IM- PROVEMENTS IN THE CONSTRUCTION OF STEAM BOILERS WITH HANGING TUBES, MORE PARTICULARLY AS REGARDS THE SAID TUBES
Year: 1874

page_text: LETTERS PATENT to Johannes Detlef Fürst Hald, of Great Winchester
Street Buildings, in the City of London, for the Invention of "IM-
PROVEMENTS IN THE CONSTRUCTION OF STEAM BOILERS WITH HANGING TUBES,
MORE PARTICULARLY AS REGARDS THE SAID TUBES."-A communication
from abroad by Carl Ångström and Ernst Wiman, both of
Stockholm, in the Kingdom of Sweden.
Scaled the 2nd March 1875, and dated the 9th September 1874.
PROVISIONAL SPECIFICATION left by the said Johannes Detlef Fürst
Hald at the Office of the Commissioners of Patents, with his
Petition, on the 9th September 1874.
I, JOHANNES DETLEF FÜRST HALD, of Great Winchester Street
Buildings, in the City of London, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF STEAM BOILERS
WITH HANGING TUBES, MORE PARTICULARLY AS REGARDS THE SAID TUBES," (a
communication to me from abroad by Carl Ångström and Ernst Wiman,
both of Stockholm, in the Kingdom of Sweden), to be as follows:-
The main object of this Invention is to effect a separation of the outer

page_text: hot ascending and the inner cooler descending currents in hanging
tubes exposed externally to the heat of the fire or products of com-
bustion in vertical and other steam boilers, and by this separation to
prevent the direct cooling of the steam contained in such ascending
currents, and generally to afford a more regular or more effective cir-
culation. As is well known these hanging tubes are closed at the
bottom, and have each an internal tube reaching nearly to the bottom.
Now according to this Invention each tube is fitted with a head, cowl,
or tubular guiding piece consisting of a bell-mouth shaped conical or
otherwise shaped tubular bend attached to the inner tube and formed in
one with an outer tubular slanting continuation of the outer tube, all so
arranged that the cool current passes down the inner tube through the
said bend and the hot current ascends from the outer tube through the
said tubular slanting continuation of the said outer tube, and so that the
entrance for the said inner current is opposite to the exit for the outer
current, or nearly so. The head may be fastened to the tube plate by
means of a flange or lugs and two or three screws, and the inner tube
should have feathers or wings to steady it against the force of the
currents.
By suitable arrangement of the position of the heads aforesaid with
regard to the direction of the inlets and outlets of same, an improved
and constant circulation is obtained, and with this view the heads may
be fitted each with a guide wall or partition fitted between the inlet
and outlet openings in order thereby to separate the currents still more
as required.
It is obvious that the "head" just described may be formed with more
than one inlet or more than one outlet if desired. Also that the said
partitions or guide walls may be fixed to other parts of the boiler than
the tube heads.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Ninth day of September, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs, and successors,
give and grant unto me, the said Johannes Detlef Fürst Hald, Her
special licence that I, the said Johannes Detlef Fürst Hald, my
executors, administrators, and assigns, or such others as I, the said
Johannes Detlef Fürst Hald, 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 THE CONSTRUCTION OF STEAM
BOILERS WITH HANGING TUBES, MORE PARTICULARLY AS REGARDS THE SAID TUBES,"
(a communication to me from abroad by Carl Ångström and Ernst
Wiman, both of Stockholm, in the Kingdom of Sweden), upon the con-
dition (amongst others) that I, the said Johannes Detlef Fürst Hald,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and scals, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Johannes Detlef Fürst Hald, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement, reference being had to the
accompanying Drawings and to the letters of reference marked thereon,
that is to say :-
The main object of this Invention is to effect a separation of the outer
hot ascending and the inner cooler descending currents in hanging
tubes exposed externally to the heat of the fire or products of com-
bustion in vertical and other steam boilers, and by this separation to
prevent the direct cooling of the steam contained in such ascending
5 currents, and generally to afford a more regular or more effective
circulation.

page_text: And in order that this Invention may be more fully ascertained, I
will now proceed to describe the same with reference to the accom-
panying Drawings, of which Figure 1 is a vertical section; Figure 2, a
side elevation; and Figure 3, a plan of a hanging tube with its inner
circulating tube constructed according to this Invention and applied to
a horizontal boiler tube plate. As is well known these hanging tubes e
are closed at the bottom, and have each an internal tube d reaching
nearly to the bottom. Now according to this Invention each tube is
fitted with a “head, cowl, or tubular guiding picce a, b, consisting of a
bell-mouth shaped conical or otherwise shaped tubular bend b attached
to the inner tube d, and formed in one with an outer tubular slanting
continuation a of the outer tube e, all so arranged that the cool current
passes down the inner tube d through the said bend b, and the hot.
current ascends from the outer tube e through the said tubular slanting
continuation a of the said outer tube e, and so that the entrance for the
said inner current is opposite to the exit for the outer current or nearly
SO. The head may be fastened to the tube plate by means of a flange ƒ,
as here shown, or by means of lugs and two or three screws, and the
inner tube d should have feathers or wings to steady it against the force
of the currents.
By suitable arrangement of the position of the heads aforesaid with
regard to the direction of the inlets and outlets of same an improved and
constant circulation is obtained, and with this view the heads may be
fitted each with a guide-wall c, or walls or partitions fitted between the
inlet and outlet openings, in order thereby to separate the currents still
more as required.
It is obvious that the “head” just described may be formed with more
than one inlet or more than one outlet if desired. Also that the said
partitions or guide walls may be fixed to other parts of the boiler than

page_text: Secondly. Constructing hanging steam boiler tubes with heads or
cowls, and if desired, with guide plates, all as set forth.
In witness whereof, I, the said Johannes Detlef Fürst Hald, have
hereunto set my hand and seal, this Eighth day of March, in
the year of our Lord One thousand eight hundred and seventy-
five.
JOHANNES DETLEF FÜRST HALD. (L.S.)