f,f,
so as to allow it to pass straight along the pipe into the main steam pipe h;
i, i, are doors in the uptake of the chimney, for the purpose of cleaning the
sides of the tubes, and k, k, are gratings hinged to the uptake to form a
platform for the men to stand on; 1, 2, show additional passages provided for

page_text: the heated gases when it is required to shut the steam out of the superheating
tubes, which passages are regulated by the damper m, so as to shut off the
passage through the superheating apparatus, and to open the side passages
which are in communication with the chimney. Each separate apparatus is
provided with a small safety valve, to prevent the danger of explosion, should
any moisture remain in the apparatus when the valves f,f, are shut, which
safety valve may be made to discharge direct into the waste steam chamber
of the safety valve box on the boiler, as shown in the Drawing at n, or into
the boiler itself, in which case a much smaller amount of load will be required
on the valve. Figure 4 shows in end view and longitudinal section respec-
tively enlarged views of one group of the superheating tubes, with the holo
in the centre for withdrawing the tubes and the flange plate, into which one
end of the central tube is fixed. Figure 5 is a transverse view partly in
section and partly in elevation, of the apparatus when applied below the top
of the boiler, to keep it out of the way of shot. A double partition is shown
on the outside at a, a, into which the feed water may be pumped, in order
to raise its temperature before it enters the boiler. In this arrangement the
sides of the flattened tubes may easily be cleaned through the ordinary smoke
doors.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I do not claim as my
improvements in apparatus for superheating steam the einployment of flat
tubes, as such tubes were used for the purpose of superheating steam by the
firm of which I am a member in March 1858, and which were placed in the
smoke box opposite to the spaces between the different rows of tubes; but
what I claim is, the particular apparatus, shown in the Drawings, placed in
the uptake as near as convenient to the ends of the boiler tubes, in manner
and for the purposes herein-before described.
In witness whereof, I, the said Joshua Field, have hereunto set my
hand and seal, this Twenty-eighth day of February, One thousand
eight hundred and sixty.
JOSHUA FIELD. (1.8.)