IMPROVEMENTS. IN THE CONSTRUCTION OF MULTITUBULAR STEAK BOILERS
Year: 1872

page_text: LETTERS PATENT to Frederick Hazeldine, of Lant Street, Borough,
in the Count of Surrey, for the Invention of “IMPROVEMENTS. IN THE
CONSTRUCTION OF MULTITUBULAR STEAK BOILERS."
Scaled the 28th March 1873, and dated the 3rd October 1872.
PROVISIONAL SPECIFICATION left by the said Frederick Hazeldine
at the Office of the Commissioners of Patents, with his Petition,
on the 3rd October 1872.
I, FREDERICK HAZELDINE, of Lant Street, Borough, in the County
of Surrey, do hereby declare the nature of the said Invention for
“ IMPROVEMENTS IN THE CONSTRUCTION OF MULTITUBULAR STEAM BOILERS," to be.
as follows :-
This Invention is designed to increase the evaporative power of steam
'boilers and to obviate the objection attending the tubes of multitubular
steam boilers arising from the expansion and contraction of the said.
tubes, and by which the points of junction of the said tubes with the
plates of the boiler become loosened and leak at such said parts; I
propose to increase the evaporative power and to remedy the above
j

page_text: objection by the following means, that is say, instead of making the
tubes straight throughout their entire length as now commonly practised
in the construction of multitubular boilers I propose to make the said
tubes curved or bent between their opposite ends, in order that the
expansion and contraction may take place principally at the curved or
bent part of each tube, thus rendering the tubes flexible instead of rigid
during the expansion and contraction thereof, and by these means
preventing leakage and materially increasing the steaming of the boiler
by means of greater length of tubes, as above stated.
i
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Hazeldine in the Great Seal Patent
Office on the 3rd April 1873:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
HAZELDINE, of Lant Street, Borough, in the County of Surrey, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of October, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Frederick Hazeldine, Her special
licence that I, the said Frederick Hazeldine, my exccutors, admini-
strators, and assigns, or such others as I, the said Frederick Hazeldine,
my executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and 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 THE CONSTRUCTION OF MULTITUBULAR STEAK BOILERS," upon the con-
dition (amongst others) that I, the said Frederick Hazeldine, 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.

page_text: NOW KNOW YE, that I, the said Frederick Hazeldine, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertain in and
by the following statement, that is to say i-
-
This Invention is designed to increase the evaporative power of steami
boilers and to obviate the objection attending the tubes of multi-
tubular steam boilers arising from the expansion and contraction of the
said tubes, and by which the points of junction of the said tubes with
the plates of the boiler become loosened and leak at such said parts. Ì
propose to increase the evaporative power and to remedy the above
objection by the following means, that is to say, instead of making the
said tubes straight throughout their entire length is now commonly
practised in the construction of multitubular boilers I propose to make
the said tubes curved or bent between their opposite ends, in order that
the expansion and contraction may take place principally at the curved
or bent part of each tube, thus rendering the tubes flexible instead of
rigid during the expansion and contraction thereof, and by these means
preventing leakage and materially increasing the steaming of the boiler
by means of greater length of tubes, as above stated:
The accompanying Drawing represents an elevation of an upright
multitubular steam boiler, with a portion of the outer shell thereof
broken away to expose to view my improved tubes adapted to a
boiler.
A. marks a series of curved or bent tubes arranged in a helical
or spiral direction; B represents the bottom tube plate to which the
tubes A are connected and affixed, as also to the top tube plate (not
shewn in the Drawing) in the manner usually practised and well known
by manufacturers of upright multitubular boilers, except that the holes
in the top tube plate of the boiler intended to receive the upper ends of
the several tubes A should be made rather larger than the holes in the
bottom tube plate B. I would here observe that the pitch or amount of
bend of the tubes A will vary according to the diameter of the circle of
holes in the tube, sheets, or plates, and the height of the boiler, except
the centre tube, not shewn in the Drawing, which being from 4 to 10
inches in diameter, according to the power of the boiler, is formed
straight, with flanged ends rivetted to the top and bottom tube, sheets,
or plates; in the usual manner. The advantages of the improved curved,

page_text: bent, or spiral tubes over the ordinary straight upright ones are that
they prevent the leaking of the tubes, a constantly recurring evil in
upright boilers, their spring-like form permitting easy expansion and
contraction without affecting their tightness; in the tube sheets they
permit the use of convex lower tube sheets or furnace crowns, thus
tending to prevent the plate from cracking through deposition of silt
and other matters, and they increase largely the heating surface by
having a much longer tube in the same height of boiler, and the heating
surface is of a more effective description, being made to approach as
much as possible the best of all heating surface, the horizontal tube,
excepting in the steam way or part of tube above the water line
which is straight and consequently upright or nearly so. The ordinary
tube brush may be used with my improved curved, bent, or spiral
tubes.
Having now described the nature of my said Invention for "Improve- ]
ments in the Construction of Multitubular Steam Boilers," and the
means by which it may be effected, I desire it to be understood that I
hereby declare my Invention to consist in, and I claim constructing
upright multitubular steam boilers with curved or bent pipes in lieu of
straight pipes as heretofore employed for the purpose of increasing the 2
heating surface and evaporating power of the boiler without increasing
the height thereof, also for preventing leakage of the tubes of the boiler
at their points of junction with the tube sheets, as above described.
In witness whereof, I, the said Frederick Hazeldine, have hereunto
set my hand and seal, this Second day of April, in the year of 2
our Lord One thousand eight hundred and seventy-three.